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 * Copyright 2010 Red Hat, Inc. and/or its affilates. 13 * 14 * Avi Kivity <avi@qumranet.com> 15 * Yaniv Kamay <yaniv@qumranet.com> 16 * 17 * This work is licensed under the terms of the GNU GPL, version 2. See 18 * the COPYING file in the top-level directory. 19 * 20 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 21 */ 22 23 #ifndef __KERNEL__ 24 #include <stdio.h> 25 #include <stdint.h> 26 #include <public/xen.h> 27 #define DPRINTF(_f, _a ...) printf(_f , ## _a) 28 #else 29 #include <linux/kvm_host.h> 30 #include "kvm_cache_regs.h" 31 #define DPRINTF(x...) do {} while (0) 32 #endif 33 #include <linux/module.h> 34 #include <asm/kvm_emulate.h> 35 36 #include "x86.h" 37 #include "tss.h" 38 39 /* 40 * Opcode effective-address decode tables. 41 * Note that we only emulate instructions that have at least one memory 42 * operand (excluding implicit stack references). We assume that stack 43 * references and instruction fetches will never occur in special memory 44 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need 45 * not be handled. 46 */ 47 48 /* Operand sizes: 8-bit operands or specified/overridden size. */ 49 #define ByteOp (1<<0) /* 8-bit operands. */ 50 /* Destination operand type. */ 51 #define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */ 52 #define DstReg (2<<1) /* Register operand. */ 53 #define DstMem (3<<1) /* Memory operand. */ 54 #define DstAcc (4<<1) /* Destination Accumulator */ 55 #define DstDI (5<<1) /* Destination is in ES:(E)DI */ 56 #define DstMem64 (6<<1) /* 64bit memory operand */ 57 #define DstMask (7<<1) 58 /* Source operand type. */ 59 #define SrcNone (0<<4) /* No source operand. */ 60 #define SrcImplicit (0<<4) /* Source operand is implicit in the opcode. */ 61 #define SrcReg (1<<4) /* Register operand. */ 62 #define SrcMem (2<<4) /* Memory operand. */ 63 #define SrcMem16 (3<<4) /* Memory operand (16-bit). */ 64 #define SrcMem32 (4<<4) /* Memory operand (32-bit). */ 65 #define SrcImm (5<<4) /* Immediate operand. */ 66 #define SrcImmByte (6<<4) /* 8-bit sign-extended immediate operand. */ 67 #define SrcOne (7<<4) /* Implied '1' */ 68 #define SrcImmUByte (8<<4) /* 8-bit unsigned immediate operand. */ 69 #define SrcImmU (9<<4) /* Immediate operand, unsigned */ 70 #define SrcSI (0xa<<4) /* Source is in the DS:RSI */ 71 #define SrcImmFAddr (0xb<<4) /* Source is immediate far address */ 72 #define SrcMemFAddr (0xc<<4) /* Source is far address in memory */ 73 #define SrcAcc (0xd<<4) /* Source Accumulator */ 74 #define SrcMask (0xf<<4) 75 /* Generic ModRM decode. */ 76 #define ModRM (1<<8) 77 /* Destination is only written; never read. */ 78 #define Mov (1<<9) 79 #define BitOp (1<<10) 80 #define MemAbs (1<<11) /* Memory operand is absolute displacement */ 81 #define String (1<<12) /* String instruction (rep capable) */ 82 #define Stack (1<<13) /* Stack instruction (push/pop) */ 83 #define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */ 84 #define GroupDual (1<<15) /* Alternate decoding of mod == 3 */ 85 #define GroupMask 0xff /* Group number stored in bits 0:7 */ 86 /* Misc flags */ 87 #define Lock (1<<26) /* lock prefix is allowed for the instruction */ 88 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ 89 #define No64 (1<<28) 90 /* Source 2 operand type */ 91 #define Src2None (0<<29) 92 #define Src2CL (1<<29) 93 #define Src2ImmByte (2<<29) 94 #define Src2One (3<<29) 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 ByteOp | 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 ByteOp | DstAcc | SrcImmByte, DstAcc | SrcImm, 0, 0, 132 /* 0x30 - 0x37 */ 133 ByteOp | DstMem | SrcReg | ModRM | Lock, DstMem | SrcReg | ModRM | Lock, 134 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM, 135 ByteOp | DstAcc | SrcImmByte, DstAcc | SrcImm, 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 | SrcNone | ModRM | Mov, ModRM | DstReg, 174 ImplicitOps | SrcMem16 | ModRM, Group | Group1A, 175 /* 0x90 - 0x97 */ 176 DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, DstReg, 177 /* 0x98 - 0x9F */ 178 0, 0, SrcImmFAddr | No64, 0, 179 ImplicitOps | Stack, ImplicitOps | Stack, 0, 0, 180 /* 0xA0 - 0xA7 */ 181 ByteOp | DstAcc | SrcMem | Mov | MemAbs, DstAcc | SrcMem | Mov | MemAbs, 182 ByteOp | DstMem | SrcAcc | Mov | MemAbs, DstMem | SrcAcc | Mov | MemAbs, 183 ByteOp | SrcSI | DstDI | Mov | String, SrcSI | DstDI | Mov | String, 184 ByteOp | SrcSI | DstDI | String, SrcSI | DstDI | String, 185 /* 0xA8 - 0xAF */ 186 DstAcc | SrcImmByte | ByteOp, DstAcc | SrcImm, 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 SrcImmFAddr | 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, ByteOp | SrcImm | DstMem | ModRM, 341 ByteOp | DstMem | SrcNone | ModRM, ByteOp | DstMem | SrcNone | ModRM, 342 0, 0, 0, 0, 343 [Group3*8] = 344 DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM, 345 DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM, 346 0, 0, 0, 0, 347 [Group4*8] = 348 ByteOp | DstMem | SrcNone | ModRM | Lock, ByteOp | DstMem | SrcNone | ModRM | Lock, 349 0, 0, 0, 0, 0, 0, 350 [Group5*8] = 351 DstMem | SrcNone | ModRM | Lock, DstMem | SrcNone | ModRM | Lock, 352 SrcMem | ModRM | Stack, 0, 353 SrcMem | ModRM | Stack, SrcMemFAddr | ModRM | 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 #define insn_fetch_arr(_arr, _size, _eip) \ 580 ({ rc = do_insn_fetch(ctxt, ops, (_eip), _arr, (_size)); \ 581 if (rc != X86EMUL_CONTINUE) \ 582 goto done; \ 583 (_eip) += (_size); \ 584 }) 585 586 static inline unsigned long ad_mask(struct decode_cache *c) 587 { 588 return (1UL << (c->ad_bytes << 3)) - 1; 589 } 590 591 /* Access/update address held in a register, based on addressing mode. */ 592 static inline unsigned long 593 address_mask(struct decode_cache *c, unsigned long reg) 594 { 595 if (c->ad_bytes == sizeof(unsigned long)) 596 return reg; 597 else 598 return reg & ad_mask(c); 599 } 600 601 static inline unsigned long 602 register_address(struct decode_cache *c, unsigned long base, unsigned long reg) 603 { 604 return base + address_mask(c, reg); 605 } 606 607 static inline void 608 register_address_increment(struct decode_cache *c, unsigned long *reg, int inc) 609 { 610 if (c->ad_bytes == sizeof(unsigned long)) 611 *reg += inc; 612 else 613 *reg = (*reg & ~ad_mask(c)) | ((*reg + inc) & ad_mask(c)); 614 } 615 616 static inline void jmp_rel(struct decode_cache *c, int rel) 617 { 618 register_address_increment(c, &c->eip, rel); 619 } 620 621 static void set_seg_override(struct decode_cache *c, int seg) 622 { 623 c->has_seg_override = true; 624 c->seg_override = seg; 625 } 626 627 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, 628 struct x86_emulate_ops *ops, int seg) 629 { 630 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) 631 return 0; 632 633 return ops->get_cached_segment_base(seg, ctxt->vcpu); 634 } 635 636 static unsigned long seg_override_base(struct x86_emulate_ctxt *ctxt, 637 struct x86_emulate_ops *ops, 638 struct decode_cache *c) 639 { 640 if (!c->has_seg_override) 641 return 0; 642 643 return seg_base(ctxt, ops, c->seg_override); 644 } 645 646 static unsigned long es_base(struct x86_emulate_ctxt *ctxt, 647 struct x86_emulate_ops *ops) 648 { 649 return seg_base(ctxt, ops, VCPU_SREG_ES); 650 } 651 652 static unsigned long ss_base(struct x86_emulate_ctxt *ctxt, 653 struct x86_emulate_ops *ops) 654 { 655 return seg_base(ctxt, ops, VCPU_SREG_SS); 656 } 657 658 static void emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, 659 u32 error, bool valid) 660 { 661 ctxt->exception = vec; 662 ctxt->error_code = error; 663 ctxt->error_code_valid = valid; 664 ctxt->restart = false; 665 } 666 667 static void emulate_gp(struct x86_emulate_ctxt *ctxt, int err) 668 { 669 emulate_exception(ctxt, GP_VECTOR, err, true); 670 } 671 672 static void emulate_pf(struct x86_emulate_ctxt *ctxt, unsigned long addr, 673 int err) 674 { 675 ctxt->cr2 = addr; 676 emulate_exception(ctxt, PF_VECTOR, err, true); 677 } 678 679 static void emulate_ud(struct x86_emulate_ctxt *ctxt) 680 { 681 emulate_exception(ctxt, UD_VECTOR, 0, false); 682 } 683 684 static void emulate_ts(struct x86_emulate_ctxt *ctxt, int err) 685 { 686 emulate_exception(ctxt, TS_VECTOR, err, true); 687 } 688 689 static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt, 690 struct x86_emulate_ops *ops, 691 unsigned long eip, u8 *dest) 692 { 693 struct fetch_cache *fc = &ctxt->decode.fetch; 694 int rc; 695 int size, cur_size; 696 697 if (eip == fc->end) { 698 cur_size = fc->end - fc->start; 699 size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(eip)); 700 rc = ops->fetch(ctxt->cs_base + eip, fc->data + cur_size, 701 size, ctxt->vcpu, NULL); 702 if (rc != X86EMUL_CONTINUE) 703 return rc; 704 fc->end += size; 705 } 706 *dest = fc->data[eip - fc->start]; 707 return X86EMUL_CONTINUE; 708 } 709 710 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, 711 struct x86_emulate_ops *ops, 712 unsigned long eip, void *dest, unsigned size) 713 { 714 int rc; 715 716 /* x86 instructions are limited to 15 bytes. */ 717 if (eip + size - ctxt->eip > 15) 718 return X86EMUL_UNHANDLEABLE; 719 while (size--) { 720 rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++); 721 if (rc != X86EMUL_CONTINUE) 722 return rc; 723 } 724 return X86EMUL_CONTINUE; 725 } 726 727 /* 728 * Given the 'reg' portion of a ModRM byte, and a register block, return a 729 * pointer into the block that addresses the relevant register. 730 * @highbyte_regs specifies whether to decode AH,CH,DH,BH. 731 */ 732 static void *decode_register(u8 modrm_reg, unsigned long *regs, 733 int highbyte_regs) 734 { 735 void *p; 736 737 p = ®s[modrm_reg]; 738 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) 739 p = (unsigned char *)®s[modrm_reg & 3] + 1; 740 return p; 741 } 742 743 static int read_descriptor(struct x86_emulate_ctxt *ctxt, 744 struct x86_emulate_ops *ops, 745 void *ptr, 746 u16 *size, unsigned long *address, int op_bytes) 747 { 748 int rc; 749 750 if (op_bytes == 2) 751 op_bytes = 3; 752 *address = 0; 753 rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2, 754 ctxt->vcpu, NULL); 755 if (rc != X86EMUL_CONTINUE) 756 return rc; 757 rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes, 758 ctxt->vcpu, NULL); 759 return rc; 760 } 761 762 static int test_cc(unsigned int condition, unsigned int flags) 763 { 764 int rc = 0; 765 766 switch ((condition & 15) >> 1) { 767 case 0: /* o */ 768 rc |= (flags & EFLG_OF); 769 break; 770 case 1: /* b/c/nae */ 771 rc |= (flags & EFLG_CF); 772 break; 773 case 2: /* z/e */ 774 rc |= (flags & EFLG_ZF); 775 break; 776 case 3: /* be/na */ 777 rc |= (flags & (EFLG_CF|EFLG_ZF)); 778 break; 779 case 4: /* s */ 780 rc |= (flags & EFLG_SF); 781 break; 782 case 5: /* p/pe */ 783 rc |= (flags & EFLG_PF); 784 break; 785 case 7: /* le/ng */ 786 rc |= (flags & EFLG_ZF); 787 /* fall through */ 788 case 6: /* l/nge */ 789 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF)); 790 break; 791 } 792 793 /* Odd condition identifiers (lsb == 1) have inverted sense. */ 794 return (!!rc ^ (condition & 1)); 795 } 796 797 static void decode_register_operand(struct operand *op, 798 struct decode_cache *c, 799 int inhibit_bytereg) 800 { 801 unsigned reg = c->modrm_reg; 802 int highbyte_regs = c->rex_prefix == 0; 803 804 if (!(c->d & ModRM)) 805 reg = (c->b & 7) | ((c->rex_prefix & 1) << 3); 806 op->type = OP_REG; 807 if ((c->d & ByteOp) && !inhibit_bytereg) { 808 op->ptr = decode_register(reg, c->regs, highbyte_regs); 809 op->val = *(u8 *)op->ptr; 810 op->bytes = 1; 811 } else { 812 op->ptr = decode_register(reg, c->regs, 0); 813 op->bytes = c->op_bytes; 814 switch (op->bytes) { 815 case 2: 816 op->val = *(u16 *)op->ptr; 817 break; 818 case 4: 819 op->val = *(u32 *)op->ptr; 820 break; 821 case 8: 822 op->val = *(u64 *) op->ptr; 823 break; 824 } 825 } 826 op->orig_val = op->val; 827 } 828 829 static int decode_modrm(struct x86_emulate_ctxt *ctxt, 830 struct x86_emulate_ops *ops) 831 { 832 struct decode_cache *c = &ctxt->decode; 833 u8 sib; 834 int index_reg = 0, base_reg = 0, scale; 835 int rc = X86EMUL_CONTINUE; 836 837 if (c->rex_prefix) { 838 c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */ 839 index_reg = (c->rex_prefix & 2) << 2; /* REX.X */ 840 c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */ 841 } 842 843 c->modrm = insn_fetch(u8, 1, c->eip); 844 c->modrm_mod |= (c->modrm & 0xc0) >> 6; 845 c->modrm_reg |= (c->modrm & 0x38) >> 3; 846 c->modrm_rm |= (c->modrm & 0x07); 847 c->modrm_ea = 0; 848 c->use_modrm_ea = 1; 849 850 if (c->modrm_mod == 3) { 851 c->modrm_ptr = decode_register(c->modrm_rm, 852 c->regs, c->d & ByteOp); 853 c->modrm_val = *(unsigned long *)c->modrm_ptr; 854 return rc; 855 } 856 857 if (c->ad_bytes == 2) { 858 unsigned bx = c->regs[VCPU_REGS_RBX]; 859 unsigned bp = c->regs[VCPU_REGS_RBP]; 860 unsigned si = c->regs[VCPU_REGS_RSI]; 861 unsigned di = c->regs[VCPU_REGS_RDI]; 862 863 /* 16-bit ModR/M decode. */ 864 switch (c->modrm_mod) { 865 case 0: 866 if (c->modrm_rm == 6) 867 c->modrm_ea += insn_fetch(u16, 2, c->eip); 868 break; 869 case 1: 870 c->modrm_ea += insn_fetch(s8, 1, c->eip); 871 break; 872 case 2: 873 c->modrm_ea += insn_fetch(u16, 2, c->eip); 874 break; 875 } 876 switch (c->modrm_rm) { 877 case 0: 878 c->modrm_ea += bx + si; 879 break; 880 case 1: 881 c->modrm_ea += bx + di; 882 break; 883 case 2: 884 c->modrm_ea += bp + si; 885 break; 886 case 3: 887 c->modrm_ea += bp + di; 888 break; 889 case 4: 890 c->modrm_ea += si; 891 break; 892 case 5: 893 c->modrm_ea += di; 894 break; 895 case 6: 896 if (c->modrm_mod != 0) 897 c->modrm_ea += bp; 898 break; 899 case 7: 900 c->modrm_ea += bx; 901 break; 902 } 903 if (c->modrm_rm == 2 || c->modrm_rm == 3 || 904 (c->modrm_rm == 6 && c->modrm_mod != 0)) 905 if (!c->has_seg_override) 906 set_seg_override(c, VCPU_SREG_SS); 907 c->modrm_ea = (u16)c->modrm_ea; 908 } else { 909 /* 32/64-bit ModR/M decode. */ 910 if ((c->modrm_rm & 7) == 4) { 911 sib = insn_fetch(u8, 1, c->eip); 912 index_reg |= (sib >> 3) & 7; 913 base_reg |= sib & 7; 914 scale = sib >> 6; 915 916 if ((base_reg & 7) == 5 && c->modrm_mod == 0) 917 c->modrm_ea += insn_fetch(s32, 4, c->eip); 918 else 919 c->modrm_ea += c->regs[base_reg]; 920 if (index_reg != 4) 921 c->modrm_ea += c->regs[index_reg] << scale; 922 } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) { 923 if (ctxt->mode == X86EMUL_MODE_PROT64) 924 c->rip_relative = 1; 925 } else 926 c->modrm_ea += c->regs[c->modrm_rm]; 927 switch (c->modrm_mod) { 928 case 0: 929 if (c->modrm_rm == 5) 930 c->modrm_ea += insn_fetch(s32, 4, c->eip); 931 break; 932 case 1: 933 c->modrm_ea += insn_fetch(s8, 1, c->eip); 934 break; 935 case 2: 936 c->modrm_ea += insn_fetch(s32, 4, c->eip); 937 break; 938 } 939 } 940 done: 941 return rc; 942 } 943 944 static int decode_abs(struct x86_emulate_ctxt *ctxt, 945 struct x86_emulate_ops *ops) 946 { 947 struct decode_cache *c = &ctxt->decode; 948 int rc = X86EMUL_CONTINUE; 949 950 switch (c->ad_bytes) { 951 case 2: 952 c->modrm_ea = insn_fetch(u16, 2, c->eip); 953 break; 954 case 4: 955 c->modrm_ea = insn_fetch(u32, 4, c->eip); 956 break; 957 case 8: 958 c->modrm_ea = insn_fetch(u64, 8, c->eip); 959 break; 960 } 961 done: 962 return rc; 963 } 964 965 int 966 x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 967 { 968 struct decode_cache *c = &ctxt->decode; 969 int rc = X86EMUL_CONTINUE; 970 int mode = ctxt->mode; 971 int def_op_bytes, def_ad_bytes, group; 972 973 974 /* we cannot decode insn before we complete previous rep insn */ 975 WARN_ON(ctxt->restart); 976 977 c->eip = ctxt->eip; 978 c->fetch.start = c->fetch.end = c->eip; 979 ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS); 980 981 switch (mode) { 982 case X86EMUL_MODE_REAL: 983 case X86EMUL_MODE_VM86: 984 case X86EMUL_MODE_PROT16: 985 def_op_bytes = def_ad_bytes = 2; 986 break; 987 case X86EMUL_MODE_PROT32: 988 def_op_bytes = def_ad_bytes = 4; 989 break; 990 #ifdef CONFIG_X86_64 991 case X86EMUL_MODE_PROT64: 992 def_op_bytes = 4; 993 def_ad_bytes = 8; 994 break; 995 #endif 996 default: 997 return -1; 998 } 999 1000 c->op_bytes = def_op_bytes; 1001 c->ad_bytes = def_ad_bytes; 1002 1003 /* Legacy prefixes. */ 1004 for (;;) { 1005 switch (c->b = insn_fetch(u8, 1, c->eip)) { 1006 case 0x66: /* operand-size override */ 1007 /* switch between 2/4 bytes */ 1008 c->op_bytes = def_op_bytes ^ 6; 1009 break; 1010 case 0x67: /* address-size override */ 1011 if (mode == X86EMUL_MODE_PROT64) 1012 /* switch between 4/8 bytes */ 1013 c->ad_bytes = def_ad_bytes ^ 12; 1014 else 1015 /* switch between 2/4 bytes */ 1016 c->ad_bytes = def_ad_bytes ^ 6; 1017 break; 1018 case 0x26: /* ES override */ 1019 case 0x2e: /* CS override */ 1020 case 0x36: /* SS override */ 1021 case 0x3e: /* DS override */ 1022 set_seg_override(c, (c->b >> 3) & 3); 1023 break; 1024 case 0x64: /* FS override */ 1025 case 0x65: /* GS override */ 1026 set_seg_override(c, c->b & 7); 1027 break; 1028 case 0x40 ... 0x4f: /* REX */ 1029 if (mode != X86EMUL_MODE_PROT64) 1030 goto done_prefixes; 1031 c->rex_prefix = c->b; 1032 continue; 1033 case 0xf0: /* LOCK */ 1034 c->lock_prefix = 1; 1035 break; 1036 case 0xf2: /* REPNE/REPNZ */ 1037 c->rep_prefix = REPNE_PREFIX; 1038 break; 1039 case 0xf3: /* REP/REPE/REPZ */ 1040 c->rep_prefix = REPE_PREFIX; 1041 break; 1042 default: 1043 goto done_prefixes; 1044 } 1045 1046 /* Any legacy prefix after a REX prefix nullifies its effect. */ 1047 1048 c->rex_prefix = 0; 1049 } 1050 1051 done_prefixes: 1052 1053 /* REX prefix. */ 1054 if (c->rex_prefix) 1055 if (c->rex_prefix & 8) 1056 c->op_bytes = 8; /* REX.W */ 1057 1058 /* Opcode byte(s). */ 1059 c->d = opcode_table[c->b]; 1060 if (c->d == 0) { 1061 /* Two-byte opcode? */ 1062 if (c->b == 0x0f) { 1063 c->twobyte = 1; 1064 c->b = insn_fetch(u8, 1, c->eip); 1065 c->d = twobyte_table[c->b]; 1066 } 1067 } 1068 1069 if (c->d & Group) { 1070 group = c->d & GroupMask; 1071 c->modrm = insn_fetch(u8, 1, c->eip); 1072 --c->eip; 1073 1074 group = (group << 3) + ((c->modrm >> 3) & 7); 1075 if ((c->d & GroupDual) && (c->modrm >> 6) == 3) 1076 c->d = group2_table[group]; 1077 else 1078 c->d = group_table[group]; 1079 } 1080 1081 /* Unrecognised? */ 1082 if (c->d == 0) { 1083 DPRINTF("Cannot emulate %02x\n", c->b); 1084 return -1; 1085 } 1086 1087 if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack)) 1088 c->op_bytes = 8; 1089 1090 /* ModRM and SIB bytes. */ 1091 if (c->d & ModRM) 1092 rc = decode_modrm(ctxt, ops); 1093 else if (c->d & MemAbs) 1094 rc = decode_abs(ctxt, ops); 1095 if (rc != X86EMUL_CONTINUE) 1096 goto done; 1097 1098 if (!c->has_seg_override) 1099 set_seg_override(c, VCPU_SREG_DS); 1100 1101 if (!(!c->twobyte && c->b == 0x8d)) 1102 c->modrm_ea += seg_override_base(ctxt, ops, c); 1103 1104 if (c->ad_bytes != 8) 1105 c->modrm_ea = (u32)c->modrm_ea; 1106 1107 if (c->rip_relative) 1108 c->modrm_ea += c->eip; 1109 1110 /* 1111 * Decode and fetch the source operand: register, memory 1112 * or immediate. 1113 */ 1114 switch (c->d & SrcMask) { 1115 case SrcNone: 1116 break; 1117 case SrcReg: 1118 decode_register_operand(&c->src, c, 0); 1119 break; 1120 case SrcMem16: 1121 c->src.bytes = 2; 1122 goto srcmem_common; 1123 case SrcMem32: 1124 c->src.bytes = 4; 1125 goto srcmem_common; 1126 case SrcMem: 1127 c->src.bytes = (c->d & ByteOp) ? 1 : 1128 c->op_bytes; 1129 /* Don't fetch the address for invlpg: it could be unmapped. */ 1130 if (c->twobyte && c->b == 0x01 && c->modrm_reg == 7) 1131 break; 1132 srcmem_common: 1133 /* 1134 * For instructions with a ModR/M byte, switch to register 1135 * access if Mod = 3. 1136 */ 1137 if ((c->d & ModRM) && c->modrm_mod == 3) { 1138 c->src.type = OP_REG; 1139 c->src.val = c->modrm_val; 1140 c->src.ptr = c->modrm_ptr; 1141 break; 1142 } 1143 c->src.type = OP_MEM; 1144 c->src.ptr = (unsigned long *)c->modrm_ea; 1145 c->src.val = 0; 1146 break; 1147 case SrcImm: 1148 case SrcImmU: 1149 c->src.type = OP_IMM; 1150 c->src.ptr = (unsigned long *)c->eip; 1151 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1152 if (c->src.bytes == 8) 1153 c->src.bytes = 4; 1154 /* NB. Immediates are sign-extended as necessary. */ 1155 switch (c->src.bytes) { 1156 case 1: 1157 c->src.val = insn_fetch(s8, 1, c->eip); 1158 break; 1159 case 2: 1160 c->src.val = insn_fetch(s16, 2, c->eip); 1161 break; 1162 case 4: 1163 c->src.val = insn_fetch(s32, 4, c->eip); 1164 break; 1165 } 1166 if ((c->d & SrcMask) == SrcImmU) { 1167 switch (c->src.bytes) { 1168 case 1: 1169 c->src.val &= 0xff; 1170 break; 1171 case 2: 1172 c->src.val &= 0xffff; 1173 break; 1174 case 4: 1175 c->src.val &= 0xffffffff; 1176 break; 1177 } 1178 } 1179 break; 1180 case SrcImmByte: 1181 case SrcImmUByte: 1182 c->src.type = OP_IMM; 1183 c->src.ptr = (unsigned long *)c->eip; 1184 c->src.bytes = 1; 1185 if ((c->d & SrcMask) == SrcImmByte) 1186 c->src.val = insn_fetch(s8, 1, c->eip); 1187 else 1188 c->src.val = insn_fetch(u8, 1, c->eip); 1189 break; 1190 case SrcAcc: 1191 c->src.type = OP_REG; 1192 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1193 c->src.ptr = &c->regs[VCPU_REGS_RAX]; 1194 switch (c->src.bytes) { 1195 case 1: 1196 c->src.val = *(u8 *)c->src.ptr; 1197 break; 1198 case 2: 1199 c->src.val = *(u16 *)c->src.ptr; 1200 break; 1201 case 4: 1202 c->src.val = *(u32 *)c->src.ptr; 1203 break; 1204 case 8: 1205 c->src.val = *(u64 *)c->src.ptr; 1206 break; 1207 } 1208 break; 1209 case SrcOne: 1210 c->src.bytes = 1; 1211 c->src.val = 1; 1212 break; 1213 case SrcSI: 1214 c->src.type = OP_MEM; 1215 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1216 c->src.ptr = (unsigned long *) 1217 register_address(c, seg_override_base(ctxt, ops, c), 1218 c->regs[VCPU_REGS_RSI]); 1219 c->src.val = 0; 1220 break; 1221 case SrcImmFAddr: 1222 c->src.type = OP_IMM; 1223 c->src.ptr = (unsigned long *)c->eip; 1224 c->src.bytes = c->op_bytes + 2; 1225 insn_fetch_arr(c->src.valptr, c->src.bytes, c->eip); 1226 break; 1227 case SrcMemFAddr: 1228 c->src.type = OP_MEM; 1229 c->src.ptr = (unsigned long *)c->modrm_ea; 1230 c->src.bytes = c->op_bytes + 2; 1231 break; 1232 } 1233 1234 /* 1235 * Decode and fetch the second source operand: register, memory 1236 * or immediate. 1237 */ 1238 switch (c->d & Src2Mask) { 1239 case Src2None: 1240 break; 1241 case Src2CL: 1242 c->src2.bytes = 1; 1243 c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8; 1244 break; 1245 case Src2ImmByte: 1246 c->src2.type = OP_IMM; 1247 c->src2.ptr = (unsigned long *)c->eip; 1248 c->src2.bytes = 1; 1249 c->src2.val = insn_fetch(u8, 1, c->eip); 1250 break; 1251 case Src2One: 1252 c->src2.bytes = 1; 1253 c->src2.val = 1; 1254 break; 1255 } 1256 1257 /* Decode and fetch the destination operand: register or memory. */ 1258 switch (c->d & DstMask) { 1259 case ImplicitOps: 1260 /* Special instructions do their own operand decoding. */ 1261 return 0; 1262 case DstReg: 1263 decode_register_operand(&c->dst, c, 1264 c->twobyte && (c->b == 0xb6 || c->b == 0xb7)); 1265 break; 1266 case DstMem: 1267 case DstMem64: 1268 if ((c->d & ModRM) && c->modrm_mod == 3) { 1269 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1270 c->dst.type = OP_REG; 1271 c->dst.val = c->dst.orig_val = c->modrm_val; 1272 c->dst.ptr = c->modrm_ptr; 1273 break; 1274 } 1275 c->dst.type = OP_MEM; 1276 c->dst.ptr = (unsigned long *)c->modrm_ea; 1277 if ((c->d & DstMask) == DstMem64) 1278 c->dst.bytes = 8; 1279 else 1280 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1281 c->dst.val = 0; 1282 if (c->d & BitOp) { 1283 unsigned long mask = ~(c->dst.bytes * 8 - 1); 1284 1285 c->dst.ptr = (void *)c->dst.ptr + 1286 (c->src.val & mask) / 8; 1287 } 1288 break; 1289 case DstAcc: 1290 c->dst.type = OP_REG; 1291 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1292 c->dst.ptr = &c->regs[VCPU_REGS_RAX]; 1293 switch (c->dst.bytes) { 1294 case 1: 1295 c->dst.val = *(u8 *)c->dst.ptr; 1296 break; 1297 case 2: 1298 c->dst.val = *(u16 *)c->dst.ptr; 1299 break; 1300 case 4: 1301 c->dst.val = *(u32 *)c->dst.ptr; 1302 break; 1303 case 8: 1304 c->dst.val = *(u64 *)c->dst.ptr; 1305 break; 1306 } 1307 c->dst.orig_val = c->dst.val; 1308 break; 1309 case DstDI: 1310 c->dst.type = OP_MEM; 1311 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 1312 c->dst.ptr = (unsigned long *) 1313 register_address(c, es_base(ctxt, ops), 1314 c->regs[VCPU_REGS_RDI]); 1315 c->dst.val = 0; 1316 break; 1317 } 1318 1319 done: 1320 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; 1321 } 1322 1323 static int read_emulated(struct x86_emulate_ctxt *ctxt, 1324 struct x86_emulate_ops *ops, 1325 unsigned long addr, void *dest, unsigned size) 1326 { 1327 int rc; 1328 struct read_cache *mc = &ctxt->decode.mem_read; 1329 u32 err; 1330 1331 while (size) { 1332 int n = min(size, 8u); 1333 size -= n; 1334 if (mc->pos < mc->end) 1335 goto read_cached; 1336 1337 rc = ops->read_emulated(addr, mc->data + mc->end, n, &err, 1338 ctxt->vcpu); 1339 if (rc == X86EMUL_PROPAGATE_FAULT) 1340 emulate_pf(ctxt, addr, err); 1341 if (rc != X86EMUL_CONTINUE) 1342 return rc; 1343 mc->end += n; 1344 1345 read_cached: 1346 memcpy(dest, mc->data + mc->pos, n); 1347 mc->pos += n; 1348 dest += n; 1349 addr += n; 1350 } 1351 return X86EMUL_CONTINUE; 1352 } 1353 1354 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, 1355 struct x86_emulate_ops *ops, 1356 unsigned int size, unsigned short port, 1357 void *dest) 1358 { 1359 struct read_cache *rc = &ctxt->decode.io_read; 1360 1361 if (rc->pos == rc->end) { /* refill pio read ahead */ 1362 struct decode_cache *c = &ctxt->decode; 1363 unsigned int in_page, n; 1364 unsigned int count = c->rep_prefix ? 1365 address_mask(c, c->regs[VCPU_REGS_RCX]) : 1; 1366 in_page = (ctxt->eflags & EFLG_DF) ? 1367 offset_in_page(c->regs[VCPU_REGS_RDI]) : 1368 PAGE_SIZE - offset_in_page(c->regs[VCPU_REGS_RDI]); 1369 n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size, 1370 count); 1371 if (n == 0) 1372 n = 1; 1373 rc->pos = rc->end = 0; 1374 if (!ops->pio_in_emulated(size, port, rc->data, n, ctxt->vcpu)) 1375 return 0; 1376 rc->end = n * size; 1377 } 1378 1379 memcpy(dest, rc->data + rc->pos, size); 1380 rc->pos += size; 1381 return 1; 1382 } 1383 1384 static u32 desc_limit_scaled(struct desc_struct *desc) 1385 { 1386 u32 limit = get_desc_limit(desc); 1387 1388 return desc->g ? (limit << 12) | 0xfff : limit; 1389 } 1390 1391 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, 1392 struct x86_emulate_ops *ops, 1393 u16 selector, struct desc_ptr *dt) 1394 { 1395 if (selector & 1 << 2) { 1396 struct desc_struct desc; 1397 memset (dt, 0, sizeof *dt); 1398 if (!ops->get_cached_descriptor(&desc, VCPU_SREG_LDTR, ctxt->vcpu)) 1399 return; 1400 1401 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ 1402 dt->address = get_desc_base(&desc); 1403 } else 1404 ops->get_gdt(dt, ctxt->vcpu); 1405 } 1406 1407 /* allowed just for 8 bytes segments */ 1408 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1409 struct x86_emulate_ops *ops, 1410 u16 selector, struct desc_struct *desc) 1411 { 1412 struct desc_ptr dt; 1413 u16 index = selector >> 3; 1414 int ret; 1415 u32 err; 1416 ulong addr; 1417 1418 get_descriptor_table_ptr(ctxt, ops, selector, &dt); 1419 1420 if (dt.size < index * 8 + 7) { 1421 emulate_gp(ctxt, selector & 0xfffc); 1422 return X86EMUL_PROPAGATE_FAULT; 1423 } 1424 addr = dt.address + index * 8; 1425 ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu, &err); 1426 if (ret == X86EMUL_PROPAGATE_FAULT) 1427 emulate_pf(ctxt, addr, err); 1428 1429 return ret; 1430 } 1431 1432 /* allowed just for 8 bytes segments */ 1433 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1434 struct x86_emulate_ops *ops, 1435 u16 selector, struct desc_struct *desc) 1436 { 1437 struct desc_ptr dt; 1438 u16 index = selector >> 3; 1439 u32 err; 1440 ulong addr; 1441 int ret; 1442 1443 get_descriptor_table_ptr(ctxt, ops, selector, &dt); 1444 1445 if (dt.size < index * 8 + 7) { 1446 emulate_gp(ctxt, selector & 0xfffc); 1447 return X86EMUL_PROPAGATE_FAULT; 1448 } 1449 1450 addr = dt.address + index * 8; 1451 ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu, &err); 1452 if (ret == X86EMUL_PROPAGATE_FAULT) 1453 emulate_pf(ctxt, addr, err); 1454 1455 return ret; 1456 } 1457 1458 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1459 struct x86_emulate_ops *ops, 1460 u16 selector, int seg) 1461 { 1462 struct desc_struct seg_desc; 1463 u8 dpl, rpl, cpl; 1464 unsigned err_vec = GP_VECTOR; 1465 u32 err_code = 0; 1466 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ 1467 int ret; 1468 1469 memset(&seg_desc, 0, sizeof seg_desc); 1470 1471 if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) 1472 || ctxt->mode == X86EMUL_MODE_REAL) { 1473 /* set real mode segment descriptor */ 1474 set_desc_base(&seg_desc, selector << 4); 1475 set_desc_limit(&seg_desc, 0xffff); 1476 seg_desc.type = 3; 1477 seg_desc.p = 1; 1478 seg_desc.s = 1; 1479 goto load; 1480 } 1481 1482 /* NULL selector is not valid for TR, CS and SS */ 1483 if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR) 1484 && null_selector) 1485 goto exception; 1486 1487 /* TR should be in GDT only */ 1488 if (seg == VCPU_SREG_TR && (selector & (1 << 2))) 1489 goto exception; 1490 1491 if (null_selector) /* for NULL selector skip all following checks */ 1492 goto load; 1493 1494 ret = read_segment_descriptor(ctxt, ops, selector, &seg_desc); 1495 if (ret != X86EMUL_CONTINUE) 1496 return ret; 1497 1498 err_code = selector & 0xfffc; 1499 err_vec = GP_VECTOR; 1500 1501 /* can't load system descriptor into segment selecor */ 1502 if (seg <= VCPU_SREG_GS && !seg_desc.s) 1503 goto exception; 1504 1505 if (!seg_desc.p) { 1506 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; 1507 goto exception; 1508 } 1509 1510 rpl = selector & 3; 1511 dpl = seg_desc.dpl; 1512 cpl = ops->cpl(ctxt->vcpu); 1513 1514 switch (seg) { 1515 case VCPU_SREG_SS: 1516 /* 1517 * segment is not a writable data segment or segment 1518 * selector's RPL != CPL or segment selector's RPL != CPL 1519 */ 1520 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) 1521 goto exception; 1522 break; 1523 case VCPU_SREG_CS: 1524 if (!(seg_desc.type & 8)) 1525 goto exception; 1526 1527 if (seg_desc.type & 4) { 1528 /* conforming */ 1529 if (dpl > cpl) 1530 goto exception; 1531 } else { 1532 /* nonconforming */ 1533 if (rpl > cpl || dpl != cpl) 1534 goto exception; 1535 } 1536 /* CS(RPL) <- CPL */ 1537 selector = (selector & 0xfffc) | cpl; 1538 break; 1539 case VCPU_SREG_TR: 1540 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) 1541 goto exception; 1542 break; 1543 case VCPU_SREG_LDTR: 1544 if (seg_desc.s || seg_desc.type != 2) 1545 goto exception; 1546 break; 1547 default: /* DS, ES, FS, or GS */ 1548 /* 1549 * segment is not a data or readable code segment or 1550 * ((segment is a data or nonconforming code segment) 1551 * and (both RPL and CPL > DPL)) 1552 */ 1553 if ((seg_desc.type & 0xa) == 0x8 || 1554 (((seg_desc.type & 0xc) != 0xc) && 1555 (rpl > dpl && cpl > dpl))) 1556 goto exception; 1557 break; 1558 } 1559 1560 if (seg_desc.s) { 1561 /* mark segment as accessed */ 1562 seg_desc.type |= 1; 1563 ret = write_segment_descriptor(ctxt, ops, selector, &seg_desc); 1564 if (ret != X86EMUL_CONTINUE) 1565 return ret; 1566 } 1567 load: 1568 ops->set_segment_selector(selector, seg, ctxt->vcpu); 1569 ops->set_cached_descriptor(&seg_desc, seg, ctxt->vcpu); 1570 return X86EMUL_CONTINUE; 1571 exception: 1572 emulate_exception(ctxt, err_vec, err_code, true); 1573 return X86EMUL_PROPAGATE_FAULT; 1574 } 1575 1576 static inline int writeback(struct x86_emulate_ctxt *ctxt, 1577 struct x86_emulate_ops *ops) 1578 { 1579 int rc; 1580 struct decode_cache *c = &ctxt->decode; 1581 u32 err; 1582 1583 switch (c->dst.type) { 1584 case OP_REG: 1585 /* The 4-byte case *is* correct: 1586 * in 64-bit mode we zero-extend. 1587 */ 1588 switch (c->dst.bytes) { 1589 case 1: 1590 *(u8 *)c->dst.ptr = (u8)c->dst.val; 1591 break; 1592 case 2: 1593 *(u16 *)c->dst.ptr = (u16)c->dst.val; 1594 break; 1595 case 4: 1596 *c->dst.ptr = (u32)c->dst.val; 1597 break; /* 64b: zero-ext */ 1598 case 8: 1599 *c->dst.ptr = c->dst.val; 1600 break; 1601 } 1602 break; 1603 case OP_MEM: 1604 if (c->lock_prefix) 1605 rc = ops->cmpxchg_emulated( 1606 (unsigned long)c->dst.ptr, 1607 &c->dst.orig_val, 1608 &c->dst.val, 1609 c->dst.bytes, 1610 &err, 1611 ctxt->vcpu); 1612 else 1613 rc = ops->write_emulated( 1614 (unsigned long)c->dst.ptr, 1615 &c->dst.val, 1616 c->dst.bytes, 1617 &err, 1618 ctxt->vcpu); 1619 if (rc == X86EMUL_PROPAGATE_FAULT) 1620 emulate_pf(ctxt, 1621 (unsigned long)c->dst.ptr, err); 1622 if (rc != X86EMUL_CONTINUE) 1623 return rc; 1624 break; 1625 case OP_NONE: 1626 /* no writeback */ 1627 break; 1628 default: 1629 break; 1630 } 1631 return X86EMUL_CONTINUE; 1632 } 1633 1634 static inline void emulate_push(struct x86_emulate_ctxt *ctxt, 1635 struct x86_emulate_ops *ops) 1636 { 1637 struct decode_cache *c = &ctxt->decode; 1638 1639 c->dst.type = OP_MEM; 1640 c->dst.bytes = c->op_bytes; 1641 c->dst.val = c->src.val; 1642 register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes); 1643 c->dst.ptr = (void *) register_address(c, ss_base(ctxt, ops), 1644 c->regs[VCPU_REGS_RSP]); 1645 } 1646 1647 static int emulate_pop(struct x86_emulate_ctxt *ctxt, 1648 struct x86_emulate_ops *ops, 1649 void *dest, int len) 1650 { 1651 struct decode_cache *c = &ctxt->decode; 1652 int rc; 1653 1654 rc = read_emulated(ctxt, ops, register_address(c, ss_base(ctxt, ops), 1655 c->regs[VCPU_REGS_RSP]), 1656 dest, len); 1657 if (rc != X86EMUL_CONTINUE) 1658 return rc; 1659 1660 register_address_increment(c, &c->regs[VCPU_REGS_RSP], len); 1661 return rc; 1662 } 1663 1664 static int emulate_popf(struct x86_emulate_ctxt *ctxt, 1665 struct x86_emulate_ops *ops, 1666 void *dest, int len) 1667 { 1668 int rc; 1669 unsigned long val, change_mask; 1670 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; 1671 int cpl = ops->cpl(ctxt->vcpu); 1672 1673 rc = emulate_pop(ctxt, ops, &val, len); 1674 if (rc != X86EMUL_CONTINUE) 1675 return rc; 1676 1677 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF 1678 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID; 1679 1680 switch(ctxt->mode) { 1681 case X86EMUL_MODE_PROT64: 1682 case X86EMUL_MODE_PROT32: 1683 case X86EMUL_MODE_PROT16: 1684 if (cpl == 0) 1685 change_mask |= EFLG_IOPL; 1686 if (cpl <= iopl) 1687 change_mask |= EFLG_IF; 1688 break; 1689 case X86EMUL_MODE_VM86: 1690 if (iopl < 3) { 1691 emulate_gp(ctxt, 0); 1692 return X86EMUL_PROPAGATE_FAULT; 1693 } 1694 change_mask |= EFLG_IF; 1695 break; 1696 default: /* real mode */ 1697 change_mask |= (EFLG_IOPL | EFLG_IF); 1698 break; 1699 } 1700 1701 *(unsigned long *)dest = 1702 (ctxt->eflags & ~change_mask) | (val & change_mask); 1703 1704 return rc; 1705 } 1706 1707 static void emulate_push_sreg(struct x86_emulate_ctxt *ctxt, 1708 struct x86_emulate_ops *ops, int seg) 1709 { 1710 struct decode_cache *c = &ctxt->decode; 1711 1712 c->src.val = ops->get_segment_selector(seg, ctxt->vcpu); 1713 1714 emulate_push(ctxt, ops); 1715 } 1716 1717 static int emulate_pop_sreg(struct x86_emulate_ctxt *ctxt, 1718 struct x86_emulate_ops *ops, int seg) 1719 { 1720 struct decode_cache *c = &ctxt->decode; 1721 unsigned long selector; 1722 int rc; 1723 1724 rc = emulate_pop(ctxt, ops, &selector, c->op_bytes); 1725 if (rc != X86EMUL_CONTINUE) 1726 return rc; 1727 1728 rc = load_segment_descriptor(ctxt, ops, (u16)selector, seg); 1729 return rc; 1730 } 1731 1732 static int emulate_pusha(struct x86_emulate_ctxt *ctxt, 1733 struct x86_emulate_ops *ops) 1734 { 1735 struct decode_cache *c = &ctxt->decode; 1736 unsigned long old_esp = c->regs[VCPU_REGS_RSP]; 1737 int rc = X86EMUL_CONTINUE; 1738 int reg = VCPU_REGS_RAX; 1739 1740 while (reg <= VCPU_REGS_RDI) { 1741 (reg == VCPU_REGS_RSP) ? 1742 (c->src.val = old_esp) : (c->src.val = c->regs[reg]); 1743 1744 emulate_push(ctxt, ops); 1745 1746 rc = writeback(ctxt, ops); 1747 if (rc != X86EMUL_CONTINUE) 1748 return rc; 1749 1750 ++reg; 1751 } 1752 1753 /* Disable writeback. */ 1754 c->dst.type = OP_NONE; 1755 1756 return rc; 1757 } 1758 1759 static int emulate_popa(struct x86_emulate_ctxt *ctxt, 1760 struct x86_emulate_ops *ops) 1761 { 1762 struct decode_cache *c = &ctxt->decode; 1763 int rc = X86EMUL_CONTINUE; 1764 int reg = VCPU_REGS_RDI; 1765 1766 while (reg >= VCPU_REGS_RAX) { 1767 if (reg == VCPU_REGS_RSP) { 1768 register_address_increment(c, &c->regs[VCPU_REGS_RSP], 1769 c->op_bytes); 1770 --reg; 1771 } 1772 1773 rc = emulate_pop(ctxt, ops, &c->regs[reg], c->op_bytes); 1774 if (rc != X86EMUL_CONTINUE) 1775 break; 1776 --reg; 1777 } 1778 return rc; 1779 } 1780 1781 static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt, 1782 struct x86_emulate_ops *ops) 1783 { 1784 struct decode_cache *c = &ctxt->decode; 1785 1786 return emulate_pop(ctxt, ops, &c->dst.val, c->dst.bytes); 1787 } 1788 1789 static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt) 1790 { 1791 struct decode_cache *c = &ctxt->decode; 1792 switch (c->modrm_reg) { 1793 case 0: /* rol */ 1794 emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags); 1795 break; 1796 case 1: /* ror */ 1797 emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags); 1798 break; 1799 case 2: /* rcl */ 1800 emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags); 1801 break; 1802 case 3: /* rcr */ 1803 emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags); 1804 break; 1805 case 4: /* sal/shl */ 1806 case 6: /* sal/shl */ 1807 emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags); 1808 break; 1809 case 5: /* shr */ 1810 emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags); 1811 break; 1812 case 7: /* sar */ 1813 emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags); 1814 break; 1815 } 1816 } 1817 1818 static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt, 1819 struct x86_emulate_ops *ops) 1820 { 1821 struct decode_cache *c = &ctxt->decode; 1822 1823 switch (c->modrm_reg) { 1824 case 0 ... 1: /* test */ 1825 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); 1826 break; 1827 case 2: /* not */ 1828 c->dst.val = ~c->dst.val; 1829 break; 1830 case 3: /* neg */ 1831 emulate_1op("neg", c->dst, ctxt->eflags); 1832 break; 1833 default: 1834 return 0; 1835 } 1836 return 1; 1837 } 1838 1839 static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt, 1840 struct x86_emulate_ops *ops) 1841 { 1842 struct decode_cache *c = &ctxt->decode; 1843 1844 switch (c->modrm_reg) { 1845 case 0: /* inc */ 1846 emulate_1op("inc", c->dst, ctxt->eflags); 1847 break; 1848 case 1: /* dec */ 1849 emulate_1op("dec", c->dst, ctxt->eflags); 1850 break; 1851 case 2: /* call near abs */ { 1852 long int old_eip; 1853 old_eip = c->eip; 1854 c->eip = c->src.val; 1855 c->src.val = old_eip; 1856 emulate_push(ctxt, ops); 1857 break; 1858 } 1859 case 4: /* jmp abs */ 1860 c->eip = c->src.val; 1861 break; 1862 case 6: /* push */ 1863 emulate_push(ctxt, ops); 1864 break; 1865 } 1866 return X86EMUL_CONTINUE; 1867 } 1868 1869 static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt, 1870 struct x86_emulate_ops *ops) 1871 { 1872 struct decode_cache *c = &ctxt->decode; 1873 u64 old = c->dst.orig_val; 1874 1875 if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) || 1876 ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) { 1877 1878 c->regs[VCPU_REGS_RAX] = (u32) (old >> 0); 1879 c->regs[VCPU_REGS_RDX] = (u32) (old >> 32); 1880 ctxt->eflags &= ~EFLG_ZF; 1881 } else { 1882 c->dst.val = ((u64)c->regs[VCPU_REGS_RCX] << 32) | 1883 (u32) c->regs[VCPU_REGS_RBX]; 1884 1885 ctxt->eflags |= EFLG_ZF; 1886 } 1887 return X86EMUL_CONTINUE; 1888 } 1889 1890 static int emulate_ret_far(struct x86_emulate_ctxt *ctxt, 1891 struct x86_emulate_ops *ops) 1892 { 1893 struct decode_cache *c = &ctxt->decode; 1894 int rc; 1895 unsigned long cs; 1896 1897 rc = emulate_pop(ctxt, ops, &c->eip, c->op_bytes); 1898 if (rc != X86EMUL_CONTINUE) 1899 return rc; 1900 if (c->op_bytes == 4) 1901 c->eip = (u32)c->eip; 1902 rc = emulate_pop(ctxt, ops, &cs, c->op_bytes); 1903 if (rc != X86EMUL_CONTINUE) 1904 return rc; 1905 rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS); 1906 return rc; 1907 } 1908 1909 static inline void 1910 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, 1911 struct x86_emulate_ops *ops, struct desc_struct *cs, 1912 struct desc_struct *ss) 1913 { 1914 memset(cs, 0, sizeof(struct desc_struct)); 1915 ops->get_cached_descriptor(cs, VCPU_SREG_CS, ctxt->vcpu); 1916 memset(ss, 0, sizeof(struct desc_struct)); 1917 1918 cs->l = 0; /* will be adjusted later */ 1919 set_desc_base(cs, 0); /* flat segment */ 1920 cs->g = 1; /* 4kb granularity */ 1921 set_desc_limit(cs, 0xfffff); /* 4GB limit */ 1922 cs->type = 0x0b; /* Read, Execute, Accessed */ 1923 cs->s = 1; 1924 cs->dpl = 0; /* will be adjusted later */ 1925 cs->p = 1; 1926 cs->d = 1; 1927 1928 set_desc_base(ss, 0); /* flat segment */ 1929 set_desc_limit(ss, 0xfffff); /* 4GB limit */ 1930 ss->g = 1; /* 4kb granularity */ 1931 ss->s = 1; 1932 ss->type = 0x03; /* Read/Write, Accessed */ 1933 ss->d = 1; /* 32bit stack segment */ 1934 ss->dpl = 0; 1935 ss->p = 1; 1936 } 1937 1938 static int 1939 emulate_syscall(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 1940 { 1941 struct decode_cache *c = &ctxt->decode; 1942 struct desc_struct cs, ss; 1943 u64 msr_data; 1944 u16 cs_sel, ss_sel; 1945 1946 /* syscall is not available in real mode */ 1947 if (ctxt->mode == X86EMUL_MODE_REAL || 1948 ctxt->mode == X86EMUL_MODE_VM86) { 1949 emulate_ud(ctxt); 1950 return X86EMUL_PROPAGATE_FAULT; 1951 } 1952 1953 setup_syscalls_segments(ctxt, ops, &cs, &ss); 1954 1955 ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data); 1956 msr_data >>= 32; 1957 cs_sel = (u16)(msr_data & 0xfffc); 1958 ss_sel = (u16)(msr_data + 8); 1959 1960 if (is_long_mode(ctxt->vcpu)) { 1961 cs.d = 0; 1962 cs.l = 1; 1963 } 1964 ops->set_cached_descriptor(&cs, VCPU_SREG_CS, ctxt->vcpu); 1965 ops->set_segment_selector(cs_sel, VCPU_SREG_CS, ctxt->vcpu); 1966 ops->set_cached_descriptor(&ss, VCPU_SREG_SS, ctxt->vcpu); 1967 ops->set_segment_selector(ss_sel, VCPU_SREG_SS, ctxt->vcpu); 1968 1969 c->regs[VCPU_REGS_RCX] = c->eip; 1970 if (is_long_mode(ctxt->vcpu)) { 1971 #ifdef CONFIG_X86_64 1972 c->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF; 1973 1974 ops->get_msr(ctxt->vcpu, 1975 ctxt->mode == X86EMUL_MODE_PROT64 ? 1976 MSR_LSTAR : MSR_CSTAR, &msr_data); 1977 c->eip = msr_data; 1978 1979 ops->get_msr(ctxt->vcpu, MSR_SYSCALL_MASK, &msr_data); 1980 ctxt->eflags &= ~(msr_data | EFLG_RF); 1981 #endif 1982 } else { 1983 /* legacy mode */ 1984 ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data); 1985 c->eip = (u32)msr_data; 1986 1987 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); 1988 } 1989 1990 return X86EMUL_CONTINUE; 1991 } 1992 1993 static int 1994 emulate_sysenter(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 1995 { 1996 struct decode_cache *c = &ctxt->decode; 1997 struct desc_struct cs, ss; 1998 u64 msr_data; 1999 u16 cs_sel, ss_sel; 2000 2001 /* inject #GP if in real mode */ 2002 if (ctxt->mode == X86EMUL_MODE_REAL) { 2003 emulate_gp(ctxt, 0); 2004 return X86EMUL_PROPAGATE_FAULT; 2005 } 2006 2007 /* XXX sysenter/sysexit have not been tested in 64bit mode. 2008 * Therefore, we inject an #UD. 2009 */ 2010 if (ctxt->mode == X86EMUL_MODE_PROT64) { 2011 emulate_ud(ctxt); 2012 return X86EMUL_PROPAGATE_FAULT; 2013 } 2014 2015 setup_syscalls_segments(ctxt, ops, &cs, &ss); 2016 2017 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data); 2018 switch (ctxt->mode) { 2019 case X86EMUL_MODE_PROT32: 2020 if ((msr_data & 0xfffc) == 0x0) { 2021 emulate_gp(ctxt, 0); 2022 return X86EMUL_PROPAGATE_FAULT; 2023 } 2024 break; 2025 case X86EMUL_MODE_PROT64: 2026 if (msr_data == 0x0) { 2027 emulate_gp(ctxt, 0); 2028 return X86EMUL_PROPAGATE_FAULT; 2029 } 2030 break; 2031 } 2032 2033 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); 2034 cs_sel = (u16)msr_data; 2035 cs_sel &= ~SELECTOR_RPL_MASK; 2036 ss_sel = cs_sel + 8; 2037 ss_sel &= ~SELECTOR_RPL_MASK; 2038 if (ctxt->mode == X86EMUL_MODE_PROT64 2039 || is_long_mode(ctxt->vcpu)) { 2040 cs.d = 0; 2041 cs.l = 1; 2042 } 2043 2044 ops->set_cached_descriptor(&cs, VCPU_SREG_CS, ctxt->vcpu); 2045 ops->set_segment_selector(cs_sel, VCPU_SREG_CS, ctxt->vcpu); 2046 ops->set_cached_descriptor(&ss, VCPU_SREG_SS, ctxt->vcpu); 2047 ops->set_segment_selector(ss_sel, VCPU_SREG_SS, ctxt->vcpu); 2048 2049 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_EIP, &msr_data); 2050 c->eip = msr_data; 2051 2052 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_ESP, &msr_data); 2053 c->regs[VCPU_REGS_RSP] = msr_data; 2054 2055 return X86EMUL_CONTINUE; 2056 } 2057 2058 static int 2059 emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 2060 { 2061 struct decode_cache *c = &ctxt->decode; 2062 struct desc_struct cs, ss; 2063 u64 msr_data; 2064 int usermode; 2065 u16 cs_sel, ss_sel; 2066 2067 /* inject #GP if in real mode or Virtual 8086 mode */ 2068 if (ctxt->mode == X86EMUL_MODE_REAL || 2069 ctxt->mode == X86EMUL_MODE_VM86) { 2070 emulate_gp(ctxt, 0); 2071 return X86EMUL_PROPAGATE_FAULT; 2072 } 2073 2074 setup_syscalls_segments(ctxt, ops, &cs, &ss); 2075 2076 if ((c->rex_prefix & 0x8) != 0x0) 2077 usermode = X86EMUL_MODE_PROT64; 2078 else 2079 usermode = X86EMUL_MODE_PROT32; 2080 2081 cs.dpl = 3; 2082 ss.dpl = 3; 2083 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data); 2084 switch (usermode) { 2085 case X86EMUL_MODE_PROT32: 2086 cs_sel = (u16)(msr_data + 16); 2087 if ((msr_data & 0xfffc) == 0x0) { 2088 emulate_gp(ctxt, 0); 2089 return X86EMUL_PROPAGATE_FAULT; 2090 } 2091 ss_sel = (u16)(msr_data + 24); 2092 break; 2093 case X86EMUL_MODE_PROT64: 2094 cs_sel = (u16)(msr_data + 32); 2095 if (msr_data == 0x0) { 2096 emulate_gp(ctxt, 0); 2097 return X86EMUL_PROPAGATE_FAULT; 2098 } 2099 ss_sel = cs_sel + 8; 2100 cs.d = 0; 2101 cs.l = 1; 2102 break; 2103 } 2104 cs_sel |= SELECTOR_RPL_MASK; 2105 ss_sel |= SELECTOR_RPL_MASK; 2106 2107 ops->set_cached_descriptor(&cs, VCPU_SREG_CS, ctxt->vcpu); 2108 ops->set_segment_selector(cs_sel, VCPU_SREG_CS, ctxt->vcpu); 2109 ops->set_cached_descriptor(&ss, VCPU_SREG_SS, ctxt->vcpu); 2110 ops->set_segment_selector(ss_sel, VCPU_SREG_SS, ctxt->vcpu); 2111 2112 c->eip = c->regs[VCPU_REGS_RDX]; 2113 c->regs[VCPU_REGS_RSP] = c->regs[VCPU_REGS_RCX]; 2114 2115 return X86EMUL_CONTINUE; 2116 } 2117 2118 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt, 2119 struct x86_emulate_ops *ops) 2120 { 2121 int iopl; 2122 if (ctxt->mode == X86EMUL_MODE_REAL) 2123 return false; 2124 if (ctxt->mode == X86EMUL_MODE_VM86) 2125 return true; 2126 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; 2127 return ops->cpl(ctxt->vcpu) > iopl; 2128 } 2129 2130 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, 2131 struct x86_emulate_ops *ops, 2132 u16 port, u16 len) 2133 { 2134 struct desc_struct tr_seg; 2135 int r; 2136 u16 io_bitmap_ptr; 2137 u8 perm, bit_idx = port & 0x7; 2138 unsigned mask = (1 << len) - 1; 2139 2140 ops->get_cached_descriptor(&tr_seg, VCPU_SREG_TR, ctxt->vcpu); 2141 if (!tr_seg.p) 2142 return false; 2143 if (desc_limit_scaled(&tr_seg) < 103) 2144 return false; 2145 r = ops->read_std(get_desc_base(&tr_seg) + 102, &io_bitmap_ptr, 2, 2146 ctxt->vcpu, NULL); 2147 if (r != X86EMUL_CONTINUE) 2148 return false; 2149 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg)) 2150 return false; 2151 r = ops->read_std(get_desc_base(&tr_seg) + io_bitmap_ptr + port/8, 2152 &perm, 1, ctxt->vcpu, NULL); 2153 if (r != X86EMUL_CONTINUE) 2154 return false; 2155 if ((perm >> bit_idx) & mask) 2156 return false; 2157 return true; 2158 } 2159 2160 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, 2161 struct x86_emulate_ops *ops, 2162 u16 port, u16 len) 2163 { 2164 if (emulator_bad_iopl(ctxt, ops)) 2165 if (!emulator_io_port_access_allowed(ctxt, ops, port, len)) 2166 return false; 2167 return true; 2168 } 2169 2170 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, 2171 struct x86_emulate_ops *ops, 2172 struct tss_segment_16 *tss) 2173 { 2174 struct decode_cache *c = &ctxt->decode; 2175 2176 tss->ip = c->eip; 2177 tss->flag = ctxt->eflags; 2178 tss->ax = c->regs[VCPU_REGS_RAX]; 2179 tss->cx = c->regs[VCPU_REGS_RCX]; 2180 tss->dx = c->regs[VCPU_REGS_RDX]; 2181 tss->bx = c->regs[VCPU_REGS_RBX]; 2182 tss->sp = c->regs[VCPU_REGS_RSP]; 2183 tss->bp = c->regs[VCPU_REGS_RBP]; 2184 tss->si = c->regs[VCPU_REGS_RSI]; 2185 tss->di = c->regs[VCPU_REGS_RDI]; 2186 2187 tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu); 2188 tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu); 2189 tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu); 2190 tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu); 2191 tss->ldt = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu); 2192 } 2193 2194 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, 2195 struct x86_emulate_ops *ops, 2196 struct tss_segment_16 *tss) 2197 { 2198 struct decode_cache *c = &ctxt->decode; 2199 int ret; 2200 2201 c->eip = tss->ip; 2202 ctxt->eflags = tss->flag | 2; 2203 c->regs[VCPU_REGS_RAX] = tss->ax; 2204 c->regs[VCPU_REGS_RCX] = tss->cx; 2205 c->regs[VCPU_REGS_RDX] = tss->dx; 2206 c->regs[VCPU_REGS_RBX] = tss->bx; 2207 c->regs[VCPU_REGS_RSP] = tss->sp; 2208 c->regs[VCPU_REGS_RBP] = tss->bp; 2209 c->regs[VCPU_REGS_RSI] = tss->si; 2210 c->regs[VCPU_REGS_RDI] = tss->di; 2211 2212 /* 2213 * SDM says that segment selectors are loaded before segment 2214 * descriptors 2215 */ 2216 ops->set_segment_selector(tss->ldt, VCPU_SREG_LDTR, ctxt->vcpu); 2217 ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu); 2218 ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu); 2219 ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu); 2220 ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu); 2221 2222 /* 2223 * Now load segment descriptors. If fault happenes at this stage 2224 * it is handled in a context of new task 2225 */ 2226 ret = load_segment_descriptor(ctxt, ops, tss->ldt, VCPU_SREG_LDTR); 2227 if (ret != X86EMUL_CONTINUE) 2228 return ret; 2229 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES); 2230 if (ret != X86EMUL_CONTINUE) 2231 return ret; 2232 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS); 2233 if (ret != X86EMUL_CONTINUE) 2234 return ret; 2235 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS); 2236 if (ret != X86EMUL_CONTINUE) 2237 return ret; 2238 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS); 2239 if (ret != X86EMUL_CONTINUE) 2240 return ret; 2241 2242 return X86EMUL_CONTINUE; 2243 } 2244 2245 static int task_switch_16(struct x86_emulate_ctxt *ctxt, 2246 struct x86_emulate_ops *ops, 2247 u16 tss_selector, u16 old_tss_sel, 2248 ulong old_tss_base, struct desc_struct *new_desc) 2249 { 2250 struct tss_segment_16 tss_seg; 2251 int ret; 2252 u32 err, new_tss_base = get_desc_base(new_desc); 2253 2254 ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, 2255 &err); 2256 if (ret == X86EMUL_PROPAGATE_FAULT) { 2257 /* FIXME: need to provide precise fault address */ 2258 emulate_pf(ctxt, old_tss_base, err); 2259 return ret; 2260 } 2261 2262 save_state_to_tss16(ctxt, ops, &tss_seg); 2263 2264 ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, 2265 &err); 2266 if (ret == X86EMUL_PROPAGATE_FAULT) { 2267 /* FIXME: need to provide precise fault address */ 2268 emulate_pf(ctxt, old_tss_base, err); 2269 return ret; 2270 } 2271 2272 ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, 2273 &err); 2274 if (ret == X86EMUL_PROPAGATE_FAULT) { 2275 /* FIXME: need to provide precise fault address */ 2276 emulate_pf(ctxt, new_tss_base, err); 2277 return ret; 2278 } 2279 2280 if (old_tss_sel != 0xffff) { 2281 tss_seg.prev_task_link = old_tss_sel; 2282 2283 ret = ops->write_std(new_tss_base, 2284 &tss_seg.prev_task_link, 2285 sizeof tss_seg.prev_task_link, 2286 ctxt->vcpu, &err); 2287 if (ret == X86EMUL_PROPAGATE_FAULT) { 2288 /* FIXME: need to provide precise fault address */ 2289 emulate_pf(ctxt, new_tss_base, err); 2290 return ret; 2291 } 2292 } 2293 2294 return load_state_from_tss16(ctxt, ops, &tss_seg); 2295 } 2296 2297 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, 2298 struct x86_emulate_ops *ops, 2299 struct tss_segment_32 *tss) 2300 { 2301 struct decode_cache *c = &ctxt->decode; 2302 2303 tss->cr3 = ops->get_cr(3, ctxt->vcpu); 2304 tss->eip = c->eip; 2305 tss->eflags = ctxt->eflags; 2306 tss->eax = c->regs[VCPU_REGS_RAX]; 2307 tss->ecx = c->regs[VCPU_REGS_RCX]; 2308 tss->edx = c->regs[VCPU_REGS_RDX]; 2309 tss->ebx = c->regs[VCPU_REGS_RBX]; 2310 tss->esp = c->regs[VCPU_REGS_RSP]; 2311 tss->ebp = c->regs[VCPU_REGS_RBP]; 2312 tss->esi = c->regs[VCPU_REGS_RSI]; 2313 tss->edi = c->regs[VCPU_REGS_RDI]; 2314 2315 tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu); 2316 tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu); 2317 tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu); 2318 tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu); 2319 tss->fs = ops->get_segment_selector(VCPU_SREG_FS, ctxt->vcpu); 2320 tss->gs = ops->get_segment_selector(VCPU_SREG_GS, ctxt->vcpu); 2321 tss->ldt_selector = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu); 2322 } 2323 2324 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, 2325 struct x86_emulate_ops *ops, 2326 struct tss_segment_32 *tss) 2327 { 2328 struct decode_cache *c = &ctxt->decode; 2329 int ret; 2330 2331 if (ops->set_cr(3, tss->cr3, ctxt->vcpu)) { 2332 emulate_gp(ctxt, 0); 2333 return X86EMUL_PROPAGATE_FAULT; 2334 } 2335 c->eip = tss->eip; 2336 ctxt->eflags = tss->eflags | 2; 2337 c->regs[VCPU_REGS_RAX] = tss->eax; 2338 c->regs[VCPU_REGS_RCX] = tss->ecx; 2339 c->regs[VCPU_REGS_RDX] = tss->edx; 2340 c->regs[VCPU_REGS_RBX] = tss->ebx; 2341 c->regs[VCPU_REGS_RSP] = tss->esp; 2342 c->regs[VCPU_REGS_RBP] = tss->ebp; 2343 c->regs[VCPU_REGS_RSI] = tss->esi; 2344 c->regs[VCPU_REGS_RDI] = tss->edi; 2345 2346 /* 2347 * SDM says that segment selectors are loaded before segment 2348 * descriptors 2349 */ 2350 ops->set_segment_selector(tss->ldt_selector, VCPU_SREG_LDTR, ctxt->vcpu); 2351 ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu); 2352 ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu); 2353 ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu); 2354 ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu); 2355 ops->set_segment_selector(tss->fs, VCPU_SREG_FS, ctxt->vcpu); 2356 ops->set_segment_selector(tss->gs, VCPU_SREG_GS, ctxt->vcpu); 2357 2358 /* 2359 * Now load segment descriptors. If fault happenes at this stage 2360 * it is handled in a context of new task 2361 */ 2362 ret = load_segment_descriptor(ctxt, ops, tss->ldt_selector, VCPU_SREG_LDTR); 2363 if (ret != X86EMUL_CONTINUE) 2364 return ret; 2365 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES); 2366 if (ret != X86EMUL_CONTINUE) 2367 return ret; 2368 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS); 2369 if (ret != X86EMUL_CONTINUE) 2370 return ret; 2371 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS); 2372 if (ret != X86EMUL_CONTINUE) 2373 return ret; 2374 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS); 2375 if (ret != X86EMUL_CONTINUE) 2376 return ret; 2377 ret = load_segment_descriptor(ctxt, ops, tss->fs, VCPU_SREG_FS); 2378 if (ret != X86EMUL_CONTINUE) 2379 return ret; 2380 ret = load_segment_descriptor(ctxt, ops, tss->gs, VCPU_SREG_GS); 2381 if (ret != X86EMUL_CONTINUE) 2382 return ret; 2383 2384 return X86EMUL_CONTINUE; 2385 } 2386 2387 static int task_switch_32(struct x86_emulate_ctxt *ctxt, 2388 struct x86_emulate_ops *ops, 2389 u16 tss_selector, u16 old_tss_sel, 2390 ulong old_tss_base, struct desc_struct *new_desc) 2391 { 2392 struct tss_segment_32 tss_seg; 2393 int ret; 2394 u32 err, new_tss_base = get_desc_base(new_desc); 2395 2396 ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, 2397 &err); 2398 if (ret == X86EMUL_PROPAGATE_FAULT) { 2399 /* FIXME: need to provide precise fault address */ 2400 emulate_pf(ctxt, old_tss_base, err); 2401 return ret; 2402 } 2403 2404 save_state_to_tss32(ctxt, ops, &tss_seg); 2405 2406 ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, 2407 &err); 2408 if (ret == X86EMUL_PROPAGATE_FAULT) { 2409 /* FIXME: need to provide precise fault address */ 2410 emulate_pf(ctxt, old_tss_base, err); 2411 return ret; 2412 } 2413 2414 ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu, 2415 &err); 2416 if (ret == X86EMUL_PROPAGATE_FAULT) { 2417 /* FIXME: need to provide precise fault address */ 2418 emulate_pf(ctxt, new_tss_base, err); 2419 return ret; 2420 } 2421 2422 if (old_tss_sel != 0xffff) { 2423 tss_seg.prev_task_link = old_tss_sel; 2424 2425 ret = ops->write_std(new_tss_base, 2426 &tss_seg.prev_task_link, 2427 sizeof tss_seg.prev_task_link, 2428 ctxt->vcpu, &err); 2429 if (ret == X86EMUL_PROPAGATE_FAULT) { 2430 /* FIXME: need to provide precise fault address */ 2431 emulate_pf(ctxt, new_tss_base, err); 2432 return ret; 2433 } 2434 } 2435 2436 return load_state_from_tss32(ctxt, ops, &tss_seg); 2437 } 2438 2439 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, 2440 struct x86_emulate_ops *ops, 2441 u16 tss_selector, int reason, 2442 bool has_error_code, u32 error_code) 2443 { 2444 struct desc_struct curr_tss_desc, next_tss_desc; 2445 int ret; 2446 u16 old_tss_sel = ops->get_segment_selector(VCPU_SREG_TR, ctxt->vcpu); 2447 ulong old_tss_base = 2448 ops->get_cached_segment_base(VCPU_SREG_TR, ctxt->vcpu); 2449 u32 desc_limit; 2450 2451 /* FIXME: old_tss_base == ~0 ? */ 2452 2453 ret = read_segment_descriptor(ctxt, ops, tss_selector, &next_tss_desc); 2454 if (ret != X86EMUL_CONTINUE) 2455 return ret; 2456 ret = read_segment_descriptor(ctxt, ops, old_tss_sel, &curr_tss_desc); 2457 if (ret != X86EMUL_CONTINUE) 2458 return ret; 2459 2460 /* FIXME: check that next_tss_desc is tss */ 2461 2462 if (reason != TASK_SWITCH_IRET) { 2463 if ((tss_selector & 3) > next_tss_desc.dpl || 2464 ops->cpl(ctxt->vcpu) > next_tss_desc.dpl) { 2465 emulate_gp(ctxt, 0); 2466 return X86EMUL_PROPAGATE_FAULT; 2467 } 2468 } 2469 2470 desc_limit = desc_limit_scaled(&next_tss_desc); 2471 if (!next_tss_desc.p || 2472 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || 2473 desc_limit < 0x2b)) { 2474 emulate_ts(ctxt, tss_selector & 0xfffc); 2475 return X86EMUL_PROPAGATE_FAULT; 2476 } 2477 2478 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { 2479 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ 2480 write_segment_descriptor(ctxt, ops, old_tss_sel, 2481 &curr_tss_desc); 2482 } 2483 2484 if (reason == TASK_SWITCH_IRET) 2485 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; 2486 2487 /* set back link to prev task only if NT bit is set in eflags 2488 note that old_tss_sel is not used afetr this point */ 2489 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) 2490 old_tss_sel = 0xffff; 2491 2492 if (next_tss_desc.type & 8) 2493 ret = task_switch_32(ctxt, ops, tss_selector, old_tss_sel, 2494 old_tss_base, &next_tss_desc); 2495 else 2496 ret = task_switch_16(ctxt, ops, tss_selector, old_tss_sel, 2497 old_tss_base, &next_tss_desc); 2498 if (ret != X86EMUL_CONTINUE) 2499 return ret; 2500 2501 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) 2502 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; 2503 2504 if (reason != TASK_SWITCH_IRET) { 2505 next_tss_desc.type |= (1 << 1); /* set busy flag */ 2506 write_segment_descriptor(ctxt, ops, tss_selector, 2507 &next_tss_desc); 2508 } 2509 2510 ops->set_cr(0, ops->get_cr(0, ctxt->vcpu) | X86_CR0_TS, ctxt->vcpu); 2511 ops->set_cached_descriptor(&next_tss_desc, VCPU_SREG_TR, ctxt->vcpu); 2512 ops->set_segment_selector(tss_selector, VCPU_SREG_TR, ctxt->vcpu); 2513 2514 if (has_error_code) { 2515 struct decode_cache *c = &ctxt->decode; 2516 2517 c->op_bytes = c->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; 2518 c->lock_prefix = 0; 2519 c->src.val = (unsigned long) error_code; 2520 emulate_push(ctxt, ops); 2521 } 2522 2523 return ret; 2524 } 2525 2526 int emulator_task_switch(struct x86_emulate_ctxt *ctxt, 2527 struct x86_emulate_ops *ops, 2528 u16 tss_selector, int reason, 2529 bool has_error_code, u32 error_code) 2530 { 2531 struct decode_cache *c = &ctxt->decode; 2532 int rc; 2533 2534 c->eip = ctxt->eip; 2535 c->dst.type = OP_NONE; 2536 2537 rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason, 2538 has_error_code, error_code); 2539 2540 if (rc == X86EMUL_CONTINUE) { 2541 rc = writeback(ctxt, ops); 2542 if (rc == X86EMUL_CONTINUE) 2543 ctxt->eip = c->eip; 2544 } 2545 2546 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; 2547 } 2548 2549 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned long base, 2550 int reg, struct operand *op) 2551 { 2552 struct decode_cache *c = &ctxt->decode; 2553 int df = (ctxt->eflags & EFLG_DF) ? -1 : 1; 2554 2555 register_address_increment(c, &c->regs[reg], df * op->bytes); 2556 op->ptr = (unsigned long *)register_address(c, base, c->regs[reg]); 2557 } 2558 2559 int 2560 x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 2561 { 2562 u64 msr_data; 2563 struct decode_cache *c = &ctxt->decode; 2564 int rc = X86EMUL_CONTINUE; 2565 int saved_dst_type = c->dst.type; 2566 2567 ctxt->decode.mem_read.pos = 0; 2568 2569 if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) { 2570 emulate_ud(ctxt); 2571 goto done; 2572 } 2573 2574 /* LOCK prefix is allowed only with some instructions */ 2575 if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) { 2576 emulate_ud(ctxt); 2577 goto done; 2578 } 2579 2580 /* Privileged instruction can be executed only in CPL=0 */ 2581 if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) { 2582 emulate_gp(ctxt, 0); 2583 goto done; 2584 } 2585 2586 if (c->rep_prefix && (c->d & String)) { 2587 ctxt->restart = true; 2588 /* All REP prefixes have the same first termination condition */ 2589 if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { 2590 string_done: 2591 ctxt->restart = false; 2592 ctxt->eip = c->eip; 2593 goto done; 2594 } 2595 /* The second termination condition only applies for REPE 2596 * and REPNE. Test if the repeat string operation prefix is 2597 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the 2598 * corresponding termination condition according to: 2599 * - if REPE/REPZ and ZF = 0 then done 2600 * - if REPNE/REPNZ and ZF = 1 then done 2601 */ 2602 if ((c->b == 0xa6) || (c->b == 0xa7) || 2603 (c->b == 0xae) || (c->b == 0xaf)) { 2604 if ((c->rep_prefix == REPE_PREFIX) && 2605 ((ctxt->eflags & EFLG_ZF) == 0)) 2606 goto string_done; 2607 if ((c->rep_prefix == REPNE_PREFIX) && 2608 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)) 2609 goto string_done; 2610 } 2611 c->eip = ctxt->eip; 2612 } 2613 2614 if (c->src.type == OP_MEM) { 2615 rc = read_emulated(ctxt, ops, (unsigned long)c->src.ptr, 2616 c->src.valptr, c->src.bytes); 2617 if (rc != X86EMUL_CONTINUE) 2618 goto done; 2619 c->src.orig_val = c->src.val; 2620 } 2621 2622 if (c->src2.type == OP_MEM) { 2623 rc = read_emulated(ctxt, ops, (unsigned long)c->src2.ptr, 2624 &c->src2.val, c->src2.bytes); 2625 if (rc != X86EMUL_CONTINUE) 2626 goto done; 2627 } 2628 2629 if ((c->d & DstMask) == ImplicitOps) 2630 goto special_insn; 2631 2632 2633 if ((c->dst.type == OP_MEM) && !(c->d & Mov)) { 2634 /* optimisation - avoid slow emulated read if Mov */ 2635 rc = read_emulated(ctxt, ops, (unsigned long)c->dst.ptr, 2636 &c->dst.val, c->dst.bytes); 2637 if (rc != X86EMUL_CONTINUE) 2638 goto done; 2639 } 2640 c->dst.orig_val = c->dst.val; 2641 2642 special_insn: 2643 2644 if (c->twobyte) 2645 goto twobyte_insn; 2646 2647 switch (c->b) { 2648 case 0x00 ... 0x05: 2649 add: /* add */ 2650 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags); 2651 break; 2652 case 0x06: /* push es */ 2653 emulate_push_sreg(ctxt, ops, VCPU_SREG_ES); 2654 break; 2655 case 0x07: /* pop es */ 2656 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_ES); 2657 if (rc != X86EMUL_CONTINUE) 2658 goto done; 2659 break; 2660 case 0x08 ... 0x0d: 2661 or: /* or */ 2662 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags); 2663 break; 2664 case 0x0e: /* push cs */ 2665 emulate_push_sreg(ctxt, ops, VCPU_SREG_CS); 2666 break; 2667 case 0x10 ... 0x15: 2668 adc: /* adc */ 2669 emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags); 2670 break; 2671 case 0x16: /* push ss */ 2672 emulate_push_sreg(ctxt, ops, VCPU_SREG_SS); 2673 break; 2674 case 0x17: /* pop ss */ 2675 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_SS); 2676 if (rc != X86EMUL_CONTINUE) 2677 goto done; 2678 break; 2679 case 0x18 ... 0x1d: 2680 sbb: /* sbb */ 2681 emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags); 2682 break; 2683 case 0x1e: /* push ds */ 2684 emulate_push_sreg(ctxt, ops, VCPU_SREG_DS); 2685 break; 2686 case 0x1f: /* pop ds */ 2687 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_DS); 2688 if (rc != X86EMUL_CONTINUE) 2689 goto done; 2690 break; 2691 case 0x20 ... 0x25: 2692 and: /* and */ 2693 emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags); 2694 break; 2695 case 0x28 ... 0x2d: 2696 sub: /* sub */ 2697 emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags); 2698 break; 2699 case 0x30 ... 0x35: 2700 xor: /* xor */ 2701 emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags); 2702 break; 2703 case 0x38 ... 0x3d: 2704 cmp: /* cmp */ 2705 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); 2706 break; 2707 case 0x40 ... 0x47: /* inc r16/r32 */ 2708 emulate_1op("inc", c->dst, ctxt->eflags); 2709 break; 2710 case 0x48 ... 0x4f: /* dec r16/r32 */ 2711 emulate_1op("dec", c->dst, ctxt->eflags); 2712 break; 2713 case 0x50 ... 0x57: /* push reg */ 2714 emulate_push(ctxt, ops); 2715 break; 2716 case 0x58 ... 0x5f: /* pop reg */ 2717 pop_instruction: 2718 rc = emulate_pop(ctxt, ops, &c->dst.val, c->op_bytes); 2719 if (rc != X86EMUL_CONTINUE) 2720 goto done; 2721 break; 2722 case 0x60: /* pusha */ 2723 rc = emulate_pusha(ctxt, ops); 2724 if (rc != X86EMUL_CONTINUE) 2725 goto done; 2726 break; 2727 case 0x61: /* popa */ 2728 rc = emulate_popa(ctxt, ops); 2729 if (rc != X86EMUL_CONTINUE) 2730 goto done; 2731 break; 2732 case 0x63: /* movsxd */ 2733 if (ctxt->mode != X86EMUL_MODE_PROT64) 2734 goto cannot_emulate; 2735 c->dst.val = (s32) c->src.val; 2736 break; 2737 case 0x68: /* push imm */ 2738 case 0x6a: /* push imm8 */ 2739 emulate_push(ctxt, ops); 2740 break; 2741 case 0x6c: /* insb */ 2742 case 0x6d: /* insw/insd */ 2743 c->dst.bytes = min(c->dst.bytes, 4u); 2744 if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX], 2745 c->dst.bytes)) { 2746 emulate_gp(ctxt, 0); 2747 goto done; 2748 } 2749 if (!pio_in_emulated(ctxt, ops, c->dst.bytes, 2750 c->regs[VCPU_REGS_RDX], &c->dst.val)) 2751 goto done; /* IO is needed, skip writeback */ 2752 break; 2753 case 0x6e: /* outsb */ 2754 case 0x6f: /* outsw/outsd */ 2755 c->src.bytes = min(c->src.bytes, 4u); 2756 if (!emulator_io_permited(ctxt, ops, c->regs[VCPU_REGS_RDX], 2757 c->src.bytes)) { 2758 emulate_gp(ctxt, 0); 2759 goto done; 2760 } 2761 ops->pio_out_emulated(c->src.bytes, c->regs[VCPU_REGS_RDX], 2762 &c->src.val, 1, ctxt->vcpu); 2763 2764 c->dst.type = OP_NONE; /* nothing to writeback */ 2765 break; 2766 case 0x70 ... 0x7f: /* jcc (short) */ 2767 if (test_cc(c->b, ctxt->eflags)) 2768 jmp_rel(c, c->src.val); 2769 break; 2770 case 0x80 ... 0x83: /* Grp1 */ 2771 switch (c->modrm_reg) { 2772 case 0: 2773 goto add; 2774 case 1: 2775 goto or; 2776 case 2: 2777 goto adc; 2778 case 3: 2779 goto sbb; 2780 case 4: 2781 goto and; 2782 case 5: 2783 goto sub; 2784 case 6: 2785 goto xor; 2786 case 7: 2787 goto cmp; 2788 } 2789 break; 2790 case 0x84 ... 0x85: 2791 test: 2792 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); 2793 break; 2794 case 0x86 ... 0x87: /* xchg */ 2795 xchg: 2796 /* Write back the register source. */ 2797 switch (c->dst.bytes) { 2798 case 1: 2799 *(u8 *) c->src.ptr = (u8) c->dst.val; 2800 break; 2801 case 2: 2802 *(u16 *) c->src.ptr = (u16) c->dst.val; 2803 break; 2804 case 4: 2805 *c->src.ptr = (u32) c->dst.val; 2806 break; /* 64b reg: zero-extend */ 2807 case 8: 2808 *c->src.ptr = c->dst.val; 2809 break; 2810 } 2811 /* 2812 * Write back the memory destination with implicit LOCK 2813 * prefix. 2814 */ 2815 c->dst.val = c->src.val; 2816 c->lock_prefix = 1; 2817 break; 2818 case 0x88 ... 0x8b: /* mov */ 2819 goto mov; 2820 case 0x8c: /* mov r/m, sreg */ 2821 if (c->modrm_reg > VCPU_SREG_GS) { 2822 emulate_ud(ctxt); 2823 goto done; 2824 } 2825 c->dst.val = ops->get_segment_selector(c->modrm_reg, ctxt->vcpu); 2826 break; 2827 case 0x8d: /* lea r16/r32, m */ 2828 c->dst.val = c->modrm_ea; 2829 break; 2830 case 0x8e: { /* mov seg, r/m16 */ 2831 uint16_t sel; 2832 2833 sel = c->src.val; 2834 2835 if (c->modrm_reg == VCPU_SREG_CS || 2836 c->modrm_reg > VCPU_SREG_GS) { 2837 emulate_ud(ctxt); 2838 goto done; 2839 } 2840 2841 if (c->modrm_reg == VCPU_SREG_SS) 2842 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; 2843 2844 rc = load_segment_descriptor(ctxt, ops, sel, c->modrm_reg); 2845 2846 c->dst.type = OP_NONE; /* Disable writeback. */ 2847 break; 2848 } 2849 case 0x8f: /* pop (sole member of Grp1a) */ 2850 rc = emulate_grp1a(ctxt, ops); 2851 if (rc != X86EMUL_CONTINUE) 2852 goto done; 2853 break; 2854 case 0x90: /* nop / xchg r8,rax */ 2855 if (c->dst.ptr == (unsigned long *)&c->regs[VCPU_REGS_RAX]) { 2856 c->dst.type = OP_NONE; /* nop */ 2857 break; 2858 } 2859 case 0x91 ... 0x97: /* xchg reg,rax */ 2860 c->src.type = OP_REG; 2861 c->src.bytes = c->op_bytes; 2862 c->src.ptr = (unsigned long *) &c->regs[VCPU_REGS_RAX]; 2863 c->src.val = *(c->src.ptr); 2864 goto xchg; 2865 case 0x9c: /* pushf */ 2866 c->src.val = (unsigned long) ctxt->eflags; 2867 emulate_push(ctxt, ops); 2868 break; 2869 case 0x9d: /* popf */ 2870 c->dst.type = OP_REG; 2871 c->dst.ptr = (unsigned long *) &ctxt->eflags; 2872 c->dst.bytes = c->op_bytes; 2873 rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes); 2874 if (rc != X86EMUL_CONTINUE) 2875 goto done; 2876 break; 2877 case 0xa0 ... 0xa3: /* mov */ 2878 case 0xa4 ... 0xa5: /* movs */ 2879 goto mov; 2880 case 0xa6 ... 0xa7: /* cmps */ 2881 c->dst.type = OP_NONE; /* Disable writeback. */ 2882 DPRINTF("cmps: mem1=0x%p mem2=0x%p\n", c->src.ptr, c->dst.ptr); 2883 goto cmp; 2884 case 0xa8 ... 0xa9: /* test ax, imm */ 2885 goto test; 2886 case 0xaa ... 0xab: /* stos */ 2887 c->dst.val = c->regs[VCPU_REGS_RAX]; 2888 break; 2889 case 0xac ... 0xad: /* lods */ 2890 goto mov; 2891 case 0xae ... 0xaf: /* scas */ 2892 DPRINTF("Urk! I don't handle SCAS.\n"); 2893 goto cannot_emulate; 2894 case 0xb0 ... 0xbf: /* mov r, imm */ 2895 goto mov; 2896 case 0xc0 ... 0xc1: 2897 emulate_grp2(ctxt); 2898 break; 2899 case 0xc3: /* ret */ 2900 c->dst.type = OP_REG; 2901 c->dst.ptr = &c->eip; 2902 c->dst.bytes = c->op_bytes; 2903 goto pop_instruction; 2904 case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */ 2905 mov: 2906 c->dst.val = c->src.val; 2907 break; 2908 case 0xcb: /* ret far */ 2909 rc = emulate_ret_far(ctxt, ops); 2910 if (rc != X86EMUL_CONTINUE) 2911 goto done; 2912 break; 2913 case 0xd0 ... 0xd1: /* Grp2 */ 2914 c->src.val = 1; 2915 emulate_grp2(ctxt); 2916 break; 2917 case 0xd2 ... 0xd3: /* Grp2 */ 2918 c->src.val = c->regs[VCPU_REGS_RCX]; 2919 emulate_grp2(ctxt); 2920 break; 2921 case 0xe4: /* inb */ 2922 case 0xe5: /* in */ 2923 goto do_io_in; 2924 case 0xe6: /* outb */ 2925 case 0xe7: /* out */ 2926 goto do_io_out; 2927 case 0xe8: /* call (near) */ { 2928 long int rel = c->src.val; 2929 c->src.val = (unsigned long) c->eip; 2930 jmp_rel(c, rel); 2931 emulate_push(ctxt, ops); 2932 break; 2933 } 2934 case 0xe9: /* jmp rel */ 2935 goto jmp; 2936 case 0xea: { /* jmp far */ 2937 unsigned short sel; 2938 jump_far: 2939 memcpy(&sel, c->src.valptr + c->op_bytes, 2); 2940 2941 if (load_segment_descriptor(ctxt, ops, sel, VCPU_SREG_CS)) 2942 goto done; 2943 2944 c->eip = 0; 2945 memcpy(&c->eip, c->src.valptr, c->op_bytes); 2946 break; 2947 } 2948 case 0xeb: 2949 jmp: /* jmp rel short */ 2950 jmp_rel(c, c->src.val); 2951 c->dst.type = OP_NONE; /* Disable writeback. */ 2952 break; 2953 case 0xec: /* in al,dx */ 2954 case 0xed: /* in (e/r)ax,dx */ 2955 c->src.val = c->regs[VCPU_REGS_RDX]; 2956 do_io_in: 2957 c->dst.bytes = min(c->dst.bytes, 4u); 2958 if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) { 2959 emulate_gp(ctxt, 0); 2960 goto done; 2961 } 2962 if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val, 2963 &c->dst.val)) 2964 goto done; /* IO is needed */ 2965 break; 2966 case 0xee: /* out dx,al */ 2967 case 0xef: /* out dx,(e/r)ax */ 2968 c->src.val = c->regs[VCPU_REGS_RDX]; 2969 do_io_out: 2970 c->dst.bytes = min(c->dst.bytes, 4u); 2971 if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) { 2972 emulate_gp(ctxt, 0); 2973 goto done; 2974 } 2975 ops->pio_out_emulated(c->dst.bytes, c->src.val, &c->dst.val, 1, 2976 ctxt->vcpu); 2977 c->dst.type = OP_NONE; /* Disable writeback. */ 2978 break; 2979 case 0xf4: /* hlt */ 2980 ctxt->vcpu->arch.halt_request = 1; 2981 break; 2982 case 0xf5: /* cmc */ 2983 /* complement carry flag from eflags reg */ 2984 ctxt->eflags ^= EFLG_CF; 2985 c->dst.type = OP_NONE; /* Disable writeback. */ 2986 break; 2987 case 0xf6 ... 0xf7: /* Grp3 */ 2988 if (!emulate_grp3(ctxt, ops)) 2989 goto cannot_emulate; 2990 break; 2991 case 0xf8: /* clc */ 2992 ctxt->eflags &= ~EFLG_CF; 2993 c->dst.type = OP_NONE; /* Disable writeback. */ 2994 break; 2995 case 0xfa: /* cli */ 2996 if (emulator_bad_iopl(ctxt, ops)) { 2997 emulate_gp(ctxt, 0); 2998 goto done; 2999 } else { 3000 ctxt->eflags &= ~X86_EFLAGS_IF; 3001 c->dst.type = OP_NONE; /* Disable writeback. */ 3002 } 3003 break; 3004 case 0xfb: /* sti */ 3005 if (emulator_bad_iopl(ctxt, ops)) { 3006 emulate_gp(ctxt, 0); 3007 goto done; 3008 } else { 3009 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; 3010 ctxt->eflags |= X86_EFLAGS_IF; 3011 c->dst.type = OP_NONE; /* Disable writeback. */ 3012 } 3013 break; 3014 case 0xfc: /* cld */ 3015 ctxt->eflags &= ~EFLG_DF; 3016 c->dst.type = OP_NONE; /* Disable writeback. */ 3017 break; 3018 case 0xfd: /* std */ 3019 ctxt->eflags |= EFLG_DF; 3020 c->dst.type = OP_NONE; /* Disable writeback. */ 3021 break; 3022 case 0xfe: /* Grp4 */ 3023 grp45: 3024 rc = emulate_grp45(ctxt, ops); 3025 if (rc != X86EMUL_CONTINUE) 3026 goto done; 3027 break; 3028 case 0xff: /* Grp5 */ 3029 if (c->modrm_reg == 5) 3030 goto jump_far; 3031 goto grp45; 3032 } 3033 3034 writeback: 3035 rc = writeback(ctxt, ops); 3036 if (rc != X86EMUL_CONTINUE) 3037 goto done; 3038 3039 /* 3040 * restore dst type in case the decoding will be reused 3041 * (happens for string instruction ) 3042 */ 3043 c->dst.type = saved_dst_type; 3044 3045 if ((c->d & SrcMask) == SrcSI) 3046 string_addr_inc(ctxt, seg_override_base(ctxt, ops, c), 3047 VCPU_REGS_RSI, &c->src); 3048 3049 if ((c->d & DstMask) == DstDI) 3050 string_addr_inc(ctxt, es_base(ctxt, ops), VCPU_REGS_RDI, 3051 &c->dst); 3052 3053 if (c->rep_prefix && (c->d & String)) { 3054 struct read_cache *rc = &ctxt->decode.io_read; 3055 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); 3056 /* 3057 * Re-enter guest when pio read ahead buffer is empty or, 3058 * if it is not used, after each 1024 iteration. 3059 */ 3060 if ((rc->end == 0 && !(c->regs[VCPU_REGS_RCX] & 0x3ff)) || 3061 (rc->end != 0 && rc->end == rc->pos)) 3062 ctxt->restart = false; 3063 } 3064 /* 3065 * reset read cache here in case string instruction is restared 3066 * without decoding 3067 */ 3068 ctxt->decode.mem_read.end = 0; 3069 ctxt->eip = c->eip; 3070 3071 done: 3072 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0; 3073 3074 twobyte_insn: 3075 switch (c->b) { 3076 case 0x01: /* lgdt, lidt, lmsw */ 3077 switch (c->modrm_reg) { 3078 u16 size; 3079 unsigned long address; 3080 3081 case 0: /* vmcall */ 3082 if (c->modrm_mod != 3 || c->modrm_rm != 1) 3083 goto cannot_emulate; 3084 3085 rc = kvm_fix_hypercall(ctxt->vcpu); 3086 if (rc != X86EMUL_CONTINUE) 3087 goto done; 3088 3089 /* Let the processor re-execute the fixed hypercall */ 3090 c->eip = ctxt->eip; 3091 /* Disable writeback. */ 3092 c->dst.type = OP_NONE; 3093 break; 3094 case 2: /* lgdt */ 3095 rc = read_descriptor(ctxt, ops, c->src.ptr, 3096 &size, &address, c->op_bytes); 3097 if (rc != X86EMUL_CONTINUE) 3098 goto done; 3099 realmode_lgdt(ctxt->vcpu, size, address); 3100 /* Disable writeback. */ 3101 c->dst.type = OP_NONE; 3102 break; 3103 case 3: /* lidt/vmmcall */ 3104 if (c->modrm_mod == 3) { 3105 switch (c->modrm_rm) { 3106 case 1: 3107 rc = kvm_fix_hypercall(ctxt->vcpu); 3108 if (rc != X86EMUL_CONTINUE) 3109 goto done; 3110 break; 3111 default: 3112 goto cannot_emulate; 3113 } 3114 } else { 3115 rc = read_descriptor(ctxt, ops, c->src.ptr, 3116 &size, &address, 3117 c->op_bytes); 3118 if (rc != X86EMUL_CONTINUE) 3119 goto done; 3120 realmode_lidt(ctxt->vcpu, size, address); 3121 } 3122 /* Disable writeback. */ 3123 c->dst.type = OP_NONE; 3124 break; 3125 case 4: /* smsw */ 3126 c->dst.bytes = 2; 3127 c->dst.val = ops->get_cr(0, ctxt->vcpu); 3128 break; 3129 case 6: /* lmsw */ 3130 ops->set_cr(0, (ops->get_cr(0, ctxt->vcpu) & ~0x0ful) | 3131 (c->src.val & 0x0f), ctxt->vcpu); 3132 c->dst.type = OP_NONE; 3133 break; 3134 case 5: /* not defined */ 3135 emulate_ud(ctxt); 3136 goto done; 3137 case 7: /* invlpg*/ 3138 emulate_invlpg(ctxt->vcpu, c->modrm_ea); 3139 /* Disable writeback. */ 3140 c->dst.type = OP_NONE; 3141 break; 3142 default: 3143 goto cannot_emulate; 3144 } 3145 break; 3146 case 0x05: /* syscall */ 3147 rc = emulate_syscall(ctxt, ops); 3148 if (rc != X86EMUL_CONTINUE) 3149 goto done; 3150 else 3151 goto writeback; 3152 break; 3153 case 0x06: 3154 emulate_clts(ctxt->vcpu); 3155 c->dst.type = OP_NONE; 3156 break; 3157 case 0x09: /* wbinvd */ 3158 kvm_emulate_wbinvd(ctxt->vcpu); 3159 c->dst.type = OP_NONE; 3160 break; 3161 case 0x08: /* invd */ 3162 case 0x0d: /* GrpP (prefetch) */ 3163 case 0x18: /* Grp16 (prefetch/nop) */ 3164 c->dst.type = OP_NONE; 3165 break; 3166 case 0x20: /* mov cr, reg */ 3167 switch (c->modrm_reg) { 3168 case 1: 3169 case 5 ... 7: 3170 case 9 ... 15: 3171 emulate_ud(ctxt); 3172 goto done; 3173 } 3174 c->regs[c->modrm_rm] = ops->get_cr(c->modrm_reg, ctxt->vcpu); 3175 c->dst.type = OP_NONE; /* no writeback */ 3176 break; 3177 case 0x21: /* mov from dr to reg */ 3178 if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && 3179 (c->modrm_reg == 4 || c->modrm_reg == 5)) { 3180 emulate_ud(ctxt); 3181 goto done; 3182 } 3183 ops->get_dr(c->modrm_reg, &c->regs[c->modrm_rm], ctxt->vcpu); 3184 c->dst.type = OP_NONE; /* no writeback */ 3185 break; 3186 case 0x22: /* mov reg, cr */ 3187 if (ops->set_cr(c->modrm_reg, c->modrm_val, ctxt->vcpu)) { 3188 emulate_gp(ctxt, 0); 3189 goto done; 3190 } 3191 c->dst.type = OP_NONE; 3192 break; 3193 case 0x23: /* mov from reg to dr */ 3194 if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) && 3195 (c->modrm_reg == 4 || c->modrm_reg == 5)) { 3196 emulate_ud(ctxt); 3197 goto done; 3198 } 3199 3200 if (ops->set_dr(c->modrm_reg, c->regs[c->modrm_rm] & 3201 ((ctxt->mode == X86EMUL_MODE_PROT64) ? 3202 ~0ULL : ~0U), ctxt->vcpu) < 0) { 3203 /* #UD condition is already handled by the code above */ 3204 emulate_gp(ctxt, 0); 3205 goto done; 3206 } 3207 3208 c->dst.type = OP_NONE; /* no writeback */ 3209 break; 3210 case 0x30: 3211 /* wrmsr */ 3212 msr_data = (u32)c->regs[VCPU_REGS_RAX] 3213 | ((u64)c->regs[VCPU_REGS_RDX] << 32); 3214 if (ops->set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data)) { 3215 emulate_gp(ctxt, 0); 3216 goto done; 3217 } 3218 rc = X86EMUL_CONTINUE; 3219 c->dst.type = OP_NONE; 3220 break; 3221 case 0x32: 3222 /* rdmsr */ 3223 if (ops->get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data)) { 3224 emulate_gp(ctxt, 0); 3225 goto done; 3226 } else { 3227 c->regs[VCPU_REGS_RAX] = (u32)msr_data; 3228 c->regs[VCPU_REGS_RDX] = msr_data >> 32; 3229 } 3230 rc = X86EMUL_CONTINUE; 3231 c->dst.type = OP_NONE; 3232 break; 3233 case 0x34: /* sysenter */ 3234 rc = emulate_sysenter(ctxt, ops); 3235 if (rc != X86EMUL_CONTINUE) 3236 goto done; 3237 else 3238 goto writeback; 3239 break; 3240 case 0x35: /* sysexit */ 3241 rc = emulate_sysexit(ctxt, ops); 3242 if (rc != X86EMUL_CONTINUE) 3243 goto done; 3244 else 3245 goto writeback; 3246 break; 3247 case 0x40 ... 0x4f: /* cmov */ 3248 c->dst.val = c->dst.orig_val = c->src.val; 3249 if (!test_cc(c->b, ctxt->eflags)) 3250 c->dst.type = OP_NONE; /* no writeback */ 3251 break; 3252 case 0x80 ... 0x8f: /* jnz rel, etc*/ 3253 if (test_cc(c->b, ctxt->eflags)) 3254 jmp_rel(c, c->src.val); 3255 c->dst.type = OP_NONE; 3256 break; 3257 case 0xa0: /* push fs */ 3258 emulate_push_sreg(ctxt, ops, VCPU_SREG_FS); 3259 break; 3260 case 0xa1: /* pop fs */ 3261 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_FS); 3262 if (rc != X86EMUL_CONTINUE) 3263 goto done; 3264 break; 3265 case 0xa3: 3266 bt: /* bt */ 3267 c->dst.type = OP_NONE; 3268 /* only subword offset */ 3269 c->src.val &= (c->dst.bytes << 3) - 1; 3270 emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags); 3271 break; 3272 case 0xa4: /* shld imm8, r, r/m */ 3273 case 0xa5: /* shld cl, r, r/m */ 3274 emulate_2op_cl("shld", c->src2, c->src, c->dst, ctxt->eflags); 3275 break; 3276 case 0xa8: /* push gs */ 3277 emulate_push_sreg(ctxt, ops, VCPU_SREG_GS); 3278 break; 3279 case 0xa9: /* pop gs */ 3280 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_GS); 3281 if (rc != X86EMUL_CONTINUE) 3282 goto done; 3283 break; 3284 case 0xab: 3285 bts: /* bts */ 3286 /* only subword offset */ 3287 c->src.val &= (c->dst.bytes << 3) - 1; 3288 emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags); 3289 break; 3290 case 0xac: /* shrd imm8, r, r/m */ 3291 case 0xad: /* shrd cl, r, r/m */ 3292 emulate_2op_cl("shrd", c->src2, c->src, c->dst, ctxt->eflags); 3293 break; 3294 case 0xae: /* clflush */ 3295 break; 3296 case 0xb0 ... 0xb1: /* cmpxchg */ 3297 /* 3298 * Save real source value, then compare EAX against 3299 * destination. 3300 */ 3301 c->src.orig_val = c->src.val; 3302 c->src.val = c->regs[VCPU_REGS_RAX]; 3303 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); 3304 if (ctxt->eflags & EFLG_ZF) { 3305 /* Success: write back to memory. */ 3306 c->dst.val = c->src.orig_val; 3307 } else { 3308 /* Failure: write the value we saw to EAX. */ 3309 c->dst.type = OP_REG; 3310 c->dst.ptr = (unsigned long *)&c->regs[VCPU_REGS_RAX]; 3311 } 3312 break; 3313 case 0xb3: 3314 btr: /* btr */ 3315 /* only subword offset */ 3316 c->src.val &= (c->dst.bytes << 3) - 1; 3317 emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags); 3318 break; 3319 case 0xb6 ... 0xb7: /* movzx */ 3320 c->dst.bytes = c->op_bytes; 3321 c->dst.val = (c->d & ByteOp) ? (u8) c->src.val 3322 : (u16) c->src.val; 3323 break; 3324 case 0xba: /* Grp8 */ 3325 switch (c->modrm_reg & 3) { 3326 case 0: 3327 goto bt; 3328 case 1: 3329 goto bts; 3330 case 2: 3331 goto btr; 3332 case 3: 3333 goto btc; 3334 } 3335 break; 3336 case 0xbb: 3337 btc: /* btc */ 3338 /* only subword offset */ 3339 c->src.val &= (c->dst.bytes << 3) - 1; 3340 emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags); 3341 break; 3342 case 0xbe ... 0xbf: /* movsx */ 3343 c->dst.bytes = c->op_bytes; 3344 c->dst.val = (c->d & ByteOp) ? (s8) c->src.val : 3345 (s16) c->src.val; 3346 break; 3347 case 0xc3: /* movnti */ 3348 c->dst.bytes = c->op_bytes; 3349 c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val : 3350 (u64) c->src.val; 3351 break; 3352 case 0xc7: /* Grp9 (cmpxchg8b) */ 3353 rc = emulate_grp9(ctxt, ops); 3354 if (rc != X86EMUL_CONTINUE) 3355 goto done; 3356 break; 3357 } 3358 goto writeback; 3359 3360 cannot_emulate: 3361 DPRINTF("Cannot emulate %02x\n", c->b); 3362 return -1; 3363 } 3364