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+/* 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 */
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-28 23:04:52 +0000