[net-next-2.6.git] / arch / x86 / include / asm / kvm_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 _ASM_X86_KVM_X86_EMULATE_H
#define _ASM_X86_KVM_X86_EMULATE_H

#include <asm/desc_defs.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     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 */

struct x86_emulate_ops {
	/*
	 * 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.
	 */
	int (*read_std)(unsigned long addr, void *val,
			unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error);

	/*
	 * 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.
	 */
	int (*write_std)(unsigned long addr, void *val,
			 unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error);
	/*
	 * 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)(unsigned long addr, void *val,
			unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error);

	/*
	 * 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,
			     unsigned int *error,
			     struct kvm_vcpu *vcpu);

	/*
	 * 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)(unsigned long addr,
			      const void *val,
			      unsigned int bytes,
			      unsigned int *error,
			      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,
				unsigned int *error,
				struct kvm_vcpu *vcpu);

	int (*pio_in_emulated)(int size, unsigned short port, void *val,
			       unsigned int count, struct kvm_vcpu *vcpu);

	int (*pio_out_emulated)(int size, unsigned short port, const void *val,
				unsigned int count, struct kvm_vcpu *vcpu);

	bool (*get_cached_descriptor)(struct desc_struct *desc,
				      int seg, struct kvm_vcpu *vcpu);
	void (*set_cached_descriptor)(struct desc_struct *desc,
				      int seg, struct kvm_vcpu *vcpu);
	u16 (*get_segment_selector)(int seg, struct kvm_vcpu *vcpu);
	void (*set_segment_selector)(u16 sel, int seg, struct kvm_vcpu *vcpu);
	unsigned long (*get_cached_segment_base)(int seg, struct kvm_vcpu *vcpu);
	void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu);
	ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu);
	int (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu);
	int (*cpl)(struct kvm_vcpu *vcpu);
	int (*get_dr)(int dr, unsigned long *dest, struct kvm_vcpu *vcpu);
	int (*set_dr)(int dr, unsigned long value, struct kvm_vcpu *vcpu);
	int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
	int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
};

/* 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;
	union {
		unsigned long orig_val;
		u64 orig_val64;
	};
	unsigned long *ptr;
	union {
		unsigned long val;
		u64 val64;
		char valptr[sizeof(unsigned long) + 2];
	};
};

struct fetch_cache {
	u8 data[15];
	unsigned long start;
	unsigned long end;
};

struct read_cache {
	u8 data[1024];
	unsigned long pos;
	unsigned long end;
};

struct decode_cache {
	u8 twobyte;
	u8 b;
	u8 lock_prefix;
	u8 rep_prefix;
	u8 op_bytes;
	u8 ad_bytes;
	u8 rex_prefix;
	struct operand src;
	struct operand src2;
	struct operand dst;
	bool has_seg_override;
	u8 seg_override;
	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;
	bool rip_relative;
	unsigned long modrm_ea;
	void *modrm_ptr;
	unsigned long modrm_val;
	struct fetch_cache fetch;
	struct read_cache io_read;
	struct read_cache mem_read;
};

struct x86_emulate_ctxt {
	/* Register state before/after emulation. */
	struct kvm_vcpu *vcpu;

	unsigned long eflags;
	unsigned long eip; /* eip before instruction emulation */
	/* Emulated execution mode, represented by an X86EMUL_MODE value. */
	int mode;
	u32 cs_base;

	/* interruptibility state, as a result of execution of STI or MOV SS */
	int interruptibility;

	bool restart; /* restart string instruction after writeback */

	int exception; /* exception that happens during emulation or -1 */
	u32 error_code; /* error code for exception */
	bool error_code_valid;
	unsigned long cr2; /* faulted address in case of #PF */

	/* decode cache */
	struct decode_cache decode;
};

/* Repeat String Operation Prefix */
#define REPE_PREFIX	1
#define REPNE_PREFIX	2

/* Execution mode, passed to the emulator. */
#define X86EMUL_MODE_REAL     0	/* Real mode.             */
#define X86EMUL_MODE_VM86     1	/* Virtual 8086 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(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,
		    struct x86_emulate_ops *ops);
int x86_emulate_insn(struct x86_emulate_ctxt *ctxt,
		     struct x86_emulate_ops *ops);
int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
			 struct x86_emulate_ops *ops,
			 u16 tss_selector, int reason,
			 bool has_error_code, u32 error_code);

#endif /* _ASM_X86_KVM_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
1965aae3 PA	11	#ifndef _ASM_X86_KVM_X86_EMULATE_H
1965aae3 PA	12	#define _ASM_X86_KVM_X86_EMULATE_H
6aa8b732	13
38ba30ba GN	14	#include <asm/desc_defs.h>
38ba30ba GN	15
6aa8b732 AK	16	struct x86_emulate_ctxt;
	17
	18	/*
	19	* x86_emulate_ops:
	20	*
	21	* These operations represent the instruction emulator's interface to memory.
	22	* There are two categories of operation: those that act on ordinary memory
	23	* regions (*_std), and those that act on memory regions known to require
	24	* special treatment or emulation (*_emulated).
	25	*
	26	* The emulator assumes that an instruction accesses only one 'emulated memory'
	27	* location, that this location is the given linear faulting address (cr2), and
	28	* that this is one of the instruction's data operands. Instruction fetches and
	29	* stack operations are assumed never to access emulated memory. The emulator
	30	* automatically deduces which operand of a string-move operation is accessing
	31	* emulated memory, and assumes that the other operand accesses normal memory.
	32	*
	33	* NOTES:
	34	* 1. The emulator isn't very smart about emulated vs. standard memory.
	35	* 'Emulated memory' access addresses should be checked for sanity.
	36	* 'Normal memory' accesses may fault, and the caller must arrange to
	37	* detect and handle reentrancy into the emulator via recursive faults.
	38	* Accesses may be unaligned and may cross page boundaries.
	39	* 2. If the access fails (cannot emulate, or a standard access faults) then
	40	* it is up to the memop to propagate the fault to the guest VM via
	41	* some out-of-band mechanism, unknown to the emulator. The memop signals
	42	* failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will
	43	* then immediately bail.
	44	* 3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only
	45	* cmpxchg8b_emulated need support 8-byte accesses.
	46	* 4. The emulator cannot handle 64-bit mode emulation on an x86/32 system.
	47	*/
	48	/* Access completed successfully: continue emulation as normal. */
	49	#define X86EMUL_CONTINUE 0
	50	/* Access is unhandleable: bail from emulation and return error to caller. */
	51	#define X86EMUL_UNHANDLEABLE 1
	52	/* Terminate emulation but return success to the caller. */
	53	#define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */
e680080e GN	54	#define X86EMUL_RETRY_INSTR 3 /* retry the instruction for some reason */
e680080e GN	55	#define X86EMUL_CMPXCHG_FAILED 4 /* cmpxchg did not see expected value */
c3cd7ffa	56	#define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */
e680080e	57
6aa8b732 AK	58	struct x86_emulate_ops {
	59	/*
	60	* read_std: Read bytes of standard (non-emulated/special) memory.
1871c602	61	* Used for descriptor reading.
6aa8b732 AK	62	* @addr: [IN ] Linear address from which to read.
	63	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	64	* @bytes: [IN ] Number of bytes to read from memory.
	65	*/
4c690a1e	66	int (read_std)(unsigned long addr, void val,
1871c602 GN	67	unsigned int bytes, struct kvm_vcpu vcpu, u32 error);
1871c602 GN	68
2dafc6c2 GN	69	/*
	70	* write_std: Write bytes of standard (non-emulated/special) memory.
	71	* Used for descriptor writing.
	72	* @addr: [IN ] Linear address to which to write.
	73	* @val: [OUT] Value write to memory, zero-extended to 'u_long'.
	74	* @bytes: [IN ] Number of bytes to write to memory.
	75	*/
	76	int (write_std)(unsigned long addr, void val,
	77	unsigned int bytes, struct kvm_vcpu vcpu, u32 error);
1871c602 GN	78	/*
	79	* fetch: Read bytes of standard (non-emulated/special) memory.
	80	* Used for instruction fetch.
	81	* @addr: [IN ] Linear address from which to read.
	82	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	83	* @bytes: [IN ] Number of bytes to read from memory.
	84	*/
	85	int (fetch)(unsigned long addr, void val,
	86	unsigned int bytes, struct kvm_vcpu vcpu, u32 error);
6aa8b732 AK	87
	88	/*
	89	* read_emulated: Read bytes from emulated/special memory area.
	90	* @addr: [IN ] Linear address from which to read.
	91	* @val: [OUT] Value read from memory, zero-extended to 'u_long'.
	92	* @bytes: [IN ] Number of bytes to read from memory.
	93	*/
0c7825e6 JP	94	int (*read_emulated)(unsigned long addr,
	95	void *val,
	96	unsigned int bytes,
8fe681e9	97	unsigned int *error,
0c7825e6	98	struct kvm_vcpu *vcpu);
6aa8b732 AK	99
6aa8b732 AK	100	/*
0d178975	101	* write_emulated: Write bytes to emulated/special memory area.
6aa8b732 AK	102	* @addr: [IN ] Linear address to which to write.
	103	* @val: [IN ] Value to write to memory (low-order bytes used as
	104	* required).
	105	* @bytes: [IN ] Number of bytes to write to memory.
	106	*/
0c7825e6 JP	107	int (*write_emulated)(unsigned long addr,
	108	const void *val,
	109	unsigned int bytes,
8fe681e9	110	unsigned int *error,
0c7825e6	111	struct kvm_vcpu *vcpu);
6aa8b732 AK	112
	113	/*
	114	* cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an
	115	* emulated/special memory area.
	116	* @addr: [IN ] Linear address to access.
	117	* @old: [IN ] Value expected to be current at @addr.
	118	* @new: [IN ] Value to write to @addr.
	119	* @bytes: [IN ] Number of bytes to access using CMPXCHG.
	120	*/
0c7825e6 JP	121	int (*cmpxchg_emulated)(unsigned long addr,
	122	const void *old,
	123	const void *new,
	124	unsigned int bytes,
8fe681e9	125	unsigned int *error,
0c7825e6	126	struct kvm_vcpu *vcpu);
cf8f70bf GN	127
	128	int (pio_in_emulated)(int size, unsigned short port, void val,
	129	unsigned int count, struct kvm_vcpu *vcpu);
	130
	131	int (pio_out_emulated)(int size, unsigned short port, const void val,
	132	unsigned int count, struct kvm_vcpu *vcpu);
	133
2dafc6c2 GN	134	bool (get_cached_descriptor)(struct desc_struct desc,
	135	int seg, struct kvm_vcpu *vcpu);
	136	void (set_cached_descriptor)(struct desc_struct desc,
	137	int seg, struct kvm_vcpu *vcpu);
	138	u16 (get_segment_selector)(int seg, struct kvm_vcpu vcpu);
	139	void (set_segment_selector)(u16 sel, int seg, struct kvm_vcpu vcpu);
5951c442	140	unsigned long (get_cached_segment_base)(int seg, struct kvm_vcpu vcpu);
2dafc6c2	141	void (get_gdt)(struct desc_ptr dt, struct kvm_vcpu *vcpu);
52a46617	142	ulong (get_cr)(int cr, struct kvm_vcpu vcpu);
0f12244f	143	int (set_cr)(int cr, ulong val, struct kvm_vcpu vcpu);
9c537244	144	int (cpl)(struct kvm_vcpu vcpu);
35aa5375 GN	145	int (get_dr)(int dr, unsigned long dest, struct kvm_vcpu *vcpu);
35aa5375 GN	146	int (set_dr)(int dr, unsigned long value, struct kvm_vcpu vcpu);
3fb1b5db GN	147	int (set_msr)(struct kvm_vcpu vcpu, u32 msr_index, u64 data);
3fb1b5db GN	148	int (get_msr)(struct kvm_vcpu vcpu, u32 msr_index, u64 *pdata);
6aa8b732 AK	149	};
6aa8b732 AK	150
e4e03ded LV	151	/* Type, address-of, and value of an instruction's operand. */
e4e03ded LV	152	struct operand {
a01af5ec	153	enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type;
e4e03ded	154	unsigned int bytes;
16518d5a AK	155	union {
	156	unsigned long orig_val;
	157	u64 orig_val64;
	158	};
	159	unsigned long *ptr;
414e6277 GN	160	union {
414e6277 GN	161	unsigned long val;
16518d5a	162	u64 val64;
414e6277 GN	163	char valptr[sizeof(unsigned long) + 2];
414e6277 GN	164	};
e4e03ded LV	165	};
e4e03ded LV	166
62266869 AK	167	struct fetch_cache {
	168	u8 data[15];
	169	unsigned long start;
	170	unsigned long end;
	171	};
	172
7b262e90 GN	173	struct read_cache {
	174	u8 data[1024];
	175	unsigned long pos;
	176	unsigned long end;
	177	};
	178
e4e03ded LV	179	struct decode_cache {
	180	u8 twobyte;
	181	u8 b;
	182	u8 lock_prefix;
	183	u8 rep_prefix;
	184	u8 op_bytes;
	185	u8 ad_bytes;
33615aa9	186	u8 rex_prefix;
e4e03ded	187	struct operand src;
0dc8d10f	188	struct operand src2;
e4e03ded	189	struct operand dst;
7a5b56df AK	190	bool has_seg_override;
7a5b56df AK	191	u8 seg_override;
e4e03ded LV	192	unsigned int d;
e4e03ded LV	193	unsigned long regs[NR_VCPU_REGS];
063db061	194	unsigned long eip;
e4e03ded LV	195	/* modrm */
	196	u8 modrm;
	197	u8 modrm_mod;
	198	u8 modrm_reg;
	199	u8 modrm_rm;
	200	u8 use_modrm_ea;
f5b4edcd	201	bool rip_relative;
e4e03ded	202	unsigned long modrm_ea;
107d6d2e	203	void *modrm_ptr;
e4e03ded	204	unsigned long modrm_val;
62266869	205	struct fetch_cache fetch;
7b262e90	206	struct read_cache io_read;
9de41573	207	struct read_cache mem_read;
e4e03ded LV	208	};
e4e03ded LV	209
6aa8b732 AK	210	struct x86_emulate_ctxt {
	211	/* Register state before/after emulation. */
	212	struct kvm_vcpu *vcpu;
	213
6aa8b732	214	unsigned long eflags;
063db061	215	unsigned long eip; /* eip before instruction emulation */
6aa8b732 AK	216	/* Emulated execution mode, represented by an X86EMUL_MODE value. */
6aa8b732 AK	217	int mode;
7a5b56df	218	u32 cs_base;
e4e03ded	219
310b5d30 GC	220	/* interruptibility state, as a result of execution of STI or MOV SS */
	221	int interruptibility;
	222
5cd21917	223	bool restart; /* restart string instruction after writeback */
54b8486f GN	224
	225	int exception; /* exception that happens during emulation or -1 */
	226	u32 error_code; /* error code for exception */
	227	bool error_code_valid;
	228	unsigned long cr2; /* faulted address in case of #PF */
	229
e4e03ded	230	/* decode cache */
e4e03ded	231	struct decode_cache decode;
6aa8b732 AK	232	};
6aa8b732 AK	233
90e0a28f	234	/* Repeat String Operation Prefix */
d73fa29a SY	235	#define REPE_PREFIX 1
d73fa29a SY	236	#define REPNE_PREFIX 2
90e0a28f	237
6aa8b732 AK	238	/* Execution mode, passed to the emulator. */
6aa8b732 AK	239	#define X86EMUL_MODE_REAL 0 /* Real mode. */
a0044755	240	#define X86EMUL_MODE_VM86 1 /* Virtual 8086 mode. */
6aa8b732 AK	241	#define X86EMUL_MODE_PROT16 2 /* 16-bit protected mode. */
	242	#define X86EMUL_MODE_PROT32 4 /* 32-bit protected mode. */
	243	#define X86EMUL_MODE_PROT64 8 /* 64-bit (long) mode. */
	244
	245	/* Host execution mode. */
d73fa29a	246	#if defined(CONFIG_X86_32)
6aa8b732	247	#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32
05b3e0c2	248	#elif defined(CONFIG_X86_64)
6aa8b732 AK	249	#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64
	250	#endif
	251
1be3aa47 LV	252	int x86_decode_insn(struct x86_emulate_ctxt *ctxt,
	253	struct x86_emulate_ops *ops);
	254	int x86_emulate_insn(struct x86_emulate_ctxt *ctxt,
	255	struct x86_emulate_ops *ops);
38ba30ba GN	256	int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
38ba30ba GN	257	struct x86_emulate_ops *ops,
e269fb21 JK	258	u16 tss_selector, int reason,
e269fb21 JK	259	bool has_error_code, u32 error_code);
6aa8b732	260
1965aae3	261	#endif /* _ASM_X86_KVM_X86_EMULATE_H */