diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
| commit | 034dd340b08be1f2f0477ad16131d609f9dbd53c (patch) | |
| tree | 2536f4b2d7893ccd916b5abdf3c454ad6edc03c2 /arch/x86/boot | |
| download | linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.tar.gz linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.zip | |
Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt:
- Fix error output of boot instance creation failure
Currently if a boot instance creation fails, instead of printing out
the name of the instance that failed, it prints "(null)". That is
because it prints "cur_str" that had already been processed by
strsep(). Print the saved name instead.
While at it, print the error code of the failure.
- Fix use-after-free for same named historgrams
Histograms can be named so that they can be used in multiple events.
But if the named histogram has a variable attached, the second event
that uses the named histogram which duplicates it and needs to free
the original after duplication leaves the old variable in place and
still visible. If another histogram uses than variable, it will use
the stale one which will try to reference the freed duplicate
histogram and crash the kernel.
Free the duplicate variables along with the duplicated histogram
data.
- Check return value of kthread_run() in event self test
The events self tests uses a kthread for testing but does not check
if it succeeded in creating a kthread. If the kthread creation were
to fail, the code will still try to call kthread_stop() on the error
returned.
- Fix race between reading trace_pipe and updating subbuffer size
If a user is reading the trace_pipe file at the same time they update
the ring buffer sub-buffer size, can cause the trace_pipe read to
read stale data. Add trace_access_lock() around updating the ring
buffer sub-buffer size.
- Fix eventfs_inode on failure path in creation of the events directory
In the creation of the "events" directory, if after allocating the
eventfs_inode a failure is detected, it calls cleanup_ei() which
calls free_ei(). The free_ei() will test if eventfs_inode being freed
has no children. It is a bug if it does. But on the failure case of
the creation of the "events" directory, the children lists have not
yet been initialized and the free will trigger a warning because
list_empty() on an uninitialized list returns false.
Move the initialization into init_ei() where it makes more sense and
makes sure that a created eventfs_inode has its lists initialized
upon creation.
- Check return value of kthread_run() in ftrace direct sample code
The sample code that shows how to use the ftrace direct calls does
not test the return of kthread_run() to see if it succeeds. Return a
failure if the kthread_run() doesn't succeed.
- Clear user events state on fork in case of alloc failure
On fork, the child gets a pointer to the parent's user events state.
It makes a copy of it then updates the child's pointer to it. But if
the allocation fails, the duplication function leaves the child with
a pointer to its parent's descriptor. When the child cleans up its
data, it will free the parent's descriptor while the parent is still
using it.
In the duplication function, set the child's user_event_mm to NULL
before testing if the allocation succeeded, and when it exits it will
not free the parent's descriptor.
- Fix retry exhaustion in simple ring buffer reader swap
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a
failed replacement leaves it at -1.
But the check for success expects the retry value to be non-zero and
exits with an error on zero. This is the opposite result. Fix it.
- Fail nicely when the remote swap_reader_page() returns an error
Currently, if the swap_reader_page() of a remote buffer fails, it
triggers a WARN_ON_ONCE() and continues normally. Instead, have it
exit with an error and a pr_warn() print instead of a full WARNING.
* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Stop remote reader update when page swap fails
tracing: Fix retry exhaustion in simple ring buffer reader swap
tracing/user_events: Clear copied tracing state before fork duplication
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
eventfs: Initialize ei->children and ei->list in init_ei()
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
tracing: Fix crash passing ERR_PTR to kthread_stop()
tracing: Fix use-after-free with same-name named triggers
tracing: Fix logged instance name on creation failure
Diffstat (limited to 'arch/x86/boot')
82 files changed, 13708 insertions, 0 deletions
diff --git a/arch/x86/boot/.gitignore b/arch/x86/boot/.gitignore new file mode 100644 index 000000000..070ef534c --- /dev/null +++ b/arch/x86/boot/.gitignore @@ -0,0 +1,15 @@ +# SPDX-License-Identifier: GPL-2.0-only +bootsect +bzImage +cpustr.h +mkcpustr +voffset.h +zoffset.h +setup +setup.bin +setup.elf +fdimage +mtools.conf +image.iso +hdimage +tools/ diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile new file mode 100644 index 000000000..3f9fb3698 --- /dev/null +++ b/arch/x86/boot/Makefile @@ -0,0 +1,139 @@ +# +# arch/x86/boot/Makefile +# +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (C) 1994 by Linus Torvalds +# Changed by many, many contributors over the years. +# + +# If you want to preset the SVGA mode, uncomment the next line and +# set SVGA_MODE to whatever number you want. +# Set it to -DSVGA_MODE=NORMAL_VGA if you just want the EGA/VGA mode. +# The number is the same as you would ordinarily press at bootup. + +SVGA_MODE := -DSVGA_MODE=NORMAL_VGA + +targets := vmlinux.bin setup.bin setup.elf bzImage +targets += fdimage fdimage144 fdimage288 image.iso hdimage +subdir- := compressed + +setup-y += a20.o bioscall.o cmdline.o copy.o cpu.o cpuflags.o cpucheck.o +setup-y += early_serial_console.o edd.o header.o main.o memory.o +setup-y += pm.o pmjump.o printf.o regs.o string.o tty.o video.o +setup-y += video-mode.o version.o +setup-$(CONFIG_X86_APM_BOOT) += apm.o + +# The link order of the video-*.o modules can matter. In particular, +# video-vga.o *must* be listed first, followed by video-vesa.o. +# Hardware-specific drivers should follow in the order they should be +# probed, and video-bios.o should typically be last. +setup-y += video-vga.o +setup-y += video-vesa.o +setup-y += video-bios.o + +targets += $(setup-y) +hostprogs += mkcpustr + +HOST_EXTRACFLAGS += -I$(srctree)/tools/include \ + -include include/generated/autoconf.h \ + -D__EXPORTED_HEADERS__ + +$(obj)/cpu.o: $(obj)/cpustr.h + +quiet_cmd_cpustr = CPUSTR $@ + cmd_cpustr = $(obj)/mkcpustr > $@ +$(obj)/cpustr.h: $(obj)/mkcpustr FORCE + $(call if_changed,cpustr) +targets += cpustr.h + +# --------------------------------------------------------------------------- + +KBUILD_CFLAGS := $(REALMODE_CFLAGS) -D_SETUP +KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables +KBUILD_CFLAGS += $(CONFIG_CC_IMPLICIT_FALLTHROUGH) + +$(obj)/bzImage: asflags-y := $(SVGA_MODE) + +quiet_cmd_image = BUILD $@ + cmd_image = (dd if=$< bs=4k conv=sync status=none; cat $(filter-out $<,$(real-prereqs))) >$@ + +$(obj)/bzImage: $(obj)/setup.bin $(obj)/vmlinux.bin FORCE + $(call if_changed,image) + @$(kecho) 'Kernel: $@ is ready' ' (#'$(or $(KBUILD_BUILD_VERSION),`cat .version`)')' + +OBJCOPYFLAGS_vmlinux.bin := -O binary -R .note -R .comment -S +$(obj)/vmlinux.bin: $(obj)/compressed/vmlinux FORCE + $(call if_changed,objcopy) + +SETUP_OBJS = $(addprefix $(obj)/,$(setup-y)) + +sed-zoffset := -e 's/^\([0-9a-fA-F]*\) [a-zA-Z] \(startup_32\|efi.._stub_entry\|efi\(32\)\?_pe_entry\|input_data\|kernel_info\|_end\|_ehead\|_text\|_e\?data\|_e\?sbat\|z_.*\)$$/\#define ZO_\2 0x\1/p' + +quiet_cmd_zoffset = ZOFFSET $@ + cmd_zoffset = $(NM) $< | sed -n $(sed-zoffset) > $@ + +targets += zoffset.h +$(obj)/zoffset.h: $(obj)/compressed/vmlinux FORCE + $(call if_changed,zoffset) + + +AFLAGS_header.o += -I$(objtree)/$(obj) +$(obj)/header.o: $(obj)/zoffset.h + +LDFLAGS_setup.elf := -m elf_i386 -z noexecstack -T +$(obj)/setup.elf: $(src)/setup.ld $(SETUP_OBJS) FORCE + $(call if_changed,ld) + +OBJCOPYFLAGS_setup.bin := -O binary +$(obj)/setup.bin: $(obj)/setup.elf FORCE + $(call if_changed,objcopy) + +$(obj)/compressed/vmlinux: FORCE + $(Q)$(MAKE) $(build)=$(obj)/compressed $@ + +# Set this if you want to pass append arguments to the +# bzdisk/fdimage/hdimage/isoimage kernel +FDARGS = +# Set this if you want one or more initrds included in the image +FDINITRD = + +imgdeps = $(obj)/bzImage $(obj)/mtools.conf $(src)/genimage.sh + +$(obj)/mtools.conf: $(src)/mtools.conf.in + sed -e 's|@OBJ@|$(obj)|g' < $< > $@ + +targets += mtools.conf + +# genimage.sh requires bash, but it also has a bunch of other +# external dependencies. +quiet_cmd_genimage = GENIMAGE $3 + cmd_genimage = $(BASH) $(src)/genimage.sh $2 $3 $(obj)/bzImage \ + $(obj)/mtools.conf '$(FDARGS)' $(FDINITRD) + +PHONY += bzdisk fdimage fdimage144 fdimage288 hdimage isoimage + +# This requires write access to /dev/fd0 +# All images require syslinux to be installed; hdimage also requires +# EDK2/OVMF if the kernel is compiled with the EFI stub. +bzdisk: $(imgdeps) + $(call cmd,genimage,bzdisk,/dev/fd0) + +fdimage fdimage144: $(imgdeps) + $(call cmd,genimage,fdimage144,$(obj)/fdimage) + @$(kecho) 'Kernel: $(obj)/fdimage is ready' + +fdimage288: $(imgdeps) + $(call cmd,genimage,fdimage288,$(obj)/fdimage) + @$(kecho) 'Kernel: $(obj)/fdimage is ready' + +hdimage: $(imgdeps) + $(call cmd,genimage,hdimage,$(obj)/hdimage) + @$(kecho) 'Kernel: $(obj)/hdimage is ready' + +isoimage: $(imgdeps) + $(call cmd,genimage,isoimage,$(obj)/image.iso) + @$(kecho) 'Kernel: $(obj)/image.iso is ready' diff --git a/arch/x86/boot/a20.c b/arch/x86/boot/a20.c new file mode 100644 index 000000000..bda042933 --- /dev/null +++ b/arch/x86/boot/a20.c @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007-2008 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Enable A20 gate (return -1 on failure) + */ + +#include "boot.h" + +#define MAX_8042_LOOPS 100000 +#define MAX_8042_FF 32 + +static int empty_8042(void) +{ + u8 status; + int loops = MAX_8042_LOOPS; + int ffs = MAX_8042_FF; + + while (loops--) { + io_delay(); + + status = inb(0x64); + if (status == 0xff) { + /* FF is a plausible, but very unlikely status */ + if (!--ffs) + return -1; /* Assume no KBC present */ + } + if (status & 1) { + /* Read and discard input data */ + io_delay(); + (void)inb(0x60); + } else if (!(status & 2)) { + /* Buffers empty, finished! */ + return 0; + } + } + + return -1; +} + +/* Returns nonzero if the A20 line is enabled. The memory address + used as a test is the int $0x80 vector, which should be safe. */ + +#define A20_TEST_ADDR (4*0x80) +#define A20_TEST_SHORT 32 +#define A20_TEST_LONG 2097152 /* 2^21 */ + +static int a20_test(int loops) +{ + int ok = 0; + int saved, ctr; + + set_fs(0x0000); + set_gs(0xffff); + + saved = ctr = rdfs32(A20_TEST_ADDR); + + while (loops--) { + wrfs32(++ctr, A20_TEST_ADDR); + io_delay(); /* Serialize and make delay constant */ + ok = rdgs32(A20_TEST_ADDR+0x10) ^ ctr; + if (ok) + break; + } + + wrfs32(saved, A20_TEST_ADDR); + return ok; +} + +/* Quick test to see if A20 is already enabled */ +static int a20_test_short(void) +{ + return a20_test(A20_TEST_SHORT); +} + +/* Longer test that actually waits for A20 to come on line; this + is useful when dealing with the KBC or other slow external circuitry. */ +static int a20_test_long(void) +{ + return a20_test(A20_TEST_LONG); +} + +static void enable_a20_bios(void) +{ + struct biosregs ireg; + + initregs(&ireg); + ireg.ax = 0x2401; + intcall(0x15, &ireg, NULL); +} + +static void enable_a20_kbc(void) +{ + empty_8042(); + + outb(0xd1, 0x64); /* Command write */ + empty_8042(); + + outb(0xdf, 0x60); /* A20 on */ + empty_8042(); + + outb(0xff, 0x64); /* Null command, but UHCI wants it */ + empty_8042(); +} + +static void enable_a20_fast(void) +{ + u8 port_a; + + port_a = inb(0x92); /* Configuration port A */ + port_a |= 0x02; /* Enable A20 */ + port_a &= ~0x01; /* Do not reset machine */ + outb(port_a, 0x92); +} + +/* + * Actual routine to enable A20; return 0 on ok, -1 on failure + */ + +#define A20_ENABLE_LOOPS 255 /* Number of times to try */ + +int enable_a20(void) +{ + int loops = A20_ENABLE_LOOPS; + int kbc_err; + + while (loops--) { + /* First, check to see if A20 is already enabled + (legacy free, etc.) */ + if (a20_test_short()) + return 0; + + /* Next, try the BIOS (INT 0x15, AX=0x2401) */ + enable_a20_bios(); + if (a20_test_short()) + return 0; + + /* Try enabling A20 through the keyboard controller */ + kbc_err = empty_8042(); + + if (a20_test_short()) + return 0; /* BIOS worked, but with delayed reaction */ + + if (!kbc_err) { + enable_a20_kbc(); + if (a20_test_long()) + return 0; + } + + /* Finally, try enabling the "fast A20 gate" */ + enable_a20_fast(); + if (a20_test_long()) + return 0; + } + + return -1; +} diff --git a/arch/x86/boot/apm.c b/arch/x86/boot/apm.c new file mode 100644 index 000000000..bda15f967 --- /dev/null +++ b/arch/x86/boot/apm.c @@ -0,0 +1,73 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * Original APM BIOS checking by Stephen Rothwell, May 1994 + * (sfr@canb.auug.org.au) + * + * ----------------------------------------------------------------------- */ + +/* + * Get APM BIOS information + */ + +#include "boot.h" + +int query_apm_bios(void) +{ + struct biosregs ireg, oreg; + + /* APM BIOS installation check */ + initregs(&ireg); + ireg.ah = 0x53; + intcall(0x15, &ireg, &oreg); + + if (oreg.flags & X86_EFLAGS_CF) + return -1; /* No APM BIOS */ + + if (oreg.bx != 0x504d) /* "PM" signature */ + return -1; + + if (!(oreg.cx & 0x02)) /* 32 bits supported? */ + return -1; + + /* Disconnect first, just in case */ + ireg.al = 0x04; + intcall(0x15, &ireg, NULL); + + /* 32-bit connect */ + ireg.al = 0x03; + intcall(0x15, &ireg, &oreg); + + boot_params.apm_bios_info.cseg = oreg.ax; + boot_params.apm_bios_info.offset = oreg.ebx; + boot_params.apm_bios_info.cseg_16 = oreg.cx; + boot_params.apm_bios_info.dseg = oreg.dx; + boot_params.apm_bios_info.cseg_len = oreg.si; + boot_params.apm_bios_info.cseg_16_len = oreg.hsi; + boot_params.apm_bios_info.dseg_len = oreg.di; + + if (oreg.flags & X86_EFLAGS_CF) + return -1; + + /* Redo the installation check as the 32-bit connect; + some BIOSes return different flags this way... */ + + ireg.al = 0x00; + intcall(0x15, &ireg, &oreg); + + if ((oreg.eflags & X86_EFLAGS_CF) || oreg.bx != 0x504d) { + /* Failure with 32-bit connect, try to disconnect and ignore */ + ireg.al = 0x04; + intcall(0x15, &ireg, NULL); + return -1; + } + + boot_params.apm_bios_info.version = oreg.ax; + boot_params.apm_bios_info.flags = oreg.cx; + return 0; +} + diff --git a/arch/x86/boot/bioscall.S b/arch/x86/boot/bioscall.S new file mode 100644 index 000000000..cf4a61557 --- /dev/null +++ b/arch/x86/boot/bioscall.S @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* ----------------------------------------------------------------------- + * + * Copyright 2009-2014 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * "Glove box" for BIOS calls. Avoids the constant problems with BIOSes + * touching registers they shouldn't be. + */ + + .code16 + .section ".inittext","ax" + .globl intcall + .type intcall, @function +intcall: + /* Self-modify the INT instruction. Ugly, but works. */ + cmpb %al, 3f + je 1f + movb %al, 3f + jmp 1f /* Synchronize pipeline */ +1: + /* Save state */ + pushfl + pushw %fs + pushw %gs + pushal + + /* Copy input state to stack frame */ + subw $44, %sp + movw %dx, %si + movw %sp, %di + movw $11, %cx + rep movsl + + /* Pop full state from the stack */ + popal + popw %gs + popw %fs + popw %es + popw %ds + popfl + + /* Actual INT */ + .byte 0xcd /* INT opcode */ +3: .byte 0 + + /* Push full state to the stack */ + pushfl + pushw %ds + pushw %es + pushw %fs + pushw %gs + pushal + + /* Re-establish C environment invariants */ + cld + movzwl %sp, %esp + movw %cs, %ax + movw %ax, %ds + movw %ax, %es + + /* Copy output state from stack frame */ + movw 68(%esp), %di /* Original %cx == 3rd argument */ + andw %di, %di + jz 4f + movw %sp, %si + movw $11, %cx + rep movsl +4: addw $44, %sp + + /* Restore state and return */ + popal + popw %gs + popw %fs + popfl + retl + .size intcall, .-intcall diff --git a/arch/x86/boot/bitops.h b/arch/x86/boot/bitops.h new file mode 100644 index 000000000..79e159715 --- /dev/null +++ b/arch/x86/boot/bitops.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Very simple bitops for the boot code. + */ + +#ifndef BOOT_BITOPS_H +#define BOOT_BITOPS_H +#define _LINUX_BITOPS_H /* Inhibit inclusion of <linux/bitops.h> */ + +#include <linux/types.h> +#include <asm/asm.h> + +static inline bool constant_test_bit(int nr, const void *addr) +{ + const u32 *p = addr; + return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0; +} +static inline bool variable_test_bit(int nr, const void *addr) +{ + bool v; + const u32 *p = addr; + + asm("btl %2,%1" : "=@ccc" (v) : "m" (*p), "Ir" (nr)); + return v; +} + +#define test_bit(nr,addr) \ +(__builtin_constant_p(nr) ? \ + constant_test_bit((nr),(addr)) : \ + variable_test_bit((nr),(addr))) + +static inline void set_bit(int nr, void *addr) +{ + asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr)); +} + +#endif /* BOOT_BITOPS_H */ diff --git a/arch/x86/boot/boot.h b/arch/x86/boot/boot.h new file mode 100644 index 000000000..8e3eab34d --- /dev/null +++ b/arch/x86/boot/boot.h @@ -0,0 +1,330 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Header file for the real-mode kernel code + */ + +#ifndef BOOT_BOOT_H +#define BOOT_BOOT_H + +#define STACK_SIZE 1024 /* Minimum number of bytes for stack */ + +#ifndef __ASSEMBLER__ + +#include <linux/stdarg.h> +#include <linux/types.h> +#include <linux/edd.h> +#include <asm/setup.h> +#include <asm/asm.h> +#include "bitops.h" +#include "ctype.h" +#include "cpuflags.h" +#include "io.h" + +/* Useful macros */ +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x))) + +extern struct setup_header hdr; +extern struct boot_params boot_params; + +#define cpu_relax() asm volatile("pause") + +static inline void io_delay(void) +{ + const u16 DELAY_PORT = 0x80; + outb(0, DELAY_PORT); +} + +/* These functions are used to reference data in other segments. */ + +static inline u16 ds(void) +{ + u16 seg; + asm("movw %%ds,%0" : "=rm" (seg)); + return seg; +} + +static inline void set_fs(u16 seg) +{ + asm volatile("movw %0,%%fs" : : "rm" (seg)); +} +static inline u16 fs(void) +{ + u16 seg; + asm volatile("movw %%fs,%0" : "=rm" (seg)); + return seg; +} + +static inline void set_gs(u16 seg) +{ + asm volatile("movw %0,%%gs" : : "rm" (seg)); +} +static inline u16 gs(void) +{ + u16 seg; + asm volatile("movw %%gs,%0" : "=rm" (seg)); + return seg; +} + +typedef unsigned int addr_t; + +static inline u8 rdfs8(addr_t addr) +{ + u8 *ptr = (u8 *)absolute_pointer(addr); + u8 v; + asm volatile("movb %%fs:%1,%0" : "=q" (v) : "m" (*ptr)); + return v; +} +static inline u16 rdfs16(addr_t addr) +{ + u16 *ptr = (u16 *)absolute_pointer(addr); + u16 v; + asm volatile("movw %%fs:%1,%0" : "=r" (v) : "m" (*ptr)); + return v; +} +static inline u32 rdfs32(addr_t addr) +{ + u32 *ptr = (u32 *)absolute_pointer(addr); + u32 v; + asm volatile("movl %%fs:%1,%0" : "=r" (v) : "m" (*ptr)); + return v; +} + +static inline void wrfs8(u8 v, addr_t addr) +{ + u8 *ptr = (u8 *)absolute_pointer(addr); + asm volatile("movb %1,%%fs:%0" : "+m" (*ptr) : "qi" (v)); +} +static inline void wrfs16(u16 v, addr_t addr) +{ + u16 *ptr = (u16 *)absolute_pointer(addr); + asm volatile("movw %1,%%fs:%0" : "+m" (*ptr) : "ri" (v)); +} +static inline void wrfs32(u32 v, addr_t addr) +{ + u32 *ptr = (u32 *)absolute_pointer(addr); + asm volatile("movl %1,%%fs:%0" : "+m" (*ptr) : "ri" (v)); +} + +static inline u8 rdgs8(addr_t addr) +{ + u8 *ptr = (u8 *)absolute_pointer(addr); + u8 v; + asm volatile("movb %%gs:%1,%0" : "=q" (v) : "m" (*ptr)); + return v; +} +static inline u16 rdgs16(addr_t addr) +{ + u16 *ptr = (u16 *)absolute_pointer(addr); + u16 v; + asm volatile("movw %%gs:%1,%0" : "=r" (v) : "m" (*ptr)); + return v; +} +static inline u32 rdgs32(addr_t addr) +{ + u32 *ptr = (u32 *)absolute_pointer(addr); + u32 v; + asm volatile("movl %%gs:%1,%0" : "=r" (v) : "m" (*ptr)); + return v; +} + +static inline void wrgs8(u8 v, addr_t addr) +{ + u8 *ptr = (u8 *)absolute_pointer(addr); + asm volatile("movb %1,%%gs:%0" : "+m" (*ptr) : "qi" (v)); +} +static inline void wrgs16(u16 v, addr_t addr) +{ + u16 *ptr = (u16 *)absolute_pointer(addr); + asm volatile("movw %1,%%gs:%0" : "+m" (*ptr) : "ri" (v)); +} +static inline void wrgs32(u32 v, addr_t addr) +{ + u32 *ptr = (u32 *)absolute_pointer(addr); + asm volatile("movl %1,%%gs:%0" : "+m" (*ptr) : "ri" (v)); +} + +/* Note: these only return true/false, not a signed return value! */ +static inline bool memcmp_fs(const void *s1, addr_t s2, size_t len) +{ + bool diff; + asm volatile("fs repe cmpsb" + : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len)); + return diff; +} +static inline bool memcmp_gs(const void *s1, addr_t s2, size_t len) +{ + bool diff; + asm volatile("gs repe cmpsb" + : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len)); + return diff; +} + +/* Heap -- available for dynamic lists. */ +extern char _end[]; +extern char *HEAP; +extern char *heap_end; +#define RESET_HEAP() ((void *)( HEAP = _end )) +static inline char *__get_heap(size_t s, size_t a, size_t n) +{ + char *tmp; + + HEAP = (char *)(((size_t)HEAP+(a-1)) & ~(a-1)); + tmp = HEAP; + HEAP += s*n; + return tmp; +} +#define GET_HEAP(type, n) \ + ((type *)__get_heap(sizeof(type),__alignof__(type),(n))) + +static inline bool heap_free(size_t n) +{ + return (int)(heap_end-HEAP) >= (int)n; +} + +/* copy.S */ + +void copy_to_fs(addr_t dst, void *src, size_t len); +void *copy_from_fs(void *dst, addr_t src, size_t len); + +/* a20.c */ +int enable_a20(void); + +/* apm.c */ +int query_apm_bios(void); + +/* bioscall.c */ +struct biosregs { + union { + struct { + u32 edi; + u32 esi; + u32 ebp; + u32 _esp; + u32 ebx; + u32 edx; + u32 ecx; + u32 eax; + u32 _fsgs; + u32 _dses; + u32 eflags; + }; + struct { + u16 di, hdi; + u16 si, hsi; + u16 bp, hbp; + u16 _sp, _hsp; + u16 bx, hbx; + u16 dx, hdx; + u16 cx, hcx; + u16 ax, hax; + u16 gs, fs; + u16 es, ds; + u16 flags, hflags; + }; + struct { + u8 dil, dih, edi2, edi3; + u8 sil, sih, esi2, esi3; + u8 bpl, bph, ebp2, ebp3; + u8 _spl, _sph, _esp2, _esp3; + u8 bl, bh, ebx2, ebx3; + u8 dl, dh, edx2, edx3; + u8 cl, ch, ecx2, ecx3; + u8 al, ah, eax2, eax3; + }; + }; +}; +void intcall(u8 int_no, const struct biosregs *ireg, struct biosregs *oreg); + +/* cmdline.c */ +int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize); +int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option); +static inline int cmdline_find_option(const char *option, char *buffer, int bufsize) +{ + unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; + + if (cmd_line_ptr >= 0x100000) + return -1; /* inaccessible */ + + return __cmdline_find_option(cmd_line_ptr, option, buffer, bufsize); +} + +static inline int cmdline_find_option_bool(const char *option) +{ + unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr; + + if (cmd_line_ptr >= 0x100000) + return -1; /* inaccessible */ + + return __cmdline_find_option_bool(cmd_line_ptr, option); +} + +/* cpu.c, cpucheck.c */ +int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr); +int check_knl_erratum(void); +int validate_cpu(void); + +/* early_serial_console.c */ +extern int early_serial_base; +void console_init(void); + +/* edd.c */ +void query_edd(void); + +/* header.S */ +void __attribute__((noreturn)) die(void); + +/* memory.c */ +void detect_memory(void); + +/* pm.c */ +void __attribute__((noreturn)) go_to_protected_mode(void); + +/* pmjump.S */ +void __attribute__((noreturn)) + protected_mode_jump(u32 entrypoint, u32 bootparams); + +/* printf.c */ +int sprintf(char *buf, const char *fmt, ...); +int vsprintf(char *buf, const char *fmt, va_list args); +int printf(const char *fmt, ...); + +/* regs.c */ +void initregs(struct biosregs *regs); + +/* string.c */ +int strcmp(const char *str1, const char *str2); +int strncmp(const char *cs, const char *ct, size_t count); +size_t strnlen(const char *s, size_t maxlen); +unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base); +size_t strlen(const char *s); +char *strchr(const char *s, int c); + +/* tty.c */ +void puts(const char *); +void putchar(int); +int getchar(void); +void kbd_flush(void); +int getchar_timeout(void); + +/* video.c */ +void set_video(void); + +/* video-mode.c */ +int set_mode(u16 mode); +int mode_defined(u16 mode); +void probe_cards(int unsafe); + +/* video-vesa.c */ +void vesa_store_edid(void); + +#endif /* __ASSEMBLER__ */ + +#endif /* BOOT_BOOT_H */ diff --git a/arch/x86/boot/cmdline.c b/arch/x86/boot/cmdline.c new file mode 100644 index 000000000..21d56ae83 --- /dev/null +++ b/arch/x86/boot/cmdline.c @@ -0,0 +1,156 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Simple command-line parser for early boot. + */ + +#include "boot.h" + +static inline int myisspace(u8 c) +{ + return c <= ' '; /* Close enough approximation */ +} + +/* + * Find a non-boolean option, that is, "option=argument". In accordance + * with standard Linux practice, if this option is repeated, this returns + * the last instance on the command line. + * + * Returns the length of the argument (regardless of if it was + * truncated to fit in the buffer), or -1 on not found. + */ +int __cmdline_find_option(unsigned long cmdline_ptr, const char *option, char *buffer, int bufsize) +{ + addr_t cptr; + char c; + int len = -1; + const char *opptr = NULL; + char *bufptr = buffer; + enum { + st_wordstart, /* Start of word/after whitespace */ + st_wordcmp, /* Comparing this word */ + st_wordskip, /* Miscompare, skip */ + st_bufcpy /* Copying this to buffer */ + } state = st_wordstart; + + if (!cmdline_ptr) + return -1; /* No command line */ + + cptr = cmdline_ptr & 0xf; + set_fs(cmdline_ptr >> 4); + + while (cptr < 0x10000 && (c = rdfs8(cptr++))) { + switch (state) { + case st_wordstart: + if (myisspace(c)) + break; + + /* else */ + state = st_wordcmp; + opptr = option; + fallthrough; + + case st_wordcmp: + if (c == '=' && !*opptr) { + len = 0; + bufptr = buffer; + state = st_bufcpy; + } else if (myisspace(c)) { + state = st_wordstart; + } else if (c != *opptr++) { + state = st_wordskip; + } + break; + + case st_wordskip: + if (myisspace(c)) + state = st_wordstart; + break; + + case st_bufcpy: + if (myisspace(c)) { + state = st_wordstart; + } else { + if (len < bufsize-1) + *bufptr++ = c; + len++; + } + break; + } + } + + if (bufsize) + *bufptr = '\0'; + + return len; +} + +/* + * Find a boolean option (like quiet,noapic,nosmp....) + * + * Returns the position of that option (starts counting with 1) + * or 0 on not found + */ +int __cmdline_find_option_bool(unsigned long cmdline_ptr, const char *option) +{ + addr_t cptr; + char c; + int pos = 0, wstart = 0; + const char *opptr = NULL; + enum { + st_wordstart, /* Start of word/after whitespace */ + st_wordcmp, /* Comparing this word */ + st_wordskip, /* Miscompare, skip */ + } state = st_wordstart; + + if (!cmdline_ptr) + return -1; /* No command line */ + + cptr = cmdline_ptr & 0xf; + set_fs(cmdline_ptr >> 4); + + while (cptr < 0x10000) { + c = rdfs8(cptr++); + pos++; + + switch (state) { + case st_wordstart: + if (!c) + return 0; + else if (myisspace(c)) + break; + + state = st_wordcmp; + opptr = option; + wstart = pos; + fallthrough; + + case st_wordcmp: + if (!*opptr) + if (!c || myisspace(c)) + return wstart; + else + state = st_wordskip; + else if (!c) + return 0; + else if (c != *opptr++) + state = st_wordskip; + break; + + case st_wordskip: + if (!c) + return 0; + else if (myisspace(c)) + state = st_wordstart; + break; + } + } + + return 0; /* Buffer overrun */ +} diff --git a/arch/x86/boot/compressed/.gitignore b/arch/x86/boot/compressed/.gitignore new file mode 100644 index 000000000..25805199a --- /dev/null +++ b/arch/x86/boot/compressed/.gitignore @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +relocs +vmlinux.bin.all +vmlinux.relocs +vmlinux.lds +mkpiggy +piggy.S diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile new file mode 100644 index 000000000..06934f969 --- /dev/null +++ b/arch/x86/boot/compressed/Makefile @@ -0,0 +1,163 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# linux/arch/x86/boot/compressed/Makefile +# +# create a compressed vmlinux image from the original vmlinux +# +# vmlinuz is: +# decompression code (*.o) +# asm globals (piggy.S), including: +# vmlinux.bin.(gz|bz2|lzma|...) +# +# vmlinux.bin is: +# vmlinux stripped of debugging and comments +# vmlinux.bin.all is: +# vmlinux.bin + vmlinux.relocs +# vmlinux.bin.(gz|bz2|lzma|...) is: +# (see scripts/Makefile.lib size_append) +# compressed vmlinux.bin.all + u32 size of vmlinux.bin.all + +targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ + vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 vmlinux.bin.zst + +# CLANG_FLAGS must come before any cc-disable-warning or cc-option calls in +# case of cross compiling, as it has the '--target=' flag, which is needed to +# avoid errors with '-march=i386', and future flags may depend on the target to +# be valid. +KBUILD_CFLAGS := -m$(BITS) -O2 $(CLANG_FLAGS) +KBUILD_CFLAGS += $(CC_FLAGS_DIALECT) +KBUILD_CFLAGS += -fno-strict-aliasing -fPIE +KBUILD_CFLAGS += -fno-jump-tables +KBUILD_CFLAGS += -Wundef +KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING +cflags-$(CONFIG_X86_32) := -march=i386 +cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone +KBUILD_CFLAGS += $(cflags-y) +KBUILD_CFLAGS += -mno-mmx -mno-sse +KBUILD_CFLAGS += -ffreestanding -fshort-wchar +KBUILD_CFLAGS += -fno-stack-protector +KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) +KBUILD_CFLAGS += -Wno-pointer-sign +KBUILD_CFLAGS += -fno-asynchronous-unwind-tables +KBUILD_CFLAGS += -D__DISABLE_EXPORTS +# Disable relocation relaxation in case the link is not PIE. +KBUILD_CFLAGS += $(call cc-option,-Wa$(comma)-mrelax-relocations=no) +KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h + +# sev-decode-insn.c indirectly includes inat-table.c which is generated during +# compilation and stored in $(objtree). Add the directory to the includes so +# that the compiler finds it even with out-of-tree builds (make O=/some/path). +CFLAGS_sev-handle-vc.o += -I$(objtree)/arch/x86/lib/ + +KBUILD_AFLAGS := $(KBUILD_CFLAGS) -D__ASSEMBLY__ + +KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) +KBUILD_LDFLAGS += $(call ld-option,--no-ld-generated-unwind-info) +# Compressed kernel should be built as PIE since it may be loaded at any +# address by the bootloader. +LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker) +ifdef CONFIG_LD_ORPHAN_WARN +LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL) +endif +LDFLAGS_vmlinux += -z noexecstack +ifeq ($(CONFIG_LD_IS_BFD),y) +LDFLAGS_vmlinux += $(call ld-option,--no-warn-rwx-segments) +endif +ifeq ($(CONFIG_EFI_STUB),y) +# ensure that the static EFI stub library will be pulled in, even if it is +# never referenced explicitly from the startup code +LDFLAGS_vmlinux += -u efi_pe_entry +endif +LDFLAGS_vmlinux += -T + +hostprogs := mkpiggy +HOST_EXTRACFLAGS += -I$(srctree)/tools/include + +sed-voffset := -e 's/^\([0-9a-fA-F]*\) [ABbCDGRSTtVW] \(_text\|__start_rodata\|_sinittext\|__inittext_end\|__bss_start\|_end\)$$/\#define VO_\2 _AC(0x\1,UL)/p' + +quiet_cmd_voffset = VOFFSET $@ + cmd_voffset = $(NM) $< | sed -n $(sed-voffset) > $@ + +targets += ../voffset.h + +$(obj)/../voffset.h: vmlinux FORCE + $(call if_changed,voffset) + +$(obj)/misc.o: $(obj)/../voffset.h + +vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o \ + $(obj)/misc.o $(obj)/string.o $(obj)/cmdline.o $(obj)/error.o \ + $(obj)/piggy.o $(obj)/cpuflags.o + +vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o +vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o +ifdef CONFIG_X86_64 + vmlinux-objs-y += $(obj)/ident_map_64.o + vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o + vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/mem_encrypt.o + vmlinux-objs-y += $(obj)/pgtable_64.o + vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev.o $(obj)/sev-handle-vc.o +endif + +vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o +vmlinux-objs-$(CONFIG_INTEL_TDX_GUEST) += $(obj)/tdx.o $(obj)/tdcall.o $(obj)/tdx-shared.o +vmlinux-objs-$(CONFIG_UNACCEPTED_MEMORY) += $(obj)/mem.o + +vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi.o +vmlinux-libs-$(CONFIG_EFI_STUB) += $(objtree)/drivers/firmware/efi/libstub/lib.a +vmlinux-libs-$(CONFIG_X86_64) += $(objtree)/arch/x86/boot/startup/lib.a +vmlinux-objs-$(CONFIG_EFI_SBAT) += $(obj)/sbat.o + +ifdef CONFIG_EFI_SBAT +$(obj)/sbat.o: $(CONFIG_EFI_SBAT_FILE) +AFLAGS_sbat.o += -I $(srctree) +endif + +$(obj)/vmlinux: $(vmlinux-objs-y) $(vmlinux-libs-y) FORCE + $(call if_changed,ld) + +OBJCOPYFLAGS_vmlinux.bin := -R .comment -S +$(obj)/vmlinux.bin: vmlinux FORCE + $(call if_changed,objcopy) + +targets += $(patsubst $(obj)/%,%,$(vmlinux-objs-y)) vmlinux.bin.all vmlinux.relocs + +CMD_RELOCS = arch/x86/tools/relocs +quiet_cmd_relocs = RELOCS $@ + cmd_relocs = $(CMD_RELOCS) $< > $@;$(CMD_RELOCS) --abs-relocs $< + +$(obj)/vmlinux.relocs: vmlinux.unstripped FORCE + $(call if_changed,relocs) + +vmlinux.bin.all-y := $(obj)/vmlinux.bin +vmlinux.bin.all-$(CONFIG_X86_NEED_RELOCS) += $(obj)/vmlinux.relocs + +$(obj)/vmlinux.bin.gz: $(vmlinux.bin.all-y) FORCE + $(call if_changed,gzip) +$(obj)/vmlinux.bin.bz2: $(vmlinux.bin.all-y) FORCE + $(call if_changed,bzip2_with_size) +$(obj)/vmlinux.bin.lzma: $(vmlinux.bin.all-y) FORCE + $(call if_changed,lzma_with_size) +$(obj)/vmlinux.bin.xz: $(vmlinux.bin.all-y) FORCE + $(call if_changed,xzkern_with_size) +$(obj)/vmlinux.bin.lzo: $(vmlinux.bin.all-y) FORCE + $(call if_changed,lzo_with_size) +$(obj)/vmlinux.bin.lz4: $(vmlinux.bin.all-y) FORCE + $(call if_changed,lz4_with_size) +$(obj)/vmlinux.bin.zst: $(vmlinux.bin.all-y) FORCE + $(call if_changed,zstd22_with_size) + +suffix-$(CONFIG_KERNEL_GZIP) := gz +suffix-$(CONFIG_KERNEL_BZIP2) := bz2 +suffix-$(CONFIG_KERNEL_LZMA) := lzma +suffix-$(CONFIG_KERNEL_XZ) := xz +suffix-$(CONFIG_KERNEL_LZO) := lzo +suffix-$(CONFIG_KERNEL_LZ4) := lz4 +suffix-$(CONFIG_KERNEL_ZSTD) := zst + +quiet_cmd_mkpiggy = MKPIGGY $@ + cmd_mkpiggy = $(obj)/mkpiggy $< > $@ + +targets += piggy.S +$(obj)/piggy.S: $(obj)/vmlinux.bin.$(suffix-y) $(obj)/mkpiggy FORCE + $(call if_changed,mkpiggy) diff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c new file mode 100644 index 000000000..aed27604c --- /dev/null +++ b/arch/x86/boot/compressed/acpi.c @@ -0,0 +1,322 @@ +// SPDX-License-Identifier: GPL-2.0 +#define BOOT_CTYPE_H +#include "misc.h" +#include "error.h" +#include "../string.h" +#include "efi.h" + +#include <asm/bootparam.h> + +#include <linux/numa.h> + +/* + * Longest parameter of 'acpi=' is 'copy_dsdt', plus an extra '\0' + * for termination. + */ +#define MAX_ACPI_ARG_LENGTH 10 + +/* + * Immovable memory regions representation. Max amount of memory regions is + * MAX_NUMNODES*2. + */ +struct mem_vector immovable_mem[MAX_NUMNODES*2]; + +static acpi_physical_address +__efi_get_rsdp_addr(unsigned long cfg_tbl_pa, unsigned int cfg_tbl_len) +{ +#ifdef CONFIG_EFI + unsigned long rsdp_addr; + int ret; + + /* + * Search EFI system tables for RSDP. Preferred is ACPI_20_TABLE_GUID to + * ACPI_TABLE_GUID because it has more features. + */ + rsdp_addr = efi_find_vendor_table(boot_params_ptr, cfg_tbl_pa, cfg_tbl_len, + ACPI_20_TABLE_GUID); + if (rsdp_addr) + return (acpi_physical_address)rsdp_addr; + + /* No ACPI_20_TABLE_GUID found, fallback to ACPI_TABLE_GUID. */ + rsdp_addr = efi_find_vendor_table(boot_params_ptr, cfg_tbl_pa, cfg_tbl_len, + ACPI_TABLE_GUID); + if (rsdp_addr) + return (acpi_physical_address)rsdp_addr; + + debug_putstr("Error getting RSDP address.\n"); +#endif + return 0; +} + +static acpi_physical_address efi_get_rsdp_addr(void) +{ +#ifdef CONFIG_EFI + unsigned long cfg_tbl_pa = 0; + unsigned int cfg_tbl_len; + unsigned long systab_pa; + unsigned int nr_tables; + enum efi_type et; + int ret; + + et = efi_get_type(boot_params_ptr); + if (et == EFI_TYPE_NONE) + return 0; + + systab_pa = efi_get_system_table(boot_params_ptr); + if (!systab_pa) + error("EFI support advertised, but unable to locate system table."); + + ret = efi_get_conf_table(boot_params_ptr, &cfg_tbl_pa, &cfg_tbl_len); + if (ret || !cfg_tbl_pa) + error("EFI config table not found."); + + return __efi_get_rsdp_addr(cfg_tbl_pa, cfg_tbl_len); +#else + return 0; +#endif +} + +static u8 compute_checksum(u8 *buffer, u32 length) +{ + u8 *end = buffer + length; + u8 sum = 0; + + while (buffer < end) + sum += *(buffer++); + + return sum; +} + +/* Search a block of memory for the RSDP signature. */ +static u8 *scan_mem_for_rsdp(u8 *start, u32 length) +{ + struct acpi_table_rsdp *rsdp; + u8 *address, *end; + + end = start + length; + + /* Search from given start address for the requested length */ + for (address = start; address < end; address += ACPI_RSDP_SCAN_STEP) { + /* + * Both RSDP signature and checksum must be correct. + * Note: Sometimes there exists more than one RSDP in memory; + * the valid RSDP has a valid checksum, all others have an + * invalid checksum. + */ + rsdp = (struct acpi_table_rsdp *)address; + + /* BAD Signature */ + if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature)) + continue; + + /* Check the standard checksum */ + if (compute_checksum((u8 *)rsdp, ACPI_RSDP_CHECKSUM_LENGTH)) + continue; + + /* Check extended checksum if table version >= 2 */ + if ((rsdp->revision >= 2) && + (compute_checksum((u8 *)rsdp, ACPI_RSDP_XCHECKSUM_LENGTH))) + continue; + + /* Signature and checksum valid, we have found a real RSDP */ + return address; + } + return NULL; +} + +/* Search RSDP address in EBDA. */ +static acpi_physical_address bios_get_rsdp_addr(void) +{ + unsigned long address; + u8 *rsdp; + + /* Get the location of the Extended BIOS Data Area (EBDA) */ + address = *(u16 *)ACPI_EBDA_PTR_LOCATION; + address <<= 4; + + /* + * Search EBDA paragraphs (EBDA is required to be a minimum of + * 1K length) + */ + if (address > 0x400) { + rsdp = scan_mem_for_rsdp((u8 *)address, ACPI_EBDA_WINDOW_SIZE); + if (rsdp) + return (acpi_physical_address)(unsigned long)rsdp; + } + + /* Search upper memory: 16-byte boundaries in E0000h-FFFFFh */ + rsdp = scan_mem_for_rsdp((u8 *) ACPI_HI_RSDP_WINDOW_BASE, + ACPI_HI_RSDP_WINDOW_SIZE); + if (rsdp) + return (acpi_physical_address)(unsigned long)rsdp; + + return 0; +} + +/* Return RSDP address on success, otherwise 0. */ +acpi_physical_address get_rsdp_addr(void) +{ + acpi_physical_address pa; + + pa = boot_params_ptr->acpi_rsdp_addr; + + if (!pa) + pa = efi_get_rsdp_addr(); + + if (!pa) + pa = bios_get_rsdp_addr(); + + return pa; +} + +#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE) +/* + * Max length of 64-bit hex address string is 19, prefix "0x" + 16 hex + * digits, and '\0' for termination. + */ +#define MAX_ADDR_LEN 19 + +static unsigned long get_cmdline_acpi_rsdp(void) +{ + unsigned long addr = 0; + +#ifdef CONFIG_KEXEC_CORE + char val[MAX_ADDR_LEN] = { }; + int ret; + + ret = cmdline_find_option("acpi_rsdp", val, sizeof(val)); + if (ret < 0) + return 0; + + if (ret >= sizeof(val)) { + warn("acpi_rsdp= value too long; ignoring"); + return 0; + } + + if (boot_kstrtoul(val, 16, &addr)) + return 0; +#endif + return addr; +} + +/* Compute SRAT address from RSDP. */ +static unsigned long get_acpi_srat_table(void) +{ + unsigned long root_table, acpi_table; + struct acpi_table_header *header; + struct acpi_table_rsdp *rsdp; + u32 num_entries, size, len; + char arg[10]; + u8 *entry; + + /* + * Check whether we were given an RSDP on the command line. We don't + * stash this in boot params because the kernel itself may have + * different ideas about whether to trust a command-line parameter. + */ + rsdp = (struct acpi_table_rsdp *)get_cmdline_acpi_rsdp(); + if (!rsdp) + rsdp = (struct acpi_table_rsdp *)(long) + boot_params_ptr->acpi_rsdp_addr; + + if (!rsdp) + return 0; + + /* Get ACPI root table from RSDP.*/ + if (!(cmdline_find_option("acpi", arg, sizeof(arg)) == 4 && + !strncmp(arg, "rsdt", 4)) && + rsdp->xsdt_physical_address && + rsdp->revision > 1) { + root_table = rsdp->xsdt_physical_address; + size = ACPI_XSDT_ENTRY_SIZE; + } else { + root_table = rsdp->rsdt_physical_address; + size = ACPI_RSDT_ENTRY_SIZE; + } + + if (!root_table) + return 0; + + header = (struct acpi_table_header *)root_table; + len = header->length; + if (len < sizeof(struct acpi_table_header) + size) + return 0; + + num_entries = (len - sizeof(struct acpi_table_header)) / size; + entry = (u8 *)(root_table + sizeof(struct acpi_table_header)); + + while (num_entries--) { + if (size == ACPI_RSDT_ENTRY_SIZE) + acpi_table = *(u32 *)entry; + else + acpi_table = *(u64 *)entry; + + if (acpi_table) { + header = (struct acpi_table_header *)acpi_table; + + if (ACPI_COMPARE_NAMESEG(header->signature, ACPI_SIG_SRAT)) + return acpi_table; + } + entry += size; + } + return 0; +} + +/** + * count_immovable_mem_regions - Parse SRAT and cache the immovable + * memory regions into the immovable_mem array. + * + * Return the number of immovable memory regions on success, 0 on failure: + * + * - Too many immovable memory regions + * - ACPI off or no SRAT found + * - No immovable memory region found. + */ +int count_immovable_mem_regions(void) +{ + unsigned long table_addr, table_end, table; + struct acpi_subtable_header *sub_table; + struct acpi_table_header *table_header; + char arg[MAX_ACPI_ARG_LENGTH]; + int num = 0; + + if (cmdline_find_option("acpi", arg, sizeof(arg)) == 3 && + !strncmp(arg, "off", 3)) + return 0; + + table_addr = get_acpi_srat_table(); + if (!table_addr) + return 0; + + table_header = (struct acpi_table_header *)table_addr; + table_end = table_addr + table_header->length; + table = table_addr + sizeof(struct acpi_table_srat); + + while (table + sizeof(struct acpi_subtable_header) < table_end) { + + sub_table = (struct acpi_subtable_header *)table; + if (!sub_table->length) { + debug_putstr("Invalid zero length SRAT subtable.\n"); + return 0; + } + + if (sub_table->type == ACPI_SRAT_TYPE_MEMORY_AFFINITY) { + struct acpi_srat_mem_affinity *ma; + + ma = (struct acpi_srat_mem_affinity *)sub_table; + if (!(ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) && ma->length) { + immovable_mem[num].start = ma->base_address; + immovable_mem[num].size = ma->length; + num++; + } + + if (num >= MAX_NUMNODES*2) { + debug_putstr("Too many immovable memory regions, aborting.\n"); + return 0; + } + } + table += sub_table->length; + } + return num; +} +#endif /* CONFIG_RANDOMIZE_BASE && CONFIG_MEMORY_HOTREMOVE */ diff --git a/arch/x86/boot/compressed/cmdline.c b/arch/x86/boot/compressed/cmdline.c new file mode 100644 index 000000000..e162d7f59 --- /dev/null +++ b/arch/x86/boot/compressed/cmdline.c @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "misc.h" + +#include <asm/bootparam.h> + +static unsigned long fs; +static inline void set_fs(unsigned long seg) +{ + fs = seg << 4; /* shift it back */ +} +typedef unsigned long addr_t; +static inline char rdfs8(addr_t addr) +{ + return *((char *)(fs + addr)); +} +#include "../cmdline.c" +unsigned long get_cmd_line_ptr(void) +{ + unsigned long cmd_line_ptr = boot_params_ptr->hdr.cmd_line_ptr; + + cmd_line_ptr |= (u64)boot_params_ptr->ext_cmd_line_ptr << 32; + + return cmd_line_ptr; +} +int cmdline_find_option(const char *option, char *buffer, int bufsize) +{ + return __cmdline_find_option(get_cmd_line_ptr(), option, buffer, bufsize); +} +int cmdline_find_option_bool(const char *option) +{ + return __cmdline_find_option_bool(get_cmd_line_ptr(), option); +} diff --git a/arch/x86/boot/compressed/cpuflags.c b/arch/x86/boot/compressed/cpuflags.c new file mode 100644 index 000000000..0cc132389 --- /dev/null +++ b/arch/x86/boot/compressed/cpuflags.c @@ -0,0 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "../cpuflags.c" + +bool has_cpuflag(int flag) +{ + get_cpuflags(); + + return test_bit(flag, cpu.flags); +} diff --git a/arch/x86/boot/compressed/early_serial_console.c b/arch/x86/boot/compressed/early_serial_console.c new file mode 100644 index 000000000..70a8d1706 --- /dev/null +++ b/arch/x86/boot/compressed/early_serial_console.c @@ -0,0 +1,6 @@ +#include "misc.h" + +/* This might be accessed before .bss is cleared, so use .data instead. */ +int early_serial_base __section(".data"); + +#include "../early_serial_console.c" diff --git a/arch/x86/boot/compressed/efi.c b/arch/x86/boot/compressed/efi.c new file mode 100644 index 000000000..f2e50f975 --- /dev/null +++ b/arch/x86/boot/compressed/efi.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Helpers for early access to EFI configuration table. + * + * Originally derived from arch/x86/boot/compressed/acpi.c + */ + +#include "misc.h" + +#include <asm/bootparam.h> + +/** + * efi_get_type - Given a pointer to boot_params, determine the type of EFI environment. + * + * @bp: pointer to boot_params + * + * Return: EFI_TYPE_{32,64} for valid EFI environments, EFI_TYPE_NONE otherwise. + */ +enum efi_type efi_get_type(struct boot_params *bp) +{ + struct efi_info *ei; + enum efi_type et; + const char *sig; + + ei = &bp->efi_info; + sig = (char *)&ei->efi_loader_signature; + + if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4)) { + et = EFI_TYPE_64; + } else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4)) { + et = EFI_TYPE_32; + } else { + debug_putstr("No EFI environment detected.\n"); + et = EFI_TYPE_NONE; + } + +#ifndef CONFIG_X86_64 + /* + * Existing callers like acpi.c treat this case as an indicator to + * fall-through to non-EFI, rather than an error, so maintain that + * functionality here as well. + */ + if (ei->efi_systab_hi || ei->efi_memmap_hi) { + debug_putstr("EFI system table is located above 4GB and cannot be accessed.\n"); + et = EFI_TYPE_NONE; + } +#endif + + return et; +} + +/** + * efi_get_system_table - Given a pointer to boot_params, retrieve the physical address + * of the EFI system table. + * + * @bp: pointer to boot_params + * + * Return: EFI system table address on success. On error, return 0. + */ +unsigned long efi_get_system_table(struct boot_params *bp) +{ + unsigned long sys_tbl_pa; + struct efi_info *ei; + enum efi_type et; + + /* Get systab from boot params. */ + ei = &bp->efi_info; +#ifdef CONFIG_X86_64 + sys_tbl_pa = ei->efi_systab | ((__u64)ei->efi_systab_hi << 32); +#else + sys_tbl_pa = ei->efi_systab; +#endif + if (!sys_tbl_pa) { + debug_putstr("EFI system table not found."); + return 0; + } + + return sys_tbl_pa; +} + +/* + * EFI config table address changes to virtual address after boot, which may + * not be accessible for the kexec'd kernel. To address this, kexec provides + * the initial physical address via a struct setup_data entry, which is + * checked for here, along with some sanity checks. + */ +static struct efi_setup_data *get_kexec_setup_data(struct boot_params *bp, + enum efi_type et) +{ +#ifdef CONFIG_X86_64 + struct efi_setup_data *esd = NULL; + struct setup_data *data; + u64 pa_data; + + pa_data = bp->hdr.setup_data; + while (pa_data) { + data = (struct setup_data *)pa_data; + if (data->type == SETUP_EFI) { + esd = (struct efi_setup_data *)(pa_data + sizeof(struct setup_data)); + break; + } + + pa_data = data->next; + } + + /* + * Original ACPI code falls back to attempting normal EFI boot in these + * cases, so maintain existing behavior by indicating non-kexec + * environment to the caller, but print them for debugging. + */ + if (esd && !esd->tables) { + debug_putstr("kexec EFI environment missing valid configuration table.\n"); + return NULL; + } + + return esd; +#endif + return NULL; +} + +/** + * efi_get_conf_table - Given a pointer to boot_params, locate and return the physical + * address of EFI configuration table. + * + * @bp: pointer to boot_params + * @cfg_tbl_pa: location to store physical address of config table + * @cfg_tbl_len: location to store number of config table entries + * + * Return: 0 on success. On error, return params are left unchanged. + */ +int efi_get_conf_table(struct boot_params *bp, unsigned long *cfg_tbl_pa, + unsigned int *cfg_tbl_len) +{ + unsigned long sys_tbl_pa; + enum efi_type et; + int ret; + + if (!cfg_tbl_pa || !cfg_tbl_len) + return -EINVAL; + + sys_tbl_pa = efi_get_system_table(bp); + if (!sys_tbl_pa) + return -EINVAL; + + /* Handle EFI bitness properly */ + et = efi_get_type(bp); + if (et == EFI_TYPE_64) { + efi_system_table_64_t *stbl = (efi_system_table_64_t *)sys_tbl_pa; + struct efi_setup_data *esd; + + /* kexec provides an alternative EFI conf table, check for it. */ + esd = get_kexec_setup_data(bp, et); + + *cfg_tbl_pa = esd ? esd->tables : stbl->tables; + *cfg_tbl_len = stbl->nr_tables; + } else if (et == EFI_TYPE_32) { + efi_system_table_32_t *stbl = (efi_system_table_32_t *)sys_tbl_pa; + + *cfg_tbl_pa = stbl->tables; + *cfg_tbl_len = stbl->nr_tables; + } else { + return -EINVAL; + } + + return 0; +} + +/* Get vendor table address/guid from EFI config table at the given index */ +static int get_vendor_table(void *cfg_tbl, unsigned int idx, + unsigned long *vendor_tbl_pa, + efi_guid_t *vendor_tbl_guid, + enum efi_type et) +{ + if (et == EFI_TYPE_64) { + efi_config_table_64_t *tbl_entry = (efi_config_table_64_t *)cfg_tbl + idx; + + if (!IS_ENABLED(CONFIG_X86_64) && tbl_entry->table >> 32) { + debug_putstr("Error: EFI config table entry located above 4GB.\n"); + return -EINVAL; + } + + *vendor_tbl_pa = tbl_entry->table; + *vendor_tbl_guid = tbl_entry->guid; + + } else if (et == EFI_TYPE_32) { + efi_config_table_32_t *tbl_entry = (efi_config_table_32_t *)cfg_tbl + idx; + + *vendor_tbl_pa = tbl_entry->table; + *vendor_tbl_guid = tbl_entry->guid; + } else { + return -EINVAL; + } + + return 0; +} + +/** + * efi_find_vendor_table - Given EFI config table, search it for the physical + * address of the vendor table associated with GUID. + * + * @bp: pointer to boot_params + * @cfg_tbl_pa: pointer to EFI configuration table + * @cfg_tbl_len: number of entries in EFI configuration table + * @guid: GUID of vendor table + * + * Return: vendor table address on success. On error, return 0. + */ +unsigned long efi_find_vendor_table(struct boot_params *bp, + unsigned long cfg_tbl_pa, + unsigned int cfg_tbl_len, + efi_guid_t guid) +{ + enum efi_type et; + unsigned int i; + + et = efi_get_type(bp); + if (et == EFI_TYPE_NONE) + return 0; + + for (i = 0; i < cfg_tbl_len; i++) { + unsigned long vendor_tbl_pa; + efi_guid_t vendor_tbl_guid; + int ret; + + ret = get_vendor_table((void *)cfg_tbl_pa, i, + &vendor_tbl_pa, + &vendor_tbl_guid, et); + if (ret) + return 0; + + if (!efi_guidcmp(guid, vendor_tbl_guid)) + return vendor_tbl_pa; + } + + return 0; +} diff --git a/arch/x86/boot/compressed/efi.h b/arch/x86/boot/compressed/efi.h new file mode 100644 index 000000000..b22300970 --- /dev/null +++ b/arch/x86/boot/compressed/efi.h @@ -0,0 +1,127 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_COMPRESSED_EFI_H +#define BOOT_COMPRESSED_EFI_H + +#if defined(_LINUX_EFI_H) || defined(_ASM_X86_EFI_H) +#error Please do not include kernel proper namespace headers +#endif + +typedef guid_t efi_guid_t __aligned(__alignof__(u32)); + +#define EFI_GUID(a, b, c, d...) (efi_guid_t){ { \ + (a) & 0xff, ((a) >> 8) & 0xff, ((a) >> 16) & 0xff, ((a) >> 24) & 0xff, \ + (b) & 0xff, ((b) >> 8) & 0xff, \ + (c) & 0xff, ((c) >> 8) & 0xff, d } } + +#define ACPI_TABLE_GUID EFI_GUID(0xeb9d2d30, 0x2d88, 0x11d3, 0x9a, 0x16, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d) +#define ACPI_20_TABLE_GUID EFI_GUID(0x8868e871, 0xe4f1, 0x11d3, 0xbc, 0x22, 0x00, 0x80, 0xc7, 0x3c, 0x88, 0x81) +#define EFI_CC_BLOB_GUID EFI_GUID(0x067b1f5f, 0xcf26, 0x44c5, 0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42) +#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9, 0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31) + +#define EFI32_LOADER_SIGNATURE "EL32" +#define EFI64_LOADER_SIGNATURE "EL64" + +/* + * Generic EFI table header + */ +typedef struct { + u64 signature; + u32 revision; + u32 headersize; + u32 crc32; + u32 reserved; +} efi_table_hdr_t; + +#define EFI_CONVENTIONAL_MEMORY 7 +#define EFI_UNACCEPTED_MEMORY 15 + +#define EFI_MEMORY_MORE_RELIABLE \ + ((u64)0x0000000000010000ULL) /* higher reliability */ +#define EFI_MEMORY_SP ((u64)0x0000000000040000ULL) /* soft reserved */ + +#define EFI_PAGE_SHIFT 12 + +typedef struct { + u32 type; + u32 pad; + u64 phys_addr; + u64 virt_addr; + u64 num_pages; + u64 attribute; +} efi_memory_desc_t; + +#define efi_early_memdesc_ptr(map, desc_size, n) \ + (efi_memory_desc_t *)((void *)(map) + ((n) * (desc_size))) + +typedef struct { + efi_guid_t guid; + u64 table; +} efi_config_table_64_t; + +typedef struct { + efi_guid_t guid; + u32 table; +} efi_config_table_32_t; + +typedef struct { + efi_table_hdr_t hdr; + u64 fw_vendor; /* physical addr of CHAR16 vendor string */ + u32 fw_revision; + u32 __pad1; + u64 con_in_handle; + u64 con_in; + u64 con_out_handle; + u64 con_out; + u64 stderr_handle; + u64 stderr; + u64 runtime; + u64 boottime; + u32 nr_tables; + u32 __pad2; + u64 tables; +} efi_system_table_64_t; + +typedef struct { + efi_table_hdr_t hdr; + u32 fw_vendor; /* physical addr of CHAR16 vendor string */ + u32 fw_revision; + u32 con_in_handle; + u32 con_in; + u32 con_out_handle; + u32 con_out; + u32 stderr_handle; + u32 stderr; + u32 runtime; + u32 boottime; + u32 nr_tables; + u32 tables; +} efi_system_table_32_t; + +struct efi_unaccepted_memory { + u32 version; + u32 unit_size; + u64 phys_base; + u64 size; + unsigned long bitmap[]; +}; + +static inline int efi_guidcmp (efi_guid_t left, efi_guid_t right) +{ + return memcmp(&left, &right, sizeof (efi_guid_t)); +} + +#ifdef CONFIG_EFI +bool __pure __efi_soft_reserve_enabled(void); + +static inline bool __pure efi_soft_reserve_enabled(void) +{ + return IS_ENABLED(CONFIG_EFI_SOFT_RESERVE) + && __efi_soft_reserve_enabled(); +} +#else +static inline bool efi_soft_reserve_enabled(void) +{ + return false; +} +#endif /* CONFIG_EFI */ +#endif /* BOOT_COMPRESSED_EFI_H */ diff --git a/arch/x86/boot/compressed/error.c b/arch/x86/boot/compressed/error.c new file mode 100644 index 000000000..19a8251de --- /dev/null +++ b/arch/x86/boot/compressed/error.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Callers outside of misc.c need access to the error reporting routines, + * but the *_putstr() functions need to stay in misc.c because of how + * memcpy() and memmove() are defined for the compressed boot environment. + */ +#include "misc.h" +#include "error.h" + +void warn(const char *m) +{ + error_putstr("\n\n"); + error_putstr(m); + error_putstr("\n\n"); +} + +void error(char *m) +{ + warn(m); + error_putstr(" -- System halted"); + + while (1) + asm("hlt"); +} + +/* EFI libstub provides vsnprintf() */ +#ifdef CONFIG_EFI_STUB +void panic(const char *fmt, ...) +{ + static char buf[1024]; + va_list args; + int len; + + va_start(args, fmt); + len = vsnprintf(buf, sizeof(buf), fmt, args); + va_end(args); + + if (len && buf[len - 1] == '\n') + buf[len - 1] = '\0'; + + error(buf); +} +#endif diff --git a/arch/x86/boot/compressed/error.h b/arch/x86/boot/compressed/error.h new file mode 100644 index 000000000..31f9e080d --- /dev/null +++ b/arch/x86/boot/compressed/error.h @@ -0,0 +1,11 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_COMPRESSED_ERROR_H +#define BOOT_COMPRESSED_ERROR_H + +#include <linux/compiler.h> + +void warn(const char *m); +void error(char *m) __noreturn; +void panic(const char *fmt, ...) __noreturn __cold; + +#endif /* BOOT_COMPRESSED_ERROR_H */ diff --git a/arch/x86/boot/compressed/head_32.S b/arch/x86/boot/compressed/head_32.S new file mode 100644 index 000000000..1cfe9802a --- /dev/null +++ b/arch/x86/boot/compressed/head_32.S @@ -0,0 +1,188 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/boot/head.S + * + * Copyright (C) 1991, 1992, 1993 Linus Torvalds + */ + +/* + * head.S contains the 32-bit startup code. + * + * NOTE!!! Startup happens at absolute address 0x00001000, which is also where + * the page directory will exist. The startup code will be overwritten by + * the page directory. [According to comments etc elsewhere on a compressed + * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] + * + * Page 0 is deliberately kept safe, since System Management Mode code in + * laptops may need to access the BIOS data stored there. This is also + * useful for future device drivers that either access the BIOS via VM86 + * mode. + */ + +/* + * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 + */ + .text + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/segment.h> +#include <asm/page_types.h> +#include <asm/boot.h> +#include <asm/asm-offsets.h> +#include <asm/bootparam.h> + +/* + * These symbols needed to be marked as .hidden to prevent the BFD linker from + * generating R_386_32 (rather than R_386_RELATIVE) relocations for them when + * the 32-bit compressed kernel is linked as PIE. This is no longer necessary, + * but it doesn't hurt to keep them .hidden. + */ + .hidden _bss + .hidden _ebss + .hidden _end + + __HEAD +SYM_FUNC_START(startup_32) + cld + cli + +/* + * Calculate the delta between where we were compiled to run + * at and where we were actually loaded at. This can only be done + * with a short local call on x86. Nothing else will tell us what + * address we are running at. The reserved chunk of the real-mode + * data at 0x1e4 (defined as a scratch field) are used as the stack + * for this calculation. Only 4 bytes are needed. + */ + leal (BP_scratch+4)(%esi), %esp + call 1f +1: popl %edx + addl $_GLOBAL_OFFSET_TABLE_+(.-1b), %edx + + /* Load new GDT */ + leal gdt@GOTOFF(%edx), %eax + movl %eax, 2(%eax) + lgdt (%eax) + + /* Load segment registers with our descriptors */ + movl $__BOOT_DS, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %fs + movl %eax, %gs + movl %eax, %ss + +/* + * %edx contains the address we are loaded at by the boot loader (plus the + * offset to the GOT). The below code calculates %ebx to be the address where + * we should move the kernel image temporarily for safe in-place decompression + * (again, plus the offset to the GOT). + * + * %ebp is calculated to be the address that the kernel will be decompressed to. + */ + +#ifdef CONFIG_RELOCATABLE + leal startup_32@GOTOFF(%edx), %ebx + movl BP_kernel_alignment(%esi), %eax + decl %eax + addl %eax, %ebx + notl %eax + andl %eax, %ebx + cmpl $LOAD_PHYSICAL_ADDR, %ebx + jae 1f +#endif + movl $LOAD_PHYSICAL_ADDR, %ebx +1: + + movl %ebx, %ebp // Save the output address for later + /* Target address to relocate to for decompression */ + addl BP_init_size(%esi), %ebx + subl $_end@GOTOFF, %ebx + + /* Set up the stack */ + leal boot_stack_end@GOTOFF(%ebx), %esp + + /* Zero EFLAGS */ + pushl $0 + popfl + +/* + * Copy the compressed kernel to the end of our buffer + * where decompression in place becomes safe. + */ + pushl %esi + leal (_bss@GOTOFF-4)(%edx), %esi + leal (_bss@GOTOFF-4)(%ebx), %edi + movl $(_bss - startup_32), %ecx + shrl $2, %ecx + std + rep movsl + cld + popl %esi + + /* + * The GDT may get overwritten either during the copy we just did or + * during extract_kernel below. To avoid any issues, repoint the GDTR + * to the new copy of the GDT. + */ + leal gdt@GOTOFF(%ebx), %eax + movl %eax, 2(%eax) + lgdt (%eax) + +/* + * Jump to the relocated address. + */ + leal .Lrelocated@GOTOFF(%ebx), %eax + jmp *%eax +SYM_FUNC_END(startup_32) + + .text +SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) + +/* + * Clear BSS (stack is currently empty) + */ + xorl %eax, %eax + leal _bss@GOTOFF(%ebx), %edi + leal _ebss@GOTOFF(%ebx), %ecx + subl %edi, %ecx + shrl $2, %ecx + rep stosl + +/* + * Do the extraction, and jump to the new kernel.. + */ + /* push arguments for extract_kernel: */ + + pushl %ebp /* output address */ + pushl %esi /* real mode pointer */ + call extract_kernel /* returns kernel entry point in %eax */ + addl $24, %esp + +/* + * Jump to the extracted kernel. + */ + xorl %ebx, %ebx + jmp *%eax +SYM_FUNC_END(.Lrelocated) + + .data + .balign 8 +SYM_DATA_START_LOCAL(gdt) + .word gdt_end - gdt - 1 + .long 0 + .word 0 + .quad 0x0000000000000000 /* Reserved */ + .quad 0x00cf9a000000ffff /* __KERNEL_CS */ + .quad 0x00cf92000000ffff /* __KERNEL_DS */ +SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) + +/* + * Stack and heap for uncompression + */ + .bss + .balign 4 +boot_stack: + .fill BOOT_STACK_SIZE, 1, 0 +boot_stack_end: diff --git a/arch/x86/boot/compressed/head_64.S b/arch/x86/boot/compressed/head_64.S new file mode 100644 index 000000000..1aca51390 --- /dev/null +++ b/arch/x86/boot/compressed/head_64.S @@ -0,0 +1,543 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * linux/boot/head.S + * + * Copyright (C) 1991, 1992, 1993 Linus Torvalds + */ + +/* + * head.S contains the 32-bit startup code. + * + * NOTE!!! Startup happens at absolute address 0x00001000, which is also where + * the page directory will exist. The startup code will be overwritten by + * the page directory. [According to comments etc elsewhere on a compressed + * kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC] + * + * Page 0 is deliberately kept safe, since System Management Mode code in + * laptops may need to access the BIOS data stored there. This is also + * useful for future device drivers that either access the BIOS via VM86 + * mode. + */ + +/* + * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 + */ + .code32 + .text + +#include <linux/init.h> +#include <linux/linkage.h> +#include <asm/segment.h> +#include <asm/boot.h> +#include <asm/msr.h> +#include <asm/processor-flags.h> +#include <asm/asm-offsets.h> +#include <asm/bootparam.h> +#include <asm/desc_defs.h> +#include <asm/trapnr.h> + +/* + * Fix alignment at 16 bytes. Following CONFIG_FUNCTION_ALIGNMENT will result + * in assembly errors due to trying to move .org backward due to the excessive + * alignment. + */ +#undef __ALIGN +#define __ALIGN .balign 16, 0x90 + +/* + * Locally defined symbols should be marked hidden: + */ + .hidden _bss + .hidden _ebss + .hidden _end + + __HEAD + +/* + * This macro gives the relative virtual address of X, i.e. the offset of X + * from startup_32. This is the same as the link-time virtual address of X, + * since startup_32 is at 0, but defining it this way tells the + * assembler/linker that we do not want the actual run-time address of X. This + * prevents the linker from trying to create unwanted run-time relocation + * entries for the reference when the compressed kernel is linked as PIE. + * + * A reference X(%reg) will result in the link-time VA of X being stored with + * the instruction, and a run-time R_X86_64_RELATIVE relocation entry that + * adds the 64-bit base address where the kernel is loaded. + * + * Replacing it with (X-startup_32)(%reg) results in the offset being stored, + * and no run-time relocation. + * + * The macro should be used as a displacement with a base register containing + * the run-time address of startup_32 [i.e. rva(X)(%reg)], or as an immediate + * [$ rva(X)]. + * + * This macro can only be used from within the .head.text section, since the + * expression requires startup_32 to be in the same section as the code being + * assembled. + */ +#define rva(X) ((X) - startup_32) + + .code32 +SYM_FUNC_START(startup_32) + /* + * 32bit entry is 0 and it is ABI so immutable! + * If we come here directly from a bootloader, + * kernel(text+data+bss+brk) ramdisk, zero_page, command line + * all need to be under the 4G limit. + */ + cld + cli + +/* + * Calculate the delta between where we were compiled to run + * at and where we were actually loaded at. This can only be done + * with a short local call on x86. Nothing else will tell us what + * address we are running at. The reserved chunk of the real-mode + * data at 0x1e4 (defined as a scratch field) are used as the stack + * for this calculation. Only 4 bytes are needed. + */ + leal (BP_scratch+4)(%esi), %esp + call 1f +1: popl %ebp + subl $ rva(1b), %ebp + + /* Load new GDT with the 64bit segments using 32bit descriptor */ + leal rva(gdt)(%ebp), %eax + movl %eax, 2(%eax) + lgdt (%eax) + + /* Load segment registers with our descriptors */ + movl $__BOOT_DS, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %fs + movl %eax, %gs + movl %eax, %ss + + /* Setup a stack and load CS from current GDT */ + leal rva(boot_stack_end)(%ebp), %esp + + pushl $__KERNEL32_CS + leal rva(1f)(%ebp), %eax + pushl %eax + lretl +1: + + /* Setup Exception handling for SEV-ES */ +#ifdef CONFIG_AMD_MEM_ENCRYPT + call startup32_load_idt +#endif + + /* Make sure cpu supports long mode. */ + call verify_cpu + testl %eax, %eax + jnz .Lno_longmode + +/* + * Compute the delta between where we were compiled to run at + * and where the code will actually run at. + * + * %ebp contains the address we are loaded at by the boot loader and %ebx + * contains the address where we should move the kernel image temporarily + * for safe in-place decompression. + */ + +#ifdef CONFIG_RELOCATABLE + movl %ebp, %ebx + movl BP_kernel_alignment(%esi), %eax + decl %eax + addl %eax, %ebx + notl %eax + andl %eax, %ebx + cmpl $LOAD_PHYSICAL_ADDR, %ebx + jae 1f +#endif + movl $LOAD_PHYSICAL_ADDR, %ebx +1: + + /* Target address to relocate to for decompression */ + addl BP_init_size(%esi), %ebx + subl $ rva(_end), %ebx + +/* + * Prepare for entering 64 bit mode + */ + + /* Enable PAE mode */ + movl %cr4, %eax + orl $X86_CR4_PAE, %eax + movl %eax, %cr4 + + /* + * Build early 4G boot pagetable + */ + xorl %edx, %edx +#ifdef CONFIG_AMD_MEM_ENCRYPT + call get_sev_encryption_bit + xorl %edx, %edx + testl %eax, %eax + jz 1f + + /* Encryption bit is always above bit 31 */ + subl $32, %eax + + /* + * If SEV is active then set the encryption mask in the page tables. + * This will ensure that when the kernel is copied and decompressed it + * will be done so encrypted. + */ + bts %eax, %edx + + /* + * Set MSR_AMD64_SEV_ENABLED_BIT in sev_status so that + * startup32_check_sev_cbit() will do a check. sev_enable() will + * initialize sev_status with all the bits reported by + * MSR_AMD_SEV_STATUS later, but only MSR_AMD64_SEV_ENABLED_BIT + * needs to be set for now. + */ + movl $1, rva(sev_status)(%ebp) +1: +#endif + + /* Initialize Page tables to 0 */ + leal rva(pgtable)(%ebx), %edi + xorl %eax, %eax + movl $(BOOT_INIT_PGT_SIZE/4), %ecx + rep stosl + + /* Build Level 4 */ + leal rva(pgtable + 0)(%ebx), %edi + leal 0x1007 (%edi), %eax + movl %eax, 0(%edi) + addl %edx, 4(%edi) + + /* Build Level 3 */ + leal rva(pgtable + 0x1000)(%ebx), %edi + leal 0x1007(%edi), %eax + movl $4, %ecx +1: movl %eax, 0x00(%edi) + addl %edx, 0x04(%edi) + addl $0x00001000, %eax + addl $8, %edi + decl %ecx + jnz 1b + + /* Build Level 2 */ + leal rva(pgtable + 0x2000)(%ebx), %edi + movl $0x00000183, %eax + movl $2048, %ecx +1: movl %eax, 0(%edi) + addl %edx, 4(%edi) + addl $0x00200000, %eax + addl $8, %edi + decl %ecx + jnz 1b + + /* Enable the boot page tables */ + leal rva(pgtable)(%ebx), %eax + movl %eax, %cr3 + + /* Enable Long mode in EFER (Extended Feature Enable Register) */ + movl $MSR_EFER, %ecx + rdmsr + btsl $_EFER_LME, %eax + wrmsr + + /* After gdt is loaded */ + xorl %eax, %eax + lldt %ax + movl $__BOOT_TSS, %eax + ltr %ax + +#ifdef CONFIG_AMD_MEM_ENCRYPT + /* Check if the C-bit position is correct when SEV is active */ + call startup32_check_sev_cbit +#endif + + /* + * Setup for the jump to 64bit mode + * + * When the jump is performed we will be in long mode but + * in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1 + * (and in turn EFER.LMA = 1). To jump into 64bit mode we use + * the new gdt/idt that has __KERNEL_CS with CS.L = 1. + * We place all of the values on our mini stack so lret can + * used to perform that far jump. + */ + leal rva(startup_64)(%ebp), %eax + pushl $__KERNEL_CS + pushl %eax + + /* Enter paged protected Mode, activating Long Mode */ + movl $CR0_STATE, %eax + movl %eax, %cr0 + + /* Jump from 32bit compatibility mode into 64bit mode. */ + lret +SYM_FUNC_END(startup_32) + + .code64 + .org 0x200 +SYM_CODE_START(startup_64) + /* + * 64bit entry is 0x200 and it is ABI so immutable! + * We come here either from startup_32 or directly from a + * 64bit bootloader. + * If we come here from a bootloader, kernel(text+data+bss+brk), + * ramdisk, zero_page, command line could be above 4G. + * We depend on an identity mapped page table being provided + * that maps our entire kernel(text+data+bss+brk), zero page + * and command line. + */ + + cld + cli + + /* Setup data segments. */ + xorl %eax, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %ss + movl %eax, %fs + movl %eax, %gs + + /* + * Compute the decompressed kernel start address. It is where + * we were loaded at aligned to a 2M boundary. %rbp contains the + * decompressed kernel start address. + * + * If it is a relocatable kernel then decompress and run the kernel + * from load address aligned to 2MB addr, otherwise decompress and + * run the kernel from LOAD_PHYSICAL_ADDR + * + * We cannot rely on the calculation done in 32-bit mode, since we + * may have been invoked via the 64-bit entry point. + */ + + /* Start with the delta to where the kernel will run at. */ +#ifdef CONFIG_RELOCATABLE + leaq startup_32(%rip) /* - $startup_32 */, %rbp + movl BP_kernel_alignment(%rsi), %eax + decl %eax + addq %rax, %rbp + notq %rax + andq %rax, %rbp + cmpq $LOAD_PHYSICAL_ADDR, %rbp + jae 1f +#endif + movq $LOAD_PHYSICAL_ADDR, %rbp +1: + + /* Target address to relocate to for decompression */ + movl BP_init_size(%rsi), %ebx + subl $ rva(_end), %ebx + addq %rbp, %rbx + + /* Set up the stack */ + leaq rva(boot_stack_end)(%rbx), %rsp + + /* + * At this point we are in long mode with 4-level paging enabled, + * but we might want to enable 5-level paging or vice versa. + * + * The problem is that we cannot do it directly. Setting or clearing + * CR4.LA57 in long mode would trigger #GP. So we need to switch off + * long mode and paging first. + * + * We also need a trampoline in lower memory to switch over from + * 4- to 5-level paging for cases when the bootloader puts the kernel + * above 4G, but didn't enable 5-level paging for us. + * + * The same trampoline can be used to switch from 5- to 4-level paging + * mode, like when starting 4-level paging kernel via kexec() when + * original kernel worked in 5-level paging mode. + * + * For the trampoline, we need the top page table to reside in lower + * memory as we don't have a way to load 64-bit values into CR3 in + * 32-bit mode. + */ + + /* Make sure we have GDT with 32-bit code segment */ + leaq gdt64(%rip), %rax + addq %rax, 2(%rax) + lgdt (%rax) + + /* Reload CS so IRET returns to a CS actually in the GDT */ + pushq $__KERNEL_CS + leaq .Lon_kernel_cs(%rip), %rax + pushq %rax + lretq + +.Lon_kernel_cs: + /* + * RSI holds a pointer to a boot_params structure provided by the + * loader, and this needs to be preserved across C function calls. So + * move it into a callee saved register. + */ + movq %rsi, %r15 + + call load_stage1_idt + +#ifdef CONFIG_AMD_MEM_ENCRYPT + /* + * Now that the stage1 interrupt handlers are set up, #VC exceptions from + * CPUID instructions can be properly handled for SEV-ES guests. + * + * For SEV-SNP, the CPUID table also needs to be set up in advance of any + * CPUID instructions being issued, so go ahead and do that now via + * sev_enable(), which will also handle the rest of the SEV-related + * detection/setup to ensure that has been done in advance of any dependent + * code. Pass the boot_params pointer as the first argument. + */ + movq %r15, %rdi + call sev_enable +#endif + + /* Preserve only the CR4 bits that must be preserved, and clear the rest */ + movq %cr4, %rax + andl $(X86_CR4_PAE | X86_CR4_MCE | X86_CR4_LA57), %eax + movq %rax, %cr4 + + /* + * configure_5level_paging() updates the number of paging levels using + * a trampoline in 32-bit addressable memory if the current number does + * not match the desired number. + * + * Pass the boot_params pointer as the first argument. The second + * argument is the relocated address of the page table to use instead + * of the page table in trampoline memory (if required). + */ + movq %r15, %rdi + leaq rva(top_pgtable)(%rbx), %rsi + call configure_5level_paging + + /* Zero EFLAGS */ + pushq $0 + popfq + +/* + * Copy the compressed kernel to the end of our buffer + * where decompression in place becomes safe. + */ + leaq (_bss-8)(%rip), %rsi + leaq rva(_bss-8)(%rbx), %rdi + movl $(_bss - startup_32), %ecx + shrl $3, %ecx + std + rep movsq + cld + + /* + * The GDT may get overwritten either during the copy we just did or + * during extract_kernel below. To avoid any issues, repoint the GDTR + * to the new copy of the GDT. + */ + leaq rva(gdt64)(%rbx), %rax + leaq rva(gdt)(%rbx), %rdx + movq %rdx, 2(%rax) + lgdt (%rax) + +/* + * Jump to the relocated address. + */ + leaq rva(.Lrelocated)(%rbx), %rax + jmp *%rax +SYM_CODE_END(startup_64) + + .text +SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated) + +/* + * Clear BSS (stack is currently empty) + */ + xorl %eax, %eax + leaq _bss(%rip), %rdi + leaq _ebss(%rip), %rcx + subq %rdi, %rcx + shrq $3, %rcx + rep stosq + + call load_stage2_idt + + /* Pass boot_params to initialize_identity_maps() */ + movq %r15, %rdi + call initialize_identity_maps + +/* + * Do the extraction, and jump to the new kernel.. + */ + /* pass struct boot_params pointer and output target address */ + movq %r15, %rdi + movq %rbp, %rsi + call extract_kernel /* returns kernel entry point in %rax */ + +/* + * Jump to the decompressed kernel. + */ + movq %r15, %rsi + jmp *%rax +SYM_FUNC_END(.Lrelocated) + + .code32 +SYM_FUNC_START_LOCAL_NOALIGN(.Lno_longmode) + /* This isn't an x86-64 CPU, so hang intentionally, we cannot continue */ +1: + hlt + jmp 1b +SYM_FUNC_END(.Lno_longmode) + + .globl verify_cpu +#include "../../kernel/verify_cpu.S" + + .data +SYM_DATA_START_LOCAL(gdt64) + .word gdt_end - gdt - 1 + .quad gdt - gdt64 +SYM_DATA_END(gdt64) + .balign 8 +SYM_DATA_START_LOCAL(gdt) + .word gdt_end - gdt - 1 + .long 0 + .word 0 + .quad 0x00cf9a000000ffff /* __KERNEL32_CS */ + .quad 0x00af9a000000ffff /* __KERNEL_CS */ + .quad 0x00cf92000000ffff /* __KERNEL_DS */ + .quad 0x0080890000000000 /* TS descriptor */ + .quad 0x0000000000000000 /* TS continued */ +SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end) + +SYM_DATA_START(boot_idt_desc) + .word boot_idt_end - boot_idt - 1 + .quad 0 +SYM_DATA_END(boot_idt_desc) + .balign 8 +SYM_DATA_START(boot_idt) + .rept BOOT_IDT_ENTRIES + .quad 0 + .quad 0 + .endr +SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end) + +/* + * Stack and heap for uncompression + */ + .bss + .balign 4 +SYM_DATA_START_LOCAL(boot_stack) + .fill BOOT_STACK_SIZE, 1, 0 + .balign 16 +SYM_DATA_END_LABEL(boot_stack, SYM_L_LOCAL, boot_stack_end) + +/* + * Space for page tables (not in .bss so not zeroed) + */ + .section ".pgtable","aw",@nobits + .balign 4096 +SYM_DATA_LOCAL(pgtable, .fill BOOT_PGT_SIZE, 1, 0) + +/* + * The page table is going to be used instead of page table in the trampoline + * memory. + */ +SYM_DATA_LOCAL(top_pgtable, .fill PAGE_SIZE, 1, 0) diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c new file mode 100644 index 000000000..dfb9c2deb --- /dev/null +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -0,0 +1,393 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This code is used on x86_64 to create page table identity mappings on + * demand by building up a new set of page tables (or appending to the + * existing ones), and then switching over to them when ready. + * + * Copyright (C) 2015-2016 Yinghai Lu + * Copyright (C) 2016 Kees Cook + */ + +/* No MITIGATION_PAGE_TABLE_ISOLATION support needed either: */ +#undef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION + +#include "error.h" +#include "misc.h" + +/* These actually do the work of building the kernel identity maps. */ +#include <linux/pgtable.h> +#include <asm/cmpxchg.h> +#include <asm/trap_pf.h> +#include <asm/trapnr.h> +#include <asm/init.h> +/* Use the static base for this part of the boot process */ +#undef __PAGE_OFFSET +#define __PAGE_OFFSET __PAGE_OFFSET_BASE +#include "../../mm/ident_map.c" + +#define _SETUP +#include <asm/setup.h> /* For COMMAND_LINE_SIZE */ +#undef _SETUP + +extern unsigned long get_cmd_line_ptr(void); + +/* Used by PAGE_KERN* macros: */ +pteval_t __default_kernel_pte_mask __read_mostly = ~0; + +/* Used to track our page table allocation area. */ +struct alloc_pgt_data { + unsigned char *pgt_buf; + unsigned long pgt_buf_size; + unsigned long pgt_buf_offset; +}; + +/* + * Allocates space for a page table entry, using struct alloc_pgt_data + * above. Besides the local callers, this is used as the allocation + * callback in mapping_info below. + */ +static void *alloc_pgt_page(void *context) +{ + struct alloc_pgt_data *pages = (struct alloc_pgt_data *)context; + unsigned char *entry; + + /* Validate there is space available for a new page. */ + if (pages->pgt_buf_offset >= pages->pgt_buf_size) { + debug_putstr("out of pgt_buf in " __FILE__ "!?\n"); + debug_putaddr(pages->pgt_buf_offset); + debug_putaddr(pages->pgt_buf_size); + return NULL; + } + + /* Consumed more tables than expected? */ + if (pages->pgt_buf_offset == BOOT_PGT_SIZE_WARN) { + debug_putstr("pgt_buf running low in " __FILE__ "\n"); + debug_putstr("Need to raise BOOT_PGT_SIZE?\n"); + debug_putaddr(pages->pgt_buf_offset); + debug_putaddr(pages->pgt_buf_size); + } + + entry = pages->pgt_buf + pages->pgt_buf_offset; + pages->pgt_buf_offset += PAGE_SIZE; + + return entry; +} + +/* Used to track our allocated page tables. */ +static struct alloc_pgt_data pgt_data; + +/* The top level page table entry pointer. */ +static unsigned long top_level_pgt; + +phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1; + +/* + * Mapping information structure passed to kernel_ident_mapping_init(). + * Due to relocation, pointers must be assigned at run time not build time. + */ +static struct x86_mapping_info mapping_info; + +/* + * Adds the specified range to the identity mappings. + */ +void kernel_add_identity_map(unsigned long start, unsigned long end) +{ + int ret; + + /* Align boundary to 2M. */ + start = round_down(start, PMD_SIZE); + end = round_up(end, PMD_SIZE); + if (start >= end) + return; + + /* Build the mapping. */ + ret = kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt, start, end); + if (ret) + error("Error: kernel_ident_mapping_init() failed\n"); +} + +/* Locates and clears a region for a new top level page table. */ +void initialize_identity_maps(void *rmode) +{ + unsigned long cmdline; + struct setup_data *sd; + + /* Exclude the encryption mask from __PHYSICAL_MASK */ + physical_mask &= ~sme_me_mask; + + /* Init mapping_info with run-time function/buffer pointers. */ + mapping_info.alloc_pgt_page = alloc_pgt_page; + mapping_info.context = &pgt_data; + mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask; + mapping_info.kernpg_flag = _KERNPG_TABLE; + + /* + * It should be impossible for this not to already be true, + * but since calling this a second time would rewind the other + * counters, let's just make sure this is reset too. + */ + pgt_data.pgt_buf_offset = 0; + + /* + * If we came here via startup_32(), cr3 will be _pgtable already + * and we must append to the existing area instead of entirely + * overwriting it. + * + * With 5-level paging, we use '_pgtable' to allocate the p4d page table, + * the top-level page table is allocated separately. + * + * p4d_offset(top_level_pgt, 0) would cover both the 4- and 5-level + * cases. On 4-level paging it's equal to 'top_level_pgt'. + */ + top_level_pgt = read_cr3_pa(); + if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) { + pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE; + pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE; + memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size); + } else { + pgt_data.pgt_buf = _pgtable; + pgt_data.pgt_buf_size = BOOT_PGT_SIZE; + memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size); + top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data); + } + + /* + * New page-table is set up - map the kernel image, boot_params and the + * command line. The uncompressed kernel requires boot_params and the + * command line to be mapped in the identity mapping. Map them + * explicitly here in case the compressed kernel does not touch them, + * or does not touch all the pages covering them. + */ + kernel_add_identity_map((unsigned long)_head, (unsigned long)_end); + boot_params_ptr = rmode; + kernel_add_identity_map((unsigned long)boot_params_ptr, + (unsigned long)(boot_params_ptr + 1)); + cmdline = get_cmd_line_ptr(); + kernel_add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE); + + /* + * Also map the setup_data entries passed via boot_params in case they + * need to be accessed by uncompressed kernel via the identity mapping. + */ + sd = (struct setup_data *)boot_params_ptr->hdr.setup_data; + while (sd) { + unsigned long sd_addr = (unsigned long)sd; + + kernel_add_identity_map(sd_addr, sd_addr + sizeof(*sd) + sd->len); + sd = (struct setup_data *)sd->next; + } + + sev_prep_identity_maps(top_level_pgt); + + /* Load the new page-table. */ + write_cr3(top_level_pgt); + + /* + * Now that the required page table mappings are established and a + * GHCB can be used, check for SNP guest/HV feature compatibility. + */ + snp_check_features(); +} + +static pte_t *split_large_pmd(struct x86_mapping_info *info, + pmd_t *pmdp, unsigned long __address) +{ + unsigned long page_flags; + unsigned long address; + pte_t *pte; + pmd_t pmd; + int i; + + pte = (pte_t *)info->alloc_pgt_page(info->context); + if (!pte) + return NULL; + + address = __address & PMD_MASK; + /* No large page - clear PSE flag */ + page_flags = info->page_flag & ~_PAGE_PSE; + + /* Populate the PTEs */ + for (i = 0; i < PTRS_PER_PMD; i++) { + set_pte(&pte[i], __pte(address | page_flags)); + address += PAGE_SIZE; + } + + /* + * Ideally we need to clear the large PMD first and do a TLB + * flush before we write the new PMD. But the 2M range of the + * PMD might contain the code we execute and/or the stack + * we are on, so we can't do that. But that should be safe here + * because we are going from large to small mappings and we are + * also the only user of the page-table, so there is no chance + * of a TLB multihit. + */ + pmd = __pmd((unsigned long)pte | info->kernpg_flag); + set_pmd(pmdp, pmd); + /* Flush TLB to establish the new PMD */ + write_cr3(top_level_pgt); + + return pte + pte_index(__address); +} + +static void clflush_page(unsigned long address) +{ + unsigned int flush_size; + char *cl, *start, *end; + + /* + * Hardcode cl-size to 64 - CPUID can't be used here because that might + * cause another #VC exception and the GHCB is not ready to use yet. + */ + flush_size = 64; + start = (char *)(address & PAGE_MASK); + end = start + PAGE_SIZE; + + /* + * First make sure there are no pending writes on the cache-lines to + * flush. + */ + asm volatile("mfence" : : : "memory"); + + for (cl = start; cl != end; cl += flush_size) + clflush(cl); +} + +static int set_clr_page_flags(struct x86_mapping_info *info, + unsigned long address, + pteval_t set, pteval_t clr) +{ + pgd_t *pgdp = (pgd_t *)top_level_pgt; + p4d_t *p4dp; + pud_t *pudp; + pmd_t *pmdp; + pte_t *ptep, pte; + + /* + * First make sure there is a PMD mapping for 'address'. + * It should already exist, but keep things generic. + * + * To map the page just read from it and fault it in if there is no + * mapping yet. kernel_add_identity_map() can't be called here because + * that would unconditionally map the address on PMD level, destroying + * any PTE-level mappings that might already exist. Use assembly here + * so the access won't be optimized away. + */ + asm volatile("mov %[address], %%r9" + :: [address] "g" (*(unsigned long *)address) + : "r9", "memory"); + + /* + * The page is mapped at least with PMD size - so skip checks and walk + * directly to the PMD. + */ + p4dp = p4d_offset(pgdp, address); + pudp = pud_offset(p4dp, address); + pmdp = pmd_offset(pudp, address); + + if (pmd_leaf(*pmdp)) + ptep = split_large_pmd(info, pmdp, address); + else + ptep = pte_offset_kernel(pmdp, address); + + if (!ptep) + return -ENOMEM; + + /* + * Changing encryption attributes of a page requires to flush it from + * the caches. + */ + if ((set | clr) & _PAGE_ENC) { + clflush_page(address); + + /* + * If the encryption attribute is being cleared, change the page state + * to shared in the RMP table. + */ + if (clr) + snp_set_page_shared(__pa(address & PAGE_MASK)); + } + + /* Update PTE */ + pte = *ptep; + pte = pte_set_flags(pte, set); + pte = pte_clear_flags(pte, clr); + set_pte(ptep, pte); + + /* + * If the encryption attribute is being set, then change the page state to + * private in the RMP entry. The page state change must be done after the PTE + * is updated. + */ + if (set & _PAGE_ENC) + snp_set_page_private(__pa(address & PAGE_MASK)); + + /* Flush TLB after changing encryption attribute */ + write_cr3(top_level_pgt); + + return 0; +} + +int set_page_decrypted(unsigned long address) +{ + return set_clr_page_flags(&mapping_info, address, 0, _PAGE_ENC); +} + +int set_page_encrypted(unsigned long address) +{ + return set_clr_page_flags(&mapping_info, address, _PAGE_ENC, 0); +} + +int set_page_non_present(unsigned long address) +{ + return set_clr_page_flags(&mapping_info, address, 0, _PAGE_PRESENT); +} + +static void do_pf_error(const char *msg, unsigned long error_code, + unsigned long address, unsigned long ip) +{ + error_putstr(msg); + + error_putstr("\nError Code: "); + error_puthex(error_code); + error_putstr("\nCR2: 0x"); + error_puthex(address); + error_putstr("\nRIP relative to _head: 0x"); + error_puthex(ip - (unsigned long)_head); + error_putstr("\n"); + + error("Stopping.\n"); +} + +void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code) +{ + unsigned long address = native_read_cr2(); + unsigned long end; + bool ghcb_fault; + + ghcb_fault = sev_es_check_ghcb_fault(address); + + address &= PMD_MASK; + end = address + PMD_SIZE; + + /* + * Check for unexpected error codes. Unexpected are: + * - Faults on present pages + * - User faults + * - Reserved bits set + */ + if (error_code & (X86_PF_PROT | X86_PF_USER | X86_PF_RSVD)) + do_pf_error("Unexpected page-fault:", error_code, address, regs->ip); + else if (ghcb_fault) + do_pf_error("Page-fault on GHCB page:", error_code, address, regs->ip); + + /* + * Error code is sane - now identity map the 2M region around + * the faulting address. + */ + kernel_add_identity_map(address, end); +} + +void do_boot_nmi_trap(struct pt_regs *regs, unsigned long error_code) +{ + spurious_nmi_count++; +} diff --git a/arch/x86/boot/compressed/idt_64.c b/arch/x86/boot/compressed/idt_64.c new file mode 100644 index 000000000..d100284bb --- /dev/null +++ b/arch/x86/boot/compressed/idt_64.c @@ -0,0 +1,92 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <asm/trap_pf.h> +#include <asm/segment.h> +#include <asm/trapnr.h> +#include "misc.h" + +static void set_idt_entry(int vector, void (*handler)(void)) +{ + unsigned long address = (unsigned long)handler; + gate_desc entry; + + memset(&entry, 0, sizeof(entry)); + + entry.offset_low = (u16)(address & 0xffff); + entry.segment = __KERNEL_CS; + entry.bits.type = GATE_TRAP; + entry.bits.p = 1; + entry.offset_middle = (u16)((address >> 16) & 0xffff); + entry.offset_high = (u32)(address >> 32); + + memcpy(&boot_idt[vector], &entry, sizeof(entry)); +} + +/* Have this here so we don't need to include <asm/desc.h> */ +static void load_boot_idt(const struct desc_ptr *dtr) +{ + asm volatile("lidt %0"::"m" (*dtr)); +} + +/* Setup IDT before kernel jumping to .Lrelocated */ +void load_stage1_idt(void) +{ + boot_idt_desc.address = (unsigned long)boot_idt; + + + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) + set_idt_entry(X86_TRAP_VC, boot_stage1_vc); + + load_boot_idt(&boot_idt_desc); +} + +/* + * Setup IDT after kernel jumping to .Lrelocated. + * + * initialize_identity_maps() needs a #PF handler to be setup + * in order to be able to fault-in identity mapping ranges; see + * do_boot_page_fault(). + * + * This #PF handler setup needs to happen in load_stage2_idt() where the + * IDT is loaded and there the #VC IDT entry gets setup too. + * + * In order to be able to handle #VCs, one needs a GHCB which + * gets setup with an already set up pagetable, which is done in + * initialize_identity_maps(). And there's the catch 22: the boot #VC + * handler do_boot_stage2_vc() needs to call early_setup_ghcb() itself + * (and, especially set_page_decrypted()) because the SEV-ES setup code + * cannot initialize a GHCB as there's no #PF handler yet... + */ +void load_stage2_idt(void) +{ + boot_idt_desc.address = (unsigned long)boot_idt; + + set_idt_entry(X86_TRAP_PF, boot_page_fault); + set_idt_entry(X86_TRAP_NMI, boot_nmi_trap); + +#ifdef CONFIG_AMD_MEM_ENCRYPT + /* + * Clear the second stage #VC handler in case guest types + * needing #VC have not been detected. + */ + if (sev_status & BIT(1)) + set_idt_entry(X86_TRAP_VC, boot_stage2_vc); + else + set_idt_entry(X86_TRAP_VC, NULL); +#endif + + load_boot_idt(&boot_idt_desc); +} + +void cleanup_exception_handling(void) +{ + /* + * Flush GHCB from cache and map it encrypted again when running as + * SEV-ES guest. + */ + sev_es_shutdown_ghcb(); + + /* Set a null-idt, disabling #PF and #VC handling */ + boot_idt_desc.size = 0; + boot_idt_desc.address = 0; + load_boot_idt(&boot_idt_desc); +} diff --git a/arch/x86/boot/compressed/idt_handlers_64.S b/arch/x86/boot/compressed/idt_handlers_64.S new file mode 100644 index 000000000..4d03c8562 --- /dev/null +++ b/arch/x86/boot/compressed/idt_handlers_64.S @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Early IDT handler entry points + * + * Copyright (C) 2019 SUSE + * + * Author: Joerg Roedel <jroedel@suse.de> + */ + +#include <asm/segment.h> + +/* For ORIG_RAX */ +#include "../../entry/calling.h" + +.macro EXCEPTION_HANDLER name function error_code=0 +SYM_FUNC_START(\name) + + /* Build pt_regs */ + .if \error_code == 0 + pushq $0 + .endif + + pushq %rdi + pushq %rsi + pushq %rdx + pushq %rcx + pushq %rax + pushq %r8 + pushq %r9 + pushq %r10 + pushq %r11 + pushq %rbx + pushq %rbp + pushq %r12 + pushq %r13 + pushq %r14 + pushq %r15 + + /* Call handler with pt_regs */ + movq %rsp, %rdi + /* Error code is second parameter */ + movq ORIG_RAX(%rsp), %rsi + call \function + + /* Restore regs */ + popq %r15 + popq %r14 + popq %r13 + popq %r12 + popq %rbp + popq %rbx + popq %r11 + popq %r10 + popq %r9 + popq %r8 + popq %rax + popq %rcx + popq %rdx + popq %rsi + popq %rdi + + /* Remove error code and return */ + addq $8, %rsp + + iretq +SYM_FUNC_END(\name) + .endm + + .text + .code64 + +EXCEPTION_HANDLER boot_page_fault do_boot_page_fault error_code=1 +EXCEPTION_HANDLER boot_nmi_trap do_boot_nmi_trap error_code=0 + +#ifdef CONFIG_AMD_MEM_ENCRYPT +EXCEPTION_HANDLER boot_stage1_vc do_vc_no_ghcb error_code=1 +EXCEPTION_HANDLER boot_stage2_vc do_boot_stage2_vc error_code=1 +#endif diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c new file mode 100644 index 000000000..22267a83e --- /dev/null +++ b/arch/x86/boot/compressed/kaslr.c @@ -0,0 +1,911 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * kaslr.c + * + * This contains the routines needed to generate a reasonable level of + * entropy to choose a randomized kernel base address offset in support + * of Kernel Address Space Layout Randomization (KASLR). Additionally + * handles walking the physical memory maps (and tracking memory regions + * to avoid) in order to select a physical memory location that can + * contain the entire properly aligned running kernel image. + * + */ + +/* + * isspace() in linux/ctype.h is expected by next_args() to filter + * out "space/lf/tab". While boot/ctype.h conflicts with linux/ctype.h, + * since isdigit() is implemented in both of them. Hence disable it + * here. + */ +#define BOOT_CTYPE_H + +#include "misc.h" +#include "error.h" +#include "../string.h" +#include "efi.h" + +#include <generated/compile.h> +#include <generated/utsversion.h> +#include <generated/utsrelease.h> + +#define _SETUP +#include <asm/setup.h> /* For COMMAND_LINE_SIZE */ +#undef _SETUP + +#include <asm/kexec_handover.h> + +extern unsigned long get_cmd_line_ptr(void); + +/* Simplified build-specific string for starting entropy. */ +static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@" + LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION; + +static unsigned long rotate_xor(unsigned long hash, const void *area, + size_t size) +{ + size_t i; + unsigned long *ptr = (unsigned long *)area; + + for (i = 0; i < size / sizeof(hash); i++) { + /* Rotate by odd number of bits and XOR. */ + hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7); + hash ^= ptr[i]; + } + + return hash; +} + +/* Attempt to create a simple but unpredictable starting entropy. */ +static unsigned long get_boot_seed(void) +{ + unsigned long hash = 0; + + hash = rotate_xor(hash, build_str, sizeof(build_str)); + hash = rotate_xor(hash, boot_params_ptr, sizeof(*boot_params_ptr)); + + return hash; +} + +#define KASLR_COMPRESSED_BOOT +#include "../../lib/kaslr.c" + + +/* Only supporting at most 4 unusable memmap regions with kaslr */ +#define MAX_MEMMAP_REGIONS 4 + +static bool memmap_too_large; + + +/* + * Store memory limit: MAXMEM on 64-bit and KERNEL_IMAGE_SIZE on 32-bit. + * It may be reduced by "mem=nn[KMG]" or "memmap=nn[KMG]" command line options. + */ +static u64 mem_limit; + +/* Number of immovable memory regions */ +static int num_immovable_mem; + +enum mem_avoid_index { + MEM_AVOID_ZO_RANGE = 0, + MEM_AVOID_INITRD, + MEM_AVOID_CMDLINE, + MEM_AVOID_BOOTPARAMS, + MEM_AVOID_MEMMAP_BEGIN, + MEM_AVOID_MEMMAP_END = MEM_AVOID_MEMMAP_BEGIN + MAX_MEMMAP_REGIONS - 1, + MEM_AVOID_MAX, +}; + +static struct mem_vector mem_avoid[MEM_AVOID_MAX]; + +static bool mem_overlaps(struct mem_vector *one, struct mem_vector *two) +{ + /* Item one is entirely before item two. */ + if (one->start + one->size <= two->start) + return false; + /* Item one is entirely after item two. */ + if (one->start >= two->start + two->size) + return false; + return true; +} + +char *skip_spaces(const char *str) +{ + while (isspace(*str)) + ++str; + return (char *)str; +} +#include "../../../../lib/ctype.c" +#include "../../../../lib/cmdline.c" + +static int +parse_memmap(char *p, u64 *start, u64 *size) +{ + char *oldp; + + if (!p) + return -EINVAL; + + /* We don't care about this option here */ + if (!strncmp(p, "exactmap", 8)) + return -EINVAL; + + oldp = p; + *size = memparse(p, &p); + if (p == oldp) + return -EINVAL; + + switch (*p) { + case '#': + case '$': + case '!': + *start = memparse(p + 1, &p); + return 0; + case '@': + /* + * memmap=nn@ss specifies usable region, should + * be skipped + */ + *size = 0; + fallthrough; + default: + /* + * If w/o offset, only size specified, memmap=nn[KMG] has the + * same behaviour as mem=nn[KMG]. It limits the max address + * system can use. Region above the limit should be avoided. + */ + *start = 0; + return 0; + } + + return -EINVAL; +} + +static void mem_avoid_memmap(char *str) +{ + static int i; + + if (i >= MAX_MEMMAP_REGIONS) + return; + + while (str && (i < MAX_MEMMAP_REGIONS)) { + int rc; + u64 start, size; + char *k = strchr(str, ','); + + if (k) + *k++ = 0; + + rc = parse_memmap(str, &start, &size); + if (rc < 0) + break; + str = k; + + if (start == 0) { + /* Store the specified memory limit if size > 0 */ + if (size > 0 && size < mem_limit) + mem_limit = size; + + continue; + } + + mem_avoid[MEM_AVOID_MEMMAP_BEGIN + i].start = start; + mem_avoid[MEM_AVOID_MEMMAP_BEGIN + i].size = size; + i++; + } + + /* More than 4 memmaps, fail kaslr */ + if ((i >= MAX_MEMMAP_REGIONS) && str) + memmap_too_large = true; +} + +/* Store the number of 1GB huge pages which users specified: */ +static unsigned long max_gb_huge_pages; + +static void parse_gb_huge_pages(char *param, char *val) +{ + static bool gbpage_sz; + char *p; + + if (!strcmp(param, "hugepagesz")) { + p = val; + if (memparse(p, &p) != PUD_SIZE) { + gbpage_sz = false; + return; + } + + if (gbpage_sz) + warn("Repeatedly set hugeTLB page size of 1G!\n"); + gbpage_sz = true; + return; + } + + if (!strcmp(param, "hugepages") && gbpage_sz) { + p = val; + if (boot_kstrtoul(p, 0, &max_gb_huge_pages)) + warn("Failed to parse hugepages= boot parameter\n"); + return; + } +} + +static void handle_mem_options(void) +{ + char *args = (char *)get_cmd_line_ptr(); + size_t len; + char *tmp_cmdline; + char *param, *val; + u64 mem_size; + + if (!args) + return; + + len = strnlen(args, COMMAND_LINE_SIZE-1); + tmp_cmdline = malloc(len + 1); + if (!tmp_cmdline) + error("Failed to allocate space for tmp_cmdline"); + + memcpy(tmp_cmdline, args, len); + tmp_cmdline[len] = 0; + args = tmp_cmdline; + + /* Chew leading spaces */ + args = skip_spaces(args); + + while (*args) { + args = next_arg(args, ¶m, &val); + /* Stop at -- */ + if (!val && strcmp(param, "--") == 0) + break; + + if (!strcmp(param, "memmap")) { + mem_avoid_memmap(val); + } else if (IS_ENABLED(CONFIG_X86_64) && strstr(param, "hugepages")) { + parse_gb_huge_pages(param, val); + } else if (!strcmp(param, "mem")) { + char *p = val; + + if (!strcmp(p, "nopentium")) + continue; + mem_size = memparse(p, &p); + if (mem_size == 0) + break; + + if (mem_size < mem_limit) + mem_limit = mem_size; + } + } + + free(tmp_cmdline); + return; +} + +/* + * In theory, KASLR can put the kernel anywhere in the range of [16M, MAXMEM) + * on 64-bit, and [16M, KERNEL_IMAGE_SIZE) on 32-bit. + * + * The mem_avoid array is used to store the ranges that need to be avoided + * when KASLR searches for an appropriate random address. We must avoid any + * regions that are unsafe to overlap with during decompression, and other + * things like the initrd, cmdline and boot_params. This comment seeks to + * explain mem_avoid as clearly as possible since incorrect mem_avoid + * memory ranges lead to really hard to debug boot failures. + * + * The initrd, cmdline, and boot_params are trivial to identify for + * avoiding. They are MEM_AVOID_INITRD, MEM_AVOID_CMDLINE, and + * MEM_AVOID_BOOTPARAMS respectively below. + * + * What is not obvious how to avoid is the range of memory that is used + * during decompression (MEM_AVOID_ZO_RANGE below). This range must cover + * the compressed kernel (ZO) and its run space, which is used to extract + * the uncompressed kernel (VO) and relocs. + * + * ZO's full run size sits against the end of the decompression buffer, so + * we can calculate where text, data, bss, etc of ZO are positioned more + * easily. + * + * For additional background, the decompression calculations can be found + * in header.S, and the memory diagram is based on the one found in misc.c. + * + * The following conditions are already enforced by the image layouts and + * associated code: + * - input + input_size >= output + output_size + * - kernel_total_size <= init_size + * - kernel_total_size <= output_size (see Note below) + * - output + init_size >= output + output_size + * + * (Note that kernel_total_size and output_size have no fundamental + * relationship, but output_size is passed to choose_random_location + * as a maximum of the two. The diagram is showing a case where + * kernel_total_size is larger than output_size, but this case is + * handled by bumping output_size.) + * + * The above conditions can be illustrated by a diagram: + * + * 0 output input input+input_size output+init_size + * | | | | | + * | | | | | + * |-----|--------|--------|--------------|-----------|--|-------------| + * | | | + * | | | + * output+init_size-ZO_INIT_SIZE output+output_size output+kernel_total_size + * + * [output, output+init_size) is the entire memory range used for + * extracting the compressed image. + * + * [output, output+kernel_total_size) is the range needed for the + * uncompressed kernel (VO) and its run size (bss, brk, etc). + * + * [output, output+output_size) is VO plus relocs (i.e. the entire + * uncompressed payload contained by ZO). This is the area of the buffer + * written to during decompression. + * + * [output+init_size-ZO_INIT_SIZE, output+init_size) is the worst-case + * range of the copied ZO and decompression code. (i.e. the range + * covered backwards of size ZO_INIT_SIZE, starting from output+init_size.) + * + * [input, input+input_size) is the original copied compressed image (ZO) + * (i.e. it does not include its run size). This range must be avoided + * because it contains the data used for decompression. + * + * [input+input_size, output+init_size) is [_text, _end) for ZO. This + * range includes ZO's heap and stack, and must be avoided since it + * performs the decompression. + * + * Since the above two ranges need to be avoided and they are adjacent, + * they can be merged, resulting in: [input, output+init_size) which + * becomes the MEM_AVOID_ZO_RANGE below. + */ +static void mem_avoid_init(unsigned long input, unsigned long input_size, + unsigned long output) +{ + unsigned long init_size = boot_params_ptr->hdr.init_size; + u64 initrd_start, initrd_size; + unsigned long cmd_line, cmd_line_size; + + /* + * Avoid the region that is unsafe to overlap during + * decompression. + */ + mem_avoid[MEM_AVOID_ZO_RANGE].start = input; + mem_avoid[MEM_AVOID_ZO_RANGE].size = (output + init_size) - input; + + /* Avoid initrd. */ + initrd_start = (u64)boot_params_ptr->ext_ramdisk_image << 32; + initrd_start |= boot_params_ptr->hdr.ramdisk_image; + initrd_size = (u64)boot_params_ptr->ext_ramdisk_size << 32; + initrd_size |= boot_params_ptr->hdr.ramdisk_size; + mem_avoid[MEM_AVOID_INITRD].start = initrd_start; + mem_avoid[MEM_AVOID_INITRD].size = initrd_size; + /* No need to set mapping for initrd, it will be handled in VO. */ + + /* Avoid kernel command line. */ + cmd_line = get_cmd_line_ptr(); + /* Calculate size of cmd_line. */ + if (cmd_line) { + cmd_line_size = strnlen((char *)cmd_line, COMMAND_LINE_SIZE-1) + 1; + mem_avoid[MEM_AVOID_CMDLINE].start = cmd_line; + mem_avoid[MEM_AVOID_CMDLINE].size = cmd_line_size; + } + + /* Avoid boot parameters. */ + mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params_ptr; + mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params_ptr); + + /* We don't need to set a mapping for setup_data. */ + + /* Mark the memmap regions we need to avoid */ + handle_mem_options(); + + /* Enumerate the immovable memory regions */ + num_immovable_mem = count_immovable_mem_regions(); +} + +/* + * Does this memory vector overlap a known avoided area? If so, record the + * overlap region with the lowest address. + */ +static bool mem_avoid_overlap(struct mem_vector *img, + struct mem_vector *overlap) +{ + int i; + struct setup_data *ptr; + u64 earliest = img->start + img->size; + bool is_overlapping = false; + + for (i = 0; i < MEM_AVOID_MAX; i++) { + if (mem_overlaps(img, &mem_avoid[i]) && + mem_avoid[i].start < earliest) { + *overlap = mem_avoid[i]; + earliest = overlap->start; + is_overlapping = true; + } + } + + /* Avoid all entries in the setup_data linked list. */ + ptr = (struct setup_data *)(unsigned long)boot_params_ptr->hdr.setup_data; + while (ptr) { + struct mem_vector avoid; + + avoid.start = (unsigned long)ptr; + avoid.size = sizeof(*ptr) + ptr->len; + + if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) { + *overlap = avoid; + earliest = overlap->start; + is_overlapping = true; + } + + if (ptr->type == SETUP_INDIRECT && + ((struct setup_indirect *)ptr->data)->type != SETUP_INDIRECT) { + avoid.start = ((struct setup_indirect *)ptr->data)->addr; + avoid.size = ((struct setup_indirect *)ptr->data)->len; + + if (mem_overlaps(img, &avoid) && (avoid.start < earliest)) { + *overlap = avoid; + earliest = overlap->start; + is_overlapping = true; + } + } + + ptr = (struct setup_data *)(unsigned long)ptr->next; + } + + return is_overlapping; +} + +struct slot_area { + u64 addr; + unsigned long num; +}; + +#define MAX_SLOT_AREA 100 + +static struct slot_area slot_areas[MAX_SLOT_AREA]; +static unsigned int slot_area_index; +static unsigned long slot_max; + +static void store_slot_info(struct mem_vector *region, unsigned long image_size) +{ + struct slot_area slot_area; + + if (slot_area_index == MAX_SLOT_AREA) + return; + + slot_area.addr = region->start; + slot_area.num = 1 + (region->size - image_size) / CONFIG_PHYSICAL_ALIGN; + + slot_areas[slot_area_index++] = slot_area; + slot_max += slot_area.num; +} + +/* + * Skip as many 1GB huge pages as possible in the passed region + * according to the number which users specified: + */ +static void +process_gb_huge_pages(struct mem_vector *region, unsigned long image_size) +{ + u64 pud_start, pud_end; + unsigned long gb_huge_pages; + struct mem_vector tmp; + + if (!IS_ENABLED(CONFIG_X86_64) || !max_gb_huge_pages) { + store_slot_info(region, image_size); + return; + } + + /* Are there any 1GB pages in the region? */ + pud_start = ALIGN(region->start, PUD_SIZE); + pud_end = ALIGN_DOWN(region->start + region->size, PUD_SIZE); + + /* No good 1GB huge pages found: */ + if (pud_start >= pud_end) { + store_slot_info(region, image_size); + return; + } + + /* Check if the head part of the region is usable. */ + if (pud_start >= region->start + image_size) { + tmp.start = region->start; + tmp.size = pud_start - region->start; + store_slot_info(&tmp, image_size); + } + + /* Skip the good 1GB pages. */ + gb_huge_pages = (pud_end - pud_start) >> PUD_SHIFT; + if (gb_huge_pages > max_gb_huge_pages) { + pud_end = pud_start + (max_gb_huge_pages << PUD_SHIFT); + max_gb_huge_pages = 0; + } else { + max_gb_huge_pages -= gb_huge_pages; + } + + /* Check if the tail part of the region is usable. */ + if (region->start + region->size >= pud_end + image_size) { + tmp.start = pud_end; + tmp.size = region->start + region->size - pud_end; + store_slot_info(&tmp, image_size); + } +} + +static u64 slots_fetch_random(void) +{ + unsigned long slot; + unsigned int i; + + /* Handle case of no slots stored. */ + if (slot_max == 0) + return 0; + + slot = kaslr_get_random_long("Physical") % slot_max; + + for (i = 0; i < slot_area_index; i++) { + if (slot >= slot_areas[i].num) { + slot -= slot_areas[i].num; + continue; + } + return slot_areas[i].addr + ((u64)slot * CONFIG_PHYSICAL_ALIGN); + } + + if (i == slot_area_index) + debug_putstr("slots_fetch_random() failed!?\n"); + return 0; +} + +static void __process_mem_region(struct mem_vector *entry, + unsigned long minimum, + unsigned long image_size) +{ + struct mem_vector region, overlap; + u64 region_end; + + /* Enforce minimum and memory limit. */ + region.start = max_t(u64, entry->start, minimum); + region_end = min(entry->start + entry->size, mem_limit); + + /* Give up if slot area array is full. */ + while (slot_area_index < MAX_SLOT_AREA) { + /* Potentially raise address to meet alignment needs. */ + region.start = ALIGN(region.start, CONFIG_PHYSICAL_ALIGN); + + /* Did we raise the address above the passed in memory entry? */ + if (region.start > region_end) + return; + + /* Reduce size by any delta from the original address. */ + region.size = region_end - region.start; + + /* Return if region can't contain decompressed kernel */ + if (region.size < image_size) + return; + + /* If nothing overlaps, store the region and return. */ + if (!mem_avoid_overlap(®ion, &overlap)) { + process_gb_huge_pages(®ion, image_size); + return; + } + + /* Store beginning of region if holds at least image_size. */ + if (overlap.start >= region.start + image_size) { + region.size = overlap.start - region.start; + process_gb_huge_pages(®ion, image_size); + } + + /* Clip off the overlapping region and start over. */ + region.start = overlap.start + overlap.size; + } +} + +static bool process_mem_region(struct mem_vector *region, + unsigned long minimum, + unsigned long image_size) +{ + int i; + /* + * If no immovable memory found, or MEMORY_HOTREMOVE disabled, + * use @region directly. + */ + if (!num_immovable_mem) { + __process_mem_region(region, minimum, image_size); + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan (slot_areas full)!\n"); + return true; + } + return false; + } + +#if defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI) + /* + * If immovable memory found, filter the intersection between + * immovable memory and @region. + */ + for (i = 0; i < num_immovable_mem; i++) { + u64 start, end, entry_end, region_end; + struct mem_vector entry; + + if (!mem_overlaps(region, &immovable_mem[i])) + continue; + + start = immovable_mem[i].start; + end = start + immovable_mem[i].size; + region_end = region->start + region->size; + + entry.start = clamp(region->start, start, end); + entry_end = clamp(region_end, start, end); + entry.size = entry_end - entry.start; + + __process_mem_region(&entry, minimum, image_size); + + if (slot_area_index == MAX_SLOT_AREA) { + debug_putstr("Aborted e820/efi memmap scan when walking immovable regions(slot_areas full)!\n"); + return true; + } + } +#endif + return false; +} + +#ifdef CONFIG_EFI + +/* + * Only EFI_CONVENTIONAL_MEMORY and EFI_UNACCEPTED_MEMORY (if supported) are + * guaranteed to be free. + * + * Pick free memory more conservatively than the EFI spec allows: according to + * the spec, EFI_BOOT_SERVICES_{CODE|DATA} are also free memory and thus + * available to place the kernel image into, but in practice there's firmware + * where using that memory leads to crashes. Buggy vendor EFI code registers + * for an event that triggers on SetVirtualAddressMap(). The handler assumes + * that EFI_BOOT_SERVICES_DATA memory has not been touched by loader yet, which + * is probably true for Windows. + * + * Preserve EFI_BOOT_SERVICES_* regions until after SetVirtualAddressMap(). + */ +static inline bool memory_type_is_free(efi_memory_desc_t *md) +{ + if (md->type == EFI_CONVENTIONAL_MEMORY) + return true; + + if (IS_ENABLED(CONFIG_UNACCEPTED_MEMORY) && + md->type == EFI_UNACCEPTED_MEMORY) + return true; + + return false; +} + +/* + * Returns true if we processed the EFI memmap, which we prefer over the E820 + * table if it is available. + */ +static bool +process_efi_entries(unsigned long minimum, unsigned long image_size) +{ + struct efi_info *e = &boot_params_ptr->efi_info; + bool efi_mirror_found = false; + struct mem_vector region; + efi_memory_desc_t *md; + unsigned long pmap; + char *signature; + u32 nr_desc; + int i; + + signature = (char *)&e->efi_loader_signature; + if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) && + strncmp(signature, EFI64_LOADER_SIGNATURE, 4)) + return false; + +#ifdef CONFIG_X86_32 + /* Can't handle data above 4GB at this time */ + if (e->efi_memmap_hi) { + warn("EFI memmap is above 4GB, can't be handled now on x86_32. EFI should be disabled.\n"); + return false; + } + pmap = e->efi_memmap; +#else + pmap = (e->efi_memmap | ((__u64)e->efi_memmap_hi << 32)); +#endif + + nr_desc = e->efi_memmap_size / e->efi_memdesc_size; + for (i = 0; i < nr_desc; i++) { + md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); + if (md->attribute & EFI_MEMORY_MORE_RELIABLE) { + efi_mirror_found = true; + break; + } + } + + for (i = 0; i < nr_desc; i++) { + md = efi_early_memdesc_ptr(pmap, e->efi_memdesc_size, i); + + if (!memory_type_is_free(md)) + continue; + + if (efi_soft_reserve_enabled() && + (md->attribute & EFI_MEMORY_SP)) + continue; + + if (efi_mirror_found && + !(md->attribute & EFI_MEMORY_MORE_RELIABLE)) + continue; + + region.start = md->phys_addr; + region.size = md->num_pages << EFI_PAGE_SHIFT; + if (process_mem_region(®ion, minimum, image_size)) + break; + } + return true; +} +#else +static inline bool +process_efi_entries(unsigned long minimum, unsigned long image_size) +{ + return false; +} +#endif + +static void process_e820_entries(unsigned long minimum, + unsigned long image_size) +{ + int i; + struct mem_vector region; + struct boot_e820_entry *entry; + + /* Verify potential e820 positions, appending to slots list. */ + for (i = 0; i < boot_params_ptr->e820_entries; i++) { + entry = &boot_params_ptr->e820_table[i]; + /* Skip non-RAM entries. */ + if (entry->type != E820_TYPE_RAM) + continue; + region.start = entry->addr; + region.size = entry->size; + if (process_mem_region(®ion, minimum, image_size)) + break; + } +} + +/* + * If KHO is active, only process its scratch areas to ensure we are not + * stepping onto preserved memory. + */ +static bool process_kho_entries(unsigned long minimum, unsigned long image_size) +{ + struct kho_scratch *kho_scratch; + struct setup_data *ptr; + struct kho_data *kho; + int i, nr_areas = 0; + + if (!IS_ENABLED(CONFIG_KEXEC_HANDOVER)) + return false; + + ptr = (struct setup_data *)(unsigned long)boot_params_ptr->hdr.setup_data; + while (ptr) { + if (ptr->type == SETUP_KEXEC_KHO) { + kho = (struct kho_data *)(unsigned long)ptr->data; + kho_scratch = (void *)(unsigned long)kho->scratch_addr; + nr_areas = kho->scratch_size / sizeof(*kho_scratch); + break; + } + + ptr = (struct setup_data *)(unsigned long)ptr->next; + } + + if (!nr_areas) + return false; + + for (i = 0; i < nr_areas; i++) { + struct kho_scratch *area = &kho_scratch[i]; + struct mem_vector region = { + .start = area->addr, + .size = area->size, + }; + + if (process_mem_region(®ion, minimum, image_size)) + break; + } + + return true; +} + +static unsigned long find_random_phys_addr(unsigned long minimum, + unsigned long image_size) +{ + u64 phys_addr; + + /* Bail out early if it's impossible to succeed. */ + if (minimum + image_size > mem_limit) + return 0; + + /* Check if we had too many memmaps. */ + if (memmap_too_large) { + debug_putstr("Aborted memory entries scan (more than 4 memmap= args)!\n"); + return 0; + } + + /* + * During kexec handover only process KHO scratch areas that are known + * not to contain any data that must be preserved. + */ + if (!process_kho_entries(minimum, image_size) && + !process_efi_entries(minimum, image_size)) + process_e820_entries(minimum, image_size); + + phys_addr = slots_fetch_random(); + + /* Perform a final check to make sure the address is in range. */ + if (phys_addr < minimum || phys_addr + image_size > mem_limit) { + warn("Invalid physical address chosen!\n"); + return 0; + } + + return (unsigned long)phys_addr; +} + +static unsigned long find_random_virt_addr(unsigned long minimum, + unsigned long image_size) +{ + unsigned long slots, random_addr; + + /* + * There are how many CONFIG_PHYSICAL_ALIGN-sized slots + * that can hold image_size within the range of minimum to + * KERNEL_IMAGE_SIZE? + */ + slots = 1 + (KERNEL_IMAGE_SIZE - minimum - image_size) / CONFIG_PHYSICAL_ALIGN; + + random_addr = kaslr_get_random_long("Virtual") % slots; + + return random_addr * CONFIG_PHYSICAL_ALIGN + minimum; +} + +/* + * Since this function examines addresses much more numerically, + * it takes the input and output pointers as 'unsigned long'. + */ +void choose_random_location(unsigned long input, + unsigned long input_size, + unsigned long *output, + unsigned long output_size, + unsigned long *virt_addr) +{ + unsigned long random_addr, min_addr; + + if (cmdline_find_option_bool("nokaslr")) { + warn("KASLR disabled: 'nokaslr' on cmdline."); + return; + } + + boot_params_ptr->hdr.loadflags |= KASLR_FLAG; + + if (IS_ENABLED(CONFIG_X86_32)) + mem_limit = KERNEL_IMAGE_SIZE; + else + mem_limit = MAXMEM; + + /* Record the various known unsafe memory ranges. */ + mem_avoid_init(input, input_size, *output); + + /* + * Low end of the randomization range should be the + * smaller of 512M or the initial kernel image + * location: + */ + min_addr = min(*output, 512UL << 20); + /* Make sure minimum is aligned. */ + min_addr = ALIGN(min_addr, CONFIG_PHYSICAL_ALIGN); + + /* Walk available memory entries to find a random address. */ + random_addr = find_random_phys_addr(min_addr, output_size); + if (!random_addr) { + warn("Physical KASLR disabled: no suitable memory region!"); + } else { + /* Update the new physical address location. */ + if (*output != random_addr) + *output = random_addr; + } + + + /* Pick random virtual address starting from LOAD_PHYSICAL_ADDR. */ + if (IS_ENABLED(CONFIG_X86_64)) + random_addr = find_random_virt_addr(LOAD_PHYSICAL_ADDR, output_size); + *virt_addr = random_addr; +} diff --git a/arch/x86/boot/compressed/kernel_info.S b/arch/x86/boot/compressed/kernel_info.S new file mode 100644 index 000000000..f818ee8fb --- /dev/null +++ b/arch/x86/boot/compressed/kernel_info.S @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <asm/bootparam.h> + + .section ".rodata.kernel_info", "a" + + .global kernel_info + +kernel_info: + /* Header, Linux top (structure). */ + .ascii "LToP" + /* Size. */ + .long kernel_info_var_len_data - kernel_info + /* Size total. */ + .long kernel_info_end - kernel_info + + /* Maximal allowed type for setup_data and setup_indirect structs. */ + .long SETUP_TYPE_MAX + +kernel_info_var_len_data: + /* Empty for time being... */ +kernel_info_end: diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c new file mode 100644 index 000000000..0e9f84ab4 --- /dev/null +++ b/arch/x86/boot/compressed/mem.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include "error.h" +#include "misc.h" +#include "tdx.h" +#include "sev.h" +#include <asm/shared/tdx.h> + +/* + * accept_memory() and process_unaccepted_memory() called from EFI stub which + * runs before decompressor and its early_tdx_detect(). + * + * Enumerate TDX directly from the early users. + */ +static bool early_is_tdx_guest(void) +{ + static bool once; + static bool is_tdx; + + if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST)) + return false; + + if (!once) { + u32 eax, sig[3]; + + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, + &sig[0], &sig[2], &sig[1]); + is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig)); + once = true; + } + + return is_tdx; +} + +void arch_accept_memory(phys_addr_t start, phys_addr_t end) +{ + /* Platform-specific memory-acceptance call goes here */ + if (early_is_tdx_guest()) { + if (!tdx_accept_memory(start, end)) + panic("TDX: Failed to accept memory\n"); + } else if (early_is_sevsnp_guest()) { + snp_accept_memory(start, end); + } else { + error("Cannot accept memory: unknown platform\n"); + } +} + +bool init_unaccepted_memory(void) +{ + guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID; + struct efi_unaccepted_memory *table; + unsigned long cfg_table_pa; + unsigned int cfg_table_len; + enum efi_type et; + int ret; + + et = efi_get_type(boot_params_ptr); + if (et == EFI_TYPE_NONE) + return false; + + ret = efi_get_conf_table(boot_params_ptr, &cfg_table_pa, &cfg_table_len); + if (ret) { + warn("EFI config table not found."); + return false; + } + + table = (void *)efi_find_vendor_table(boot_params_ptr, cfg_table_pa, + cfg_table_len, guid); + if (!table) + return false; + + if (table->version != 1) + error("Unknown version of unaccepted memory table\n"); + + /* + * In many cases unaccepted_table is already set by EFI stub, but it + * has to be initialized again to cover cases when the table is not + * allocated by EFI stub or EFI stub copied the kernel image with + * efi_relocate_kernel() before the variable is set. + * + * It must be initialized before the first usage of accept_memory(). + */ + unaccepted_table = table; + + return true; +} diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S new file mode 100644 index 000000000..32f7cc8a8 --- /dev/null +++ b/arch/x86/boot/compressed/mem_encrypt.S @@ -0,0 +1,324 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2017 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lendacky@amd.com> + */ + +#include <linux/linkage.h> + +#include <asm/processor-flags.h> +#include <asm/msr.h> +#include <asm/asm-offsets.h> +#include <asm/segment.h> +#include <asm/trapnr.h> + + .text + .code32 +SYM_FUNC_START(get_sev_encryption_bit) + push %ebx + + movl $0x80000000, %eax /* CPUID to check the highest leaf */ + cpuid + cmpl $0x8000001f, %eax /* See if 0x8000001f is available */ + jb .Lno_sev + + /* + * Check for the SEV feature: + * CPUID Fn8000_001F[EAX] - Bit 1 + * CPUID Fn8000_001F[EBX] - Bits 5:0 + * Pagetable bit position used to indicate encryption + */ + movl $0x8000001f, %eax + cpuid + bt $1, %eax /* Check if SEV is available */ + jnc .Lno_sev + + movl $MSR_AMD64_SEV, %ecx /* Read the SEV MSR */ + rdmsr + bt $MSR_AMD64_SEV_ENABLED_BIT, %eax /* Check if SEV is active */ + jnc .Lno_sev + + movl %ebx, %eax + andl $0x3f, %eax /* Return the encryption bit location */ + jmp .Lsev_exit + +.Lno_sev: + xor %eax, %eax + +.Lsev_exit: + pop %ebx + RET +SYM_FUNC_END(get_sev_encryption_bit) + +/** + * sev_es_req_cpuid - Request a CPUID value from the Hypervisor using + * the GHCB MSR protocol + * + * @%eax: Register to request (0=EAX, 1=EBX, 2=ECX, 3=EDX) + * @%edx: CPUID Function + * + * Returns 0 in %eax on success, non-zero on failure + * %edx returns CPUID value on success + */ +SYM_CODE_START_LOCAL(sev_es_req_cpuid) + shll $30, %eax + orl $0x00000004, %eax + movl $MSR_AMD64_SEV_ES_GHCB, %ecx + wrmsr + rep; vmmcall # VMGEXIT + rdmsr + + /* Check response */ + movl %eax, %ecx + andl $0x3ffff000, %ecx # Bits [12-29] MBZ + jnz 2f + + /* Check return code */ + andl $0xfff, %eax + cmpl $5, %eax + jne 2f + + /* All good - return success */ + xorl %eax, %eax +1: + RET +2: + movl $-1, %eax + jmp 1b +SYM_CODE_END(sev_es_req_cpuid) + +SYM_CODE_START_LOCAL(startup32_vc_handler) + pushl %eax + pushl %ebx + pushl %ecx + pushl %edx + + /* Keep CPUID function in %ebx */ + movl %eax, %ebx + + /* Check if error-code == SVM_EXIT_CPUID */ + cmpl $0x72, 16(%esp) + jne .Lfail + + movl $0, %eax # Request CPUID[fn].EAX + movl %ebx, %edx # CPUID fn + call sev_es_req_cpuid # Call helper + testl %eax, %eax # Check return code + jnz .Lfail + movl %edx, 12(%esp) # Store result + + movl $1, %eax # Request CPUID[fn].EBX + movl %ebx, %edx # CPUID fn + call sev_es_req_cpuid # Call helper + testl %eax, %eax # Check return code + jnz .Lfail + movl %edx, 8(%esp) # Store result + + movl $2, %eax # Request CPUID[fn].ECX + movl %ebx, %edx # CPUID fn + call sev_es_req_cpuid # Call helper + testl %eax, %eax # Check return code + jnz .Lfail + movl %edx, 4(%esp) # Store result + + movl $3, %eax # Request CPUID[fn].EDX + movl %ebx, %edx # CPUID fn + call sev_es_req_cpuid # Call helper + testl %eax, %eax # Check return code + jnz .Lfail + movl %edx, 0(%esp) # Store result + + /* + * Sanity check CPUID results from the Hypervisor. See comment in + * do_vc_no_ghcb() for more details on why this is necessary. + */ + + /* Fail if SEV leaf not available in CPUID[0x80000000].EAX */ + cmpl $0x80000000, %ebx + jne .Lcheck_sev + cmpl $0x8000001f, 12(%esp) + jb .Lfail + jmp .Ldone + +.Lcheck_sev: + /* Fail if SEV bit not set in CPUID[0x8000001f].EAX[1] */ + cmpl $0x8000001f, %ebx + jne .Ldone + btl $1, 12(%esp) + jnc .Lfail + +.Ldone: + popl %edx + popl %ecx + popl %ebx + popl %eax + + /* Remove error code */ + addl $4, %esp + + /* Jump over CPUID instruction */ + addl $2, (%esp) + + iret +.Lfail: + /* Send terminate request to Hypervisor */ + movl $0x100, %eax + xorl %edx, %edx + movl $MSR_AMD64_SEV_ES_GHCB, %ecx + wrmsr + rep; vmmcall + + /* If request fails, go to hlt loop */ + hlt + jmp .Lfail +SYM_CODE_END(startup32_vc_handler) + +/* + * Write an IDT entry into boot32_idt + * + * Parameters: + * + * %eax: Handler address + * %edx: Vector number + * %ecx: IDT address + */ +SYM_FUNC_START_LOCAL(startup32_set_idt_entry) + /* IDT entry address to %ecx */ + leal (%ecx, %edx, 8), %ecx + + /* Build IDT entry, lower 4 bytes */ + movl %eax, %edx + andl $0x0000ffff, %edx # Target code segment offset [15:0] + orl $(__KERNEL32_CS << 16), %edx # Target code segment selector + + /* Store lower 4 bytes to IDT */ + movl %edx, (%ecx) + + /* Build IDT entry, upper 4 bytes */ + movl %eax, %edx + andl $0xffff0000, %edx # Target code segment offset [31:16] + orl $0x00008e00, %edx # Present, Type 32-bit Interrupt Gate + + /* Store upper 4 bytes to IDT */ + movl %edx, 4(%ecx) + + RET +SYM_FUNC_END(startup32_set_idt_entry) + +SYM_FUNC_START(startup32_load_idt) + push %ebp + push %ebx + + call 1f +1: pop %ebp + + leal (boot32_idt - 1b)(%ebp), %ebx + + /* #VC handler */ + leal (startup32_vc_handler - 1b)(%ebp), %eax + movl $X86_TRAP_VC, %edx + movl %ebx, %ecx + call startup32_set_idt_entry + + /* Load IDT */ + leal (boot32_idt_desc - 1b)(%ebp), %ecx + movl %ebx, 2(%ecx) + lidt (%ecx) + + pop %ebx + pop %ebp + RET +SYM_FUNC_END(startup32_load_idt) + +/* + * Check for the correct C-bit position when the startup_32 boot-path is used. + * + * The check makes use of the fact that all memory is encrypted when paging is + * disabled. The function creates 64 bits of random data using the RDRAND + * instruction. RDRAND is mandatory for SEV guests, so always available. If the + * hypervisor violates that the kernel will crash right here. + * + * The 64 bits of random data are stored to a memory location and at the same + * time kept in the %eax and %ebx registers. Since encryption is always active + * when paging is off the random data will be stored encrypted in main memory. + * + * Then paging is enabled. When the C-bit position is correct all memory is + * still mapped encrypted and comparing the register values with memory will + * succeed. An incorrect C-bit position will map all memory unencrypted, so that + * the compare will use the encrypted random data and fail. + */ +SYM_FUNC_START(startup32_check_sev_cbit) + pushl %ebx + pushl %ebp + + call 0f +0: popl %ebp + + /* Check for non-zero sev_status */ + movl (sev_status - 0b)(%ebp), %eax + testl %eax, %eax + jz 4f + + /* + * Get two 32-bit random values - Don't bail out if RDRAND fails + * because it is better to prevent forward progress if no random value + * can be gathered. + */ +1: rdrand %eax + jnc 1b +2: rdrand %ebx + jnc 2b + + /* Store to memory and keep it in the registers */ + leal (sev_check_data - 0b)(%ebp), %ebp + movl %eax, 0(%ebp) + movl %ebx, 4(%ebp) + + /* Enable paging to see if encryption is active */ + movl %cr0, %edx /* Backup %cr0 in %edx */ + movl $(X86_CR0_PG | X86_CR0_PE), %ecx /* Enable Paging and Protected mode */ + movl %ecx, %cr0 + + cmpl %eax, 0(%ebp) + jne 3f + cmpl %ebx, 4(%ebp) + jne 3f + + movl %edx, %cr0 /* Restore previous %cr0 */ + + jmp 4f + +3: /* Check failed - hlt the machine */ + hlt + jmp 3b + +4: + popl %ebp + popl %ebx + RET +SYM_FUNC_END(startup32_check_sev_cbit) + + .code64 + +#include "../../kernel/sev_verify_cbit.S" + + .data + + .balign 8 +SYM_DATA(sme_me_mask, .quad 0) +SYM_DATA(sev_status, .quad 0) +SYM_DATA(sev_check_data, .quad 0) + +SYM_DATA_START_LOCAL(boot32_idt) + .rept 32 + .quad 0 + .endr +SYM_DATA_END(boot32_idt) + +SYM_DATA_START_LOCAL(boot32_idt_desc) + .word . - boot32_idt - 1 + .long 0 +SYM_DATA_END(boot32_idt_desc) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c new file mode 100644 index 000000000..0f41ca0e5 --- /dev/null +++ b/arch/x86/boot/compressed/misc.c @@ -0,0 +1,537 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * misc.c + * + * This is a collection of several routines used to extract the kernel + * which includes KASLR relocation, decompression, ELF parsing, and + * relocation processing. Additionally included are the screen and serial + * output functions and related debugging support functions. + * + * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994 + * puts by Nick Holloway 1993, better puts by Martin Mares 1995 + * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 + */ + +#include "misc.h" +#include "error.h" +#include "../string.h" +#include "../voffset.h" +#include <asm/bootparam_utils.h> + +/* + * WARNING!! + * This code is compiled with -fPIC and it is relocated dynamically at + * run time, but no relocation processing is performed. This means that + * it is not safe to place pointers in static structures. + */ + +/* Macros used by the included decompressor code below. */ +#define STATIC static +/* Define an externally visible malloc()/free(). */ +#define MALLOC_VISIBLE +#include <linux/decompress/mm.h> + +/* + * Provide definitions of memzero and memmove as some of the decompressors will + * try to define their own functions if these are not defined as macros. + */ +#define memzero(s, n) memset((s), 0, (n)) +#ifndef memmove +#define memmove memmove +/* Functions used by the included decompressor code below. */ +void *memmove(void *dest, const void *src, size_t n); +#endif + +/* + * This is set up by the setup-routine at boot-time + */ +struct boot_params *boot_params_ptr; + +struct port_io_ops pio_ops; + +memptr free_mem_ptr; +memptr free_mem_end_ptr; +int spurious_nmi_count; + +static char *vidmem; +static int vidport; + +/* These might be accessed before .bss is cleared, so use .data instead. */ +static int lines __section(".data"); +static int cols __section(".data"); + +#ifdef CONFIG_KERNEL_GZIP +#include "../../../../lib/decompress_inflate.c" +#endif + +#ifdef CONFIG_KERNEL_BZIP2 +#include "../../../../lib/decompress_bunzip2.c" +#endif + +#ifdef CONFIG_KERNEL_LZMA +#include "../../../../lib/decompress_unlzma.c" +#endif + +#ifdef CONFIG_KERNEL_XZ +#include "../../../../lib/decompress_unxz.c" +#endif + +#ifdef CONFIG_KERNEL_LZO +#include "../../../../lib/decompress_unlzo.c" +#endif + +#ifdef CONFIG_KERNEL_LZ4 +#include "../../../../lib/decompress_unlz4.c" +#endif + +#ifdef CONFIG_KERNEL_ZSTD +#include "../../../../lib/decompress_unzstd.c" +#endif +/* + * NOTE: When adding a new decompressor, please update the analysis in + * ../header.S. + */ + +static void scroll(void) +{ + int i; + + memmove(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2); + for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2) + vidmem[i] = ' '; +} + +#define XMTRDY 0x20 + +#define TXR 0 /* Transmit register (WRITE) */ +#define LSR 5 /* Line Status */ +static void serial_putchar(int ch) +{ + unsigned timeout = 0xffff; + + while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout) + cpu_relax(); + + outb(ch, early_serial_base + TXR); +} + +void __putstr(const char *s) +{ + int x, y, pos; + char c; + + if (early_serial_base) { + const char *str = s; + while (*str) { + if (*str == '\n') + serial_putchar('\r'); + serial_putchar(*str++); + } + } + + if (lines == 0 || cols == 0) + return; + + x = boot_params_ptr->screen_info.orig_x; + y = boot_params_ptr->screen_info.orig_y; + + while ((c = *s++) != '\0') { + if (c == '\n') { + x = 0; + if (++y >= lines) { + scroll(); + y--; + } + } else { + vidmem[(x + cols * y) * 2] = c; + if (++x >= cols) { + x = 0; + if (++y >= lines) { + scroll(); + y--; + } + } + } + } + + boot_params_ptr->screen_info.orig_x = x; + boot_params_ptr->screen_info.orig_y = y; + + pos = (x + cols * y) * 2; /* Update cursor position */ + outb(14, vidport); + outb(0xff & (pos >> 9), vidport+1); + outb(15, vidport); + outb(0xff & (pos >> 1), vidport+1); +} + +static noinline void __putnum(unsigned long value, unsigned int base, + int mindig) +{ + char buf[8*sizeof(value)+1]; + char *p; + + p = buf + sizeof(buf); + *--p = '\0'; + + while (mindig-- > 0 || value) { + unsigned char digit = value % base; + digit += (digit >= 10) ? ('a'-10) : '0'; + *--p = digit; + + value /= base; + } + + __putstr(p); +} + +void __puthex(unsigned long value) +{ + __putnum(value, 16, sizeof(value)*2); +} + +void __putdec(unsigned long value) +{ + __putnum(value, 10, 1); +} + +#ifdef CONFIG_X86_NEED_RELOCS +static void handle_relocations(void *output, unsigned long output_len, + unsigned long virt_addr) +{ + int *reloc; + unsigned long delta, map, ptr; + unsigned long min_addr = (unsigned long)output; + unsigned long max_addr = min_addr + (VO___bss_start - VO__text); + + /* + * Calculate the delta between where vmlinux was linked to load + * and where it was actually loaded. + */ + delta = min_addr - LOAD_PHYSICAL_ADDR; + + /* + * The kernel contains a table of relocation addresses. Those + * addresses have the final load address of the kernel in virtual + * memory. We are currently working in the self map. So we need to + * create an adjustment for kernel memory addresses to the self map. + * This will involve subtracting out the base address of the kernel. + */ + map = delta - __START_KERNEL_map; + + /* + * 32-bit always performs relocations. 64-bit relocations are only + * needed if KASLR has chosen a different starting address offset + * from __START_KERNEL_map. + */ + if (IS_ENABLED(CONFIG_X86_64)) + delta = virt_addr - LOAD_PHYSICAL_ADDR; + + if (!delta) { + debug_putstr("No relocation needed... "); + return; + } + debug_putstr("Performing relocations... "); + + /* + * Process relocations: 32 bit relocations first then 64 bit after. + * Two sets of binary relocations are added to the end of the kernel + * before compression. Each relocation table entry is the kernel + * address of the location which needs to be updated stored as a + * 32-bit value which is sign extended to 64 bits. + * + * Format is: + * + * kernel bits... + * 0 - zero terminator for 64 bit relocations + * 64 bit relocation repeated + * 0 - zero terminator for 32 bit relocations + * 32 bit relocation repeated + * + * So we work backwards from the end of the decompressed image. + */ + for (reloc = output + output_len - sizeof(*reloc); *reloc; reloc--) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("32-bit relocation outside of kernel!\n"); + + *(uint32_t *)ptr += delta; + } +#ifdef CONFIG_X86_64 + for (reloc--; *reloc; reloc--) { + long extended = *reloc; + extended += map; + + ptr = (unsigned long)extended; + if (ptr < min_addr || ptr > max_addr) + error("64-bit relocation outside of kernel!\n"); + + *(uint64_t *)ptr += delta; + } +#endif +} +#else +static inline void handle_relocations(void *output, unsigned long output_len, + unsigned long virt_addr) +{ } +#endif + +static size_t parse_elf(void *output) +{ +#ifdef CONFIG_X86_64 + Elf64_Ehdr ehdr; + Elf64_Phdr *phdrs, *phdr; +#else + Elf32_Ehdr ehdr; + Elf32_Phdr *phdrs, *phdr; +#endif + void *dest; + int i; + + memcpy(&ehdr, output, sizeof(ehdr)); + if (ehdr.e_ident[EI_MAG0] != ELFMAG0 || + ehdr.e_ident[EI_MAG1] != ELFMAG1 || + ehdr.e_ident[EI_MAG2] != ELFMAG2 || + ehdr.e_ident[EI_MAG3] != ELFMAG3) + error("Kernel is not a valid ELF file"); + + debug_putstr("Parsing ELF... "); + + phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum); + if (!phdrs) + error("Failed to allocate space for phdrs"); + + memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum); + + for (i = 0; i < ehdr.e_phnum; i++) { + phdr = &phdrs[i]; + + switch (phdr->p_type) { + case PT_LOAD: +#ifdef CONFIG_X86_64 + if ((phdr->p_align % 0x200000) != 0) + error("Alignment of LOAD segment isn't multiple of 2MB"); +#endif +#ifdef CONFIG_RELOCATABLE + dest = output; + dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR); +#else + dest = (void *)(phdr->p_paddr); +#endif + memmove(dest, output + phdr->p_offset, phdr->p_filesz); + break; + default: /* Ignore other PT_* */ break; + } + } + + free(phdrs); + + return ehdr.e_entry - LOAD_PHYSICAL_ADDR; +} + +const unsigned long kernel_text_size = VO___start_rodata - VO__text; +const unsigned long kernel_inittext_offset = VO__sinittext - VO__text; +const unsigned long kernel_inittext_size = VO___inittext_end - VO__sinittext; +const unsigned long kernel_total_size = VO__end - VO__text; + +static u8 boot_heap[BOOT_HEAP_SIZE] __aligned(4); + +extern unsigned char input_data[]; +extern unsigned int input_len, output_len; + +unsigned long decompress_kernel(unsigned char *outbuf, unsigned long virt_addr, + void (*error)(char *x)) +{ + unsigned long entry; + + if (!free_mem_ptr) { + free_mem_ptr = (unsigned long)boot_heap; + free_mem_end_ptr = (unsigned long)boot_heap + sizeof(boot_heap); + } + + if (__decompress(input_data, input_len, NULL, NULL, outbuf, output_len, + NULL, error) < 0) + return ULONG_MAX; + + entry = parse_elf(outbuf); + handle_relocations(outbuf, output_len, virt_addr); + + return entry; +} + +/* + * Set the memory encryption xloadflag based on the mem_encrypt= command line + * parameter, if provided. + */ +static void parse_mem_encrypt(struct setup_header *hdr) +{ + int on = cmdline_find_option_bool("mem_encrypt=on"); + int off = cmdline_find_option_bool("mem_encrypt=off"); + + if (on > off) + hdr->xloadflags |= XLF_MEM_ENCRYPTION; +} + +static void early_sev_detect(void) +{ + /* + * Accessing video memory causes guest termination because + * the boot stage2 #VC handler of SEV-ES/SNP guests does not + * support MMIO handling and kexec -c adds screen_info to the + * boot parameters passed to the kexec kernel, which causes + * console output to be dumped to both video and serial. + */ + if (sev_status & MSR_AMD64_SEV_ES_ENABLED) + lines = cols = 0; +} + +/* + * The compressed kernel image (ZO), has been moved so that its position + * is against the end of the buffer used to hold the uncompressed kernel + * image (VO) and the execution environment (.bss, .brk), which makes sure + * there is room to do the in-place decompression. (See header.S for the + * calculations.) + * + * |-----compressed kernel image------| + * V V + * 0 extract_offset +INIT_SIZE + * |-----------|---------------|-------------------------|--------| + * | | | | + * VO__text startup_32 of ZO VO__end ZO__end + * ^ ^ + * |-------uncompressed kernel image---------| + * + */ +asmlinkage __visible void *extract_kernel(void *rmode, unsigned char *output) +{ + unsigned long virt_addr = LOAD_PHYSICAL_ADDR; + memptr heap = (memptr)boot_heap; + unsigned long needed_size; + size_t entry_offset; + + /* Retain x86 boot parameters pointer passed from startup_32/64. */ + boot_params_ptr = rmode; + + /* Clear flags intended for solely in-kernel use. */ + boot_params_ptr->hdr.loadflags &= ~KASLR_FLAG; + + parse_mem_encrypt(&boot_params_ptr->hdr); + + sanitize_boot_params(boot_params_ptr); + + if (boot_params_ptr->screen_info.orig_video_mode == 7) { + vidmem = (char *) 0xb0000; + vidport = 0x3b4; + } else { + vidmem = (char *) 0xb8000; + vidport = 0x3d4; + } + + lines = boot_params_ptr->screen_info.orig_video_lines; + cols = boot_params_ptr->screen_info.orig_video_cols; + + init_default_io_ops(); + + /* + * Detect TDX guest environment. + * + * It has to be done before console_init() in order to use + * paravirtualized port I/O operations if needed. + */ + early_tdx_detect(); + + early_sev_detect(); + + console_init(); + + /* + * Save RSDP address for later use. Have this after console_init() + * so that early debugging output from the RSDP parsing code can be + * collected. + */ + boot_params_ptr->acpi_rsdp_addr = get_rsdp_addr(); + + debug_putstr("early console in extract_kernel\n"); + + free_mem_ptr = heap; /* Heap */ + free_mem_end_ptr = heap + BOOT_HEAP_SIZE; + + /* + * The memory hole needed for the kernel is the larger of either + * the entire decompressed kernel plus relocation table, or the + * entire decompressed kernel plus .bss and .brk sections. + * + * On X86_64, the memory is mapped with PMD pages. Round the + * size up so that the full extent of PMD pages mapped is + * included in the check against the valid memory table + * entries. This ensures the full mapped area is usable RAM + * and doesn't include any reserved areas. + */ + needed_size = max_t(unsigned long, output_len, kernel_total_size); +#ifdef CONFIG_X86_64 + needed_size = ALIGN(needed_size, MIN_KERNEL_ALIGN); +#endif + + /* Report initial kernel position details. */ + debug_putaddr(input_data); + debug_putaddr(input_len); + debug_putaddr(output); + debug_putaddr(output_len); + debug_putaddr(kernel_total_size); + debug_putaddr(needed_size); + +#ifdef CONFIG_X86_64 + /* Report address of 32-bit trampoline */ + debug_putaddr(trampoline_32bit); +#endif + + choose_random_location((unsigned long)input_data, input_len, + (unsigned long *)&output, + needed_size, + &virt_addr); + + /* Validate memory location choices. */ + if ((unsigned long)output & (MIN_KERNEL_ALIGN - 1)) + error("Destination physical address inappropriately aligned"); + if (virt_addr & (MIN_KERNEL_ALIGN - 1)) + error("Destination virtual address inappropriately aligned"); +#ifdef CONFIG_X86_64 + if (heap > 0x3fffffffffffUL) + error("Destination address too large"); + if (virt_addr + needed_size > KERNEL_IMAGE_SIZE) + error("Destination virtual address is beyond the kernel mapping area"); +#else + if (heap > ((-__PAGE_OFFSET-(128<<20)-1) & 0x7fffffff)) + error("Destination address too large"); +#endif +#ifndef CONFIG_RELOCATABLE + if (virt_addr != LOAD_PHYSICAL_ADDR) + error("Destination virtual address changed when not relocatable"); +#endif + + debug_putstr("\nDecompressing Linux... "); + + if (init_unaccepted_memory()) { + debug_putstr("Accepting memory... "); + accept_memory(__pa(output), needed_size); + } + + entry_offset = decompress_kernel(output, virt_addr, error); + + debug_putstr("done.\nBooting the kernel (entry_offset: 0x"); + debug_puthex(entry_offset); + debug_putstr(").\n"); + + /* Disable exception handling before booting the kernel */ + cleanup_exception_handling(); + + if (spurious_nmi_count) { + error_putstr("Spurious early NMIs ignored: "); + error_putdec(spurious_nmi_count); + error_putstr("\n"); + } + + return output + entry_offset; +} diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h new file mode 100644 index 000000000..4f86c5903 --- /dev/null +++ b/arch/x86/boot/compressed/misc.h @@ -0,0 +1,259 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_COMPRESSED_MISC_H +#define BOOT_COMPRESSED_MISC_H + +/* + * Special hack: we have to be careful, because no indirections are allowed here, + * and paravirt_ops is a kind of one. As it will only run in baremetal anyway, + * we just keep it from happening. (This list needs to be extended when new + * paravirt and debugging variants are added.) + */ +#undef CONFIG_PARAVIRT +#undef CONFIG_PARAVIRT_XXL +#undef CONFIG_PARAVIRT_SPINLOCKS +#undef CONFIG_ARCH_HAS_LAZY_MMU_MODE +#undef CONFIG_KASAN +#undef CONFIG_KASAN_GENERIC + +#define __NO_FORTIFY + +/* cpu_feature_enabled() cannot be used this early */ +#define USE_EARLY_PGTABLE_L5 + +/* + * Boot stub deals with identity mappings, physical and virtual addresses are + * the same, so override these defines. + * + * <asm/page.h> will not define them if they are already defined. + */ +#define __pa(x) ((unsigned long)(x)) +#define __va(x) ((void *)((unsigned long)(x))) + +#include <linux/linkage.h> +#include <linux/screen_info.h> +#include <linux/elf.h> +#include <asm/page.h> +#include <asm/boot.h> +#include <asm/bootparam.h> +#include <asm/desc_defs.h> + +#include "tdx.h" + +#define BOOT_CTYPE_H +#include <linux/acpi.h> + +#define BOOT_BOOT_H +#include "../ctype.h" +#include "../io.h" + +#include "efi.h" + +#ifdef CONFIG_X86_64 +#define memptr long +#else +#define memptr unsigned +#endif + +/* boot/compressed/vmlinux start and end markers */ +extern char _head[], _end[]; + +/* misc.c */ +extern memptr free_mem_ptr; +extern memptr free_mem_end_ptr; +extern int spurious_nmi_count; +void *malloc(int size); +void free(void *where); +void __putstr(const char *s); +void __puthex(unsigned long value); +void __putdec(unsigned long value); +#define error_putstr(__x) __putstr(__x) +#define error_puthex(__x) __puthex(__x) +#define error_putdec(__x) __putdec(__x) + +#ifdef CONFIG_X86_VERBOSE_BOOTUP + +#define debug_putstr(__x) __putstr(__x) +#define debug_puthex(__x) __puthex(__x) +#define debug_putaddr(__x) { \ + debug_putstr(#__x ": 0x"); \ + debug_puthex((unsigned long)(__x)); \ + debug_putstr("\n"); \ + } + +#else + +static inline void debug_putstr(const char *s) +{ } +static inline void debug_puthex(unsigned long value) +{ } +#define debug_putaddr(x) /* */ + +#endif + +/* cmdline.c */ +int cmdline_find_option(const char *option, char *buffer, int bufsize); +int cmdline_find_option_bool(const char *option); + +struct mem_vector { + u64 start; + u64 size; +}; + +#ifdef CONFIG_RANDOMIZE_BASE +/* kaslr.c */ +void choose_random_location(unsigned long input, + unsigned long input_size, + unsigned long *output, + unsigned long output_size, + unsigned long *virt_addr); +#else +static inline void choose_random_location(unsigned long input, + unsigned long input_size, + unsigned long *output, + unsigned long output_size, + unsigned long *virt_addr) +{ +} +#endif + +/* cpuflags.c */ +bool has_cpuflag(int flag); + +#ifdef CONFIG_X86_64 +extern int set_page_decrypted(unsigned long address); +extern int set_page_encrypted(unsigned long address); +extern int set_page_non_present(unsigned long address); +extern unsigned char _pgtable[]; +#endif + +#ifdef CONFIG_EARLY_PRINTK +/* early_serial_console.c */ +extern int early_serial_base; +void console_init(void); +#else +static const int early_serial_base; +static inline void console_init(void) +{ } +#endif + +#ifdef CONFIG_AMD_MEM_ENCRYPT +struct es_em_ctxt; +struct insn; + +void sev_enable(struct boot_params *bp); +void snp_check_features(void); +void sev_es_shutdown_ghcb(void); +extern bool sev_es_check_ghcb_fault(unsigned long address); +void snp_set_page_private(unsigned long paddr); +void snp_set_page_shared(unsigned long paddr); +void sev_prep_identity_maps(unsigned long top_level_pgt); + +enum es_result vc_decode_insn(struct es_em_ctxt *ctxt); +bool insn_has_rep_prefix(struct insn *insn); +void sev_insn_decode_init(void); +bool early_setup_ghcb(void); +#else +static inline void snp_check_features(void) { } +static inline void sev_es_shutdown_ghcb(void) { } +static inline bool sev_es_check_ghcb_fault(unsigned long address) +{ + return false; +} +static inline void snp_set_page_private(unsigned long paddr) { } +static inline void snp_set_page_shared(unsigned long paddr) { } +static inline void sev_prep_identity_maps(unsigned long top_level_pgt) { } +#endif + +/* acpi.c */ +#ifdef CONFIG_ACPI +acpi_physical_address get_rsdp_addr(void); +#else +static inline acpi_physical_address get_rsdp_addr(void) { return 0; } +#endif + +#if defined(CONFIG_RANDOMIZE_BASE) && defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI) +extern struct mem_vector immovable_mem[MAX_NUMNODES*2]; +int count_immovable_mem_regions(void); +#else +static inline int count_immovable_mem_regions(void) { return 0; } +#endif + +/* ident_map_64.c */ +extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d; +extern void kernel_add_identity_map(unsigned long start, unsigned long end); + +/* Used by PAGE_KERN* macros: */ +extern pteval_t __default_kernel_pte_mask; + +/* idt_64.c */ +extern gate_desc boot_idt[BOOT_IDT_ENTRIES]; +extern struct desc_ptr boot_idt_desc; + +#ifdef CONFIG_X86_64 +void cleanup_exception_handling(void); +#else +static inline void cleanup_exception_handling(void) { } +#endif + +/* IDT Entry Points */ +void boot_page_fault(void); +void boot_nmi_trap(void); +void boot_stage1_vc(void); +void boot_stage2_vc(void); + +unsigned long sev_verify_cbit(unsigned long cr3); + +enum efi_type { + EFI_TYPE_64, + EFI_TYPE_32, + EFI_TYPE_NONE, +}; + +#ifdef CONFIG_EFI +/* helpers for early EFI config table access */ +enum efi_type efi_get_type(struct boot_params *bp); +unsigned long efi_get_system_table(struct boot_params *bp); +int efi_get_conf_table(struct boot_params *bp, unsigned long *cfg_tbl_pa, + unsigned int *cfg_tbl_len); +unsigned long efi_find_vendor_table(struct boot_params *bp, + unsigned long cfg_tbl_pa, + unsigned int cfg_tbl_len, + efi_guid_t guid); +#else +static inline enum efi_type efi_get_type(struct boot_params *bp) +{ + return EFI_TYPE_NONE; +} + +static inline unsigned long efi_get_system_table(struct boot_params *bp) +{ + return 0; +} + +static inline int efi_get_conf_table(struct boot_params *bp, + unsigned long *cfg_tbl_pa, + unsigned int *cfg_tbl_len) +{ + return -ENOENT; +} + +static inline unsigned long efi_find_vendor_table(struct boot_params *bp, + unsigned long cfg_tbl_pa, + unsigned int cfg_tbl_len, + efi_guid_t guid) +{ + return 0; +} +#endif /* CONFIG_EFI */ + +#ifdef CONFIG_UNACCEPTED_MEMORY +bool init_unaccepted_memory(void); +#else +static inline bool init_unaccepted_memory(void) { return false; } +#endif + +/* Defined in EFI stub */ +extern struct efi_unaccepted_memory *unaccepted_table; +void accept_memory(phys_addr_t start, unsigned long size); + +#endif /* BOOT_COMPRESSED_MISC_H */ diff --git a/arch/x86/boot/compressed/mkpiggy.c b/arch/x86/boot/compressed/mkpiggy.c new file mode 100644 index 000000000..52aa56cdb --- /dev/null +++ b/arch/x86/boot/compressed/mkpiggy.c @@ -0,0 +1,74 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* ----------------------------------------------------------------------- * + * + * Copyright (C) 2009 Intel Corporation. All rights reserved. + * + * H. Peter Anvin <hpa@linux.intel.com> + * + * ----------------------------------------------------------------------- + * + * Outputs a small assembly wrapper with the appropriate symbols defined. + */ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <inttypes.h> +#include <tools/le_byteshift.h> + +int main(int argc, char *argv[]) +{ + uint32_t olen; + long ilen; + FILE *f = NULL; + int retval = 1; + + if (argc < 2) { + fprintf(stderr, "Usage: %s compressed_file\n", argv[0]); + goto bail; + } + + /* Get the information for the compressed kernel image first */ + + f = fopen(argv[1], "r"); + if (!f) { + perror(argv[1]); + goto bail; + } + + + if (fseek(f, -4L, SEEK_END)) { + perror(argv[1]); + } + + if (fread(&olen, sizeof(olen), 1, f) != 1) { + perror(argv[1]); + goto bail; + } + + ilen = ftell(f); + olen = get_unaligned_le32(&olen); + + printf(".section \".rodata..compressed\",\"a\",@progbits\n"); + printf(".globl z_input_len\n"); + printf("z_input_len = %lu\n", ilen); + printf(".globl z_output_len\n"); + printf("z_output_len = %lu\n", (unsigned long)olen); + + printf(".globl input_data, input_data_end\n"); + printf("input_data:\n"); + printf(".incbin \"%s\"\n", argv[1]); + printf("input_data_end:\n"); + + printf(".section \".rodata\",\"a\",@progbits\n"); + printf(".globl input_len\n"); + printf("input_len:\n\t.long %lu\n", ilen); + printf(".globl output_len\n"); + printf("output_len:\n\t.long %lu\n", (unsigned long)olen); + + retval = 0; +bail: + if (f) + fclose(f); + return retval; +} diff --git a/arch/x86/boot/compressed/pgtable_64.c b/arch/x86/boot/compressed/pgtable_64.c new file mode 100644 index 000000000..1b2fb3570 --- /dev/null +++ b/arch/x86/boot/compressed/pgtable_64.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "misc.h" +#include <asm/bootparam.h> +#include <asm/bootparam_utils.h> +#include <asm/cpuid/api.h> +#include <asm/e820/types.h> +#include <asm/pgtable.h> +#include <asm/processor.h> +#include "../string.h" +#include "efi.h" + +#define BIOS_START_MIN 0x20000U /* 128K, less than this is insane */ +#define BIOS_START_MAX 0x9f000U /* 640K, absolute maximum */ + +/* __pgtable_l5_enabled needs to be in .data to avoid being cleared along with .bss */ +unsigned int __section(".data") __pgtable_l5_enabled; +unsigned int __section(".data") pgdir_shift = 39; +unsigned int __section(".data") ptrs_per_p4d = 1; + +/* Buffer to preserve trampoline memory */ +static char trampoline_save[TRAMPOLINE_32BIT_SIZE]; + +/* + * Trampoline address will be printed by extract_kernel() for debugging + * purposes. + * + * Avoid putting the pointer into .bss as it will be cleared between + * configure_5level_paging() and extract_kernel(). + */ +unsigned long *trampoline_32bit __section(".data"); + +int cmdline_find_option_bool(const char *option); + +static unsigned long find_trampoline_placement(void) +{ + unsigned long bios_start = 0, ebda_start = 0; + struct boot_e820_entry *entry; + char *signature; + int i; + + /* + * Find a suitable spot for the trampoline. + * This code is based on reserve_bios_regions(). + */ + + /* + * EFI systems may not provide legacy ROM. The memory may not be mapped + * at all. + * + * Only look for values in the legacy ROM for non-EFI system. + */ + signature = (char *)&boot_params_ptr->efi_info.efi_loader_signature; + if (strncmp(signature, EFI32_LOADER_SIGNATURE, 4) && + strncmp(signature, EFI64_LOADER_SIGNATURE, 4)) { + ebda_start = *(unsigned short *)0x40e << 4; + bios_start = *(unsigned short *)0x413 << 10; + } + + if (bios_start < BIOS_START_MIN || bios_start > BIOS_START_MAX) + bios_start = BIOS_START_MAX; + + if (ebda_start > BIOS_START_MIN && ebda_start < bios_start) + bios_start = ebda_start; + + bios_start = round_down(bios_start, PAGE_SIZE); + + /* Find the first usable memory region under bios_start. */ + for (i = boot_params_ptr->e820_entries - 1; i >= 0; i--) { + unsigned long new = bios_start; + + entry = &boot_params_ptr->e820_table[i]; + + /* Skip all entries above bios_start. */ + if (bios_start <= entry->addr) + continue; + + /* Skip non-RAM entries. */ + if (entry->type != E820_TYPE_RAM) + continue; + + /* Adjust bios_start to the end of the entry if needed. */ + if (bios_start > entry->addr + entry->size) + new = entry->addr + entry->size; + + /* Keep bios_start page-aligned. */ + new = round_down(new, PAGE_SIZE); + + /* Skip the entry if it's too small. */ + if (new - TRAMPOLINE_32BIT_SIZE < entry->addr) + continue; + + /* Protect against underflow. */ + if (new - TRAMPOLINE_32BIT_SIZE > bios_start) + break; + + bios_start = new; + break; + } + + /* Place the trampoline just below the end of low memory */ + return bios_start - TRAMPOLINE_32BIT_SIZE; +} + +asmlinkage void configure_5level_paging(struct boot_params *bp, void *pgtable) +{ + void (*toggle_la57)(void *cr3); + bool l5_required = false; + + /* Initialize boot_params. Required for cmdline_find_option_bool(). */ + sanitize_boot_params(bp); + boot_params_ptr = bp; + + /* + * Check if LA57 is desired and supported. + * + * There are several parts to the check: + * - if user asked to disable 5-level paging: no5lvl in cmdline + * - if the machine supports 5-level paging: + * + CPUID leaf 7 is supported + * + the leaf has the feature bit set + */ + if (!cmdline_find_option_bool("no5lvl") && + native_cpuid_eax(0) >= 7 && (native_cpuid_ecx(7) & BIT(16))) { + l5_required = true; + + /* Initialize variables for 5-level paging */ + __pgtable_l5_enabled = 1; + pgdir_shift = 48; + ptrs_per_p4d = 512; + } + + /* + * The trampoline will not be used if the paging mode is already set to + * the desired one. + */ + if (l5_required == !!(native_read_cr4() & X86_CR4_LA57)) + return; + + trampoline_32bit = (unsigned long *)find_trampoline_placement(); + + /* Preserve trampoline memory */ + memcpy(trampoline_save, trampoline_32bit, TRAMPOLINE_32BIT_SIZE); + + /* Clear trampoline memory first */ + memset(trampoline_32bit, 0, TRAMPOLINE_32BIT_SIZE); + + /* Copy trampoline code in place */ + toggle_la57 = memcpy(trampoline_32bit + + TRAMPOLINE_32BIT_CODE_OFFSET / sizeof(unsigned long), + &trampoline_32bit_src, TRAMPOLINE_32BIT_CODE_SIZE); + + /* + * Avoid the need for a stack in the 32-bit trampoline code, by using + * LJMP rather than LRET to return back to long mode. LJMP takes an + * immediate absolute address, which needs to be adjusted based on the + * placement of the trampoline. + */ + *(u32 *)((u8 *)toggle_la57 + trampoline_ljmp_imm_offset) += + (unsigned long)toggle_la57; + + /* + * The code below prepares page table in trampoline memory. + * + * The new page table will be used by trampoline code for switching + * from 4- to 5-level paging or vice versa. + */ + + if (l5_required) { + /* + * For 4- to 5-level paging transition, set up current CR3 as + * the first and the only entry in a new top-level page table. + */ + *trampoline_32bit = native_read_cr3_pa() | _PAGE_TABLE_NOENC; + } else { + u64 *new_cr3; + pgd_t *pgdp; + + /* + * For 5- to 4-level paging transition, copy page table pointed + * by first entry in the current top-level page table as our + * new top-level page table. + * + * We cannot just point to the page table from trampoline as it + * may be above 4G. + */ + pgdp = (pgd_t *)native_read_cr3_pa(); + new_cr3 = (u64 *)(native_pgd_val(pgdp[0]) & PTE_PFN_MASK); + memcpy(trampoline_32bit, new_cr3, PAGE_SIZE); + } + + toggle_la57(trampoline_32bit); + + /* + * Move the top level page table out of trampoline memory. + */ + memcpy(pgtable, trampoline_32bit, PAGE_SIZE); + native_write_cr3((unsigned long)pgtable); + + /* Restore trampoline memory */ + memcpy(trampoline_32bit, trampoline_save, TRAMPOLINE_32BIT_SIZE); +} diff --git a/arch/x86/boot/compressed/sbat.S b/arch/x86/boot/compressed/sbat.S new file mode 100644 index 000000000..838f70a99 --- /dev/null +++ b/arch/x86/boot/compressed/sbat.S @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Embed SBAT data in the kernel. + */ + .pushsection ".sbat", "a", @progbits + .incbin CONFIG_EFI_SBAT_FILE + .popsection diff --git a/arch/x86/boot/compressed/sev-handle-vc.c b/arch/x86/boot/compressed/sev-handle-vc.c new file mode 100644 index 000000000..030001b46 --- /dev/null +++ b/arch/x86/boot/compressed/sev-handle-vc.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "misc.h" +#include "error.h" +#include "sev.h" + +#include <linux/kernel.h> +#include <linux/string.h> +#include <asm/insn.h> +#include <asm/pgtable_types.h> +#include <asm/ptrace.h> +#include <asm/sev.h> +#include <asm/trapnr.h> +#include <asm/trap_pf.h> +#include <asm/fpu/xcr.h> + +#define __BOOT_COMPRESSED +#undef __init +#define __init + +/* Basic instruction decoding support needed */ +#include "../../lib/inat.c" +#include "../../lib/insn.c" + +/* + * Copy a version of this function here - insn-eval.c can't be used in + * pre-decompression code. + */ +bool insn_has_rep_prefix(struct insn *insn) +{ + insn_byte_t p; + + insn_get_prefixes(insn); + + for_each_insn_prefix(insn, p) { + if (p == 0xf2 || p == 0xf3) + return true; + } + + return false; +} + +enum es_result vc_decode_insn(struct es_em_ctxt *ctxt) +{ + char buffer[MAX_INSN_SIZE]; + int ret; + + memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE); + + ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64); + if (ret < 0) + return ES_DECODE_FAILED; + + return ES_OK; +} + +extern void sev_insn_decode_init(void) __alias(inat_init_tables); + +/* + * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and + * doesn't use segments. + */ +static unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx) +{ + return 0UL; +} + +static enum es_result vc_write_mem(struct es_em_ctxt *ctxt, + void *dst, char *buf, size_t size) +{ + memcpy(dst, buf, size); + + return ES_OK; +} + +static enum es_result vc_read_mem(struct es_em_ctxt *ctxt, + void *src, char *buf, size_t size) +{ + memcpy(buf, src, size); + + return ES_OK; +} + +static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size) +{ + return ES_OK; +} + +static bool fault_in_kernel_space(unsigned long address) +{ + return false; +} + +#define sev_printk(fmt, ...) + +#include "../../coco/sev/vc-shared.c" + +void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code) +{ + struct es_em_ctxt ctxt; + enum es_result result; + + if (!boot_ghcb && !early_setup_ghcb()) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); + + vc_ghcb_invalidate(boot_ghcb); + result = vc_init_em_ctxt(&ctxt, regs, exit_code); + if (result != ES_OK) + goto finish; + + result = vc_check_opcode_bytes(&ctxt, exit_code); + if (result != ES_OK) + goto finish; + + switch (exit_code) { + case SVM_EXIT_RDTSC: + case SVM_EXIT_RDTSCP: + result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code); + break; + case SVM_EXIT_IOIO: + result = vc_handle_ioio(boot_ghcb, &ctxt); + break; + case SVM_EXIT_CPUID: + result = vc_handle_cpuid(boot_ghcb, &ctxt); + break; + default: + result = ES_UNSUPPORTED; + break; + } + +finish: + if (result == ES_OK) + vc_finish_insn(&ctxt); + else if (result != ES_RETRY) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); +} diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c new file mode 100644 index 000000000..c6512f2ea --- /dev/null +++ b/arch/x86/boot/compressed/sev.c @@ -0,0 +1,513 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AMD Encrypted Register State Support + * + * Author: Joerg Roedel <jroedel@suse.de> + */ + +/* + * misc.h needs to be first because it knows how to include the other kernel + * headers in the pre-decompression code in a way that does not break + * compilation. + */ +#include "misc.h" + +#include <asm/bootparam.h> +#include <asm/pgtable_types.h> +#include <asm/shared/msr.h> +#include <asm/sev.h> +#include <asm/trapnr.h> +#include <asm/trap_pf.h> +#include <asm/msr-index.h> +#include <asm/fpu/xcr.h> +#include <asm/ptrace.h> +#include <asm/svm.h> +#include <asm/cpuid/api.h> + +#include "error.h" +#include "sev.h" + +static struct ghcb boot_ghcb_page __aligned(PAGE_SIZE); +struct ghcb *boot_ghcb __section(".data"); + +#undef __init +#define __init + +#define __BOOT_COMPRESSED + +u8 snp_vmpl __section(".data"); +u16 ghcb_version __section(".data"); + +u64 boot_svsm_caa_pa __section(".data"); + +/* Include code for early handlers */ +#include "../../boot/startup/sev-shared.c" + +static bool sev_snp_enabled(void) +{ + return sev_status & MSR_AMD64_SEV_SNP_ENABLED; +} + +void snp_set_page_private(unsigned long paddr) +{ + struct psc_desc d = { + SNP_PAGE_STATE_PRIVATE, + (struct svsm_ca *)boot_svsm_caa_pa, + boot_svsm_caa_pa + }; + + if (!sev_snp_enabled()) + return; + + __page_state_change(paddr, paddr, &d); +} + +void snp_set_page_shared(unsigned long paddr) +{ + struct psc_desc d = { + SNP_PAGE_STATE_SHARED, + (struct svsm_ca *)boot_svsm_caa_pa, + boot_svsm_caa_pa + }; + + if (!sev_snp_enabled()) + return; + + __page_state_change(paddr, paddr, &d); +} + +bool early_setup_ghcb(void) +{ + if (set_page_decrypted((unsigned long)&boot_ghcb_page)) + return false; + + /* Page is now mapped decrypted, clear it */ + memset(&boot_ghcb_page, 0, sizeof(boot_ghcb_page)); + + boot_ghcb = &boot_ghcb_page; + + /* Initialize lookup tables for the instruction decoder */ + sev_insn_decode_init(); + + /* SNP guest requires the GHCB GPA must be registered */ + if (sev_snp_enabled()) + snp_register_ghcb_early(__pa(&boot_ghcb_page)); + + return true; +} + +void snp_accept_memory(phys_addr_t start, phys_addr_t end) +{ + struct psc_desc d = { + SNP_PAGE_STATE_PRIVATE, + (struct svsm_ca *)boot_svsm_caa_pa, + boot_svsm_caa_pa + }; + + for (phys_addr_t pa = start; pa < end; pa += PAGE_SIZE) + __page_state_change(pa, pa, &d); +} + +void sev_es_shutdown_ghcb(void) +{ + if (!boot_ghcb) + return; + + if (!sev_es_check_cpu_features()) + error("SEV-ES CPU Features missing."); + + /* + * This denotes whether to use the GHCB MSR protocol or the GHCB + * shared page to perform a GHCB request. Since the GHCB page is + * being changed to encrypted, it can't be used to perform GHCB + * requests. Clear the boot_ghcb variable so that the GHCB MSR + * protocol is used to change the GHCB page over to an encrypted + * page. + */ + boot_ghcb = NULL; + + /* + * GHCB Page must be flushed from the cache and mapped encrypted again. + * Otherwise the running kernel will see strange cache effects when + * trying to use that page. + */ + if (set_page_encrypted((unsigned long)&boot_ghcb_page)) + error("Can't map GHCB page encrypted"); + + /* + * GHCB page is mapped encrypted again and flushed from the cache. + * Mark it non-present now to catch bugs when #VC exceptions trigger + * after this point. + */ + if (set_page_non_present((unsigned long)&boot_ghcb_page)) + error("Can't unmap GHCB page"); +} + +static void __noreturn sev_es_ghcb_terminate(struct ghcb *ghcb, unsigned int set, + unsigned int reason, u64 exit_info_2) +{ + u64 exit_info_1 = SVM_VMGEXIT_TERM_REASON(set, reason); + + vc_ghcb_invalidate(ghcb); + ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_TERM_REQUEST); + ghcb_set_sw_exit_info_1(ghcb, exit_info_1); + ghcb_set_sw_exit_info_2(ghcb, exit_info_2); + + sev_es_wr_ghcb_msr(__pa(ghcb)); + VMGEXIT(); + + while (true) + asm volatile("hlt\n" : : : "memory"); +} + +bool sev_es_check_ghcb_fault(unsigned long address) +{ + /* Check whether the fault was on the GHCB page */ + return ((address & PAGE_MASK) == (unsigned long)&boot_ghcb_page); +} + +/* + * SNP_FEATURES_IMPL_REQ is the mask of SNP features that will need + * guest side implementation for proper functioning of the guest. If any + * of these features are enabled in the hypervisor but are lacking guest + * side implementation, the behavior of the guest will be undefined. The + * guest could fail in non-obvious way making it difficult to debug. + * + * As the behavior of reserved feature bits is unknown to be on the + * safe side add them to the required features mask. + */ +#define SNP_FEATURES_IMPL_REQ (MSR_AMD64_SNP_VTOM | \ + MSR_AMD64_SNP_REFLECT_VC | \ + MSR_AMD64_SNP_RESTRICTED_INJ | \ + MSR_AMD64_SNP_ALT_INJ | \ + MSR_AMD64_SNP_DEBUG_SWAP | \ + MSR_AMD64_SNP_VMPL_SSS | \ + MSR_AMD64_SNP_SECURE_TSC | \ + MSR_AMD64_SNP_VMGEXIT_PARAM | \ + MSR_AMD64_SNP_VMSA_REG_PROT | \ + MSR_AMD64_SNP_RESERVED_BIT13 | \ + MSR_AMD64_SNP_RESERVED_BIT15 | \ + MSR_AMD64_SNP_SECURE_AVIC | \ + MSR_AMD64_SNP_RESERVED_BITS19_22 | \ + MSR_AMD64_SNP_RESERVED_MASK) + +#ifdef CONFIG_AMD_SECURE_AVIC +#define SNP_FEATURE_SECURE_AVIC MSR_AMD64_SNP_SECURE_AVIC +#else +#define SNP_FEATURE_SECURE_AVIC 0 +#endif + +/* + * SNP_FEATURES_IMPL is the mask of SNP features that are implemented + * by the guest kernel. As and when a new feature is implemented in the + * guest kernel, a corresponding bit should be added to the mask. + */ +#define SNP_FEATURES_IMPL (MSR_AMD64_SNP_DEBUG_SWAP | \ + MSR_AMD64_SNP_SECURE_TSC | \ + SNP_FEATURE_SECURE_AVIC) + +u64 snp_get_unsupported_features(u64 status) +{ + if (!(status & MSR_AMD64_SEV_SNP_ENABLED)) + return 0; + + return status & SNP_FEATURES_IMPL_REQ & ~SNP_FEATURES_IMPL; +} + +void snp_check_features(void) +{ + u64 unsupported; + + /* + * Terminate the boot if hypervisor has enabled any feature lacking + * guest side implementation. Pass on the unsupported features mask through + * EXIT_INFO_2 of the GHCB protocol so that those features can be reported + * as part of the guest boot failure. + */ + unsupported = snp_get_unsupported_features(sev_status); + if (unsupported) { + if (ghcb_version < 2 || (!boot_ghcb && !early_setup_ghcb())) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + + sev_es_ghcb_terminate(boot_ghcb, SEV_TERM_SET_GEN, + GHCB_SNP_UNSUPPORTED, unsupported); + } +} + +/* Search for Confidential Computing blob in the EFI config table. */ +static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp) +{ + unsigned long cfg_table_pa; + unsigned int cfg_table_len; + int ret; + + ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len); + if (ret) + return NULL; + + return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa, + cfg_table_len, + EFI_CC_BLOB_GUID); +} + +/* + * Initial set up of SNP relies on information provided by the + * Confidential Computing blob, which can be passed to the boot kernel + * by firmware/bootloader in the following ways: + * + * - via an entry in the EFI config table + * - via a setup_data structure, as defined by the Linux Boot Protocol + * + * Scan for the blob in that order. + */ +static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp) +{ + struct cc_blob_sev_info *cc_info; + + cc_info = find_cc_blob_efi(bp); + if (cc_info) + goto found_cc_info; + + cc_info = find_cc_blob_setup_data(bp); + if (!cc_info) + return NULL; + +found_cc_info: + if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + + return cc_info; +} + +/* + * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks + * will verify the SNP CPUID/MSR bits. + */ +static bool early_snp_init(struct boot_params *bp) +{ + struct cc_blob_sev_info *cc_info; + + if (!bp) + return false; + + cc_info = find_cc_blob(bp); + if (!cc_info) + return false; + + /* + * If a SNP-specific Confidential Computing blob is present, then + * firmware/bootloader have indicated SNP support. Verifying this + * involves CPUID checks which will be more reliable if the SNP + * CPUID table is used. See comments over snp_setup_cpuid_table() for + * more details. + */ + setup_cpuid_table(cc_info); + + /* + * Record the SVSM Calling Area (CA) address if the guest is not + * running at VMPL0. The CA will be used to communicate with the + * SVSM and request its services. + */ + svsm_setup_ca(cc_info, rip_rel_ptr(&boot_ghcb_page)); + + /* + * Pass run-time kernel a pointer to CC info via boot_params so EFI + * config table doesn't need to be searched again during early startup + * phase. + */ + bp->cc_blob_address = (u32)(unsigned long)cc_info; + + return true; +} + +/* + * sev_check_cpu_support - Check for SEV support in the CPU capabilities + * + * Returns < 0 if SEV is not supported, otherwise the position of the + * encryption bit in the page table descriptors. + */ +static int sev_check_cpu_support(void) +{ + unsigned int eax, ebx, ecx, edx; + + /* Check for the SME/SEV support leaf */ + eax = 0x80000000; + ecx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + if (eax < 0x8000001f) + return -ENODEV; + + /* + * Check for the SME/SEV feature: + * CPUID Fn8000_001F[EAX] + * - Bit 0 - Secure Memory Encryption support + * - Bit 1 - Secure Encrypted Virtualization support + * CPUID Fn8000_001F[EBX] + * - Bits 5:0 - Pagetable bit position used to indicate encryption + */ + eax = 0x8000001f; + ecx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + /* Check whether SEV is supported */ + if (!(eax & BIT(1))) + return -ENODEV; + + sev_snp_needs_sfw = !(ebx & BIT(31)); + + return ebx & 0x3f; +} + +void sev_enable(struct boot_params *bp) +{ + struct msr m; + int bitpos; + bool snp; + + /* + * bp->cc_blob_address should only be set by boot/compressed kernel. + * Initialize it to 0 to ensure that uninitialized values from + * buggy bootloaders aren't propagated. + */ + if (bp) + bp->cc_blob_address = 0; + + /* + * Do an initial SEV capability check before early_snp_init() which + * loads the CPUID page and the same checks afterwards are done + * without the hypervisor and are trustworthy. + * + * If the HV fakes SEV support, the guest will crash'n'burn + * which is good enough. + */ + + if (sev_check_cpu_support() < 0) + return; + + /* + * Setup/preliminary detection of SNP. This will be sanity-checked + * against CPUID/MSR values later. + */ + snp = early_snp_init(bp); + + /* Now repeat the checks with the SNP CPUID table. */ + + bitpos = sev_check_cpu_support(); + if (bitpos < 0) { + if (snp) + error("SEV-SNP support indicated by CC blob, but not CPUID."); + return; + } + + /* Set the SME mask if this is an SEV guest. */ + raw_rdmsr(MSR_AMD64_SEV, &m); + sev_status = m.q; + if (!(sev_status & MSR_AMD64_SEV_ENABLED)) + return; + + /* Negotiate the GHCB protocol version. */ + if (sev_status & MSR_AMD64_SEV_ES_ENABLED) { + if (!sev_es_negotiate_protocol()) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_PROT_UNSUPPORTED); + } + + /* + * SNP is supported in v2 of the GHCB spec which mandates support for HV + * features. + */ + if (sev_status & MSR_AMD64_SEV_SNP_ENABLED) { + u64 hv_features; + + hv_features = get_hv_features(); + if (!(hv_features & GHCB_HV_FT_SNP)) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + + /* + * Running at VMPL0 is required unless an SVSM is present and + * the hypervisor supports the required SVSM GHCB events. + */ + if (snp_vmpl && !(hv_features & GHCB_HV_FT_SNP_MULTI_VMPL)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NOT_VMPL0); + } + + if (snp && !(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) + error("SEV-SNP supported indicated by CC blob, but not SEV status MSR."); + + sme_me_mask = BIT_ULL(bitpos); +} + +/* + * sev_get_status - Retrieve the SEV status mask + * + * Returns 0 if the CPU is not SEV capable, otherwise the value of the + * AMD64_SEV MSR. + */ +u64 sev_get_status(void) +{ + struct msr m; + + if (sev_check_cpu_support() < 0) + return 0; + + raw_rdmsr(MSR_AMD64_SEV, &m); + return m.q; +} + +void sev_prep_identity_maps(unsigned long top_level_pgt) +{ + /* + * The Confidential Computing blob is used very early in uncompressed + * kernel to find the in-memory CPUID table to handle CPUID + * instructions. Make sure an identity-mapping exists so it can be + * accessed after switchover. + */ + if (sev_snp_enabled()) { + unsigned long cc_info_pa = boot_params_ptr->cc_blob_address; + struct cc_blob_sev_info *cc_info; + + kernel_add_identity_map(cc_info_pa, cc_info_pa + sizeof(*cc_info)); + + cc_info = (struct cc_blob_sev_info *)cc_info_pa; + kernel_add_identity_map(cc_info->cpuid_phys, cc_info->cpuid_phys + cc_info->cpuid_len); + } + + sev_verify_cbit(top_level_pgt); +} + +bool early_is_sevsnp_guest(void) +{ + static bool sevsnp; + + if (sevsnp) + return true; + + if (!(sev_get_status() & MSR_AMD64_SEV_SNP_ENABLED)) + return false; + + sevsnp = true; + + if (!snp_vmpl) { + unsigned int eax, ebx, ecx, edx; + + /* + * CPUID Fn8000_001F_EAX[28] - SVSM support + */ + eax = 0x8000001f; + ecx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + if (eax & BIT(28)) { + struct msr m; + + /* Obtain the address of the calling area to use */ + raw_rdmsr(MSR_SVSM_CAA, &m); + boot_svsm_caa_pa = m.q; + + /* + * The real VMPL level cannot be discovered, but the + * memory acceptance routines make no use of that so + * any non-zero value suffices here. + */ + snp_vmpl = U8_MAX; + } + } + return true; +} diff --git a/arch/x86/boot/compressed/sev.h b/arch/x86/boot/compressed/sev.h new file mode 100644 index 000000000..22637b416 --- /dev/null +++ b/arch/x86/boot/compressed/sev.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * AMD SEV header for early boot related functions. + * + * Author: Tom Lendacky <thomas.lendacky@amd.com> + */ + +#ifndef BOOT_COMPRESSED_SEV_H +#define BOOT_COMPRESSED_SEV_H + +#ifdef CONFIG_AMD_MEM_ENCRYPT + +#include <asm/shared/msr.h> + +void snp_accept_memory(phys_addr_t start, phys_addr_t end); +u64 sev_get_status(void); +bool early_is_sevsnp_guest(void); + +static inline u64 sev_es_rd_ghcb_msr(void) +{ + struct msr m; + + raw_rdmsr(MSR_AMD64_SEV_ES_GHCB, &m); + + return m.q; +} + +static inline void sev_es_wr_ghcb_msr(u64 val) +{ + struct msr m; + + m.q = val; + raw_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m); +} + +#else + +static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { } +static inline u64 sev_get_status(void) { return 0; } +static inline bool early_is_sevsnp_guest(void) { return false; } + +#endif + +#endif diff --git a/arch/x86/boot/compressed/string.c b/arch/x86/boot/compressed/string.c new file mode 100644 index 000000000..9af19d961 --- /dev/null +++ b/arch/x86/boot/compressed/string.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This provides an optimized implementation of memcpy, and a simplified + * implementation of memset and memmove. These are used here because the + * standard kernel runtime versions are not yet available and we don't + * trust the gcc built-in implementations as they may do unexpected things + * (e.g. FPU ops) in the minimal decompression stub execution environment. + */ +#include "error.h" + +#include "../string.c" + +#ifdef CONFIG_X86_32 +static void *____memcpy(void *dest, const void *src, size_t n) +{ + int d0, d1, d2; + asm volatile( + "rep movsl\n\t" + "movl %4,%%ecx\n\t" + "rep movsb" + : "=&c" (d0), "=&D" (d1), "=&S" (d2) + : "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src) + : "memory"); + + return dest; +} +#else +static void *____memcpy(void *dest, const void *src, size_t n) +{ + long d0, d1, d2; + asm volatile( + "rep movsq\n\t" + "movq %4,%%rcx\n\t" + "rep movsb" + : "=&c" (d0), "=&D" (d1), "=&S" (d2) + : "0" (n >> 3), "g" (n & 7), "1" (dest), "2" (src) + : "memory"); + + return dest; +} +#endif + +void *memset(void *s, int c, size_t n) +{ + int i; + char *ss = s; + + for (i = 0; i < n; i++) + ss[i] = c; + return s; +} + +void *memmove(void *dest, const void *src, size_t n) +{ + unsigned char *d = dest; + const unsigned char *s = src; + + if (d <= s || d - s >= n) + return ____memcpy(dest, src, n); + + while (n-- > 0) + d[n] = s[n]; + + return dest; +} + +/* Detect and warn about potential overlaps, but handle them with memmove. */ +void *memcpy(void *dest, const void *src, size_t n) +{ + if (dest > src && dest - src < n) { + warn("Avoiding potentially unsafe overlapping memcpy()!"); + return memmove(dest, src, n); + } + return ____memcpy(dest, src, n); +} + +#ifdef CONFIG_KASAN +extern void *__memset(void *s, int c, size_t n) __alias(memset); +extern void *__memmove(void *dest, const void *src, size_t n) __alias(memmove); +extern void *__memcpy(void *dest, const void *src, size_t n) __alias(memcpy); +#endif diff --git a/arch/x86/boot/compressed/tdcall.S b/arch/x86/boot/compressed/tdcall.S new file mode 100644 index 000000000..46d0495e0 --- /dev/null +++ b/arch/x86/boot/compressed/tdcall.S @@ -0,0 +1,3 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include "../../coco/tdx/tdcall.S" diff --git a/arch/x86/boot/compressed/tdx-shared.c b/arch/x86/boot/compressed/tdx-shared.c new file mode 100644 index 000000000..5ac43762f --- /dev/null +++ b/arch/x86/boot/compressed/tdx-shared.c @@ -0,0 +1,2 @@ +#include "error.h" +#include "../../coco/tdx/tdx-shared.c" diff --git a/arch/x86/boot/compressed/tdx.c b/arch/x86/boot/compressed/tdx.c new file mode 100644 index 000000000..8451d6a10 --- /dev/null +++ b/arch/x86/boot/compressed/tdx.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "../cpuflags.h" +#include "../string.h" +#include "../io.h" +#include "error.h" + +#include <vdso/limits.h> +#include <uapi/asm/vmx.h> + +#include <asm/shared/tdx.h> + +/* Called from __tdx_hypercall() for unrecoverable failure */ +void __tdx_hypercall_failed(void) +{ + error("TDVMCALL failed. TDX module bug?"); +} + +static inline unsigned int tdx_io_in(int size, u16 port) +{ + struct tdx_module_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION), + .r12 = size, + .r13 = 0, + .r14 = port, + }; + + if (__tdx_hypercall(&args)) + return UINT_MAX; + + return args.r11; +} + +static inline void tdx_io_out(int size, u16 port, u32 value) +{ + struct tdx_module_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION), + .r12 = size, + .r13 = 1, + .r14 = port, + .r15 = value, + }; + + __tdx_hypercall(&args); +} + +static inline u8 tdx_inb(u16 port) +{ + return tdx_io_in(1, port); +} + +static inline void tdx_outb(u8 value, u16 port) +{ + tdx_io_out(1, port, value); +} + +static inline void tdx_outw(u16 value, u16 port) +{ + tdx_io_out(2, port, value); +} + +void early_tdx_detect(void) +{ + u32 eax, sig[3]; + + cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2], &sig[1]); + + if (memcmp(TDX_IDENT, sig, sizeof(sig))) + return; + + /* Use hypercalls instead of I/O instructions */ + pio_ops.f_inb = tdx_inb; + pio_ops.f_outb = tdx_outb; + pio_ops.f_outw = tdx_outw; +} diff --git a/arch/x86/boot/compressed/tdx.h b/arch/x86/boot/compressed/tdx.h new file mode 100644 index 000000000..9055482cd --- /dev/null +++ b/arch/x86/boot/compressed/tdx.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_COMPRESSED_TDX_H +#define BOOT_COMPRESSED_TDX_H + +#include <linux/types.h> + +#ifdef CONFIG_INTEL_TDX_GUEST +void early_tdx_detect(void); +#else +static inline void early_tdx_detect(void) { }; +#endif + +#endif /* BOOT_COMPRESSED_TDX_H */ diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S new file mode 100644 index 000000000..e0b152715 --- /dev/null +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -0,0 +1,128 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <asm-generic/vmlinux.lds.h> + +OUTPUT_FORMAT(CONFIG_OUTPUT_FORMAT) + +#undef i386 + +#include <asm/cache.h> +#include <asm/page_types.h> + +#ifdef CONFIG_X86_64 +OUTPUT_ARCH(i386:x86-64) +ENTRY(startup_64) +#else +OUTPUT_ARCH(i386) +ENTRY(startup_32) +#endif + +SECTIONS +{ + /* Be careful parts of head_64.S assume startup_32 is at + * address 0. + */ + . = 0; + .head.text : { + _head = . ; + HEAD_TEXT + _ehead = . ; + } + .rodata..compressed : { + *(.rodata..compressed) + } + .text : { + _text = .; /* Text */ + *(.text) + *(.text.*) + *(.noinstr.text) + _etext = . ; + } + .rodata : { + _rodata = . ; + *(.rodata) /* read-only data */ + *(.rodata.*) + _erodata = . ; + } +#ifdef CONFIG_EFI_SBAT + .sbat : ALIGN(0x1000) { + _sbat = . ; + *(.sbat) + _esbat = ALIGN(0x1000); + . = _esbat; + } +#endif + .data : ALIGN(0x1000) { + _data = . ; + *(.data) + *(.data.*) + + /* Add 4 bytes of extra space for the obsolete CRC-32 checksum */ + . = ALIGN(. + 4, 0x200); + _edata = . ; + } + . = ALIGN(L1_CACHE_BYTES); + .bss : { + _bss = . ; + *(.bss) + *(.bss.*) + *(COMMON) + . = ALIGN(8); /* For convenience during zeroing */ + _ebss = .; + } +#ifdef CONFIG_X86_64 + . = ALIGN(PAGE_SIZE); + .pgtable : { + _pgtable = . ; + *(.pgtable) + _epgtable = . ; + } +#endif + . = ALIGN(PAGE_SIZE); /* keep ZO size page aligned */ + _end = .; + + STABS_DEBUG + DWARF_DEBUG + ELF_DETAILS + + DISCARDS + /DISCARD/ : { + *(.dynamic) *(.dynsym) *(.dynstr) *(.dynbss) + *(.hash) *(.gnu.hash) + *(.note.*) *(.modinfo) + } + + .got.plt (INFO) : { + *(.got.plt) + } + ASSERT(SIZEOF(.got.plt) == 0 || +#ifdef CONFIG_X86_64 + SIZEOF(.got.plt) == 0x18, +#else + SIZEOF(.got.plt) == 0xc, +#endif + "Unexpected GOT/PLT entries detected!") + + /* + * Sections that should stay zero sized, which is safer to + * explicitly check instead of blindly discarding. + */ + .got : { + *(.got) + } + ASSERT(SIZEOF(.got) == 0, "Unexpected GOT entries detected!") + + .plt : { + *(.plt) *(.plt.*) + } + ASSERT(SIZEOF(.plt) == 0, "Unexpected run-time procedure linkages detected!") + + .rel.dyn : { + *(.rel.*) *(.rel_*) + } + ASSERT(SIZEOF(.rel.dyn) == 0, "Unexpected run-time relocations (.rel) detected!") + + .rela.dyn : { + *(.rela.*) *(.rela_*) + } + ASSERT(SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations (.rela) detected!") +} diff --git a/arch/x86/boot/copy.S b/arch/x86/boot/copy.S new file mode 100644 index 000000000..3973a67cd --- /dev/null +++ b/arch/x86/boot/copy.S @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* ----------------------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +#include <linux/linkage.h> + +/* + * Memory copy routines + */ + + .code16 + .text + +SYM_FUNC_START_NOALIGN(memcpy) + pushw %si + pushw %di + movw %ax, %di + movw %dx, %si + pushw %cx + shrw $2, %cx + rep movsl + popw %cx + andw $3, %cx + rep movsb + popw %di + popw %si + retl +SYM_FUNC_END(memcpy) + +SYM_FUNC_START_NOALIGN(memset) + pushw %di + movw %ax, %di + movzbl %dl, %eax + imull $0x01010101,%eax + pushw %cx + shrw $2, %cx + rep stosl + popw %cx + andw $3, %cx + rep stosb + popw %di + retl +SYM_FUNC_END(memset) + +SYM_FUNC_START_NOALIGN(copy_from_fs) + pushw %ds + pushw %fs + popw %ds + calll memcpy + popw %ds + retl +SYM_FUNC_END(copy_from_fs) + +SYM_FUNC_START_NOALIGN(copy_to_fs) + pushw %es + pushw %fs + popw %es + calll memcpy + popw %es + retl +SYM_FUNC_END(copy_to_fs) diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c new file mode 100644 index 000000000..feb6dbd7c --- /dev/null +++ b/arch/x86/boot/cpu.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007-2008 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * arch/x86/boot/cpu.c + * + * Check for obligatory CPU features and abort if the features are not + * present. + */ + +#include "boot.h" +#include "cpustr.h" + +static char *cpu_name(int level) +{ + static char buf[6]; + + if (level == 64) { + return "x86-64"; + } else { + if (level == 15) + level = 6; + sprintf(buf, "i%d86", level); + return buf; + } +} + +static void show_cap_strs(u32 *err_flags) +{ + int i, j; + const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs; + for (i = 0; i < NCAPINTS; i++) { + u32 e = err_flags[i]; + for (j = 0; j < 32; j++) { + if (msg_strs[0] < i || + (msg_strs[0] == i && msg_strs[1] < j)) { + /* Skip to the next string */ + msg_strs += 2; + while (*msg_strs++) + ; + } + if (e & 1) { + if (msg_strs[0] == i && + msg_strs[1] == j && + msg_strs[2]) + printf("%s ", msg_strs+2); + else + printf("%d:%d ", i, j); + } + e >>= 1; + } + } +} + +int validate_cpu(void) +{ + u32 *err_flags; + int cpu_level, req_level; + + check_cpu(&cpu_level, &req_level, &err_flags); + + if (cpu_level < req_level) { + printf("This kernel requires an %s CPU, ", + cpu_name(req_level)); + printf("but only detected an %s CPU.\n", + cpu_name(cpu_level)); + return -1; + } + + if (err_flags) { + puts("This kernel requires the following features " + "not present on the CPU:\n"); + show_cap_strs(err_flags); + putchar('\n'); + return -1; + } else if (check_knl_erratum()) { + return -1; + } else { + return 0; + } +} diff --git a/arch/x86/boot/cpucheck.c b/arch/x86/boot/cpucheck.c new file mode 100644 index 000000000..2e1bb936c --- /dev/null +++ b/arch/x86/boot/cpucheck.c @@ -0,0 +1,228 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Check for obligatory CPU features and abort if the features are not + * present. This code should be compilable as 16-, 32- or 64-bit + * code, so be very careful with types and inline assembly. + * + * This code should not contain any messages; that requires an + * additional wrapper. + * + * As written, this code is not safe for inclusion into the kernel + * proper (after FPU initialization, in particular). + */ + +#ifdef _SETUP +# include "boot.h" +#endif +#include <linux/types.h> +#include <asm/cpufeaturemasks.h> +#include <asm/intel-family.h> +#include <asm/processor-flags.h> +#include <asm/msr-index.h> +#include <asm/shared/msr.h> + +#include "string.h" + +static u32 err_flags[NCAPINTS]; + +static const int req_level = CONFIG_X86_MINIMUM_CPU_FAMILY; + +static const u32 req_flags[NCAPINTS] = +{ + REQUIRED_MASK0, + REQUIRED_MASK1, + 0, /* REQUIRED_MASK2 not implemented in this file */ + 0, /* REQUIRED_MASK3 not implemented in this file */ + REQUIRED_MASK4, + 0, /* REQUIRED_MASK5 not implemented in this file */ + REQUIRED_MASK6, + 0, /* REQUIRED_MASK7 not implemented in this file */ + 0, /* REQUIRED_MASK8 not implemented in this file */ + 0, /* REQUIRED_MASK9 not implemented in this file */ + 0, /* REQUIRED_MASK10 not implemented in this file */ + 0, /* REQUIRED_MASK11 not implemented in this file */ + 0, /* REQUIRED_MASK12 not implemented in this file */ + 0, /* REQUIRED_MASK13 not implemented in this file */ + 0, /* REQUIRED_MASK14 not implemented in this file */ + 0, /* REQUIRED_MASK15 not implemented in this file */ + REQUIRED_MASK16, +}; + +#define A32(a, b, c, d) (((d) << 24)+((c) << 16)+((b) << 8)+(a)) + +static int is_amd(void) +{ + return cpu_vendor[0] == A32('A', 'u', 't', 'h') && + cpu_vendor[1] == A32('e', 'n', 't', 'i') && + cpu_vendor[2] == A32('c', 'A', 'M', 'D'); +} + +static int is_centaur(void) +{ + return cpu_vendor[0] == A32('C', 'e', 'n', 't') && + cpu_vendor[1] == A32('a', 'u', 'r', 'H') && + cpu_vendor[2] == A32('a', 'u', 'l', 's'); +} + +static int is_transmeta(void) +{ + return cpu_vendor[0] == A32('G', 'e', 'n', 'u') && + cpu_vendor[1] == A32('i', 'n', 'e', 'T') && + cpu_vendor[2] == A32('M', 'x', '8', '6'); +} + +static int is_intel(void) +{ + return cpu_vendor[0] == A32('G', 'e', 'n', 'u') && + cpu_vendor[1] == A32('i', 'n', 'e', 'I') && + cpu_vendor[2] == A32('n', 't', 'e', 'l'); +} + +/* Returns a bitmask of which words we have error bits in */ +static int check_cpuflags(void) +{ + u32 err; + int i; + + err = 0; + for (i = 0; i < NCAPINTS; i++) { + err_flags[i] = req_flags[i] & ~cpu.flags[i]; + if (err_flags[i]) + err |= 1 << i; + } + + return err; +} + +/* + * Returns -1 on error. + * + * *cpu_level is set to the current CPU level; *req_level to the required + * level. x86-64 is considered level 64 for this purpose. + * + * *err_flags_ptr is set to the flags error array if there are flags missing. + */ +int check_cpu(int *cpu_level_ptr, int *req_level_ptr, u32 **err_flags_ptr) +{ + int err; + + memset(&cpu.flags, 0, sizeof(cpu.flags)); + cpu.level = 3; + + if (has_eflag(X86_EFLAGS_AC)) + cpu.level = 4; + + get_cpuflags(); + err = check_cpuflags(); + + if (test_bit(X86_FEATURE_LM, cpu.flags)) + cpu.level = 64; + + if (err == 0x01 && + !(err_flags[0] & + ~((1 << X86_FEATURE_XMM)|(1 << X86_FEATURE_XMM2))) && + is_amd()) { + /* If this is an AMD and we're only missing SSE+SSE2, try to + turn them on */ + + struct msr m; + + raw_rdmsr(MSR_K7_HWCR, &m); + m.l &= ~(1 << 15); + raw_wrmsr(MSR_K7_HWCR, &m); + + get_cpuflags(); /* Make sure it really did something */ + err = check_cpuflags(); + } else if (err == 0x01 && + !(err_flags[0] & ~(1 << X86_FEATURE_CX8)) && + is_centaur() && cpu.model >= 6) { + /* If this is a VIA C3, we might have to enable CX8 + explicitly */ + + struct msr m; + + raw_rdmsr(MSR_VIA_FCR, &m); + m.l |= (1 << 1) | (1 << 7); + raw_wrmsr(MSR_VIA_FCR, &m); + + set_bit(X86_FEATURE_CX8, cpu.flags); + err = check_cpuflags(); + } else if (err == 0x01 && is_transmeta()) { + /* Transmeta might have masked feature bits in word 0 */ + + struct msr m, m_tmp; + u32 level = 1; + + raw_rdmsr(0x80860004, &m); + m_tmp = m; + m_tmp.l = ~0; + raw_wrmsr(0x80860004, &m_tmp); + asm("cpuid" + : "+a" (level), "=d" (cpu.flags[0]) + : : "ecx", "ebx"); + raw_wrmsr(0x80860004, &m); + + err = check_cpuflags(); + } else if (err == 0x01 && + !(err_flags[0] & ~(1 << X86_FEATURE_PAE)) && + is_intel() && cpu.level == 6 && + (cpu.model == 9 || cpu.model == 13)) { + /* PAE is disabled on this Pentium M but can be forced */ + if (cmdline_find_option_bool("forcepae")) { + puts("WARNING: Forcing PAE in CPU flags\n"); + set_bit(X86_FEATURE_PAE, cpu.flags); + err = check_cpuflags(); + } + else { + puts("WARNING: PAE disabled. Use parameter 'forcepae' to enable at your own risk!\n"); + } + } + if (!err) + err = check_knl_erratum(); + + if (err_flags_ptr) + *err_flags_ptr = err ? err_flags : NULL; + if (cpu_level_ptr) + *cpu_level_ptr = cpu.level; + if (req_level_ptr) + *req_level_ptr = req_level; + + return (cpu.level < req_level || err) ? -1 : 0; +} + +int check_knl_erratum(void) +{ + /* + * First check for the affected model/family: + */ + if (!is_intel() || + cpu.family != 6 || + cpu.model != 0x57 /*INTEL_XEON_PHI_KNL*/) + return 0; + + /* + * This erratum affects the Accessed/Dirty bits, and can + * cause stray bits to be set in !Present PTEs. We have + * enough bits in our 64-bit PTEs (which we have on real + * 64-bit mode or PAE) to avoid using these troublesome + * bits. But, we do not have enough space in our 32-bit + * PTEs. So, refuse to run on 32-bit non-PAE kernels. + */ + if (IS_ENABLED(CONFIG_X86_64) || IS_ENABLED(CONFIG_X86_PAE)) + return 0; + + puts("This 32-bit kernel can not run on this Xeon Phi x200\n" + "processor due to a processor erratum. Use a 64-bit\n" + "kernel, or enable PAE in this 32-bit kernel.\n\n"); + + return -1; +} + + diff --git a/arch/x86/boot/cpuflags.c b/arch/x86/boot/cpuflags.c new file mode 100644 index 000000000..916bac09b --- /dev/null +++ b/arch/x86/boot/cpuflags.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/types.h> +#include "bitops.h" + +#include <asm/processor-flags.h> +#include <asm/msr-index.h> +#include "cpuflags.h" + +struct cpu_features cpu; +u32 cpu_vendor[3]; + +static bool loaded_flags; + +static int has_fpu(void) +{ + u16 fcw = -1, fsw = -1; + unsigned long cr0; + + asm volatile("mov %%cr0,%0" : "=r" (cr0)); + if (cr0 & (X86_CR0_EM|X86_CR0_TS)) { + cr0 &= ~(X86_CR0_EM|X86_CR0_TS); + asm volatile("mov %0,%%cr0" : : "r" (cr0)); + } + + asm volatile("fninit ; fnstsw %0 ; fnstcw %1" + : "+m" (fsw), "+m" (fcw)); + + return fsw == 0 && (fcw & 0x103f) == 0x003f; +} + +#ifdef CONFIG_X86_32 +/* + * For building the 16-bit code we want to explicitly specify 32-bit + * push/pop operations, rather than just saying 'pushf' or 'popf' and + * letting the compiler choose. + */ +bool has_eflag(unsigned long mask) +{ + unsigned long f0, f1; + + asm volatile("pushfl \n\t" + "pushfl \n\t" + "pop %0 \n\t" + "mov %0,%1 \n\t" + "xor %2,%1 \n\t" + "push %1 \n\t" + "popfl \n\t" + "pushfl \n\t" + "pop %1 \n\t" + "popfl" + : "=&r" (f0), "=&r" (f1) + : "ri" (mask)); + + return !!((f0^f1) & mask); +} +#endif + +void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d) +{ + asm volatile("cpuid" + : "=a" (*a), "=b" (*b), "=c" (*c), "=d" (*d) + : "0" (id), "2" (count) + ); +} + +#define cpuid(id, a, b, c, d) cpuid_count(id, 0, a, b, c, d) + +void get_cpuflags(void) +{ + u32 max_intel_level, max_amd_level; + u32 tfms; + u32 ignored; + + if (loaded_flags) + return; + loaded_flags = true; + + if (has_fpu()) + set_bit(X86_FEATURE_FPU, cpu.flags); + + if (has_eflag(X86_EFLAGS_ID)) { + cpuid(0x0, &max_intel_level, &cpu_vendor[0], &cpu_vendor[2], + &cpu_vendor[1]); + + if (max_intel_level >= 0x00000001 && + max_intel_level <= 0x0000ffff) { + cpuid(0x1, &tfms, &ignored, &cpu.flags[4], + &cpu.flags[0]); + cpu.level = (tfms >> 8) & 15; + cpu.family = cpu.level; + cpu.model = (tfms >> 4) & 15; + if (cpu.level >= 6) + cpu.model += ((tfms >> 16) & 0xf) << 4; + } + + if (max_intel_level >= 0x00000007) { + cpuid_count(0x00000007, 0, &ignored, &ignored, + &cpu.flags[16], &ignored); + } + + cpuid(0x80000000, &max_amd_level, &ignored, &ignored, + &ignored); + + if (max_amd_level >= 0x80000001 && + max_amd_level <= 0x8000ffff) { + cpuid(0x80000001, &ignored, &ignored, &cpu.flags[6], + &cpu.flags[1]); + } + } +} diff --git a/arch/x86/boot/cpuflags.h b/arch/x86/boot/cpuflags.h new file mode 100644 index 000000000..a398d9204 --- /dev/null +++ b/arch/x86/boot/cpuflags.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_CPUFLAGS_H +#define BOOT_CPUFLAGS_H + +#include <asm/cpufeatures.h> +#include <asm/processor-flags.h> + +struct cpu_features { + int level; /* Family, or 64 for x86-64 */ + int family; /* Family, always */ + int model; + u32 flags[NCAPINTS]; +}; + +extern struct cpu_features cpu; +extern u32 cpu_vendor[3]; + +#ifdef CONFIG_X86_32 +bool has_eflag(unsigned long mask); +#else +static inline bool has_eflag(unsigned long mask) { return true; } +#endif +void get_cpuflags(void); +void cpuid_count(u32 id, u32 count, u32 *a, u32 *b, u32 *c, u32 *d); +bool has_cpuflag(int flag); + +#endif diff --git a/arch/x86/boot/ctype.h b/arch/x86/boot/ctype.h new file mode 100644 index 000000000..8f5ef2994 --- /dev/null +++ b/arch/x86/boot/ctype.h @@ -0,0 +1,21 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_CTYPE_H +#define BOOT_CTYPE_H + +static inline int isdigit(int ch) +{ + return (ch >= '0') && (ch <= '9'); +} + +static inline int isxdigit(int ch) +{ + if (isdigit(ch)) + return true; + + if ((ch >= 'a') && (ch <= 'f')) + return true; + + return (ch >= 'A') && (ch <= 'F'); +} + +#endif diff --git a/arch/x86/boot/early_serial_console.c b/arch/x86/boot/early_serial_console.c new file mode 100644 index 000000000..5b83beab8 --- /dev/null +++ b/arch/x86/boot/early_serial_console.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Serial port routines for use during early boot reporting. This code is + * included from both the compressed kernel and the regular kernel. + */ +#include "boot.h" + +#define DEFAULT_SERIAL_PORT 0x3f8 /* ttyS0 */ + +#define DLAB 0x80 + +#define TXR 0 /* Transmit register (WRITE) */ +#define RXR 0 /* Receive register (READ) */ +#define IER 1 /* Interrupt Enable */ +#define IIR 2 /* Interrupt ID */ +#define FCR 2 /* FIFO control */ +#define LCR 3 /* Line control */ +#define MCR 4 /* Modem control */ +#define LSR 5 /* Line Status */ +#define MSR 6 /* Modem Status */ +#define DLL 0 /* Divisor Latch Low */ +#define DLH 1 /* Divisor latch High */ + +#define DEFAULT_BAUD 9600 + +static void early_serial_init(int port, int baud) +{ + unsigned char c; + unsigned divisor; + + outb(0x3, port + LCR); /* 8n1 */ + outb(0, port + IER); /* no interrupt */ + outb(0, port + FCR); /* no fifo */ + outb(0x3, port + MCR); /* DTR + RTS */ + + divisor = 115200 / baud; + c = inb(port + LCR); + outb(c | DLAB, port + LCR); + outb(divisor & 0xff, port + DLL); + outb((divisor >> 8) & 0xff, port + DLH); + outb(c & ~DLAB, port + LCR); + + early_serial_base = port; +} + +static void parse_earlyprintk(void) +{ + int baud = DEFAULT_BAUD; + char arg[32]; + int pos = 0; + int port = 0; + + if (cmdline_find_option("earlyprintk", arg, sizeof(arg)) > 0) { + char *e; + + if (!strncmp(arg, "serial", 6)) { + port = DEFAULT_SERIAL_PORT; + pos += 6; + } + + if (arg[pos] == ',') + pos++; + + /* + * make sure we have + * "serial,0x3f8,115200" + * "serial,ttyS0,115200" + * "ttyS0,115200" + */ + if (pos == 7 && !strncmp(arg + pos, "0x", 2)) { + port = simple_strtoull(arg + pos, &e, 16); + if (port == 0 || arg + pos == e) + port = DEFAULT_SERIAL_PORT; + else + pos = e - arg; + } else if (!strncmp(arg + pos, "ttyS", 4)) { + static const int bases[] = { 0x3f8, 0x2f8 }; + int idx = 0; + + /* += strlen("ttyS"); */ + pos += 4; + + if (arg[pos++] == '1') + idx = 1; + + port = bases[idx]; + } + + if (arg[pos] == ',') + pos++; + + baud = simple_strtoull(arg + pos, &e, 0); + if (baud == 0 || arg + pos == e) + baud = DEFAULT_BAUD; + } + + if (port) + early_serial_init(port, baud); +} + +#define BASE_BAUD (1843200/16) +static unsigned int probe_baud(int port) +{ + unsigned char lcr, dll, dlh; + unsigned int quot; + + lcr = inb(port + LCR); + outb(lcr | DLAB, port + LCR); + dll = inb(port + DLL); + dlh = inb(port + DLH); + outb(lcr, port + LCR); + quot = (dlh << 8) | dll; + + return BASE_BAUD / quot; +} + +static void parse_console_uart8250(void) +{ + char optstr[64], *options; + int baud; + int port = 0; + + /* + * console=uart8250,io,0x3f8,115200n8 + * need to make sure it is last one console ! + */ + if (cmdline_find_option("console", optstr, sizeof(optstr)) <= 0) + return; + + options = optstr; + + if (!strncmp(options, "uart8250,io,", 12)) + port = simple_strtoull(options + 12, &options, 0); + else if (!strncmp(options, "uart,io,", 8)) + port = simple_strtoull(options + 8, &options, 0); + else + return; + + if (options && (options[0] == ',')) { + baud = simple_strtoull(options + 1, NULL, 0); + if (!baud) + baud = DEFAULT_BAUD; + } else { + baud = probe_baud(port); + } + + if (port) + early_serial_init(port, baud); +} + +void console_init(void) +{ + parse_earlyprintk(); + + if (!early_serial_base) + parse_console_uart8250(); +} diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c new file mode 100644 index 000000000..9956c6115 --- /dev/null +++ b/arch/x86/boot/edd.c @@ -0,0 +1,176 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Get EDD BIOS disk information + */ + +#include "boot.h" +#include <linux/edd.h> +#include "string.h" + +#if IS_ENABLED(CONFIG_EDD) + +/* + * Read the MBR (first sector) from a specific device. + */ +static int read_mbr(u8 devno, void *buf) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ax = 0x0201; /* Legacy Read, one sector */ + ireg.cx = 0x0001; /* Sector 0-0-1 */ + ireg.dl = devno; + ireg.bx = (size_t)buf; + + intcall(0x13, &ireg, &oreg); + + return -(oreg.eflags & X86_EFLAGS_CF); /* 0 or -1 */ +} + +static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig) +{ + int sector_size; + char *mbrbuf_ptr, *mbrbuf_end; + u32 buf_base, mbr_base; + extern char _end[]; + u16 mbr_magic; + + sector_size = ei->params.bytes_per_sector; + if (!sector_size) + sector_size = 512; /* Best available guess */ + + /* Produce a naturally aligned buffer on the heap */ + buf_base = (ds() << 4) + (u32)&_end; + mbr_base = (buf_base+sector_size-1) & ~(sector_size-1); + mbrbuf_ptr = _end + (mbr_base-buf_base); + mbrbuf_end = mbrbuf_ptr + sector_size; + + /* Make sure we actually have space on the heap... */ + if (!(boot_params.hdr.loadflags & CAN_USE_HEAP)) + return -1; + if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr) + return -1; + + memset(mbrbuf_ptr, 0, sector_size); + if (read_mbr(devno, mbrbuf_ptr)) + return -1; + + *mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET]; + mbr_magic = *(u16 *)&mbrbuf_ptr[510]; + + /* check for valid MBR magic */ + return mbr_magic == 0xAA55 ? 0 : -1; +} + +static int get_edd_info(u8 devno, struct edd_info *ei) +{ + struct biosregs ireg, oreg; + + memset(ei, 0, sizeof(*ei)); + + /* Check Extensions Present */ + + initregs(&ireg); + ireg.ah = 0x41; + ireg.bx = EDDMAGIC1; + ireg.dl = devno; + intcall(0x13, &ireg, &oreg); + + if (oreg.eflags & X86_EFLAGS_CF) + return -1; /* No extended information */ + + if (oreg.bx != EDDMAGIC2) + return -1; + + ei->device = devno; + ei->version = oreg.ah; /* EDD version number */ + ei->interface_support = oreg.cx; /* EDD functionality subsets */ + + /* Extended Get Device Parameters */ + + ei->params.length = sizeof(ei->params); + ireg.ah = 0x48; + ireg.si = (size_t)&ei->params; + intcall(0x13, &ireg, &oreg); + + /* Get legacy CHS parameters */ + + /* Ralf Brown recommends setting ES:DI to 0:0 */ + ireg.ah = 0x08; + ireg.es = 0; + intcall(0x13, &ireg, &oreg); + + if (!(oreg.eflags & X86_EFLAGS_CF)) { + ei->legacy_max_cylinder = oreg.ch + ((oreg.cl & 0xc0) << 2); + ei->legacy_max_head = oreg.dh; + ei->legacy_sectors_per_track = oreg.cl & 0x3f; + } + + return 0; +} + +void query_edd(void) +{ + char eddarg[8]; + bool do_mbr = true; + bool do_edd = !IS_ENABLED(CONFIG_EDD_OFF); + bool be_quiet; + int devno; + struct edd_info ei, *edp; + u32 *mbrptr; + + if (cmdline_find_option("edd", eddarg, sizeof(eddarg)) > 0) { + if (!strcmp(eddarg, "skipmbr") || !strcmp(eddarg, "skip")) { + do_edd = true; + do_mbr = false; + } + else if (!strcmp(eddarg, "off")) + do_edd = false; + else if (!strcmp(eddarg, "on")) + do_edd = true; + } + + be_quiet = cmdline_find_option_bool("quiet"); + + edp = boot_params.eddbuf; + mbrptr = boot_params.edd_mbr_sig_buffer; + + if (!do_edd) + return; + + /* Bugs in OnBoard or AddOnCards Bios may hang the EDD probe, + * so give a hint if this happens. + */ + + if (!be_quiet) + printf("Probing EDD (edd=off to disable)... "); + + for (devno = 0x80; devno < 0x80+EDD_MBR_SIG_MAX; devno++) { + /* + * Scan the BIOS-supported hard disks and query EDD + * information... + */ + if (!get_edd_info(devno, &ei) + && boot_params.eddbuf_entries < EDDMAXNR) { + memcpy(edp, &ei, sizeof(ei)); + edp++; + boot_params.eddbuf_entries++; + } + + if (do_mbr && !read_mbr_sig(devno, &ei, mbrptr++)) + boot_params.edd_mbr_sig_buf_entries = devno-0x80+1; + } + + if (!be_quiet) + printf("ok\n"); +} + +#endif diff --git a/arch/x86/boot/genimage.sh b/arch/x86/boot/genimage.sh new file mode 100644 index 000000000..3882ead51 --- /dev/null +++ b/arch/x86/boot/genimage.sh @@ -0,0 +1,275 @@ +#!/bin/bash +# +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (C) 2017 by Changbin Du <changbin.du@intel.com> +# +# Adapted from code in arch/x86/boot/Makefile by H. Peter Anvin and others +# +# "make fdimage/fdimage144/fdimage288/hdimage/isoimage" +# script for x86 architecture +# +# Arguments: +# $1 - fdimage format +# $2 - target image file +# $3 - kernel bzImage file +# $4 - mtools configuration file +# $5 - kernel cmdline +# $6+ - initrd image file(s) +# +# This script requires: +# bash +# syslinux +# genisoimage +# mtools (for fdimage* and hdimage) +# edk2/OVMF (for hdimage) +# +# Otherwise try to stick to POSIX shell commands... +# + +# Use "make V=1" to debug this script +case "${KBUILD_VERBOSE}" in +*1*) + set -x + ;; +esac + +# Exit the top-level shell with an error +topshell=$$ +trap 'exit 1' USR1 +die() { + echo "" 1>&2 + echo " *** $*" 1>&2 + echo "" 1>&2 + kill -USR1 $topshell +} + +# Verify the existence and readability of a file +verify() { + if [ ! -f "$1" -o ! -r "$1" ]; then + die "Missing file: $1" + fi +} + +diskfmt="$1" +FIMAGE="$2" +FBZIMAGE="$3" +MTOOLSRC="$4" +KCMDLINE="$5" +shift 5 # Remaining arguments = initrd files + +export MTOOLSRC + +# common options for dd +dd='dd iflag=fullblock' + +# Make sure the files actually exist +verify "$FBZIMAGE" + +declare -a FDINITRDS +irdpfx=' initrd=' +initrdopts_syslinux='' +initrdopts_efi='' +for f in "$@"; do + if [ -f "$f" -a -r "$f" ]; then + FDINITRDS=("${FDINITRDS[@]}" "$f") + fname="$(basename "$f")" + initrdopts_syslinux="${initrdopts_syslinux}${irdpfx}${fname}" + irdpfx=, + initrdopts_efi="${initrdopts_efi} initrd=${fname}" + fi +done + +# Read a $3-byte littleendian unsigned value at offset $2 from file $1 +le() { + local n=0 + local m=1 + for b in $(od -A n -v -j $2 -N $3 -t u1 "$1"); do + n=$((n + b*m)) + m=$((m * 256)) + done + echo $n +} + +# Get the EFI architecture name such that boot{name}.efi is the default +# boot file name. Returns false with no output if the file is not an +# EFI image or otherwise unknown. +efiarch() { + [ -f "$1" ] || return + [ $(le "$1" 0 2) -eq 23117 ] || return # MZ magic + peoffs=$(le "$1" 60 4) # PE header offset + [ $peoffs -ge 64 ] || return + [ $(le "$1" $peoffs 4) -eq 17744 ] || return # PE magic + case $(le "$1" $((peoffs+4+20)) 2) in # PE type + 267) ;; # PE32 + 523) ;; # PE32+ + *) return 1 ;; # Invalid + esac + [ $(le "$1" $((peoffs+4+20+68)) 2) -eq 10 ] || return # EFI app + case $(le "$1" $((peoffs+4)) 2) in # Machine type + 332) echo i386 ;; + 450) echo arm ;; + 512) echo ia64 ;; + 20530) echo riscv32 ;; + 20580) echo riscv64 ;; + 20776) echo riscv128 ;; + 34404) echo x64 ;; + 43620) echo aa64 ;; + esac +} + +# Get the combined sizes in bytes of the files given, counting sparse +# files as full length, and padding each file to cluster size +cluster=16384 +filesizes() { + local t=0 + local s + for s in $(ls -lnL "$@" 2>/dev/null | awk '/^-/{ print $5; }'); do + t=$((t + ((s+cluster-1)/cluster)*cluster)) + done + echo $t +} + +# Expand directory names which should be in /usr/share into a list +# of possible alternatives +sharedirs() { + local dir file + for dir in /usr/share /usr/lib64 /usr/lib; do + for file; do + echo "$dir/$file" + echo "$dir/${file^^}" + done + done +} +efidirs() { + local dir file + for dir in /usr/share /boot /usr/lib64 /usr/lib; do + for file; do + echo "$dir/$file" + echo "$dir/${file^^}" + done + done +} + +findsyslinux() { + local f="$(find -L $(sharedirs syslinux isolinux) \ + -name "$1" -readable -type f -print -quit 2>/dev/null)" + if [ ! -f "$f" ]; then + die "Need a $1 file, please install syslinux/isolinux." + fi + echo "$f" + return 0 +} + +findovmf() { + local arch="$1" + shift + local -a names=(-false) + local name f + for name; do + names=("${names[@]}" -or -iname "$name") + done + for f in $(find -L $(efidirs edk2 ovmf) \ + \( "${names[@]}" \) -readable -type f \ + -print 2>/dev/null); do + if [ "$(efiarch "$f")" = "$arch" ]; then + echo "$f" + return 0 + fi + done + die "Need a $1 file for $arch, please install EDK2/OVMF." +} + +do_mcopy() { + if [ ${#FDINITRDS[@]} -gt 0 ]; then + mcopy "${FDINITRDS[@]}" "$1" + fi + if [ -n "$efishell" ]; then + mmd "$1"EFI "$1"EFI/Boot + mcopy "$efishell" "$1"EFI/Boot/boot${kefiarch}.efi + fi + if [ -n "$kefiarch" ]; then + echo linux "$KCMDLINE$initrdopts_efi" | \ + mcopy - "$1"startup.nsh + fi + echo default linux "$KCMDLINE$initrdopts_syslinux" | \ + mcopy - "$1"syslinux.cfg + mcopy "$FBZIMAGE" "$1"linux +} + +genbzdisk() { + verify "$MTOOLSRC" + mformat -v 'LINUX_BOOT' a: + syslinux "$FIMAGE" + do_mcopy a: +} + +genfdimage144() { + verify "$MTOOLSRC" + $dd if=/dev/zero of="$FIMAGE" bs=1024 count=1440 2>/dev/null + mformat -v 'LINUX_BOOT' v: + syslinux "$FIMAGE" + do_mcopy v: +} + +genfdimage288() { + verify "$MTOOLSRC" + $dd if=/dev/zero of="$FIMAGE" bs=1024 count=2880 2>/dev/null + mformat -v 'LINUX_BOOT' w: + syslinux "$FIMAGE" + do_mcopy w: +} + +genhdimage() { + verify "$MTOOLSRC" + mbr="$(findsyslinux mbr.bin)" + kefiarch="$(efiarch "$FBZIMAGE")" + if [ -n "$kefiarch" ]; then + # The efishell provides command line handling + efishell="$(findovmf $kefiarch shell.efi shell${kefiarch}.efi)" + ptype='-T 0xef' # EFI system partition, no GPT + fi + sizes=$(filesizes "$FBZIMAGE" "${FDINITRDS[@]}" "$efishell") + # Allow 1% + 2 MiB for filesystem and partition table overhead, + # syslinux, and config files; this is probably excessive... + megs=$(((sizes + sizes/100 + 2*1024*1024 - 1)/(1024*1024))) + $dd if=/dev/zero of="$FIMAGE" bs=$((1024*1024)) count=$megs 2>/dev/null + mpartition -I -c -s 32 -h 64 $ptype -b 64 -a p: + $dd if="$mbr" of="$FIMAGE" bs=440 count=1 conv=notrunc 2>/dev/null + mformat -v 'LINUX_BOOT' -s 32 -h 64 -c $((cluster/512)) -t $megs h: + syslinux --offset $((64*512)) "$FIMAGE" + do_mcopy h: +} + +geniso() { + tmp_dir="$(dirname "$FIMAGE")/isoimage" + rm -rf "$tmp_dir" + mkdir "$tmp_dir" + isolinux=$(findsyslinux isolinux.bin) + ldlinux=$(findsyslinux ldlinux.c32) + cp "$isolinux" "$ldlinux" "$tmp_dir" + cp "$FBZIMAGE" "$tmp_dir"/linux + echo default linux "$KCMDLINE" > "$tmp_dir"/isolinux.cfg + if [ ${#FDINITRDS[@]} -gt 0 ]; then + cp "${FDINITRDS[@]}" "$tmp_dir"/ + fi + genisoimage -J -r -appid 'LINUX_BOOT' -input-charset=utf-8 \ + -quiet -o "$FIMAGE" -b isolinux.bin \ + -c boot.cat -no-emul-boot -boot-load-size 4 \ + -boot-info-table "$tmp_dir" + isohybrid "$FIMAGE" 2>/dev/null || true + rm -rf "$tmp_dir" +} + +rm -f "$FIMAGE" + +case "$diskfmt" in + bzdisk) genbzdisk;; + fdimage144) genfdimage144;; + fdimage288) genfdimage288;; + hdimage) genhdimage;; + isoimage) geniso;; + *) die "Unknown image format: $diskfmt";; +esac diff --git a/arch/x86/boot/header.S b/arch/x86/boot/header.S new file mode 100644 index 000000000..9bea5a1e2 --- /dev/null +++ b/arch/x86/boot/header.S @@ -0,0 +1,619 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * header.S + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * Based on bootsect.S and setup.S + * modified by more people than can be counted + * + * Rewritten as a common file by H. Peter Anvin (Apr 2007) + * + * BIG FAT NOTE: We're in real mode using 64k segments. Therefore segment + * addresses must be multiplied by 16 to obtain their respective linear + * addresses. To avoid confusion, linear addresses are written using leading + * hex while segment addresses are written as segment:offset. + * + */ +#include <linux/pe.h> +#include <asm/segment.h> +#include <asm/boot.h> +#include <asm/page_types.h> +#include <asm/setup.h> +#include <asm/bootparam.h> +#include "boot.h" +#include "voffset.h" +#include "zoffset.h" + +BOOTSEG = 0x07C0 /* original address of boot-sector */ +SYSSEG = 0x1000 /* historical load address >> 4 */ + +#ifndef SVGA_MODE +#define SVGA_MODE ASK_VGA +#endif + +#ifndef ROOT_RDONLY +#define ROOT_RDONLY 1 +#endif + + .set salign, 0x1000 + .set falign, 0x200 + + .code16 + .section ".bstext", "ax" +#ifdef CONFIG_EFI_STUB + # "MZ", MS-DOS header + .word IMAGE_DOS_SIGNATURE + .org 0x38 + # + # Offset to the PE header. + # + .long LINUX_PE_MAGIC + .long pe_header +pe_header: + .long IMAGE_NT_SIGNATURE + +coff_header: +#ifdef CONFIG_X86_32 + .set image_file_add_flags, IMAGE_FILE_32BIT_MACHINE + .set pe_opt_magic, IMAGE_NT_OPTIONAL_HDR32_MAGIC + .word IMAGE_FILE_MACHINE_I386 +#else + .set image_file_add_flags, 0 + .set pe_opt_magic, IMAGE_NT_OPTIONAL_HDR64_MAGIC + .word IMAGE_FILE_MACHINE_AMD64 +#endif + .word section_count # nr_sections + .long 0 # TimeDateStamp + .long 0 # PointerToSymbolTable + .long 1 # NumberOfSymbols + .word section_table - optional_header # SizeOfOptionalHeader + .word IMAGE_FILE_EXECUTABLE_IMAGE | \ + image_file_add_flags | \ + IMAGE_FILE_DEBUG_STRIPPED | \ + IMAGE_FILE_LINE_NUMS_STRIPPED # Characteristics + +optional_header: + .word pe_opt_magic + .byte 0x02 # MajorLinkerVersion + .byte 0x14 # MinorLinkerVersion + + .long ZO__data # SizeOfCode + + .long ZO__end - ZO__data # SizeOfInitializedData + .long 0 # SizeOfUninitializedData + + .long setup_size + ZO_efi_pe_entry # AddressOfEntryPoint + + .long setup_size # BaseOfCode +#ifdef CONFIG_X86_32 + .long 0 # data +#endif + +extra_header_fields: +#ifdef CONFIG_X86_32 + .long 0 # ImageBase +#else + .quad 0 # ImageBase +#endif + .long salign # SectionAlignment + .long falign # FileAlignment + .word 0 # MajorOperatingSystemVersion + .word 0 # MinorOperatingSystemVersion + .word LINUX_EFISTUB_MAJOR_VERSION # MajorImageVersion + .word LINUX_EFISTUB_MINOR_VERSION # MinorImageVersion + .word 0 # MajorSubsystemVersion + .word 0 # MinorSubsystemVersion + .long 0 # Win32VersionValue + + .long setup_size + ZO__end # SizeOfImage + + .long salign # SizeOfHeaders + .long 0 # CheckSum + .word IMAGE_SUBSYSTEM_EFI_APPLICATION # Subsystem (EFI application) + .word IMAGE_DLLCHARACTERISTICS_NX_COMPAT # DllCharacteristics +#ifdef CONFIG_X86_32 + .long 0 # SizeOfStackReserve + .long 0 # SizeOfStackCommit + .long 0 # SizeOfHeapReserve + .long 0 # SizeOfHeapCommit +#else + .quad 0 # SizeOfStackReserve + .quad 0 # SizeOfStackCommit + .quad 0 # SizeOfHeapReserve + .quad 0 # SizeOfHeapCommit +#endif + .long 0 # LoaderFlags + .long (section_table - .) / 8 # NumberOfRvaAndSizes + + .quad 0 # ExportTable + .quad 0 # ImportTable + .quad 0 # ResourceTable + .quad 0 # ExceptionTable + .quad 0 # CertificationTable + .quad 0 # BaseRelocationTable + + # Section table +section_table: + .ascii ".setup" + .byte 0 + .byte 0 + .long pecompat_fstart - salign # VirtualSize + .long salign # VirtualAddress + .long pecompat_fstart - salign # SizeOfRawData + .long salign # PointerToRawData + + .long 0, 0, 0 + .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_DISCARDABLE # Characteristics + +#ifdef CONFIG_EFI_MIXED + .asciz ".compat" + + .long pecompat_fsize # VirtualSize + .long pecompat_fstart # VirtualAddress + .long pecompat_fsize # SizeOfRawData + .long pecompat_fstart # PointerToRawData + + .long 0, 0, 0 + .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_DISCARDABLE # Characteristics + + /* + * Put the IA-32 machine type and the associated entry point address in + * the .compat section, so loaders can figure out which other execution + * modes this image supports. + */ + .pushsection ".pecompat", "a", @progbits + .balign salign + .globl pecompat_fstart +pecompat_fstart: + .byte 0x1 # Version + .byte 8 # Size + .word IMAGE_FILE_MACHINE_I386 # PE machine type + .long setup_size + ZO_efi32_pe_entry # Entrypoint + .byte 0x0 # Sentinel + .popsection +#else + .set pecompat_fstart, setup_size +#endif + .ascii ".text\0\0\0" + .long textsize # VirtualSize + .long setup_size # VirtualAddress + .long textsize # SizeOfRawData + .long setup_size # PointerToRawData + .long 0 # PointerToRelocations + .long 0 # PointerToLineNumbers + .word 0 # NumberOfRelocations + .word 0 # NumberOfLineNumbers + .long IMAGE_SCN_CNT_CODE | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_EXECUTE # Characteristics + +#ifdef CONFIG_EFI_SBAT + .ascii ".sbat\0\0\0" + .long ZO__esbat - ZO__sbat # VirtualSize + .long setup_size + ZO__sbat # VirtualAddress + .long ZO__esbat - ZO__sbat # SizeOfRawData + .long setup_size + ZO__sbat # PointerToRawData + + .long 0, 0, 0 + .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_DISCARDABLE # Characteristics + + .set textsize, ZO__sbat +#else + .set textsize, ZO__data +#endif + + .ascii ".data\0\0\0" + .long ZO__end - ZO__data # VirtualSize + .long setup_size + ZO__data # VirtualAddress + .long ZO__edata - ZO__data # SizeOfRawData + .long setup_size + ZO__data # PointerToRawData + + .long 0, 0, 0 + .long IMAGE_SCN_CNT_INITIALIZED_DATA | \ + IMAGE_SCN_MEM_READ | \ + IMAGE_SCN_MEM_WRITE # Characteristics + + .set section_count, (. - section_table) / 40 +#endif /* CONFIG_EFI_STUB */ + + # Kernel attributes; used by setup. This is part 1 of the + # header, from the old boot sector. + + .section ".header", "a" + .globl sentinel +sentinel: .byte 0xff, 0xff /* Used to detect broken loaders */ + + .globl hdr +hdr: + .byte setup_sects - 1 +root_flags: .word ROOT_RDONLY +syssize: .long ZO__edata / 16 +ram_size: .word 0 /* Obsolete */ +vid_mode: .word SVGA_MODE +root_dev: .word 0 /* Default to major/minor 0/0 */ +boot_flag: .word 0xAA55 + + # offset 512, entry point + + .globl _start +_start: + # Explicitly enter this as bytes, or the assembler + # tries to generate a 3-byte jump here, which causes + # everything else to push off to the wrong offset. + .byte 0xeb # short (2-byte) jump + .byte start_of_setup-1f +1: + + # Part 2 of the header, from the old setup.S + + .ascii "HdrS" # header signature + .word 0x020f # header version number (>= 0x0105) + # or else old loadlin-1.5 will fail) + .globl realmode_swtch +realmode_swtch: .word 0, 0 # default_switch, SETUPSEG +start_sys_seg: .word SYSSEG # obsolete and meaningless, but just + # in case something decided to "use" it + .word kernel_version-512 # pointing to kernel version string + # above section of header is compatible + # with loadlin-1.5 (header v1.5). Don't + # change it. + +type_of_loader: .byte 0 # 0 means ancient bootloader, newer + # bootloaders know to change this. + # See Documentation/arch/x86/boot.rst for + # assigned ids + +# flags, unused bits must be zero (RFU) bit within loadflags +loadflags: + .byte LOADED_HIGH # The kernel is to be loaded high + +setup_move_size: .word 0x8000 # size to move, when setup is not + # loaded at 0x90000. We will move setup + # to 0x90000 then just before jumping + # into the kernel. However, only the + # loader knows how much data behind + # us also needs to be loaded. + +code32_start: # here loaders can put a different + # start address for 32-bit code. + .long 0x100000 # 0x100000 = default for big kernel + +ramdisk_image: .long 0 # address of loaded ramdisk image + # Here the loader puts the 32-bit + # address where it loaded the image. + # This only will be read by the kernel. + +ramdisk_size: .long 0 # its size in bytes + +bootsect_kludge: + .long 0 # obsolete + +heap_end_ptr: .word _end+STACK_SIZE-512 + # (Header version 0x0201 or later) + # space from here (exclusive) down to + # end of setup code can be used by setup + # for local heap purposes. + +ext_loader_ver: + .byte 0 # Extended boot loader version +ext_loader_type: + .byte 0 # Extended boot loader type + +cmd_line_ptr: .long 0 # (Header version 0x0202 or later) + # If nonzero, a 32-bit pointer + # to the kernel command line. + # The command line should be + # located between the start of + # setup and the end of low + # memory (0xa0000), or it may + # get overwritten before it + # gets read. If this field is + # used, there is no longer + # anything magical about the + # 0x90000 segment; the setup + # can be located anywhere in + # low memory 0x10000 or higher. + +initrd_addr_max: .long 0x7fffffff + # (Header version 0x0203 or later) + # The highest safe address for + # the contents of an initrd + # The current kernel allows up to 4 GB, + # but leave it at 2 GB to avoid + # possible bootloader bugs. + +kernel_alignment: .long CONFIG_PHYSICAL_ALIGN #physical addr alignment + #required for protected mode + #kernel +#ifdef CONFIG_RELOCATABLE +relocatable_kernel: .byte 1 +#else +relocatable_kernel: .byte 0 +#endif +min_alignment: .byte MIN_KERNEL_ALIGN_LG2 # minimum alignment + +xloadflags: +#ifdef CONFIG_X86_64 +# define XLF0 XLF_KERNEL_64 /* 64-bit kernel */ +#else +# define XLF0 0 +#endif + +#if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64) + /* kernel/boot_param/ramdisk could be loaded above 4g */ +# define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G +#else +# define XLF1 0 +#endif + +#ifdef CONFIG_EFI_HANDOVER_PROTOCOL +# ifdef CONFIG_EFI_MIXED +# define XLF23 (XLF_EFI_HANDOVER_32|XLF_EFI_HANDOVER_64) +# else +# ifdef CONFIG_X86_64 +# define XLF23 XLF_EFI_HANDOVER_64 /* 64-bit EFI handover ok */ +# else +# define XLF23 XLF_EFI_HANDOVER_32 /* 32-bit EFI handover ok */ +# endif +# endif +#else +# define XLF23 0 +#endif + +#if defined(CONFIG_X86_64) && defined(CONFIG_EFI) && defined(CONFIG_KEXEC_CORE) +# define XLF4 XLF_EFI_KEXEC +#else +# define XLF4 0 +#endif + +#ifdef CONFIG_X86_64 +#define XLF56 (XLF_5LEVEL|XLF_5LEVEL_ENABLED) +#else +#define XLF56 0 +#endif + + .word XLF0 | XLF1 | XLF23 | XLF4 | XLF56 + +cmdline_size: .long COMMAND_LINE_SIZE-1 #length of the command line, + #added with boot protocol + #version 2.06 + +hardware_subarch: .long 0 # subarchitecture, added with 2.07 + # default to 0 for normal x86 PC + +hardware_subarch_data: .quad 0 + +payload_offset: .long ZO_input_data +payload_length: .long ZO_z_input_len + +setup_data: .quad 0 # 64-bit physical pointer to + # single linked list of + # struct setup_data + +pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr + +# +# Getting to provably safe in-place decompression is hard. Worst case +# behaviours need to be analyzed. Here let's take the decompression of +# a gzip-compressed kernel as example, to illustrate it: +# +# The file layout of gzip compressed kernel is: +# +# magic[2] +# method[1] +# flags[1] +# timestamp[4] +# extraflags[1] +# os[1] +# compressed data blocks[N] +# crc[4] orig_len[4] +# +# ... resulting in +18 bytes overhead of uncompressed data. +# +# (For more information, please refer to RFC 1951 and RFC 1952.) +# +# Files divided into blocks +# 1 bit (last block flag) +# 2 bits (block type) +# +# 1 block occurs every 32K -1 bytes or when there 50% compression +# has been achieved. The smallest block type encoding is always used. +# +# stored: +# 32 bits length in bytes. +# +# fixed: +# magic fixed tree. +# symbols. +# +# dynamic: +# dynamic tree encoding. +# symbols. +# +# +# The buffer for decompression in place is the length of the uncompressed +# data, plus a small amount extra to keep the algorithm safe. The +# compressed data is placed at the end of the buffer. The output pointer +# is placed at the start of the buffer and the input pointer is placed +# where the compressed data starts. Problems will occur when the output +# pointer overruns the input pointer. +# +# The output pointer can only overrun the input pointer if the input +# pointer is moving faster than the output pointer. A condition only +# triggered by data whose compressed form is larger than the uncompressed +# form. +# +# The worst case at the block level is a growth of the compressed data +# of 5 bytes per 32767 bytes. +# +# The worst case internal to a compressed block is very hard to figure. +# The worst case can at least be bounded by having one bit that represents +# 32764 bytes and then all of the rest of the bytes representing the very +# very last byte. +# +# All of which is enough to compute an amount of extra data that is required +# to be safe. To avoid problems at the block level allocating 5 extra bytes +# per 32767 bytes of data is sufficient. To avoid problems internal to a +# block adding an extra 32767 bytes (the worst case uncompressed block size) +# is sufficient, to ensure that in the worst case the decompressed data for +# block will stop the byte before the compressed data for a block begins. +# To avoid problems with the compressed data's meta information an extra 18 +# bytes are needed. Leading to the formula: +# +# extra_bytes = (uncompressed_size >> 12) + 32768 + 18 +# +# Adding 8 bytes per 32K is a bit excessive but much easier to calculate. +# Adding 32768 instead of 32767 just makes for round numbers. +# +# Above analysis is for decompressing gzip compressed kernel only. Up to +# now 6 different decompressor are supported all together. And among them +# xz stores data in chunks and has maximum chunk of 64K. Hence safety +# margin should be updated to cover all decompressors so that we don't +# need to deal with each of them separately. Please check +# the description in lib/decompressor_xxx.c for specific information. +# +# extra_bytes = (uncompressed_size >> 12) + 65536 + 128 +# +# LZ4 is even worse: data that cannot be further compressed grows by 0.4%, +# or one byte per 256 bytes. OTOH, we can safely get rid of the +128 as +# the size-dependent part now grows so fast. +# +# extra_bytes = (uncompressed_size >> 8) + 65536 +# +# ZSTD compressed data grows by at most 3 bytes per 128K, and only has a 22 +# byte fixed overhead but has a maximum block size of 128K, so it needs a +# larger margin. +# +# extra_bytes = (uncompressed_size >> 8) + 131072 + +#define ZO_z_extra_bytes ((ZO_z_output_len >> 8) + 131072) +#if ZO_z_output_len > ZO_z_input_len +# define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - \ + ZO_z_input_len) +#else +# define ZO_z_extract_offset ZO_z_extra_bytes +#endif + +/* + * The extract_offset has to be bigger than ZO head section. Otherwise when + * the head code is running to move ZO to the end of the buffer, it will + * overwrite the head code itself. + */ +#if (ZO__ehead - ZO_startup_32) > ZO_z_extract_offset +# define ZO_z_min_extract_offset ((ZO__ehead - ZO_startup_32 + 4095) & ~4095) +#else +# define ZO_z_min_extract_offset ((ZO_z_extract_offset + 4095) & ~4095) +#endif + +#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_min_extract_offset) + +#define VO_INIT_SIZE (VO__end - VO__text) +#if ZO_INIT_SIZE > VO_INIT_SIZE +# define INIT_SIZE ZO_INIT_SIZE +#else +# define INIT_SIZE VO_INIT_SIZE +#endif + + .macro __handover_offset +#ifndef CONFIG_EFI_HANDOVER_PROTOCOL + .long 0 +#elif !defined(CONFIG_X86_64) + .long ZO_efi32_stub_entry +#else + /* Yes, this is really how we defined it :( */ + .long ZO_efi64_stub_entry - 0x200 +#ifdef CONFIG_EFI_MIXED + .if ZO_efi32_stub_entry != ZO_efi64_stub_entry - 0x200 + .error "32-bit and 64-bit EFI entry points do not match" + .endif +#endif +#endif + .endm + +init_size: .long INIT_SIZE # kernel initialization size +handover_offset: __handover_offset +kernel_info_offset: .long ZO_kernel_info + +# End of setup header ##################################################### + + .section ".entrytext", "ax" +start_of_setup: +# Force %es = %ds + movw %ds, %ax + movw %ax, %es + cld + +# Apparently some ancient versions of LILO invoked the kernel with %ss != %ds, +# which happened to work by accident for the old code. Recalculate the stack +# pointer if %ss is invalid. Otherwise leave it alone, LOADLIN sets up the +# stack behind its own code, so we can't blindly put it directly past the heap. + + movw %ss, %dx + cmpw %ax, %dx # %ds == %ss? + movw %sp, %dx + je 2f # -> assume %sp is reasonably set + + # Invalid %ss, make up a new stack + movw $_end, %dx + testb $CAN_USE_HEAP, loadflags + jz 1f + movw heap_end_ptr, %dx +1: addw $STACK_SIZE, %dx + jnc 2f + xorw %dx, %dx # Prevent wraparound + +2: # Now %dx should point to the end of our stack space + andw $~3, %dx # dword align (might as well...) + jnz 3f + movw $0xfffc, %dx # Make sure we're not zero +3: movw %ax, %ss + movzwl %dx, %esp # Clear upper half of %esp + sti # Now we should have a working stack + +# We will have entered with %cs = %ds+0x20, normalize %cs so +# it is on par with the other segments. + pushw %ds + pushw $6f + lretw +6: + +# Check signature at end of setup + cmpl $0x5a5aaa55, setup_sig + jne setup_bad + +# Zero the bss + movw $__bss_start, %di + movw $_end+3, %cx + xorl %eax, %eax + subw %di, %cx + shrw $2, %cx + rep stosl + +# Jump to C code (should not return) + calll main + +# Setup corrupt somehow... +setup_bad: + movl $setup_corrupt, %eax + calll puts + # Fall through... + + .globl die + .type die, @function +die: + hlt + jmp die + + .size die, .-die + + .section ".initdata", "a" +setup_corrupt: + .byte 7 + .string "No setup signature found...\n" diff --git a/arch/x86/boot/install.sh b/arch/x86/boot/install.sh new file mode 100755 index 000000000..93784abcd --- /dev/null +++ b/arch/x86/boot/install.sh @@ -0,0 +1,39 @@ +#!/bin/sh +# +# This file is subject to the terms and conditions of the GNU General Public +# License. See the file "COPYING" in the main directory of this archive +# for more details. +# +# Copyright (C) 1995 by Linus Torvalds +# +# Adapted from code in arch/i386/boot/Makefile by H. Peter Anvin +# +# "make install" script for i386 architecture +# +# Arguments: +# $1 - kernel version +# $2 - kernel image file +# $3 - kernel map file +# $4 - default install path (blank if root directory) + +set -e + +if [ -f $4/vmlinuz ]; then + mv $4/vmlinuz $4/vmlinuz.old +fi + +if [ -f $4/System.map ]; then + mv $4/System.map $4/System.old +fi + +cat $2 > $4/vmlinuz +cp $3 $4/System.map + +if [ -x /sbin/lilo ]; then + /sbin/lilo +elif [ -x /etc/lilo/install ]; then + /etc/lilo/install +else + sync + echo "Cannot find LILO." +fi diff --git a/arch/x86/boot/io.h b/arch/x86/boot/io.h new file mode 100644 index 000000000..110880907 --- /dev/null +++ b/arch/x86/boot/io.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_IO_H +#define BOOT_IO_H + +#include <asm/shared/io.h> + +#undef inb +#undef inw +#undef inl +#undef outb +#undef outw +#undef outl + +struct port_io_ops { + u8 (*f_inb)(u16 port); + void (*f_outb)(u8 v, u16 port); + void (*f_outw)(u16 v, u16 port); +}; + +extern struct port_io_ops pio_ops; + +/* + * Use the normal I/O instructions by default. + * TDX guests override these to use hypercalls. + */ +static inline void init_default_io_ops(void) +{ + pio_ops.f_inb = __inb; + pio_ops.f_outb = __outb; + pio_ops.f_outw = __outw; +} + +/* + * Redirect port I/O operations via pio_ops callbacks. + * TDX guests override these callbacks with TDX-specific helpers. + */ +#define inb pio_ops.f_inb +#define outb pio_ops.f_outb +#define outw pio_ops.f_outw + +#endif diff --git a/arch/x86/boot/main.c b/arch/x86/boot/main.c new file mode 100644 index 000000000..4e382d95e --- /dev/null +++ b/arch/x86/boot/main.c @@ -0,0 +1,179 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Main module for the real-mode kernel code + */ +#include <linux/build_bug.h> + +#include "boot.h" +#include "string.h" + +struct boot_params boot_params __attribute__((aligned(16))); + +struct port_io_ops pio_ops; + +char *HEAP = _end; +char *heap_end = _end; /* Default end of heap = no heap */ + +/* + * Copy the header into the boot parameter block. Since this + * screws up the old-style command line protocol, adjust by + * filling in the new-style command line pointer instead. + */ +static void copy_boot_params(void) +{ + struct old_cmdline { + u16 cl_magic; + u16 cl_offset; + }; + const struct old_cmdline * const oldcmd = absolute_pointer(OLD_CL_ADDRESS); + + BUILD_BUG_ON(sizeof(boot_params) != 4096); + memcpy(&boot_params.hdr, &hdr, sizeof(hdr)); + + if (!boot_params.hdr.cmd_line_ptr && oldcmd->cl_magic == OLD_CL_MAGIC) { + /* Old-style command line protocol */ + u16 cmdline_seg; + + /* + * Figure out if the command line falls in the region + * of memory that an old kernel would have copied up + * to 0x90000... + */ + if (oldcmd->cl_offset < boot_params.hdr.setup_move_size) + cmdline_seg = ds(); + else + cmdline_seg = 0x9000; + + boot_params.hdr.cmd_line_ptr = (cmdline_seg << 4) + oldcmd->cl_offset; + } +} + +/* + * Query the keyboard lock status as given by the BIOS, and + * set the keyboard repeat rate to maximum. Unclear why the latter + * is done here; this might be possible to kill off as stale code. + */ +static void keyboard_init(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + + ireg.ah = 0x02; /* Get keyboard status */ + intcall(0x16, &ireg, &oreg); + boot_params.kbd_status = oreg.al; + + ireg.ax = 0x0305; /* Set keyboard repeat rate */ + intcall(0x16, &ireg, NULL); +} + +/* + * Get Intel SpeedStep (IST) information. + */ +static void query_ist(void) +{ + struct biosregs ireg, oreg; + + /* + * Some older BIOSes apparently crash on this call, so filter + * it from machines too old to have SpeedStep at all. + */ + if (cpu.level < 6) + return; + + initregs(&ireg); + ireg.ax = 0xe980; /* IST Support */ + ireg.edx = 0x47534943; /* Request value */ + intcall(0x15, &ireg, &oreg); + + boot_params.ist_info.signature = oreg.eax; + boot_params.ist_info.command = oreg.ebx; + boot_params.ist_info.event = oreg.ecx; + boot_params.ist_info.perf_level = oreg.edx; +} + +/* + * Tell the BIOS what CPU mode we intend to run in. + */ +static void set_bios_mode(void) +{ +#ifdef CONFIG_X86_64 + struct biosregs ireg; + + initregs(&ireg); + ireg.ax = 0xec00; + ireg.bx = 2; + intcall(0x15, &ireg, NULL); +#endif +} + +static void init_heap(void) +{ + char *stack_end; + + if (boot_params.hdr.loadflags & CAN_USE_HEAP) { + stack_end = (char *) (current_stack_pointer - STACK_SIZE); + heap_end = (char *) ((size_t)boot_params.hdr.heap_end_ptr + 0x200); + if (heap_end > stack_end) + heap_end = stack_end; + } else { + /* Boot protocol 2.00 only, no heap available */ + puts("WARNING: Ancient bootloader, some functionality may be limited!\n"); + } +} + +void main(void) +{ + init_default_io_ops(); + + /* First, copy the boot header into the "zeropage" */ + copy_boot_params(); + + /* Initialize the early-boot console */ + console_init(); + if (cmdline_find_option_bool("debug")) + puts("early console in setup code\n"); + + /* End of heap check */ + init_heap(); + + /* Make sure we have all the proper CPU support */ + if (validate_cpu()) { + puts("Unable to boot - please use a kernel appropriate for your CPU.\n"); + die(); + } + + /* Tell the BIOS what CPU mode we intend to run in */ + set_bios_mode(); + + /* Detect memory layout */ + detect_memory(); + + /* Set keyboard repeat rate (why?) and query the lock flags */ + keyboard_init(); + + /* Query Intel SpeedStep (IST) information */ + query_ist(); + + /* Query APM information */ + if (IS_ENABLED(CONFIG_APM)) + query_apm_bios(); + + /* Query EDD information */ + if (IS_ENABLED(CONFIG_EDD)) + query_edd(); + + /* Set the video mode */ + set_video(); + + /* Do the last things and invoke protected mode */ + go_to_protected_mode(); +} diff --git a/arch/x86/boot/memory.c b/arch/x86/boot/memory.c new file mode 100644 index 000000000..b0422b79d --- /dev/null +++ b/arch/x86/boot/memory.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Memory detection code + */ + +#include "boot.h" + +#define SMAP 0x534d4150 /* ASCII "SMAP" */ + +static void detect_memory_e820(void) +{ + int count = 0; + struct biosregs ireg, oreg; + struct boot_e820_entry *desc = boot_params.e820_table; + static struct boot_e820_entry buf; /* static so it is zeroed */ + + initregs(&ireg); + ireg.ax = 0xe820; + ireg.cx = sizeof(buf); + ireg.edx = SMAP; + ireg.di = (size_t)&buf; + + /* + * Note: at least one BIOS is known which assumes that the + * buffer pointed to by one e820 call is the same one as + * the previous call, and only changes modified fields. Therefore, + * we use a temporary buffer and copy the results entry by entry. + * + * This routine deliberately does not try to account for + * ACPI 3+ extended attributes. This is because there are + * BIOSes in the field which report zero for the valid bit for + * all ranges, and we don't currently make any use of the + * other attribute bits. Revisit this if we see the extended + * attribute bits deployed in a meaningful way in the future. + */ + + do { + intcall(0x15, &ireg, &oreg); + ireg.ebx = oreg.ebx; /* for next iteration... */ + + /* BIOSes which terminate the chain with CF = 1 as opposed + to %ebx = 0 don't always report the SMAP signature on + the final, failing, probe. */ + if (oreg.eflags & X86_EFLAGS_CF) + break; + + /* Some BIOSes stop returning SMAP in the middle of + the search loop. We don't know exactly how the BIOS + screwed up the map at that point, we might have a + partial map, the full map, or complete garbage, so + just return failure. */ + if (oreg.eax != SMAP) { + count = 0; + break; + } + + *desc++ = buf; + count++; + } while (ireg.ebx && count < ARRAY_SIZE(boot_params.e820_table)); + + boot_params.e820_entries = count; +} + +static void detect_memory_e801(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ax = 0xe801; + intcall(0x15, &ireg, &oreg); + + if (oreg.eflags & X86_EFLAGS_CF) + return; + + /* Do we really need to do this? */ + if (oreg.cx || oreg.dx) { + oreg.ax = oreg.cx; + oreg.bx = oreg.dx; + } + + if (oreg.ax > 15*1024) { + return; /* Bogus! */ + } else if (oreg.ax == 15*1024) { + boot_params.alt_mem_k = (oreg.bx << 6) + oreg.ax; + } else { + /* + * This ignores memory above 16MB if we have a memory + * hole there. If someone actually finds a machine + * with a memory hole at 16MB and no support for + * 0E820h they should probably generate a fake e820 + * map. + */ + boot_params.alt_mem_k = oreg.ax; + } +} + +static void detect_memory_88(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ah = 0x88; + intcall(0x15, &ireg, &oreg); + + boot_params.screen_info.ext_mem_k = oreg.ax; +} + +void detect_memory(void) +{ + detect_memory_e820(); + + detect_memory_e801(); + + detect_memory_88(); +} diff --git a/arch/x86/boot/mkcpustr.c b/arch/x86/boot/mkcpustr.c new file mode 100644 index 000000000..22d730b22 --- /dev/null +++ b/arch/x86/boot/mkcpustr.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* ----------------------------------------------------------------------- * + * + * Copyright 2008 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * This is a host program to preprocess the CPU strings into a + * compact format suitable for the setup code. + */ + +#include <stdio.h> + +#include "../include/asm/cpufeatures.h" +#include "../include/asm/vmxfeatures.h" +#include "../kernel/cpu/capflags.c" + +int main(void) +{ + int i, j; + const char *str; + + printf("#include <asm/cpufeaturemasks.h>\n\n"); + printf("static const char x86_cap_strs[] =\n"); + + for (i = 0; i < NCAPINTS; i++) { + for (j = 0; j < 32; j++) { + str = x86_cap_flags[i*32+j]; + + if (i == NCAPINTS-1 && j == 31) { + /* The last entry must be unconditional; this + also consumes the compiler-added null + character */ + if (!str) + str = ""; + printf("\t\"\\x%02x\\x%02x\"\"%s\"\n", + i, j, str); + } else if (str) { + printf("#if REQUIRED_MASK%d & (1 << %d)\n" + "\t\"\\x%02x\\x%02x\"\"%s\\0\"\n" + "#endif\n", + i, j, i, j, str); + } + } + } + printf("\t;\n"); + return 0; +} diff --git a/arch/x86/boot/mtools.conf.in b/arch/x86/boot/mtools.conf.in new file mode 100644 index 000000000..174c60508 --- /dev/null +++ b/arch/x86/boot/mtools.conf.in @@ -0,0 +1,21 @@ +# +# mtools configuration file for "make (b)zdisk" +# + +# Actual floppy drive +drive a: + file="/dev/fd0" + +# 1.44 MB floppy disk image +drive v: + file="@OBJ@/fdimage" cylinders=80 heads=2 sectors=18 filter + +# 2.88 MB floppy disk image (mostly for virtual uses) +drive w: + file="@OBJ@/fdimage" cylinders=80 heads=2 sectors=36 filter + +# Hard disk (h: for the filesystem, p: for format - old mtools bug?) +drive h: + file="@OBJ@/hdimage" offset=32768 mformat_only +drive p: + file="@OBJ@/hdimage" partition=1 mformat_only diff --git a/arch/x86/boot/pm.c b/arch/x86/boot/pm.c new file mode 100644 index 000000000..5941f930f --- /dev/null +++ b/arch/x86/boot/pm.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Prepare the machine for transition to protected mode. + */ + +#include "boot.h" +#include <asm/desc_defs.h> +#include <asm/segment.h> + +/* + * Invoke the realmode switch hook if present; otherwise + * disable all interrupts. + */ +static void realmode_switch_hook(void) +{ + if (boot_params.hdr.realmode_swtch) { + asm volatile("lcallw *%0" + : : "m" (boot_params.hdr.realmode_swtch) + : "eax", "ebx", "ecx", "edx"); + } else { + asm volatile("cli"); + outb(0x80, 0x70); /* Disable NMI */ + io_delay(); + } +} + +/* + * Disable all interrupts at the legacy PIC. + */ +static void mask_all_interrupts(void) +{ + outb(0xff, 0xa1); /* Mask all interrupts on the secondary PIC */ + io_delay(); + outb(0xfb, 0x21); /* Mask all but cascade on the primary PIC */ + io_delay(); +} + +/* + * Reset IGNNE# if asserted in the FPU. + */ +static void reset_coprocessor(void) +{ + outb(0, 0xf0); + io_delay(); + outb(0, 0xf1); + io_delay(); +} + +/* + * Set up the GDT + */ + +struct gdt_ptr { + u16 len; + u32 ptr; +} __attribute__((packed)); + +static void setup_gdt(void) +{ + /* There are machines which are known to not boot with the GDT + being 8-byte unaligned. Intel recommends 16 byte alignment. */ + static const u64 boot_gdt[] __attribute__((aligned(16))) = { + /* CS: code, read/execute, 4 GB, base 0 */ + [GDT_ENTRY_BOOT_CS] = GDT_ENTRY(DESC_CODE32, 0, 0xfffff), + /* DS: data, read/write, 4 GB, base 0 */ + [GDT_ENTRY_BOOT_DS] = GDT_ENTRY(DESC_DATA32, 0, 0xfffff), + /* TSS: 32-bit tss, 104 bytes, base 4096 */ + /* We only have a TSS here to keep Intel VT happy; + we don't actually use it for anything. */ + [GDT_ENTRY_BOOT_TSS] = GDT_ENTRY(DESC_TSS32, 4096, 103), + }; + /* Xen HVM incorrectly stores a pointer to the gdt_ptr, instead + of the gdt_ptr contents. Thus, make it static so it will + stay in memory, at least long enough that we switch to the + proper kernel GDT. */ + static struct gdt_ptr gdt; + + gdt.len = sizeof(boot_gdt)-1; + gdt.ptr = (u32)&boot_gdt + (ds() << 4); + + asm volatile("lgdtl %0" : : "m" (gdt)); +} + +/* + * Set up the IDT + */ +static void setup_idt(void) +{ + static const struct gdt_ptr null_idt = {0, 0}; + asm volatile("lidtl %0" : : "m" (null_idt)); +} + +/* + * Actual invocation sequence + */ +void go_to_protected_mode(void) +{ + /* Hook before leaving real mode, also disables interrupts */ + realmode_switch_hook(); + + /* Enable the A20 gate */ + if (enable_a20()) { + puts("A20 gate not responding, unable to boot...\n"); + die(); + } + + /* Reset coprocessor (IGNNE#) */ + reset_coprocessor(); + + /* Mask all interrupts in the PIC */ + mask_all_interrupts(); + + /* Actual transition to protected mode... */ + setup_idt(); + setup_gdt(); + protected_mode_jump(boot_params.hdr.code32_start, + (u32)&boot_params + (ds() << 4)); +} diff --git a/arch/x86/boot/pmjump.S b/arch/x86/boot/pmjump.S new file mode 100644 index 000000000..cbec8bd08 --- /dev/null +++ b/arch/x86/boot/pmjump.S @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* ----------------------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * The actual transition into protected mode + */ + +#include <asm/boot.h> +#include <asm/processor-flags.h> +#include <asm/segment.h> +#include <linux/linkage.h> + + .text + .code16 + +/* + * void protected_mode_jump(u32 entrypoint, u32 bootparams); + */ +SYM_FUNC_START_NOALIGN(protected_mode_jump) + movl %edx, %esi # Pointer to boot_params table + + xorl %ebx, %ebx + movw %cs, %bx + shll $4, %ebx + addl %ebx, 2f + jmp 1f # Short jump to serialize on 386/486 +1: + + movw $__BOOT_DS, %cx + movw $__BOOT_TSS, %di + + movl %cr0, %edx + orb $X86_CR0_PE, %dl # Protected mode + movl %edx, %cr0 + + # Transition to 32-bit mode + .byte 0x66, 0xea # ljmpl opcode +2: .long .Lin_pm32 # offset + .word __BOOT_CS # segment +SYM_FUNC_END(protected_mode_jump) + + .code32 + .section ".text32","ax" +SYM_FUNC_START_LOCAL_NOALIGN(.Lin_pm32) + # Set up data segments for flat 32-bit mode + movl %ecx, %ds + movl %ecx, %es + movl %ecx, %fs + movl %ecx, %gs + movl %ecx, %ss + # The 32-bit code sets up its own stack, but this way we do have + # a valid stack if some debugging hack wants to use it. + addl %ebx, %esp + + # Set up TR to make Intel VT happy + ltr %di + + # Clear registers to allow for future extensions to the + # 32-bit boot protocol + xorl %ecx, %ecx + xorl %edx, %edx + xorl %ebx, %ebx + xorl %ebp, %ebp + xorl %edi, %edi + + # Set up LDTR to make Intel VT happy + lldt %cx + + jmpl *%eax # Jump to the 32-bit entrypoint +SYM_FUNC_END(.Lin_pm32) diff --git a/arch/x86/boot/printf.c b/arch/x86/boot/printf.c new file mode 100644 index 000000000..51dc14b71 --- /dev/null +++ b/arch/x86/boot/printf.c @@ -0,0 +1,310 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Oh, it's a waste of space, but oh-so-yummy for debugging. This + * version of printf() does not include 64-bit support. "Live with + * it." + * + */ + +#include "boot.h" + +static int skip_atoi(const char **s) +{ + int i = 0; + + while (isdigit(**s)) + i = i * 10 + *((*s)++) - '0'; + return i; +} + +#define ZEROPAD 1 /* pad with zero */ +#define SIGN 2 /* unsigned/signed long */ +#define PLUS 4 /* show plus */ +#define SPACE 8 /* space if plus */ +#define LEFT 16 /* left justified */ +#define SMALL 32 /* Must be 32 == 0x20 */ +#define SPECIAL 64 /* 0x */ + +#define __do_div(n, base) ({ \ +int __res; \ +__res = ((unsigned long) n) % (unsigned) base; \ +n = ((unsigned long) n) / (unsigned) base; \ +__res; }) + +static char *number(char *str, long num, int base, int size, int precision, + int type) +{ + /* we are called with base 8, 10 or 16, only, thus don't need "G..." */ + static const char digits[16] = "0123456789ABCDEF"; /* "GHIJKLMNOPQRSTUVWXYZ"; */ + + char tmp[66]; + char c, sign, locase; + int i; + + /* locase = 0 or 0x20. ORing digits or letters with 'locase' + * produces same digits or (maybe lowercased) letters */ + locase = (type & SMALL); + if (type & LEFT) + type &= ~ZEROPAD; + if (base < 2 || base > 16) + return NULL; + c = (type & ZEROPAD) ? '0' : ' '; + sign = 0; + if (type & SIGN) { + if (num < 0) { + sign = '-'; + num = -num; + size--; + } else if (type & PLUS) { + sign = '+'; + size--; + } else if (type & SPACE) { + sign = ' '; + size--; + } + } + if (type & SPECIAL) { + if (base == 16) + size -= 2; + else if (base == 8) + size--; + } + i = 0; + if (num == 0) + tmp[i++] = '0'; + else + while (num != 0) + tmp[i++] = (digits[__do_div(num, base)] | locase); + if (i > precision) + precision = i; + size -= precision; + if (!(type & (ZEROPAD + LEFT))) + while (size-- > 0) + *str++ = ' '; + if (sign) + *str++ = sign; + if (type & SPECIAL) { + if (base == 8) + *str++ = '0'; + else if (base == 16) { + *str++ = '0'; + *str++ = ('X' | locase); + } + } + if (!(type & LEFT)) + while (size-- > 0) + *str++ = c; + while (i < precision--) + *str++ = '0'; + while (i-- > 0) + *str++ = tmp[i]; + while (size-- > 0) + *str++ = ' '; + return str; +} + +int vsprintf(char *buf, const char *fmt, va_list args) +{ + int len; + unsigned long num; + int i, base; + char *str; + const char *s; + + int flags; /* flags to number() */ + + int field_width; /* width of output field */ + int precision; /* min. # of digits for integers; max + number of chars for from string */ + int qualifier; /* 'h', 'l', or 'L' for integer fields */ + + for (str = buf; *fmt; ++fmt) { + if (*fmt != '%') { + *str++ = *fmt; + continue; + } + + /* process flags */ + flags = 0; + repeat: + ++fmt; /* this also skips first '%' */ + switch (*fmt) { + case '-': + flags |= LEFT; + goto repeat; + case '+': + flags |= PLUS; + goto repeat; + case ' ': + flags |= SPACE; + goto repeat; + case '#': + flags |= SPECIAL; + goto repeat; + case '0': + flags |= ZEROPAD; + goto repeat; + } + + /* get field width */ + field_width = -1; + if (isdigit(*fmt)) + field_width = skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + field_width = va_arg(args, int); + if (field_width < 0) { + field_width = -field_width; + flags |= LEFT; + } + } + + /* get the precision */ + precision = -1; + if (*fmt == '.') { + ++fmt; + if (isdigit(*fmt)) + precision = skip_atoi(&fmt); + else if (*fmt == '*') { + ++fmt; + /* it's the next argument */ + precision = va_arg(args, int); + } + if (precision < 0) + precision = 0; + } + + /* get the conversion qualifier */ + qualifier = -1; + if (*fmt == 'h' || *fmt == 'l' || *fmt == 'L') { + qualifier = *fmt; + ++fmt; + } + + /* default base */ + base = 10; + + switch (*fmt) { + case 'c': + if (!(flags & LEFT)) + while (--field_width > 0) + *str++ = ' '; + *str++ = (unsigned char)va_arg(args, int); + while (--field_width > 0) + *str++ = ' '; + continue; + + case 's': + s = va_arg(args, char *); + len = strnlen(s, precision); + + if (!(flags & LEFT)) + while (len < field_width--) + *str++ = ' '; + for (i = 0; i < len; ++i) + *str++ = *s++; + while (len < field_width--) + *str++ = ' '; + continue; + + case 'p': + if (field_width == -1) { + field_width = 2 * sizeof(void *); + flags |= ZEROPAD; + } + str = number(str, + (unsigned long)va_arg(args, void *), 16, + field_width, precision, flags); + continue; + + case 'n': + if (qualifier == 'l') { + long *ip = va_arg(args, long *); + *ip = (str - buf); + } else { + int *ip = va_arg(args, int *); + *ip = (str - buf); + } + continue; + + case '%': + *str++ = '%'; + continue; + + /* integer number formats - set up the flags and "break" */ + case 'o': + base = 8; + break; + + case 'x': + flags |= SMALL; + fallthrough; + case 'X': + base = 16; + break; + + case 'd': + case 'i': + flags |= SIGN; + break; + + case 'u': + break; + + default: + *str++ = '%'; + if (*fmt) + *str++ = *fmt; + else + --fmt; + continue; + } + if (qualifier == 'l') + num = va_arg(args, unsigned long); + else if (qualifier == 'h') { + num = (unsigned short)va_arg(args, int); + if (flags & SIGN) + num = (short)num; + } else if (flags & SIGN) + num = va_arg(args, int); + else + num = va_arg(args, unsigned int); + str = number(str, num, base, field_width, precision, flags); + } + *str = '\0'; + return str - buf; +} + +int sprintf(char *buf, const char *fmt, ...) +{ + va_list args; + int i; + + va_start(args, fmt); + i = vsprintf(buf, fmt, args); + va_end(args); + return i; +} + +int printf(const char *fmt, ...) +{ + char printf_buf[1024]; + va_list args; + int printed; + + va_start(args, fmt); + printed = vsprintf(printf_buf, fmt, args); + va_end(args); + + puts(printf_buf); + + return printed; +} diff --git a/arch/x86/boot/regs.c b/arch/x86/boot/regs.c new file mode 100644 index 000000000..55de6b309 --- /dev/null +++ b/arch/x86/boot/regs.c @@ -0,0 +1,27 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* ----------------------------------------------------------------------- + * + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Simple helper function for initializing a register set. + * + * Note that this sets EFLAGS_CF in the input register set; this + * makes it easier to catch functions which do nothing but don't + * explicitly set CF. + */ + +#include "boot.h" +#include "string.h" + +void initregs(struct biosregs *reg) +{ + memset(reg, 0, sizeof(*reg)); + reg->eflags |= X86_EFLAGS_CF; + reg->ds = ds(); + reg->es = ds(); + reg->fs = fs(); + reg->gs = gs(); +} diff --git a/arch/x86/boot/setup.ld b/arch/x86/boot/setup.ld new file mode 100644 index 000000000..e1d594a60 --- /dev/null +++ b/arch/x86/boot/setup.ld @@ -0,0 +1,74 @@ +/* + * setup.ld + * + * Linker script for the i386 setup code + */ +OUTPUT_FORMAT("elf32-i386") +OUTPUT_ARCH(i386) +ENTRY(_start) + +SECTIONS +{ + . = 0; + .bstext : { + *(.bstext) + . = 495; + } =0xffffffff + + .header : { *(.header) } + .entrytext : { *(.entrytext) } + .inittext : { *(.inittext) } + .initdata : { *(.initdata) } + __end_init = .; + + .text : { *(.text .text.*) } + .text32 : { *(.text32) } + + .pecompat : { *(.pecompat) } + PROVIDE(pecompat_fsize = setup_size - pecompat_fstart); + + . = ALIGN(16); + .rodata : { *(.rodata*) } + + .videocards : { + video_cards = .; + *(.videocards) + video_cards_end = .; + } + + . = ALIGN(16); + .data : { *(.data*) } + + .signature : { + setup_sig = .; + LONG(0x5a5aaa55) + + setup_size = ALIGN(ABSOLUTE(.), 4096); + setup_sects = ABSOLUTE(setup_size / 512); + ASSERT(setup_sects >= 5, "The setup must be at least 5 sectors in size"); + ASSERT(setup_sects <= 64, "The setup must be at most 64 sectors in size"); + } + + . = ALIGN(16); + .bss : + { + __bss_start = .; + *(.bss) + __bss_end = .; + } + . = ALIGN(16); + _end = .; + + /DISCARD/ : { + *(.note*) + } + + /* + * The ASSERT() sink to . is intentional, for binutils 2.14 compatibility: + */ + . = ASSERT(_end <= 0x8000, "Setup too big!"); + . = ASSERT(hdr == 0x1f1, "The setup header has the wrong offset!"); + /* Necessary for the very-old-loader check to work... */ + . = ASSERT(__end_init <= 5*512, "init sections too big!"); + +} diff --git a/arch/x86/boot/startup/Makefile b/arch/x86/boot/startup/Makefile new file mode 100644 index 000000000..5e499cfb2 --- /dev/null +++ b/arch/x86/boot/startup/Makefile @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: GPL-2.0 + +KBUILD_AFLAGS += -D__DISABLE_EXPORTS +KBUILD_CFLAGS += -D__DISABLE_EXPORTS -mcmodel=small -fPIC \ + -Os -DDISABLE_BRANCH_PROFILING \ + $(DISABLE_STACKLEAK_PLUGIN) \ + $(DISABLE_LATENT_ENTROPY_PLUGIN) \ + -fno-stack-protector -D__NO_FORTIFY \ + -fno-jump-tables \ + -include $(srctree)/include/linux/hidden.h + +# disable ftrace hooks and LTO +KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) +KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO),$(KBUILD_CFLAGS)) +KASAN_SANITIZE := n +KCSAN_SANITIZE := n +KMSAN_SANITIZE := n +UBSAN_SANITIZE := n +KCOV_INSTRUMENT := n + +obj-$(CONFIG_X86_64) += gdt_idt.o map_kernel.o +obj-$(CONFIG_AMD_MEM_ENCRYPT) += sme.o sev-startup.o +pi-objs := $(patsubst %.o,$(obj)/%.o,$(obj-y)) + +lib-$(CONFIG_X86_64) += la57toggle.o +lib-$(CONFIG_EFI_MIXED) += efi-mixed.o + +# +# Disable objtool validation for all library code, which is intended +# to be linked into the decompressor or the EFI stub but not vmlinux +# +$(patsubst %.o,$(obj)/%.o,$(lib-y)): OBJECT_FILES_NON_STANDARD := y + +# +# Invoke objtool for each object individually to check for absolute +# relocations, even if other objtool actions are being deferred. +# +$(pi-objs): objtool-enabled = 1 +$(pi-objs): objtool-args = $(if $(delay-objtool),--dry-run,$(objtool-args-y)) --noabs + +# +# Confine the startup code by prefixing all symbols with __pi_ (for position +# independent). This ensures that startup code can only call other startup +# code, or code that has explicitly been made accessible to it via a symbol +# alias. +# +$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ +$(obj)/%.pi.o: $(obj)/%.o FORCE + $(call if_changed,objcopy) + +targets += $(obj-y) +obj-y := $(patsubst %.o,%.pi.o,$(obj-y)) diff --git a/arch/x86/boot/startup/efi-mixed.S b/arch/x86/boot/startup/efi-mixed.S new file mode 100644 index 000000000..e04ed99bc --- /dev/null +++ b/arch/x86/boot/startup/efi-mixed.S @@ -0,0 +1,253 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2014, 2015 Intel Corporation; author Matt Fleming + * + * Early support for invoking 32-bit EFI services from a 64-bit kernel. + * + * Because this thunking occurs before ExitBootServices() we have to + * restore the firmware's 32-bit GDT and IDT before we make EFI service + * calls. + * + * On the plus side, we don't have to worry about mangling 64-bit + * addresses into 32-bits because we're executing with an identity + * mapped pagetable and haven't transitioned to 64-bit virtual addresses + * yet. + */ + +#include <linux/linkage.h> +#include <asm/desc_defs.h> +#include <asm/msr.h> +#include <asm/page_types.h> +#include <asm/pgtable_types.h> +#include <asm/processor-flags.h> +#include <asm/segment.h> + + .text + .code32 +#ifdef CONFIG_EFI_HANDOVER_PROTOCOL +SYM_FUNC_START(efi32_stub_entry) + call 1f +1: popl %ecx + + /* Clear BSS */ + xorl %eax, %eax + leal (_bss - 1b)(%ecx), %edi + leal (_ebss - 1b)(%ecx), %ecx + subl %edi, %ecx + shrl $2, %ecx + cld + rep stosl + + add $0x4, %esp /* Discard return address */ + movl 8(%esp), %ebx /* struct boot_params pointer */ + jmp efi32_startup +SYM_FUNC_END(efi32_stub_entry) +#endif + +/* + * Called using a far call from __efi64_thunk() below, using the x86_64 SysV + * ABI (except for R8/R9 which are inaccessible to 32-bit code - EAX/EBX are + * used instead). EBP+16 points to the arguments passed via the stack. + * + * The first argument (EDI) is a pointer to the boot service or protocol, to + * which the remaining arguments are passed, each truncated to 32 bits. + */ +SYM_FUNC_START_LOCAL(efi_enter32) + /* + * Convert x86-64 SysV ABI params to i386 ABI + */ + pushl 32(%ebp) /* Up to 3 args passed via the stack */ + pushl 24(%ebp) + pushl 16(%ebp) + pushl %ebx /* R9 */ + pushl %eax /* R8 */ + pushl %ecx + pushl %edx + pushl %esi + + /* Disable paging */ + movl %cr0, %eax + btrl $X86_CR0_PG_BIT, %eax + movl %eax, %cr0 + + /* Disable long mode via EFER */ + movl $MSR_EFER, %ecx + rdmsr + btrl $_EFER_LME, %eax + wrmsr + + call *%edi + + /* We must preserve return value */ + movl %eax, %edi + + call efi32_enable_long_mode + + addl $32, %esp + movl %edi, %eax + lret +SYM_FUNC_END(efi_enter32) + + .code64 +SYM_FUNC_START(__efi64_thunk) + push %rbp + movl %esp, %ebp + push %rbx + + /* Move args #5 and #6 into 32-bit accessible registers */ + movl %r8d, %eax + movl %r9d, %ebx + + lcalll *efi32_call(%rip) + + pop %rbx + pop %rbp + RET +SYM_FUNC_END(__efi64_thunk) + + .code32 +SYM_FUNC_START_LOCAL(efi32_enable_long_mode) + movl %cr4, %eax + btsl $(X86_CR4_PAE_BIT), %eax + movl %eax, %cr4 + + movl $MSR_EFER, %ecx + rdmsr + btsl $_EFER_LME, %eax + wrmsr + + /* Disable interrupts - the firmware's IDT does not work in long mode */ + cli + + /* Enable paging */ + movl %cr0, %eax + btsl $X86_CR0_PG_BIT, %eax + movl %eax, %cr0 + ret +SYM_FUNC_END(efi32_enable_long_mode) + +/* + * This is the common EFI stub entry point for mixed mode. It sets up the GDT + * and page tables needed for 64-bit execution, after which it calls the + * common 64-bit EFI entrypoint efi_stub_entry(). + * + * Arguments: 0(%esp) image handle + * 4(%esp) EFI system table pointer + * %ebx struct boot_params pointer (or NULL) + * + * Since this is the point of no return for ordinary execution, no registers + * are considered live except for the function parameters. [Note that the EFI + * stub may still exit and return to the firmware using the Exit() EFI boot + * service.] + */ +SYM_FUNC_START_LOCAL(efi32_startup) + movl %esp, %ebp + + subl $8, %esp + sgdtl (%esp) /* Save GDT descriptor to the stack */ + movl 2(%esp), %esi /* Existing GDT pointer */ + movzwl (%esp), %ecx /* Existing GDT limit */ + inc %ecx /* Existing GDT size */ + andl $~7, %ecx /* Ensure size is multiple of 8 */ + + subl %ecx, %esp /* Allocate new GDT */ + andl $~15, %esp /* Realign the stack */ + movl %esp, %edi /* New GDT address */ + leal 7(%ecx), %eax /* New GDT limit */ + pushw %cx /* Push 64-bit CS (for LJMP below) */ + pushl %edi /* Push new GDT address */ + pushw %ax /* Push new GDT limit */ + + /* Copy GDT to the stack and add a 64-bit code segment at the end */ + movl $GDT_ENTRY(DESC_CODE64, 0, 0xfffff) & 0xffffffff, (%edi,%ecx) + movl $GDT_ENTRY(DESC_CODE64, 0, 0xfffff) >> 32, 4(%edi,%ecx) + shrl $2, %ecx + cld + rep movsl /* Copy the firmware GDT */ + lgdtl (%esp) /* Switch to the new GDT */ + + call 1f +1: pop %edi + + /* Record mixed mode entry */ + movb $0x0, (efi_is64 - 1b)(%edi) + + /* Set up indirect far call to re-enter 32-bit mode */ + leal (efi32_call - 1b)(%edi), %eax + addl %eax, (%eax) + movw %cs, 4(%eax) + + /* Disable paging */ + movl %cr0, %eax + btrl $X86_CR0_PG_BIT, %eax + movl %eax, %cr0 + + /* Set up 1:1 mapping */ + leal (pte - 1b)(%edi), %eax + movl $_PAGE_PRESENT | _PAGE_RW | _PAGE_PSE, %ecx + leal (_PAGE_PRESENT | _PAGE_RW)(%eax), %edx +2: movl %ecx, (%eax) + addl $8, %eax + addl $PMD_SIZE, %ecx + jnc 2b + + movl $PAGE_SIZE, %ecx + .irpc l, 0123 + movl %edx, \l * 8(%eax) + addl %ecx, %edx + .endr + addl %ecx, %eax + movl %edx, (%eax) + movl %eax, %cr3 + + call efi32_enable_long_mode + + /* Set up far jump to 64-bit mode (CS is already on the stack) */ + leal (efi_stub_entry - 1b)(%edi), %eax + movl %eax, 2(%esp) + + movl 0(%ebp), %edi + movl 4(%ebp), %esi + movl %ebx, %edx + ljmpl *2(%esp) +SYM_FUNC_END(efi32_startup) + +/* + * efi_status_t efi32_pe_entry(efi_handle_t image_handle, + * efi_system_table_32_t *sys_table) + */ +SYM_FUNC_START(efi32_pe_entry) + pushl %ebx // save callee-save registers + + /* Check whether the CPU supports long mode */ + movl $0x80000001, %eax // assume extended info support + cpuid + btl $29, %edx // check long mode bit + jnc 1f + leal 8(%esp), %esp // preserve stack alignment + xor %ebx, %ebx // no struct boot_params pointer + jmp efi32_startup // only ESP and EBX remain live +1: movl $0x80000003, %eax // EFI_UNSUPPORTED + popl %ebx + RET +SYM_FUNC_END(efi32_pe_entry) + +#ifdef CONFIG_EFI_HANDOVER_PROTOCOL + .org efi32_stub_entry + 0x200 + .code64 +SYM_FUNC_START_NOALIGN(efi64_stub_entry) + jmp efi_handover_entry +SYM_FUNC_END(efi64_stub_entry) +#endif + + .data + .balign 8 +SYM_DATA_START_LOCAL(efi32_call) + .long efi_enter32 - . + .word 0x0 +SYM_DATA_END(efi32_call) +SYM_DATA(efi_is64, .byte 1) + + .bss + .balign PAGE_SIZE +SYM_DATA_LOCAL(pte, .fill 6 * PAGE_SIZE, 1, 0) diff --git a/arch/x86/boot/startup/exports.h b/arch/x86/boot/startup/exports.h new file mode 100644 index 000000000..01d2363dc --- /dev/null +++ b/arch/x86/boot/startup/exports.h @@ -0,0 +1,14 @@ + +/* + * The symbols below are functions that are implemented by the startup code, + * but called at runtime by the SEV code residing in the core kernel. + */ +PROVIDE(early_set_pages_state = __pi_early_set_pages_state); +PROVIDE(early_snp_set_memory_private = __pi_early_snp_set_memory_private); +PROVIDE(early_snp_set_memory_shared = __pi_early_snp_set_memory_shared); +PROVIDE(get_hv_features = __pi_get_hv_features); +PROVIDE(sev_es_terminate = __pi_sev_es_terminate); +PROVIDE(snp_cpuid = __pi_snp_cpuid); +PROVIDE(snp_cpuid_get_table = __pi_snp_cpuid_get_table); +PROVIDE(svsm_issue_call = __pi_svsm_issue_call); +PROVIDE(svsm_process_result_codes = __pi_svsm_process_result_codes); diff --git a/arch/x86/boot/startup/gdt_idt.c b/arch/x86/boot/startup/gdt_idt.c new file mode 100644 index 000000000..d16102abd --- /dev/null +++ b/arch/x86/boot/startup/gdt_idt.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/linkage.h> +#include <linux/types.h> + +#include <asm/desc.h> +#include <asm/init.h> +#include <asm/setup.h> +#include <asm/sev.h> +#include <asm/trapnr.h> + +/* + * Data structures and code used for IDT setup in head_64.S. The bringup-IDT is + * used until the idt_table takes over. On the boot CPU this happens in + * x86_64_start_kernel(), on secondary CPUs in start_secondary(). In both cases + * this happens in the functions called from head_64.S. + * + * The idt_table can't be used that early because all the code modifying it is + * in idt.c and can be instrumented by tracing or KASAN, which both don't work + * during early CPU bringup. Also the idt_table has the runtime vectors + * configured which require certain CPU state to be setup already (like TSS), + * which also hasn't happened yet in early CPU bringup. + */ +static gate_desc bringup_idt_table[NUM_EXCEPTION_VECTORS] __page_aligned_data; + +/* This may run while still in the direct mapping */ +void startup_64_load_idt(void *vc_handler) +{ + struct desc_ptr desc = { + .address = (unsigned long)rip_rel_ptr(bringup_idt_table), + .size = sizeof(bringup_idt_table) - 1, + }; + struct idt_data data; + gate_desc idt_desc; + + /* @vc_handler is set only for a VMM Communication Exception */ + if (vc_handler) { + init_idt_data(&data, X86_TRAP_VC, vc_handler); + idt_init_desc(&idt_desc, &data); + native_write_idt_entry((gate_desc *)desc.address, X86_TRAP_VC, &idt_desc); + } + + native_load_idt(&desc); +} + +/* + * Setup boot CPU state needed before kernel switches to virtual addresses. + */ +void __init startup_64_setup_gdt_idt(void) +{ + struct gdt_page *gp = rip_rel_ptr((void *)(__force unsigned long)&gdt_page); + void *handler = NULL; + + struct desc_ptr startup_gdt_descr = { + .address = (unsigned long)gp->gdt, + .size = GDT_SIZE - 1, + }; + + /* Load GDT */ + native_load_gdt(&startup_gdt_descr); + + /* New GDT is live - reload data segment registers */ + asm volatile("movl %%eax, %%ds\n" + "movl %%eax, %%ss\n" + "movl %%eax, %%es\n" : : "a"(__KERNEL_DS) : "memory"); + + if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) + handler = rip_rel_ptr(vc_no_ghcb); + + startup_64_load_idt(handler); +} diff --git a/arch/x86/boot/startup/la57toggle.S b/arch/x86/boot/startup/la57toggle.S new file mode 100644 index 000000000..370075b4d --- /dev/null +++ b/arch/x86/boot/startup/la57toggle.S @@ -0,0 +1,111 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#include <linux/linkage.h> +#include <asm/segment.h> +#include <asm/boot.h> +#include <asm/msr.h> +#include <asm/processor-flags.h> + +/* + * This is the 32-bit trampoline that will be copied over to low memory. It + * will be called using the ordinary 64-bit calling convention from code + * running in 64-bit mode. + * + * Return address is at the top of the stack (might be above 4G). + * The first argument (EDI) contains the address of the temporary PGD level + * page table in 32-bit addressable memory which will be programmed into + * register CR3. + */ + + .section ".rodata", "a", @progbits +SYM_CODE_START(trampoline_32bit_src) + /* + * Preserve callee save 64-bit registers on the stack: this is + * necessary because the architecture does not guarantee that GPRs will + * retain their full 64-bit values across a 32-bit mode switch. + */ + pushq %r15 + pushq %r14 + pushq %r13 + pushq %r12 + pushq %rbp + pushq %rbx + + /* Preserve top half of RSP in a legacy mode GPR to avoid truncation */ + movq %rsp, %rbx + shrq $32, %rbx + + /* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */ + pushq $__KERNEL32_CS + leaq 0f(%rip), %rax + pushq %rax + lretq + + /* + * The 32-bit code below will do a far jump back to long mode and end + * up here after reconfiguring the number of paging levels. First, the + * stack pointer needs to be restored to its full 64-bit value before + * the callee save register contents can be popped from the stack. + */ +.Lret: + shlq $32, %rbx + orq %rbx, %rsp + + /* Restore the preserved 64-bit registers */ + popq %rbx + popq %rbp + popq %r12 + popq %r13 + popq %r14 + popq %r15 + retq + + .code32 +0: + /* Disable paging */ + movl %cr0, %eax + btrl $X86_CR0_PG_BIT, %eax + movl %eax, %cr0 + + /* Point CR3 to the trampoline's new top level page table */ + movl %edi, %cr3 + + /* Set EFER.LME=1 as a precaution in case hypervsior pulls the rug */ + movl $MSR_EFER, %ecx + rdmsr + btsl $_EFER_LME, %eax + /* Avoid writing EFER if no change was made (for TDX guest) */ + jc 1f + wrmsr +1: + /* Toggle CR4.LA57 */ + movl %cr4, %eax + btcl $X86_CR4_LA57_BIT, %eax + movl %eax, %cr4 + + /* Enable paging again. */ + movl %cr0, %eax + btsl $X86_CR0_PG_BIT, %eax + movl %eax, %cr0 + + /* + * Return to the 64-bit calling code using LJMP rather than LRET, to + * avoid the need for a 32-bit addressable stack. The destination + * address will be adjusted after the template code is copied into a + * 32-bit addressable buffer. + */ +.Ljmp: ljmpl $__KERNEL_CS, $(.Lret - trampoline_32bit_src) +SYM_CODE_END(trampoline_32bit_src) + +/* + * This symbol is placed right after trampoline_32bit_src() so its address can + * be used to infer the size of the trampoline code. + */ +SYM_DATA(trampoline_ljmp_imm_offset, .word .Ljmp + 1 - trampoline_32bit_src) + + /* + * The trampoline code has a size limit. + * Make sure we fail to compile if the trampoline code grows + * beyond TRAMPOLINE_32BIT_CODE_SIZE bytes. + */ + .org trampoline_32bit_src + TRAMPOLINE_32BIT_CODE_SIZE diff --git a/arch/x86/boot/startup/map_kernel.c b/arch/x86/boot/startup/map_kernel.c new file mode 100644 index 000000000..83ba98d61 --- /dev/null +++ b/arch/x86/boot/startup/map_kernel.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/pgtable.h> + +#include <asm/init.h> +#include <asm/sections.h> +#include <asm/setup.h> +#include <asm/sev.h> + +extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD]; +extern unsigned int next_early_pgt; + +static inline bool check_la57_support(void) +{ + /* + * 5-level paging is detected and enabled at kernel decompression + * stage. Only check if it has been enabled there. + */ + if (!(native_read_cr4() & X86_CR4_LA57)) + return false; + + __pgtable_l5_enabled = 1; + pgdir_shift = 48; + ptrs_per_p4d = 512; + + return true; +} + +static unsigned long __init sme_postprocess_startup(struct boot_params *bp, + pmdval_t *pmd, + unsigned long p2v_offset) +{ + unsigned long paddr, paddr_end; + int i; + + /* Encrypt the kernel and related (if SME is active) */ + sme_encrypt_kernel(bp); + + /* + * Clear the memory encryption mask from the .bss..decrypted section. + * The bss section will be memset to zero later in the initialization so + * there is no need to zero it after changing the memory encryption + * attribute. + */ + if (sme_get_me_mask()) { + paddr = (unsigned long)rip_rel_ptr(__start_bss_decrypted); + paddr_end = (unsigned long)rip_rel_ptr(__end_bss_decrypted); + + for (; paddr < paddr_end; paddr += PMD_SIZE) { + /* + * On SNP, transition the page to shared in the RMP table so that + * it is consistent with the page table attribute change. + * + * __start_bss_decrypted has a virtual address in the high range + * mapping (kernel .text). PVALIDATE, by way of + * early_snp_set_memory_shared(), requires a valid virtual + * address but the kernel is currently running off of the identity + * mapping so use the PA to get a *currently* valid virtual address. + */ + early_snp_set_memory_shared(paddr, paddr, PTRS_PER_PMD); + + i = pmd_index(paddr - p2v_offset); + pmd[i] -= sme_get_me_mask(); + } + } + + /* + * Return the SME encryption mask (if SME is active) to be used as a + * modifier for the initial pgdir entry programmed into CR3. + */ + return sme_get_me_mask(); +} + +/* + * This code is compiled using PIC codegen because it will execute from the + * early 1:1 mapping of memory, which deviates from the mapping expected by the + * linker. Due to this deviation, taking the address of a global variable will + * produce an ambiguous result when using the plain & operator. Instead, + * rip_rel_ptr() must be used, which will return the RIP-relative address in + * the 1:1 mapping of memory. Kernel virtual addresses can be determined by + * subtracting p2v_offset from the RIP-relative address. + */ +unsigned long __init __startup_64(unsigned long p2v_offset, + struct boot_params *bp) +{ + pmd_t (*early_pgts)[PTRS_PER_PMD] = rip_rel_ptr(early_dynamic_pgts); + unsigned long physaddr = (unsigned long)rip_rel_ptr(_text); + unsigned long va_text, va_end; + unsigned long pgtable_flags; + unsigned long load_delta; + pgdval_t *pgd; + p4dval_t *p4d; + pudval_t *pud; + pmdval_t *pmd, pmd_entry; + bool la57; + int i; + + la57 = check_la57_support(); + + /* Is the address too large? */ + if (physaddr >> MAX_PHYSMEM_BITS) + for (;;); + + /* + * Compute the delta between the address I am compiled to run at + * and the address I am actually running at. + */ + phys_base = load_delta = __START_KERNEL_map + p2v_offset; + + /* Is the address not 2M aligned? */ + if (load_delta & ~PMD_MASK) + for (;;); + + va_text = physaddr - p2v_offset; + va_end = (unsigned long)rip_rel_ptr(_end) - p2v_offset; + + /* Include the SME encryption mask in the fixup value */ + load_delta += sme_get_me_mask(); + + /* Fixup the physical addresses in the page table */ + + pgd = rip_rel_ptr(early_top_pgt); + pgd[pgd_index(__START_KERNEL_map)] += load_delta; + + if (la57) { + p4d = (p4dval_t *)rip_rel_ptr(level4_kernel_pgt); + p4d[MAX_PTRS_PER_P4D - 1] += load_delta; + + pgd[pgd_index(__START_KERNEL_map)] = (pgdval_t)p4d | _PAGE_TABLE; + } + + level3_kernel_pgt[PTRS_PER_PUD - 2].pud += load_delta; + level3_kernel_pgt[PTRS_PER_PUD - 1].pud += load_delta; + + for (i = FIXMAP_PMD_TOP; i > FIXMAP_PMD_TOP - FIXMAP_PMD_NUM; i--) + level2_fixmap_pgt[i].pmd += load_delta; + + /* + * Set up the identity mapping for the switchover. These + * entries should *NOT* have the global bit set! This also + * creates a bunch of nonsense entries but that is fine -- + * it avoids problems around wraparound. + */ + + pud = &early_pgts[0]->pmd; + pmd = &early_pgts[1]->pmd; + next_early_pgt = 2; + + pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask(); + + if (la57) { + p4d = &early_pgts[next_early_pgt++]->pmd; + + i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; + pgd[i + 0] = (pgdval_t)p4d + pgtable_flags; + pgd[i + 1] = (pgdval_t)p4d + pgtable_flags; + + i = physaddr >> P4D_SHIFT; + p4d[(i + 0) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags; + p4d[(i + 1) % PTRS_PER_P4D] = (pgdval_t)pud + pgtable_flags; + } else { + i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD; + pgd[i + 0] = (pgdval_t)pud + pgtable_flags; + pgd[i + 1] = (pgdval_t)pud + pgtable_flags; + } + + i = physaddr >> PUD_SHIFT; + pud[(i + 0) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags; + pud[(i + 1) % PTRS_PER_PUD] = (pudval_t)pmd + pgtable_flags; + + pmd_entry = __PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL; + pmd_entry += sme_get_me_mask(); + pmd_entry += physaddr; + + for (i = 0; i < DIV_ROUND_UP(va_end - va_text, PMD_SIZE); i++) { + int idx = i + (physaddr >> PMD_SHIFT); + + pmd[idx % PTRS_PER_PMD] = pmd_entry + i * PMD_SIZE; + } + + /* + * Fixup the kernel text+data virtual addresses. Note that + * we might write invalid pmds, when the kernel is relocated + * cleanup_highmap() fixes this up along with the mappings + * beyond _end. + * + * Only the region occupied by the kernel image has so far + * been checked against the table of usable memory regions + * provided by the firmware, so invalidate pages outside that + * region. A page table entry that maps to a reserved area of + * memory would allow processor speculation into that area, + * and on some hardware (particularly the UV platform) even + * speculative access to some reserved areas is caught as an + * error, causing the BIOS to halt the system. + */ + + pmd = rip_rel_ptr(level2_kernel_pgt); + + /* invalidate pages before the kernel image */ + for (i = 0; i < pmd_index(va_text); i++) + pmd[i] &= ~_PAGE_PRESENT; + + /* fixup pages that are part of the kernel image */ + for (; i <= pmd_index(va_end); i++) + if (pmd[i] & _PAGE_PRESENT) + pmd[i] += load_delta; + + /* invalidate pages after the kernel image */ + for (; i < PTRS_PER_PMD; i++) + pmd[i] &= ~_PAGE_PRESENT; + + return sme_postprocess_startup(bp, pmd, p2v_offset); +} diff --git a/arch/x86/boot/startup/sev-shared.c b/arch/x86/boot/startup/sev-shared.c new file mode 100644 index 000000000..d9ac3a929 --- /dev/null +++ b/arch/x86/boot/startup/sev-shared.c @@ -0,0 +1,762 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AMD Encrypted Register State Support + * + * Author: Joerg Roedel <jroedel@suse.de> + * + * This file is not compiled stand-alone. It contains code shared + * between the pre-decompression boot code and the running Linux kernel + * and is included directly into both code-bases. + */ + +#include <asm/setup_data.h> + +#ifndef __BOOT_COMPRESSED +#define has_cpuflag(f) cpu_feature_enabled(f) +#else +#undef WARN +#define WARN(condition, format...) (!!(condition)) +#endif + +/* Copy of the SNP firmware's CPUID page. */ +static struct snp_cpuid_table cpuid_table_copy __ro_after_init; + +/* + * These will be initialized based on CPUID table so that non-present + * all-zero leaves (for sparse tables) can be differentiated from + * invalid/out-of-range leaves. This is needed since all-zero leaves + * still need to be post-processed. + */ +static u32 cpuid_std_range_max __ro_after_init; +static u32 cpuid_hyp_range_max __ro_after_init; +static u32 cpuid_ext_range_max __ro_after_init; + +bool sev_snp_needs_sfw __section(".data"); + +void __noreturn +sev_es_terminate(unsigned int set, unsigned int reason) +{ + u64 val = GHCB_MSR_TERM_REQ; + + /* Tell the hypervisor what went wrong. */ + val |= GHCB_SEV_TERM_REASON(set, reason); + + /* Request Guest Termination from Hypervisor */ + sev_es_wr_ghcb_msr(val); + VMGEXIT(); + + while (true) + asm volatile("hlt\n" : : : "memory"); +} + +/* + * The hypervisor features are available from GHCB version 2 onward. + */ +u64 __init get_hv_features(void) +{ + u64 val; + + if (ghcb_version < 2) + return 0; + + sev_es_wr_ghcb_msr(GHCB_MSR_HV_FT_REQ); + VMGEXIT(); + + val = sev_es_rd_ghcb_msr(); + if (GHCB_RESP_CODE(val) != GHCB_MSR_HV_FT_RESP) + return 0; + + return GHCB_MSR_HV_FT_RESP_VAL(val); +} + +int svsm_process_result_codes(struct svsm_call *call) +{ + switch (call->rax_out) { + case SVSM_SUCCESS: + return 0; + case SVSM_ERR_INCOMPLETE: + case SVSM_ERR_BUSY: + return -EAGAIN; + default: + return -EINVAL; + } +} + +/* + * Issue a VMGEXIT to call the SVSM: + * - Load the SVSM register state (RAX, RCX, RDX, R8 and R9) + * - Set the CA call pending field to 1 + * - Issue VMGEXIT + * - Save the SVSM return register state (RAX, RCX, RDX, R8 and R9) + * - Perform atomic exchange of the CA call pending field + * + * - See the "Secure VM Service Module for SEV-SNP Guests" specification for + * details on the calling convention. + * - The calling convention loosely follows the Microsoft X64 calling + * convention by putting arguments in RCX, RDX, R8 and R9. + * - RAX specifies the SVSM protocol/callid as input and the return code + * as output. + */ +void svsm_issue_call(struct svsm_call *call, u8 *pending) +{ + register unsigned long rax asm("rax") = call->rax; + register unsigned long rcx asm("rcx") = call->rcx; + register unsigned long rdx asm("rdx") = call->rdx; + register unsigned long r8 asm("r8") = call->r8; + register unsigned long r9 asm("r9") = call->r9; + + call->caa->call_pending = 1; + + asm volatile("rep; vmmcall\n\t" + : "+r" (rax), "+r" (rcx), "+r" (rdx), "+r" (r8), "+r" (r9) + : : "memory"); + + *pending = xchg(&call->caa->call_pending, *pending); + + call->rax_out = rax; + call->rcx_out = rcx; + call->rdx_out = rdx; + call->r8_out = r8; + call->r9_out = r9; +} + +int svsm_perform_msr_protocol(struct svsm_call *call) +{ + u8 pending = 0; + u64 val, resp; + + /* + * When using the MSR protocol, be sure to save and restore + * the current MSR value. + */ + val = sev_es_rd_ghcb_msr(); + + sev_es_wr_ghcb_msr(GHCB_MSR_VMPL_REQ_LEVEL(0)); + + svsm_issue_call(call, &pending); + + resp = sev_es_rd_ghcb_msr(); + + sev_es_wr_ghcb_msr(val); + + if (pending) + return -EINVAL; + + if (GHCB_RESP_CODE(resp) != GHCB_MSR_VMPL_RESP) + return -EINVAL; + + if (GHCB_MSR_VMPL_RESP_VAL(resp)) + return -EINVAL; + + return svsm_process_result_codes(call); +} + +static int __sev_cpuid_hv(u32 fn, int reg_idx, u32 *reg) +{ + u64 val; + + sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, reg_idx)); + VMGEXIT(); + val = sev_es_rd_ghcb_msr(); + if (GHCB_RESP_CODE(val) != GHCB_MSR_CPUID_RESP) + return -EIO; + + *reg = (val >> 32); + + return 0; +} + +static int __sev_cpuid_hv_msr(struct cpuid_leaf *leaf) +{ + int ret; + + /* + * MSR protocol does not support fetching non-zero subfunctions, but is + * sufficient to handle current early-boot cases. Should that change, + * make sure to report an error rather than ignoring the index and + * grabbing random values. If this issue arises in the future, handling + * can be added here to use GHCB-page protocol for cases that occur late + * enough in boot that GHCB page is available. + */ + if (cpuid_function_is_indexed(leaf->fn) && leaf->subfn) + return -EINVAL; + + ret = __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EAX, &leaf->eax); + ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EBX, &leaf->ebx); + ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_ECX, &leaf->ecx); + ret = ret ? : __sev_cpuid_hv(leaf->fn, GHCB_CPUID_REQ_EDX, &leaf->edx); + + return ret; +} + + + +/* + * This may be called early while still running on the initial identity + * mapping. Use RIP-relative addressing to obtain the correct address + * while running with the initial identity mapping as well as the + * switch-over to kernel virtual addresses later. + */ +const struct snp_cpuid_table *snp_cpuid_get_table(void) +{ + return rip_rel_ptr(&cpuid_table_copy); +} + +/* + * The SNP Firmware ABI, Revision 0.9, Section 7.1, details the use of + * XCR0_IN and XSS_IN to encode multiple versions of 0xD subfunctions 0 + * and 1 based on the corresponding features enabled by a particular + * combination of XCR0 and XSS registers so that a guest can look up the + * version corresponding to the features currently enabled in its XCR0/XSS + * registers. The only values that differ between these versions/table + * entries is the enabled XSAVE area size advertised via EBX. + * + * While hypervisors may choose to make use of this support, it is more + * robust/secure for a guest to simply find the entry corresponding to the + * base/legacy XSAVE area size (XCR0=1 or XCR0=3), and then calculate the + * XSAVE area size using subfunctions 2 through 64, as documented in APM + * Volume 3, Rev 3.31, Appendix E.3.8, which is what is done here. + * + * Since base/legacy XSAVE area size is documented as 0x240, use that value + * directly rather than relying on the base size in the CPUID table. + * + * Return: XSAVE area size on success, 0 otherwise. + */ +static u32 snp_cpuid_calc_xsave_size(u64 xfeatures_en, bool compacted) +{ + const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); + u64 xfeatures_found = 0; + u32 xsave_size = 0x240; + int i; + + for (i = 0; i < cpuid_table->count; i++) { + const struct snp_cpuid_fn *e = &cpuid_table->fn[i]; + + if (!(e->eax_in == 0xD && e->ecx_in > 1 && e->ecx_in < 64)) + continue; + if (!(xfeatures_en & (BIT_ULL(e->ecx_in)))) + continue; + if (xfeatures_found & (BIT_ULL(e->ecx_in))) + continue; + + xfeatures_found |= (BIT_ULL(e->ecx_in)); + + if (compacted) + xsave_size += e->eax; + else + xsave_size = max(xsave_size, e->eax + e->ebx); + } + + /* + * Either the guest set unsupported XCR0/XSS bits, or the corresponding + * entries in the CPUID table were not present. This is not a valid + * state to be in. + */ + if (xfeatures_found != (xfeatures_en & GENMASK_ULL(63, 2))) + return 0; + + return xsave_size; +} + +static bool +snp_cpuid_get_validated_func(struct cpuid_leaf *leaf) +{ + const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); + int i; + + for (i = 0; i < cpuid_table->count; i++) { + const struct snp_cpuid_fn *e = &cpuid_table->fn[i]; + + if (e->eax_in != leaf->fn) + continue; + + if (cpuid_function_is_indexed(leaf->fn) && e->ecx_in != leaf->subfn) + continue; + + /* + * For 0xD subfunctions 0 and 1, only use the entry corresponding + * to the base/legacy XSAVE area size (XCR0=1 or XCR0=3, XSS=0). + * See the comments above snp_cpuid_calc_xsave_size() for more + * details. + */ + if (e->eax_in == 0xD && (e->ecx_in == 0 || e->ecx_in == 1)) + if (!(e->xcr0_in == 1 || e->xcr0_in == 3) || e->xss_in) + continue; + + leaf->eax = e->eax; + leaf->ebx = e->ebx; + leaf->ecx = e->ecx; + leaf->edx = e->edx; + + return true; + } + + return false; +} + +static void snp_cpuid_hv_msr(void *ctx, struct cpuid_leaf *leaf) +{ + if (__sev_cpuid_hv_msr(leaf)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID_HV); +} + +static int +snp_cpuid_postprocess(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf), + void *ctx, struct cpuid_leaf *leaf) +{ + struct cpuid_leaf leaf_hv = *leaf; + + switch (leaf->fn) { + case 0x1: + cpuid_fn(ctx, &leaf_hv); + + /* initial APIC ID */ + leaf->ebx = (leaf_hv.ebx & GENMASK(31, 24)) | (leaf->ebx & GENMASK(23, 0)); + /* APIC enabled bit */ + leaf->edx = (leaf_hv.edx & BIT(9)) | (leaf->edx & ~BIT(9)); + + /* OSXSAVE enabled bit */ + if (native_read_cr4() & X86_CR4_OSXSAVE) + leaf->ecx |= BIT(27); + break; + case 0x7: + /* OSPKE enabled bit */ + leaf->ecx &= ~BIT(4); + if (native_read_cr4() & X86_CR4_PKE) + leaf->ecx |= BIT(4); + break; + case 0xB: + leaf_hv.subfn = 0; + cpuid_fn(ctx, &leaf_hv); + + /* extended APIC ID */ + leaf->edx = leaf_hv.edx; + break; + case 0xD: { + bool compacted = false; + u64 xcr0 = 1, xss = 0; + u32 xsave_size; + + if (leaf->subfn != 0 && leaf->subfn != 1) + return 0; + + if (native_read_cr4() & X86_CR4_OSXSAVE) + xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK); + if (leaf->subfn == 1) { + /* Get XSS value if XSAVES is enabled. */ + if (leaf->eax & BIT(3)) { + unsigned long lo, hi; + + asm volatile("rdmsr" : "=a" (lo), "=d" (hi) + : "c" (MSR_IA32_XSS)); + xss = (hi << 32) | lo; + } + + /* + * The PPR and APM aren't clear on what size should be + * encoded in 0xD:0x1:EBX when compaction is not enabled + * by either XSAVEC (feature bit 1) or XSAVES (feature + * bit 3) since SNP-capable hardware has these feature + * bits fixed as 1. KVM sets it to 0 in this case, but + * to avoid this becoming an issue it's safer to simply + * treat this as unsupported for SNP guests. + */ + if (!(leaf->eax & (BIT(1) | BIT(3)))) + return -EINVAL; + + compacted = true; + } + + xsave_size = snp_cpuid_calc_xsave_size(xcr0 | xss, compacted); + if (!xsave_size) + return -EINVAL; + + leaf->ebx = xsave_size; + } + break; + case 0x8000001E: + cpuid_fn(ctx, &leaf_hv); + + /* extended APIC ID */ + leaf->eax = leaf_hv.eax; + /* compute ID */ + leaf->ebx = (leaf->ebx & GENMASK(31, 8)) | (leaf_hv.ebx & GENMASK(7, 0)); + /* node ID */ + leaf->ecx = (leaf->ecx & GENMASK(31, 8)) | (leaf_hv.ecx & GENMASK(7, 0)); + break; + default: + /* No fix-ups needed, use values as-is. */ + break; + } + + return 0; +} + +/* + * Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value + * should be treated as fatal by caller. + */ +int snp_cpuid(void (*cpuid_fn)(void *ctx, struct cpuid_leaf *leaf), + void *ctx, struct cpuid_leaf *leaf) +{ + const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table(); + + if (!cpuid_table->count) + return -EOPNOTSUPP; + + if (!snp_cpuid_get_validated_func(leaf)) { + /* + * Some hypervisors will avoid keeping track of CPUID entries + * where all values are zero, since they can be handled the + * same as out-of-range values (all-zero). This is useful here + * as well as it allows virtually all guest configurations to + * work using a single SNP CPUID table. + * + * To allow for this, there is a need to distinguish between + * out-of-range entries and in-range zero entries, since the + * CPUID table entries are only a template that may need to be + * augmented with additional values for things like + * CPU-specific information during post-processing. So if it's + * not in the table, set the values to zero. Then, if they are + * within a valid CPUID range, proceed with post-processing + * using zeros as the initial values. Otherwise, skip + * post-processing and just return zeros immediately. + */ + leaf->eax = leaf->ebx = leaf->ecx = leaf->edx = 0; + + /* Skip post-processing for out-of-range zero leafs. */ + if (!(leaf->fn <= cpuid_std_range_max || + (leaf->fn >= 0x40000000 && leaf->fn <= cpuid_hyp_range_max) || + (leaf->fn >= 0x80000000 && leaf->fn <= cpuid_ext_range_max))) + return 0; + } + + return snp_cpuid_postprocess(cpuid_fn, ctx, leaf); +} + +/* + * Boot VC Handler - This is the first VC handler during boot, there is no GHCB + * page yet, so it only supports the MSR based communication with the + * hypervisor and only the CPUID exit-code. + */ +void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code) +{ + unsigned int subfn = lower_bits(regs->cx, 32); + unsigned int fn = lower_bits(regs->ax, 32); + u16 opcode = *(unsigned short *)regs->ip; + struct cpuid_leaf leaf; + int ret; + + /* Only CPUID is supported via MSR protocol */ + if (exit_code != SVM_EXIT_CPUID) + goto fail; + + /* Is it really a CPUID insn? */ + if (opcode != 0xa20f) + goto fail; + + leaf.fn = fn; + leaf.subfn = subfn; + + /* + * If SNP is active, then snp_cpuid() uses the CPUID table to obtain the + * CPUID values (with possible HV interaction during post-processing of + * the values). But if SNP is not active (no CPUID table present), then + * snp_cpuid() returns -EOPNOTSUPP so that an SEV-ES guest can call the + * HV to obtain the CPUID information. + */ + ret = snp_cpuid(snp_cpuid_hv_msr, NULL, &leaf); + if (!ret) + goto cpuid_done; + + if (ret != -EOPNOTSUPP) + goto fail; + + /* + * This is reached by a SEV-ES guest and needs to invoke the HV for + * the CPUID data. + */ + if (__sev_cpuid_hv_msr(&leaf)) + goto fail; + +cpuid_done: + regs->ax = leaf.eax; + regs->bx = leaf.ebx; + regs->cx = leaf.ecx; + regs->dx = leaf.edx; + + /* + * This is a VC handler and the #VC is only raised when SEV-ES is + * active, which means SEV must be active too. Do sanity checks on the + * CPUID results to make sure the hypervisor does not trick the kernel + * into the no-sev path. This could map sensitive data unencrypted and + * make it accessible to the hypervisor. + * + * In particular, check for: + * - Availability of CPUID leaf 0x8000001f + * - SEV CPUID bit. + * + * The hypervisor might still report the wrong C-bit position, but this + * can't be checked here. + */ + + if (fn == 0x80000000 && (regs->ax < 0x8000001f)) + /* SEV leaf check */ + goto fail; + else if ((fn == 0x8000001f && !(regs->ax & BIT(1)))) + /* SEV bit */ + goto fail; + + /* Skip over the CPUID two-byte opcode */ + regs->ip += 2; + + return; + +fail: + /* Terminate the guest */ + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ); +} + +struct cc_setup_data { + struct setup_data header; + u32 cc_blob_address; +}; + +/* + * Search for a Confidential Computing blob passed in as a setup_data entry + * via the Linux Boot Protocol. + */ +static __init +struct cc_blob_sev_info *find_cc_blob_setup_data(struct boot_params *bp) +{ + struct cc_setup_data *sd = NULL; + struct setup_data *hdr; + + hdr = (struct setup_data *)bp->hdr.setup_data; + + while (hdr) { + if (hdr->type == SETUP_CC_BLOB) { + sd = (struct cc_setup_data *)hdr; + return (struct cc_blob_sev_info *)(unsigned long)sd->cc_blob_address; + } + hdr = (struct setup_data *)hdr->next; + } + + return NULL; +} + +/* + * Initialize the kernel's copy of the SNP CPUID table, and set up the + * pointer that will be used to access it. + * + * Maintaining a direct mapping of the SNP CPUID table used by firmware would + * be possible as an alternative, but the approach is brittle since the + * mapping needs to be updated in sync with all the changes to virtual memory + * layout and related mapping facilities throughout the boot process. + */ +static void __init setup_cpuid_table(const struct cc_blob_sev_info *cc_info) +{ + const struct snp_cpuid_table *cpuid_table_fw, *cpuid_table; + int i; + + if (!cc_info || !cc_info->cpuid_phys || cc_info->cpuid_len < PAGE_SIZE) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID); + + cpuid_table_fw = (const struct snp_cpuid_table *)cc_info->cpuid_phys; + if (!cpuid_table_fw->count || cpuid_table_fw->count > SNP_CPUID_COUNT_MAX) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_CPUID); + + cpuid_table = snp_cpuid_get_table(); + memcpy((void *)cpuid_table, cpuid_table_fw, sizeof(*cpuid_table)); + + /* Initialize CPUID ranges for range-checking. */ + for (i = 0; i < cpuid_table->count; i++) { + const struct snp_cpuid_fn *fn = &cpuid_table->fn[i]; + + if (fn->eax_in == 0x0) + cpuid_std_range_max = fn->eax; + else if (fn->eax_in == 0x40000000) + cpuid_hyp_range_max = fn->eax; + else if (fn->eax_in == 0x80000000) + cpuid_ext_range_max = fn->eax; + } +} + +static int svsm_call_msr_protocol(struct svsm_call *call) +{ + int ret; + + do { + ret = svsm_perform_msr_protocol(call); + } while (ret == -EAGAIN); + + return ret; +} + +static void svsm_pval_4k_page(unsigned long paddr, bool validate, + struct svsm_ca *caa, u64 caa_pa) +{ + struct svsm_pvalidate_call *pc; + struct svsm_call call = {}; + unsigned long flags; + u64 pc_pa; + + /* + * This can be called very early in the boot, use native functions in + * order to avoid paravirt issues. + */ + flags = native_local_irq_save(); + + call.caa = caa; + + pc = (struct svsm_pvalidate_call *)call.caa->svsm_buffer; + pc_pa = caa_pa + offsetof(struct svsm_ca, svsm_buffer); + + pc->num_entries = 1; + pc->cur_index = 0; + pc->entry[0].page_size = RMP_PG_SIZE_4K; + pc->entry[0].action = validate; + pc->entry[0].ignore_cf = 0; + pc->entry[0].rsvd = 0; + pc->entry[0].pfn = paddr >> PAGE_SHIFT; + + /* Protocol 0, Call ID 1 */ + call.rax = SVSM_CORE_CALL(SVSM_CORE_PVALIDATE); + call.rcx = pc_pa; + + /* + * Use the MSR protocol exclusively, so that this code is usable in + * startup code where VA/PA translations of the GHCB page's address may + * be problematic. + */ + if (svsm_call_msr_protocol(&call)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE); + + native_local_irq_restore(flags); +} + +static void pvalidate_4k_page(unsigned long vaddr, unsigned long paddr, + bool validate, struct svsm_ca *caa, u64 caa_pa) +{ + int ret; + + if (snp_vmpl) { + svsm_pval_4k_page(paddr, validate, caa, caa_pa); + } else { + ret = pvalidate(vaddr, RMP_PG_SIZE_4K, validate); + if (ret) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PVALIDATE); + } + + /* + * If validating memory (making it private) and affected by the + * cache-coherency vulnerability, perform the cache eviction mitigation. + */ + if (validate && sev_snp_needs_sfw) + sev_evict_cache((void *)vaddr, 1); +} + +static void __page_state_change(unsigned long vaddr, unsigned long paddr, + const struct psc_desc *desc) +{ + u64 val, msr; + + /* + * If private -> shared then invalidate the page before requesting the + * state change in the RMP table. + */ + if (desc->op == SNP_PAGE_STATE_SHARED) + pvalidate_4k_page(vaddr, paddr, false, desc->ca, desc->caa_pa); + + /* Save the current GHCB MSR value */ + msr = sev_es_rd_ghcb_msr(); + + /* Issue VMGEXIT to change the page state in RMP table. */ + sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, desc->op)); + VMGEXIT(); + + /* Read the response of the VMGEXIT. */ + val = sev_es_rd_ghcb_msr(); + if ((GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) || GHCB_MSR_PSC_RESP_VAL(val)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); + + /* Restore the GHCB MSR value */ + sev_es_wr_ghcb_msr(msr); + + /* + * Now that page state is changed in the RMP table, validate it so that it is + * consistent with the RMP entry. + */ + if (desc->op == SNP_PAGE_STATE_PRIVATE) + pvalidate_4k_page(vaddr, paddr, true, desc->ca, desc->caa_pa); +} + +/* + * Maintain the GPA of the SVSM Calling Area (CA) in order to utilize the SVSM + * services needed when not running in VMPL0. + */ +static bool __init svsm_setup_ca(const struct cc_blob_sev_info *cc_info, + void *page) +{ + struct snp_secrets_page *secrets_page; + struct snp_cpuid_table *cpuid_table; + unsigned int i; + u64 caa; + + BUILD_BUG_ON(sizeof(*secrets_page) != PAGE_SIZE); + + /* + * Check if running at VMPL0. + * + * Use RMPADJUST (see the rmpadjust() function for a description of what + * the instruction does) to update the VMPL1 permissions of a page. If + * the guest is running at VMPL0, this will succeed and implies there is + * no SVSM. If the guest is running at any other VMPL, this will fail. + * Linux SNP guests only ever run at a single VMPL level so permission mask + * changes of a lesser-privileged VMPL are a don't-care. + * + * Use a rip-relative reference to obtain the proper address, since this + * routine is running identity mapped when called, both by the decompressor + * code and the early kernel code. + */ + if (!rmpadjust((unsigned long)page, RMP_PG_SIZE_4K, 1)) + return false; + + /* + * Not running at VMPL0, ensure everything has been properly supplied + * for running under an SVSM. + */ + if (!cc_info || !cc_info->secrets_phys || cc_info->secrets_len != PAGE_SIZE) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SECRETS_PAGE); + + secrets_page = (struct snp_secrets_page *)cc_info->secrets_phys; + if (!secrets_page->svsm_size) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_NO_SVSM); + + if (!secrets_page->svsm_guest_vmpl) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_VMPL0); + + snp_vmpl = secrets_page->svsm_guest_vmpl; + + caa = secrets_page->svsm_caa; + + /* + * An open-coded PAGE_ALIGNED() in order to avoid including + * kernel-proper headers into the decompressor. + */ + if (caa & (PAGE_SIZE - 1)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CAA); + + boot_svsm_caa_pa = caa; + + /* Advertise the SVSM presence via CPUID. */ + cpuid_table = (struct snp_cpuid_table *)snp_cpuid_get_table(); + for (i = 0; i < cpuid_table->count; i++) { + struct snp_cpuid_fn *fn = &cpuid_table->fn[i]; + + if (fn->eax_in == 0x8000001f) + fn->eax |= BIT(28); + } + + return true; +} diff --git a/arch/x86/boot/startup/sev-startup.c b/arch/x86/boot/startup/sev-startup.c new file mode 100644 index 000000000..789e99d38 --- /dev/null +++ b/arch/x86/boot/startup/sev-startup.c @@ -0,0 +1,221 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2019 SUSE + * + * Author: Joerg Roedel <jroedel@suse.de> + */ + +#define pr_fmt(fmt) "SEV: " fmt + +#include <linux/percpu-defs.h> +#include <linux/cc_platform.h> +#include <linux/printk.h> +#include <linux/mm_types.h> +#include <linux/set_memory.h> +#include <linux/memblock.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/cpumask.h> +#include <linux/efi.h> +#include <linux/io.h> +#include <linux/psp-sev.h> +#include <uapi/linux/sev-guest.h> + +#include <asm/init.h> +#include <asm/cpu_entry_area.h> +#include <asm/stacktrace.h> +#include <asm/sev.h> +#include <asm/insn-eval.h> +#include <asm/fpu/xcr.h> +#include <asm/processor.h> +#include <asm/realmode.h> +#include <asm/setup.h> +#include <asm/traps.h> +#include <asm/svm.h> +#include <asm/smp.h> +#include <asm/cpu.h> +#include <asm/apic.h> +#include <asm/cpuid/api.h> +#include <asm/cmdline.h> + +#include "../../coco/sev/internal.h" + +/* Include code shared with pre-decompression boot stage */ +#include "sev-shared.c" + +void +early_set_pages_state(unsigned long vaddr, unsigned long paddr, + unsigned long npages, const struct psc_desc *desc) +{ + unsigned long paddr_end; + + vaddr = vaddr & PAGE_MASK; + + paddr = paddr & PAGE_MASK; + paddr_end = paddr + (npages << PAGE_SHIFT); + + while (paddr < paddr_end) { + __page_state_change(vaddr, paddr, desc); + + vaddr += PAGE_SIZE; + paddr += PAGE_SIZE; + } +} + +void __init early_snp_set_memory_private(unsigned long vaddr, unsigned long paddr, + unsigned long npages) +{ + struct psc_desc d = { + SNP_PAGE_STATE_PRIVATE, + rip_rel_ptr(&boot_svsm_ca_page), + boot_svsm_caa_pa + }; + + /* + * This can be invoked in early boot while running identity mapped, so + * use an open coded check for SNP instead of using cc_platform_has(). + * This eliminates worries about jump tables or checking boot_cpu_data + * in the cc_platform_has() function. + */ + if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) + return; + + /* + * Ask the hypervisor to mark the memory pages as private in the RMP + * table. + */ + early_set_pages_state(vaddr, paddr, npages, &d); +} + +void __init early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr, + unsigned long npages) +{ + struct psc_desc d = { + SNP_PAGE_STATE_SHARED, + rip_rel_ptr(&boot_svsm_ca_page), + boot_svsm_caa_pa + }; + + /* + * This can be invoked in early boot while running identity mapped, so + * use an open coded check for SNP instead of using cc_platform_has(). + * This eliminates worries about jump tables or checking boot_cpu_data + * in the cc_platform_has() function. + */ + if (!(sev_status & MSR_AMD64_SEV_SNP_ENABLED)) + return; + + /* Ask hypervisor to mark the memory pages shared in the RMP table. */ + early_set_pages_state(vaddr, paddr, npages, &d); +} + +/* + * Initial set up of SNP relies on information provided by the + * Confidential Computing blob, which can be passed to the kernel + * in the following ways, depending on how it is booted: + * + * - when booted via the boot/decompress kernel: + * - via boot_params + * + * - when booted directly by firmware/bootloader (e.g. CONFIG_PVH): + * - via a setup_data entry, as defined by the Linux Boot Protocol + * + * Scan for the blob in that order. + */ +static struct cc_blob_sev_info *__init find_cc_blob(struct boot_params *bp) +{ + struct cc_blob_sev_info *cc_info; + + /* Boot kernel would have passed the CC blob via boot_params. */ + if (bp->cc_blob_address) { + cc_info = (struct cc_blob_sev_info *)(unsigned long)bp->cc_blob_address; + goto found_cc_info; + } + + /* + * If kernel was booted directly, without the use of the + * boot/decompression kernel, the CC blob may have been passed via + * setup_data instead. + */ + cc_info = find_cc_blob_setup_data(bp); + if (!cc_info) + return NULL; + +found_cc_info: + if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + + return cc_info; +} + +static void __init svsm_setup(struct cc_blob_sev_info *cc_info) +{ + struct snp_secrets_page *secrets = (void *)cc_info->secrets_phys; + struct svsm_call call = {}; + u64 pa; + + /* + * Record the SVSM Calling Area address (CAA) if the guest is not + * running at VMPL0. The CA will be used to communicate with the + * SVSM to perform the SVSM services. + */ + if (!svsm_setup_ca(cc_info, rip_rel_ptr(&boot_svsm_ca_page))) + return; + + /* + * It is very early in the boot and the kernel is running identity + * mapped but without having adjusted the pagetables to where the + * kernel was loaded (physbase), so the get the CA address using + * RIP-relative addressing. + */ + pa = (u64)rip_rel_ptr(&boot_svsm_ca_page); + + /* + * Switch over to the boot SVSM CA while the current CA is still 1:1 + * mapped and thus addressable with VA == PA. There is no GHCB at this + * point so use the MSR protocol. + * + * SVSM_CORE_REMAP_CA call: + * RAX = 0 (Protocol=0, CallID=0) + * RCX = New CA GPA + */ + call.caa = (struct svsm_ca *)secrets->svsm_caa; + call.rax = SVSM_CORE_CALL(SVSM_CORE_REMAP_CA); + call.rcx = pa; + + if (svsm_call_msr_protocol(&call)) + sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_SVSM_CA_REMAP_FAIL); + + boot_svsm_caa_pa = pa; +} + +bool __init snp_init(struct boot_params *bp) +{ + struct cc_blob_sev_info *cc_info; + + if (!bp) + return false; + + cc_info = find_cc_blob(bp); + if (!cc_info) + return false; + + if (cc_info->secrets_phys && cc_info->secrets_len == PAGE_SIZE) + sev_secrets_pa = cc_info->secrets_phys; + else + return false; + + setup_cpuid_table(cc_info); + + svsm_setup(cc_info); + + /* + * The CC blob will be used later to access the secrets page. Cache + * it here like the boot kernel does. + */ + bp->cc_blob_address = (u32)(unsigned long)cc_info; + + return true; +} diff --git a/arch/x86/boot/startup/sme.c b/arch/x86/boot/startup/sme.c new file mode 100644 index 000000000..c07a2c381 --- /dev/null +++ b/arch/x86/boot/startup/sme.c @@ -0,0 +1,577 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD Memory Encryption Support + * + * Copyright (C) 2016 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky <thomas.lendacky@amd.com> + */ + +/* + * Since we're dealing with identity mappings, physical and virtual + * addresses are the same, so override these defines which are ultimately + * used by the headers in misc.h. + */ +#define __pa(x) ((unsigned long)(x)) +#define __va(x) ((void *)((unsigned long)(x))) + +/* + * Special hack: we have to be careful, because no indirections are + * allowed here, and paravirt_ops is a kind of one. As it will only run in + * baremetal anyway, we just keep it from happening. (This list needs to + * be extended when new paravirt and debugging variants are added.) + */ +#undef CONFIG_PARAVIRT +#undef CONFIG_PARAVIRT_XXL +#undef CONFIG_PARAVIRT_SPINLOCKS +#undef CONFIG_ARCH_HAS_LAZY_MMU_MODE + +/* + * This code runs before CPU feature bits are set. By default, the + * pgtable_l5_enabled() function uses bit X86_FEATURE_LA57 to determine if + * 5-level paging is active, so that won't work here. USE_EARLY_PGTABLE_L5 + * is provided to handle this situation and, instead, use a variable that + * has been set by the early boot code. + */ +#define USE_EARLY_PGTABLE_L5 + +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/mem_encrypt.h> +#include <linux/cc_platform.h> + +#include <asm/init.h> +#include <asm/setup.h> +#include <asm/sections.h> +#include <asm/cpuid/api.h> +#include <asm/coco.h> +#include <asm/sev.h> + +#define PGD_FLAGS _KERNPG_TABLE_NOENC +#define P4D_FLAGS _KERNPG_TABLE_NOENC +#define PUD_FLAGS _KERNPG_TABLE_NOENC +#define PMD_FLAGS _KERNPG_TABLE_NOENC + +#define PMD_FLAGS_LARGE (__PAGE_KERNEL_LARGE_EXEC & ~_PAGE_GLOBAL) + +#define PMD_FLAGS_DEC PMD_FLAGS_LARGE +#define PMD_FLAGS_DEC_WP ((PMD_FLAGS_DEC & ~_PAGE_LARGE_CACHE_MASK) | \ + (_PAGE_PAT_LARGE | _PAGE_PWT)) + +#define PMD_FLAGS_ENC (PMD_FLAGS_LARGE | _PAGE_ENC) + +#define PTE_FLAGS (__PAGE_KERNEL_EXEC & ~_PAGE_GLOBAL) + +#define PTE_FLAGS_DEC PTE_FLAGS +#define PTE_FLAGS_DEC_WP ((PTE_FLAGS_DEC & ~_PAGE_CACHE_MASK) | \ + (_PAGE_PAT | _PAGE_PWT)) + +#define PTE_FLAGS_ENC (PTE_FLAGS | _PAGE_ENC) + +struct sme_populate_pgd_data { + void *pgtable_area; + pgd_t *pgd; + + pmdval_t pmd_flags; + pteval_t pte_flags; + unsigned long paddr; + + unsigned long vaddr; + unsigned long vaddr_end; +}; + +/* + * This work area lives in the .init.scratch section, which lives outside of + * the kernel proper. It is sized to hold the intermediate copy buffer and + * more than enough pagetable pages. + * + * By using this section, the kernel can be encrypted in place and it + * avoids any possibility of boot parameters or initramfs images being + * placed such that the in-place encryption logic overwrites them. This + * section is 2MB aligned to allow for simple pagetable setup using only + * PMD entries (see vmlinux.lds.S). + */ +static char sme_workarea[2 * PMD_SIZE] __section(".init.scratch"); + +static void __init sme_clear_pgd(struct sme_populate_pgd_data *ppd) +{ + unsigned long pgd_start, pgd_end, pgd_size; + pgd_t *pgd_p; + + pgd_start = ppd->vaddr & PGDIR_MASK; + pgd_end = ppd->vaddr_end & PGDIR_MASK; + + pgd_size = (((pgd_end - pgd_start) / PGDIR_SIZE) + 1) * sizeof(pgd_t); + + pgd_p = ppd->pgd + pgd_index(ppd->vaddr); + + memset(pgd_p, 0, pgd_size); +} + +static pud_t __init *sme_prepare_pgd(struct sme_populate_pgd_data *ppd) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + + pgd = ppd->pgd + pgd_index(ppd->vaddr); + if (pgd_none(*pgd)) { + p4d = ppd->pgtable_area; + memset(p4d, 0, sizeof(*p4d) * PTRS_PER_P4D); + ppd->pgtable_area += sizeof(*p4d) * PTRS_PER_P4D; + set_pgd(pgd, __pgd(PGD_FLAGS | __pa(p4d))); + } + + p4d = p4d_offset(pgd, ppd->vaddr); + if (p4d_none(*p4d)) { + pud = ppd->pgtable_area; + memset(pud, 0, sizeof(*pud) * PTRS_PER_PUD); + ppd->pgtable_area += sizeof(*pud) * PTRS_PER_PUD; + set_p4d(p4d, __p4d(P4D_FLAGS | __pa(pud))); + } + + pud = pud_offset(p4d, ppd->vaddr); + if (pud_none(*pud)) { + pmd = ppd->pgtable_area; + memset(pmd, 0, sizeof(*pmd) * PTRS_PER_PMD); + ppd->pgtable_area += sizeof(*pmd) * PTRS_PER_PMD; + set_pud(pud, __pud(PUD_FLAGS | __pa(pmd))); + } + + if (pud_leaf(*pud)) + return NULL; + + return pud; +} + +static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd) +{ + pud_t *pud; + pmd_t *pmd; + + pud = sme_prepare_pgd(ppd); + if (!pud) + return; + + pmd = pmd_offset(pud, ppd->vaddr); + if (pmd_leaf(*pmd)) + return; + + set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags)); +} + +static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd) +{ + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + + pud = sme_prepare_pgd(ppd); + if (!pud) + return; + + pmd = pmd_offset(pud, ppd->vaddr); + if (pmd_none(*pmd)) { + pte = ppd->pgtable_area; + memset(pte, 0, sizeof(*pte) * PTRS_PER_PTE); + ppd->pgtable_area += sizeof(*pte) * PTRS_PER_PTE; + set_pmd(pmd, __pmd(PMD_FLAGS | __pa(pte))); + } + + if (pmd_leaf(*pmd)) + return; + + pte = pte_offset_kernel(pmd, ppd->vaddr); + if (pte_none(*pte)) + set_pte(pte, __pte(ppd->paddr | ppd->pte_flags)); +} + +static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd) +{ + while (ppd->vaddr < ppd->vaddr_end) { + sme_populate_pgd_large(ppd); + + ppd->vaddr += PMD_SIZE; + ppd->paddr += PMD_SIZE; + } +} + +static void __init __sme_map_range_pte(struct sme_populate_pgd_data *ppd) +{ + while (ppd->vaddr < ppd->vaddr_end) { + sme_populate_pgd(ppd); + + ppd->vaddr += PAGE_SIZE; + ppd->paddr += PAGE_SIZE; + } +} + +static void __init __sme_map_range(struct sme_populate_pgd_data *ppd, + pmdval_t pmd_flags, pteval_t pte_flags) +{ + unsigned long vaddr_end; + + ppd->pmd_flags = pmd_flags; + ppd->pte_flags = pte_flags; + + /* Save original end value since we modify the struct value */ + vaddr_end = ppd->vaddr_end; + + /* If start is not 2MB aligned, create PTE entries */ + ppd->vaddr_end = ALIGN(ppd->vaddr, PMD_SIZE); + __sme_map_range_pte(ppd); + + /* Create PMD entries */ + ppd->vaddr_end = vaddr_end & PMD_MASK; + __sme_map_range_pmd(ppd); + + /* If end is not 2MB aligned, create PTE entries */ + ppd->vaddr_end = vaddr_end; + __sme_map_range_pte(ppd); +} + +static void __init sme_map_range_encrypted(struct sme_populate_pgd_data *ppd) +{ + __sme_map_range(ppd, PMD_FLAGS_ENC, PTE_FLAGS_ENC); +} + +static void __init sme_map_range_decrypted(struct sme_populate_pgd_data *ppd) +{ + __sme_map_range(ppd, PMD_FLAGS_DEC, PTE_FLAGS_DEC); +} + +static void __init sme_map_range_decrypted_wp(struct sme_populate_pgd_data *ppd) +{ + __sme_map_range(ppd, PMD_FLAGS_DEC_WP, PTE_FLAGS_DEC_WP); +} + +static unsigned long __init sme_pgtable_calc(unsigned long len) +{ + unsigned long entries = 0, tables = 0; + + /* + * Perform a relatively simplistic calculation of the pagetable + * entries that are needed. Those mappings will be covered mostly + * by 2MB PMD entries so we can conservatively calculate the required + * number of P4D, PUD and PMD structures needed to perform the + * mappings. For mappings that are not 2MB aligned, PTE mappings + * would be needed for the start and end portion of the address range + * that fall outside of the 2MB alignment. This results in, at most, + * two extra pages to hold PTE entries for each range that is mapped. + * Incrementing the count for each covers the case where the addresses + * cross entries. + */ + + /* PGDIR_SIZE is equal to P4D_SIZE on 4-level machine. */ + if (PTRS_PER_P4D > 1) + entries += (DIV_ROUND_UP(len, PGDIR_SIZE) + 1) * sizeof(p4d_t) * PTRS_PER_P4D; + entries += (DIV_ROUND_UP(len, P4D_SIZE) + 1) * sizeof(pud_t) * PTRS_PER_PUD; + entries += (DIV_ROUND_UP(len, PUD_SIZE) + 1) * sizeof(pmd_t) * PTRS_PER_PMD; + entries += 2 * sizeof(pte_t) * PTRS_PER_PTE; + + /* + * Now calculate the added pagetable structures needed to populate + * the new pagetables. + */ + + if (PTRS_PER_P4D > 1) + tables += DIV_ROUND_UP(entries, PGDIR_SIZE) * sizeof(p4d_t) * PTRS_PER_P4D; + tables += DIV_ROUND_UP(entries, P4D_SIZE) * sizeof(pud_t) * PTRS_PER_PUD; + tables += DIV_ROUND_UP(entries, PUD_SIZE) * sizeof(pmd_t) * PTRS_PER_PMD; + + return entries + tables; +} + +void __init sme_encrypt_kernel(struct boot_params *bp) +{ + unsigned long workarea_start, workarea_end, workarea_len; + unsigned long execute_start, execute_end, execute_len; + unsigned long kernel_start, kernel_end, kernel_len; + unsigned long initrd_start, initrd_end, initrd_len; + struct sme_populate_pgd_data ppd; + unsigned long pgtable_area_len; + unsigned long decrypted_base; + + /* + * This is early code, use an open coded check for SME instead of + * using cc_platform_has(). This eliminates worries about removing + * instrumentation or checking boot_cpu_data in the cc_platform_has() + * function. + */ + if (!sme_get_me_mask() || sev_status & MSR_AMD64_SEV_ENABLED) + return; + + /* + * Prepare for encrypting the kernel and initrd by building new + * pagetables with the necessary attributes needed to encrypt the + * kernel in place. + * + * One range of virtual addresses will map the memory occupied + * by the kernel and initrd as encrypted. + * + * Another range of virtual addresses will map the memory occupied + * by the kernel and initrd as decrypted and write-protected. + * + * The use of write-protect attribute will prevent any of the + * memory from being cached. + */ + + kernel_start = (unsigned long)rip_rel_ptr(_text); + kernel_end = ALIGN((unsigned long)rip_rel_ptr(_end), PMD_SIZE); + kernel_len = kernel_end - kernel_start; + + initrd_start = 0; + initrd_end = 0; + initrd_len = 0; +#ifdef CONFIG_BLK_DEV_INITRD + initrd_len = (unsigned long)bp->hdr.ramdisk_size | + ((unsigned long)bp->ext_ramdisk_size << 32); + if (initrd_len) { + initrd_start = (unsigned long)bp->hdr.ramdisk_image | + ((unsigned long)bp->ext_ramdisk_image << 32); + initrd_end = PAGE_ALIGN(initrd_start + initrd_len); + initrd_len = initrd_end - initrd_start; + } +#endif + + /* + * Calculate required number of workarea bytes needed: + * executable encryption area size: + * stack page (PAGE_SIZE) + * encryption routine page (PAGE_SIZE) + * intermediate copy buffer (PMD_SIZE) + * pagetable structures for the encryption of the kernel + * pagetable structures for workarea (in case not currently mapped) + */ + execute_start = workarea_start = (unsigned long)rip_rel_ptr(sme_workarea); + execute_end = execute_start + (PAGE_SIZE * 2) + PMD_SIZE; + execute_len = execute_end - execute_start; + + /* + * One PGD for both encrypted and decrypted mappings and a set of + * PUDs and PMDs for each of the encrypted and decrypted mappings. + */ + pgtable_area_len = sizeof(pgd_t) * PTRS_PER_PGD; + pgtable_area_len += sme_pgtable_calc(execute_end - kernel_start) * 2; + if (initrd_len) + pgtable_area_len += sme_pgtable_calc(initrd_len) * 2; + + /* PUDs and PMDs needed in the current pagetables for the workarea */ + pgtable_area_len += sme_pgtable_calc(execute_len + pgtable_area_len); + + /* + * The total workarea includes the executable encryption area and + * the pagetable area. The start of the workarea is already 2MB + * aligned, align the end of the workarea on a 2MB boundary so that + * we don't try to create/allocate PTE entries from the workarea + * before it is mapped. + */ + workarea_len = execute_len + pgtable_area_len; + workarea_end = ALIGN(workarea_start + workarea_len, PMD_SIZE); + + /* + * Set the address to the start of where newly created pagetable + * structures (PGDs, PUDs and PMDs) will be allocated. New pagetable + * structures are created when the workarea is added to the current + * pagetables and when the new encrypted and decrypted kernel + * mappings are populated. + */ + ppd.pgtable_area = (void *)execute_end; + + /* + * Make sure the current pagetable structure has entries for + * addressing the workarea. + */ + ppd.pgd = (pgd_t *)native_read_cr3_pa(); + ppd.paddr = workarea_start; + ppd.vaddr = workarea_start; + ppd.vaddr_end = workarea_end; + sme_map_range_decrypted(&ppd); + + /* Flush the TLB - no globals so cr3 is enough */ + native_write_cr3(__native_read_cr3()); + + /* + * A new pagetable structure is being built to allow for the kernel + * and initrd to be encrypted. It starts with an empty PGD that will + * then be populated with new PUDs and PMDs as the encrypted and + * decrypted kernel mappings are created. + */ + ppd.pgd = ppd.pgtable_area; + memset(ppd.pgd, 0, sizeof(pgd_t) * PTRS_PER_PGD); + ppd.pgtable_area += sizeof(pgd_t) * PTRS_PER_PGD; + + /* + * A different PGD index/entry must be used to get different + * pagetable entries for the decrypted mapping. Choose the next + * PGD index and convert it to a virtual address to be used as + * the base of the mapping. + */ + decrypted_base = (pgd_index(workarea_end) + 1) & (PTRS_PER_PGD - 1); + if (initrd_len) { + unsigned long check_base; + + check_base = (pgd_index(initrd_end) + 1) & (PTRS_PER_PGD - 1); + decrypted_base = max(decrypted_base, check_base); + } + decrypted_base <<= PGDIR_SHIFT; + + /* Add encrypted kernel (identity) mappings */ + ppd.paddr = kernel_start; + ppd.vaddr = kernel_start; + ppd.vaddr_end = kernel_end; + sme_map_range_encrypted(&ppd); + + /* Add decrypted, write-protected kernel (non-identity) mappings */ + ppd.paddr = kernel_start; + ppd.vaddr = kernel_start + decrypted_base; + ppd.vaddr_end = kernel_end + decrypted_base; + sme_map_range_decrypted_wp(&ppd); + + if (initrd_len) { + /* Add encrypted initrd (identity) mappings */ + ppd.paddr = initrd_start; + ppd.vaddr = initrd_start; + ppd.vaddr_end = initrd_end; + sme_map_range_encrypted(&ppd); + /* + * Add decrypted, write-protected initrd (non-identity) mappings + */ + ppd.paddr = initrd_start; + ppd.vaddr = initrd_start + decrypted_base; + ppd.vaddr_end = initrd_end + decrypted_base; + sme_map_range_decrypted_wp(&ppd); + } + + /* Add decrypted workarea mappings to both kernel mappings */ + ppd.paddr = workarea_start; + ppd.vaddr = workarea_start; + ppd.vaddr_end = workarea_end; + sme_map_range_decrypted(&ppd); + + ppd.paddr = workarea_start; + ppd.vaddr = workarea_start + decrypted_base; + ppd.vaddr_end = workarea_end + decrypted_base; + sme_map_range_decrypted(&ppd); + + /* Perform the encryption */ + sme_encrypt_execute(kernel_start, kernel_start + decrypted_base, + kernel_len, workarea_start, (unsigned long)ppd.pgd); + + if (initrd_len) + sme_encrypt_execute(initrd_start, initrd_start + decrypted_base, + initrd_len, workarea_start, + (unsigned long)ppd.pgd); + + /* + * At this point we are running encrypted. Remove the mappings for + * the decrypted areas - all that is needed for this is to remove + * the PGD entry/entries. + */ + ppd.vaddr = kernel_start + decrypted_base; + ppd.vaddr_end = kernel_end + decrypted_base; + sme_clear_pgd(&ppd); + + if (initrd_len) { + ppd.vaddr = initrd_start + decrypted_base; + ppd.vaddr_end = initrd_end + decrypted_base; + sme_clear_pgd(&ppd); + } + + ppd.vaddr = workarea_start + decrypted_base; + ppd.vaddr_end = workarea_end + decrypted_base; + sme_clear_pgd(&ppd); + + /* Flush the TLB - no globals so cr3 is enough */ + native_write_cr3(__native_read_cr3()); +} + +void __init sme_enable(struct boot_params *bp) +{ + unsigned int eax, ebx, ecx, edx; + unsigned long feature_mask; + unsigned long me_mask; + bool snp_en; + u64 msr; + + snp_en = snp_init(bp); + + /* Check for the SME/SEV support leaf */ + eax = 0x80000000; + ecx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + if (eax < 0x8000001f) + return; + +#define AMD_SME_BIT BIT(0) +#define AMD_SEV_BIT BIT(1) + + /* + * Check for the SME/SEV feature: + * CPUID Fn8000_001F[EAX] + * - Bit 0 - Secure Memory Encryption support + * - Bit 1 - Secure Encrypted Virtualization support + * CPUID Fn8000_001F[EBX] + * - Bits 5:0 - Pagetable bit position used to indicate encryption + */ + eax = 0x8000001f; + ecx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + /* Check whether SEV or SME is supported */ + if (!(eax & (AMD_SEV_BIT | AMD_SME_BIT))) + return; + + me_mask = 1UL << (ebx & 0x3f); + sev_snp_needs_sfw = !(ebx & BIT(31)); + + /* Check the SEV MSR whether SEV or SME is enabled */ + sev_status = msr = native_rdmsrq(MSR_AMD64_SEV); + feature_mask = (msr & MSR_AMD64_SEV_ENABLED) ? AMD_SEV_BIT : AMD_SME_BIT; + + /* + * Any discrepancies between the presence of a CC blob and SNP + * enablement abort the guest. + */ + if (snp_en ^ !!(msr & MSR_AMD64_SEV_SNP_ENABLED)) + sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED); + + /* Check if memory encryption is enabled */ + if (feature_mask == AMD_SME_BIT) { + if (!(bp->hdr.xloadflags & XLF_MEM_ENCRYPTION)) + return; + + /* + * No SME if Hypervisor bit is set. This check is here to + * prevent a guest from trying to enable SME. For running as a + * KVM guest the MSR_AMD64_SYSCFG will be sufficient, but there + * might be other hypervisors which emulate that MSR as non-zero + * or even pass it through to the guest. + * A malicious hypervisor can still trick a guest into this + * path, but there is no way to protect against that. + */ + eax = 1; + ecx = 0; + native_cpuid(&eax, &ebx, &ecx, &edx); + if (ecx & BIT(31)) + return; + + /* For SME, check the SYSCFG MSR */ + msr = native_rdmsrq(MSR_AMD64_SYSCFG); + if (!(msr & MSR_AMD64_SYSCFG_MEM_ENCRYPT)) + return; + } + + sme_me_mask = me_mask; + physical_mask &= ~me_mask; + cc_vendor = CC_VENDOR_AMD; + cc_set_mask(me_mask); +} + +#ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION +/* Local version for startup code, which never operates on user page tables */ +pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) +{ + return pgd; +} +#endif diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c new file mode 100644 index 000000000..1632d40e1 --- /dev/null +++ b/arch/x86/boot/string.c @@ -0,0 +1,357 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Very basic string functions + */ + +#include <linux/types.h> +#include <linux/compiler.h> +#include <linux/errno.h> +#include <linux/limits.h> +#include <asm/asm.h> +#include "ctype.h" +#include "string.h" + +#define KSTRTOX_OVERFLOW (1U << 31) + +/* + * Undef these macros so that the functions that we provide + * here will have the correct names regardless of how string.h + * may have chosen to #define them. + */ +#undef memcpy +#undef memset +#undef memcmp + +int memcmp(const void *s1, const void *s2, size_t len) +{ + bool diff; + + /* + * Make sure ZF is properly set in the len==0 case because in it, + * RCX==0 and the REPE; CMPSB won't get executed. + */ + asm volatile("test %3, %3\n\t" + "repe cmpsb" + : "=@ccnz" (diff), "+D" (s1), "+S" (s2), "+c" (len) + : : "cc", "memory"); + return diff; +} + +/* + * Clang may lower `memcmp == 0` to `bcmp == 0`. + */ +int bcmp(const void *s1, const void *s2, size_t len) +{ + return memcmp(s1, s2, len); +} + +int strcmp(const char *str1, const char *str2) +{ + const unsigned char *s1 = (const unsigned char *)str1; + const unsigned char *s2 = (const unsigned char *)str2; + int delta; + + while (*s1 || *s2) { + delta = *s1 - *s2; + if (delta) + return delta; + s1++; + s2++; + } + return 0; +} + +int strncmp(const char *cs, const char *ct, size_t count) +{ + unsigned char c1, c2; + + while (count) { + c1 = *cs++; + c2 = *ct++; + if (c1 != c2) + return c1 < c2 ? -1 : 1; + if (!c1) + break; + count--; + } + return 0; +} + +size_t strnlen(const char *s, size_t maxlen) +{ + const char *es = s; + while (*es && maxlen) { + es++; + maxlen--; + } + + return (es - s); +} + +/* Works only for digits and letters, but small and fast */ +#define TOLOWER(x) ((x) | 0x20) + +static unsigned int simple_guess_base(const char *cp) +{ + if (cp[0] == '0') { + if (TOLOWER(cp[1]) == 'x' && isxdigit(cp[2])) + return 16; + else + return 8; + } else { + return 10; + } +} + +/** + * simple_strtoull - convert a string to an unsigned long long + * @cp: The start of the string + * @endp: A pointer to the end of the parsed string will be placed here + * @base: The number base to use + */ +unsigned long long simple_strtoull(const char *cp, char **endp, unsigned int base) +{ + unsigned long long result = 0; + + if (!base) + base = simple_guess_base(cp); + + if (base == 16 && cp[0] == '0' && TOLOWER(cp[1]) == 'x') + cp += 2; + + while (isxdigit(*cp)) { + unsigned int value; + + value = isdigit(*cp) ? *cp - '0' : TOLOWER(*cp) - 'a' + 10; + if (value >= base) + break; + result = result * base + value; + cp++; + } + if (endp) + *endp = (char *)cp; + + return result; +} + +long simple_strtol(const char *cp, char **endp, unsigned int base) +{ + if (*cp == '-') + return -simple_strtoull(cp + 1, endp, base); + + return simple_strtoull(cp, endp, base); +} + +/** + * strlen - Find the length of a string + * @s: The string to be sized + */ +size_t strlen(const char *s) +{ + const char *sc; + + for (sc = s; *sc != '\0'; ++sc) + /* nothing */; + return sc - s; +} + +/** + * strstr - Find the first substring in a %NUL terminated string + * @s1: The string to be searched + * @s2: The string to search for + */ +char *strstr(const char *s1, const char *s2) +{ + size_t l1, l2; + + l2 = strlen(s2); + if (!l2) + return (char *)s1; + l1 = strlen(s1); + while (l1 >= l2) { + l1--; + if (!memcmp(s1, s2, l2)) + return (char *)s1; + s1++; + } + return NULL; +} + +/** + * strchr - Find the first occurrence of the character c in the string s. + * @s: the string to be searched + * @c: the character to search for + */ +char *strchr(const char *s, int c) +{ + while (*s != (char)c) + if (*s++ == '\0') + return NULL; + return (char *)s; +} + +static inline u64 __div_u64_rem(u64 dividend, u32 divisor, u32 *remainder) +{ + union { + u64 v64; + u32 v32[2]; + } d = { dividend }; + u32 upper; + + upper = d.v32[1]; + d.v32[1] = 0; + if (upper >= divisor) { + d.v32[1] = upper / divisor; + upper %= divisor; + } + asm ("divl %2" : "=a" (d.v32[0]), "=d" (*remainder) : + "rm" (divisor), "0" (d.v32[0]), "1" (upper)); + return d.v64; +} + +static inline u64 __div_u64(u64 dividend, u32 divisor) +{ + u32 remainder; + + return __div_u64_rem(dividend, divisor, &remainder); +} + +static inline char _tolower(const char c) +{ + return c | 0x20; +} + +static const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) +{ + if (*base == 0) { + if (s[0] == '0') { + if (_tolower(s[1]) == 'x' && isxdigit(s[2])) + *base = 16; + else + *base = 8; + } else + *base = 10; + } + if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') + s += 2; + return s; +} + +/* + * Convert non-negative integer string representation in explicitly given radix + * to an integer. + * Return number of characters consumed maybe or-ed with overflow bit. + * If overflow occurs, result integer (incorrect) is still returned. + * + * Don't you dare use this function. + */ +static unsigned int _parse_integer(const char *s, + unsigned int base, + unsigned long long *p) +{ + unsigned long long res; + unsigned int rv; + + res = 0; + rv = 0; + while (1) { + unsigned int c = *s; + unsigned int lc = c | 0x20; /* don't tolower() this line */ + unsigned int val; + + if ('0' <= c && c <= '9') + val = c - '0'; + else if ('a' <= lc && lc <= 'f') + val = lc - 'a' + 10; + else + break; + + if (val >= base) + break; + /* + * Check for overflow only if we are within range of + * it in the max base we support (16) + */ + if (unlikely(res & (~0ull << 60))) { + if (res > __div_u64(ULLONG_MAX - val, base)) + rv |= KSTRTOX_OVERFLOW; + } + res = res * base + val; + rv++; + s++; + } + *p = res; + return rv; +} + +static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) +{ + unsigned long long _res; + unsigned int rv; + + if (s[0] == '+') + s++; + + s = _parse_integer_fixup_radix(s, &base); + rv = _parse_integer(s, base, &_res); + if (rv & KSTRTOX_OVERFLOW) + return -ERANGE; + if (rv == 0) + return -EINVAL; + s += rv; + if (*s == '\n') + s++; + if (*s) + return -EINVAL; + *res = _res; + return 0; +} + +static int _kstrtoul(const char *s, unsigned int base, unsigned long *res) +{ + unsigned long long tmp; + int rv; + + rv = _kstrtoull(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (unsigned long)tmp) + return -ERANGE; + *res = tmp; + return 0; +} + +/** + * boot_kstrtoul - convert a string to an unsigned long + * @s: The start of the string. The string must be null-terminated, and may also + * include a single newline before its terminating null. The first character + * may also be a plus sign, but not a minus sign. + * @base: The number base to use. The maximum supported base is 16. If base is + * given as 0, then the base of the string is automatically detected with the + * conventional semantics - If it begins with 0x the number will be parsed as a + * hexadecimal (case insensitive), if it otherwise begins with 0, it will be + * parsed as an octal number. Otherwise it will be parsed as a decimal. + * @res: Where to write the result of the conversion on success. + * + * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. + * Used as a replacement for the simple_strtoull. + */ +int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res) +{ + /* + * We want to shortcut function call, but + * __builtin_types_compatible_p(unsigned long, unsigned long long) = 0. + */ + if (sizeof(unsigned long) == sizeof(unsigned long long) && + __alignof__(unsigned long) == __alignof__(unsigned long long)) + return _kstrtoull(s, base, (unsigned long long *)res); + else + return _kstrtoul(s, base, res); +} diff --git a/arch/x86/boot/string.h b/arch/x86/boot/string.h new file mode 100644 index 000000000..4092bf2ed --- /dev/null +++ b/arch/x86/boot/string.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef BOOT_STRING_H +#define BOOT_STRING_H + +/* Undef any of these macros coming from string_32.h. */ +#undef memcpy +#undef memset +#undef memcmp + +void *memcpy(void *dst, const void *src, size_t len); +void *memmove(void *dst, const void *src, size_t len); +void *memset(void *dst, int c, size_t len); +int memcmp(const void *s1, const void *s2, size_t len); +int bcmp(const void *s1, const void *s2, size_t len); + +/* Access builtin version by default. */ +#define memcpy(d,s,l) __builtin_memcpy(d,s,l) +#define memset(d,c,l) __builtin_memset(d,c,l) +#define memcmp __builtin_memcmp + +extern int strcmp(const char *str1, const char *str2); +extern int strncmp(const char *cs, const char *ct, size_t count); +extern size_t strlen(const char *s); +extern char *strstr(const char *s1, const char *s2); +extern char *strchr(const char *s, int c); +extern size_t strnlen(const char *s, size_t maxlen); +extern unsigned long long simple_strtoull(const char *cp, char **endp, + unsigned int base); +long simple_strtol(const char *cp, char **endp, unsigned int base); + +int boot_kstrtoul(const char *s, unsigned int base, unsigned long *res); +#endif /* BOOT_STRING_H */ diff --git a/arch/x86/boot/tty.c b/arch/x86/boot/tty.c new file mode 100644 index 000000000..f7eb976b0 --- /dev/null +++ b/arch/x86/boot/tty.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Very simple screen and serial I/O + */ + +#include "boot.h" + +int early_serial_base; + +#define XMTRDY 0x20 + +#define TXR 0 /* Transmit register (WRITE) */ +#define LSR 5 /* Line Status */ + +/* + * These functions are in .inittext so they can be used to signal + * error during initialization. + */ + +static void __section(".inittext") serial_putchar(int ch) +{ + unsigned timeout = 0xffff; + + while ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout) + cpu_relax(); + + outb(ch, early_serial_base + TXR); +} + +static void __section(".inittext") bios_putchar(int ch) +{ + struct biosregs ireg; + + initregs(&ireg); + ireg.bx = 0x0007; + ireg.cx = 0x0001; + ireg.ah = 0x0e; + ireg.al = ch; + intcall(0x10, &ireg, NULL); +} + +void __section(".inittext") putchar(int ch) +{ + if (ch == '\n') + putchar('\r'); /* \n -> \r\n */ + + bios_putchar(ch); + + if (early_serial_base != 0) + serial_putchar(ch); +} + +void __section(".inittext") puts(const char *str) +{ + while (*str) + putchar(*str++); +} + +/* + * Read the CMOS clock through the BIOS, and return the + * seconds in BCD. + */ + +static u8 gettime(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ah = 0x02; + intcall(0x1a, &ireg, &oreg); + + return oreg.dh; +} + +/* + * Read from the keyboard + */ +int getchar(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + /* ireg.ah = 0x00; */ + intcall(0x16, &ireg, &oreg); + + return oreg.al; +} + +static int kbd_pending(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ah = 0x01; + intcall(0x16, &ireg, &oreg); + + return !(oreg.eflags & X86_EFLAGS_ZF); +} + +void kbd_flush(void) +{ + for (;;) { + if (!kbd_pending()) + break; + getchar(); + } +} + +int getchar_timeout(void) +{ + int cnt = 30; + int t0, t1; + + t0 = gettime(); + + while (cnt) { + if (kbd_pending()) + return getchar(); + + t1 = gettime(); + if (t0 != t1) { + cnt--; + t0 = t1; + } + } + + return 0; /* Timeout! */ +} + diff --git a/arch/x86/boot/version.c b/arch/x86/boot/version.c new file mode 100644 index 000000000..945383f0f --- /dev/null +++ b/arch/x86/boot/version.c @@ -0,0 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Kernel version string + */ + +#include "boot.h" +#include <generated/utsversion.h> +#include <generated/utsrelease.h> +#include <generated/compile.h> + +const char kernel_version[] = + UTS_RELEASE " (" LINUX_COMPILE_BY "@" LINUX_COMPILE_HOST ") " + UTS_VERSION; diff --git a/arch/x86/boot/vesa.h b/arch/x86/boot/vesa.h new file mode 100644 index 000000000..9e23fdffb --- /dev/null +++ b/arch/x86/boot/vesa.h @@ -0,0 +1,67 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* ----------------------------------------------------------------------- * + * + * Copyright 1999-2007 H. Peter Anvin - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +#ifndef BOOT_VESA_H +#define BOOT_VESA_H + +typedef struct { + u16 off, seg; +} far_ptr; + +/* VESA General Information table */ +struct vesa_general_info { + u32 signature; /* 0 Magic number = "VESA" */ + u16 version; /* 4 */ + far_ptr vendor_string; /* 6 */ + u32 capabilities; /* 10 */ + far_ptr video_mode_ptr; /* 14 */ + u16 total_memory; /* 18 */ + + u8 reserved[236]; /* 20 */ +} __attribute__ ((packed)); + +#define VESA_MAGIC ('V' + ('E' << 8) + ('S' << 16) + ('A' << 24)) + +struct vesa_mode_info { + u16 mode_attr; /* 0 */ + u8 win_attr[2]; /* 2 */ + u16 win_grain; /* 4 */ + u16 win_size; /* 6 */ + u16 win_seg[2]; /* 8 */ + far_ptr win_scheme; /* 12 */ + u16 logical_scan; /* 16 */ + + u16 h_res; /* 18 */ + u16 v_res; /* 20 */ + u8 char_width; /* 22 */ + u8 char_height; /* 23 */ + u8 memory_planes; /* 24 */ + u8 bpp; /* 25 */ + u8 banks; /* 26 */ + u8 memory_layout; /* 27 */ + u8 bank_size; /* 28 */ + u8 image_planes; /* 29 */ + u8 page_function; /* 30 */ + + u8 rmask; /* 31 */ + u8 rpos; /* 32 */ + u8 gmask; /* 33 */ + u8 gpos; /* 34 */ + u8 bmask; /* 35 */ + u8 bpos; /* 36 */ + u8 resv_mask; /* 37 */ + u8 resv_pos; /* 38 */ + u8 dcm_info; /* 39 */ + + u32 lfb_ptr; /* 40 Linear frame buffer address */ + u32 offscreen_ptr; /* 44 Offscreen memory address */ + u16 offscreen_size; /* 48 */ + + u8 reserved[206]; /* 50 */ +} __attribute__ ((packed)); + +#endif /* LIB_SYS_VESA_H */ diff --git a/arch/x86/boot/video-bios.c b/arch/x86/boot/video-bios.c new file mode 100644 index 000000000..6eb8c06bc --- /dev/null +++ b/arch/x86/boot/video-bios.c @@ -0,0 +1,126 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Standard video BIOS modes + * + * We have two options for this; silent and scanned. + */ + +#include "boot.h" +#include "video.h" + +static __videocard video_bios; + +/* Set a conventional BIOS mode */ +static int set_bios_mode(u8 mode); + +static int bios_set_mode(struct mode_info *mi) +{ + return set_bios_mode(mi->mode - VIDEO_FIRST_BIOS); +} + +static int set_bios_mode(u8 mode) +{ + struct biosregs ireg, oreg; + u8 new_mode; + + initregs(&ireg); + ireg.al = mode; /* AH=0x00 Set Video Mode */ + intcall(0x10, &ireg, NULL); + + ireg.ah = 0x0f; /* Get Current Video Mode */ + intcall(0x10, &ireg, &oreg); + + do_restore = 1; /* Assume video contents were lost */ + + /* Not all BIOSes are clean with the top bit */ + new_mode = oreg.al & 0x7f; + + if (new_mode == mode) + return 0; /* Mode change OK */ + +#ifndef _WAKEUP + if (new_mode != boot_params.screen_info.orig_video_mode) { + /* Mode setting failed, but we didn't end up where we + started. That's bad. Try to revert to the original + video mode. */ + ireg.ax = boot_params.screen_info.orig_video_mode; + intcall(0x10, &ireg, NULL); + } +#endif + return -1; +} + +static int bios_probe(void) +{ + u8 mode; +#ifdef _WAKEUP + u8 saved_mode = 0x03; +#else + u8 saved_mode = boot_params.screen_info.orig_video_mode; +#endif + u16 crtc; + struct mode_info *mi; + int nmodes = 0; + + if (adapter != ADAPTER_EGA && adapter != ADAPTER_VGA) + return 0; + + set_fs(0); + crtc = vga_crtc(); + + video_bios.modes = GET_HEAP(struct mode_info, 0); + + for (mode = 0x14; mode <= 0x7f; mode++) { + if (!heap_free(sizeof(struct mode_info))) + break; + + if (mode_defined(VIDEO_FIRST_BIOS+mode)) + continue; + + if (set_bios_mode(mode)) + continue; + + /* Try to verify that it's a text mode. */ + + /* Attribute Controller: make graphics controller disabled */ + if (in_idx(0x3c0, 0x10) & 0x01) + continue; + + /* Graphics Controller: verify Alpha addressing enabled */ + if (in_idx(0x3ce, 0x06) & 0x01) + continue; + + /* CRTC cursor location low should be zero(?) */ + if (in_idx(crtc, 0x0f)) + continue; + + mi = GET_HEAP(struct mode_info, 1); + mi->mode = VIDEO_FIRST_BIOS+mode; + mi->depth = 0; /* text */ + mi->x = rdfs16(0x44a); + mi->y = rdfs8(0x484)+1; + nmodes++; + } + + set_bios_mode(saved_mode); + + return nmodes; +} + +static __videocard video_bios = +{ + .card_name = "BIOS", + .probe = bios_probe, + .set_mode = bios_set_mode, + .unsafe = 1, + .xmode_first = VIDEO_FIRST_BIOS, + .xmode_n = 0x80, +}; diff --git a/arch/x86/boot/video-mode.c b/arch/x86/boot/video-mode.c new file mode 100644 index 000000000..9ada55dc1 --- /dev/null +++ b/arch/x86/boot/video-mode.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007-2008 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * arch/i386/boot/video-mode.c + * + * Set the video mode. This is separated out into a different + * file in order to be shared with the ACPI wakeup code. + */ + +#include "boot.h" +#include "video.h" +#include "vesa.h" + +#include <uapi/asm/boot.h> + +/* + * Common variables + */ +int adapter; /* 0=CGA/MDA/HGC, 1=EGA, 2=VGA+ */ +int force_x, force_y; /* Don't query the BIOS for cols/rows */ +int do_restore; /* Screen contents changed during mode flip */ +int graphic_mode; /* Graphic mode with linear frame buffer */ + +/* Probe the video drivers and have them generate their mode lists. */ +void probe_cards(int unsafe) +{ + struct card_info *card; + static u8 probed[2]; + + if (probed[unsafe]) + return; + + probed[unsafe] = 1; + + for (card = video_cards; card < video_cards_end; card++) { + if (card->unsafe == unsafe) { + if (card->probe) + card->nmodes = card->probe(); + else + card->nmodes = 0; + } + } +} + +/* Test if a mode is defined */ +int mode_defined(u16 mode) +{ + struct card_info *card; + struct mode_info *mi; + int i; + + for (card = video_cards; card < video_cards_end; card++) { + mi = card->modes; + for (i = 0; i < card->nmodes; i++, mi++) { + if (mi->mode == mode) + return 1; + } + } + + return 0; +} + +/* Set mode (without recalc) */ +static int raw_set_mode(u16 mode, u16 *real_mode) +{ + int nmode, i; + struct card_info *card; + struct mode_info *mi; + + /* Drop the recalc bit if set */ + mode &= ~VIDEO_RECALC; + + /* Scan for mode based on fixed ID, position, or resolution */ + nmode = 0; + for (card = video_cards; card < video_cards_end; card++) { + mi = card->modes; + for (i = 0; i < card->nmodes; i++, mi++) { + int visible = mi->x || mi->y; + + if ((mode == nmode && visible) || + mode == mi->mode || + mode == (mi->y << 8)+mi->x) { + *real_mode = mi->mode; + return card->set_mode(mi); + } + + if (visible) + nmode++; + } + } + + /* Nothing found? Is it an "exceptional" (unprobed) mode? */ + for (card = video_cards; card < video_cards_end; card++) { + if (mode >= card->xmode_first && + mode < card->xmode_first+card->xmode_n) { + struct mode_info mix; + *real_mode = mix.mode = mode; + mix.x = mix.y = 0; + return card->set_mode(&mix); + } + } + + /* Otherwise, failure... */ + return -1; +} + +/* + * Recalculate the vertical video cutoff (hack!) + */ +static void vga_recalc_vertical(void) +{ + unsigned int font_size, rows; + u16 crtc; + u8 pt, ov; + + set_fs(0); + font_size = rdfs8(0x485); /* BIOS: font size (pixels) */ + rows = force_y ? force_y : rdfs8(0x484)+1; /* Text rows */ + + rows *= font_size; /* Visible scan lines */ + rows--; /* ... minus one */ + + crtc = vga_crtc(); + + pt = in_idx(crtc, 0x11); + pt &= ~0x80; /* Unlock CR0-7 */ + out_idx(pt, crtc, 0x11); + + out_idx((u8)rows, crtc, 0x12); /* Lower height register */ + + ov = in_idx(crtc, 0x07); /* Overflow register */ + ov &= 0xbd; + ov |= (rows >> (8-1)) & 0x02; + ov |= (rows >> (9-6)) & 0x40; + out_idx(ov, crtc, 0x07); +} + +/* Set mode (with recalc if specified) */ +int set_mode(u16 mode) +{ + int rv; + u16 real_mode; + + /* Very special mode numbers... */ + if (mode == VIDEO_CURRENT_MODE) + return 0; /* Nothing to do... */ + else if (mode == NORMAL_VGA) + mode = VIDEO_80x25; + else if (mode == EXTENDED_VGA) + mode = VIDEO_8POINT; + + rv = raw_set_mode(mode, &real_mode); + if (rv) + return rv; + + if (mode & VIDEO_RECALC) + vga_recalc_vertical(); + + /* Save the canonical mode number for the kernel, not + an alias, size specification or menu position */ +#ifndef _WAKEUP + boot_params.hdr.vid_mode = real_mode; +#endif + return 0; +} diff --git a/arch/x86/boot/video-vesa.c b/arch/x86/boot/video-vesa.c new file mode 100644 index 000000000..c2c6d35e3 --- /dev/null +++ b/arch/x86/boot/video-vesa.c @@ -0,0 +1,279 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * VESA text modes + */ + +#include "boot.h" +#include "video.h" +#include "vesa.h" +#include "string.h" + +/* VESA information */ +static struct vesa_general_info vginfo; +static struct vesa_mode_info vminfo; + +static __videocard video_vesa; + +#ifndef _WAKEUP +static void vesa_store_mode_params_graphics(void); +#else /* _WAKEUP */ +static inline void vesa_store_mode_params_graphics(void) {} +#endif /* _WAKEUP */ + +static int vesa_probe(void) +{ + struct biosregs ireg, oreg; + u16 mode; + addr_t mode_ptr; + struct mode_info *mi; + int nmodes = 0; + + video_vesa.modes = GET_HEAP(struct mode_info, 0); + + initregs(&ireg); + ireg.ax = 0x4f00; + ireg.di = (size_t)&vginfo; + intcall(0x10, &ireg, &oreg); + + if (oreg.ax != 0x004f || + vginfo.signature != VESA_MAGIC || + vginfo.version < 0x0102) + return 0; /* Not present */ + + set_fs(vginfo.video_mode_ptr.seg); + mode_ptr = vginfo.video_mode_ptr.off; + + while ((mode = rdfs16(mode_ptr)) != 0xffff) { + mode_ptr += 2; + + if (!heap_free(sizeof(struct mode_info))) + break; /* Heap full, can't save mode info */ + + if (mode & ~0x1ff) + continue; + + memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */ + + ireg.ax = 0x4f01; + ireg.cx = mode; + ireg.di = (size_t)&vminfo; + intcall(0x10, &ireg, &oreg); + + if (oreg.ax != 0x004f) + continue; + + if ((vminfo.mode_attr & 0x15) == 0x05) { + /* Text Mode, TTY BIOS supported, + supported by hardware */ + mi = GET_HEAP(struct mode_info, 1); + mi->mode = mode + VIDEO_FIRST_VESA; + mi->depth = 0; /* text */ + mi->x = vminfo.h_res; + mi->y = vminfo.v_res; + nmodes++; + } else if ((vminfo.mode_attr & 0x99) == 0x99 && + (vminfo.memory_layout == 4 || + vminfo.memory_layout == 6) && + vminfo.memory_planes == 1) { +#ifdef CONFIG_BOOT_VESA_SUPPORT + /* Graphics mode, color, linear frame buffer + supported. Only register the mode if + if framebuffer is configured, however, + otherwise the user will be left without a screen. */ + mi = GET_HEAP(struct mode_info, 1); + mi->mode = mode + VIDEO_FIRST_VESA; + mi->depth = vminfo.bpp; + mi->x = vminfo.h_res; + mi->y = vminfo.v_res; + nmodes++; +#endif + } + } + + return nmodes; +} + +static int vesa_set_mode(struct mode_info *mode) +{ + struct biosregs ireg, oreg; + int is_graphic; + u16 vesa_mode = mode->mode - VIDEO_FIRST_VESA; + + memset(&vminfo, 0, sizeof(vminfo)); /* Just in case... */ + + initregs(&ireg); + ireg.ax = 0x4f01; + ireg.cx = vesa_mode; + ireg.di = (size_t)&vminfo; + intcall(0x10, &ireg, &oreg); + + if (oreg.ax != 0x004f) + return -1; + + if ((vminfo.mode_attr & 0x15) == 0x05) { + /* It's a supported text mode */ + is_graphic = 0; +#ifdef CONFIG_BOOT_VESA_SUPPORT + } else if ((vminfo.mode_attr & 0x99) == 0x99) { + /* It's a graphics mode with linear frame buffer */ + is_graphic = 1; + vesa_mode |= 0x4000; /* Request linear frame buffer */ +#endif + } else { + return -1; /* Invalid mode */ + } + + + initregs(&ireg); + ireg.ax = 0x4f02; + ireg.bx = vesa_mode; + intcall(0x10, &ireg, &oreg); + + if (oreg.ax != 0x004f) + return -1; + + graphic_mode = is_graphic; + if (!is_graphic) { + /* Text mode */ + force_x = mode->x; + force_y = mode->y; + do_restore = 1; + } else { + /* Graphics mode */ + vesa_store_mode_params_graphics(); + } + + return 0; +} + + +#ifndef _WAKEUP + +/* Switch DAC to 8-bit mode */ +static void vesa_dac_set_8bits(void) +{ + struct biosregs ireg, oreg; + u8 dac_size = 6; + + /* If possible, switch the DAC to 8-bit mode */ + if (vginfo.capabilities & 1) { + initregs(&ireg); + ireg.ax = 0x4f08; + ireg.bh = 0x08; + intcall(0x10, &ireg, &oreg); + if (oreg.ax == 0x004f) + dac_size = oreg.bh; + } + + /* Set the color sizes to the DAC size, and offsets to 0 */ + boot_params.screen_info.red_size = dac_size; + boot_params.screen_info.green_size = dac_size; + boot_params.screen_info.blue_size = dac_size; + boot_params.screen_info.rsvd_size = dac_size; + + boot_params.screen_info.red_pos = 0; + boot_params.screen_info.green_pos = 0; + boot_params.screen_info.blue_pos = 0; + boot_params.screen_info.rsvd_pos = 0; +} + +/* Save the VESA protected mode info */ +static void vesa_store_pm_info(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ax = 0x4f0a; + intcall(0x10, &ireg, &oreg); + + if (oreg.ax != 0x004f) + return; + + boot_params.screen_info.vesapm_seg = oreg.es; + boot_params.screen_info.vesapm_off = oreg.di; +} + +/* + * Save video mode parameters for graphics mode + */ +static void vesa_store_mode_params_graphics(void) +{ + /* Tell the kernel we're in VESA graphics mode */ + boot_params.screen_info.orig_video_isVGA = VIDEO_TYPE_VLFB; + + /* Mode parameters */ + boot_params.screen_info.vesa_attributes = vminfo.mode_attr; + boot_params.screen_info.lfb_linelength = vminfo.logical_scan; + boot_params.screen_info.lfb_width = vminfo.h_res; + boot_params.screen_info.lfb_height = vminfo.v_res; + boot_params.screen_info.lfb_depth = vminfo.bpp; + boot_params.screen_info.pages = vminfo.image_planes; + boot_params.screen_info.lfb_base = vminfo.lfb_ptr; + memcpy(&boot_params.screen_info.red_size, + &vminfo.rmask, 8); + + /* General parameters */ + boot_params.screen_info.lfb_size = vginfo.total_memory; + + if (vminfo.bpp <= 8) + vesa_dac_set_8bits(); + + vesa_store_pm_info(); +} + +/* + * Save EDID information for the kernel; this is invoked, separately, + * after mode-setting. + */ +void vesa_store_edid(void) +{ +#ifdef CONFIG_FIRMWARE_EDID + struct biosregs ireg, oreg; + + /* Apparently used as a nonsense token... */ + memset(&boot_params.edid_info, 0x13, sizeof(boot_params.edid_info)); + + if (vginfo.version < 0x0200) + return; /* EDID requires VBE 2.0+ */ + + initregs(&ireg); + ireg.ax = 0x4f15; /* VBE DDC */ + /* ireg.bx = 0x0000; */ /* Report DDC capabilities */ + /* ireg.cx = 0; */ /* Controller 0 */ + ireg.es = 0; /* ES:DI must be 0 by spec */ + intcall(0x10, &ireg, &oreg); + + if (oreg.ax != 0x004f) + return; /* No EDID */ + + /* BH = time in seconds to transfer EDD information */ + /* BL = DDC level supported */ + + ireg.ax = 0x4f15; /* VBE DDC */ + ireg.bx = 0x0001; /* Read EDID */ + /* ireg.cx = 0; */ /* Controller 0 */ + /* ireg.dx = 0; */ /* EDID block number */ + ireg.es = ds(); + ireg.di =(size_t)&boot_params.edid_info; /* (ES:)Pointer to block */ + intcall(0x10, &ireg, &oreg); +#endif /* CONFIG_FIRMWARE_EDID */ +} + +#endif /* not _WAKEUP */ + +static __videocard video_vesa = +{ + .card_name = "VESA", + .probe = vesa_probe, + .set_mode = vesa_set_mode, + .xmode_first = VIDEO_FIRST_VESA, + .xmode_n = 0x200, +}; diff --git a/arch/x86/boot/video-vga.c b/arch/x86/boot/video-vga.c new file mode 100644 index 000000000..4816cb9cf --- /dev/null +++ b/arch/x86/boot/video-vga.c @@ -0,0 +1,286 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Common all-VGA modes + */ + +#include "boot.h" +#include "video.h" + +static struct mode_info vga_modes[] = { + { VIDEO_80x25, 80, 25, 0 }, + { VIDEO_8POINT, 80, 50, 0 }, + { VIDEO_80x43, 80, 43, 0 }, + { VIDEO_80x28, 80, 28, 0 }, + { VIDEO_80x30, 80, 30, 0 }, + { VIDEO_80x34, 80, 34, 0 }, + { VIDEO_80x60, 80, 60, 0 }, +}; + +static struct mode_info ega_modes[] = { + { VIDEO_80x25, 80, 25, 0 }, + { VIDEO_8POINT, 80, 43, 0 }, +}; + +static struct mode_info cga_modes[] = { + { VIDEO_80x25, 80, 25, 0 }, +}; + +static __videocard video_vga; + +/* Set basic 80x25 mode */ +static u8 vga_set_basic_mode(void) +{ + struct biosregs ireg, oreg; + u8 mode; + + initregs(&ireg); + + /* Query current mode */ + ireg.ax = 0x0f00; + intcall(0x10, &ireg, &oreg); + mode = oreg.al; + + if (mode != 3 && mode != 7) + mode = 3; + + /* Set the mode */ + ireg.ax = mode; /* AH=0: set mode */ + intcall(0x10, &ireg, NULL); + do_restore = 1; + return mode; +} + +static void vga_set_8font(void) +{ + /* Set 8x8 font - 80x43 on EGA, 80x50 on VGA */ + struct biosregs ireg; + + initregs(&ireg); + + /* Set 8x8 font */ + ireg.ax = 0x1112; + /* ireg.bl = 0; */ + intcall(0x10, &ireg, NULL); + + /* Use alternate print screen */ + ireg.ax = 0x1200; + ireg.bl = 0x20; + intcall(0x10, &ireg, NULL); + + /* Turn off cursor emulation */ + ireg.ax = 0x1201; + ireg.bl = 0x34; + intcall(0x10, &ireg, NULL); + + /* Cursor is scan lines 6-7 */ + ireg.ax = 0x0100; + ireg.cx = 0x0607; + intcall(0x10, &ireg, NULL); +} + +static void vga_set_14font(void) +{ + /* Set 9x14 font - 80x28 on VGA */ + struct biosregs ireg; + + initregs(&ireg); + + /* Set 9x14 font */ + ireg.ax = 0x1111; + /* ireg.bl = 0; */ + intcall(0x10, &ireg, NULL); + + /* Turn off cursor emulation */ + ireg.ax = 0x1201; + ireg.bl = 0x34; + intcall(0x10, &ireg, NULL); + + /* Cursor is scan lines 11-12 */ + ireg.ax = 0x0100; + ireg.cx = 0x0b0c; + intcall(0x10, &ireg, NULL); +} + +static void vga_set_80x43(void) +{ + /* Set 80x43 mode on VGA (not EGA) */ + struct biosregs ireg; + + initregs(&ireg); + + /* Set 350 scans */ + ireg.ax = 0x1201; + ireg.bl = 0x30; + intcall(0x10, &ireg, NULL); + + /* Reset video mode */ + ireg.ax = 0x0003; + intcall(0x10, &ireg, NULL); + + vga_set_8font(); +} + +/* I/O address of the VGA CRTC */ +u16 vga_crtc(void) +{ + return (inb(0x3cc) & 1) ? 0x3d4 : 0x3b4; +} + +static void vga_set_480_scanlines(void) +{ + u16 crtc; /* CRTC base address */ + u8 csel; /* CRTC miscellaneous output register */ + + crtc = vga_crtc(); + + out_idx(0x0c, crtc, 0x11); /* Vertical sync end, unlock CR0-7 */ + out_idx(0x0b, crtc, 0x06); /* Vertical total */ + out_idx(0x3e, crtc, 0x07); /* Vertical overflow */ + out_idx(0xea, crtc, 0x10); /* Vertical sync start */ + out_idx(0xdf, crtc, 0x12); /* Vertical display end */ + out_idx(0xe7, crtc, 0x15); /* Vertical blank start */ + out_idx(0x04, crtc, 0x16); /* Vertical blank end */ + csel = inb(0x3cc); + csel &= 0x0d; + csel |= 0xe2; + outb(csel, 0x3c2); +} + +static void vga_set_vertical_end(int lines) +{ + u16 crtc; /* CRTC base address */ + u8 ovfw; /* CRTC overflow register */ + int end = lines-1; + + crtc = vga_crtc(); + + ovfw = 0x3c | ((end >> (8-1)) & 0x02) | ((end >> (9-6)) & 0x40); + + out_idx(ovfw, crtc, 0x07); /* Vertical overflow */ + out_idx(end, crtc, 0x12); /* Vertical display end */ +} + +static void vga_set_80x30(void) +{ + vga_set_480_scanlines(); + vga_set_vertical_end(30*16); +} + +static void vga_set_80x34(void) +{ + vga_set_480_scanlines(); + vga_set_14font(); + vga_set_vertical_end(34*14); +} + +static void vga_set_80x60(void) +{ + vga_set_480_scanlines(); + vga_set_8font(); + vga_set_vertical_end(60*8); +} + +static int vga_set_mode(struct mode_info *mode) +{ + /* Set the basic mode */ + vga_set_basic_mode(); + + /* Override a possibly broken BIOS */ + force_x = mode->x; + force_y = mode->y; + + switch (mode->mode) { + case VIDEO_80x25: + break; + case VIDEO_8POINT: + vga_set_8font(); + break; + case VIDEO_80x43: + vga_set_80x43(); + break; + case VIDEO_80x28: + vga_set_14font(); + break; + case VIDEO_80x30: + vga_set_80x30(); + break; + case VIDEO_80x34: + vga_set_80x34(); + break; + case VIDEO_80x60: + vga_set_80x60(); + break; + } + + return 0; +} + +/* + * Note: this probe includes basic information required by all + * systems. It should be executed first, by making sure + * video-vga.c is listed first in the Makefile. + */ +static int vga_probe(void) +{ + static const char *card_name[] = { + "CGA/MDA/HGC", "EGA", "VGA" + }; + static struct mode_info *mode_lists[] = { + cga_modes, + ega_modes, + vga_modes, + }; + static int mode_count[] = { + ARRAY_SIZE(cga_modes), + ARRAY_SIZE(ega_modes), + ARRAY_SIZE(vga_modes), + }; + + struct biosregs ireg, oreg; + + initregs(&ireg); + + ireg.ax = 0x1200; + ireg.bl = 0x10; /* Check EGA/VGA */ + intcall(0x10, &ireg, &oreg); + +#ifndef _WAKEUP + boot_params.screen_info.orig_video_ega_bx = oreg.bx; +#endif + + /* If we have MDA/CGA/HGC then BL will be unchanged at 0x10 */ + if (oreg.bl != 0x10) { + /* EGA/VGA */ + ireg.ax = 0x1a00; + intcall(0x10, &ireg, &oreg); + + if (oreg.al == 0x1a) { + adapter = ADAPTER_VGA; +#ifndef _WAKEUP + boot_params.screen_info.orig_video_isVGA = 1; +#endif + } else { + adapter = ADAPTER_EGA; + } + } else { + adapter = ADAPTER_CGA; + } + + video_vga.modes = mode_lists[adapter]; + video_vga.card_name = card_name[adapter]; + return mode_count[adapter]; +} + +static __videocard video_vga = { + .card_name = "VGA", + .probe = vga_probe, + .set_mode = vga_set_mode, +}; diff --git a/arch/x86/boot/video.c b/arch/x86/boot/video.c new file mode 100644 index 000000000..0641c8c46 --- /dev/null +++ b/arch/x86/boot/video.c @@ -0,0 +1,343 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * Copyright 2009 Intel Corporation; author H. Peter Anvin + * + * ----------------------------------------------------------------------- */ + +/* + * Select video mode + */ + +#include <uapi/asm/boot.h> + +#include "boot.h" +#include "video.h" +#include "vesa.h" + +static u16 video_segment; + +static void store_cursor_position(void) +{ + struct biosregs ireg, oreg; + + initregs(&ireg); + ireg.ah = 0x03; + intcall(0x10, &ireg, &oreg); + + boot_params.screen_info.orig_x = oreg.dl; + boot_params.screen_info.orig_y = oreg.dh; + + if (oreg.ch & 0x20) + boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR; + + if ((oreg.ch & 0x1f) > (oreg.cl & 0x1f)) + boot_params.screen_info.flags |= VIDEO_FLAGS_NOCURSOR; +} + +static void store_video_mode(void) +{ + struct biosregs ireg, oreg; + + /* N.B.: the saving of the video page here is a bit silly, + since we pretty much assume page 0 everywhere. */ + initregs(&ireg); + ireg.ah = 0x0f; + intcall(0x10, &ireg, &oreg); + + /* Not all BIOSes are clean with respect to the top bit */ + boot_params.screen_info.orig_video_mode = oreg.al & 0x7f; + boot_params.screen_info.orig_video_page = oreg.bh; +} + +/* + * Store the video mode parameters for later usage by the kernel. + * This is done by asking the BIOS except for the rows/columns + * parameters in the default 80x25 mode -- these are set directly, + * because some very obscure BIOSes supply insane values. + */ +static void store_mode_params(void) +{ + u16 font_size; + int x, y; + + /* For graphics mode, it is up to the mode-setting driver + (currently only video-vesa.c) to store the parameters */ + if (graphic_mode) + return; + + store_cursor_position(); + store_video_mode(); + + if (boot_params.screen_info.orig_video_mode == 0x07) { + /* MDA, HGC, or VGA in monochrome mode */ + video_segment = 0xb000; + } else { + /* CGA, EGA, VGA and so forth */ + video_segment = 0xb800; + } + + set_fs(0); + font_size = rdfs16(0x485); /* Font size, BIOS area */ + boot_params.screen_info.orig_video_points = font_size; + + x = rdfs16(0x44a); + y = (adapter == ADAPTER_CGA) ? 25 : rdfs8(0x484)+1; + + if (force_x) + x = force_x; + if (force_y) + y = force_y; + + boot_params.screen_info.orig_video_cols = x; + boot_params.screen_info.orig_video_lines = y; +} + +static unsigned int get_entry(void) +{ + char entry_buf[4]; + int i, len = 0; + int key; + unsigned int v; + + do { + key = getchar(); + + if (key == '\b') { + if (len > 0) { + puts("\b \b"); + len--; + } + } else if ((key >= '0' && key <= '9') || + (key >= 'A' && key <= 'Z') || + (key >= 'a' && key <= 'z')) { + if (len < sizeof(entry_buf)) { + entry_buf[len++] = key; + putchar(key); + } + } + } while (key != '\r'); + putchar('\n'); + + if (len == 0) + return VIDEO_CURRENT_MODE; /* Default */ + + v = 0; + for (i = 0; i < len; i++) { + v <<= 4; + key = entry_buf[i] | 0x20; + v += (key > '9') ? key-'a'+10 : key-'0'; + } + + return v; +} + +static void display_menu(void) +{ + struct card_info *card; + struct mode_info *mi; + char ch; + int i; + int nmodes; + int modes_per_line; + int col; + + nmodes = 0; + for (card = video_cards; card < video_cards_end; card++) + nmodes += card->nmodes; + + modes_per_line = 1; + if (nmodes >= 20) + modes_per_line = 3; + + for (col = 0; col < modes_per_line; col++) + puts("Mode: Resolution: Type: "); + putchar('\n'); + + col = 0; + ch = '0'; + for (card = video_cards; card < video_cards_end; card++) { + mi = card->modes; + for (i = 0; i < card->nmodes; i++, mi++) { + char resbuf[32]; + int visible = mi->x && mi->y; + u16 mode_id = mi->mode ? mi->mode : + (mi->y << 8)+mi->x; + + if (!visible) + continue; /* Hidden mode */ + + if (mi->depth) + sprintf(resbuf, "%dx%d", mi->y, mi->depth); + else + sprintf(resbuf, "%d", mi->y); + + printf("%c %03X %4dx%-7s %-6s", + ch, mode_id, mi->x, resbuf, card->card_name); + col++; + if (col >= modes_per_line) { + putchar('\n'); + col = 0; + } + + if (ch == '9') + ch = 'a'; + else if (ch == 'z' || ch == ' ') + ch = ' '; /* Out of keys... */ + else + ch++; + } + } + if (col) + putchar('\n'); +} + +#define H(x) ((x)-'a'+10) +#define SCAN ((H('s')<<12)+(H('c')<<8)+(H('a')<<4)+H('n')) + +static unsigned int mode_menu(void) +{ + int key; + unsigned int sel; + + puts("Press <ENTER> to see video modes available, " + "<SPACE> to continue, or wait 30 sec\n"); + + kbd_flush(); + while (1) { + key = getchar_timeout(); + if (key == ' ' || key == 0) + return VIDEO_CURRENT_MODE; /* Default */ + if (key == '\r') + break; + putchar('\a'); /* Beep! */ + } + + + for (;;) { + display_menu(); + + puts("Enter a video mode or \"scan\" to scan for " + "additional modes: "); + sel = get_entry(); + if (sel != SCAN) + return sel; + + probe_cards(1); + } +} + +/* Save screen content to the heap */ +static struct saved_screen { + int x, y; + int curx, cury; + u16 *data; +} saved; + +static void save_screen(void) +{ + /* Should be called after store_mode_params() */ + saved.x = boot_params.screen_info.orig_video_cols; + saved.y = boot_params.screen_info.orig_video_lines; + saved.curx = boot_params.screen_info.orig_x; + saved.cury = boot_params.screen_info.orig_y; + + if (!heap_free(saved.x*saved.y*sizeof(u16)+512)) + return; /* Not enough heap to save the screen */ + + saved.data = GET_HEAP(u16, saved.x*saved.y); + + set_fs(video_segment); + copy_from_fs(saved.data, 0, saved.x*saved.y*sizeof(u16)); +} + +static void restore_screen(void) +{ + /* Should be called after store_mode_params() */ + int xs = boot_params.screen_info.orig_video_cols; + int ys = boot_params.screen_info.orig_video_lines; + int y; + addr_t dst = 0; + u16 *src = saved.data; + struct biosregs ireg; + + if (graphic_mode) + return; /* Can't restore onto a graphic mode */ + + if (!src) + return; /* No saved screen contents */ + + /* Restore screen contents */ + + set_fs(video_segment); + for (y = 0; y < ys; y++) { + int npad; + + if (y < saved.y) { + int copy = (xs < saved.x) ? xs : saved.x; + copy_to_fs(dst, src, copy*sizeof(u16)); + dst += copy*sizeof(u16); + src += saved.x; + npad = (xs < saved.x) ? 0 : xs-saved.x; + } else { + npad = xs; + } + + /* Writes "npad" blank characters to + video_segment:dst and advances dst */ + asm volatile("pushw %%es ; " + "movw %2,%%es ; " + "shrw %%cx ; " + "jnc 1f ; " + "stosw \n\t" + "1: rep stosl ; " + "popw %%es" + : "+D" (dst), "+c" (npad) + : "bdS" (video_segment), + "a" (0x07200720)); + } + + /* Restore cursor position */ + if (saved.curx >= xs) + saved.curx = xs-1; + if (saved.cury >= ys) + saved.cury = ys-1; + + initregs(&ireg); + ireg.ah = 0x02; /* Set cursor position */ + ireg.dh = saved.cury; + ireg.dl = saved.curx; + intcall(0x10, &ireg, NULL); + + store_cursor_position(); +} + +void set_video(void) +{ + u16 mode = boot_params.hdr.vid_mode; + + RESET_HEAP(); + + store_mode_params(); + save_screen(); + probe_cards(0); + + for (;;) { + if (mode == ASK_VGA) + mode = mode_menu(); + + if (!set_mode(mode)) + break; + + printf("Undefined video mode number: %x\n", mode); + mode = ASK_VGA; + } + boot_params.hdr.vid_mode = mode; + vesa_store_edid(); + store_mode_params(); + + if (do_restore) + restore_screen(); +} diff --git a/arch/x86/boot/video.h b/arch/x86/boot/video.h new file mode 100644 index 000000000..04bde0bb2 --- /dev/null +++ b/arch/x86/boot/video.h @@ -0,0 +1,118 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * ----------------------------------------------------------------------- */ + +/* + * Header file for the real-mode video probing code + */ + +#ifndef BOOT_VIDEO_H +#define BOOT_VIDEO_H + +#include <linux/types.h> + +/* + * This code uses an extended set of video mode numbers. These include: + * Aliases for standard modes + * NORMAL_VGA (-1) + * EXTENDED_VGA (-2) + * ASK_VGA (-3) + * Video modes numbered by menu position -- NOT RECOMMENDED because of lack + * of compatibility when extending the table. These are between 0x00 and 0xff. + */ +#define VIDEO_FIRST_MENU 0x0000 + +/* Standard BIOS video modes (BIOS number + 0x0100) */ +#define VIDEO_FIRST_BIOS 0x0100 + +/* VESA BIOS video modes (VESA number + 0x0200) */ +#define VIDEO_FIRST_VESA 0x0200 + +/* Video7 special modes (BIOS number + 0x0900) */ +#define VIDEO_FIRST_V7 0x0900 + +/* Special video modes */ +#define VIDEO_FIRST_SPECIAL 0x0f00 +#define VIDEO_80x25 0x0f00 +#define VIDEO_8POINT 0x0f01 +#define VIDEO_80x43 0x0f02 +#define VIDEO_80x28 0x0f03 +#define VIDEO_CURRENT_MODE 0x0f04 +#define VIDEO_80x30 0x0f05 +#define VIDEO_80x34 0x0f06 +#define VIDEO_80x60 0x0f07 +#define VIDEO_GFX_HACK 0x0f08 +#define VIDEO_LAST_SPECIAL 0x0f09 + +/* Video modes given by resolution */ +#define VIDEO_FIRST_RESOLUTION 0x1000 + +/* The "recalculate timings" flag */ +#define VIDEO_RECALC 0x8000 + +void store_screen(void); +#define DO_STORE() store_screen() + +/* + * Mode table structures + */ + +struct mode_info { + u16 mode; /* Mode number (vga= style) */ + u16 x, y; /* Width, height */ + u16 depth; /* Bits per pixel, 0 for text mode */ +}; + +struct card_info { + const char *card_name; + int (*set_mode)(struct mode_info *mode); + int (*probe)(void); + struct mode_info *modes; + int nmodes; /* Number of probed modes so far */ + int unsafe; /* Probing is unsafe, only do after "scan" */ + u16 xmode_first; /* Unprobed modes to try to call anyway */ + u16 xmode_n; /* Size of unprobed mode range */ +}; + +#define __videocard struct card_info __section(".videocards") __attribute__((used)) +extern struct card_info video_cards[], video_cards_end[]; + +int mode_defined(u16 mode); /* video.c */ + +/* Basic video information */ +#define ADAPTER_CGA 0 /* CGA/MDA/HGC */ +#define ADAPTER_EGA 1 +#define ADAPTER_VGA 2 + +extern int adapter; +extern int force_x, force_y; /* Don't query the BIOS for cols/rows */ +extern int do_restore; /* Restore screen contents */ +extern int graphic_mode; /* Graphics mode with linear frame buffer */ + +/* Accessing VGA indexed registers */ +static inline u8 in_idx(u16 port, u8 index) +{ + outb(index, port); + return inb(port+1); +} + +static inline void out_idx(u8 v, u16 port, u8 index) +{ + outw(index+(v << 8), port); +} + +/* Writes a value to an indexed port and then reads the port again */ +static inline u8 tst_idx(u8 v, u16 port, u8 index) +{ + out_idx(port, index, v); + return in_idx(port, index); +} + +/* Get the I/O port of the VGA CRTC */ +u16 vga_crtc(void); /* video-vga.c */ + +#endif /* BOOT_VIDEO_H */ |
