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/microblaze/mm/pgtable.c | 264 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 arch/microblaze/mm/pgtable.c (limited to 'arch/microblaze/mm/pgtable.c') diff --git a/arch/microblaze/mm/pgtable.c b/arch/microblaze/mm/pgtable.c new file mode 100644 index 000000000..e96dd1b7a --- /dev/null +++ b/arch/microblaze/mm/pgtable.c @@ -0,0 +1,264 @@ +/* + * This file contains the routines setting up the linux page tables. + * + * Copyright (C) 2008 Michal Simek + * Copyright (C) 2008 PetaLogix + * + * Copyright (C) 2007 Xilinx, Inc. All rights reserved. + * + * Derived from arch/ppc/mm/pgtable.c: + * -- paulus + * + * Derived from arch/ppc/mm/init.c: + * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) + * + * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) + * and Cort Dougan (PReP) (cort@cs.nmt.edu) + * Copyright (C) 1996 Paul Mackerras + * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). + * + * Derived from "arch/i386/mm/init.c" + * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds + * + * 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. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +unsigned long ioremap_base; +unsigned long ioremap_bot; +EXPORT_SYMBOL(ioremap_bot); + +static void __iomem *__ioremap(phys_addr_t addr, unsigned long size, + unsigned long flags) +{ + unsigned long v, i; + phys_addr_t p; + int err; + + /* + * Choose an address to map it to. + * Once the vmalloc system is running, we use it. + * Before then, we use space going down from ioremap_base + * (ioremap_bot records where we're up to). + */ + p = addr & PAGE_MASK; + size = PAGE_ALIGN(addr + size) - p; + + /* + * Don't allow anybody to remap normal RAM that we're using. + * mem_init() sets high_memory so only do the check after that. + * + * However, allow remap of rootfs: TBD + */ + + if (mem_init_done && + p >= memory_start && p < virt_to_phys(high_memory) && + !(p >= __virt_to_phys((phys_addr_t)__bss_stop) && + p < __virt_to_phys((phys_addr_t)__bss_stop))) { + pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %ps\n", + (unsigned long)p, __builtin_return_address(0)); + return NULL; + } + + if (size == 0) + return NULL; + + /* + * Is it already mapped? If the whole area is mapped then we're + * done, otherwise remap it since we want to keep the virt addrs for + * each request contiguous. + * + * We make the assumption here that if the bottom and top + * of the range we want are mapped then it's mapped to the + * same virt address (and this is contiguous). + * -- Cort + */ + + if (mem_init_done) { + struct vm_struct *area; + area = get_vm_area(size, VM_IOREMAP); + if (area == NULL) + return NULL; + v = (unsigned long) area->addr; + } else { + v = (ioremap_bot -= size); + } + + if ((flags & _PAGE_PRESENT) == 0) + flags |= _PAGE_KERNEL; + if (flags & _PAGE_NO_CACHE) + flags |= _PAGE_GUARDED; + + err = 0; + for (i = 0; i < size && err == 0; i += PAGE_SIZE) + err = map_page(v + i, p + i, flags); + if (err) { + if (mem_init_done) + vfree((void *)v); + return NULL; + } + + return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); +} + +void __iomem *ioremap(phys_addr_t addr, unsigned long size) +{ + return __ioremap(addr, size, _PAGE_NO_CACHE); +} +EXPORT_SYMBOL(ioremap); + +void iounmap(volatile void __iomem *addr) +{ + if ((__force void *)addr > high_memory && + (unsigned long) addr < ioremap_bot) + vfree((void *) (PAGE_MASK & (unsigned long) addr)); +} +EXPORT_SYMBOL(iounmap); + + +int map_page(unsigned long va, phys_addr_t pa, int flags) +{ + p4d_t *p4d; + pud_t *pud; + pmd_t *pd; + pte_t *pg; + int err = -ENOMEM; + + /* Use upper 10 bits of VA to index the first level map */ + p4d = p4d_offset(pgd_offset_k(va), va); + pud = pud_offset(p4d, va); + pd = pmd_offset(pud, va); + /* Use middle 10 bits of VA to index the second-level map */ + pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */ + /* pg = pte_alloc_kernel(&init_mm, pd, va); */ + + if (pg != NULL) { + err = 0; + set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, + __pgprot(flags))); + if (unlikely(mem_init_done)) + _tlbie(va); + } + return err; +} + +/* + * Map in all of physical memory starting at CONFIG_KERNEL_START. + */ +void __init mapin_ram(void) +{ + unsigned long v, p, s, f; + + v = CONFIG_KERNEL_START; + p = memory_start; + for (s = 0; s < lowmem_size; s += PAGE_SIZE) { + f = _PAGE_PRESENT | _PAGE_ACCESSED | + _PAGE_SHARED | _PAGE_HWEXEC; + if (!is_kernel_text(v)) + f |= _PAGE_WRENABLE; + else + /* On the MicroBlaze, no user access + forces R/W kernel access */ + f |= _PAGE_USER; + map_page(v, p, f); + v += PAGE_SIZE; + p += PAGE_SIZE; + } +} + +/* is x a power of 2? */ +#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) + +/* Scan the real Linux page tables and return a PTE pointer for + * a virtual address in a context. + * Returns true (1) if PTE was found, zero otherwise. The pointer to + * the PTE pointer is unmodified if PTE is not found. + */ +static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) +{ + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte; + int retval = 0; + + pgd = pgd_offset(mm, addr & PAGE_MASK); + if (pgd) { + p4d = p4d_offset(pgd, addr & PAGE_MASK); + pud = pud_offset(p4d, addr & PAGE_MASK); + pmd = pmd_offset(pud, addr & PAGE_MASK); + if (pmd_present(*pmd)) { + pte = pte_offset_kernel(pmd, addr & PAGE_MASK); + if (pte) { + retval = 1; + *ptep = pte; + } + } + } + return retval; +} + +/* Find physical address for this virtual address. Normally used by + * I/O functions, but anyone can call it. + */ +unsigned long iopa(unsigned long addr) +{ + unsigned long pa; + + pte_t *pte; + struct mm_struct *mm; + + /* Allow mapping of user addresses (within the thread) + * for DMA if necessary. + */ + if (addr < TASK_SIZE) + mm = current->mm; + else + mm = &init_mm; + + pa = 0; + if (get_pteptr(mm, addr, &pte)) + pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); + + return pa; +} + +__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm) +{ + if (mem_init_done) + return __pte_alloc_one_kernel(mm); + else + return memblock_alloc_try_nid(PAGE_SIZE, PAGE_SIZE, + MEMBLOCK_LOW_LIMIT, + memory_start + kernel_tlb, + NUMA_NO_NODE); +} + +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) +{ + unsigned long address = __fix_to_virt(idx); + + if (idx >= __end_of_fixed_addresses) + BUG(); + + map_page(address, phys, pgprot_val(flags)); +} -- cgit v1.3.1