From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/powerpc/boot/ps3.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 139 insertions(+) create mode 100644 arch/powerpc/boot/ps3.c (limited to 'arch/powerpc/boot/ps3.c') diff --git a/arch/powerpc/boot/ps3.c b/arch/powerpc/boot/ps3.c new file mode 100644 index 000000000..89ff46b8b --- /dev/null +++ b/arch/powerpc/boot/ps3.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * PS3 bootwrapper support. + * + * Copyright (C) 2007 Sony Computer Entertainment Inc. + * Copyright 2007 Sony Corp. + */ + +#include +#include +#include "types.h" +#include "elf.h" +#include "string.h" +#include "stdio.h" +#include "page.h" +#include "ops.h" + +extern int lv1_panic(u64 in_1); +extern int lv1_get_logical_partition_id(u64 *out_1); +extern int lv1_get_logical_ppe_id(u64 *out_1); +extern int lv1_get_repository_node_value(u64 in_1, u64 in_2, u64 in_3, + u64 in_4, u64 in_5, u64 *out_1, u64 *out_2); + +BSS_STACK(4096); + +/* A buffer that may be edited by tools operating on a zImage binary so as to + * edit the command line passed to vmlinux (by setting /chosen/bootargs). + * The buffer is put in its own section so that tools may locate it easier. + */ + +static char cmdline[BOOT_COMMAND_LINE_SIZE] + __attribute__((__section__("__builtin_cmdline"))); + +static void prep_cmdline(void *chosen) +{ + if (cmdline[0] == '\0') + getprop(chosen, "bootargs", cmdline, BOOT_COMMAND_LINE_SIZE-1); + else + setprop_str(chosen, "bootargs", cmdline); + + printf("cmdline: '%s'\n", cmdline); +} + +static void ps3_console_write(const char *buf, int len) +{ +} + +static void ps3_exit(void) +{ + printf("ps3_exit\n"); + + /* lv1_panic will shutdown the lpar. */ + + lv1_panic(0); /* zero = do not reboot */ + while (1); +} + +static int ps3_repository_read_rm_size(u64 *rm_size) +{ + int result; + u64 lpar_id; + u64 ppe_id; + u64 v2; + + result = lv1_get_logical_partition_id(&lpar_id); + + if (result) + return -1; + + result = lv1_get_logical_ppe_id(&ppe_id); + + if (result) + return -1; + + /* + * n1: 0000000062690000 : ....bi.. + * n2: 7075000000000000 : pu...... + * n3: 0000000000000001 : ........ + * n4: 726d5f73697a6500 : rm_size. + */ + + result = lv1_get_repository_node_value(lpar_id, 0x0000000062690000ULL, + 0x7075000000000000ULL, ppe_id, 0x726d5f73697a6500ULL, rm_size, + &v2); + + printf("%s:%d: ppe_id %lu \n", __func__, __LINE__, + (unsigned long)ppe_id); + printf("%s:%d: lpar_id %lu \n", __func__, __LINE__, + (unsigned long)lpar_id); + printf("%s:%d: rm_size %llxh \n", __func__, __LINE__, *rm_size); + + return result ? -1 : 0; +} + +void ps3_copy_vectors(void) +{ + extern char __system_reset_kernel[]; + + memcpy((void *)0x100, __system_reset_kernel, 512); + flush_cache((void *)0x100, 512); +} + +void platform_init(void) +{ + const u32 heapsize = 0x1000000 - (u32)_end; /* 16MiB */ + void *chosen; + unsigned long ft_addr; + u64 rm_size; + + console_ops.write = ps3_console_write; + platform_ops.exit = ps3_exit; + + printf("\n-- PS3 bootwrapper --\n"); + + simple_alloc_init(_end, heapsize, 32, 64); + fdt_init(_dtb_start); + + chosen = finddevice("/chosen"); + + ps3_repository_read_rm_size(&rm_size); + dt_fixup_memory(0, rm_size); + + if (&_initrd_end > &_initrd_start) { + setprop_val(chosen, "linux,initrd-start", (u32)(_initrd_start)); + setprop_val(chosen, "linux,initrd-end", (u32)(_initrd_end)); + } + + prep_cmdline(chosen); + + ft_addr = dt_ops.finalize(); + + ps3_copy_vectors(); + + printf(" flat tree at 0x%lx\n\r", ft_addr); + + ((kernel_entry_t)0)(ft_addr, 0, NULL); + + ps3_exit(); +} -- cgit v1.3.1