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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 21:00:03 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-10 21:00:03 +0300 |
commit | 2e97a0c02b94f2ecd5cbf29ded90c5db055e8ad0 (patch) | |
tree | 3849e2b60cc86ae948a42f31368015685305566f | |
parent | 4a692ae360615026b25d64c29fc7c12c0ef63c5f (diff) | |
parent | 4d5cff69fbddbbefef2903faa48263cc5d3ca382 (diff) | |
download | linux-2e97a0c02b94f2ecd5cbf29ded90c5db055e8ad0.tar.xz |
Merge tag 'x86_misc_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull misc x86 updates from Borislav Petkov:
"The pile which we cannot find the proper topic for so we stick it in
x86/misc:
- Add support for decoding instructions which do MMIO accesses in
order to use it in SEV and TDX guests
- An include fix and reorg to allow for removing set_fs in UML later"
* tag 'x86_misc_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mtrr: Remove the mtrr_bp_init() stub
x86/sev-es: Use insn_decode_mmio() for MMIO implementation
x86/insn-eval: Introduce insn_decode_mmio()
x86/insn-eval: Introduce insn_get_modrm_reg_ptr()
x86/insn-eval: Handle insn_get_opcode() failure
-rw-r--r-- | arch/x86/include/asm/insn-eval.h | 13 | ||||
-rw-r--r-- | arch/x86/include/asm/mtrr.h | 8 | ||||
-rw-r--r-- | arch/x86/kernel/setup.c | 7 | ||||
-rw-r--r-- | arch/x86/kernel/sev.c | 172 | ||||
-rw-r--r-- | arch/x86/kvm/mmu/spte.c | 1 | ||||
-rw-r--r-- | arch/x86/lib/insn-eval.c | 109 |
6 files changed, 169 insertions, 141 deletions
diff --git a/arch/x86/include/asm/insn-eval.h b/arch/x86/include/asm/insn-eval.h index 4ec3613551e3..43785ee363f1 100644 --- a/arch/x86/include/asm/insn-eval.h +++ b/arch/x86/include/asm/insn-eval.h @@ -19,6 +19,7 @@ bool insn_has_rep_prefix(struct insn *insn); void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs); int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs); int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs); +unsigned long *insn_get_modrm_reg_ptr(struct insn *insn, struct pt_regs *regs); unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx); int insn_get_code_seg_params(struct pt_regs *regs); int insn_get_effective_ip(struct pt_regs *regs, unsigned long *ip); @@ -29,4 +30,16 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs, unsigned char buf[MAX_INSN_SIZE], int buf_size); +enum mmio_type { + MMIO_DECODE_FAILED, + MMIO_WRITE, + MMIO_WRITE_IMM, + MMIO_READ, + MMIO_READ_ZERO_EXTEND, + MMIO_READ_SIGN_EXTEND, + MMIO_MOVS, +}; + +enum mmio_type insn_decode_mmio(struct insn *insn, int *bytes); + #endif /* _ASM_X86_INSN_EVAL_H */ diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h index 829df26fd7a3..76d726074c16 100644 --- a/arch/x86/include/asm/mtrr.h +++ b/arch/x86/include/asm/mtrr.h @@ -24,8 +24,8 @@ #define _ASM_X86_MTRR_H #include <uapi/asm/mtrr.h> -#include <asm/memtype.h> +void mtrr_bp_init(void); /* * The following functions are for use by other drivers that cannot use @@ -43,7 +43,6 @@ extern int mtrr_del(int reg, unsigned long base, unsigned long size); extern int mtrr_del_page(int reg, unsigned long base, unsigned long size); extern void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi); extern void mtrr_ap_init(void); -extern void mtrr_bp_init(void); extern void set_mtrr_aps_delayed_init(void); extern void mtrr_aps_init(void); extern void mtrr_bp_restore(void); @@ -84,11 +83,6 @@ static inline int mtrr_trim_uncached_memory(unsigned long end_pfn) static inline void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi) { } -static inline void mtrr_bp_init(void) -{ - pat_disable("PAT support disabled because CONFIG_MTRR is disabled in the kernel."); -} - #define mtrr_ap_init() do {} while (0) #define set_mtrr_aps_delayed_init() do {} while (0) #define mtrr_aps_init() do {} while (0) diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index e04f5e6eb33f..f7a132eb794d 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -40,6 +40,7 @@ #include <asm/kasan.h> #include <asm/kaslr.h> #include <asm/mce.h> +#include <asm/memtype.h> #include <asm/mtrr.h> #include <asm/realmode.h> #include <asm/olpc_ofw.h> @@ -967,7 +968,11 @@ void __init setup_arch(char **cmdline_p) max_pfn = e820__end_of_ram_pfn(); /* update e820 for memory not covered by WB MTRRs */ - mtrr_bp_init(); + if (IS_ENABLED(CONFIG_MTRR)) + mtrr_bp_init(); + else + pat_disable("PAT support disabled because CONFIG_MTRR is disabled in the kernel."); + if (mtrr_trim_uncached_memory(max_pfn)) max_pfn = e820__end_of_ram_pfn(); diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c index c9482f472ab6..e6d316a01fdd 100644 --- a/arch/x86/kernel/sev.c +++ b/arch/x86/kernel/sev.c @@ -792,22 +792,6 @@ static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt) do_early_exception(ctxt->regs, trapnr); } -static long *vc_insn_get_reg(struct es_em_ctxt *ctxt) -{ - long *reg_array; - int offset; - - reg_array = (long *)ctxt->regs; - offset = insn_get_modrm_reg_off(&ctxt->insn, ctxt->regs); - - if (offset < 0) - return NULL; - - offset /= sizeof(long); - - return reg_array + offset; -} - static long *vc_insn_get_rm(struct es_em_ctxt *ctxt) { long *reg_array; @@ -855,76 +839,6 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt, return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2); } -static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb, - struct es_em_ctxt *ctxt) -{ - struct insn *insn = &ctxt->insn; - unsigned int bytes = 0; - enum es_result ret; - int sign_byte; - long *reg_data; - - switch (insn->opcode.bytes[1]) { - /* MMIO Read w/ zero-extension */ - case 0xb6: - bytes = 1; - fallthrough; - case 0xb7: - if (!bytes) - bytes = 2; - - ret = vc_do_mmio(ghcb, ctxt, bytes, true); - if (ret) - break; - - /* Zero extend based on operand size */ - reg_data = vc_insn_get_reg(ctxt); - if (!reg_data) - return ES_DECODE_FAILED; - - memset(reg_data, 0, insn->opnd_bytes); - - memcpy(reg_data, ghcb->shared_buffer, bytes); - break; - - /* MMIO Read w/ sign-extension */ - case 0xbe: - bytes = 1; - fallthrough; - case 0xbf: - if (!bytes) - bytes = 2; - - ret = vc_do_mmio(ghcb, ctxt, bytes, true); - if (ret) - break; - - /* Sign extend based on operand size */ - reg_data = vc_insn_get_reg(ctxt); - if (!reg_data) - return ES_DECODE_FAILED; - - if (bytes == 1) { - u8 *val = (u8 *)ghcb->shared_buffer; - - sign_byte = (*val & 0x80) ? 0xff : 0x00; - } else { - u16 *val = (u16 *)ghcb->shared_buffer; - - sign_byte = (*val & 0x8000) ? 0xff : 0x00; - } - memset(reg_data, sign_byte, insn->opnd_bytes); - - memcpy(reg_data, ghcb->shared_buffer, bytes); - break; - - default: - ret = ES_UNSUPPORTED; - } - - return ret; -} - /* * The MOVS instruction has two memory operands, which raises the * problem that it is not known whether the access to the source or the @@ -992,83 +906,79 @@ static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt, return ES_RETRY; } -static enum es_result vc_handle_mmio(struct ghcb *ghcb, - struct es_em_ctxt *ctxt) +static enum es_result vc_handle_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt) { struct insn *insn = &ctxt->insn; unsigned int bytes = 0; + enum mmio_type mmio; enum es_result ret; + u8 sign_byte; long *reg_data; - switch (insn->opcode.bytes[0]) { - /* MMIO Write */ - case 0x88: - bytes = 1; - fallthrough; - case 0x89: - if (!bytes) - bytes = insn->opnd_bytes; + mmio = insn_decode_mmio(insn, &bytes); + if (mmio == MMIO_DECODE_FAILED) + return ES_DECODE_FAILED; - reg_data = vc_insn_get_reg(ctxt); + if (mmio != MMIO_WRITE_IMM && mmio != MMIO_MOVS) { + reg_data = insn_get_modrm_reg_ptr(insn, ctxt->regs); if (!reg_data) return ES_DECODE_FAILED; + } + switch (mmio) { + case MMIO_WRITE: memcpy(ghcb->shared_buffer, reg_data, bytes); - ret = vc_do_mmio(ghcb, ctxt, bytes, false); break; - - case 0xc6: - bytes = 1; - fallthrough; - case 0xc7: - if (!bytes) - bytes = insn->opnd_bytes; - + case MMIO_WRITE_IMM: memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes); - ret = vc_do_mmio(ghcb, ctxt, bytes, false); break; - - /* MMIO Read */ - case 0x8a: - bytes = 1; - fallthrough; - case 0x8b: - if (!bytes) - bytes = insn->opnd_bytes; - + case MMIO_READ: ret = vc_do_mmio(ghcb, ctxt, bytes, true); if (ret) break; - reg_data = vc_insn_get_reg(ctxt); - if (!reg_data) - return ES_DECODE_FAILED; - /* Zero-extend for 32-bit operation */ if (bytes == 4) *reg_data = 0; memcpy(reg_data, ghcb->shared_buffer, bytes); break; + case MMIO_READ_ZERO_EXTEND: + ret = vc_do_mmio(ghcb, ctxt, bytes, true); + if (ret) + break; + + /* Zero extend based on operand size */ + memset(reg_data, 0, insn->opnd_bytes); + memcpy(reg_data, ghcb->shared_buffer, bytes); + break; + case MMIO_READ_SIGN_EXTEND: + ret = vc_do_mmio(ghcb, ctxt, bytes, true); + if (ret) + break; - /* MOVS instruction */ - case 0xa4: - bytes = 1; - fallthrough; - case 0xa5: - if (!bytes) - bytes = insn->opnd_bytes; + if (bytes == 1) { + u8 *val = (u8 *)ghcb->shared_buffer; - ret = vc_handle_mmio_movs(ctxt, bytes); + sign_byte = (*val & 0x80) ? 0xff : 0x00; + } else { + u16 *val = (u16 *)ghcb->shared_buffer; + + sign_byte = (*val & 0x8000) ? 0xff : 0x00; + } + + /* Sign extend based on operand size */ + memset(reg_data, sign_byte, insn->opnd_bytes); + memcpy(reg_data, ghcb->shared_buffer, bytes); break; - /* Two-Byte Opcodes */ - case 0x0f: - ret = vc_handle_mmio_twobyte_ops(ghcb, ctxt); + case MMIO_MOVS: + ret = vc_handle_mmio_movs(ctxt, bytes); break; default: ret = ES_UNSUPPORTED; + break; } return ret; diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 0c76c45fdb68..fad546df0bba 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -16,6 +16,7 @@ #include "spte.h" #include <asm/e820/api.h> +#include <asm/memtype.h> #include <asm/vmx.h> static bool __read_mostly enable_mmio_caching = true; diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index eb3ccffb9b9d..53e57ef5925c 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -37,8 +37,6 @@ enum reg_type { */ static bool is_string_insn(struct insn *insn) { - insn_get_opcode(insn); - /* All string instructions have a 1-byte opcode. */ if (insn->opcode.nbytes != 1) return false; @@ -851,6 +849,26 @@ int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs) } /** + * insn_get_modrm_reg_ptr() - Obtain register pointer based on ModRM byte + * @insn: Instruction containing the ModRM byte + * @regs: Register values as seen when entering kernel mode + * + * Returns: + * + * The register indicated by the reg part of the ModRM byte. + * The register is obtained as a pointer within pt_regs. + */ +unsigned long *insn_get_modrm_reg_ptr(struct insn *insn, struct pt_regs *regs) +{ + int offset; + + offset = insn_get_modrm_reg_off(insn, regs); + if (offset < 0) + return NULL; + return (void *)regs + offset; +} + +/** * get_seg_base_limit() - obtain base address and limit of a segment * @insn: Instruction. Must be valid. * @regs: Register values as seen when entering kernel mode @@ -1405,6 +1423,9 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs) if (!insn || !regs) return (void __user *)-1L; + if (insn_get_opcode(insn)) + return (void __user *)-1L; + switch (insn->addr_bytes) { case 2: return get_addr_ref_16(insn, regs); @@ -1539,3 +1560,87 @@ bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs, return true; } + +/** + * insn_decode_mmio() - Decode a MMIO instruction + * @insn: Structure to store decoded instruction + * @bytes: Returns size of memory operand + * + * Decodes instruction that used for Memory-mapped I/O. + * + * Returns: + * + * Type of the instruction. Size of the memory operand is stored in + * @bytes. If decode failed, MMIO_DECODE_FAILED returned. + */ +enum mmio_type insn_decode_mmio(struct insn *insn, int *bytes) +{ + enum mmio_type type = MMIO_DECODE_FAILED; + + *bytes = 0; + + if (insn_get_opcode(insn)) + return MMIO_DECODE_FAILED; + + switch (insn->opcode.bytes[0]) { + case 0x88: /* MOV m8,r8 */ + *bytes = 1; + fallthrough; + case 0x89: /* MOV m16/m32/m64, r16/m32/m64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_WRITE; + break; + + case 0xc6: /* MOV m8, imm8 */ + *bytes = 1; + fallthrough; + case 0xc7: /* MOV m16/m32/m64, imm16/imm32/imm64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_WRITE_IMM; + break; + + case 0x8a: /* MOV r8, m8 */ + *bytes = 1; + fallthrough; + case 0x8b: /* MOV r16/r32/r64, m16/m32/m64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_READ; + break; + + case 0xa4: /* MOVS m8, m8 */ + *bytes = 1; + fallthrough; + case 0xa5: /* MOVS m16/m32/m64, m16/m32/m64 */ + if (!*bytes) + *bytes = insn->opnd_bytes; + type = MMIO_MOVS; + break; + + case 0x0f: /* Two-byte instruction */ + switch (insn->opcode.bytes[1]) { + case 0xb6: /* MOVZX r16/r32/r64, m8 */ + *bytes = 1; + fallthrough; + case 0xb7: /* MOVZX r32/r64, m16 */ + if (!*bytes) + *bytes = 2; + type = MMIO_READ_ZERO_EXTEND; + break; + + case 0xbe: /* MOVSX r16/r32/r64, m8 */ + *bytes = 1; + fallthrough; + case 0xbf: /* MOVSX r32/r64, m16 */ + if (!*bytes) + *bytes = 2; + type = MMIO_READ_SIGN_EXTEND; + break; + } + break; + } + + return type; +} |