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/xtensa/mm/init.c | 202 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 202 insertions(+) create mode 100644 arch/xtensa/mm/init.c (limited to 'arch/xtensa/mm/init.c') diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c new file mode 100644 index 000000000..fe83a6833 --- /dev/null +++ b/arch/xtensa/mm/init.c @@ -0,0 +1,202 @@ +/* + * arch/xtensa/mm/init.c + * + * Derived from MIPS, PPC. + * + * 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) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2014 - 2016 Cadence Design Systems Inc. + * + * Chris Zankel + * Joe Taylor + * Marc Gauthier + * Kevin Chea + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +/* + * Initialize the bootmem system and give it all low memory we have available. + */ + +void __init bootmem_init(void) +{ + /* Reserve all memory below PHYS_OFFSET, as memory + * accounting doesn't work for pages below that address. + * + * If PHYS_OFFSET is zero reserve page at address 0: + * successfull allocations should never return NULL. + */ + memblock_reserve(0, PHYS_OFFSET ? PHYS_OFFSET : 1); + + early_init_fdt_scan_reserved_mem(); + + if (!memblock_phys_mem_size()) + panic("No memory found!\n"); + + min_low_pfn = PFN_UP(memblock_start_of_DRAM()); + min_low_pfn = max(min_low_pfn, PFN_UP(PHYS_OFFSET)); + max_pfn = PFN_DOWN(memblock_end_of_DRAM()); + max_low_pfn = min(max_pfn, MAX_LOW_PFN); + + early_memtest((phys_addr_t)min_low_pfn << PAGE_SHIFT, + (phys_addr_t)max_low_pfn << PAGE_SHIFT); + + memblock_set_current_limit(PFN_PHYS(max_low_pfn)); + dma_contiguous_reserve(PFN_PHYS(max_low_pfn)); + + memblock_dump_all(); +} + +static void __init print_vm_layout(void) +{ + pr_info("virtual kernel memory layout:\n" +#ifdef CONFIG_KASAN + " kasan : 0x%08lx - 0x%08lx (%5lu MB)\n" +#endif +#ifdef CONFIG_MMU + " vmalloc : 0x%08lx - 0x%08lx (%5lu MB)\n" +#endif +#ifdef CONFIG_HIGHMEM + " pkmap : 0x%08lx - 0x%08lx (%5lu kB)\n" + " fixmap : 0x%08lx - 0x%08lx (%5lu kB)\n" +#endif + " lowmem : 0x%08lx - 0x%08lx (%5lu MB)\n" + " .text : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .rodata : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .data : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .init : 0x%08lx - 0x%08lx (%5lu kB)\n" + " .bss : 0x%08lx - 0x%08lx (%5lu kB)\n", +#ifdef CONFIG_KASAN + KASAN_SHADOW_START, KASAN_SHADOW_START + KASAN_SHADOW_SIZE, + KASAN_SHADOW_SIZE >> 20, +#endif +#ifdef CONFIG_MMU + VMALLOC_START, VMALLOC_END, + (VMALLOC_END - VMALLOC_START) >> 20, +#ifdef CONFIG_HIGHMEM + PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE, + (LAST_PKMAP*PAGE_SIZE) >> 10, + FIXADDR_START, FIXADDR_END, + (FIXADDR_END - FIXADDR_START) >> 10, +#endif + PAGE_OFFSET, PAGE_OFFSET + + (max_low_pfn - min_low_pfn) * PAGE_SIZE, +#else + min_low_pfn * PAGE_SIZE, max_low_pfn * PAGE_SIZE, +#endif + ((max_low_pfn - min_low_pfn) * PAGE_SIZE) >> 20, + (unsigned long)_text, (unsigned long)_etext, + (unsigned long)(_etext - _text) >> 10, + (unsigned long)__start_rodata, (unsigned long)__end_rodata, + (unsigned long)(__end_rodata - __start_rodata) >> 10, + (unsigned long)_sdata, (unsigned long)_edata, + (unsigned long)(_edata - _sdata) >> 10, + (unsigned long)__init_begin, (unsigned long)__init_end, + (unsigned long)(__init_end - __init_begin) >> 10, + (unsigned long)__bss_start, (unsigned long)__bss_stop, + (unsigned long)(__bss_stop - __bss_start) >> 10); +} + +void __init arch_zone_limits_init(unsigned long *max_zone_pfns) +{ + max_zone_pfns[ZONE_NORMAL] = max_low_pfn; +#ifdef CONFIG_HIGHMEM + max_zone_pfns[ZONE_HIGHMEM] = max_pfn; +#endif +} + +void __init zones_init(void) +{ + print_vm_layout(); +} + +static void __init parse_memmap_one(char *p) +{ + char *oldp; + unsigned long start_at, mem_size; + + if (!p) + return; + + oldp = p; + mem_size = memparse(p, &p); + if (p == oldp) + return; + + switch (*p) { + case '@': + start_at = memparse(p + 1, &p); + memblock_add(start_at, mem_size); + break; + + case '$': + start_at = memparse(p + 1, &p); + memblock_reserve(start_at, mem_size); + break; + + case 0: + memblock_reserve(mem_size, -mem_size); + break; + + default: + pr_warn("Unrecognized memmap syntax: %s\n", p); + break; + } +} + +static int __init parse_memmap_opt(char *str) +{ + while (str) { + char *k = strchr(str, ','); + + if (k) + *k++ = 0; + + parse_memmap_one(str); + str = k; + } + + return 0; +} +early_param("memmap", parse_memmap_opt); + +#ifdef CONFIG_MMU +static const pgprot_t protection_map[16] = { + [VM_NONE] = PAGE_NONE, + [VM_READ] = PAGE_READONLY, + [VM_WRITE] = PAGE_COPY, + [VM_WRITE | VM_READ] = PAGE_COPY, + [VM_EXEC] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_EXEC | VM_WRITE] = PAGE_COPY_EXEC, + [VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY_EXEC, + [VM_SHARED] = PAGE_NONE, + [VM_SHARED | VM_READ] = PAGE_READONLY, + [VM_SHARED | VM_WRITE] = PAGE_SHARED, + [VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED, + [VM_SHARED | VM_EXEC] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED_EXEC, + [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED_EXEC +}; +DECLARE_VM_GET_PAGE_PROT +#endif -- cgit v1.3.1