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Fix a race condition in FASYNC handling
[linux-2.6/zen-sources.git] / arch / x86 / kvm / x86_emulate.c
blobea051173b0da9e950ca92d6841a42c507e957444
1 /******************************************************************************
2 * x86_emulate.c
3 *
4 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
5 *
6 * Copyright (c) 2005 Keir Fraser
7 *
8 * Linux coding style, mod r/m decoder, segment base fixes, real-mode
9 * privileged instructions:
10 *
11 * Copyright (C) 2006 Qumranet
12 *
13 * Avi Kivity <avi@qumranet.com>
14 * Yaniv Kamay <yaniv@qumranet.com>
15 *
16 * This work is licensed under the terms of the GNU GPL, version 2. See
17 * the COPYING file in the top-level directory.
18 *
19 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
20 */
21
22 #ifndef __KERNEL__
23 #include <stdio.h>
24 #include <stdint.h>
25 #include <public/xen.h>
26 #define DPRINTF(_f, _a ...) printf(_f , ## _a)
27 #else
28 #include <linux/kvm_host.h>
29 #include "kvm_cache_regs.h"
30 #define DPRINTF(x...) do {} while (0)
31 #endif
32 #include <linux/module.h>
33 #include <asm/kvm_x86_emulate.h>
34
35 /*
36 * Opcode effective-address decode tables.
37 * Note that we only emulate instructions that have at least one memory
38 * operand (excluding implicit stack references). We assume that stack
39 * references and instruction fetches will never occur in special memory
40 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
41 * not be handled.
42 */
43
44 /* Operand sizes: 8-bit operands or specified/overridden size. */
45 #define ByteOp (1<<0) /* 8-bit operands. */
46 /* Destination operand type. */
47 #define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */
48 #define DstReg (2<<1) /* Register operand. */
49 #define DstMem (3<<1) /* Memory operand. */
50 #define DstAcc (4<<1) /* Destination Accumulator */
51 #define DstMask (7<<1)
52 /* Source operand type. */
53 #define SrcNone (0<<4) /* No source operand. */
54 #define SrcImplicit (0<<4) /* Source operand is implicit in the opcode. */
55 #define SrcReg (1<<4) /* Register operand. */
56 #define SrcMem (2<<4) /* Memory operand. */
57 #define SrcMem16 (3<<4) /* Memory operand (16-bit). */
58 #define SrcMem32 (4<<4) /* Memory operand (32-bit). */
59 #define SrcImm (5<<4) /* Immediate operand. */
60 #define SrcImmByte (6<<4) /* 8-bit sign-extended immediate operand. */
61 #define SrcMask (7<<4)
62 /* Generic ModRM decode. */
63 #define ModRM (1<<7)
64 /* Destination is only written; never read. */
65 #define Mov (1<<8)
66 #define BitOp (1<<9)
67 #define MemAbs (1<<10) /* Memory operand is absolute displacement */
68 #define String (1<<12) /* String instruction (rep capable) */
69 #define Stack (1<<13) /* Stack instruction (push/pop) */
70 #define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */
71 #define GroupDual (1<<15) /* Alternate decoding of mod == 3 */
72 #define GroupMask 0xff /* Group number stored in bits 0:7 */
73
74 enum {
75 Group1_80, Group1_81, Group1_82, Group1_83,
76 Group1A, Group3_Byte, Group3, Group4, Group5, Group7,
77 };
78
79 static u16 opcode_table[256] = {
80 /* 0x00 - 0x07 */
81 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
82 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
83 0, 0, 0, 0,
84 /* 0x08 - 0x0F */
85 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
86 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
87 0, 0, 0, 0,
88 /* 0x10 - 0x17 */
89 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
90 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
91 0, 0, 0, 0,
92 /* 0x18 - 0x1F */
93 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
94 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
95 0, 0, 0, 0,
96 /* 0x20 - 0x27 */
97 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
98 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
99 DstAcc | SrcImmByte, DstAcc | SrcImm, 0, 0,
100 /* 0x28 - 0x2F */
101 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
102 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
103 0, 0, 0, 0,
104 /* 0x30 - 0x37 */
105 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
106 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
107 0, 0, 0, 0,
108 /* 0x38 - 0x3F */
109 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
110 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
111 ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
112 0, 0,
113 /* 0x40 - 0x47 */
114 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg,
115 /* 0x48 - 0x4F */
116 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg,
117 /* 0x50 - 0x57 */
118 SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack,
119 SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack,
120 /* 0x58 - 0x5F */
121 DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack,
122 DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack,
123 /* 0x60 - 0x67 */
124 0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ ,
125 0, 0, 0, 0,
126 /* 0x68 - 0x6F */
127 SrcImm | Mov | Stack, 0, SrcImmByte | Mov | Stack, 0,
128 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* insb, insw/insd */
129 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* outsb, outsw/outsd */
130 /* 0x70 - 0x77 */
131 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
132 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
133 /* 0x78 - 0x7F */
134 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
135 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
136 /* 0x80 - 0x87 */
137 Group | Group1_80, Group | Group1_81,
138 Group | Group1_82, Group | Group1_83,
139 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
140 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
141 /* 0x88 - 0x8F */
142 ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov,
143 ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
144 DstMem | SrcReg | ModRM | Mov, ModRM | DstReg,
145 DstReg | SrcMem | ModRM | Mov, Group | Group1A,
146 /* 0x90 - 0x97 */
147 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg,
148 /* 0x98 - 0x9F */
149 0, 0, 0, 0, ImplicitOps | Stack, ImplicitOps | Stack, 0, 0,
150 /* 0xA0 - 0xA7 */
151 ByteOp | DstReg | SrcMem | Mov | MemAbs, DstReg | SrcMem | Mov | MemAbs,
152 ByteOp | DstMem | SrcReg | Mov | MemAbs, DstMem | SrcReg | Mov | MemAbs,
153 ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String,
154 ByteOp | ImplicitOps | String, ImplicitOps | String,
155 /* 0xA8 - 0xAF */
156 0, 0, ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String,
157 ByteOp | ImplicitOps | Mov | String, ImplicitOps | Mov | String,
158 ByteOp | ImplicitOps | String, ImplicitOps | String,
159 /* 0xB0 - 0xB7 */
160 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
161 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
162 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
163 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
164 /* 0xB8 - 0xBF */
165 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
166 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
167 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
168 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
169 /* 0xC0 - 0xC7 */
170 ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM,
171 0, ImplicitOps | Stack, 0, 0,
172 ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov,
173 /* 0xC8 - 0xCF */
174 0, 0, 0, 0, 0, 0, 0, 0,
175 /* 0xD0 - 0xD7 */
176 ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM,
177 ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM,
178 0, 0, 0, 0,
179 /* 0xD8 - 0xDF */
180 0, 0, 0, 0, 0, 0, 0, 0,
181 /* 0xE0 - 0xE7 */
182 0, 0, 0, 0,
183 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
184 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
185 /* 0xE8 - 0xEF */
186 ImplicitOps | Stack, SrcImm | ImplicitOps,
187 ImplicitOps, SrcImmByte | ImplicitOps,
188 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
189 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps,
190 /* 0xF0 - 0xF7 */
191 0, 0, 0, 0,
192 ImplicitOps, ImplicitOps, Group | Group3_Byte, Group | Group3,
193 /* 0xF8 - 0xFF */
194 ImplicitOps, 0, ImplicitOps, ImplicitOps,
195 ImplicitOps, ImplicitOps, Group | Group4, Group | Group5,
196 };
197
198 static u16 twobyte_table[256] = {
199 /* 0x00 - 0x0F */
200 0, Group | GroupDual | Group7, 0, 0, 0, 0, ImplicitOps, 0,
201 ImplicitOps, ImplicitOps, 0, 0, 0, ImplicitOps | ModRM, 0, 0,
202 /* 0x10 - 0x1F */
203 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0,
204 /* 0x20 - 0x2F */
205 ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0,
206 0, 0, 0, 0, 0, 0, 0, 0,
207 /* 0x30 - 0x3F */
208 ImplicitOps, 0, ImplicitOps, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
209 /* 0x40 - 0x47 */
210 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
211 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
212 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
213 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
214 /* 0x48 - 0x4F */
215 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
216 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
217 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
218 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
219 /* 0x50 - 0x5F */
220 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
221 /* 0x60 - 0x6F */
222 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
223 /* 0x70 - 0x7F */
224 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
225 /* 0x80 - 0x8F */
226 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
227 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
228 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
229 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
230 /* 0x90 - 0x9F */
231 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
232 /* 0xA0 - 0xA7 */
233 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0,
234 /* 0xA8 - 0xAF */
235 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, ModRM, 0,
236 /* 0xB0 - 0xB7 */
237 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0,
238 DstMem | SrcReg | ModRM | BitOp,
239 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
240 DstReg | SrcMem16 | ModRM | Mov,
241 /* 0xB8 - 0xBF */
242 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM | BitOp,
243 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
244 DstReg | SrcMem16 | ModRM | Mov,
245 /* 0xC0 - 0xCF */
246 0, 0, 0, DstMem | SrcReg | ModRM | Mov, 0, 0, 0, ImplicitOps | ModRM,
247 0, 0, 0, 0, 0, 0, 0, 0,
248 /* 0xD0 - 0xDF */
249 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
250 /* 0xE0 - 0xEF */
251 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
252 /* 0xF0 - 0xFF */
253 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
254 };
255
256 static u16 group_table[] = {
257 [Group1_80*8] =
258 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
259 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
260 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
261 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
262 [Group1_81*8] =
263 DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
264 DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
265 DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
266 DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
267 [Group1_82*8] =
268 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
269 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
270 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
271 ByteOp | DstMem | SrcImm | ModRM, ByteOp | DstMem | SrcImm | ModRM,
272 [Group1_83*8] =
273 DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
274 DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
275 DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
276 DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM,
277 [Group1A*8] =
278 DstMem | SrcNone | ModRM | Mov | Stack, 0, 0, 0, 0, 0, 0, 0,
279 [Group3_Byte*8] =
280 ByteOp | SrcImm | DstMem | ModRM, 0,
281 ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM,
282 0, 0, 0, 0,
283 [Group3*8] =
284 DstMem | SrcImm | ModRM, 0,
285 DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
286 0, 0, 0, 0,
287 [Group4*8] =
288 ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM,
289 0, 0, 0, 0, 0, 0,
290 [Group5*8] =
291 DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
292 SrcMem | ModRM | Stack, 0,
293 SrcMem | ModRM | Stack, 0, SrcMem | ModRM | Stack, 0,
294 [Group7*8] =
295 0, 0, ModRM | SrcMem, ModRM | SrcMem,
296 SrcNone | ModRM | DstMem | Mov, 0,
297 SrcMem16 | ModRM | Mov, SrcMem | ModRM | ByteOp,
298 };
299
300 static u16 group2_table[] = {
301 [Group7*8] =
302 SrcNone | ModRM, 0, 0, 0,
303 SrcNone | ModRM | DstMem | Mov, 0,
304 SrcMem16 | ModRM | Mov, 0,
305 };
306
307 /* EFLAGS bit definitions. */
308 #define EFLG_OF (1<<11)
309 #define EFLG_DF (1<<10)
310 #define EFLG_SF (1<<7)
311 #define EFLG_ZF (1<<6)
312 #define EFLG_AF (1<<4)
313 #define EFLG_PF (1<<2)
314 #define EFLG_CF (1<<0)
315
316 /*
317 * Instruction emulation:
318 * Most instructions are emulated directly via a fragment of inline assembly
319 * code. This allows us to save/restore EFLAGS and thus very easily pick up
320 * any modified flags.
321 */
322
323 #if defined(CONFIG_X86_64)
324 #define _LO32 "k" /* force 32-bit operand */
325 #define _STK "%%rsp" /* stack pointer */
326 #elif defined(__i386__)
327 #define _LO32 "" /* force 32-bit operand */
328 #define _STK "%%esp" /* stack pointer */
329 #endif
330
331 /*
332 * These EFLAGS bits are restored from saved value during emulation, and
333 * any changes are written back to the saved value after emulation.
334 */
335 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
336
337 /* Before executing instruction: restore necessary bits in EFLAGS. */
338 #define _PRE_EFLAGS(_sav, _msk, _tmp) \
339 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \
340 "movl %"_sav",%"_LO32 _tmp"; " \
341 "push %"_tmp"; " \
342 "push %"_tmp"; " \
343 "movl %"_msk",%"_LO32 _tmp"; " \
344 "andl %"_LO32 _tmp",("_STK"); " \
345 "pushf; " \
346 "notl %"_LO32 _tmp"; " \
347 "andl %"_LO32 _tmp",("_STK"); " \
348 "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \
349 "pop %"_tmp"; " \
350 "orl %"_LO32 _tmp",("_STK"); " \
351 "popf; " \
352 "pop %"_sav"; "
353
354 /* After executing instruction: write-back necessary bits in EFLAGS. */
355 #define _POST_EFLAGS(_sav, _msk, _tmp) \
356 /* _sav |= EFLAGS & _msk; */ \
357 "pushf; " \
358 "pop %"_tmp"; " \
359 "andl %"_msk",%"_LO32 _tmp"; " \
360 "orl %"_LO32 _tmp",%"_sav"; "
361
362 /* Raw emulation: instruction has two explicit operands. */
363 #define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \
364 do { \
365 unsigned long _tmp; \
366 \
367 switch ((_dst).bytes) { \
368 case 2: \
369 __asm__ __volatile__ ( \
370 _PRE_EFLAGS("0", "4", "2") \
371 _op"w %"_wx"3,%1; " \
372 _POST_EFLAGS("0", "4", "2") \
373 : "=m" (_eflags), "=m" ((_dst).val), \
374 "=&r" (_tmp) \
375 : _wy ((_src).val), "i" (EFLAGS_MASK)); \
376 break; \
377 case 4: \
378 __asm__ __volatile__ ( \
379 _PRE_EFLAGS("0", "4", "2") \
380 _op"l %"_lx"3,%1; " \
381 _POST_EFLAGS("0", "4", "2") \
382 : "=m" (_eflags), "=m" ((_dst).val), \
383 "=&r" (_tmp) \
384 : _ly ((_src).val), "i" (EFLAGS_MASK)); \
385 break; \
386 case 8: \
387 __emulate_2op_8byte(_op, _src, _dst, \
388 _eflags, _qx, _qy); \
389 break; \
390 } \
391 } while (0)
392
393 #define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \
394 do { \
395 unsigned long __tmp; \
396 switch ((_dst).bytes) { \
397 case 1: \
398 __asm__ __volatile__ ( \
399 _PRE_EFLAGS("0", "4", "2") \
400 _op"b %"_bx"3,%1; " \
401 _POST_EFLAGS("0", "4", "2") \
402 : "=m" (_eflags), "=m" ((_dst).val), \
403 "=&r" (__tmp) \
404 : _by ((_src).val), "i" (EFLAGS_MASK)); \
405 break; \
406 default: \
407 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
408 _wx, _wy, _lx, _ly, _qx, _qy); \
409 break; \
410 } \
411 } while (0)
412
413 /* Source operand is byte-sized and may be restricted to just %cl. */
414 #define emulate_2op_SrcB(_op, _src, _dst, _eflags) \
415 __emulate_2op(_op, _src, _dst, _eflags, \
416 "b", "c", "b", "c", "b", "c", "b", "c")
417
418 /* Source operand is byte, word, long or quad sized. */
419 #define emulate_2op_SrcV(_op, _src, _dst, _eflags) \
420 __emulate_2op(_op, _src, _dst, _eflags, \
421 "b", "q", "w", "r", _LO32, "r", "", "r")
422
423 /* Source operand is word, long or quad sized. */
424 #define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \
425 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
426 "w", "r", _LO32, "r", "", "r")
427
428 /* Instruction has only one explicit operand (no source operand). */
429 #define emulate_1op(_op, _dst, _eflags) \
430 do { \
431 unsigned long _tmp; \
432 \
433 switch ((_dst).bytes) { \
434 case 1: \
435 __asm__ __volatile__ ( \
436 _PRE_EFLAGS("0", "3", "2") \
437 _op"b %1; " \
438 _POST_EFLAGS("0", "3", "2") \
439 : "=m" (_eflags), "=m" ((_dst).val), \
440 "=&r" (_tmp) \
441 : "i" (EFLAGS_MASK)); \
442 break; \
443 case 2: \
444 __asm__ __volatile__ ( \
445 _PRE_EFLAGS("0", "3", "2") \
446 _op"w %1; " \
447 _POST_EFLAGS("0", "3", "2") \
448 : "=m" (_eflags), "=m" ((_dst).val), \
449 "=&r" (_tmp) \
450 : "i" (EFLAGS_MASK)); \
451 break; \
452 case 4: \
453 __asm__ __volatile__ ( \
454 _PRE_EFLAGS("0", "3", "2") \
455 _op"l %1; " \
456 _POST_EFLAGS("0", "3", "2") \
457 : "=m" (_eflags), "=m" ((_dst).val), \
458 "=&r" (_tmp) \
459 : "i" (EFLAGS_MASK)); \
460 break; \
461 case 8: \
462 __emulate_1op_8byte(_op, _dst, _eflags); \
463 break; \
464 } \
465 } while (0)
466
467 /* Emulate an instruction with quadword operands (x86/64 only). */
468 #if defined(CONFIG_X86_64)
469 #define __emulate_2op_8byte(_op, _src, _dst, _eflags, _qx, _qy) \
470 do { \
471 __asm__ __volatile__ ( \
472 _PRE_EFLAGS("0", "4", "2") \
473 _op"q %"_qx"3,%1; " \
474 _POST_EFLAGS("0", "4", "2") \
475 : "=m" (_eflags), "=m" ((_dst).val), "=&r" (_tmp) \
476 : _qy ((_src).val), "i" (EFLAGS_MASK)); \
477 } while (0)
478
479 #define __emulate_1op_8byte(_op, _dst, _eflags) \
480 do { \
481 __asm__ __volatile__ ( \
482 _PRE_EFLAGS("0", "3", "2") \
483 _op"q %1; " \
484 _POST_EFLAGS("0", "3", "2") \
485 : "=m" (_eflags), "=m" ((_dst).val), "=&r" (_tmp) \
486 : "i" (EFLAGS_MASK)); \
487 } while (0)
488
489 #elif defined(__i386__)
490 #define __emulate_2op_8byte(_op, _src, _dst, _eflags, _qx, _qy)
491 #define __emulate_1op_8byte(_op, _dst, _eflags)
492 #endif /* __i386__ */
493
494 /* Fetch next part of the instruction being emulated. */
495 #define insn_fetch(_type, _size, _eip) \
496 ({ unsigned long _x; \
497 rc = do_insn_fetch(ctxt, ops, (_eip), &_x, (_size)); \
498 if (rc != 0) \
499 goto done; \
500 (_eip) += (_size); \
501 (_type)_x; \
502 })
503
504 static inline unsigned long ad_mask(struct decode_cache *c)
505 {
506 return (1UL << (c->ad_bytes << 3)) - 1;
507 }
508
509 /* Access/update address held in a register, based on addressing mode. */
510 static inline unsigned long
511 address_mask(struct decode_cache *c, unsigned long reg)
512 {
513 if (c->ad_bytes == sizeof(unsigned long))
514 return reg;
515 else
516 return reg & ad_mask(c);
517 }
518
519 static inline unsigned long
520 register_address(struct decode_cache *c, unsigned long base, unsigned long reg)
521 {
522 return base + address_mask(c, reg);
523 }
524
525 static inline void
526 register_address_increment(struct decode_cache *c, unsigned long *reg, int inc)
527 {
528 if (c->ad_bytes == sizeof(unsigned long))
529 *reg += inc;
530 else
531 *reg = (*reg & ~ad_mask(c)) | ((*reg + inc) & ad_mask(c));
532 }
533
534 static inline void jmp_rel(struct decode_cache *c, int rel)
535 {
536 register_address_increment(c, &c->eip, rel);
537 }
538
539 static void set_seg_override(struct decode_cache *c, int seg)
540 {
541 c->has_seg_override = true;
542 c->seg_override = seg;
543 }
544
545 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
546 {
547 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
548 return 0;
549
550 return kvm_x86_ops->get_segment_base(ctxt->vcpu, seg);
551 }
552
553 static unsigned long seg_override_base(struct x86_emulate_ctxt *ctxt,
554 struct decode_cache *c)
555 {
556 if (!c->has_seg_override)
557 return 0;
558
559 return seg_base(ctxt, c->seg_override);
560 }
561
562 static unsigned long es_base(struct x86_emulate_ctxt *ctxt)
563 {
564 return seg_base(ctxt, VCPU_SREG_ES);
565 }
566
567 static unsigned long ss_base(struct x86_emulate_ctxt *ctxt)
568 {
569 return seg_base(ctxt, VCPU_SREG_SS);
570 }
571
572 static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
573 struct x86_emulate_ops *ops,
574 unsigned long linear, u8 *dest)
575 {
576 struct fetch_cache *fc = &ctxt->decode.fetch;
577 int rc;
578 int size;
579
580 if (linear < fc->start || linear >= fc->end) {
581 size = min(15UL, PAGE_SIZE - offset_in_page(linear));
582 rc = ops->read_std(linear, fc->data, size, ctxt->vcpu);
583 if (rc)
584 return rc;
585 fc->start = linear;
586 fc->end = linear + size;
587 }
588 *dest = fc->data[linear - fc->start];
589 return 0;
590 }
591
592 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt,
593 struct x86_emulate_ops *ops,
594 unsigned long eip, void *dest, unsigned size)
595 {
596 int rc = 0;
597
598 eip += ctxt->cs_base;
599 while (size--) {
600 rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++);
601 if (rc)
602 return rc;
603 }
604 return 0;
605 }
606
607 /*
608 * Given the 'reg' portion of a ModRM byte, and a register block, return a
609 * pointer into the block that addresses the relevant register.
610 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
611 */
612 static void *decode_register(u8 modrm_reg, unsigned long *regs,
613 int highbyte_regs)
614 {
615 void *p;
616
617 p = &regs[modrm_reg];
618 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
619 p = (unsigned char *)&regs[modrm_reg & 3] + 1;
620 return p;
621 }
622
623 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
624 struct x86_emulate_ops *ops,
625 void *ptr,
626 u16 *size, unsigned long *address, int op_bytes)
627 {
628 int rc;
629
630 if (op_bytes == 2)
631 op_bytes = 3;
632 *address = 0;
633 rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2,
634 ctxt->vcpu);
635 if (rc)
636 return rc;
637 rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes,
638 ctxt->vcpu);
639 return rc;
640 }
641
642 static int test_cc(unsigned int condition, unsigned int flags)
643 {
644 int rc = 0;
645
646 switch ((condition & 15) >> 1) {
647 case 0: /* o */
648 rc |= (flags & EFLG_OF);
649 break;
650 case 1: /* b/c/nae */
651 rc |= (flags & EFLG_CF);
652 break;
653 case 2: /* z/e */
654 rc |= (flags & EFLG_ZF);
655 break;
656 case 3: /* be/na */
657 rc |= (flags & (EFLG_CF|EFLG_ZF));
658 break;
659 case 4: /* s */
660 rc |= (flags & EFLG_SF);
661 break;
662 case 5: /* p/pe */
663 rc |= (flags & EFLG_PF);
664 break;
665 case 7: /* le/ng */
666 rc |= (flags & EFLG_ZF);
667 /* fall through */
668 case 6: /* l/nge */
669 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
670 break;
671 }
672
673 /* Odd condition identifiers (lsb == 1) have inverted sense. */
674 return (!!rc ^ (condition & 1));
675 }
676
677 static void decode_register_operand(struct operand *op,
678 struct decode_cache *c,
679 int inhibit_bytereg)
680 {
681 unsigned reg = c->modrm_reg;
682 int highbyte_regs = c->rex_prefix == 0;
683
684 if (!(c->d & ModRM))
685 reg = (c->b & 7) | ((c->rex_prefix & 1) << 3);
686 op->type = OP_REG;
687 if ((c->d & ByteOp) && !inhibit_bytereg) {
688 op->ptr = decode_register(reg, c->regs, highbyte_regs);
689 op->val = *(u8 *)op->ptr;
690 op->bytes = 1;
691 } else {
692 op->ptr = decode_register(reg, c->regs, 0);
693 op->bytes = c->op_bytes;
694 switch (op->bytes) {
695 case 2:
696 op->val = *(u16 *)op->ptr;
697 break;
698 case 4:
699 op->val = *(u32 *)op->ptr;
700 break;
701 case 8:
702 op->val = *(u64 *) op->ptr;
703 break;
704 }
705 }
706 op->orig_val = op->val;
707 }
708
709 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
710 struct x86_emulate_ops *ops)
711 {
712 struct decode_cache *c = &ctxt->decode;
713 u8 sib;
714 int index_reg = 0, base_reg = 0, scale;
715 int rc = 0;
716
717 if (c->rex_prefix) {
718 c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */
719 index_reg = (c->rex_prefix & 2) << 2; /* REX.X */
720 c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */
721 }
722
723 c->modrm = insn_fetch(u8, 1, c->eip);
724 c->modrm_mod |= (c->modrm & 0xc0) >> 6;
725 c->modrm_reg |= (c->modrm & 0x38) >> 3;
726 c->modrm_rm |= (c->modrm & 0x07);
727 c->modrm_ea = 0;
728 c->use_modrm_ea = 1;
729
730 if (c->modrm_mod == 3) {
731 c->modrm_ptr = decode_register(c->modrm_rm,
732 c->regs, c->d & ByteOp);
733 c->modrm_val = *(unsigned long *)c->modrm_ptr;
734 return rc;
735 }
736
737 if (c->ad_bytes == 2) {
738 unsigned bx = c->regs[VCPU_REGS_RBX];
739 unsigned bp = c->regs[VCPU_REGS_RBP];
740 unsigned si = c->regs[VCPU_REGS_RSI];
741 unsigned di = c->regs[VCPU_REGS_RDI];
742
743 /* 16-bit ModR/M decode. */
744 switch (c->modrm_mod) {
745 case 0:
746 if (c->modrm_rm == 6)
747 c->modrm_ea += insn_fetch(u16, 2, c->eip);
748 break;
749 case 1:
750 c->modrm_ea += insn_fetch(s8, 1, c->eip);
751 break;
752 case 2:
753 c->modrm_ea += insn_fetch(u16, 2, c->eip);
754 break;
755 }
756 switch (c->modrm_rm) {
757 case 0:
758 c->modrm_ea += bx + si;
759 break;
760 case 1:
761 c->modrm_ea += bx + di;
762 break;
763 case 2:
764 c->modrm_ea += bp + si;
765 break;
766 case 3:
767 c->modrm_ea += bp + di;
768 break;
769 case 4:
770 c->modrm_ea += si;
771 break;
772 case 5:
773 c->modrm_ea += di;
774 break;
775 case 6:
776 if (c->modrm_mod != 0)
777 c->modrm_ea += bp;
778 break;
779 case 7:
780 c->modrm_ea += bx;
781 break;
782 }
783 if (c->modrm_rm == 2 || c->modrm_rm == 3 ||
784 (c->modrm_rm == 6 && c->modrm_mod != 0))
785 if (!c->has_seg_override)
786 set_seg_override(c, VCPU_SREG_SS);
787 c->modrm_ea = (u16)c->modrm_ea;
788 } else {
789 /* 32/64-bit ModR/M decode. */
790 if ((c->modrm_rm & 7) == 4) {
791 sib = insn_fetch(u8, 1, c->eip);
792 index_reg |= (sib >> 3) & 7;
793 base_reg |= sib & 7;
794 scale = sib >> 6;
795
796 if ((base_reg & 7) == 5 && c->modrm_mod == 0)
797 c->modrm_ea += insn_fetch(s32, 4, c->eip);
798 else
799 c->modrm_ea += c->regs[base_reg];
800 if (index_reg != 4)
801 c->modrm_ea += c->regs[index_reg] << scale;
802 } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) {
803 if (ctxt->mode == X86EMUL_MODE_PROT64)
804 c->rip_relative = 1;
805 } else
806 c->modrm_ea += c->regs[c->modrm_rm];
807 switch (c->modrm_mod) {
808 case 0:
809 if (c->modrm_rm == 5)
810 c->modrm_ea += insn_fetch(s32, 4, c->eip);
811 break;
812 case 1:
813 c->modrm_ea += insn_fetch(s8, 1, c->eip);
814 break;
815 case 2:
816 c->modrm_ea += insn_fetch(s32, 4, c->eip);
817 break;
818 }
819 }
820 done:
821 return rc;
822 }
823
824 static int decode_abs(struct x86_emulate_ctxt *ctxt,
825 struct x86_emulate_ops *ops)
826 {
827 struct decode_cache *c = &ctxt->decode;
828 int rc = 0;
829
830 switch (c->ad_bytes) {
831 case 2:
832 c->modrm_ea = insn_fetch(u16, 2, c->eip);
833 break;
834 case 4:
835 c->modrm_ea = insn_fetch(u32, 4, c->eip);
836 break;
837 case 8:
838 c->modrm_ea = insn_fetch(u64, 8, c->eip);
839 break;
840 }
841 done:
842 return rc;
843 }
844
845 int
846 x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
847 {
848 struct decode_cache *c = &ctxt->decode;
849 int rc = 0;
850 int mode = ctxt->mode;
851 int def_op_bytes, def_ad_bytes, group;
852
853 /* Shadow copy of register state. Committed on successful emulation. */
854
855 memset(c, 0, sizeof(struct decode_cache));
856 c->eip = kvm_rip_read(ctxt->vcpu);
857 ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS);
858 memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
859
860 switch (mode) {
861 case X86EMUL_MODE_REAL:
862 case X86EMUL_MODE_PROT16:
863 def_op_bytes = def_ad_bytes = 2;
864 break;
865 case X86EMUL_MODE_PROT32:
866 def_op_bytes = def_ad_bytes = 4;
867 break;
868 #ifdef CONFIG_X86_64
869 case X86EMUL_MODE_PROT64:
870 def_op_bytes = 4;
871 def_ad_bytes = 8;
872 break;
873 #endif
874 default:
875 return -1;
876 }
877
878 c->op_bytes = def_op_bytes;
879 c->ad_bytes = def_ad_bytes;
880
881 /* Legacy prefixes. */
882 for (;;) {
883 switch (c->b = insn_fetch(u8, 1, c->eip)) {
884 case 0x66: /* operand-size override */
885 /* switch between 2/4 bytes */
886 c->op_bytes = def_op_bytes ^ 6;
887 break;
888 case 0x67: /* address-size override */
889 if (mode == X86EMUL_MODE_PROT64)
890 /* switch between 4/8 bytes */
891 c->ad_bytes = def_ad_bytes ^ 12;
892 else
893 /* switch between 2/4 bytes */
894 c->ad_bytes = def_ad_bytes ^ 6;
895 break;
896 case 0x26: /* ES override */
897 case 0x2e: /* CS override */
898 case 0x36: /* SS override */
899 case 0x3e: /* DS override */
900 set_seg_override(c, (c->b >> 3) & 3);
901 break;
902 case 0x64: /* FS override */
903 case 0x65: /* GS override */
904 set_seg_override(c, c->b & 7);
905 break;
906 case 0x40 ... 0x4f: /* REX */
907 if (mode != X86EMUL_MODE_PROT64)
908 goto done_prefixes;
909 c->rex_prefix = c->b;
910 continue;
911 case 0xf0: /* LOCK */
912 c->lock_prefix = 1;
913 break;
914 case 0xf2: /* REPNE/REPNZ */
915 c->rep_prefix = REPNE_PREFIX;
916 break;
917 case 0xf3: /* REP/REPE/REPZ */
918 c->rep_prefix = REPE_PREFIX;
919 break;
920 default:
921 goto done_prefixes;
922 }
923
924 /* Any legacy prefix after a REX prefix nullifies its effect. */
925
926 c->rex_prefix = 0;
927 }
928
929 done_prefixes:
930
931 /* REX prefix. */
932 if (c->rex_prefix)
933 if (c->rex_prefix & 8)
934 c->op_bytes = 8; /* REX.W */
935
936 /* Opcode byte(s). */
937 c->d = opcode_table[c->b];
938 if (c->d == 0) {
939 /* Two-byte opcode? */
940 if (c->b == 0x0f) {
941 c->twobyte = 1;
942 c->b = insn_fetch(u8, 1, c->eip);
943 c->d = twobyte_table[c->b];
944 }
945 }
946
947 if (c->d & Group) {
948 group = c->d & GroupMask;
949 c->modrm = insn_fetch(u8, 1, c->eip);
950 --c->eip;
951
952 group = (group << 3) + ((c->modrm >> 3) & 7);
953 if ((c->d & GroupDual) && (c->modrm >> 6) == 3)
954 c->d = group2_table[group];
955 else
956 c->d = group_table[group];
957 }
958
959 /* Unrecognised? */
960 if (c->d == 0) {
961 DPRINTF("Cannot emulate %02x\n", c->b);
962 return -1;
963 }
964
965 if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack))
966 c->op_bytes = 8;
967
968 /* ModRM and SIB bytes. */
969 if (c->d & ModRM)
970 rc = decode_modrm(ctxt, ops);
971 else if (c->d & MemAbs)
972 rc = decode_abs(ctxt, ops);
973 if (rc)
974 goto done;
975
976 if (!c->has_seg_override)
977 set_seg_override(c, VCPU_SREG_DS);
978
979 if (!(!c->twobyte && c->b == 0x8d))
980 c->modrm_ea += seg_override_base(ctxt, c);
981
982 if (c->ad_bytes != 8)
983 c->modrm_ea = (u32)c->modrm_ea;
984 /*
985 * Decode and fetch the source operand: register, memory
986 * or immediate.
987 */
988 switch (c->d & SrcMask) {
989 case SrcNone:
990 break;
991 case SrcReg:
992 decode_register_operand(&c->src, c, 0);
993 break;
994 case SrcMem16:
995 c->src.bytes = 2;
996 goto srcmem_common;
997 case SrcMem32:
998 c->src.bytes = 4;
999 goto srcmem_common;
1000 case SrcMem:
1001 c->src.bytes = (c->d & ByteOp) ? 1 :
1002 c->op_bytes;
1003 /* Don't fetch the address for invlpg: it could be unmapped. */
1004 if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7)
1005 break;
1006 srcmem_common:
1007 /*
1008 * For instructions with a ModR/M byte, switch to register
1009 * access if Mod = 3.
1010 */
1011 if ((c->d & ModRM) && c->modrm_mod == 3) {
1012 c->src.type = OP_REG;
1013 c->src.val = c->modrm_val;
1014 c->src.ptr = c->modrm_ptr;
1015 break;
1016 }
1017 c->src.type = OP_MEM;
1018 break;
1019 case SrcImm:
1020 c->src.type = OP_IMM;
1021 c->src.ptr = (unsigned long *)c->eip;
1022 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1023 if (c->src.bytes == 8)
1024 c->src.bytes = 4;
1025 /* NB. Immediates are sign-extended as necessary. */
1026 switch (c->src.bytes) {
1027 case 1:
1028 c->src.val = insn_fetch(s8, 1, c->eip);
1029 break;
1030 case 2:
1031 c->src.val = insn_fetch(s16, 2, c->eip);
1032 break;
1033 case 4:
1034 c->src.val = insn_fetch(s32, 4, c->eip);
1035 break;
1036 }
1037 break;
1038 case SrcImmByte:
1039 c->src.type = OP_IMM;
1040 c->src.ptr = (unsigned long *)c->eip;
1041 c->src.bytes = 1;
1042 c->src.val = insn_fetch(s8, 1, c->eip);
1043 break;
1044 }
1045
1046 /* Decode and fetch the destination operand: register or memory. */
1047 switch (c->d & DstMask) {
1048 case ImplicitOps:
1049 /* Special instructions do their own operand decoding. */
1050 return 0;
1051 case DstReg:
1052 decode_register_operand(&c->dst, c,
1053 c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
1054 break;
1055 case DstMem:
1056 if ((c->d & ModRM) && c->modrm_mod == 3) {
1057 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1058 c->dst.type = OP_REG;
1059 c->dst.val = c->dst.orig_val = c->modrm_val;
1060 c->dst.ptr = c->modrm_ptr;
1061 break;
1062 }
1063 c->dst.type = OP_MEM;
1064 break;
1065 case DstAcc:
1066 c->dst.type = OP_REG;
1067 c->dst.bytes = c->op_bytes;
1068 c->dst.ptr = &c->regs[VCPU_REGS_RAX];
1069 switch (c->op_bytes) {
1070 case 1:
1071 c->dst.val = *(u8 *)c->dst.ptr;
1072 break;
1073 case 2:
1074 c->dst.val = *(u16 *)c->dst.ptr;
1075 break;
1076 case 4:
1077 c->dst.val = *(u32 *)c->dst.ptr;
1078 break;
1079 }
1080 c->dst.orig_val = c->dst.val;
1081 break;
1082 }
1083
1084 if (c->rip_relative)
1085 c->modrm_ea += c->eip;
1086
1087 done:
1088 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
1089 }
1090
1091 static inline void emulate_push(struct x86_emulate_ctxt *ctxt)
1092 {
1093 struct decode_cache *c = &ctxt->decode;
1094
1095 c->dst.type = OP_MEM;
1096 c->dst.bytes = c->op_bytes;
1097 c->dst.val = c->src.val;
1098 register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes);
1099 c->dst.ptr = (void *) register_address(c, ss_base(ctxt),
1100 c->regs[VCPU_REGS_RSP]);
1101 }
1102
1103 static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt,
1104 struct x86_emulate_ops *ops)
1105 {
1106 struct decode_cache *c = &ctxt->decode;
1107 int rc;
1108
1109 rc = ops->read_std(register_address(c, ss_base(ctxt),
1110 c->regs[VCPU_REGS_RSP]),
1111 &c->dst.val, c->dst.bytes, ctxt->vcpu);
1112 if (rc != 0)
1113 return rc;
1114
1115 register_address_increment(c, &c->regs[VCPU_REGS_RSP], c->dst.bytes);
1116
1117 return 0;
1118 }
1119
1120 static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt)
1121 {
1122 struct decode_cache *c = &ctxt->decode;
1123 switch (c->modrm_reg) {
1124 case 0: /* rol */
1125 emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags);
1126 break;
1127 case 1: /* ror */
1128 emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags);
1129 break;
1130 case 2: /* rcl */
1131 emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags);
1132 break;
1133 case 3: /* rcr */
1134 emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags);
1135 break;
1136 case 4: /* sal/shl */
1137 case 6: /* sal/shl */
1138 emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags);
1139 break;
1140 case 5: /* shr */
1141 emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags);
1142 break;
1143 case 7: /* sar */
1144 emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags);
1145 break;
1146 }
1147 }
1148
1149 static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
1150 struct x86_emulate_ops *ops)
1151 {
1152 struct decode_cache *c = &ctxt->decode;
1153 int rc = 0;
1154
1155 switch (c->modrm_reg) {
1156 case 0 ... 1: /* test */
1157 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
1158 break;
1159 case 2: /* not */
1160 c->dst.val = ~c->dst.val;
1161 break;
1162 case 3: /* neg */
1163 emulate_1op("neg", c->dst, ctxt->eflags);
1164 break;
1165 default:
1166 DPRINTF("Cannot emulate %02x\n", c->b);
1167 rc = X86EMUL_UNHANDLEABLE;
1168 break;
1169 }
1170 return rc;
1171 }
1172
1173 static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
1174 struct x86_emulate_ops *ops)
1175 {
1176 struct decode_cache *c = &ctxt->decode;
1177
1178 switch (c->modrm_reg) {
1179 case 0: /* inc */
1180 emulate_1op("inc", c->dst, ctxt->eflags);
1181 break;
1182 case 1: /* dec */
1183 emulate_1op("dec", c->dst, ctxt->eflags);
1184 break;
1185 case 2: /* call near abs */ {
1186 long int old_eip;
1187 old_eip = c->eip;
1188 c->eip = c->src.val;
1189 c->src.val = old_eip;
1190 emulate_push(ctxt);
1191 break;
1192 }
1193 case 4: /* jmp abs */
1194 c->eip = c->src.val;
1195 break;
1196 case 6: /* push */
1197 emulate_push(ctxt);
1198 break;
1199 }
1200 return 0;
1201 }
1202
1203 static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
1204 struct x86_emulate_ops *ops,
1205 unsigned long memop)
1206 {
1207 struct decode_cache *c = &ctxt->decode;
1208 u64 old, new;
1209 int rc;
1210
1211 rc = ops->read_emulated(memop, &old, 8, ctxt->vcpu);
1212 if (rc != 0)
1213 return rc;
1214
1215 if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) ||
1216 ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) {
1217
1218 c->regs[VCPU_REGS_RAX] = (u32) (old >> 0);
1219 c->regs[VCPU_REGS_RDX] = (u32) (old >> 32);
1220 ctxt->eflags &= ~EFLG_ZF;
1221
1222 } else {
1223 new = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
1224 (u32) c->regs[VCPU_REGS_RBX];
1225
1226 rc = ops->cmpxchg_emulated(memop, &old, &new, 8, ctxt->vcpu);
1227 if (rc != 0)
1228 return rc;
1229 ctxt->eflags |= EFLG_ZF;
1230 }
1231 return 0;
1232 }
1233
1234 static inline int writeback(struct x86_emulate_ctxt *ctxt,
1235 struct x86_emulate_ops *ops)
1236 {
1237 int rc;
1238 struct decode_cache *c = &ctxt->decode;
1239
1240 switch (c->dst.type) {
1241 case OP_REG:
1242 /* The 4-byte case *is* correct:
1243 * in 64-bit mode we zero-extend.
1244 */
1245 switch (c->dst.bytes) {
1246 case 1:
1247 *(u8 *)c->dst.ptr = (u8)c->dst.val;
1248 break;
1249 case 2:
1250 *(u16 *)c->dst.ptr = (u16)c->dst.val;
1251 break;
1252 case 4:
1253 *c->dst.ptr = (u32)c->dst.val;
1254 break; /* 64b: zero-ext */
1255 case 8:
1256 *c->dst.ptr = c->dst.val;
1257 break;
1258 }
1259 break;
1260 case OP_MEM:
1261 if (c->lock_prefix)
1262 rc = ops->cmpxchg_emulated(
1263 (unsigned long)c->dst.ptr,
1264 &c->dst.orig_val,
1265 &c->dst.val,
1266 c->dst.bytes,
1267 ctxt->vcpu);
1268 else
1269 rc = ops->write_emulated(
1270 (unsigned long)c->dst.ptr,
1271 &c->dst.val,
1272 c->dst.bytes,
1273 ctxt->vcpu);
1274 if (rc != 0)
1275 return rc;
1276 break;
1277 case OP_NONE:
1278 /* no writeback */
1279 break;
1280 default:
1281 break;
1282 }
1283 return 0;
1284 }
1285
1286 int
1287 x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
1288 {
1289 unsigned long memop = 0;
1290 u64 msr_data;
1291 unsigned long saved_eip = 0;
1292 struct decode_cache *c = &ctxt->decode;
1293 unsigned int port;
1294 int io_dir_in;
1295 int rc = 0;
1296
1297 /* Shadow copy of register state. Committed on successful emulation.
1298 * NOTE: we can copy them from vcpu as x86_decode_insn() doesn't
1299 * modify them.
1300 */
1301
1302 memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
1303 saved_eip = c->eip;
1304
1305 if (((c->d & ModRM) && (c->modrm_mod != 3)) || (c->d & MemAbs))
1306 memop = c->modrm_ea;
1307
1308 if (c->rep_prefix && (c->d & String)) {
1309 /* All REP prefixes have the same first termination condition */
1310 if (c->regs[VCPU_REGS_RCX] == 0) {
1311 kvm_rip_write(ctxt->vcpu, c->eip);
1312 goto done;
1313 }
1314 /* The second termination condition only applies for REPE
1315 * and REPNE. Test if the repeat string operation prefix is
1316 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
1317 * corresponding termination condition according to:
1318 * - if REPE/REPZ and ZF = 0 then done
1319 * - if REPNE/REPNZ and ZF = 1 then done
1320 */
1321 if ((c->b == 0xa6) || (c->b == 0xa7) ||
1322 (c->b == 0xae) || (c->b == 0xaf)) {
1323 if ((c->rep_prefix == REPE_PREFIX) &&
1324 ((ctxt->eflags & EFLG_ZF) == 0)) {
1325 kvm_rip_write(ctxt->vcpu, c->eip);
1326 goto done;
1327 }
1328 if ((c->rep_prefix == REPNE_PREFIX) &&
1329 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) {
1330 kvm_rip_write(ctxt->vcpu, c->eip);
1331 goto done;
1332 }
1333 }
1334 c->regs[VCPU_REGS_RCX]--;
1335 c->eip = kvm_rip_read(ctxt->vcpu);
1336 }
1337
1338 if (c->src.type == OP_MEM) {
1339 c->src.ptr = (unsigned long *)memop;
1340 c->src.val = 0;
1341 rc = ops->read_emulated((unsigned long)c->src.ptr,
1342 &c->src.val,
1343 c->src.bytes,
1344 ctxt->vcpu);
1345 if (rc != 0)
1346 goto done;
1347 c->src.orig_val = c->src.val;
1348 }
1349
1350 if ((c->d & DstMask) == ImplicitOps)
1351 goto special_insn;
1352
1353
1354 if (c->dst.type == OP_MEM) {
1355 c->dst.ptr = (unsigned long *)memop;
1356 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1357 c->dst.val = 0;
1358 if (c->d & BitOp) {
1359 unsigned long mask = ~(c->dst.bytes * 8 - 1);
1360
1361 c->dst.ptr = (void *)c->dst.ptr +
1362 (c->src.val & mask) / 8;
1363 }
1364 if (!(c->d & Mov) &&
1365 /* optimisation - avoid slow emulated read */
1366 ((rc = ops->read_emulated((unsigned long)c->dst.ptr,
1367 &c->dst.val,
1368 c->dst.bytes, ctxt->vcpu)) != 0))
1369 goto done;
1370 }
1371 c->dst.orig_val = c->dst.val;
1372
1373 special_insn:
1374
1375 if (c->twobyte)
1376 goto twobyte_insn;
1377
1378 switch (c->b) {
1379 case 0x00 ... 0x05:
1380 add: /* add */
1381 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags);
1382 break;
1383 case 0x08 ... 0x0d:
1384 or: /* or */
1385 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags);
1386 break;
1387 case 0x10 ... 0x15:
1388 adc: /* adc */
1389 emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags);
1390 break;
1391 case 0x18 ... 0x1d:
1392 sbb: /* sbb */
1393 emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags);
1394 break;
1395 case 0x20 ... 0x25:
1396 and: /* and */
1397 emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags);
1398 break;
1399 case 0x28 ... 0x2d:
1400 sub: /* sub */
1401 emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags);
1402 break;
1403 case 0x30 ... 0x35:
1404 xor: /* xor */
1405 emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags);
1406 break;
1407 case 0x38 ... 0x3d:
1408 cmp: /* cmp */
1409 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
1410 break;
1411 case 0x40 ... 0x47: /* inc r16/r32 */
1412 emulate_1op("inc", c->dst, ctxt->eflags);
1413 break;
1414 case 0x48 ... 0x4f: /* dec r16/r32 */
1415 emulate_1op("dec", c->dst, ctxt->eflags);
1416 break;
1417 case 0x50 ... 0x57: /* push reg */
1418 c->dst.type = OP_MEM;
1419 c->dst.bytes = c->op_bytes;
1420 c->dst.val = c->src.val;
1421 register_address_increment(c, &c->regs[VCPU_REGS_RSP],
1422 -c->op_bytes);
1423 c->dst.ptr = (void *) register_address(
1424 c, ss_base(ctxt), c->regs[VCPU_REGS_RSP]);
1425 break;
1426 case 0x58 ... 0x5f: /* pop reg */
1427 pop_instruction:
1428 if ((rc = ops->read_std(register_address(c, ss_base(ctxt),
1429 c->regs[VCPU_REGS_RSP]), c->dst.ptr,
1430 c->op_bytes, ctxt->vcpu)) != 0)
1431 goto done;
1432
1433 register_address_increment(c, &c->regs[VCPU_REGS_RSP],
1434 c->op_bytes);
1435 c->dst.type = OP_NONE; /* Disable writeback. */
1436 break;
1437 case 0x63: /* movsxd */
1438 if (ctxt->mode != X86EMUL_MODE_PROT64)
1439 goto cannot_emulate;
1440 c->dst.val = (s32) c->src.val;
1441 break;
1442 case 0x68: /* push imm */
1443 case 0x6a: /* push imm8 */
1444 emulate_push(ctxt);
1445 break;
1446 case 0x6c: /* insb */
1447 case 0x6d: /* insw/insd */
1448 if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
1449 1,
1450 (c->d & ByteOp) ? 1 : c->op_bytes,
1451 c->rep_prefix ?
1452 address_mask(c, c->regs[VCPU_REGS_RCX]) : 1,
1453 (ctxt->eflags & EFLG_DF),
1454 register_address(c, es_base(ctxt),
1455 c->regs[VCPU_REGS_RDI]),
1456 c->rep_prefix,
1457 c->regs[VCPU_REGS_RDX]) == 0) {
1458 c->eip = saved_eip;
1459 return -1;
1460 }
1461 return 0;
1462 case 0x6e: /* outsb */
1463 case 0x6f: /* outsw/outsd */
1464 if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
1465 0,
1466 (c->d & ByteOp) ? 1 : c->op_bytes,
1467 c->rep_prefix ?
1468 address_mask(c, c->regs[VCPU_REGS_RCX]) : 1,
1469 (ctxt->eflags & EFLG_DF),
1470 register_address(c,
1471 seg_override_base(ctxt, c),
1472 c->regs[VCPU_REGS_RSI]),
1473 c->rep_prefix,
1474 c->regs[VCPU_REGS_RDX]) == 0) {
1475 c->eip = saved_eip;
1476 return -1;
1477 }
1478 return 0;
1479 case 0x70 ... 0x7f: /* jcc (short) */ {
1480 int rel = insn_fetch(s8, 1, c->eip);
1481
1482 if (test_cc(c->b, ctxt->eflags))
1483 jmp_rel(c, rel);
1484 break;
1485 }
1486 case 0x80 ... 0x83: /* Grp1 */
1487 switch (c->modrm_reg) {
1488 case 0:
1489 goto add;
1490 case 1:
1491 goto or;
1492 case 2:
1493 goto adc;
1494 case 3:
1495 goto sbb;
1496 case 4:
1497 goto and;
1498 case 5:
1499 goto sub;
1500 case 6:
1501 goto xor;
1502 case 7:
1503 goto cmp;
1504 }
1505 break;
1506 case 0x84 ... 0x85:
1507 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
1508 break;
1509 case 0x86 ... 0x87: /* xchg */
1510 xchg:
1511 /* Write back the register source. */
1512 switch (c->dst.bytes) {
1513 case 1:
1514 *(u8 *) c->src.ptr = (u8) c->dst.val;
1515 break;
1516 case 2:
1517 *(u16 *) c->src.ptr = (u16) c->dst.val;
1518 break;
1519 case 4:
1520 *c->src.ptr = (u32) c->dst.val;
1521 break; /* 64b reg: zero-extend */
1522 case 8:
1523 *c->src.ptr = c->dst.val;
1524 break;
1525 }
1526 /*
1527 * Write back the memory destination with implicit LOCK
1528 * prefix.
1529 */
1530 c->dst.val = c->src.val;
1531 c->lock_prefix = 1;
1532 break;
1533 case 0x88 ... 0x8b: /* mov */
1534 goto mov;
1535 case 0x8c: { /* mov r/m, sreg */
1536 struct kvm_segment segreg;
1537
1538 if (c->modrm_reg <= 5)
1539 kvm_get_segment(ctxt->vcpu, &segreg, c->modrm_reg);
1540 else {
1541 printk(KERN_INFO "0x8c: Invalid segreg in modrm byte 0x%02x\n",
1542 c->modrm);
1543 goto cannot_emulate;
1544 }
1545 c->dst.val = segreg.selector;
1546 break;
1547 }
1548 case 0x8d: /* lea r16/r32, m */
1549 c->dst.val = c->modrm_ea;
1550 break;
1551 case 0x8e: { /* mov seg, r/m16 */
1552 uint16_t sel;
1553 int type_bits;
1554 int err;
1555
1556 sel = c->src.val;
1557 if (c->modrm_reg <= 5) {
1558 type_bits = (c->modrm_reg == 1) ? 9 : 1;
1559 err = kvm_load_segment_descriptor(ctxt->vcpu, sel,
1560 type_bits, c->modrm_reg);
1561 } else {
1562 printk(KERN_INFO "Invalid segreg in modrm byte 0x%02x\n",
1563 c->modrm);
1564 goto cannot_emulate;
1565 }
1566
1567 if (err < 0)
1568 goto cannot_emulate;
1569
1570 c->dst.type = OP_NONE; /* Disable writeback. */
1571 break;
1572 }
1573 case 0x8f: /* pop (sole member of Grp1a) */
1574 rc = emulate_grp1a(ctxt, ops);
1575 if (rc != 0)
1576 goto done;
1577 break;
1578 case 0x90: /* nop / xchg r8,rax */
1579 if (!(c->rex_prefix & 1)) { /* nop */
1580 c->dst.type = OP_NONE;
1581 break;
1582 }
1583 case 0x91 ... 0x97: /* xchg reg,rax */
1584 c->src.type = c->dst.type = OP_REG;
1585 c->src.bytes = c->dst.bytes = c->op_bytes;
1586 c->src.ptr = (unsigned long *) &c->regs[VCPU_REGS_RAX];
1587 c->src.val = *(c->src.ptr);
1588 goto xchg;
1589 case 0x9c: /* pushf */
1590 c->src.val = (unsigned long) ctxt->eflags;
1591 emulate_push(ctxt);
1592 break;
1593 case 0x9d: /* popf */
1594 c->dst.ptr = (unsigned long *) &ctxt->eflags;
1595 goto pop_instruction;
1596 case 0xa0 ... 0xa1: /* mov */
1597 c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
1598 c->dst.val = c->src.val;
1599 break;
1600 case 0xa2 ... 0xa3: /* mov */
1601 c->dst.val = (unsigned long)c->regs[VCPU_REGS_RAX];
1602 break;
1603 case 0xa4 ... 0xa5: /* movs */
1604 c->dst.type = OP_MEM;
1605 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1606 c->dst.ptr = (unsigned long *)register_address(c,
1607 es_base(ctxt),
1608 c->regs[VCPU_REGS_RDI]);
1609 if ((rc = ops->read_emulated(register_address(c,
1610 seg_override_base(ctxt, c),
1611 c->regs[VCPU_REGS_RSI]),
1612 &c->dst.val,
1613 c->dst.bytes, ctxt->vcpu)) != 0)
1614 goto done;
1615 register_address_increment(c, &c->regs[VCPU_REGS_RSI],
1616 (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
1617 : c->dst.bytes);
1618 register_address_increment(c, &c->regs[VCPU_REGS_RDI],
1619 (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
1620 : c->dst.bytes);
1621 break;
1622 case 0xa6 ... 0xa7: /* cmps */
1623 c->src.type = OP_NONE; /* Disable writeback. */
1624 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1625 c->src.ptr = (unsigned long *)register_address(c,
1626 seg_override_base(ctxt, c),
1627 c->regs[VCPU_REGS_RSI]);
1628 if ((rc = ops->read_emulated((unsigned long)c->src.ptr,
1629 &c->src.val,
1630 c->src.bytes,
1631 ctxt->vcpu)) != 0)
1632 goto done;
1633
1634 c->dst.type = OP_NONE; /* Disable writeback. */
1635 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1636 c->dst.ptr = (unsigned long *)register_address(c,
1637 es_base(ctxt),
1638 c->regs[VCPU_REGS_RDI]);
1639 if ((rc = ops->read_emulated((unsigned long)c->dst.ptr,
1640 &c->dst.val,
1641 c->dst.bytes,
1642 ctxt->vcpu)) != 0)
1643 goto done;
1644
1645 DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr);
1646
1647 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
1648
1649 register_address_increment(c, &c->regs[VCPU_REGS_RSI],
1650 (ctxt->eflags & EFLG_DF) ? -c->src.bytes
1651 : c->src.bytes);
1652 register_address_increment(c, &c->regs[VCPU_REGS_RDI],
1653 (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
1654 : c->dst.bytes);
1655
1656 break;
1657 case 0xaa ... 0xab: /* stos */
1658 c->dst.type = OP_MEM;
1659 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1660 c->dst.ptr = (unsigned long *)register_address(c,
1661 es_base(ctxt),
1662 c->regs[VCPU_REGS_RDI]);
1663 c->dst.val = c->regs[VCPU_REGS_RAX];
1664 register_address_increment(c, &c->regs[VCPU_REGS_RDI],
1665 (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
1666 : c->dst.bytes);
1667 break;
1668 case 0xac ... 0xad: /* lods */
1669 c->dst.type = OP_REG;
1670 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1671 c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
1672 if ((rc = ops->read_emulated(register_address(c,
1673 seg_override_base(ctxt, c),
1674 c->regs[VCPU_REGS_RSI]),
1675 &c->dst.val,
1676 c->dst.bytes,
1677 ctxt->vcpu)) != 0)
1678 goto done;
1679 register_address_increment(c, &c->regs[VCPU_REGS_RSI],
1680 (ctxt->eflags & EFLG_DF) ? -c->dst.bytes
1681 : c->dst.bytes);
1682 break;
1683 case 0xae ... 0xaf: /* scas */
1684 DPRINTF("Urk! I don't handle SCAS.\n");
1685 goto cannot_emulate;
1686 case 0xb0 ... 0xbf: /* mov r, imm */
1687 goto mov;
1688 case 0xc0 ... 0xc1:
1689 emulate_grp2(ctxt);
1690 break;
1691 case 0xc3: /* ret */
1692 c->dst.ptr = &c->eip;
1693 goto pop_instruction;
1694 case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */
1695 mov:
1696 c->dst.val = c->src.val;
1697 break;
1698 case 0xd0 ... 0xd1: /* Grp2 */
1699 c->src.val = 1;
1700 emulate_grp2(ctxt);
1701 break;
1702 case 0xd2 ... 0xd3: /* Grp2 */
1703 c->src.val = c->regs[VCPU_REGS_RCX];
1704 emulate_grp2(ctxt);
1705 break;
1706 case 0xe4: /* inb */
1707 case 0xe5: /* in */
1708 port = insn_fetch(u8, 1, c->eip);
1709 io_dir_in = 1;
1710 goto do_io;
1711 case 0xe6: /* outb */
1712 case 0xe7: /* out */
1713 port = insn_fetch(u8, 1, c->eip);
1714 io_dir_in = 0;
1715 goto do_io;
1716 case 0xe8: /* call (near) */ {
1717 long int rel;
1718 switch (c->op_bytes) {
1719 case 2:
1720 rel = insn_fetch(s16, 2, c->eip);
1721 break;
1722 case 4:
1723 rel = insn_fetch(s32, 4, c->eip);
1724 break;
1725 default:
1726 DPRINTF("Call: Invalid op_bytes\n");
1727 goto cannot_emulate;
1728 }
1729 c->src.val = (unsigned long) c->eip;
1730 jmp_rel(c, rel);
1731 c->op_bytes = c->ad_bytes;
1732 emulate_push(ctxt);
1733 break;
1734 }
1735 case 0xe9: /* jmp rel */
1736 goto jmp;
1737 case 0xea: /* jmp far */ {
1738 uint32_t eip;
1739 uint16_t sel;
1740
1741 switch (c->op_bytes) {
1742 case 2:
1743 eip = insn_fetch(u16, 2, c->eip);
1744 break;
1745 case 4:
1746 eip = insn_fetch(u32, 4, c->eip);
1747 break;
1748 default:
1749 DPRINTF("jmp far: Invalid op_bytes\n");
1750 goto cannot_emulate;
1751 }
1752 sel = insn_fetch(u16, 2, c->eip);
1753 if (kvm_load_segment_descriptor(ctxt->vcpu, sel, 9, VCPU_SREG_CS) < 0) {
1754 DPRINTF("jmp far: Failed to load CS descriptor\n");
1755 goto cannot_emulate;
1756 }
1757
1758 c->eip = eip;
1759 break;
1760 }
1761 case 0xeb:
1762 jmp: /* jmp rel short */
1763 jmp_rel(c, c->src.val);
1764 c->dst.type = OP_NONE; /* Disable writeback. */
1765 break;
1766 case 0xec: /* in al,dx */
1767 case 0xed: /* in (e/r)ax,dx */
1768 port = c->regs[VCPU_REGS_RDX];
1769 io_dir_in = 1;
1770 goto do_io;
1771 case 0xee: /* out al,dx */
1772 case 0xef: /* out (e/r)ax,dx */
1773 port = c->regs[VCPU_REGS_RDX];
1774 io_dir_in = 0;
1775 do_io: if (kvm_emulate_pio(ctxt->vcpu, NULL, io_dir_in,
1776 (c->d & ByteOp) ? 1 : c->op_bytes,
1777 port) != 0) {
1778 c->eip = saved_eip;
1779 goto cannot_emulate;
1780 }
1781 return 0;
1782 case 0xf4: /* hlt */
1783 ctxt->vcpu->arch.halt_request = 1;
1784 break;
1785 case 0xf5: /* cmc */
1786 /* complement carry flag from eflags reg */
1787 ctxt->eflags ^= EFLG_CF;
1788 c->dst.type = OP_NONE; /* Disable writeback. */
1789 break;
1790 case 0xf6 ... 0xf7: /* Grp3 */
1791 rc = emulate_grp3(ctxt, ops);
1792 if (rc != 0)
1793 goto done;
1794 break;
1795 case 0xf8: /* clc */
1796 ctxt->eflags &= ~EFLG_CF;
1797 c->dst.type = OP_NONE; /* Disable writeback. */
1798 break;
1799 case 0xfa: /* cli */
1800 ctxt->eflags &= ~X86_EFLAGS_IF;
1801 c->dst.type = OP_NONE; /* Disable writeback. */
1802 break;
1803 case 0xfb: /* sti */
1804 ctxt->eflags |= X86_EFLAGS_IF;
1805 c->dst.type = OP_NONE; /* Disable writeback. */
1806 break;
1807 case 0xfc: /* cld */
1808 ctxt->eflags &= ~EFLG_DF;
1809 c->dst.type = OP_NONE; /* Disable writeback. */
1810 break;
1811 case 0xfd: /* std */
1812 ctxt->eflags |= EFLG_DF;
1813 c->dst.type = OP_NONE; /* Disable writeback. */
1814 break;
1815 case 0xfe ... 0xff: /* Grp4/Grp5 */
1816 rc = emulate_grp45(ctxt, ops);
1817 if (rc != 0)
1818 goto done;
1819 break;
1820 }
1821
1822 writeback:
1823 rc = writeback(ctxt, ops);
1824 if (rc != 0)
1825 goto done;
1826
1827 /* Commit shadow register state. */
1828 memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
1829 kvm_rip_write(ctxt->vcpu, c->eip);
1830
1831 done:
1832 if (rc == X86EMUL_UNHANDLEABLE) {
1833 c->eip = saved_eip;
1834 return -1;
1835 }
1836 return 0;
1837
1838 twobyte_insn:
1839 switch (c->b) {
1840 case 0x01: /* lgdt, lidt, lmsw */
1841 switch (c->modrm_reg) {
1842 u16 size;
1843 unsigned long address;
1844
1845 case 0: /* vmcall */
1846 if (c->modrm_mod != 3 || c->modrm_rm != 1)
1847 goto cannot_emulate;
1848
1849 rc = kvm_fix_hypercall(ctxt->vcpu);
1850 if (rc)
1851 goto done;
1852
1853 /* Let the processor re-execute the fixed hypercall */
1854 c->eip = kvm_rip_read(ctxt->vcpu);
1855 /* Disable writeback. */
1856 c->dst.type = OP_NONE;
1857 break;
1858 case 2: /* lgdt */
1859 rc = read_descriptor(ctxt, ops, c->src.ptr,
1860 &size, &address, c->op_bytes);
1861 if (rc)
1862 goto done;
1863 realmode_lgdt(ctxt->vcpu, size, address);
1864 /* Disable writeback. */
1865 c->dst.type = OP_NONE;
1866 break;
1867 case 3: /* lidt/vmmcall */
1868 if (c->modrm_mod == 3 && c->modrm_rm == 1) {
1869 rc = kvm_fix_hypercall(ctxt->vcpu);
1870 if (rc)
1871 goto done;
1872 kvm_emulate_hypercall(ctxt->vcpu);
1873 } else {
1874 rc = read_descriptor(ctxt, ops, c->src.ptr,
1875 &size, &address,
1876 c->op_bytes);
1877 if (rc)
1878 goto done;
1879 realmode_lidt(ctxt->vcpu, size, address);
1880 }
1881 /* Disable writeback. */
1882 c->dst.type = OP_NONE;
1883 break;
1884 case 4: /* smsw */
1885 c->dst.bytes = 2;
1886 c->dst.val = realmode_get_cr(ctxt->vcpu, 0);
1887 break;
1888 case 6: /* lmsw */
1889 realmode_lmsw(ctxt->vcpu, (u16)c->src.val,
1890 &ctxt->eflags);
1891 c->dst.type = OP_NONE;
1892 break;
1893 case 7: /* invlpg*/
1894 emulate_invlpg(ctxt->vcpu, memop);
1895 /* Disable writeback. */
1896 c->dst.type = OP_NONE;
1897 break;
1898 default:
1899 goto cannot_emulate;
1900 }
1901 break;
1902 case 0x06:
1903 emulate_clts(ctxt->vcpu);
1904 c->dst.type = OP_NONE;
1905 break;
1906 case 0x08: /* invd */
1907 case 0x09: /* wbinvd */
1908 case 0x0d: /* GrpP (prefetch) */
1909 case 0x18: /* Grp16 (prefetch/nop) */
1910 c->dst.type = OP_NONE;
1911 break;
1912 case 0x20: /* mov cr, reg */
1913 if (c->modrm_mod != 3)
1914 goto cannot_emulate;
1915 c->regs[c->modrm_rm] =
1916 realmode_get_cr(ctxt->vcpu, c->modrm_reg);
1917 c->dst.type = OP_NONE; /* no writeback */
1918 break;
1919 case 0x21: /* mov from dr to reg */
1920 if (c->modrm_mod != 3)
1921 goto cannot_emulate;
1922 rc = emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]);
1923 if (rc)
1924 goto cannot_emulate;
1925 c->dst.type = OP_NONE; /* no writeback */
1926 break;
1927 case 0x22: /* mov reg, cr */
1928 if (c->modrm_mod != 3)
1929 goto cannot_emulate;
1930 realmode_set_cr(ctxt->vcpu,
1931 c->modrm_reg, c->modrm_val, &ctxt->eflags);
1932 c->dst.type = OP_NONE;
1933 break;
1934 case 0x23: /* mov from reg to dr */
1935 if (c->modrm_mod != 3)
1936 goto cannot_emulate;
1937 rc = emulator_set_dr(ctxt, c->modrm_reg,
1938 c->regs[c->modrm_rm]);
1939 if (rc)
1940 goto cannot_emulate;
1941 c->dst.type = OP_NONE; /* no writeback */
1942 break;
1943 case 0x30:
1944 /* wrmsr */
1945 msr_data = (u32)c->regs[VCPU_REGS_RAX]
1946 | ((u64)c->regs[VCPU_REGS_RDX] << 32);
1947 rc = kvm_set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data);
1948 if (rc) {
1949 kvm_inject_gp(ctxt->vcpu, 0);
1950 c->eip = kvm_rip_read(ctxt->vcpu);
1951 }
1952 rc = X86EMUL_CONTINUE;
1953 c->dst.type = OP_NONE;
1954 break;
1955 case 0x32:
1956 /* rdmsr */
1957 rc = kvm_get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data);
1958 if (rc) {
1959 kvm_inject_gp(ctxt->vcpu, 0);
1960 c->eip = kvm_rip_read(ctxt->vcpu);
1961 } else {
1962 c->regs[VCPU_REGS_RAX] = (u32)msr_data;
1963 c->regs[VCPU_REGS_RDX] = msr_data >> 32;
1964 }
1965 rc = X86EMUL_CONTINUE;
1966 c->dst.type = OP_NONE;
1967 break;
1968 case 0x40 ... 0x4f: /* cmov */
1969 c->dst.val = c->dst.orig_val = c->src.val;
1970 if (!test_cc(c->b, ctxt->eflags))
1971 c->dst.type = OP_NONE; /* no writeback */
1972 break;
1973 case 0x80 ... 0x8f: /* jnz rel, etc*/ {
1974 long int rel;
1975
1976 switch (c->op_bytes) {
1977 case 2:
1978 rel = insn_fetch(s16, 2, c->eip);
1979 break;
1980 case 4:
1981 rel = insn_fetch(s32, 4, c->eip);
1982 break;
1983 case 8:
1984 rel = insn_fetch(s64, 8, c->eip);
1985 break;
1986 default:
1987 DPRINTF("jnz: Invalid op_bytes\n");
1988 goto cannot_emulate;
1989 }
1990 if (test_cc(c->b, ctxt->eflags))
1991 jmp_rel(c, rel);
1992 c->dst.type = OP_NONE;
1993 break;
1994 }
1995 case 0xa3:
1996 bt: /* bt */
1997 c->dst.type = OP_NONE;
1998 /* only subword offset */
1999 c->src.val &= (c->dst.bytes << 3) - 1;
2000 emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags);
2001 break;
2002 case 0xab:
2003 bts: /* bts */
2004 /* only subword offset */
2005 c->src.val &= (c->dst.bytes << 3) - 1;
2006 emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags);
2007 break;
2008 case 0xae: /* clflush */
2009 break;
2010 case 0xb0 ... 0xb1: /* cmpxchg */
2011 /*
2012 * Save real source value, then compare EAX against
2013 * destination.
2014 */
2015 c->src.orig_val = c->src.val;
2016 c->src.val = c->regs[VCPU_REGS_RAX];
2017 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
2018 if (ctxt->eflags & EFLG_ZF) {
2019 /* Success: write back to memory. */
2020 c->dst.val = c->src.orig_val;
2021 } else {
2022 /* Failure: write the value we saw to EAX. */
2023 c->dst.type = OP_REG;
2024 c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
2025 }
2026 break;
2027 case 0xb3:
2028 btr: /* btr */
2029 /* only subword offset */
2030 c->src.val &= (c->dst.bytes << 3) - 1;
2031 emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags);
2032 break;
2033 case 0xb6 ... 0xb7: /* movzx */
2034 c->dst.bytes = c->op_bytes;
2035 c->dst.val = (c->d & ByteOp) ? (u8) c->src.val
2036 : (u16) c->src.val;
2037 break;
2038 case 0xba: /* Grp8 */
2039 switch (c->modrm_reg & 3) {
2040 case 0:
2041 goto bt;
2042 case 1:
2043 goto bts;
2044 case 2:
2045 goto btr;
2046 case 3:
2047 goto btc;
2048 }
2049 break;
2050 case 0xbb:
2051 btc: /* btc */
2052 /* only subword offset */
2053 c->src.val &= (c->dst.bytes << 3) - 1;
2054 emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
2055 break;
2056 case 0xbe ... 0xbf: /* movsx */
2057 c->dst.bytes = c->op_bytes;
2058 c->dst.val = (c->d & ByteOp) ? (s8) c->src.val :
2059 (s16) c->src.val;
2060 break;
2061 case 0xc3: /* movnti */
2062 c->dst.bytes = c->op_bytes;
2063 c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val :
2064 (u64) c->src.val;
2065 break;
2066 case 0xc7: /* Grp9 (cmpxchg8b) */
2067 rc = emulate_grp9(ctxt, ops, memop);
2068 if (rc != 0)
2069 goto done;
2070 c->dst.type = OP_NONE;
2071 break;
2072 }
2073 goto writeback;
2074
2075 cannot_emulate:
2076 DPRINTF("Cannot emulate %02x\n", c->b);
2077 c->eip = saved_eip;
2078 return -1;
2079 }
Stable & featurefull patchset based on Linus's git branch