[deliverable/linux.git] / drivers / kvm / x86_emulate.h

/******************************************************************************
 * 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__ */
Commit	Line	Data
6aa8b732 AK	1	/******************************************************************************
	2	* x86_emulate.h
	3	*
	4	* Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
	5	*
	6	* Copyright (c) 2005 Keir Fraser
	7	*
	8	* From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
	9	*/
	10
	11	#ifndef __X86_EMULATE_H__
	12	#define __X86_EMULATE_H__
	13
	14	struct x86_emulate_ctxt;
	15
	16	/*
	17	* x86_emulate_ops:
	18	*
	19	* These operations represent the instruction emulator's interface to memory.
	20	* There are two categories of operation: those that act on ordinary memory
	21	* regions (*_std), and those that act on memory regions known to require
	22	* special treatment or emulation (*_emulated).
	23	*
	24	* The emulator assumes that an instruction accesses only one 'emulated memory'
	25	* location, that this location is the given linear faulting address (cr2), and
	26	* that this is one of the instruction's data operands. Instruction fetches and
	27	* stack operations are assumed never to access emulated memory. The emulator
	28	* automatically deduces which operand of a string-move operation is accessing
	29	* emulated memory, and assumes that the other operand accesses normal memory.
	30	*
	31	* NOTES:
	32	* 1. The emulator isn't very smart about emulated vs. standard memory.
	33	* 'Emulated memory' access addresses should be checked for sanity.
	34	* 'Normal memory' accesses may fault, and the caller must arrange to
	35	* detect and handle reentrancy into the emulator via recursive faults.
	36	* Accesses may be unaligned and may cross page boundaries.
	37	* 2. If the access fails (cannot emulate, or a standard access faults) then
	38	* it is up to the memop to propagate the fault to the guest VM via
	39	* some out-of-band mechanism, unknown to the emulator. The memop signals
	40	* failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will
	41	* then immediately bail.
	42	* 3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only
	43	* cmpxchg8b_emulated need support 8-byte accesses.
	44	* 4. The emulator cannot handle 64-bit mode emulation on an x86/32 system.
	45	*/
	46	/* Access completed successfully: continue emulation as normal. */
	47	#define X86EMUL_CONTINUE 0
	48	/* Access is unhandleable: bail from emulation and return error to caller. */
	49	#define X86EMUL_UNHANDLEABLE 1
	50	/* Terminate emulation but return success to the caller. */
	51	#define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */
	52	#define X86EMUL_RETRY_INSTR 2 /* retry the instruction for some reason */
	53	#define X86EMUL_CMPXCHG_FAILED 2 /* cmpxchg did not see expected value */
	54	struct x86_emulate_ops {
	55	/*
	56	* read_std: Read bytes of standard (non-emulated/special) memory.
	57	* Used for instruction fetch, stack operations, and others.
	58	* @addr: [IN ] Linear address from which to read.
	59	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	60	* @bytes: [IN ] Number of bytes to read from memory.
	61	*/
4c690a1e	62	int (read_std)(unsigned long addr, void val,
cebff02b	63	unsigned int bytes, struct kvm_vcpu *vcpu);
6aa8b732 AK	64
	65	/*
	66	* write_std: Write bytes of standard (non-emulated/special) memory.
	67	* Used for stack operations, and others.
	68	* @addr: [IN ] Linear address to which to write.
	69	* @val: [IN ] Value to write to memory (low-order bytes used as
	70	* required).
	71	* @bytes: [IN ] Number of bytes to write to memory.
	72	*/
4c690a1e	73	int (write_std)(unsigned long addr, const void val,
cebff02b	74	unsigned int bytes, struct kvm_vcpu *vcpu);
6aa8b732 AK	75
	76	/*
	77	* read_emulated: Read bytes from emulated/special memory area.
	78	* @addr: [IN ] Linear address from which to read.
	79	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	80	* @bytes: [IN ] Number of bytes to read from memory.
	81	*/
	82	int (*read_emulated) (unsigned long addr,
4c690a1e	83	void *val,
6aa8b732	84	unsigned int bytes,
cebff02b	85	struct kvm_vcpu *vcpu);
6aa8b732 AK	86
	87	/*
	88	* write_emulated: Read bytes from emulated/special memory area.
	89	* @addr: [IN ] Linear address to which to write.
	90	* @val: [IN ] Value to write to memory (low-order bytes used as
	91	* required).
	92	* @bytes: [IN ] Number of bytes to write to memory.
	93	*/
	94	int (*write_emulated) (unsigned long addr,
4c690a1e	95	const void *val,
6aa8b732	96	unsigned int bytes,
cebff02b	97	struct kvm_vcpu *vcpu);
6aa8b732 AK	98
	99	/*
	100	* cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an
	101	* emulated/special memory area.
	102	* @addr: [IN ] Linear address to access.
	103	* @old: [IN ] Value expected to be current at @addr.
	104	* @new: [IN ] Value to write to @addr.
	105	* @bytes: [IN ] Number of bytes to access using CMPXCHG.
	106	*/
	107	int (*cmpxchg_emulated) (unsigned long addr,
4c690a1e AK	108	const void *old,
4c690a1e AK	109	const void *new,
6aa8b732	110	unsigned int bytes,
cebff02b	111	struct kvm_vcpu *vcpu);
6aa8b732	112
6aa8b732 AK	113	};
6aa8b732 AK	114
e4e03ded LV	115	/* Type, address-of, and value of an instruction's operand. */
e4e03ded LV	116	struct operand {
a01af5ec	117	enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type;
e4e03ded LV	118	unsigned int bytes;
	119	unsigned long val, orig_val, *ptr;
	120	};
	121
	122	struct decode_cache {
	123	u8 twobyte;
	124	u8 b;
	125	u8 lock_prefix;
	126	u8 rep_prefix;
	127	u8 op_bytes;
	128	u8 ad_bytes;
	129	struct operand src;
	130	struct operand dst;
	131	unsigned long *override_base;
	132	unsigned int d;
	133	unsigned long regs[NR_VCPU_REGS];
	134	unsigned long eip;
	135	/* modrm */
	136	u8 modrm;
	137	u8 modrm_mod;
	138	u8 modrm_reg;
	139	u8 modrm_rm;
	140	u8 use_modrm_ea;
	141	unsigned long modrm_ea;
	142	unsigned long modrm_val;
	143	};
	144
6aa8b732 AK	145	struct x86_emulate_ctxt {
	146	/* Register state before/after emulation. */
	147	struct kvm_vcpu *vcpu;
	148
	149	/* Linear faulting address (if emulating a page-faulting instruction). */
	150	unsigned long eflags;
	151	unsigned long cr2;
	152
	153	/* Emulated execution mode, represented by an X86EMUL_MODE value. */
	154	int mode;
	155
	156	unsigned long cs_base;
	157	unsigned long ds_base;
	158	unsigned long es_base;
	159	unsigned long ss_base;
	160	unsigned long gs_base;
	161	unsigned long fs_base;
e4e03ded LV	162
	163	/* decode cache */
	164
	165	struct decode_cache decode;
6aa8b732 AK	166	};
	167
	168	/* Execution mode, passed to the emulator. */
	169	#define X86EMUL_MODE_REAL 0 /* Real mode. */
	170	#define X86EMUL_MODE_PROT16 2 /* 16-bit protected mode. */
	171	#define X86EMUL_MODE_PROT32 4 /* 32-bit protected mode. */
	172	#define X86EMUL_MODE_PROT64 8 /* 64-bit (long) mode. */
	173
	174	/* Host execution mode. */
	175	#if defined(__i386__)
	176	#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32
05b3e0c2	177	#elif defined(CONFIG_X86_64)
6aa8b732 AK	178	#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64
	179	#endif
	180
1be3aa47 LV	181	int x86_decode_insn(struct x86_emulate_ctxt *ctxt,
	182	struct x86_emulate_ops *ops);
	183	int x86_emulate_insn(struct x86_emulate_ctxt *ctxt,
	184	struct x86_emulate_ops *ops);
6aa8b732	185
6aa8b732	186	#endif /* __X86_EMULATE_H__ */