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Diffstat (limited to 'arch/x86/kvm/kvm_emulate.h')
| -rw-r--r-- | arch/x86/kvm/kvm_emulate.h | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h new file mode 100644 index 000000000000..43c93ffa76ed --- /dev/null +++ b/arch/x86/kvm/kvm_emulate.h @@ -0,0 +1,509 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/****************************************************************************** + * x86_emulate.h + * + * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. + * + * Copyright (c) 2005 Keir Fraser + * + * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 + */ + +#ifndef _ASM_X86_KVM_X86_EMULATE_H +#define _ASM_X86_KVM_X86_EMULATE_H + +#include <asm/desc_defs.h> + +struct x86_emulate_ctxt; +enum x86_intercept; +enum x86_intercept_stage; + +struct x86_exception { + u8 vector; + bool error_code_valid; + u16 error_code; + bool nested_page_fault; + u64 address; /* cr2 or nested page fault gpa */ + u8 async_page_fault; +}; + +/* + * This struct is used to carry enough information from the instruction + * decoder to main KVM so that a decision can be made whether the + * instruction needs to be intercepted or not. + */ +struct x86_instruction_info { + u8 intercept; /* which intercept */ + u8 rep_prefix; /* rep prefix? */ + u8 modrm_mod; /* mod part of modrm */ + u8 modrm_reg; /* index of register used */ + u8 modrm_rm; /* rm part of modrm */ + u64 src_val; /* value of source operand */ + u64 dst_val; /* value of destination operand */ + u8 src_bytes; /* size of source operand */ + u8 dst_bytes; /* size of destination operand */ + u8 ad_bytes; /* size of src/dst address */ + u64 next_rip; /* rip following the instruction */ +}; + +/* + * x86_emulate_ops: + * + * These operations represent the instruction emulator's interface to memory. + * There are two categories of operation: those that act on ordinary memory + * regions (*_std), and those that act on memory regions known to require + * special treatment or emulation (*_emulated). + * + * The emulator assumes that an instruction accesses only one 'emulated memory' + * location, that this location is the given linear faulting address (cr2), and + * that this is one of the instruction's data operands. Instruction fetches and + * stack operations are assumed never to access emulated memory. The emulator + * automatically deduces which operand of a string-move operation is accessing + * emulated memory, and assumes that the other operand accesses normal memory. + * + * NOTES: + * 1. The emulator isn't very smart about emulated vs. standard memory. + * 'Emulated memory' access addresses should be checked for sanity. + * 'Normal memory' accesses may fault, and the caller must arrange to + * detect and handle reentrancy into the emulator via recursive faults. + * Accesses may be unaligned and may cross page boundaries. + * 2. If the access fails (cannot emulate, or a standard access faults) then + * it is up to the memop to propagate the fault to the guest VM via + * some out-of-band mechanism, unknown to the emulator. The memop signals + * failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will + * then immediately bail. + * 3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only + * cmpxchg8b_emulated need support 8-byte accesses. + * 4. The emulator cannot handle 64-bit mode emulation on an x86/32 system. + */ +/* Access completed successfully: continue emulation as normal. */ +#define X86EMUL_CONTINUE 0 +/* Access is unhandleable: bail from emulation and return error to caller. */ +#define X86EMUL_UNHANDLEABLE 1 +/* Terminate emulation but return success to the caller. */ +#define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */ +#define X86EMUL_RETRY_INSTR 3 /* retry the instruction for some reason */ +#define X86EMUL_CMPXCHG_FAILED 4 /* cmpxchg did not see expected value */ +#define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */ +#define X86EMUL_INTERCEPTED 6 /* Intercepted by nested VMCB/VMCS */ + +struct x86_emulate_ops { + /* + * read_gpr: read a general purpose register (rax - r15) + * + * @reg: gpr number. + */ + ulong (*read_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg); + /* + * write_gpr: write a general purpose register (rax - r15) + * + * @reg: gpr number. + * @val: value to write. + */ + void (*write_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val); + /* + * read_std: Read bytes of standard (non-emulated/special) memory. + * Used for descriptor reading. + * @addr: [IN ] Linear address from which to read. + * @val: [OUT] Value read from memory, zero-extended to 'u_long'. + * @bytes: [IN ] Number of bytes to read from memory. + * @system:[IN ] Whether the access is forced to be at CPL0. + */ + int (*read_std)(struct x86_emulate_ctxt *ctxt, + unsigned long addr, void *val, + unsigned int bytes, + struct x86_exception *fault, bool system); + + /* + * read_phys: Read bytes of standard (non-emulated/special) memory. + * Used for descriptor reading. + * @addr: [IN ] Physical address from which to read. + * @val: [OUT] Value read from memory. + * @bytes: [IN ] Number of bytes to read from memory. + */ + int (*read_phys)(struct x86_emulate_ctxt *ctxt, unsigned long addr, + void *val, unsigned int bytes); + + /* + * write_std: Write bytes of standard (non-emulated/special) memory. + * Used for descriptor writing. + * @addr: [IN ] Linear address to which to write. + * @val: [OUT] Value write to memory, zero-extended to 'u_long'. + * @bytes: [IN ] Number of bytes to write to memory. + * @system:[IN ] Whether the access is forced to be at CPL0. + */ + int (*write_std)(struct x86_emulate_ctxt *ctxt, + unsigned long addr, void *val, unsigned int bytes, + struct x86_exception *fault, bool system); + /* + * fetch: Read bytes of standard (non-emulated/special) memory. + * Used for instruction fetch. + * @addr: [IN ] Linear address from which to read. + * @val: [OUT] Value read from memory, zero-extended to 'u_long'. + * @bytes: [IN ] Number of bytes to read from memory. + */ + int (*fetch)(struct x86_emulate_ctxt *ctxt, + unsigned long addr, void *val, unsigned int bytes, + struct x86_exception *fault); + + /* + * read_emulated: Read bytes from emulated/special memory area. + * @addr: [IN ] Linear address from which to read. + * @val: [OUT] Value read from memory, zero-extended to 'u_long'. + * @bytes: [IN ] Number of bytes to read from memory. + */ + int (*read_emulated)(struct x86_emulate_ctxt *ctxt, + unsigned long addr, void *val, unsigned int bytes, + struct x86_exception *fault); + + /* + * write_emulated: Write bytes to emulated/special memory area. + * @addr: [IN ] Linear address to which to write. + * @val: [IN ] Value to write to memory (low-order bytes used as + * required). + * @bytes: [IN ] Number of bytes to write to memory. + */ + int (*write_emulated)(struct x86_emulate_ctxt *ctxt, + unsigned long addr, const void *val, + unsigned int bytes, + struct x86_exception *fault); + + /* + * cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an + * emulated/special memory area. + * @addr: [IN ] Linear address to access. + * @old: [IN ] Value expected to be current at @addr. + * @new: [IN ] Value to write to @addr. + * @bytes: [IN ] Number of bytes to access using CMPXCHG. + */ + int (*cmpxchg_emulated)(struct x86_emulate_ctxt *ctxt, + unsigned long addr, + const void *old, + const void *new, + unsigned int bytes, + struct x86_exception *fault); + void (*invlpg)(struct x86_emulate_ctxt *ctxt, ulong addr); + + int (*pio_in_emulated)(struct x86_emulate_ctxt *ctxt, + int size, unsigned short port, void *val, + unsigned int count); + + int (*pio_out_emulated)(struct x86_emulate_ctxt *ctxt, + int size, unsigned short port, const void *val, + unsigned int count); + + bool (*get_segment)(struct x86_emulate_ctxt *ctxt, u16 *selector, + struct desc_struct *desc, u32 *base3, int seg); + void (*set_segment)(struct x86_emulate_ctxt *ctxt, u16 selector, + struct desc_struct *desc, u32 base3, int seg); + unsigned long (*get_cached_segment_base)(struct x86_emulate_ctxt *ctxt, + int seg); + void (*get_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); + void (*get_idt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); + void (*set_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); + void (*set_idt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); + ulong (*get_cr)(struct x86_emulate_ctxt *ctxt, int cr); + int (*set_cr)(struct x86_emulate_ctxt *ctxt, int cr, ulong val); + int (*cpl)(struct x86_emulate_ctxt *ctxt); + int (*get_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong *dest); + int (*set_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong value); + u64 (*get_smbase)(struct x86_emulate_ctxt *ctxt); + void (*set_smbase)(struct x86_emulate_ctxt *ctxt, u64 smbase); + int (*set_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data); + int (*get_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata); + int (*check_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc); + int (*read_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc, u64 *pdata); + void (*halt)(struct x86_emulate_ctxt *ctxt); + void (*wbinvd)(struct x86_emulate_ctxt *ctxt); + int (*fix_hypercall)(struct x86_emulate_ctxt *ctxt); + int (*intercept)(struct x86_emulate_ctxt *ctxt, + struct x86_instruction_info *info, + enum x86_intercept_stage stage); + + bool (*get_cpuid)(struct x86_emulate_ctxt *ctxt, u32 *eax, u32 *ebx, + u32 *ecx, u32 *edx, bool exact_only); + bool (*guest_has_long_mode)(struct x86_emulate_ctxt *ctxt); + bool (*guest_has_movbe)(struct x86_emulate_ctxt *ctxt); + bool (*guest_has_fxsr)(struct x86_emulate_ctxt *ctxt); + + void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); + + unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt); + void (*set_hflags)(struct x86_emulate_ctxt *ctxt, unsigned hflags); + int (*pre_leave_smm)(struct x86_emulate_ctxt *ctxt, + const char *smstate); + void (*post_leave_smm)(struct x86_emulate_ctxt *ctxt); + int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); +}; + +typedef u32 __attribute__((vector_size(16))) sse128_t; + +/* Type, address-of, and value of an instruction's operand. */ +struct operand { + enum { OP_REG, OP_MEM, OP_MEM_STR, OP_IMM, OP_XMM, OP_MM, OP_NONE } type; + unsigned int bytes; + unsigned int count; + union { + unsigned long orig_val; + u64 orig_val64; + }; + union { + unsigned long *reg; + struct segmented_address { + ulong ea; + unsigned seg; + } mem; + unsigned xmm; + unsigned mm; + } addr; + union { + unsigned long val; + u64 val64; + char valptr[sizeof(sse128_t)]; + sse128_t vec_val; + u64 mm_val; + void *data; + }; +}; + +struct fetch_cache { + u8 data[15]; + u8 *ptr; + u8 *end; +}; + +struct read_cache { + u8 data[1024]; + unsigned long pos; + unsigned long end; +}; + +/* Execution mode, passed to the emulator. */ +enum x86emul_mode { + X86EMUL_MODE_REAL, /* Real mode. */ + X86EMUL_MODE_VM86, /* Virtual 8086 mode. */ + X86EMUL_MODE_PROT16, /* 16-bit protected mode. */ + X86EMUL_MODE_PROT32, /* 32-bit protected mode. */ + X86EMUL_MODE_PROT64, /* 64-bit (long) mode. */ +}; + +/* These match some of the HF_* flags defined in kvm_host.h */ +#define X86EMUL_GUEST_MASK (1 << 5) /* VCPU is in guest-mode */ +#define X86EMUL_SMM_MASK (1 << 6) +#define X86EMUL_SMM_INSIDE_NMI_MASK (1 << 7) + +/* + * fastop functions are declared as taking a never-defined fastop parameter, + * so they can't be called from C directly. + */ +struct fastop; + +typedef void (*fastop_t)(struct fastop *); + +struct x86_emulate_ctxt { + void *vcpu; + const struct x86_emulate_ops *ops; + + /* Register state before/after emulation. */ + unsigned long eflags; + unsigned long eip; /* eip before instruction emulation */ + /* Emulated execution mode, represented by an X86EMUL_MODE value. */ + enum x86emul_mode mode; + + /* interruptibility state, as a result of execution of STI or MOV SS */ + int interruptibility; + + bool perm_ok; /* do not check permissions if true */ + bool ud; /* inject an #UD if host doesn't support insn */ + bool tf; /* TF value before instruction (after for syscall/sysret) */ + + bool have_exception; + struct x86_exception exception; + + /* GPA available */ + bool gpa_available; + gpa_t gpa_val; + + /* + * decode cache + */ + + /* current opcode length in bytes */ + u8 opcode_len; + u8 b; + u8 intercept; + u8 op_bytes; + u8 ad_bytes; + union { + int (*execute)(struct x86_emulate_ctxt *ctxt); + fastop_t fop; + }; + int (*check_perm)(struct x86_emulate_ctxt *ctxt); + /* + * The following six fields are cleared together, + * the rest are initialized unconditionally in x86_decode_insn + * or elsewhere + */ + bool rip_relative; + u8 rex_prefix; + u8 lock_prefix; + u8 rep_prefix; + /* bitmaps of registers in _regs[] that can be read */ + u32 regs_valid; + /* bitmaps of registers in _regs[] that have been written */ + u32 regs_dirty; + /* modrm */ + u8 modrm; + u8 modrm_mod; + u8 modrm_reg; + u8 modrm_rm; + u8 modrm_seg; + u8 seg_override; + u64 d; + unsigned long _eip; + + /* Here begins the usercopy section. */ + struct operand src; + struct operand src2; + struct operand dst; + struct operand memop; + unsigned long _regs[NR_VCPU_REGS]; + struct operand *memopp; + struct fetch_cache fetch; + struct read_cache io_read; + struct read_cache mem_read; +}; + +/* Repeat String Operation Prefix */ +#define REPE_PREFIX 0xf3 +#define REPNE_PREFIX 0xf2 + +/* CPUID vendors */ +#define X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx 0x68747541 +#define X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx 0x444d4163 +#define X86EMUL_CPUID_VENDOR_AuthenticAMD_edx 0x69746e65 + +#define X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx 0x69444d41 +#define X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx 0x21726574 +#define X86EMUL_CPUID_VENDOR_AMDisbetterI_edx 0x74656273 + +#define X86EMUL_CPUID_VENDOR_HygonGenuine_ebx 0x6f677948 +#define X86EMUL_CPUID_VENDOR_HygonGenuine_ecx 0x656e6975 +#define X86EMUL_CPUID_VENDOR_HygonGenuine_edx 0x6e65476e + +#define X86EMUL_CPUID_VENDOR_GenuineIntel_ebx 0x756e6547 +#define X86EMUL_CPUID_VENDOR_GenuineIntel_ecx 0x6c65746e +#define X86EMUL_CPUID_VENDOR_GenuineIntel_edx 0x49656e69 + +#define X86EMUL_CPUID_VENDOR_CentaurHauls_ebx 0x746e6543 +#define X86EMUL_CPUID_VENDOR_CentaurHauls_ecx 0x736c7561 +#define X86EMUL_CPUID_VENDOR_CentaurHauls_edx 0x48727561 + +static inline bool is_guest_vendor_intel(u32 ebx, u32 ecx, u32 edx) +{ + return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && + ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && + edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx; +} + +static inline bool is_guest_vendor_amd(u32 ebx, u32 ecx, u32 edx) +{ + return (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx && + ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx && + edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx) || + (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx && + ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx && + edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx); +} + +static inline bool is_guest_vendor_hygon(u32 ebx, u32 ecx, u32 edx) +{ + return ebx == X86EMUL_CPUID_VENDOR_HygonGenuine_ebx && + ecx == X86EMUL_CPUID_VENDOR_HygonGenuine_ecx && + edx == X86EMUL_CPUID_VENDOR_HygonGenuine_edx; +} + +enum x86_intercept_stage { + X86_ICTP_NONE = 0, /* Allow zero-init to not match anything */ + X86_ICPT_PRE_EXCEPT, + X86_ICPT_POST_EXCEPT, + X86_ICPT_POST_MEMACCESS, +}; + +enum x86_intercept { + x86_intercept_none, + x86_intercept_cr_read, + x86_intercept_cr_write, + x86_intercept_clts, + x86_intercept_lmsw, + x86_intercept_smsw, + x86_intercept_dr_read, + x86_intercept_dr_write, + x86_intercept_lidt, + x86_intercept_sidt, + x86_intercept_lgdt, + x86_intercept_sgdt, + x86_intercept_lldt, + x86_intercept_sldt, + x86_intercept_ltr, + x86_intercept_str, + x86_intercept_rdtsc, + x86_intercept_rdpmc, + x86_intercept_pushf, + x86_intercept_popf, + x86_intercept_cpuid, + x86_intercept_rsm, + x86_intercept_iret, + x86_intercept_intn, + x86_intercept_invd, + x86_intercept_pause, + x86_intercept_hlt, + x86_intercept_invlpg, + x86_intercept_invlpga, + x86_intercept_vmrun, + x86_intercept_vmload, + x86_intercept_vmsave, + x86_intercept_vmmcall, + x86_intercept_stgi, + x86_intercept_clgi, + x86_intercept_skinit, + x86_intercept_rdtscp, + x86_intercept_icebp, + x86_intercept_wbinvd, + x86_intercept_monitor, + x86_intercept_mwait, + x86_intercept_rdmsr, + x86_intercept_wrmsr, + x86_intercept_in, + x86_intercept_ins, + x86_intercept_out, + x86_intercept_outs, + x86_intercept_xsetbv, + + nr_x86_intercepts +}; + +/* Host execution mode. */ +#if defined(CONFIG_X86_32) +#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32 +#elif defined(CONFIG_X86_64) +#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64 +#endif + +int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len); +bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt); +#define EMULATION_FAILED -1 +#define EMULATION_OK 0 +#define EMULATION_RESTART 1 +#define EMULATION_INTERCEPTED 2 +void init_decode_cache(struct x86_emulate_ctxt *ctxt); +int x86_emulate_insn(struct x86_emulate_ctxt *ctxt); +int emulator_task_switch(struct x86_emulate_ctxt *ctxt, + u16 tss_selector, int idt_index, int reason, + bool has_error_code, u32 error_code); +int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq); +void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt); +void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt); +bool emulator_can_use_gpa(struct x86_emulate_ctxt *ctxt); + +#endif /* _ASM_X86_KVM_X86_EMULATE_H */ |