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KVM: x86: Push potential exception error code on task switches
[deliverable/linux.git] / arch / x86 / kvm / emulate.c
1 /******************************************************************************
2 * 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_emulate.h>
34
35 #include "x86.h"
36 #include "tss.h"
37
38 /*
39 * Opcode effective-address decode tables.
40 * Note that we only emulate instructions that have at least one memory
41 * operand (excluding implicit stack references). We assume that stack
42 * references and instruction fetches will never occur in special memory
43 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
44 * not be handled.
45 */
46
47 /* Operand sizes: 8-bit operands or specified/overridden size. */
48 #define ByteOp (1<<0) /* 8-bit operands. */
49 /* Destination operand type. */
50 #define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */
51 #define DstReg (2<<1) /* Register operand. */
52 #define DstMem (3<<1) /* Memory operand. */
53 #define DstAcc (4<<1) /* Destination Accumulator */
54 #define DstDI (5<<1) /* Destination is in ES:(E)DI */
55 #define DstMem64 (6<<1) /* 64bit memory operand */
56 #define DstMask (7<<1)
57 /* Source operand type. */
58 #define SrcNone (0<<4) /* No source operand. */
59 #define SrcImplicit (0<<4) /* Source operand is implicit in the opcode. */
60 #define SrcReg (1<<4) /* Register operand. */
61 #define SrcMem (2<<4) /* Memory operand. */
62 #define SrcMem16 (3<<4) /* Memory operand (16-bit). */
63 #define SrcMem32 (4<<4) /* Memory operand (32-bit). */
64 #define SrcImm (5<<4) /* Immediate operand. */
65 #define SrcImmByte (6<<4) /* 8-bit sign-extended immediate operand. */
66 #define SrcOne (7<<4) /* Implied '1' */
67 #define SrcImmUByte (8<<4) /* 8-bit unsigned immediate operand. */
68 #define SrcImmU (9<<4) /* Immediate operand, unsigned */
69 #define SrcSI (0xa<<4) /* Source is in the DS:RSI */
70 #define SrcMask (0xf<<4)
71 /* Generic ModRM decode. */
72 #define ModRM (1<<8)
73 /* Destination is only written; never read. */
74 #define Mov (1<<9)
75 #define BitOp (1<<10)
76 #define MemAbs (1<<11) /* Memory operand is absolute displacement */
77 #define String (1<<12) /* String instruction (rep capable) */
78 #define Stack (1<<13) /* Stack instruction (push/pop) */
79 #define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */
80 #define GroupDual (1<<15) /* Alternate decoding of mod == 3 */
81 #define GroupMask 0xff /* Group number stored in bits 0:7 */
82 /* Misc flags */
83 #define Lock (1<<26) /* lock prefix is allowed for the instruction */
84 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
85 #define No64 (1<<28)
86 /* Source 2 operand type */
87 #define Src2None (0<<29)
88 #define Src2CL (1<<29)
89 #define Src2ImmByte (2<<29)
90 #define Src2One (3<<29)
91 #define Src2Imm16 (4<<29)
92 #define Src2Mem16 (5<<29) /* Used for Ep encoding. First argument has to be
93 in memory and second argument is located
94 immediately after the first one in memory. */
95 #define Src2Mask (7<<29)
96
97 enum {
98 Group1_80, Group1_81, Group1_82, Group1_83,
99 Group1A, Group3_Byte, Group3, Group4, Group5, Group7,
100 Group8, Group9,
101 };
102
103 static u32 opcode_table[256] = {
104 /* 0x00 - 0x07 */
105 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
106 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
107 ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
108 ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
109 /* 0x08 - 0x0F */
110 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
111 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
112 ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
113 ImplicitOps | Stack | No64, 0,
114 /* 0x10 - 0x17 */
115 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
116 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
117 ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
118 ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
119 /* 0x18 - 0x1F */
120 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
121 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
122 ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
123 ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
124 /* 0x20 - 0x27 */
125 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
126 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
127 DstAcc | SrcImmByte, DstAcc | SrcImm, 0, 0,
128 /* 0x28 - 0x2F */
129 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
130 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
131 0, 0, 0, 0,
132 /* 0x30 - 0x37 */
133 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
134 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
135 0, 0, 0, 0,
136 /* 0x38 - 0x3F */
137 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
138 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
139 ByteOp | DstAcc | SrcImm, DstAcc | SrcImm,
140 0, 0,
141 /* 0x40 - 0x47 */
142 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg,
143 /* 0x48 - 0x4F */
144 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg,
145 /* 0x50 - 0x57 */
146 SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack,
147 SrcReg | Stack, SrcReg | Stack, SrcReg | Stack, SrcReg | Stack,
148 /* 0x58 - 0x5F */
149 DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack,
150 DstReg | Stack, DstReg | Stack, DstReg | Stack, DstReg | Stack,
151 /* 0x60 - 0x67 */
152 ImplicitOps | Stack | No64, ImplicitOps | Stack | No64,
153 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ ,
154 0, 0, 0, 0,
155 /* 0x68 - 0x6F */
156 SrcImm | Mov | Stack, 0, SrcImmByte | Mov | Stack, 0,
157 DstDI | ByteOp | Mov | String, DstDI | Mov | String, /* insb, insw/insd */
158 SrcSI | ByteOp | ImplicitOps | String, SrcSI | ImplicitOps | String, /* outsb, outsw/outsd */
159 /* 0x70 - 0x77 */
160 SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte,
161 SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte,
162 /* 0x78 - 0x7F */
163 SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte,
164 SrcImmByte, SrcImmByte, SrcImmByte, SrcImmByte,
165 /* 0x80 - 0x87 */
166 Group | Group1_80, Group | Group1_81,
167 Group | Group1_82, Group | Group1_83,
168 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
169 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
170 /* 0x88 - 0x8F */
171 ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov,
172 ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
173 DstMem | SrcReg | ModRM | Mov, ModRM | DstReg,
174 DstReg | SrcMem | ModRM | Mov, Group | Group1A,
175 /* 0x90 - 0x97 */
176 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg,
177 /* 0x98 - 0x9F */
178 0, 0, SrcImm | Src2Imm16 | No64, 0,
179 ImplicitOps | Stack, ImplicitOps | Stack, 0, 0,
180 /* 0xA0 - 0xA7 */
181 ByteOp | DstReg | SrcMem | Mov | MemAbs, DstReg | SrcMem | Mov | MemAbs,
182 ByteOp | DstMem | SrcReg | Mov | MemAbs, DstMem | SrcReg | Mov | MemAbs,
183 ByteOp | SrcSI | DstDI | Mov | String, SrcSI | DstDI | Mov | String,
184 ByteOp | SrcSI | DstDI | String, SrcSI | DstDI | String,
185 /* 0xA8 - 0xAF */
186 0, 0, ByteOp | DstDI | Mov | String, DstDI | Mov | String,
187 ByteOp | SrcSI | DstAcc | Mov | String, SrcSI | DstAcc | Mov | String,
188 ByteOp | DstDI | String, DstDI | String,
189 /* 0xB0 - 0xB7 */
190 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
191 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
192 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
193 ByteOp | DstReg | SrcImm | Mov, ByteOp | DstReg | SrcImm | Mov,
194 /* 0xB8 - 0xBF */
195 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
196 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
197 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
198 DstReg | SrcImm | Mov, DstReg | SrcImm | Mov,
199 /* 0xC0 - 0xC7 */
200 ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM,
201 0, ImplicitOps | Stack, 0, 0,
202 ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov,
203 /* 0xC8 - 0xCF */
204 0, 0, 0, ImplicitOps | Stack,
205 ImplicitOps, SrcImmByte, ImplicitOps | No64, ImplicitOps,
206 /* 0xD0 - 0xD7 */
207 ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM,
208 ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM,
209 0, 0, 0, 0,
210 /* 0xD8 - 0xDF */
211 0, 0, 0, 0, 0, 0, 0, 0,
212 /* 0xE0 - 0xE7 */
213 0, 0, 0, 0,
214 ByteOp | SrcImmUByte | DstAcc, SrcImmUByte | DstAcc,
215 ByteOp | SrcImmUByte | DstAcc, SrcImmUByte | DstAcc,
216 /* 0xE8 - 0xEF */
217 SrcImm | Stack, SrcImm | ImplicitOps,
218 SrcImmU | Src2Imm16 | No64, SrcImmByte | ImplicitOps,
219 SrcNone | ByteOp | DstAcc, SrcNone | DstAcc,
220 SrcNone | ByteOp | DstAcc, SrcNone | DstAcc,
221 /* 0xF0 - 0xF7 */
222 0, 0, 0, 0,
223 ImplicitOps | Priv, ImplicitOps, Group | Group3_Byte, Group | Group3,
224 /* 0xF8 - 0xFF */
225 ImplicitOps, 0, ImplicitOps, ImplicitOps,
226 ImplicitOps, ImplicitOps, Group | Group4, Group | Group5,
227 };
228
229 static u32 twobyte_table[256] = {
230 /* 0x00 - 0x0F */
231 0, Group | GroupDual | Group7, 0, 0,
232 0, ImplicitOps, ImplicitOps | Priv, 0,
233 ImplicitOps | Priv, ImplicitOps | Priv, 0, 0,
234 0, ImplicitOps | ModRM, 0, 0,
235 /* 0x10 - 0x1F */
236 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0,
237 /* 0x20 - 0x2F */
238 ModRM | ImplicitOps | Priv, ModRM | Priv,
239 ModRM | ImplicitOps | Priv, ModRM | Priv,
240 0, 0, 0, 0,
241 0, 0, 0, 0, 0, 0, 0, 0,
242 /* 0x30 - 0x3F */
243 ImplicitOps | Priv, 0, ImplicitOps | Priv, 0,
244 ImplicitOps, ImplicitOps | Priv, 0, 0,
245 0, 0, 0, 0, 0, 0, 0, 0,
246 /* 0x40 - 0x47 */
247 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
248 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
249 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
250 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
251 /* 0x48 - 0x4F */
252 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
253 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
254 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
255 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
256 /* 0x50 - 0x5F */
257 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
258 /* 0x60 - 0x6F */
259 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
260 /* 0x70 - 0x7F */
261 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
262 /* 0x80 - 0x8F */
263 SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm,
264 SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm, SrcImm,
265 /* 0x90 - 0x9F */
266 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
267 /* 0xA0 - 0xA7 */
268 ImplicitOps | Stack, ImplicitOps | Stack,
269 0, DstMem | SrcReg | ModRM | BitOp,
270 DstMem | SrcReg | Src2ImmByte | ModRM,
271 DstMem | SrcReg | Src2CL | ModRM, 0, 0,
272 /* 0xA8 - 0xAF */
273 ImplicitOps | Stack, ImplicitOps | Stack,
274 0, DstMem | SrcReg | ModRM | BitOp | Lock,
275 DstMem | SrcReg | Src2ImmByte | ModRM,
276 DstMem | SrcReg | Src2CL | ModRM,
277 ModRM, 0,
278 /* 0xB0 - 0xB7 */
279 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock,
280 0, DstMem | SrcReg | ModRM | BitOp | Lock,
281 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
282 DstReg | SrcMem16 | ModRM | Mov,
283 /* 0xB8 - 0xBF */
284 0, 0,
285 Group | Group8, DstMem | SrcReg | ModRM | BitOp | Lock,
286 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
287 DstReg | SrcMem16 | ModRM | Mov,
288 /* 0xC0 - 0xCF */
289 0, 0, 0, DstMem | SrcReg | ModRM | Mov,
290 0, 0, 0, Group | GroupDual | Group9,
291 0, 0, 0, 0, 0, 0, 0, 0,
292 /* 0xD0 - 0xDF */
293 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
294 /* 0xE0 - 0xEF */
295 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
296 /* 0xF0 - 0xFF */
297 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
298 };
299
300 static u32 group_table[] = {
301 [Group1_80*8] =
302 ByteOp | DstMem | SrcImm | ModRM | Lock,
303 ByteOp | DstMem | SrcImm | ModRM | Lock,
304 ByteOp | DstMem | SrcImm | ModRM | Lock,
305 ByteOp | DstMem | SrcImm | ModRM | Lock,
306 ByteOp | DstMem | SrcImm | ModRM | Lock,
307 ByteOp | DstMem | SrcImm | ModRM | Lock,
308 ByteOp | DstMem | SrcImm | ModRM | Lock,
309 ByteOp | DstMem | SrcImm | ModRM,
310 [Group1_81*8] =
311 DstMem | SrcImm | ModRM | Lock,
312 DstMem | SrcImm | ModRM | Lock,
313 DstMem | SrcImm | ModRM | Lock,
314 DstMem | SrcImm | ModRM | Lock,
315 DstMem | SrcImm | ModRM | Lock,
316 DstMem | SrcImm | ModRM | Lock,
317 DstMem | SrcImm | ModRM | Lock,
318 DstMem | SrcImm | ModRM,
319 [Group1_82*8] =
320 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
321 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
322 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
323 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
324 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
325 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
326 ByteOp | DstMem | SrcImm | ModRM | No64 | Lock,
327 ByteOp | DstMem | SrcImm | ModRM | No64,
328 [Group1_83*8] =
329 DstMem | SrcImmByte | ModRM | Lock,
330 DstMem | SrcImmByte | ModRM | Lock,
331 DstMem | SrcImmByte | ModRM | Lock,
332 DstMem | SrcImmByte | ModRM | Lock,
333 DstMem | SrcImmByte | ModRM | Lock,
334 DstMem | SrcImmByte | ModRM | Lock,
335 DstMem | SrcImmByte | ModRM | Lock,
336 DstMem | SrcImmByte | ModRM,
337 [Group1A*8] =
338 DstMem | SrcNone | ModRM | Mov | Stack, 0, 0, 0, 0, 0, 0, 0,
339 [Group3_Byte*8] =
340 ByteOp | SrcImm | DstMem | ModRM, 0,
341 ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM,
342 0, 0, 0, 0,
343 [Group3*8] =
344 DstMem | SrcImm | ModRM, 0,
345 DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
346 0, 0, 0, 0,
347 [Group4*8] =
348 ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM,
349 0, 0, 0, 0, 0, 0,
350 [Group5*8] =
351 DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
352 SrcMem | ModRM | Stack, 0,
353 SrcMem | ModRM | Stack, SrcMem | ModRM | Src2Mem16 | ImplicitOps,
354 SrcMem | ModRM | Stack, 0,
355 [Group7*8] =
356 0, 0, ModRM | SrcMem | Priv, ModRM | SrcMem | Priv,
357 SrcNone | ModRM | DstMem | Mov, 0,
358 SrcMem16 | ModRM | Mov | Priv, SrcMem | ModRM | ByteOp | Priv,
359 [Group8*8] =
360 0, 0, 0, 0,
361 DstMem | SrcImmByte | ModRM, DstMem | SrcImmByte | ModRM | Lock,
362 DstMem | SrcImmByte | ModRM | Lock, DstMem | SrcImmByte | ModRM | Lock,
363 [Group9*8] =
364 0, DstMem64 | ModRM | Lock, 0, 0, 0, 0, 0, 0,
365 };
366
367 static u32 group2_table[] = {
368 [Group7*8] =
369 SrcNone | ModRM | Priv, 0, 0, SrcNone | ModRM | Priv,
370 SrcNone | ModRM | DstMem | Mov, 0,
371 SrcMem16 | ModRM | Mov | Priv, 0,
372 [Group9*8] =
373 0, 0, 0, 0, 0, 0, 0, 0,
374 };
375
376 /* EFLAGS bit definitions. */
377 #define EFLG_ID (1<<21)
378 #define EFLG_VIP (1<<20)
379 #define EFLG_VIF (1<<19)
380 #define EFLG_AC (1<<18)
381 #define EFLG_VM (1<<17)
382 #define EFLG_RF (1<<16)
383 #define EFLG_IOPL (3<<12)
384 #define EFLG_NT (1<<14)
385 #define EFLG_OF (1<<11)
386 #define EFLG_DF (1<<10)
387 #define EFLG_IF (1<<9)
388 #define EFLG_TF (1<<8)
389 #define EFLG_SF (1<<7)
390 #define EFLG_ZF (1<<6)
391 #define EFLG_AF (1<<4)
392 #define EFLG_PF (1<<2)
393 #define EFLG_CF (1<<0)
394
395 /*
396 * Instruction emulation:
397 * Most instructions are emulated directly via a fragment of inline assembly
398 * code. This allows us to save/restore EFLAGS and thus very easily pick up
399 * any modified flags.
400 */
401
402 #if defined(CONFIG_X86_64)
403 #define _LO32 "k" /* force 32-bit operand */
404 #define _STK "%%rsp" /* stack pointer */
405 #elif defined(__i386__)
406 #define _LO32 "" /* force 32-bit operand */
407 #define _STK "%%esp" /* stack pointer */
408 #endif
409
410 /*
411 * These EFLAGS bits are restored from saved value during emulation, and
412 * any changes are written back to the saved value after emulation.
413 */
414 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
415
416 /* Before executing instruction: restore necessary bits in EFLAGS. */
417 #define _PRE_EFLAGS(_sav, _msk, _tmp) \
418 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \
419 "movl %"_sav",%"_LO32 _tmp"; " \
420 "push %"_tmp"; " \
421 "push %"_tmp"; " \
422 "movl %"_msk",%"_LO32 _tmp"; " \
423 "andl %"_LO32 _tmp",("_STK"); " \
424 "pushf; " \
425 "notl %"_LO32 _tmp"; " \
426 "andl %"_LO32 _tmp",("_STK"); " \
427 "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \
428 "pop %"_tmp"; " \
429 "orl %"_LO32 _tmp",("_STK"); " \
430 "popf; " \
431 "pop %"_sav"; "
432
433 /* After executing instruction: write-back necessary bits in EFLAGS. */
434 #define _POST_EFLAGS(_sav, _msk, _tmp) \
435 /* _sav |= EFLAGS & _msk; */ \
436 "pushf; " \
437 "pop %"_tmp"; " \
438 "andl %"_msk",%"_LO32 _tmp"; " \
439 "orl %"_LO32 _tmp",%"_sav"; "
440
441 #ifdef CONFIG_X86_64
442 #define ON64(x) x
443 #else
444 #define ON64(x)
445 #endif
446
447 #define ____emulate_2op(_op, _src, _dst, _eflags, _x, _y, _suffix) \
448 do { \
449 __asm__ __volatile__ ( \
450 _PRE_EFLAGS("0", "4", "2") \
451 _op _suffix " %"_x"3,%1; " \
452 _POST_EFLAGS("0", "4", "2") \
453 : "=m" (_eflags), "=m" ((_dst).val), \
454 "=&r" (_tmp) \
455 : _y ((_src).val), "i" (EFLAGS_MASK)); \
456 } while (0)
457
458
459 /* Raw emulation: instruction has two explicit operands. */
460 #define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \
461 do { \
462 unsigned long _tmp; \
463 \
464 switch ((_dst).bytes) { \
465 case 2: \
466 ____emulate_2op(_op,_src,_dst,_eflags,_wx,_wy,"w"); \
467 break; \
468 case 4: \
469 ____emulate_2op(_op,_src,_dst,_eflags,_lx,_ly,"l"); \
470 break; \
471 case 8: \
472 ON64(____emulate_2op(_op,_src,_dst,_eflags,_qx,_qy,"q")); \
473 break; \
474 } \
475 } while (0)
476
477 #define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \
478 do { \
479 unsigned long _tmp; \
480 switch ((_dst).bytes) { \
481 case 1: \
482 ____emulate_2op(_op,_src,_dst,_eflags,_bx,_by,"b"); \
483 break; \
484 default: \
485 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
486 _wx, _wy, _lx, _ly, _qx, _qy); \
487 break; \
488 } \
489 } while (0)
490
491 /* Source operand is byte-sized and may be restricted to just %cl. */
492 #define emulate_2op_SrcB(_op, _src, _dst, _eflags) \
493 __emulate_2op(_op, _src, _dst, _eflags, \
494 "b", "c", "b", "c", "b", "c", "b", "c")
495
496 /* Source operand is byte, word, long or quad sized. */
497 #define emulate_2op_SrcV(_op, _src, _dst, _eflags) \
498 __emulate_2op(_op, _src, _dst, _eflags, \
499 "b", "q", "w", "r", _LO32, "r", "", "r")
500
501 /* Source operand is word, long or quad sized. */
502 #define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \
503 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
504 "w", "r", _LO32, "r", "", "r")
505
506 /* Instruction has three operands and one operand is stored in ECX register */
507 #define __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, _suffix, _type) \
508 do { \
509 unsigned long _tmp; \
510 _type _clv = (_cl).val; \
511 _type _srcv = (_src).val; \
512 _type _dstv = (_dst).val; \
513 \
514 __asm__ __volatile__ ( \
515 _PRE_EFLAGS("0", "5", "2") \
516 _op _suffix " %4,%1 \n" \
517 _POST_EFLAGS("0", "5", "2") \
518 : "=m" (_eflags), "+r" (_dstv), "=&r" (_tmp) \
519 : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \
520 ); \
521 \
522 (_cl).val = (unsigned long) _clv; \
523 (_src).val = (unsigned long) _srcv; \
524 (_dst).val = (unsigned long) _dstv; \
525 } while (0)
526
527 #define emulate_2op_cl(_op, _cl, _src, _dst, _eflags) \
528 do { \
529 switch ((_dst).bytes) { \
530 case 2: \
531 __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \
532 "w", unsigned short); \
533 break; \
534 case 4: \
535 __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \
536 "l", unsigned int); \
537 break; \
538 case 8: \
539 ON64(__emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \
540 "q", unsigned long)); \
541 break; \
542 } \
543 } while (0)
544
545 #define __emulate_1op(_op, _dst, _eflags, _suffix) \
546 do { \
547 unsigned long _tmp; \
548 \
549 __asm__ __volatile__ ( \
550 _PRE_EFLAGS("0", "3", "2") \
551 _op _suffix " %1; " \
552 _POST_EFLAGS("0", "3", "2") \
553 : "=m" (_eflags), "+m" ((_dst).val), \
554 "=&r" (_tmp) \
555 : "i" (EFLAGS_MASK)); \
556 } while (0)
557
558 /* Instruction has only one explicit operand (no source operand). */
559 #define emulate_1op(_op, _dst, _eflags) \
560 do { \
561 switch ((_dst).bytes) { \
562 case 1: __emulate_1op(_op, _dst, _eflags, "b"); break; \
563 case 2: __emulate_1op(_op, _dst, _eflags, "w"); break; \
564 case 4: __emulate_1op(_op, _dst, _eflags, "l"); break; \
565 case 8: ON64(__emulate_1op(_op, _dst, _eflags, "q")); break; \
566 } \
567 } while (0)
568
569 /* Fetch next part of the instruction being emulated. */
570 #define insn_fetch(_type, _size, _eip) \
571 ({ unsigned long _x; \
572 rc = do_insn_fetch(ctxt, ops, (_eip), &_x, (_size)); \
573 if (rc != X86EMUL_CONTINUE) \
574 goto done; \
575 (_eip) += (_size); \
576 (_type)_x; \
577 })
578
579 static inline unsigned long ad_mask(struct decode_cache *c)
580 {
581 return (1UL << (c->ad_bytes << 3)) - 1;
582 }
583
584 /* Access/update address held in a register, based on addressing mode. */
585 static inline unsigned long
586 address_mask(struct decode_cache *c, unsigned long reg)
587 {
588 if (c->ad_bytes == sizeof(unsigned long))
589 return reg;
590 else
591 return reg & ad_mask(c);
592 }
593
594 static inline unsigned long
595 register_address(struct decode_cache *c, unsigned long base, unsigned long reg)
596 {
597 return base + address_mask(c, reg);
598 }
599
600 static inline void
601 register_address_increment(struct decode_cache *c, unsigned long *reg, int inc)
602 {
603 if (c->ad_bytes == sizeof(unsigned long))
604 *reg += inc;
605 else
606 *reg = (*reg & ~ad_mask(c)) | ((*reg + inc) & ad_mask(c));
607 }
608
609 static inline void jmp_rel(struct decode_cache *c, int rel)
610 {
611 register_address_increment(c, &c->eip, rel);
612 }
613
614 static void set_seg_override(struct decode_cache *c, int seg)
615 {
616 c->has_seg_override = true;
617 c->seg_override = seg;
618 }
619
620 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
621 {
622 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
623 return 0;
624
625 return kvm_x86_ops->get_segment_base(ctxt->vcpu, seg);
626 }
627
628 static unsigned long seg_override_base(struct x86_emulate_ctxt *ctxt,
629 struct decode_cache *c)
630 {
631 if (!c->has_seg_override)
632 return 0;
633
634 return seg_base(ctxt, c->seg_override);
635 }
636
637 static unsigned long es_base(struct x86_emulate_ctxt *ctxt)
638 {
639 return seg_base(ctxt, VCPU_SREG_ES);
640 }
641
642 static unsigned long ss_base(struct x86_emulate_ctxt *ctxt)
643 {
644 return seg_base(ctxt, VCPU_SREG_SS);
645 }
646
647 static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
648 struct x86_emulate_ops *ops,
649 unsigned long eip, u8 *dest)
650 {
651 struct fetch_cache *fc = &ctxt->decode.fetch;
652 int rc;
653 int size, cur_size;
654
655 if (eip == fc->end) {
656 cur_size = fc->end - fc->start;
657 size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(eip));
658 rc = ops->fetch(ctxt->cs_base + eip, fc->data + cur_size,
659 size, ctxt->vcpu, NULL);
660 if (rc != X86EMUL_CONTINUE)
661 return rc;
662 fc->end += size;
663 }
664 *dest = fc->data[eip - fc->start];
665 return X86EMUL_CONTINUE;
666 }
667
668 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt,
669 struct x86_emulate_ops *ops,
670 unsigned long eip, void *dest, unsigned size)
671 {
672 int rc;
673
674 /* x86 instructions are limited to 15 bytes. */
675 if (eip + size - ctxt->eip > 15)
676 return X86EMUL_UNHANDLEABLE;
677 while (size--) {
678 rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++);
679 if (rc != X86EMUL_CONTINUE)
680 return rc;
681 }
682 return X86EMUL_CONTINUE;
683 }
684
685 /*
686 * Given the 'reg' portion of a ModRM byte, and a register block, return a
687 * pointer into the block that addresses the relevant register.
688 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
689 */
690 static void *decode_register(u8 modrm_reg, unsigned long *regs,
691 int highbyte_regs)
692 {
693 void *p;
694
695 p = &regs[modrm_reg];
696 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
697 p = (unsigned char *)&regs[modrm_reg & 3] + 1;
698 return p;
699 }
700
701 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
702 struct x86_emulate_ops *ops,
703 void *ptr,
704 u16 *size, unsigned long *address, int op_bytes)
705 {
706 int rc;
707
708 if (op_bytes == 2)
709 op_bytes = 3;
710 *address = 0;
711 rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2,
712 ctxt->vcpu, NULL);
713 if (rc != X86EMUL_CONTINUE)
714 return rc;
715 rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes,
716 ctxt->vcpu, NULL);
717 return rc;
718 }
719
720 static int test_cc(unsigned int condition, unsigned int flags)
721 {
722 int rc = 0;
723
724 switch ((condition & 15) >> 1) {
725 case 0: /* o */
726 rc |= (flags & EFLG_OF);
727 break;
728 case 1: /* b/c/nae */
729 rc |= (flags & EFLG_CF);
730 break;
731 case 2: /* z/e */
732 rc |= (flags & EFLG_ZF);
733 break;
734 case 3: /* be/na */
735 rc |= (flags & (EFLG_CF|EFLG_ZF));
736 break;
737 case 4: /* s */
738 rc |= (flags & EFLG_SF);
739 break;
740 case 5: /* p/pe */
741 rc |= (flags & EFLG_PF);
742 break;
743 case 7: /* le/ng */
744 rc |= (flags & EFLG_ZF);
745 /* fall through */
746 case 6: /* l/nge */
747 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
748 break;
749 }
750
751 /* Odd condition identifiers (lsb == 1) have inverted sense. */
752 return (!!rc ^ (condition & 1));
753 }
754
755 static void decode_register_operand(struct operand *op,
756 struct decode_cache *c,
757 int inhibit_bytereg)
758 {
759 unsigned reg = c->modrm_reg;
760 int highbyte_regs = c->rex_prefix == 0;
761
762 if (!(c->d & ModRM))
763 reg = (c->b & 7) | ((c->rex_prefix & 1) << 3);
764 op->type = OP_REG;
765 if ((c->d & ByteOp) && !inhibit_bytereg) {
766 op->ptr = decode_register(reg, c->regs, highbyte_regs);
767 op->val = *(u8 *)op->ptr;
768 op->bytes = 1;
769 } else {
770 op->ptr = decode_register(reg, c->regs, 0);
771 op->bytes = c->op_bytes;
772 switch (op->bytes) {
773 case 2:
774 op->val = *(u16 *)op->ptr;
775 break;
776 case 4:
777 op->val = *(u32 *)op->ptr;
778 break;
779 case 8:
780 op->val = *(u64 *) op->ptr;
781 break;
782 }
783 }
784 op->orig_val = op->val;
785 }
786
787 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
788 struct x86_emulate_ops *ops)
789 {
790 struct decode_cache *c = &ctxt->decode;
791 u8 sib;
792 int index_reg = 0, base_reg = 0, scale;
793 int rc = X86EMUL_CONTINUE;
794
795 if (c->rex_prefix) {
796 c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */
797 index_reg = (c->rex_prefix & 2) << 2; /* REX.X */
798 c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */
799 }
800
801 c->modrm = insn_fetch(u8, 1, c->eip);
802 c->modrm_mod |= (c->modrm & 0xc0) >> 6;
803 c->modrm_reg |= (c->modrm & 0x38) >> 3;
804 c->modrm_rm |= (c->modrm & 0x07);
805 c->modrm_ea = 0;
806 c->use_modrm_ea = 1;
807
808 if (c->modrm_mod == 3) {
809 c->modrm_ptr = decode_register(c->modrm_rm,
810 c->regs, c->d & ByteOp);
811 c->modrm_val = *(unsigned long *)c->modrm_ptr;
812 return rc;
813 }
814
815 if (c->ad_bytes == 2) {
816 unsigned bx = c->regs[VCPU_REGS_RBX];
817 unsigned bp = c->regs[VCPU_REGS_RBP];
818 unsigned si = c->regs[VCPU_REGS_RSI];
819 unsigned di = c->regs[VCPU_REGS_RDI];
820
821 /* 16-bit ModR/M decode. */
822 switch (c->modrm_mod) {
823 case 0:
824 if (c->modrm_rm == 6)
825 c->modrm_ea += insn_fetch(u16, 2, c->eip);
826 break;
827 case 1:
828 c->modrm_ea += insn_fetch(s8, 1, c->eip);
829 break;
830 case 2:
831 c->modrm_ea += insn_fetch(u16, 2, c->eip);
832 break;
833 }
834 switch (c->modrm_rm) {
835 case 0:
836 c->modrm_ea += bx + si;
837 break;
838 case 1:
839 c->modrm_ea += bx + di;
840 break;
841 case 2:
842 c->modrm_ea += bp + si;
843 break;
844 case 3:
845 c->modrm_ea += bp + di;
846 break;
847 case 4:
848 c->modrm_ea += si;
849 break;
850 case 5:
851 c->modrm_ea += di;
852 break;
853 case 6:
854 if (c->modrm_mod != 0)
855 c->modrm_ea += bp;
856 break;
857 case 7:
858 c->modrm_ea += bx;
859 break;
860 }
861 if (c->modrm_rm == 2 || c->modrm_rm == 3 ||
862 (c->modrm_rm == 6 && c->modrm_mod != 0))
863 if (!c->has_seg_override)
864 set_seg_override(c, VCPU_SREG_SS);
865 c->modrm_ea = (u16)c->modrm_ea;
866 } else {
867 /* 32/64-bit ModR/M decode. */
868 if ((c->modrm_rm & 7) == 4) {
869 sib = insn_fetch(u8, 1, c->eip);
870 index_reg |= (sib >> 3) & 7;
871 base_reg |= sib & 7;
872 scale = sib >> 6;
873
874 if ((base_reg & 7) == 5 && c->modrm_mod == 0)
875 c->modrm_ea += insn_fetch(s32, 4, c->eip);
876 else
877 c->modrm_ea += c->regs[base_reg];
878 if (index_reg != 4)
879 c->modrm_ea += c->regs[index_reg] << scale;
880 } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) {
881 if (ctxt->mode == X86EMUL_MODE_PROT64)
882 c->rip_relative = 1;
883 } else
884 c->modrm_ea += c->regs[c->modrm_rm];
885 switch (c->modrm_mod) {
886 case 0:
887 if (c->modrm_rm == 5)
888 c->modrm_ea += insn_fetch(s32, 4, c->eip);
889 break;
890 case 1:
891 c->modrm_ea += insn_fetch(s8, 1, c->eip);
892 break;
893 case 2:
894 c->modrm_ea += insn_fetch(s32, 4, c->eip);
895 break;
896 }
897 }
898 done:
899 return rc;
900 }
901
902 static int decode_abs(struct x86_emulate_ctxt *ctxt,
903 struct x86_emulate_ops *ops)
904 {
905 struct decode_cache *c = &ctxt->decode;
906 int rc = X86EMUL_CONTINUE;
907
908 switch (c->ad_bytes) {
909 case 2:
910 c->modrm_ea = insn_fetch(u16, 2, c->eip);
911 break;
912 case 4:
913 c->modrm_ea = insn_fetch(u32, 4, c->eip);
914 break;
915 case 8:
916 c->modrm_ea = insn_fetch(u64, 8, c->eip);
917 break;
918 }
919 done:
920 return rc;
921 }
922
923 int
924 x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
925 {
926 struct decode_cache *c = &ctxt->decode;
927 int rc = X86EMUL_CONTINUE;
928 int mode = ctxt->mode;
929 int def_op_bytes, def_ad_bytes, group;
930
931
932 /* we cannot decode insn before we complete previous rep insn */
933 WARN_ON(ctxt->restart);
934
935 /* Shadow copy of register state. Committed on successful emulation. */
936 memset(c, 0, sizeof(struct decode_cache));
937 c->eip = ctxt->eip;
938 c->fetch.start = c->fetch.end = c->eip;
939 ctxt->cs_base = seg_base(ctxt, VCPU_SREG_CS);
940 memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
941
942 switch (mode) {
943 case X86EMUL_MODE_REAL:
944 case X86EMUL_MODE_VM86:
945 case X86EMUL_MODE_PROT16:
946 def_op_bytes = def_ad_bytes = 2;
947 break;
948 case X86EMUL_MODE_PROT32:
949 def_op_bytes = def_ad_bytes = 4;
950 break;
951 #ifdef CONFIG_X86_64
952 case X86EMUL_MODE_PROT64:
953 def_op_bytes = 4;
954 def_ad_bytes = 8;
955 break;
956 #endif
957 default:
958 return -1;
959 }
960
961 c->op_bytes = def_op_bytes;
962 c->ad_bytes = def_ad_bytes;
963
964 /* Legacy prefixes. */
965 for (;;) {
966 switch (c->b = insn_fetch(u8, 1, c->eip)) {
967 case 0x66: /* operand-size override */
968 /* switch between 2/4 bytes */
969 c->op_bytes = def_op_bytes ^ 6;
970 break;
971 case 0x67: /* address-size override */
972 if (mode == X86EMUL_MODE_PROT64)
973 /* switch between 4/8 bytes */
974 c->ad_bytes = def_ad_bytes ^ 12;
975 else
976 /* switch between 2/4 bytes */
977 c->ad_bytes = def_ad_bytes ^ 6;
978 break;
979 case 0x26: /* ES override */
980 case 0x2e: /* CS override */
981 case 0x36: /* SS override */
982 case 0x3e: /* DS override */
983 set_seg_override(c, (c->b >> 3) & 3);
984 break;
985 case 0x64: /* FS override */
986 case 0x65: /* GS override */
987 set_seg_override(c, c->b & 7);
988 break;
989 case 0x40 ... 0x4f: /* REX */
990 if (mode != X86EMUL_MODE_PROT64)
991 goto done_prefixes;
992 c->rex_prefix = c->b;
993 continue;
994 case 0xf0: /* LOCK */
995 c->lock_prefix = 1;
996 break;
997 case 0xf2: /* REPNE/REPNZ */
998 c->rep_prefix = REPNE_PREFIX;
999 break;
1000 case 0xf3: /* REP/REPE/REPZ */
1001 c->rep_prefix = REPE_PREFIX;
1002 break;
1003 default:
1004 goto done_prefixes;
1005 }
1006
1007 /* Any legacy prefix after a REX prefix nullifies its effect. */
1008
1009 c->rex_prefix = 0;
1010 }
1011
1012 done_prefixes:
1013
1014 /* REX prefix. */
1015 if (c->rex_prefix)
1016 if (c->rex_prefix & 8)
1017 c->op_bytes = 8; /* REX.W */
1018
1019 /* Opcode byte(s). */
1020 c->d = opcode_table[c->b];
1021 if (c->d == 0) {
1022 /* Two-byte opcode? */
1023 if (c->b == 0x0f) {
1024 c->twobyte = 1;
1025 c->b = insn_fetch(u8, 1, c->eip);
1026 c->d = twobyte_table[c->b];
1027 }
1028 }
1029
1030 if (c->d & Group) {
1031 group = c->d & GroupMask;
1032 c->modrm = insn_fetch(u8, 1, c->eip);
1033 --c->eip;
1034
1035 group = (group << 3) + ((c->modrm >> 3) & 7);
1036 if ((c->d & GroupDual) && (c->modrm >> 6) == 3)
1037 c->d = group2_table[group];
1038 else
1039 c->d = group_table[group];
1040 }
1041
1042 /* Unrecognised? */
1043 if (c->d == 0) {
1044 DPRINTF("Cannot emulate %02x\n", c->b);
1045 return -1;
1046 }
1047
1048 if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack))
1049 c->op_bytes = 8;
1050
1051 /* ModRM and SIB bytes. */
1052 if (c->d & ModRM)
1053 rc = decode_modrm(ctxt, ops);
1054 else if (c->d & MemAbs)
1055 rc = decode_abs(ctxt, ops);
1056 if (rc != X86EMUL_CONTINUE)
1057 goto done;
1058
1059 if (!c->has_seg_override)
1060 set_seg_override(c, VCPU_SREG_DS);
1061
1062 if (!(!c->twobyte && c->b == 0x8d))
1063 c->modrm_ea += seg_override_base(ctxt, c);
1064
1065 if (c->ad_bytes != 8)
1066 c->modrm_ea = (u32)c->modrm_ea;
1067
1068 if (c->rip_relative)
1069 c->modrm_ea += c->eip;
1070
1071 /*
1072 * Decode and fetch the source operand: register, memory
1073 * or immediate.
1074 */
1075 switch (c->d & SrcMask) {
1076 case SrcNone:
1077 break;
1078 case SrcReg:
1079 decode_register_operand(&c->src, c, 0);
1080 break;
1081 case SrcMem16:
1082 c->src.bytes = 2;
1083 goto srcmem_common;
1084 case SrcMem32:
1085 c->src.bytes = 4;
1086 goto srcmem_common;
1087 case SrcMem:
1088 c->src.bytes = (c->d & ByteOp) ? 1 :
1089 c->op_bytes;
1090 /* Don't fetch the address for invlpg: it could be unmapped. */
1091 if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7)
1092 break;
1093 srcmem_common:
1094 /*
1095 * For instructions with a ModR/M byte, switch to register
1096 * access if Mod = 3.
1097 */
1098 if ((c->d & ModRM) && c->modrm_mod == 3) {
1099 c->src.type = OP_REG;
1100 c->src.val = c->modrm_val;
1101 c->src.ptr = c->modrm_ptr;
1102 break;
1103 }
1104 c->src.type = OP_MEM;
1105 c->src.ptr = (unsigned long *)c->modrm_ea;
1106 c->src.val = 0;
1107 break;
1108 case SrcImm:
1109 case SrcImmU:
1110 c->src.type = OP_IMM;
1111 c->src.ptr = (unsigned long *)c->eip;
1112 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1113 if (c->src.bytes == 8)
1114 c->src.bytes = 4;
1115 /* NB. Immediates are sign-extended as necessary. */
1116 switch (c->src.bytes) {
1117 case 1:
1118 c->src.val = insn_fetch(s8, 1, c->eip);
1119 break;
1120 case 2:
1121 c->src.val = insn_fetch(s16, 2, c->eip);
1122 break;
1123 case 4:
1124 c->src.val = insn_fetch(s32, 4, c->eip);
1125 break;
1126 }
1127 if ((c->d & SrcMask) == SrcImmU) {
1128 switch (c->src.bytes) {
1129 case 1:
1130 c->src.val &= 0xff;
1131 break;
1132 case 2:
1133 c->src.val &= 0xffff;
1134 break;
1135 case 4:
1136 c->src.val &= 0xffffffff;
1137 break;
1138 }
1139 }
1140 break;
1141 case SrcImmByte:
1142 case SrcImmUByte:
1143 c->src.type = OP_IMM;
1144 c->src.ptr = (unsigned long *)c->eip;
1145 c->src.bytes = 1;
1146 if ((c->d & SrcMask) == SrcImmByte)
1147 c->src.val = insn_fetch(s8, 1, c->eip);
1148 else
1149 c->src.val = insn_fetch(u8, 1, c->eip);
1150 break;
1151 case SrcOne:
1152 c->src.bytes = 1;
1153 c->src.val = 1;
1154 break;
1155 case SrcSI:
1156 c->src.type = OP_MEM;
1157 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1158 c->src.ptr = (unsigned long *)
1159 register_address(c, seg_override_base(ctxt, c),
1160 c->regs[VCPU_REGS_RSI]);
1161 c->src.val = 0;
1162 break;
1163 }
1164
1165 /*
1166 * Decode and fetch the second source operand: register, memory
1167 * or immediate.
1168 */
1169 switch (c->d & Src2Mask) {
1170 case Src2None:
1171 break;
1172 case Src2CL:
1173 c->src2.bytes = 1;
1174 c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8;
1175 break;
1176 case Src2ImmByte:
1177 c->src2.type = OP_IMM;
1178 c->src2.ptr = (unsigned long *)c->eip;
1179 c->src2.bytes = 1;
1180 c->src2.val = insn_fetch(u8, 1, c->eip);
1181 break;
1182 case Src2Imm16:
1183 c->src2.type = OP_IMM;
1184 c->src2.ptr = (unsigned long *)c->eip;
1185 c->src2.bytes = 2;
1186 c->src2.val = insn_fetch(u16, 2, c->eip);
1187 break;
1188 case Src2One:
1189 c->src2.bytes = 1;
1190 c->src2.val = 1;
1191 break;
1192 case Src2Mem16:
1193 c->src2.type = OP_MEM;
1194 c->src2.bytes = 2;
1195 c->src2.ptr = (unsigned long *)(c->modrm_ea + c->src.bytes);
1196 c->src2.val = 0;
1197 break;
1198 }
1199
1200 /* Decode and fetch the destination operand: register or memory. */
1201 switch (c->d & DstMask) {
1202 case ImplicitOps:
1203 /* Special instructions do their own operand decoding. */
1204 return 0;
1205 case DstReg:
1206 decode_register_operand(&c->dst, c,
1207 c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
1208 break;
1209 case DstMem:
1210 case DstMem64:
1211 if ((c->d & ModRM) && c->modrm_mod == 3) {
1212 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1213 c->dst.type = OP_REG;
1214 c->dst.val = c->dst.orig_val = c->modrm_val;
1215 c->dst.ptr = c->modrm_ptr;
1216 break;
1217 }
1218 c->dst.type = OP_MEM;
1219 c->dst.ptr = (unsigned long *)c->modrm_ea;
1220 if ((c->d & DstMask) == DstMem64)
1221 c->dst.bytes = 8;
1222 else
1223 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1224 c->dst.val = 0;
1225 if (c->d & BitOp) {
1226 unsigned long mask = ~(c->dst.bytes * 8 - 1);
1227
1228 c->dst.ptr = (void *)c->dst.ptr +
1229 (c->src.val & mask) / 8;
1230 }
1231 break;
1232 case DstAcc:
1233 c->dst.type = OP_REG;
1234 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1235 c->dst.ptr = &c->regs[VCPU_REGS_RAX];
1236 switch (c->dst.bytes) {
1237 case 1:
1238 c->dst.val = *(u8 *)c->dst.ptr;
1239 break;
1240 case 2:
1241 c->dst.val = *(u16 *)c->dst.ptr;
1242 break;
1243 case 4:
1244 c->dst.val = *(u32 *)c->dst.ptr;
1245 break;
1246 case 8:
1247 c->dst.val = *(u64 *)c->dst.ptr;
1248 break;
1249 }
1250 c->dst.orig_val = c->dst.val;
1251 break;
1252 case DstDI:
1253 c->dst.type = OP_MEM;
1254 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
1255 c->dst.ptr = (unsigned long *)
1256 register_address(c, es_base(ctxt),
1257 c->regs[VCPU_REGS_RDI]);
1258 c->dst.val = 0;
1259 break;
1260 }
1261
1262 done:
1263 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
1264 }
1265
1266 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
1267 struct x86_emulate_ops *ops,
1268 unsigned int size, unsigned short port,
1269 void *dest)
1270 {
1271 struct read_cache *rc = &ctxt->decode.io_read;
1272
1273 if (rc->pos == rc->end) { /* refill pio read ahead */
1274 struct decode_cache *c = &ctxt->decode;
1275 unsigned int in_page, n;
1276 unsigned int count = c->rep_prefix ?
1277 address_mask(c, c->regs[VCPU_REGS_RCX]) : 1;
1278 in_page = (ctxt->eflags & EFLG_DF) ?
1279 offset_in_page(c->regs[VCPU_REGS_RDI]) :
1280 PAGE_SIZE - offset_in_page(c->regs[VCPU_REGS_RDI]);
1281 n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size,
1282 count);
1283 if (n == 0)
1284 n = 1;
1285 rc->pos = rc->end = 0;
1286 if (!ops->pio_in_emulated(size, port, rc->data, n, ctxt->vcpu))
1287 return 0;
1288 rc->end = n * size;
1289 }
1290
1291 memcpy(dest, rc->data + rc->pos, size);
1292 rc->pos += size;
1293 return 1;
1294 }
1295
1296 static u32 desc_limit_scaled(struct desc_struct *desc)
1297 {
1298 u32 limit = get_desc_limit(desc);
1299
1300 return desc->g ? (limit << 12) | 0xfff : limit;
1301 }
1302
1303 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
1304 struct x86_emulate_ops *ops,
1305 u16 selector, struct desc_ptr *dt)
1306 {
1307 if (selector & 1 << 2) {
1308 struct desc_struct desc;
1309 memset (dt, 0, sizeof *dt);
1310 if (!ops->get_cached_descriptor(&desc, VCPU_SREG_LDTR, ctxt->vcpu))
1311 return;
1312
1313 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
1314 dt->address = get_desc_base(&desc);
1315 } else
1316 ops->get_gdt(dt, ctxt->vcpu);
1317 }
1318
1319 /* allowed just for 8 bytes segments */
1320 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1321 struct x86_emulate_ops *ops,
1322 u16 selector, struct desc_struct *desc)
1323 {
1324 struct desc_ptr dt;
1325 u16 index = selector >> 3;
1326 int ret;
1327 u32 err;
1328 ulong addr;
1329
1330 get_descriptor_table_ptr(ctxt, ops, selector, &dt);
1331
1332 if (dt.size < index * 8 + 7) {
1333 kvm_inject_gp(ctxt->vcpu, selector & 0xfffc);
1334 return X86EMUL_PROPAGATE_FAULT;
1335 }
1336 addr = dt.address + index * 8;
1337 ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu, &err);
1338 if (ret == X86EMUL_PROPAGATE_FAULT)
1339 kvm_inject_page_fault(ctxt->vcpu, addr, err);
1340
1341 return ret;
1342 }
1343
1344 /* allowed just for 8 bytes segments */
1345 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1346 struct x86_emulate_ops *ops,
1347 u16 selector, struct desc_struct *desc)
1348 {
1349 struct desc_ptr dt;
1350 u16 index = selector >> 3;
1351 u32 err;
1352 ulong addr;
1353 int ret;
1354
1355 get_descriptor_table_ptr(ctxt, ops, selector, &dt);
1356
1357 if (dt.size < index * 8 + 7) {
1358 kvm_inject_gp(ctxt->vcpu, selector & 0xfffc);
1359 return X86EMUL_PROPAGATE_FAULT;
1360 }
1361
1362 addr = dt.address + index * 8;
1363 ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu, &err);
1364 if (ret == X86EMUL_PROPAGATE_FAULT)
1365 kvm_inject_page_fault(ctxt->vcpu, addr, err);
1366
1367 return ret;
1368 }
1369
1370 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1371 struct x86_emulate_ops *ops,
1372 u16 selector, int seg)
1373 {
1374 struct desc_struct seg_desc;
1375 u8 dpl, rpl, cpl;
1376 unsigned err_vec = GP_VECTOR;
1377 u32 err_code = 0;
1378 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
1379 int ret;
1380
1381 memset(&seg_desc, 0, sizeof seg_desc);
1382
1383 if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86)
1384 || ctxt->mode == X86EMUL_MODE_REAL) {
1385 /* set real mode segment descriptor */
1386 set_desc_base(&seg_desc, selector << 4);
1387 set_desc_limit(&seg_desc, 0xffff);
1388 seg_desc.type = 3;
1389 seg_desc.p = 1;
1390 seg_desc.s = 1;
1391 goto load;
1392 }
1393
1394 /* NULL selector is not valid for TR, CS and SS */
1395 if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR)
1396 && null_selector)
1397 goto exception;
1398
1399 /* TR should be in GDT only */
1400 if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
1401 goto exception;
1402
1403 if (null_selector) /* for NULL selector skip all following checks */
1404 goto load;
1405
1406 ret = read_segment_descriptor(ctxt, ops, selector, &seg_desc);
1407 if (ret != X86EMUL_CONTINUE)
1408 return ret;
1409
1410 err_code = selector & 0xfffc;
1411 err_vec = GP_VECTOR;
1412
1413 /* can't load system descriptor into segment selecor */
1414 if (seg <= VCPU_SREG_GS && !seg_desc.s)
1415 goto exception;
1416
1417 if (!seg_desc.p) {
1418 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
1419 goto exception;
1420 }
1421
1422 rpl = selector & 3;
1423 dpl = seg_desc.dpl;
1424 cpl = ops->cpl(ctxt->vcpu);
1425
1426 switch (seg) {
1427 case VCPU_SREG_SS:
1428 /*
1429 * segment is not a writable data segment or segment
1430 * selector's RPL != CPL or segment selector's RPL != CPL
1431 */
1432 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
1433 goto exception;
1434 break;
1435 case VCPU_SREG_CS:
1436 if (!(seg_desc.type & 8))
1437 goto exception;
1438
1439 if (seg_desc.type & 4) {
1440 /* conforming */
1441 if (dpl > cpl)
1442 goto exception;
1443 } else {
1444 /* nonconforming */
1445 if (rpl > cpl || dpl != cpl)
1446 goto exception;
1447 }
1448 /* CS(RPL) <- CPL */
1449 selector = (selector & 0xfffc) | cpl;
1450 break;
1451 case VCPU_SREG_TR:
1452 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1453 goto exception;
1454 break;
1455 case VCPU_SREG_LDTR:
1456 if (seg_desc.s || seg_desc.type != 2)
1457 goto exception;
1458 break;
1459 default: /* DS, ES, FS, or GS */
1460 /*
1461 * segment is not a data or readable code segment or
1462 * ((segment is a data or nonconforming code segment)
1463 * and (both RPL and CPL > DPL))
1464 */
1465 if ((seg_desc.type & 0xa) == 0x8 ||
1466 (((seg_desc.type & 0xc) != 0xc) &&
1467 (rpl > dpl && cpl > dpl)))
1468 goto exception;
1469 break;
1470 }
1471
1472 if (seg_desc.s) {
1473 /* mark segment as accessed */
1474 seg_desc.type |= 1;
1475 ret = write_segment_descriptor(ctxt, ops, selector, &seg_desc);
1476 if (ret != X86EMUL_CONTINUE)
1477 return ret;
1478 }
1479 load:
1480 ops->set_segment_selector(selector, seg, ctxt->vcpu);
1481 ops->set_cached_descriptor(&seg_desc, seg, ctxt->vcpu);
1482 return X86EMUL_CONTINUE;
1483 exception:
1484 kvm_queue_exception_e(ctxt->vcpu, err_vec, err_code);
1485 return X86EMUL_PROPAGATE_FAULT;
1486 }
1487
1488 static inline void emulate_push(struct x86_emulate_ctxt *ctxt)
1489 {
1490 struct decode_cache *c = &ctxt->decode;
1491
1492 c->dst.type = OP_MEM;
1493 c->dst.bytes = c->op_bytes;
1494 c->dst.val = c->src.val;
1495 register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes);
1496 c->dst.ptr = (void *) register_address(c, ss_base(ctxt),
1497 c->regs[VCPU_REGS_RSP]);
1498 }
1499
1500 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1501 struct x86_emulate_ops *ops,
1502 void *dest, int len)
1503 {
1504 struct decode_cache *c = &ctxt->decode;
1505 int rc;
1506
1507 rc = ops->read_emulated(register_address(c, ss_base(ctxt),
1508 c->regs[VCPU_REGS_RSP]),
1509 dest, len, ctxt->vcpu);
1510 if (rc != X86EMUL_CONTINUE)
1511 return rc;
1512
1513 register_address_increment(c, &c->regs[VCPU_REGS_RSP], len);
1514 return rc;
1515 }
1516
1517 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1518 struct x86_emulate_ops *ops,
1519 void *dest, int len)
1520 {
1521 int rc;
1522 unsigned long val, change_mask;
1523 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1524 int cpl = ops->cpl(ctxt->vcpu);
1525
1526 rc = emulate_pop(ctxt, ops, &val, len);
1527 if (rc != X86EMUL_CONTINUE)
1528 return rc;
1529
1530 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
1531 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID;
1532
1533 switch(ctxt->mode) {
1534 case X86EMUL_MODE_PROT64:
1535 case X86EMUL_MODE_PROT32:
1536 case X86EMUL_MODE_PROT16:
1537 if (cpl == 0)
1538 change_mask |= EFLG_IOPL;
1539 if (cpl <= iopl)
1540 change_mask |= EFLG_IF;
1541 break;
1542 case X86EMUL_MODE_VM86:
1543 if (iopl < 3) {
1544 kvm_inject_gp(ctxt->vcpu, 0);
1545 return X86EMUL_PROPAGATE_FAULT;
1546 }
1547 change_mask |= EFLG_IF;
1548 break;
1549 default: /* real mode */
1550 change_mask |= (EFLG_IOPL | EFLG_IF);
1551 break;
1552 }
1553
1554 *(unsigned long *)dest =
1555 (ctxt->eflags & ~change_mask) | (val & change_mask);
1556
1557 return rc;
1558 }
1559
1560 static void emulate_push_sreg(struct x86_emulate_ctxt *ctxt, int seg)
1561 {
1562 struct decode_cache *c = &ctxt->decode;
1563 struct kvm_segment segment;
1564
1565 kvm_x86_ops->get_segment(ctxt->vcpu, &segment, seg);
1566
1567 c->src.val = segment.selector;
1568 emulate_push(ctxt);
1569 }
1570
1571 static int emulate_pop_sreg(struct x86_emulate_ctxt *ctxt,
1572 struct x86_emulate_ops *ops, int seg)
1573 {
1574 struct decode_cache *c = &ctxt->decode;
1575 unsigned long selector;
1576 int rc;
1577
1578 rc = emulate_pop(ctxt, ops, &selector, c->op_bytes);
1579 if (rc != X86EMUL_CONTINUE)
1580 return rc;
1581
1582 rc = load_segment_descriptor(ctxt, ops, (u16)selector, seg);
1583 return rc;
1584 }
1585
1586 static void emulate_pusha(struct x86_emulate_ctxt *ctxt)
1587 {
1588 struct decode_cache *c = &ctxt->decode;
1589 unsigned long old_esp = c->regs[VCPU_REGS_RSP];
1590 int reg = VCPU_REGS_RAX;
1591
1592 while (reg <= VCPU_REGS_RDI) {
1593 (reg == VCPU_REGS_RSP) ?
1594 (c->src.val = old_esp) : (c->src.val = c->regs[reg]);
1595
1596 emulate_push(ctxt);
1597 ++reg;
1598 }
1599 }
1600
1601 static int emulate_popa(struct x86_emulate_ctxt *ctxt,
1602 struct x86_emulate_ops *ops)
1603 {
1604 struct decode_cache *c = &ctxt->decode;
1605 int rc = X86EMUL_CONTINUE;
1606 int reg = VCPU_REGS_RDI;
1607
1608 while (reg >= VCPU_REGS_RAX) {
1609 if (reg == VCPU_REGS_RSP) {
1610 register_address_increment(c, &c->regs[VCPU_REGS_RSP],
1611 c->op_bytes);
1612 --reg;
1613 }
1614
1615 rc = emulate_pop(ctxt, ops, &c->regs[reg], c->op_bytes);
1616 if (rc != X86EMUL_CONTINUE)
1617 break;
1618 --reg;
1619 }
1620 return rc;
1621 }
1622
1623 static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt,
1624 struct x86_emulate_ops *ops)
1625 {
1626 struct decode_cache *c = &ctxt->decode;
1627
1628 return emulate_pop(ctxt, ops, &c->dst.val, c->dst.bytes);
1629 }
1630
1631 static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt)
1632 {
1633 struct decode_cache *c = &ctxt->decode;
1634 switch (c->modrm_reg) {
1635 case 0: /* rol */
1636 emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags);
1637 break;
1638 case 1: /* ror */
1639 emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags);
1640 break;
1641 case 2: /* rcl */
1642 emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags);
1643 break;
1644 case 3: /* rcr */
1645 emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags);
1646 break;
1647 case 4: /* sal/shl */
1648 case 6: /* sal/shl */
1649 emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags);
1650 break;
1651 case 5: /* shr */
1652 emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags);
1653 break;
1654 case 7: /* sar */
1655 emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags);
1656 break;
1657 }
1658 }
1659
1660 static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
1661 struct x86_emulate_ops *ops)
1662 {
1663 struct decode_cache *c = &ctxt->decode;
1664
1665 switch (c->modrm_reg) {
1666 case 0 ... 1: /* test */
1667 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
1668 break;
1669 case 2: /* not */
1670 c->dst.val = ~c->dst.val;
1671 break;
1672 case 3: /* neg */
1673 emulate_1op("neg", c->dst, ctxt->eflags);
1674 break;
1675 default:
1676 return 0;
1677 }
1678 return 1;
1679 }
1680
1681 static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
1682 struct x86_emulate_ops *ops)
1683 {
1684 struct decode_cache *c = &ctxt->decode;
1685
1686 switch (c->modrm_reg) {
1687 case 0: /* inc */
1688 emulate_1op("inc", c->dst, ctxt->eflags);
1689 break;
1690 case 1: /* dec */
1691 emulate_1op("dec", c->dst, ctxt->eflags);
1692 break;
1693 case 2: /* call near abs */ {
1694 long int old_eip;
1695 old_eip = c->eip;
1696 c->eip = c->src.val;
1697 c->src.val = old_eip;
1698 emulate_push(ctxt);
1699 break;
1700 }
1701 case 4: /* jmp abs */
1702 c->eip = c->src.val;
1703 break;
1704 case 6: /* push */
1705 emulate_push(ctxt);
1706 break;
1707 }
1708 return X86EMUL_CONTINUE;
1709 }
1710
1711 static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
1712 struct x86_emulate_ops *ops)
1713 {
1714 struct decode_cache *c = &ctxt->decode;
1715 u64 old = c->dst.orig_val;
1716
1717 if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) ||
1718 ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) {
1719
1720 c->regs[VCPU_REGS_RAX] = (u32) (old >> 0);
1721 c->regs[VCPU_REGS_RDX] = (u32) (old >> 32);
1722 ctxt->eflags &= ~EFLG_ZF;
1723 } else {
1724 c->dst.val = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
1725 (u32) c->regs[VCPU_REGS_RBX];
1726
1727 ctxt->eflags |= EFLG_ZF;
1728 }
1729 return X86EMUL_CONTINUE;
1730 }
1731
1732 static int emulate_ret_far(struct x86_emulate_ctxt *ctxt,
1733 struct x86_emulate_ops *ops)
1734 {
1735 struct decode_cache *c = &ctxt->decode;
1736 int rc;
1737 unsigned long cs;
1738
1739 rc = emulate_pop(ctxt, ops, &c->eip, c->op_bytes);
1740 if (rc != X86EMUL_CONTINUE)
1741 return rc;
1742 if (c->op_bytes == 4)
1743 c->eip = (u32)c->eip;
1744 rc = emulate_pop(ctxt, ops, &cs, c->op_bytes);
1745 if (rc != X86EMUL_CONTINUE)
1746 return rc;
1747 rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS);
1748 return rc;
1749 }
1750
1751 static inline int writeback(struct x86_emulate_ctxt *ctxt,
1752 struct x86_emulate_ops *ops)
1753 {
1754 int rc;
1755 struct decode_cache *c = &ctxt->decode;
1756
1757 switch (c->dst.type) {
1758 case OP_REG:
1759 /* The 4-byte case *is* correct:
1760 * in 64-bit mode we zero-extend.
1761 */
1762 switch (c->dst.bytes) {
1763 case 1:
1764 *(u8 *)c->dst.ptr = (u8)c->dst.val;
1765 break;
1766 case 2:
1767 *(u16 *)c->dst.ptr = (u16)c->dst.val;
1768 break;
1769 case 4:
1770 *c->dst.ptr = (u32)c->dst.val;
1771 break; /* 64b: zero-ext */
1772 case 8:
1773 *c->dst.ptr = c->dst.val;
1774 break;
1775 }
1776 break;
1777 case OP_MEM:
1778 if (c->lock_prefix)
1779 rc = ops->cmpxchg_emulated(
1780 (unsigned long)c->dst.ptr,
1781 &c->dst.orig_val,
1782 &c->dst.val,
1783 c->dst.bytes,
1784 ctxt->vcpu);
1785 else
1786 rc = ops->write_emulated(
1787 (unsigned long)c->dst.ptr,
1788 &c->dst.val,
1789 c->dst.bytes,
1790 ctxt->vcpu);
1791 if (rc != X86EMUL_CONTINUE)
1792 return rc;
1793 break;
1794 case OP_NONE:
1795 /* no writeback */
1796 break;
1797 default:
1798 break;
1799 }
1800 return X86EMUL_CONTINUE;
1801 }
1802
1803 static void toggle_interruptibility(struct x86_emulate_ctxt *ctxt, u32 mask)
1804 {
1805 u32 int_shadow = kvm_x86_ops->get_interrupt_shadow(ctxt->vcpu, mask);
1806 /*
1807 * an sti; sti; sequence only disable interrupts for the first
1808 * instruction. So, if the last instruction, be it emulated or
1809 * not, left the system with the INT_STI flag enabled, it
1810 * means that the last instruction is an sti. We should not
1811 * leave the flag on in this case. The same goes for mov ss
1812 */
1813 if (!(int_shadow & mask))
1814 ctxt->interruptibility = mask;
1815 }
1816
1817 static inline void
1818 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
1819 struct kvm_segment *cs, struct kvm_segment *ss)
1820 {
1821 memset(cs, 0, sizeof(struct kvm_segment));
1822 kvm_x86_ops->get_segment(ctxt->vcpu, cs, VCPU_SREG_CS);
1823 memset(ss, 0, sizeof(struct kvm_segment));
1824
1825 cs->l = 0; /* will be adjusted later */
1826 cs->base = 0; /* flat segment */
1827 cs->g = 1; /* 4kb granularity */
1828 cs->limit = 0xffffffff; /* 4GB limit */
1829 cs->type = 0x0b; /* Read, Execute, Accessed */
1830 cs->s = 1;
1831 cs->dpl = 0; /* will be adjusted later */
1832 cs->present = 1;
1833 cs->db = 1;
1834
1835 ss->unusable = 0;
1836 ss->base = 0; /* flat segment */
1837 ss->limit = 0xffffffff; /* 4GB limit */
1838 ss->g = 1; /* 4kb granularity */
1839 ss->s = 1;
1840 ss->type = 0x03; /* Read/Write, Accessed */
1841 ss->db = 1; /* 32bit stack segment */
1842 ss->dpl = 0;
1843 ss->present = 1;
1844 }
1845
1846 static int
1847 emulate_syscall(struct x86_emulate_ctxt *ctxt)
1848 {
1849 struct decode_cache *c = &ctxt->decode;
1850 struct kvm_segment cs, ss;
1851 u64 msr_data;
1852
1853 /* syscall is not available in real mode */
1854 if (ctxt->mode == X86EMUL_MODE_REAL ||
1855 ctxt->mode == X86EMUL_MODE_VM86) {
1856 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
1857 return X86EMUL_PROPAGATE_FAULT;
1858 }
1859
1860 setup_syscalls_segments(ctxt, &cs, &ss);
1861
1862 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data);
1863 msr_data >>= 32;
1864 cs.selector = (u16)(msr_data & 0xfffc);
1865 ss.selector = (u16)(msr_data + 8);
1866
1867 if (is_long_mode(ctxt->vcpu)) {
1868 cs.db = 0;
1869 cs.l = 1;
1870 }
1871 kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS);
1872 kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS);
1873
1874 c->regs[VCPU_REGS_RCX] = c->eip;
1875 if (is_long_mode(ctxt->vcpu)) {
1876 #ifdef CONFIG_X86_64
1877 c->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF;
1878
1879 kvm_x86_ops->get_msr(ctxt->vcpu,
1880 ctxt->mode == X86EMUL_MODE_PROT64 ?
1881 MSR_LSTAR : MSR_CSTAR, &msr_data);
1882 c->eip = msr_data;
1883
1884 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_SYSCALL_MASK, &msr_data);
1885 ctxt->eflags &= ~(msr_data | EFLG_RF);
1886 #endif
1887 } else {
1888 /* legacy mode */
1889 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data);
1890 c->eip = (u32)msr_data;
1891
1892 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1893 }
1894
1895 return X86EMUL_CONTINUE;
1896 }
1897
1898 static int
1899 emulate_sysenter(struct x86_emulate_ctxt *ctxt)
1900 {
1901 struct decode_cache *c = &ctxt->decode;
1902 struct kvm_segment cs, ss;
1903 u64 msr_data;
1904
1905 /* inject #GP if in real mode */
1906 if (ctxt->mode == X86EMUL_MODE_REAL) {
1907 kvm_inject_gp(ctxt->vcpu, 0);
1908 return X86EMUL_PROPAGATE_FAULT;
1909 }
1910
1911 /* XXX sysenter/sysexit have not been tested in 64bit mode.
1912 * Therefore, we inject an #UD.
1913 */
1914 if (ctxt->mode == X86EMUL_MODE_PROT64) {
1915 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
1916 return X86EMUL_PROPAGATE_FAULT;
1917 }
1918
1919 setup_syscalls_segments(ctxt, &cs, &ss);
1920
1921 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data);
1922 switch (ctxt->mode) {
1923 case X86EMUL_MODE_PROT32:
1924 if ((msr_data & 0xfffc) == 0x0) {
1925 kvm_inject_gp(ctxt->vcpu, 0);
1926 return X86EMUL_PROPAGATE_FAULT;
1927 }
1928 break;
1929 case X86EMUL_MODE_PROT64:
1930 if (msr_data == 0x0) {
1931 kvm_inject_gp(ctxt->vcpu, 0);
1932 return X86EMUL_PROPAGATE_FAULT;
1933 }
1934 break;
1935 }
1936
1937 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1938 cs.selector = (u16)msr_data;
1939 cs.selector &= ~SELECTOR_RPL_MASK;
1940 ss.selector = cs.selector + 8;
1941 ss.selector &= ~SELECTOR_RPL_MASK;
1942 if (ctxt->mode == X86EMUL_MODE_PROT64
1943 || is_long_mode(ctxt->vcpu)) {
1944 cs.db = 0;
1945 cs.l = 1;
1946 }
1947
1948 kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS);
1949 kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS);
1950
1951 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_EIP, &msr_data);
1952 c->eip = msr_data;
1953
1954 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_ESP, &msr_data);
1955 c->regs[VCPU_REGS_RSP] = msr_data;
1956
1957 return X86EMUL_CONTINUE;
1958 }
1959
1960 static int
1961 emulate_sysexit(struct x86_emulate_ctxt *ctxt)
1962 {
1963 struct decode_cache *c = &ctxt->decode;
1964 struct kvm_segment cs, ss;
1965 u64 msr_data;
1966 int usermode;
1967
1968 /* inject #GP if in real mode or Virtual 8086 mode */
1969 if (ctxt->mode == X86EMUL_MODE_REAL ||
1970 ctxt->mode == X86EMUL_MODE_VM86) {
1971 kvm_inject_gp(ctxt->vcpu, 0);
1972 return X86EMUL_PROPAGATE_FAULT;
1973 }
1974
1975 setup_syscalls_segments(ctxt, &cs, &ss);
1976
1977 if ((c->rex_prefix & 0x8) != 0x0)
1978 usermode = X86EMUL_MODE_PROT64;
1979 else
1980 usermode = X86EMUL_MODE_PROT32;
1981
1982 cs.dpl = 3;
1983 ss.dpl = 3;
1984 kvm_x86_ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data);
1985 switch (usermode) {
1986 case X86EMUL_MODE_PROT32:
1987 cs.selector = (u16)(msr_data + 16);
1988 if ((msr_data & 0xfffc) == 0x0) {
1989 kvm_inject_gp(ctxt->vcpu, 0);
1990 return X86EMUL_PROPAGATE_FAULT;
1991 }
1992 ss.selector = (u16)(msr_data + 24);
1993 break;
1994 case X86EMUL_MODE_PROT64:
1995 cs.selector = (u16)(msr_data + 32);
1996 if (msr_data == 0x0) {
1997 kvm_inject_gp(ctxt->vcpu, 0);
1998 return X86EMUL_PROPAGATE_FAULT;
1999 }
2000 ss.selector = cs.selector + 8;
2001 cs.db = 0;
2002 cs.l = 1;
2003 break;
2004 }
2005 cs.selector |= SELECTOR_RPL_MASK;
2006 ss.selector |= SELECTOR_RPL_MASK;
2007
2008 kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS);
2009 kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS);
2010
2011 c->eip = ctxt->vcpu->arch.regs[VCPU_REGS_RDX];
2012 c->regs[VCPU_REGS_RSP] = ctxt->vcpu->arch.regs[VCPU_REGS_RCX];
2013
2014 return X86EMUL_CONTINUE;
2015 }
2016
2017 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt,
2018 struct x86_emulate_ops *ops)
2019 {
2020 int iopl;
2021 if (ctxt->mode == X86EMUL_MODE_REAL)
2022 return false;
2023 if (ctxt->mode == X86EMUL_MODE_VM86)
2024 return true;
2025 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
2026 return ops->cpl(ctxt->vcpu) > iopl;
2027 }
2028
2029 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
2030 struct x86_emulate_ops *ops,
2031 u16 port, u16 len)
2032 {
2033 struct kvm_segment tr_seg;
2034 int r;
2035 u16 io_bitmap_ptr;
2036 u8 perm, bit_idx = port & 0x7;
2037 unsigned mask = (1 << len) - 1;
2038
2039 kvm_get_segment(ctxt->vcpu, &tr_seg, VCPU_SREG_TR);
2040 if (tr_seg.unusable)
2041 return false;
2042 if (tr_seg.limit < 103)
2043 return false;
2044 r = ops->read_std(tr_seg.base + 102, &io_bitmap_ptr, 2, ctxt->vcpu,
2045 NULL);
2046 if (r != X86EMUL_CONTINUE)
2047 return false;
2048 if (io_bitmap_ptr + port/8 > tr_seg.limit)
2049 return false;
2050 r = ops->read_std(tr_seg.base + io_bitmap_ptr + port/8, &perm, 1,
2051 ctxt->vcpu, NULL);
2052 if (r != X86EMUL_CONTINUE)
2053 return false;
2054 if ((perm >> bit_idx) & mask)
2055 return false;
2056 return true;
2057 }
2058
2059 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
2060 struct x86_emulate_ops *ops,
2061 u16 port, u16 len)
2062 {
2063 if (emulator_bad_iopl(ctxt, ops))
2064 if (!emulator_io_port_access_allowed(ctxt, ops, port, len))
2065 return false;
2066 return true;
2067 }
2068
2069 static u32 get_cached_descriptor_base(struct x86_emulate_ctxt *ctxt,
2070 struct x86_emulate_ops *ops,
2071 int seg)
2072 {
2073 struct desc_struct desc;
2074 if (ops->get_cached_descriptor(&desc, seg, ctxt->vcpu))
2075 return get_desc_base(&desc);
2076 else
2077 return ~0;
2078 }
2079
2080 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
2081 struct x86_emulate_ops *ops,
2082 struct tss_segment_16 *tss)
2083 {
2084 struct decode_cache *c = &ctxt->decode;
2085
2086 tss->ip = c->eip;
2087 tss->flag = ctxt->eflags;
2088 tss->ax = c->regs[VCPU_REGS_RAX];
2089 tss->cx = c->regs[VCPU_REGS_RCX];
2090 tss->dx = c->regs[VCPU_REGS_RDX];
2091 tss->bx = c->regs[VCPU_REGS_RBX];
2092 tss->sp = c->regs[VCPU_REGS_RSP];
2093 tss->bp = c->regs[VCPU_REGS_RBP];
2094 tss->si = c->regs[VCPU_REGS_RSI];
2095 tss->di = c->regs[VCPU_REGS_RDI];
2096
2097 tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu);
2098 tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);
2099 tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu);
2100 tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu);
2101 tss->ldt = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu);
2102 }
2103
2104 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
2105 struct x86_emulate_ops *ops,
2106 struct tss_segment_16 *tss)
2107 {
2108 struct decode_cache *c = &ctxt->decode;
2109 int ret;
2110
2111 c->eip = tss->ip;
2112 ctxt->eflags = tss->flag | 2;
2113 c->regs[VCPU_REGS_RAX] = tss->ax;
2114 c->regs[VCPU_REGS_RCX] = tss->cx;
2115 c->regs[VCPU_REGS_RDX] = tss->dx;
2116 c->regs[VCPU_REGS_RBX] = tss->bx;
2117 c->regs[VCPU_REGS_RSP] = tss->sp;
2118 c->regs[VCPU_REGS_RBP] = tss->bp;
2119 c->regs[VCPU_REGS_RSI] = tss->si;
2120 c->regs[VCPU_REGS_RDI] = tss->di;
2121
2122 /*
2123 * SDM says that segment selectors are loaded before segment
2124 * descriptors
2125 */
2126 ops->set_segment_selector(tss->ldt, VCPU_SREG_LDTR, ctxt->vcpu);
2127 ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu);
2128 ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu);
2129 ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu);
2130 ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu);
2131
2132 /*
2133 * Now load segment descriptors. If fault happenes at this stage
2134 * it is handled in a context of new task
2135 */
2136 ret = load_segment_descriptor(ctxt, ops, tss->ldt, VCPU_SREG_LDTR);
2137 if (ret != X86EMUL_CONTINUE)
2138 return ret;
2139 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES);
2140 if (ret != X86EMUL_CONTINUE)
2141 return ret;
2142 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS);
2143 if (ret != X86EMUL_CONTINUE)
2144 return ret;
2145 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS);
2146 if (ret != X86EMUL_CONTINUE)
2147 return ret;
2148 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS);
2149 if (ret != X86EMUL_CONTINUE)
2150 return ret;
2151
2152 return X86EMUL_CONTINUE;
2153 }
2154
2155 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
2156 struct x86_emulate_ops *ops,
2157 u16 tss_selector, u16 old_tss_sel,
2158 ulong old_tss_base, struct desc_struct *new_desc)
2159 {
2160 struct tss_segment_16 tss_seg;
2161 int ret;
2162 u32 err, new_tss_base = get_desc_base(new_desc);
2163
2164 ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2165 &err);
2166 if (ret == X86EMUL_PROPAGATE_FAULT) {
2167 /* FIXME: need to provide precise fault address */
2168 kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err);
2169 return ret;
2170 }
2171
2172 save_state_to_tss16(ctxt, ops, &tss_seg);
2173
2174 ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2175 &err);
2176 if (ret == X86EMUL_PROPAGATE_FAULT) {
2177 /* FIXME: need to provide precise fault address */
2178 kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err);
2179 return ret;
2180 }
2181
2182 ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2183 &err);
2184 if (ret == X86EMUL_PROPAGATE_FAULT) {
2185 /* FIXME: need to provide precise fault address */
2186 kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err);
2187 return ret;
2188 }
2189
2190 if (old_tss_sel != 0xffff) {
2191 tss_seg.prev_task_link = old_tss_sel;
2192
2193 ret = ops->write_std(new_tss_base,
2194 &tss_seg.prev_task_link,
2195 sizeof tss_seg.prev_task_link,
2196 ctxt->vcpu, &err);
2197 if (ret == X86EMUL_PROPAGATE_FAULT) {
2198 /* FIXME: need to provide precise fault address */
2199 kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err);
2200 return ret;
2201 }
2202 }
2203
2204 return load_state_from_tss16(ctxt, ops, &tss_seg);
2205 }
2206
2207 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
2208 struct x86_emulate_ops *ops,
2209 struct tss_segment_32 *tss)
2210 {
2211 struct decode_cache *c = &ctxt->decode;
2212
2213 tss->cr3 = ops->get_cr(3, ctxt->vcpu);
2214 tss->eip = c->eip;
2215 tss->eflags = ctxt->eflags;
2216 tss->eax = c->regs[VCPU_REGS_RAX];
2217 tss->ecx = c->regs[VCPU_REGS_RCX];
2218 tss->edx = c->regs[VCPU_REGS_RDX];
2219 tss->ebx = c->regs[VCPU_REGS_RBX];
2220 tss->esp = c->regs[VCPU_REGS_RSP];
2221 tss->ebp = c->regs[VCPU_REGS_RBP];
2222 tss->esi = c->regs[VCPU_REGS_RSI];
2223 tss->edi = c->regs[VCPU_REGS_RDI];
2224
2225 tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu);
2226 tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);
2227 tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu);
2228 tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu);
2229 tss->fs = ops->get_segment_selector(VCPU_SREG_FS, ctxt->vcpu);
2230 tss->gs = ops->get_segment_selector(VCPU_SREG_GS, ctxt->vcpu);
2231 tss->ldt_selector = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu);
2232 }
2233
2234 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
2235 struct x86_emulate_ops *ops,
2236 struct tss_segment_32 *tss)
2237 {
2238 struct decode_cache *c = &ctxt->decode;
2239 int ret;
2240
2241 ops->set_cr(3, tss->cr3, ctxt->vcpu);
2242 c->eip = tss->eip;
2243 ctxt->eflags = tss->eflags | 2;
2244 c->regs[VCPU_REGS_RAX] = tss->eax;
2245 c->regs[VCPU_REGS_RCX] = tss->ecx;
2246 c->regs[VCPU_REGS_RDX] = tss->edx;
2247 c->regs[VCPU_REGS_RBX] = tss->ebx;
2248 c->regs[VCPU_REGS_RSP] = tss->esp;
2249 c->regs[VCPU_REGS_RBP] = tss->ebp;
2250 c->regs[VCPU_REGS_RSI] = tss->esi;
2251 c->regs[VCPU_REGS_RDI] = tss->edi;
2252
2253 /*
2254 * SDM says that segment selectors are loaded before segment
2255 * descriptors
2256 */
2257 ops->set_segment_selector(tss->ldt_selector, VCPU_SREG_LDTR, ctxt->vcpu);
2258 ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu);
2259 ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu);
2260 ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu);
2261 ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu);
2262 ops->set_segment_selector(tss->fs, VCPU_SREG_FS, ctxt->vcpu);
2263 ops->set_segment_selector(tss->gs, VCPU_SREG_GS, ctxt->vcpu);
2264
2265 /*
2266 * Now load segment descriptors. If fault happenes at this stage
2267 * it is handled in a context of new task
2268 */
2269 ret = load_segment_descriptor(ctxt, ops, tss->ldt_selector, VCPU_SREG_LDTR);
2270 if (ret != X86EMUL_CONTINUE)
2271 return ret;
2272 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES);
2273 if (ret != X86EMUL_CONTINUE)
2274 return ret;
2275 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS);
2276 if (ret != X86EMUL_CONTINUE)
2277 return ret;
2278 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS);
2279 if (ret != X86EMUL_CONTINUE)
2280 return ret;
2281 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS);
2282 if (ret != X86EMUL_CONTINUE)
2283 return ret;
2284 ret = load_segment_descriptor(ctxt, ops, tss->fs, VCPU_SREG_FS);
2285 if (ret != X86EMUL_CONTINUE)
2286 return ret;
2287 ret = load_segment_descriptor(ctxt, ops, tss->gs, VCPU_SREG_GS);
2288 if (ret != X86EMUL_CONTINUE)
2289 return ret;
2290
2291 return X86EMUL_CONTINUE;
2292 }
2293
2294 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
2295 struct x86_emulate_ops *ops,
2296 u16 tss_selector, u16 old_tss_sel,
2297 ulong old_tss_base, struct desc_struct *new_desc)
2298 {
2299 struct tss_segment_32 tss_seg;
2300 int ret;
2301 u32 err, new_tss_base = get_desc_base(new_desc);
2302
2303 ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2304 &err);
2305 if (ret == X86EMUL_PROPAGATE_FAULT) {
2306 /* FIXME: need to provide precise fault address */
2307 kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err);
2308 return ret;
2309 }
2310
2311 save_state_to_tss32(ctxt, ops, &tss_seg);
2312
2313 ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2314 &err);
2315 if (ret == X86EMUL_PROPAGATE_FAULT) {
2316 /* FIXME: need to provide precise fault address */
2317 kvm_inject_page_fault(ctxt->vcpu, old_tss_base, err);
2318 return ret;
2319 }
2320
2321 ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2322 &err);
2323 if (ret == X86EMUL_PROPAGATE_FAULT) {
2324 /* FIXME: need to provide precise fault address */
2325 kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err);
2326 return ret;
2327 }
2328
2329 if (old_tss_sel != 0xffff) {
2330 tss_seg.prev_task_link = old_tss_sel;
2331
2332 ret = ops->write_std(new_tss_base,
2333 &tss_seg.prev_task_link,
2334 sizeof tss_seg.prev_task_link,
2335 ctxt->vcpu, &err);
2336 if (ret == X86EMUL_PROPAGATE_FAULT) {
2337 /* FIXME: need to provide precise fault address */
2338 kvm_inject_page_fault(ctxt->vcpu, new_tss_base, err);
2339 return ret;
2340 }
2341 }
2342
2343 return load_state_from_tss32(ctxt, ops, &tss_seg);
2344 }
2345
2346 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
2347 struct x86_emulate_ops *ops,
2348 u16 tss_selector, int reason,
2349 bool has_error_code, u32 error_code)
2350 {
2351 struct desc_struct curr_tss_desc, next_tss_desc;
2352 int ret;
2353 u16 old_tss_sel = ops->get_segment_selector(VCPU_SREG_TR, ctxt->vcpu);
2354 ulong old_tss_base =
2355 get_cached_descriptor_base(ctxt, ops, VCPU_SREG_TR);
2356 u32 desc_limit;
2357
2358 /* FIXME: old_tss_base == ~0 ? */
2359
2360 ret = read_segment_descriptor(ctxt, ops, tss_selector, &next_tss_desc);
2361 if (ret != X86EMUL_CONTINUE)
2362 return ret;
2363 ret = read_segment_descriptor(ctxt, ops, old_tss_sel, &curr_tss_desc);
2364 if (ret != X86EMUL_CONTINUE)
2365 return ret;
2366
2367 /* FIXME: check that next_tss_desc is tss */
2368
2369 if (reason != TASK_SWITCH_IRET) {
2370 if ((tss_selector & 3) > next_tss_desc.dpl ||
2371 ops->cpl(ctxt->vcpu) > next_tss_desc.dpl) {
2372 kvm_inject_gp(ctxt->vcpu, 0);
2373 return X86EMUL_PROPAGATE_FAULT;
2374 }
2375 }
2376
2377 desc_limit = desc_limit_scaled(&next_tss_desc);
2378 if (!next_tss_desc.p ||
2379 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
2380 desc_limit < 0x2b)) {
2381 kvm_queue_exception_e(ctxt->vcpu, TS_VECTOR,
2382 tss_selector & 0xfffc);
2383 return X86EMUL_PROPAGATE_FAULT;
2384 }
2385
2386 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
2387 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
2388 write_segment_descriptor(ctxt, ops, old_tss_sel,
2389 &curr_tss_desc);
2390 }
2391
2392 if (reason == TASK_SWITCH_IRET)
2393 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
2394
2395 /* set back link to prev task only if NT bit is set in eflags
2396 note that old_tss_sel is not used afetr this point */
2397 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
2398 old_tss_sel = 0xffff;
2399
2400 if (next_tss_desc.type & 8)
2401 ret = task_switch_32(ctxt, ops, tss_selector, old_tss_sel,
2402 old_tss_base, &next_tss_desc);
2403 else
2404 ret = task_switch_16(ctxt, ops, tss_selector, old_tss_sel,
2405 old_tss_base, &next_tss_desc);
2406 if (ret != X86EMUL_CONTINUE)
2407 return ret;
2408
2409 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
2410 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
2411
2412 if (reason != TASK_SWITCH_IRET) {
2413 next_tss_desc.type |= (1 << 1); /* set busy flag */
2414 write_segment_descriptor(ctxt, ops, tss_selector,
2415 &next_tss_desc);
2416 }
2417
2418 ops->set_cr(0, ops->get_cr(0, ctxt->vcpu) | X86_CR0_TS, ctxt->vcpu);
2419 ops->set_cached_descriptor(&next_tss_desc, VCPU_SREG_TR, ctxt->vcpu);
2420 ops->set_segment_selector(tss_selector, VCPU_SREG_TR, ctxt->vcpu);
2421
2422 if (has_error_code) {
2423 struct decode_cache *c = &ctxt->decode;
2424
2425 c->op_bytes = c->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
2426 c->lock_prefix = 0;
2427 c->src.val = (unsigned long) error_code;
2428 emulate_push(ctxt);
2429 }
2430
2431 return ret;
2432 }
2433
2434 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
2435 struct x86_emulate_ops *ops,
2436 u16 tss_selector, int reason,
2437 bool has_error_code, u32 error_code)
2438 {
2439 struct decode_cache *c = &ctxt->decode;
2440 int rc;
2441
2442 memset(c, 0, sizeof(struct decode_cache));
2443 c->eip = ctxt->eip;
2444 memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
2445 c->dst.type = OP_NONE;
2446
2447 rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason,
2448 has_error_code, error_code);
2449
2450 if (rc == X86EMUL_CONTINUE) {
2451 memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
2452 kvm_rip_write(ctxt->vcpu, c->eip);
2453 rc = writeback(ctxt, ops);
2454 }
2455
2456 return rc;
2457 }
2458
2459 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned long base,
2460 int reg, struct operand *op)
2461 {
2462 struct decode_cache *c = &ctxt->decode;
2463 int df = (ctxt->eflags & EFLG_DF) ? -1 : 1;
2464
2465 register_address_increment(c, &c->regs[reg], df * op->bytes);
2466 op->ptr = (unsigned long *)register_address(c, base, c->regs[reg]);
2467 }
2468
2469 int
2470 x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
2471 {
2472 u64 msr_data;
2473 struct decode_cache *c = &ctxt->decode;
2474 int rc = X86EMUL_CONTINUE;
2475 int saved_dst_type = c->dst.type;
2476
2477 ctxt->interruptibility = 0;
2478
2479 /* Shadow copy of register state. Committed on successful emulation.
2480 * NOTE: we can copy them from vcpu as x86_decode_insn() doesn't
2481 * modify them.
2482 */
2483
2484 memcpy(c->regs, ctxt->vcpu->arch.regs, sizeof c->regs);
2485
2486 if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
2487 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
2488 goto done;
2489 }
2490
2491 /* LOCK prefix is allowed only with some instructions */
2492 if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {
2493 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
2494 goto done;
2495 }
2496
2497 /* Privileged instruction can be executed only in CPL=0 */
2498 if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) {
2499 kvm_inject_gp(ctxt->vcpu, 0);
2500 goto done;
2501 }
2502
2503 if (c->rep_prefix && (c->d & String)) {
2504 ctxt->restart = true;
2505 /* All REP prefixes have the same first termination condition */
2506 if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) {
2507 string_done:
2508 ctxt->restart = false;
2509 kvm_rip_write(ctxt->vcpu, c->eip);
2510 goto done;
2511 }
2512 /* The second termination condition only applies for REPE
2513 * and REPNE. Test if the repeat string operation prefix is
2514 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
2515 * corresponding termination condition according to:
2516 * - if REPE/REPZ and ZF = 0 then done
2517 * - if REPNE/REPNZ and ZF = 1 then done
2518 */
2519 if ((c->b == 0xa6) || (c->b == 0xa7) ||
2520 (c->b == 0xae) || (c->b == 0xaf)) {
2521 if ((c->rep_prefix == REPE_PREFIX) &&
2522 ((ctxt->eflags & EFLG_ZF) == 0))
2523 goto string_done;
2524 if ((c->rep_prefix == REPNE_PREFIX) &&
2525 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))
2526 goto string_done;
2527 }
2528 c->eip = ctxt->eip;
2529 }
2530
2531 if (c->src.type == OP_MEM) {
2532 rc = ops->read_emulated((unsigned long)c->src.ptr,
2533 &c->src.val,
2534 c->src.bytes,
2535 ctxt->vcpu);
2536 if (rc != X86EMUL_CONTINUE)
2537 goto done;
2538 c->src.orig_val = c->src.val;
2539 }
2540
2541 if (c->src2.type == OP_MEM) {
2542 rc = ops->read_emulated((unsigned long)c->src2.ptr,
2543 &c->src2.val,
2544 c->src2.bytes,
2545 ctxt->vcpu);
2546 if (rc != X86EMUL_CONTINUE)
2547 goto done;
2548 }
2549
2550 if ((c->d & DstMask) == ImplicitOps)
2551 goto special_insn;
2552
2553
2554 if ((c->dst.type == OP_MEM) && !(c->d & Mov)) {
2555 /* optimisation - avoid slow emulated read if Mov */
2556 rc = ops->read_emulated((unsigned long)c->dst.ptr, &c->dst.val,
2557 c->dst.bytes, ctxt->vcpu);
2558 if (rc != X86EMUL_CONTINUE)
2559 goto done;
2560 }
2561 c->dst.orig_val = c->dst.val;
2562
2563 special_insn:
2564
2565 if (c->twobyte)
2566 goto twobyte_insn;
2567
2568 switch (c->b) {
2569 case 0x00 ... 0x05:
2570 add: /* add */
2571 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags);
2572 break;
2573 case 0x06: /* push es */
2574 emulate_push_sreg(ctxt, VCPU_SREG_ES);
2575 break;
2576 case 0x07: /* pop es */
2577 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_ES);
2578 if (rc != X86EMUL_CONTINUE)
2579 goto done;
2580 break;
2581 case 0x08 ... 0x0d:
2582 or: /* or */
2583 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags);
2584 break;
2585 case 0x0e: /* push cs */
2586 emulate_push_sreg(ctxt, VCPU_SREG_CS);
2587 break;
2588 case 0x10 ... 0x15:
2589 adc: /* adc */
2590 emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags);
2591 break;
2592 case 0x16: /* push ss */
2593 emulate_push_sreg(ctxt, VCPU_SREG_SS);
2594 break;
2595 case 0x17: /* pop ss */
2596 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_SS);
2597 if (rc != X86EMUL_CONTINUE)
2598 goto done;
2599 break;
2600 case 0x18 ... 0x1d:
2601 sbb: /* sbb */
2602 emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags);
2603 break;
2604 case 0x1e: /* push ds */
2605 emulate_push_sreg(ctxt, VCPU_SREG_DS);
2606 break;
2607 case 0x1f: /* pop ds */
2608 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_DS);
2609 if (rc != X86EMUL_CONTINUE)
2610 goto done;
2611 break;
2612 case 0x20 ... 0x25:
2613 and: /* and */
2614 emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags);
2615 break;
2616 case 0x28 ... 0x2d:
2617 sub: /* sub */
2618 emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags);
2619 break;
2620 case 0x30 ... 0x35:
2621 xor: /* xor */
2622 emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags);
2623 break;
2624 case 0x38 ... 0x3d:
2625 cmp: /* cmp */
2626 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
2627 break;
2628 case 0x40 ... 0x47: /* inc r16/r32 */
2629 emulate_1op("inc", c->dst, ctxt->eflags);
2630 break;
2631 case 0x48 ... 0x4f: /* dec r16/r32 */
2632 emulate_1op("dec", c->dst, ctxt->eflags);
2633 break;
2634 case 0x50 ... 0x57: /* push reg */
2635 emulate_push(ctxt);
2636 break;
2637 case 0x58 ... 0x5f: /* pop reg */
2638 pop_instruction:
2639 rc = emulate_pop(ctxt, ops, &c->dst.val, c->op_bytes);
2640 if (rc != X86EMUL_CONTINUE)
2641 goto done;
2642 break;
2643 case 0x60: /* pusha */
2644 emulate_pusha(ctxt);
2645 break;
2646 case 0x61: /* popa */
2647 rc = emulate_popa(ctxt, ops);
2648 if (rc != X86EMUL_CONTINUE)
2649 goto done;
2650 break;
2651 case 0x63: /* movsxd */
2652 if (ctxt->mode != X86EMUL_MODE_PROT64)
2653 goto cannot_emulate;
2654 c->dst.val = (s32) c->src.val;
2655 break;
2656 case 0x68: /* push imm */
2657 case 0x6a: /* push imm8 */
2658 emulate_push(ctxt);
2659 break;
2660 case 0x6c: /* insb */
2661 case 0x6d: /* insw/insd */
2662 c->dst.bytes = min(c->dst.bytes, 4u);
2663 if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX],
2664 c->dst.bytes)) {
2665 kvm_inject_gp(ctxt->vcpu, 0);
2666 goto done;
2667 }
2668 if (!pio_in_emulated(ctxt, ops, c->dst.bytes,
2669 c->regs[VCPU_REGS_RDX], &c->dst.val))
2670 goto done; /* IO is needed, skip writeback */
2671 break;
2672 case 0x6e: /* outsb */
2673 case 0x6f: /* outsw/outsd */
2674 c->src.bytes = min(c->src.bytes, 4u);
2675 if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX],
2676 c->src.bytes)) {
2677 kvm_inject_gp(ctxt->vcpu, 0);
2678 goto done;
2679 }
2680 ops->pio_out_emulated(c->src.bytes, c->regs[VCPU_REGS_RDX],
2681 &c->src.val, 1, ctxt->vcpu);
2682
2683 c->dst.type = OP_NONE; /* nothing to writeback */
2684 break;
2685 case 0x70 ... 0x7f: /* jcc (short) */
2686 if (test_cc(c->b, ctxt->eflags))
2687 jmp_rel(c, c->src.val);
2688 break;
2689 case 0x80 ... 0x83: /* Grp1 */
2690 switch (c->modrm_reg) {
2691 case 0:
2692 goto add;
2693 case 1:
2694 goto or;
2695 case 2:
2696 goto adc;
2697 case 3:
2698 goto sbb;
2699 case 4:
2700 goto and;
2701 case 5:
2702 goto sub;
2703 case 6:
2704 goto xor;
2705 case 7:
2706 goto cmp;
2707 }
2708 break;
2709 case 0x84 ... 0x85:
2710 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
2711 break;
2712 case 0x86 ... 0x87: /* xchg */
2713 xchg:
2714 /* Write back the register source. */
2715 switch (c->dst.bytes) {
2716 case 1:
2717 *(u8 *) c->src.ptr = (u8) c->dst.val;
2718 break;
2719 case 2:
2720 *(u16 *) c->src.ptr = (u16) c->dst.val;
2721 break;
2722 case 4:
2723 *c->src.ptr = (u32) c->dst.val;
2724 break; /* 64b reg: zero-extend */
2725 case 8:
2726 *c->src.ptr = c->dst.val;
2727 break;
2728 }
2729 /*
2730 * Write back the memory destination with implicit LOCK
2731 * prefix.
2732 */
2733 c->dst.val = c->src.val;
2734 c->lock_prefix = 1;
2735 break;
2736 case 0x88 ... 0x8b: /* mov */
2737 goto mov;
2738 case 0x8c: { /* mov r/m, sreg */
2739 struct kvm_segment segreg;
2740
2741 if (c->modrm_reg <= VCPU_SREG_GS)
2742 kvm_get_segment(ctxt->vcpu, &segreg, c->modrm_reg);
2743 else {
2744 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
2745 goto done;
2746 }
2747 c->dst.val = segreg.selector;
2748 break;
2749 }
2750 case 0x8d: /* lea r16/r32, m */
2751 c->dst.val = c->modrm_ea;
2752 break;
2753 case 0x8e: { /* mov seg, r/m16 */
2754 uint16_t sel;
2755
2756 sel = c->src.val;
2757
2758 if (c->modrm_reg == VCPU_SREG_CS ||
2759 c->modrm_reg > VCPU_SREG_GS) {
2760 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
2761 goto done;
2762 }
2763
2764 if (c->modrm_reg == VCPU_SREG_SS)
2765 toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_MOV_SS);
2766
2767 rc = load_segment_descriptor(ctxt, ops, sel, c->modrm_reg);
2768
2769 c->dst.type = OP_NONE; /* Disable writeback. */
2770 break;
2771 }
2772 case 0x8f: /* pop (sole member of Grp1a) */
2773 rc = emulate_grp1a(ctxt, ops);
2774 if (rc != X86EMUL_CONTINUE)
2775 goto done;
2776 break;
2777 case 0x90: /* nop / xchg r8,rax */
2778 if (!(c->rex_prefix & 1)) { /* nop */
2779 c->dst.type = OP_NONE;
2780 break;
2781 }
2782 case 0x91 ... 0x97: /* xchg reg,rax */
2783 c->src.type = c->dst.type = OP_REG;
2784 c->src.bytes = c->dst.bytes = c->op_bytes;
2785 c->src.ptr = (unsigned long *) &c->regs[VCPU_REGS_RAX];
2786 c->src.val = *(c->src.ptr);
2787 goto xchg;
2788 case 0x9c: /* pushf */
2789 c->src.val = (unsigned long) ctxt->eflags;
2790 emulate_push(ctxt);
2791 break;
2792 case 0x9d: /* popf */
2793 c->dst.type = OP_REG;
2794 c->dst.ptr = (unsigned long *) &ctxt->eflags;
2795 c->dst.bytes = c->op_bytes;
2796 rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes);
2797 if (rc != X86EMUL_CONTINUE)
2798 goto done;
2799 break;
2800 case 0xa0 ... 0xa1: /* mov */
2801 c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
2802 c->dst.val = c->src.val;
2803 break;
2804 case 0xa2 ... 0xa3: /* mov */
2805 c->dst.val = (unsigned long)c->regs[VCPU_REGS_RAX];
2806 break;
2807 case 0xa4 ... 0xa5: /* movs */
2808 goto mov;
2809 case 0xa6 ... 0xa7: /* cmps */
2810 c->dst.type = OP_NONE; /* Disable writeback. */
2811 DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr);
2812 goto cmp;
2813 case 0xaa ... 0xab: /* stos */
2814 c->dst.val = c->regs[VCPU_REGS_RAX];
2815 break;
2816 case 0xac ... 0xad: /* lods */
2817 goto mov;
2818 case 0xae ... 0xaf: /* scas */
2819 DPRINTF("Urk! I don't handle SCAS.\n");
2820 goto cannot_emulate;
2821 case 0xb0 ... 0xbf: /* mov r, imm */
2822 goto mov;
2823 case 0xc0 ... 0xc1:
2824 emulate_grp2(ctxt);
2825 break;
2826 case 0xc3: /* ret */
2827 c->dst.type = OP_REG;
2828 c->dst.ptr = &c->eip;
2829 c->dst.bytes = c->op_bytes;
2830 goto pop_instruction;
2831 case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */
2832 mov:
2833 c->dst.val = c->src.val;
2834 break;
2835 case 0xcb: /* ret far */
2836 rc = emulate_ret_far(ctxt, ops);
2837 if (rc != X86EMUL_CONTINUE)
2838 goto done;
2839 break;
2840 case 0xd0 ... 0xd1: /* Grp2 */
2841 c->src.val = 1;
2842 emulate_grp2(ctxt);
2843 break;
2844 case 0xd2 ... 0xd3: /* Grp2 */
2845 c->src.val = c->regs[VCPU_REGS_RCX];
2846 emulate_grp2(ctxt);
2847 break;
2848 case 0xe4: /* inb */
2849 case 0xe5: /* in */
2850 goto do_io_in;
2851 case 0xe6: /* outb */
2852 case 0xe7: /* out */
2853 goto do_io_out;
2854 case 0xe8: /* call (near) */ {
2855 long int rel = c->src.val;
2856 c->src.val = (unsigned long) c->eip;
2857 jmp_rel(c, rel);
2858 emulate_push(ctxt);
2859 break;
2860 }
2861 case 0xe9: /* jmp rel */
2862 goto jmp;
2863 case 0xea: /* jmp far */
2864 jump_far:
2865 if (load_segment_descriptor(ctxt, ops, c->src2.val,
2866 VCPU_SREG_CS))
2867 goto done;
2868
2869 c->eip = c->src.val;
2870 break;
2871 case 0xeb:
2872 jmp: /* jmp rel short */
2873 jmp_rel(c, c->src.val);
2874 c->dst.type = OP_NONE; /* Disable writeback. */
2875 break;
2876 case 0xec: /* in al,dx */
2877 case 0xed: /* in (e/r)ax,dx */
2878 c->src.val = c->regs[VCPU_REGS_RDX];
2879 do_io_in:
2880 c->dst.bytes = min(c->dst.bytes, 4u);
2881 if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {
2882 kvm_inject_gp(ctxt->vcpu, 0);
2883 goto done;
2884 }
2885 if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val,
2886 &c->dst.val))
2887 goto done; /* IO is needed */
2888 break;
2889 case 0xee: /* out al,dx */
2890 case 0xef: /* out (e/r)ax,dx */
2891 c->src.val = c->regs[VCPU_REGS_RDX];
2892 do_io_out:
2893 c->dst.bytes = min(c->dst.bytes, 4u);
2894 if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {
2895 kvm_inject_gp(ctxt->vcpu, 0);
2896 goto done;
2897 }
2898 ops->pio_out_emulated(c->dst.bytes, c->src.val, &c->dst.val, 1,
2899 ctxt->vcpu);
2900 c->dst.type = OP_NONE; /* Disable writeback. */
2901 break;
2902 case 0xf4: /* hlt */
2903 ctxt->vcpu->arch.halt_request = 1;
2904 break;
2905 case 0xf5: /* cmc */
2906 /* complement carry flag from eflags reg */
2907 ctxt->eflags ^= EFLG_CF;
2908 c->dst.type = OP_NONE; /* Disable writeback. */
2909 break;
2910 case 0xf6 ... 0xf7: /* Grp3 */
2911 if (!emulate_grp3(ctxt, ops))
2912 goto cannot_emulate;
2913 break;
2914 case 0xf8: /* clc */
2915 ctxt->eflags &= ~EFLG_CF;
2916 c->dst.type = OP_NONE; /* Disable writeback. */
2917 break;
2918 case 0xfa: /* cli */
2919 if (emulator_bad_iopl(ctxt, ops))
2920 kvm_inject_gp(ctxt->vcpu, 0);
2921 else {
2922 ctxt->eflags &= ~X86_EFLAGS_IF;
2923 c->dst.type = OP_NONE; /* Disable writeback. */
2924 }
2925 break;
2926 case 0xfb: /* sti */
2927 if (emulator_bad_iopl(ctxt, ops))
2928 kvm_inject_gp(ctxt->vcpu, 0);
2929 else {
2930 toggle_interruptibility(ctxt, KVM_X86_SHADOW_INT_STI);
2931 ctxt->eflags |= X86_EFLAGS_IF;
2932 c->dst.type = OP_NONE; /* Disable writeback. */
2933 }
2934 break;
2935 case 0xfc: /* cld */
2936 ctxt->eflags &= ~EFLG_DF;
2937 c->dst.type = OP_NONE; /* Disable writeback. */
2938 break;
2939 case 0xfd: /* std */
2940 ctxt->eflags |= EFLG_DF;
2941 c->dst.type = OP_NONE; /* Disable writeback. */
2942 break;
2943 case 0xfe: /* Grp4 */
2944 grp45:
2945 rc = emulate_grp45(ctxt, ops);
2946 if (rc != X86EMUL_CONTINUE)
2947 goto done;
2948 break;
2949 case 0xff: /* Grp5 */
2950 if (c->modrm_reg == 5)
2951 goto jump_far;
2952 goto grp45;
2953 }
2954
2955 writeback:
2956 rc = writeback(ctxt, ops);
2957 if (rc != X86EMUL_CONTINUE)
2958 goto done;
2959
2960 /*
2961 * restore dst type in case the decoding will be reused
2962 * (happens for string instruction )
2963 */
2964 c->dst.type = saved_dst_type;
2965
2966 if ((c->d & SrcMask) == SrcSI)
2967 string_addr_inc(ctxt, seg_override_base(ctxt, c), VCPU_REGS_RSI,
2968 &c->src);
2969
2970 if ((c->d & DstMask) == DstDI)
2971 string_addr_inc(ctxt, es_base(ctxt), VCPU_REGS_RDI, &c->dst);
2972
2973 if (c->rep_prefix && (c->d & String)) {
2974 struct read_cache *rc = &ctxt->decode.io_read;
2975 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
2976 /*
2977 * Re-enter guest when pio read ahead buffer is empty or,
2978 * if it is not used, after each 1024 iteration.
2979 */
2980 if ((rc->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) ||
2981 (rc->end != 0 && rc->end == rc->pos))
2982 ctxt->restart = false;
2983 }
2984
2985 /* Commit shadow register state. */
2986 memcpy(ctxt->vcpu->arch.regs, c->regs, sizeof c->regs);
2987 kvm_rip_write(ctxt->vcpu, c->eip);
2988 ops->set_rflags(ctxt->vcpu, ctxt->eflags);
2989
2990 done:
2991 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
2992
2993 twobyte_insn:
2994 switch (c->b) {
2995 case 0x01: /* lgdt, lidt, lmsw */
2996 switch (c->modrm_reg) {
2997 u16 size;
2998 unsigned long address;
2999
3000 case 0: /* vmcall */
3001 if (c->modrm_mod != 3 || c->modrm_rm != 1)
3002 goto cannot_emulate;
3003
3004 rc = kvm_fix_hypercall(ctxt->vcpu);
3005 if (rc != X86EMUL_CONTINUE)
3006 goto done;
3007
3008 /* Let the processor re-execute the fixed hypercall */
3009 c->eip = ctxt->eip;
3010 /* Disable writeback. */
3011 c->dst.type = OP_NONE;
3012 break;
3013 case 2: /* lgdt */
3014 rc = read_descriptor(ctxt, ops, c->src.ptr,
3015 &size, &address, c->op_bytes);
3016 if (rc != X86EMUL_CONTINUE)
3017 goto done;
3018 realmode_lgdt(ctxt->vcpu, size, address);
3019 /* Disable writeback. */
3020 c->dst.type = OP_NONE;
3021 break;
3022 case 3: /* lidt/vmmcall */
3023 if (c->modrm_mod == 3) {
3024 switch (c->modrm_rm) {
3025 case 1:
3026 rc = kvm_fix_hypercall(ctxt->vcpu);
3027 if (rc != X86EMUL_CONTINUE)
3028 goto done;
3029 break;
3030 default:
3031 goto cannot_emulate;
3032 }
3033 } else {
3034 rc = read_descriptor(ctxt, ops, c->src.ptr,
3035 &size, &address,
3036 c->op_bytes);
3037 if (rc != X86EMUL_CONTINUE)
3038 goto done;
3039 realmode_lidt(ctxt->vcpu, size, address);
3040 }
3041 /* Disable writeback. */
3042 c->dst.type = OP_NONE;
3043 break;
3044 case 4: /* smsw */
3045 c->dst.bytes = 2;
3046 c->dst.val = ops->get_cr(0, ctxt->vcpu);
3047 break;
3048 case 6: /* lmsw */
3049 ops->set_cr(0, (ops->get_cr(0, ctxt->vcpu) & ~0x0ful) |
3050 (c->src.val & 0x0f), ctxt->vcpu);
3051 c->dst.type = OP_NONE;
3052 break;
3053 case 5: /* not defined */
3054 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
3055 goto done;
3056 case 7: /* invlpg*/
3057 emulate_invlpg(ctxt->vcpu, c->modrm_ea);
3058 /* Disable writeback. */
3059 c->dst.type = OP_NONE;
3060 break;
3061 default:
3062 goto cannot_emulate;
3063 }
3064 break;
3065 case 0x05: /* syscall */
3066 rc = emulate_syscall(ctxt);
3067 if (rc != X86EMUL_CONTINUE)
3068 goto done;
3069 else
3070 goto writeback;
3071 break;
3072 case 0x06:
3073 emulate_clts(ctxt->vcpu);
3074 c->dst.type = OP_NONE;
3075 break;
3076 case 0x08: /* invd */
3077 case 0x09: /* wbinvd */
3078 case 0x0d: /* GrpP (prefetch) */
3079 case 0x18: /* Grp16 (prefetch/nop) */
3080 c->dst.type = OP_NONE;
3081 break;
3082 case 0x20: /* mov cr, reg */
3083 switch (c->modrm_reg) {
3084 case 1:
3085 case 5 ... 7:
3086 case 9 ... 15:
3087 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
3088 goto done;
3089 }
3090 c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu);
3091 c->dst.type = OP_NONE; /* no writeback */
3092 break;
3093 case 0x21: /* mov from dr to reg */
3094 if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
3095 (c->modrm_reg == 4 || c->modrm_reg == 5)) {
3096 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
3097 goto done;
3098 }
3099 emulator_get_dr(ctxt, c->modrm_reg, &c->regs[c->modrm_rm]);
3100 c->dst.type = OP_NONE; /* no writeback */
3101 break;
3102 case 0x22: /* mov reg, cr */
3103 ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu);
3104 c->dst.type = OP_NONE;
3105 break;
3106 case 0x23: /* mov from reg to dr */
3107 if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
3108 (c->modrm_reg == 4 || c->modrm_reg == 5)) {
3109 kvm_queue_exception(ctxt->vcpu, UD_VECTOR);
3110 goto done;
3111 }
3112 emulator_set_dr(ctxt, c->modrm_reg, c->regs[c->modrm_rm]);
3113 c->dst.type = OP_NONE; /* no writeback */
3114 break;
3115 case 0x30:
3116 /* wrmsr */
3117 msr_data = (u32)c->regs[VCPU_REGS_RAX]
3118 | ((u64)c->regs[VCPU_REGS_RDX] << 32);
3119 if (kvm_set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data)) {
3120 kvm_inject_gp(ctxt->vcpu, 0);
3121 goto done;
3122 }
3123 rc = X86EMUL_CONTINUE;
3124 c->dst.type = OP_NONE;
3125 break;
3126 case 0x32:
3127 /* rdmsr */
3128 if (kvm_get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data)) {
3129 kvm_inject_gp(ctxt->vcpu, 0);
3130 goto done;
3131 } else {
3132 c->regs[VCPU_REGS_RAX] = (u32)msr_data;
3133 c->regs[VCPU_REGS_RDX] = msr_data >> 32;
3134 }
3135 rc = X86EMUL_CONTINUE;
3136 c->dst.type = OP_NONE;
3137 break;
3138 case 0x34: /* sysenter */
3139 rc = emulate_sysenter(ctxt);
3140 if (rc != X86EMUL_CONTINUE)
3141 goto done;
3142 else
3143 goto writeback;
3144 break;
3145 case 0x35: /* sysexit */
3146 rc = emulate_sysexit(ctxt);
3147 if (rc != X86EMUL_CONTINUE)
3148 goto done;
3149 else
3150 goto writeback;
3151 break;
3152 case 0x40 ... 0x4f: /* cmov */
3153 c->dst.val = c->dst.orig_val = c->src.val;
3154 if (!test_cc(c->b, ctxt->eflags))
3155 c->dst.type = OP_NONE; /* no writeback */
3156 break;
3157 case 0x80 ... 0x8f: /* jnz rel, etc*/
3158 if (test_cc(c->b, ctxt->eflags))
3159 jmp_rel(c, c->src.val);
3160 c->dst.type = OP_NONE;
3161 break;
3162 case 0xa0: /* push fs */
3163 emulate_push_sreg(ctxt, VCPU_SREG_FS);
3164 break;
3165 case 0xa1: /* pop fs */
3166 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_FS);
3167 if (rc != X86EMUL_CONTINUE)
3168 goto done;
3169 break;
3170 case 0xa3:
3171 bt: /* bt */
3172 c->dst.type = OP_NONE;
3173 /* only subword offset */
3174 c->src.val &= (c->dst.bytes << 3) - 1;
3175 emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags);
3176 break;
3177 case 0xa4: /* shld imm8, r, r/m */
3178 case 0xa5: /* shld cl, r, r/m */
3179 emulate_2op_cl("shld", c->src2, c->src, c->dst, ctxt->eflags);
3180 break;
3181 case 0xa8: /* push gs */
3182 emulate_push_sreg(ctxt, VCPU_SREG_GS);
3183 break;
3184 case 0xa9: /* pop gs */
3185 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_GS);
3186 if (rc != X86EMUL_CONTINUE)
3187 goto done;
3188 break;
3189 case 0xab:
3190 bts: /* bts */
3191 /* only subword offset */
3192 c->src.val &= (c->dst.bytes << 3) - 1;
3193 emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags);
3194 break;
3195 case 0xac: /* shrd imm8, r, r/m */
3196 case 0xad: /* shrd cl, r, r/m */
3197 emulate_2op_cl("shrd", c->src2, c->src, c->dst, ctxt->eflags);
3198 break;
3199 case 0xae: /* clflush */
3200 break;
3201 case 0xb0 ... 0xb1: /* cmpxchg */
3202 /*
3203 * Save real source value, then compare EAX against
3204 * destination.
3205 */
3206 c->src.orig_val = c->src.val;
3207 c->src.val = c->regs[VCPU_REGS_RAX];
3208 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
3209 if (ctxt->eflags & EFLG_ZF) {
3210 /* Success: write back to memory. */
3211 c->dst.val = c->src.orig_val;
3212 } else {
3213 /* Failure: write the value we saw to EAX. */
3214 c->dst.type = OP_REG;
3215 c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX];
3216 }
3217 break;
3218 case 0xb3:
3219 btr: /* btr */
3220 /* only subword offset */
3221 c->src.val &= (c->dst.bytes << 3) - 1;
3222 emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags);
3223 break;
3224 case 0xb6 ... 0xb7: /* movzx */
3225 c->dst.bytes = c->op_bytes;
3226 c->dst.val = (c->d & ByteOp) ? (u8) c->src.val
3227 : (u16) c->src.val;
3228 break;
3229 case 0xba: /* Grp8 */
3230 switch (c->modrm_reg & 3) {
3231 case 0:
3232 goto bt;
3233 case 1:
3234 goto bts;
3235 case 2:
3236 goto btr;
3237 case 3:
3238 goto btc;
3239 }
3240 break;
3241 case 0xbb:
3242 btc: /* btc */
3243 /* only subword offset */
3244 c->src.val &= (c->dst.bytes << 3) - 1;
3245 emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
3246 break;
3247 case 0xbe ... 0xbf: /* movsx */
3248 c->dst.bytes = c->op_bytes;
3249 c->dst.val = (c->d & ByteOp) ? (s8) c->src.val :
3250 (s16) c->src.val;
3251 break;
3252 case 0xc3: /* movnti */
3253 c->dst.bytes = c->op_bytes;
3254 c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val :
3255 (u64) c->src.val;
3256 break;
3257 case 0xc7: /* Grp9 (cmpxchg8b) */
3258 rc = emulate_grp9(ctxt, ops);
3259 if (rc != X86EMUL_CONTINUE)
3260 goto done;
3261 break;
3262 }
3263 goto writeback;
3264
3265 cannot_emulate:
3266 DPRINTF("Cannot emulate %02x\n", c->b);
3267 return -1;
3268 }
Linux kernel - Deliverables
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