| /****************************************************************************** |
| * 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 __X86_EMULATE_H__ |
| #define __X86_EMULATE_H__ |
| |
| struct x86_emulate_ctxt; |
| |
| /* |
| * 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 2 /* retry the instruction for some reason */ |
| #define X86EMUL_CMPXCHG_FAILED 2 /* cmpxchg did not see expected value */ |
| struct x86_emulate_ops { |
| /* |
| * read_std: Read bytes of standard (non-emulated/special) memory. |
| * Used for instruction fetch, stack operations, and others. |
| * @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_std)(unsigned long addr, void *val, |
| unsigned int bytes, struct kvm_vcpu *vcpu); |
| |
| /* |
| * write_std: Write bytes of standard (non-emulated/special) memory. |
| * Used for stack operations, and others. |
| * @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_std)(unsigned long addr, const void *val, |
| unsigned int bytes, struct kvm_vcpu *vcpu); |
| |
| /* |
| * 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) (unsigned long addr, |
| void *val, |
| unsigned int bytes, |
| struct kvm_vcpu *vcpu); |
| |
| /* |
| * write_emulated: Read bytes from 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) (unsigned long addr, |
| const void *val, |
| unsigned int bytes, |
| struct kvm_vcpu *vcpu); |
| |
| /* |
| * 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) (unsigned long addr, |
| const void *old, |
| const void *new, |
| unsigned int bytes, |
| struct kvm_vcpu *vcpu); |
| |
| }; |
| |
| /* Type, address-of, and value of an instruction's operand. */ |
| struct operand { |
| enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type; |
| unsigned int bytes; |
| unsigned long val, orig_val, *ptr; |
| }; |
| |
| struct decode_cache { |
| u8 twobyte; |
| u8 b; |
| u8 lock_prefix; |
| u8 rep_prefix; |
| u8 op_bytes; |
| u8 ad_bytes; |
| struct operand src; |
| struct operand dst; |
| unsigned long *override_base; |
| unsigned int d; |
| unsigned long regs[NR_VCPU_REGS]; |
| unsigned long eip; |
| /* modrm */ |
| u8 modrm; |
| u8 modrm_mod; |
| u8 modrm_reg; |
| u8 modrm_rm; |
| u8 use_modrm_ea; |
| unsigned long modrm_ea; |
| unsigned long modrm_val; |
| }; |
| |
| struct x86_emulate_ctxt { |
| /* Register state before/after emulation. */ |
| struct kvm_vcpu *vcpu; |
| |
| /* Linear faulting address (if emulating a page-faulting instruction). */ |
| unsigned long eflags; |
| unsigned long cr2; |
| |
| /* Emulated execution mode, represented by an X86EMUL_MODE value. */ |
| int mode; |
| |
| unsigned long cs_base; |
| unsigned long ds_base; |
| unsigned long es_base; |
| unsigned long ss_base; |
| unsigned long gs_base; |
| unsigned long fs_base; |
| |
| /* decode cache */ |
| |
| struct decode_cache decode; |
| }; |
| |
| /* Execution mode, passed to the emulator. */ |
| #define X86EMUL_MODE_REAL 0 /* Real mode. */ |
| #define X86EMUL_MODE_PROT16 2 /* 16-bit protected mode. */ |
| #define X86EMUL_MODE_PROT32 4 /* 32-bit protected mode. */ |
| #define X86EMUL_MODE_PROT64 8 /* 64-bit (long) mode. */ |
| |
| /* Host execution mode. */ |
| #if defined(__i386__) |
| #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, |
| struct x86_emulate_ops *ops); |
| int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, |
| struct x86_emulate_ops *ops); |
| |
| #endif /* __X86_EMULATE_H__ */ |