186 строки
7.0 KiB
C
186 строки
7.0 KiB
C
/******************************************************************************
|
|
* 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,
|
|
unsigned long *val,
|
|
unsigned int bytes, struct x86_emulate_ctxt * ctxt);
|
|
|
|
/*
|
|
* 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,
|
|
unsigned long val,
|
|
unsigned int bytes, struct x86_emulate_ctxt * ctxt);
|
|
|
|
/*
|
|
* 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,
|
|
unsigned long *val,
|
|
unsigned int bytes,
|
|
struct x86_emulate_ctxt * ctxt);
|
|
|
|
/*
|
|
* 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,
|
|
unsigned long val,
|
|
unsigned int bytes,
|
|
struct x86_emulate_ctxt * ctxt);
|
|
|
|
/*
|
|
* 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,
|
|
unsigned long old,
|
|
unsigned long new,
|
|
unsigned int bytes,
|
|
struct x86_emulate_ctxt * ctxt);
|
|
|
|
/*
|
|
* cmpxchg8b_emulated: Emulate an atomic (LOCKed) CMPXCHG8B 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.
|
|
* NOTES:
|
|
* 1. This function is only ever called when emulating a real CMPXCHG8B.
|
|
* 2. This function is *never* called on x86/64 systems.
|
|
* 2. Not defining this function (i.e., specifying NULL) is equivalent
|
|
* to defining a function that always returns X86EMUL_UNHANDLEABLE.
|
|
*/
|
|
int (*cmpxchg8b_emulated) (unsigned long addr,
|
|
unsigned long old_lo,
|
|
unsigned long old_hi,
|
|
unsigned long new_lo,
|
|
unsigned long new_hi,
|
|
struct x86_emulate_ctxt * ctxt);
|
|
};
|
|
|
|
struct cpu_user_regs;
|
|
|
|
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;
|
|
};
|
|
|
|
/* 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
|
|
|
|
/*
|
|
* x86_emulate_memop: Emulate an instruction that faulted attempting to
|
|
* read/write a 'special' memory area.
|
|
* Returns -1 on failure, 0 on success.
|
|
*/
|
|
int x86_emulate_memop(struct x86_emulate_ctxt *ctxt,
|
|
struct x86_emulate_ops *ops);
|
|
|
|
/*
|
|
* Given the 'reg' portion of a ModRM byte, and a register block, return a
|
|
* pointer into the block that addresses the relevant register.
|
|
* @highbyte_regs specifies whether to decode AH,CH,DH,BH.
|
|
*/
|
|
void *decode_register(u8 modrm_reg, unsigned long *regs,
|
|
int highbyte_regs);
|
|
|
|
#endif /* __X86_EMULATE_H__ */
|