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 --- scripts/elf-parse.h | 305 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 305 insertions(+) create mode 100644 scripts/elf-parse.h (limited to 'scripts/elf-parse.h') diff --git a/scripts/elf-parse.h b/scripts/elf-parse.h new file mode 100644 index 000000000..f4411e030 --- /dev/null +++ b/scripts/elf-parse.h @@ -0,0 +1,305 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef _SCRIPTS_ELF_PARSE_H +#define _SCRIPTS_ELF_PARSE_H + +#include + +#include +#include + +typedef union { + Elf32_Ehdr e32; + Elf64_Ehdr e64; +} Elf_Ehdr; + +typedef union { + Elf32_Shdr e32; + Elf64_Shdr e64; +} Elf_Shdr; + +typedef union { + Elf32_Sym e32; + Elf64_Sym e64; +} Elf_Sym; + +typedef union { + Elf32_Rela e32; + Elf64_Rela e64; +} Elf_Rela; + +struct elf_funcs { + int (*compare_extable)(const void *a, const void *b); + uint64_t (*ehdr_shoff)(Elf_Ehdr *ehdr); + uint16_t (*ehdr_shstrndx)(Elf_Ehdr *ehdr); + uint16_t (*ehdr_shentsize)(Elf_Ehdr *ehdr); + uint16_t (*ehdr_shnum)(Elf_Ehdr *ehdr); + uint64_t (*shdr_addr)(Elf_Shdr *shdr); + uint64_t (*shdr_offset)(Elf_Shdr *shdr); + uint64_t (*shdr_size)(Elf_Shdr *shdr); + uint64_t (*shdr_entsize)(Elf_Shdr *shdr); + uint32_t (*shdr_link)(Elf_Shdr *shdr); + uint32_t (*shdr_name)(Elf_Shdr *shdr); + uint32_t (*shdr_type)(Elf_Shdr *shdr); + uint8_t (*sym_type)(Elf_Sym *sym); + uint32_t (*sym_name)(Elf_Sym *sym); + uint64_t (*sym_value)(Elf_Sym *sym); + uint16_t (*sym_shndx)(Elf_Sym *sym); + uint64_t (*rela_offset)(Elf_Rela *rela); + uint64_t (*rela_info)(Elf_Rela *rela); + uint64_t (*rela_addend)(Elf_Rela *rela); + void (*rela_write_addend)(Elf_Rela *rela, uint64_t val); + uint32_t (*r)(const uint32_t *); + uint16_t (*r2)(const uint16_t *); + uint64_t (*r8)(const uint64_t *); + void (*w)(uint32_t, uint32_t *); + void (*w8)(uint64_t, uint64_t *); +}; + +extern struct elf_funcs elf_parser; + +static inline uint64_t ehdr64_shoff(Elf_Ehdr *ehdr) +{ + return elf_parser.r8(&ehdr->e64.e_shoff); +} + +static inline uint64_t ehdr32_shoff(Elf_Ehdr *ehdr) +{ + return elf_parser.r(&ehdr->e32.e_shoff); +} + +static inline uint64_t ehdr_shoff(Elf_Ehdr *ehdr) +{ + return elf_parser.ehdr_shoff(ehdr); +} + +#define EHDR_HALF(fn_name) \ +static inline uint16_t ehdr64_##fn_name(Elf_Ehdr *ehdr) \ +{ \ + return elf_parser.r2(&ehdr->e64.e_##fn_name); \ +} \ + \ +static inline uint16_t ehdr32_##fn_name(Elf_Ehdr *ehdr) \ +{ \ + return elf_parser.r2(&ehdr->e32.e_##fn_name); \ +} \ + \ +static inline uint16_t ehdr_##fn_name(Elf_Ehdr *ehdr) \ +{ \ + return elf_parser.ehdr_##fn_name(ehdr); \ +} + +EHDR_HALF(shentsize) +EHDR_HALF(shstrndx) +EHDR_HALF(shnum) + +#define SHDR_WORD(fn_name) \ +static inline uint32_t shdr64_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.r(&shdr->e64.sh_##fn_name); \ +} \ + \ +static inline uint32_t shdr32_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.r(&shdr->e32.sh_##fn_name); \ +} \ + \ +static inline uint32_t shdr_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.shdr_##fn_name(shdr); \ +} + +#define SHDR_ADDR(fn_name) \ +static inline uint64_t shdr64_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.r8(&shdr->e64.sh_##fn_name); \ +} \ + \ +static inline uint64_t shdr32_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.r(&shdr->e32.sh_##fn_name); \ +} \ + \ +static inline uint64_t shdr_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.shdr_##fn_name(shdr); \ +} + +#define SHDR_WORD(fn_name) \ +static inline uint32_t shdr64_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.r(&shdr->e64.sh_##fn_name); \ +} \ + \ +static inline uint32_t shdr32_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.r(&shdr->e32.sh_##fn_name); \ +} \ +static inline uint32_t shdr_##fn_name(Elf_Shdr *shdr) \ +{ \ + return elf_parser.shdr_##fn_name(shdr); \ +} + +SHDR_ADDR(addr) +SHDR_ADDR(offset) +SHDR_ADDR(size) +SHDR_ADDR(entsize) + +SHDR_WORD(link) +SHDR_WORD(name) +SHDR_WORD(type) + +#define SYM_ADDR(fn_name) \ +static inline uint64_t sym64_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.r8(&sym->e64.st_##fn_name); \ +} \ + \ +static inline uint64_t sym32_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.r(&sym->e32.st_##fn_name); \ +} \ + \ +static inline uint64_t sym_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.sym_##fn_name(sym); \ +} + +#define SYM_WORD(fn_name) \ +static inline uint32_t sym64_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.r(&sym->e64.st_##fn_name); \ +} \ + \ +static inline uint32_t sym32_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.r(&sym->e32.st_##fn_name); \ +} \ + \ +static inline uint32_t sym_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.sym_##fn_name(sym); \ +} + +#define SYM_HALF(fn_name) \ +static inline uint16_t sym64_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.r2(&sym->e64.st_##fn_name); \ +} \ + \ +static inline uint16_t sym32_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.r2(&sym->e32.st_##fn_name); \ +} \ + \ +static inline uint16_t sym_##fn_name(Elf_Sym *sym) \ +{ \ + return elf_parser.sym_##fn_name(sym); \ +} + +static inline uint8_t sym64_type(Elf_Sym *sym) +{ + return ELF64_ST_TYPE(sym->e64.st_info); +} + +static inline uint8_t sym32_type(Elf_Sym *sym) +{ + return ELF32_ST_TYPE(sym->e32.st_info); +} + +static inline uint8_t sym_type(Elf_Sym *sym) +{ + return elf_parser.sym_type(sym); +} + +SYM_ADDR(value) +SYM_WORD(name) +SYM_HALF(shndx) + +#define __maybe_unused __attribute__((__unused__)) + +#define RELA_ADDR(fn_name) \ +static inline uint64_t rela64_##fn_name(Elf_Rela *rela) \ +{ \ + return elf_parser.r8((uint64_t *)&rela->e64.r_##fn_name); \ +} \ + \ +static inline uint64_t rela32_##fn_name(Elf_Rela *rela) \ +{ \ + return elf_parser.r((uint32_t *)&rela->e32.r_##fn_name); \ +} \ + \ +static inline uint64_t __maybe_unused rela_##fn_name(Elf_Rela *rela) \ +{ \ + return elf_parser.rela_##fn_name(rela); \ +} + +RELA_ADDR(offset) +RELA_ADDR(info) +RELA_ADDR(addend) + +static inline void rela64_write_addend(Elf_Rela *rela, uint64_t val) +{ + elf_parser.w8(val, (uint64_t *)&rela->e64.r_addend); +} + +static inline void rela32_write_addend(Elf_Rela *rela, uint64_t val) +{ + elf_parser.w(val, (uint32_t *)&rela->e32.r_addend); +} + +static inline uint32_t rbe(const uint32_t *x) +{ + return get_unaligned_be32(x); +} + +static inline uint16_t r2be(const uint16_t *x) +{ + return get_unaligned_be16(x); +} + +static inline uint64_t r8be(const uint64_t *x) +{ + return get_unaligned_be64(x); +} + +static inline uint32_t rle(const uint32_t *x) +{ + return get_unaligned_le32(x); +} + +static inline uint16_t r2le(const uint16_t *x) +{ + return get_unaligned_le16(x); +} + +static inline uint64_t r8le(const uint64_t *x) +{ + return get_unaligned_le64(x); +} + +static inline void wbe(uint32_t val, uint32_t *x) +{ + put_unaligned_be32(val, x); +} + +static inline void wle(uint32_t val, uint32_t *x) +{ + put_unaligned_le32(val, x); +} + +static inline void w8be(uint64_t val, uint64_t *x) +{ + put_unaligned_be64(val, x); +} + +static inline void w8le(uint64_t val, uint64_t *x) +{ + put_unaligned_le64(val, x); +} + +void *elf_map(char const *fname, size_t *size, uint32_t types); +void elf_unmap(void *addr, size_t size); +int elf_map_machine(void *addr); +int elf_map_long_size(void *addr); + +#endif /* _SCRIPTS_ELF_PARSE_H */ -- cgit v1.3.1