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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 |
12 | #define _ASM_X86_KVM_X86_EMULATE_H | |
6aa8b732 | 13 | |
38ba30ba GN |
14 | #include <asm/desc_defs.h> |
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 */ | |
54 | #define X86EMUL_RETRY_INSTR 2 /* retry the instruction for some reason */ | |
55 | #define X86EMUL_CMPXCHG_FAILED 2 /* cmpxchg did not see expected value */ | |
56 | struct x86_emulate_ops { | |
57 | /* | |
58 | * read_std: Read bytes of standard (non-emulated/special) memory. | |
1871c602 | 59 | * Used for descriptor reading. |
6aa8b732 AK |
60 | * @addr: [IN ] Linear address from which to read. |
61 | * @val: [OUT] Value read from memory, zero-extended to 'u_long'. | |
62 | * @bytes: [IN ] Number of bytes to read from memory. | |
63 | */ | |
4c690a1e | 64 | int (*read_std)(unsigned long addr, void *val, |
1871c602 GN |
65 | unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error); |
66 | ||
2dafc6c2 GN |
67 | /* |
68 | * write_std: Write bytes of standard (non-emulated/special) memory. | |
69 | * Used for descriptor writing. | |
70 | * @addr: [IN ] Linear address to which to write. | |
71 | * @val: [OUT] Value write to memory, zero-extended to 'u_long'. | |
72 | * @bytes: [IN ] Number of bytes to write to memory. | |
73 | */ | |
74 | int (*write_std)(unsigned long addr, void *val, | |
75 | unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error); | |
1871c602 GN |
76 | /* |
77 | * fetch: Read bytes of standard (non-emulated/special) memory. | |
78 | * Used for instruction fetch. | |
79 | * @addr: [IN ] Linear address from which to read. | |
80 | * @val: [OUT] Value read from memory, zero-extended to 'u_long'. | |
81 | * @bytes: [IN ] Number of bytes to read from memory. | |
82 | */ | |
83 | int (*fetch)(unsigned long addr, void *val, | |
84 | unsigned int bytes, struct kvm_vcpu *vcpu, u32 *error); | |
6aa8b732 AK |
85 | |
86 | /* | |
87 | * read_emulated: Read bytes from emulated/special memory area. | |
88 | * @addr: [IN ] Linear address from which to read. | |
89 | * @val: [OUT] Value read from memory, zero-extended to 'u_long'. | |
90 | * @bytes: [IN ] Number of bytes to read from memory. | |
91 | */ | |
0c7825e6 JP |
92 | int (*read_emulated)(unsigned long addr, |
93 | void *val, | |
94 | unsigned int bytes, | |
95 | struct kvm_vcpu *vcpu); | |
6aa8b732 AK |
96 | |
97 | /* | |
0d178975 | 98 | * write_emulated: Write bytes to emulated/special memory area. |
6aa8b732 AK |
99 | * @addr: [IN ] Linear address to which to write. |
100 | * @val: [IN ] Value to write to memory (low-order bytes used as | |
101 | * required). | |
102 | * @bytes: [IN ] Number of bytes to write to memory. | |
103 | */ | |
0c7825e6 JP |
104 | int (*write_emulated)(unsigned long addr, |
105 | const void *val, | |
106 | unsigned int bytes, | |
107 | struct kvm_vcpu *vcpu); | |
6aa8b732 AK |
108 | |
109 | /* | |
110 | * cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an | |
111 | * emulated/special memory area. | |
112 | * @addr: [IN ] Linear address to access. | |
113 | * @old: [IN ] Value expected to be current at @addr. | |
114 | * @new: [IN ] Value to write to @addr. | |
115 | * @bytes: [IN ] Number of bytes to access using CMPXCHG. | |
116 | */ | |
0c7825e6 JP |
117 | int (*cmpxchg_emulated)(unsigned long addr, |
118 | const void *old, | |
119 | const void *new, | |
120 | unsigned int bytes, | |
121 | struct kvm_vcpu *vcpu); | |
2dafc6c2 GN |
122 | bool (*get_cached_descriptor)(struct desc_struct *desc, |
123 | int seg, struct kvm_vcpu *vcpu); | |
124 | void (*set_cached_descriptor)(struct desc_struct *desc, | |
125 | int seg, struct kvm_vcpu *vcpu); | |
126 | u16 (*get_segment_selector)(int seg, struct kvm_vcpu *vcpu); | |
127 | void (*set_segment_selector)(u16 sel, int seg, struct kvm_vcpu *vcpu); | |
128 | void (*get_gdt)(struct desc_ptr *dt, struct kvm_vcpu *vcpu); | |
52a46617 GN |
129 | ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu); |
130 | void (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu); | |
9c537244 | 131 | int (*cpl)(struct kvm_vcpu *vcpu); |
6aa8b732 AK |
132 | }; |
133 | ||
e4e03ded LV |
134 | /* Type, address-of, and value of an instruction's operand. */ |
135 | struct operand { | |
a01af5ec | 136 | enum { OP_REG, OP_MEM, OP_IMM, OP_NONE } type; |
e4e03ded LV |
137 | unsigned int bytes; |
138 | unsigned long val, orig_val, *ptr; | |
139 | }; | |
140 | ||
62266869 AK |
141 | struct fetch_cache { |
142 | u8 data[15]; | |
143 | unsigned long start; | |
144 | unsigned long end; | |
145 | }; | |
146 | ||
e4e03ded LV |
147 | struct decode_cache { |
148 | u8 twobyte; | |
149 | u8 b; | |
150 | u8 lock_prefix; | |
151 | u8 rep_prefix; | |
152 | u8 op_bytes; | |
153 | u8 ad_bytes; | |
33615aa9 | 154 | u8 rex_prefix; |
e4e03ded | 155 | struct operand src; |
0dc8d10f | 156 | struct operand src2; |
e4e03ded | 157 | struct operand dst; |
7a5b56df AK |
158 | bool has_seg_override; |
159 | u8 seg_override; | |
e4e03ded LV |
160 | unsigned int d; |
161 | unsigned long regs[NR_VCPU_REGS]; | |
063db061 | 162 | unsigned long eip; |
e4e03ded LV |
163 | /* modrm */ |
164 | u8 modrm; | |
165 | u8 modrm_mod; | |
166 | u8 modrm_reg; | |
167 | u8 modrm_rm; | |
168 | u8 use_modrm_ea; | |
f5b4edcd | 169 | bool rip_relative; |
e4e03ded | 170 | unsigned long modrm_ea; |
107d6d2e | 171 | void *modrm_ptr; |
e4e03ded | 172 | unsigned long modrm_val; |
62266869 | 173 | struct fetch_cache fetch; |
e4e03ded LV |
174 | }; |
175 | ||
6aa8b732 AK |
176 | struct x86_emulate_ctxt { |
177 | /* Register state before/after emulation. */ | |
178 | struct kvm_vcpu *vcpu; | |
179 | ||
6aa8b732 | 180 | unsigned long eflags; |
063db061 | 181 | unsigned long eip; /* eip before instruction emulation */ |
6aa8b732 AK |
182 | /* Emulated execution mode, represented by an X86EMUL_MODE value. */ |
183 | int mode; | |
7a5b56df | 184 | u32 cs_base; |
e4e03ded | 185 | |
310b5d30 GC |
186 | /* interruptibility state, as a result of execution of STI or MOV SS */ |
187 | int interruptibility; | |
188 | ||
e4e03ded | 189 | /* decode cache */ |
e4e03ded | 190 | struct decode_cache decode; |
6aa8b732 AK |
191 | }; |
192 | ||
90e0a28f | 193 | /* Repeat String Operation Prefix */ |
d73fa29a SY |
194 | #define REPE_PREFIX 1 |
195 | #define REPNE_PREFIX 2 | |
90e0a28f | 196 | |
6aa8b732 AK |
197 | /* Execution mode, passed to the emulator. */ |
198 | #define X86EMUL_MODE_REAL 0 /* Real mode. */ | |
a0044755 | 199 | #define X86EMUL_MODE_VM86 1 /* Virtual 8086 mode. */ |
6aa8b732 AK |
200 | #define X86EMUL_MODE_PROT16 2 /* 16-bit protected mode. */ |
201 | #define X86EMUL_MODE_PROT32 4 /* 32-bit protected mode. */ | |
202 | #define X86EMUL_MODE_PROT64 8 /* 64-bit (long) mode. */ | |
203 | ||
204 | /* Host execution mode. */ | |
d73fa29a | 205 | #if defined(CONFIG_X86_32) |
6aa8b732 | 206 | #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32 |
05b3e0c2 | 207 | #elif defined(CONFIG_X86_64) |
6aa8b732 AK |
208 | #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64 |
209 | #endif | |
210 | ||
1be3aa47 LV |
211 | int x86_decode_insn(struct x86_emulate_ctxt *ctxt, |
212 | struct x86_emulate_ops *ops); | |
213 | int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, | |
214 | struct x86_emulate_ops *ops); | |
38ba30ba GN |
215 | int emulator_task_switch(struct x86_emulate_ctxt *ctxt, |
216 | struct x86_emulate_ops *ops, | |
217 | u16 tss_selector, int reason); | |
6aa8b732 | 218 | |
1965aae3 | 219 | #endif /* _ASM_X86_KVM_X86_EMULATE_H */ |