1 // SPDX-License-Identifier: GPL-2.0-only 2 /****************************************************************************** 3 * emulate.c 4 * 5 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. 6 * 7 * Copyright (c) 2005 Keir Fraser 8 * 9 * Linux coding style, mod r/m decoder, segment base fixes, real-mode 10 * privileged instructions: 11 * 12 * Copyright (C) 2006 Qumranet 13 * Copyright 2010 Red Hat, Inc. and/or its affiliates. 14 * 15 * Avi Kivity <avi@qumranet.com> 16 * Yaniv Kamay <yaniv@qumranet.com> 17 * 18 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 19 */ 20 21 #include <linux/kvm_host.h> 22 #include "kvm_cache_regs.h" 23 #include "kvm_emulate.h" 24 #include <linux/stringify.h> 25 #include <asm/debugreg.h> 26 #include <asm/nospec-branch.h> 27 #include <asm/ibt.h> 28 29 #include "x86.h" 30 #include "tss.h" 31 #include "mmu.h" 32 #include "pmu.h" 33 34 /* 35 * Operand types 36 */ 37 #define OpNone 0ull 38 #define OpImplicit 1ull /* No generic decode */ 39 #define OpReg 2ull /* Register */ 40 #define OpMem 3ull /* Memory */ 41 #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */ 42 #define OpDI 5ull /* ES:DI/EDI/RDI */ 43 #define OpMem64 6ull /* Memory, 64-bit */ 44 #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */ 45 #define OpDX 8ull /* DX register */ 46 #define OpCL 9ull /* CL register (for shifts) */ 47 #define OpImmByte 10ull /* 8-bit sign extended immediate */ 48 #define OpOne 11ull /* Implied 1 */ 49 #define OpImm 12ull /* Sign extended up to 32-bit immediate */ 50 #define OpMem16 13ull /* Memory operand (16-bit). */ 51 #define OpMem32 14ull /* Memory operand (32-bit). */ 52 #define OpImmU 15ull /* Immediate operand, zero extended */ 53 #define OpSI 16ull /* SI/ESI/RSI */ 54 #define OpImmFAddr 17ull /* Immediate far address */ 55 #define OpMemFAddr 18ull /* Far address in memory */ 56 #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */ 57 #define OpES 20ull /* ES */ 58 #define OpCS 21ull /* CS */ 59 #define OpSS 22ull /* SS */ 60 #define OpDS 23ull /* DS */ 61 #define OpFS 24ull /* FS */ 62 #define OpGS 25ull /* GS */ 63 #define OpMem8 26ull /* 8-bit zero extended memory operand */ 64 #define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */ 65 #define OpXLat 28ull /* memory at BX/EBX/RBX + zero-extended AL */ 66 #define OpAccLo 29ull /* Low part of extended acc (AX/AX/EAX/RAX) */ 67 #define OpAccHi 30ull /* High part of extended acc (-/DX/EDX/RDX) */ 68 69 #define OpBits 5 /* Width of operand field */ 70 #define OpMask ((1ull << OpBits) - 1) 71 72 /* 73 * Opcode effective-address decode tables. 74 * Note that we only emulate instructions that have at least one memory 75 * operand (excluding implicit stack references). We assume that stack 76 * references and instruction fetches will never occur in special memory 77 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need 78 * not be handled. 79 */ 80 81 /* Operand sizes: 8-bit operands or specified/overridden size. */ 82 #define ByteOp (1<<0) /* 8-bit operands. */ 83 /* Destination operand type. */ 84 #define DstShift 1 85 #define ImplicitOps (OpImplicit << DstShift) 86 #define DstReg (OpReg << DstShift) 87 #define DstMem (OpMem << DstShift) 88 #define DstAcc (OpAcc << DstShift) 89 #define DstDI (OpDI << DstShift) 90 #define DstMem64 (OpMem64 << DstShift) 91 #define DstMem16 (OpMem16 << DstShift) 92 #define DstImmUByte (OpImmUByte << DstShift) 93 #define DstDX (OpDX << DstShift) 94 #define DstAccLo (OpAccLo << DstShift) 95 #define DstMask (OpMask << DstShift) 96 /* Source operand type. */ 97 #define SrcShift 6 98 #define SrcNone (OpNone << SrcShift) 99 #define SrcReg (OpReg << SrcShift) 100 #define SrcMem (OpMem << SrcShift) 101 #define SrcMem16 (OpMem16 << SrcShift) 102 #define SrcMem32 (OpMem32 << SrcShift) 103 #define SrcImm (OpImm << SrcShift) 104 #define SrcImmByte (OpImmByte << SrcShift) 105 #define SrcOne (OpOne << SrcShift) 106 #define SrcImmUByte (OpImmUByte << SrcShift) 107 #define SrcImmU (OpImmU << SrcShift) 108 #define SrcSI (OpSI << SrcShift) 109 #define SrcXLat (OpXLat << SrcShift) 110 #define SrcImmFAddr (OpImmFAddr << SrcShift) 111 #define SrcMemFAddr (OpMemFAddr << SrcShift) 112 #define SrcAcc (OpAcc << SrcShift) 113 #define SrcImmU16 (OpImmU16 << SrcShift) 114 #define SrcImm64 (OpImm64 << SrcShift) 115 #define SrcDX (OpDX << SrcShift) 116 #define SrcMem8 (OpMem8 << SrcShift) 117 #define SrcAccHi (OpAccHi << SrcShift) 118 #define SrcMask (OpMask << SrcShift) 119 #define BitOp (1<<11) 120 #define MemAbs (1<<12) /* Memory operand is absolute displacement */ 121 #define String (1<<13) /* String instruction (rep capable) */ 122 #define Stack (1<<14) /* Stack instruction (push/pop) */ 123 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */ 124 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */ 125 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */ 126 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */ 127 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */ 128 #define Escape (5<<15) /* Escape to coprocessor instruction */ 129 #define InstrDual (6<<15) /* Alternate instruction decoding of mod == 3 */ 130 #define ModeDual (7<<15) /* Different instruction for 32/64 bit */ 131 #define Sse (1<<18) /* SSE Vector instruction */ 132 /* Generic ModRM decode. */ 133 #define ModRM (1<<19) 134 /* Destination is only written; never read. */ 135 #define Mov (1<<20) 136 /* Misc flags */ 137 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */ 138 #define EmulateOnUD (1<<22) /* Emulate if unsupported by the host */ 139 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */ 140 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */ 141 #define Undefined (1<<25) /* No Such Instruction */ 142 #define Lock (1<<26) /* lock prefix is allowed for the instruction */ 143 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ 144 #define No64 (1<<28) 145 #define PageTable (1 << 29) /* instruction used to write page table */ 146 #define NotImpl (1 << 30) /* instruction is not implemented */ 147 /* Source 2 operand type */ 148 #define Src2Shift (31) 149 #define Src2None (OpNone << Src2Shift) 150 #define Src2Mem (OpMem << Src2Shift) 151 #define Src2CL (OpCL << Src2Shift) 152 #define Src2ImmByte (OpImmByte << Src2Shift) 153 #define Src2One (OpOne << Src2Shift) 154 #define Src2Imm (OpImm << Src2Shift) 155 #define Src2ES (OpES << Src2Shift) 156 #define Src2CS (OpCS << Src2Shift) 157 #define Src2SS (OpSS << Src2Shift) 158 #define Src2DS (OpDS << Src2Shift) 159 #define Src2FS (OpFS << Src2Shift) 160 #define Src2GS (OpGS << Src2Shift) 161 #define Src2Mask (OpMask << Src2Shift) 162 #define Mmx ((u64)1 << 40) /* MMX Vector instruction */ 163 #define AlignMask ((u64)7 << 41) 164 #define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */ 165 #define Unaligned ((u64)2 << 41) /* Explicitly unaligned (e.g. MOVDQU) */ 166 #define Avx ((u64)3 << 41) /* Advanced Vector Extensions */ 167 #define Aligned16 ((u64)4 << 41) /* Aligned to 16 byte boundary (e.g. FXSAVE) */ 168 #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ 169 #define NoWrite ((u64)1 << 45) /* No writeback */ 170 #define SrcWrite ((u64)1 << 46) /* Write back src operand */ 171 #define NoMod ((u64)1 << 47) /* Mod field is ignored */ 172 #define Intercept ((u64)1 << 48) /* Has valid intercept field */ 173 #define CheckPerm ((u64)1 << 49) /* Has valid check_perm field */ 174 #define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */ 175 #define NearBranch ((u64)1 << 52) /* Near branches */ 176 #define No16 ((u64)1 << 53) /* No 16 bit operand */ 177 #define IncSP ((u64)1 << 54) /* SP is incremented before ModRM calc */ 178 #define TwoMemOp ((u64)1 << 55) /* Instruction has two memory operand */ 179 #define IsBranch ((u64)1 << 56) /* Instruction is considered a branch. */ 180 181 #define DstXacc (DstAccLo | SrcAccHi | SrcWrite) 182 183 #define X2(x...) x, x 184 #define X3(x...) X2(x), x 185 #define X4(x...) X2(x), X2(x) 186 #define X5(x...) X4(x), x 187 #define X6(x...) X4(x), X2(x) 188 #define X7(x...) X4(x), X3(x) 189 #define X8(x...) X4(x), X4(x) 190 #define X16(x...) X8(x), X8(x) 191 192 struct opcode { 193 u64 flags; 194 u8 intercept; 195 u8 pad[7]; 196 union { 197 int (*execute)(struct x86_emulate_ctxt *ctxt); 198 const struct opcode *group; 199 const struct group_dual *gdual; 200 const struct gprefix *gprefix; 201 const struct escape *esc; 202 const struct instr_dual *idual; 203 const struct mode_dual *mdual; 204 void (*fastop)(struct fastop *fake); 205 } u; 206 int (*check_perm)(struct x86_emulate_ctxt *ctxt); 207 }; 208 209 struct group_dual { 210 struct opcode mod012[8]; 211 struct opcode mod3[8]; 212 }; 213 214 struct gprefix { 215 struct opcode pfx_no; 216 struct opcode pfx_66; 217 struct opcode pfx_f2; 218 struct opcode pfx_f3; 219 }; 220 221 struct escape { 222 struct opcode op[8]; 223 struct opcode high[64]; 224 }; 225 226 struct instr_dual { 227 struct opcode mod012; 228 struct opcode mod3; 229 }; 230 231 struct mode_dual { 232 struct opcode mode32; 233 struct opcode mode64; 234 }; 235 236 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a 237 238 enum x86_transfer_type { 239 X86_TRANSFER_NONE, 240 X86_TRANSFER_CALL_JMP, 241 X86_TRANSFER_RET, 242 X86_TRANSFER_TASK_SWITCH, 243 }; 244 245 static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr) 246 { 247 if (KVM_EMULATOR_BUG_ON(nr >= NR_EMULATOR_GPRS, ctxt)) 248 nr &= NR_EMULATOR_GPRS - 1; 249 250 if (!(ctxt->regs_valid & (1 << nr))) { 251 ctxt->regs_valid |= 1 << nr; 252 ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr); 253 } 254 return ctxt->_regs[nr]; 255 } 256 257 static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr) 258 { 259 if (KVM_EMULATOR_BUG_ON(nr >= NR_EMULATOR_GPRS, ctxt)) 260 nr &= NR_EMULATOR_GPRS - 1; 261 262 BUILD_BUG_ON(sizeof(ctxt->regs_dirty) * BITS_PER_BYTE < NR_EMULATOR_GPRS); 263 BUILD_BUG_ON(sizeof(ctxt->regs_valid) * BITS_PER_BYTE < NR_EMULATOR_GPRS); 264 265 ctxt->regs_valid |= 1 << nr; 266 ctxt->regs_dirty |= 1 << nr; 267 return &ctxt->_regs[nr]; 268 } 269 270 static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr) 271 { 272 reg_read(ctxt, nr); 273 return reg_write(ctxt, nr); 274 } 275 276 static void writeback_registers(struct x86_emulate_ctxt *ctxt) 277 { 278 unsigned long dirty = ctxt->regs_dirty; 279 unsigned reg; 280 281 for_each_set_bit(reg, &dirty, NR_EMULATOR_GPRS) 282 ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]); 283 } 284 285 static void invalidate_registers(struct x86_emulate_ctxt *ctxt) 286 { 287 ctxt->regs_dirty = 0; 288 ctxt->regs_valid = 0; 289 } 290 291 /* 292 * These EFLAGS bits are restored from saved value during emulation, and 293 * any changes are written back to the saved value after emulation. 294 */ 295 #define EFLAGS_MASK (X86_EFLAGS_OF|X86_EFLAGS_SF|X86_EFLAGS_ZF|X86_EFLAGS_AF|\ 296 X86_EFLAGS_PF|X86_EFLAGS_CF) 297 298 #ifdef CONFIG_X86_64 299 #define ON64(x) x 300 #else 301 #define ON64(x) 302 #endif 303 304 /* 305 * fastop functions have a special calling convention: 306 * 307 * dst: rax (in/out) 308 * src: rdx (in/out) 309 * src2: rcx (in) 310 * flags: rflags (in/out) 311 * ex: rsi (in:fastop pointer, out:zero if exception) 312 * 313 * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for 314 * different operand sizes can be reached by calculation, rather than a jump 315 * table (which would be bigger than the code). 316 * 317 * The 16 byte alignment, considering 5 bytes for the RET thunk, 3 for ENDBR 318 * and 1 for the straight line speculation INT3, leaves 7 bytes for the 319 * body of the function. Currently none is larger than 4. 320 */ 321 static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop); 322 323 #define FASTOP_SIZE 16 324 325 #define __FOP_FUNC(name) \ 326 ".align " __stringify(FASTOP_SIZE) " \n\t" \ 327 ".type " name ", @function \n\t" \ 328 name ":\n\t" \ 329 ASM_ENDBR 330 331 #define FOP_FUNC(name) \ 332 __FOP_FUNC(#name) 333 334 #define __FOP_RET(name) \ 335 "11: " ASM_RET \ 336 ".size " name ", .-" name "\n\t" 337 338 #define FOP_RET(name) \ 339 __FOP_RET(#name) 340 341 #define __FOP_START(op, align) \ 342 extern void em_##op(struct fastop *fake); \ 343 asm(".pushsection .text, \"ax\" \n\t" \ 344 ".global em_" #op " \n\t" \ 345 ".align " __stringify(align) " \n\t" \ 346 "em_" #op ":\n\t" 347 348 #define FOP_START(op) __FOP_START(op, FASTOP_SIZE) 349 350 #define FOP_END \ 351 ".popsection") 352 353 #define __FOPNOP(name) \ 354 __FOP_FUNC(name) \ 355 __FOP_RET(name) 356 357 #define FOPNOP() \ 358 __FOPNOP(__stringify(__UNIQUE_ID(nop))) 359 360 #define FOP1E(op, dst) \ 361 __FOP_FUNC(#op "_" #dst) \ 362 "10: " #op " %" #dst " \n\t" \ 363 __FOP_RET(#op "_" #dst) 364 365 #define FOP1EEX(op, dst) \ 366 FOP1E(op, dst) _ASM_EXTABLE_TYPE_REG(10b, 11b, EX_TYPE_ZERO_REG, %%esi) 367 368 #define FASTOP1(op) \ 369 FOP_START(op) \ 370 FOP1E(op##b, al) \ 371 FOP1E(op##w, ax) \ 372 FOP1E(op##l, eax) \ 373 ON64(FOP1E(op##q, rax)) \ 374 FOP_END 375 376 /* 1-operand, using src2 (for MUL/DIV r/m) */ 377 #define FASTOP1SRC2(op, name) \ 378 FOP_START(name) \ 379 FOP1E(op, cl) \ 380 FOP1E(op, cx) \ 381 FOP1E(op, ecx) \ 382 ON64(FOP1E(op, rcx)) \ 383 FOP_END 384 385 /* 1-operand, using src2 (for MUL/DIV r/m), with exceptions */ 386 #define FASTOP1SRC2EX(op, name) \ 387 FOP_START(name) \ 388 FOP1EEX(op, cl) \ 389 FOP1EEX(op, cx) \ 390 FOP1EEX(op, ecx) \ 391 ON64(FOP1EEX(op, rcx)) \ 392 FOP_END 393 394 #define FOP2E(op, dst, src) \ 395 __FOP_FUNC(#op "_" #dst "_" #src) \ 396 #op " %" #src ", %" #dst " \n\t" \ 397 __FOP_RET(#op "_" #dst "_" #src) 398 399 #define FASTOP2(op) \ 400 FOP_START(op) \ 401 FOP2E(op##b, al, dl) \ 402 FOP2E(op##w, ax, dx) \ 403 FOP2E(op##l, eax, edx) \ 404 ON64(FOP2E(op##q, rax, rdx)) \ 405 FOP_END 406 407 /* 2 operand, word only */ 408 #define FASTOP2W(op) \ 409 FOP_START(op) \ 410 FOPNOP() \ 411 FOP2E(op##w, ax, dx) \ 412 FOP2E(op##l, eax, edx) \ 413 ON64(FOP2E(op##q, rax, rdx)) \ 414 FOP_END 415 416 /* 2 operand, src is CL */ 417 #define FASTOP2CL(op) \ 418 FOP_START(op) \ 419 FOP2E(op##b, al, cl) \ 420 FOP2E(op##w, ax, cl) \ 421 FOP2E(op##l, eax, cl) \ 422 ON64(FOP2E(op##q, rax, cl)) \ 423 FOP_END 424 425 /* 2 operand, src and dest are reversed */ 426 #define FASTOP2R(op, name) \ 427 FOP_START(name) \ 428 FOP2E(op##b, dl, al) \ 429 FOP2E(op##w, dx, ax) \ 430 FOP2E(op##l, edx, eax) \ 431 ON64(FOP2E(op##q, rdx, rax)) \ 432 FOP_END 433 434 #define FOP3E(op, dst, src, src2) \ 435 __FOP_FUNC(#op "_" #dst "_" #src "_" #src2) \ 436 #op " %" #src2 ", %" #src ", %" #dst " \n\t"\ 437 __FOP_RET(#op "_" #dst "_" #src "_" #src2) 438 439 /* 3-operand, word-only, src2=cl */ 440 #define FASTOP3WCL(op) \ 441 FOP_START(op) \ 442 FOPNOP() \ 443 FOP3E(op##w, ax, dx, cl) \ 444 FOP3E(op##l, eax, edx, cl) \ 445 ON64(FOP3E(op##q, rax, rdx, cl)) \ 446 FOP_END 447 448 /* Special case for SETcc - 1 instruction per cc */ 449 450 /* 451 * Depending on .config the SETcc functions look like: 452 * 453 * ENDBR [4 bytes; CONFIG_X86_KERNEL_IBT] 454 * SETcc %al [3 bytes] 455 * RET | JMP __x86_return_thunk [1,5 bytes; CONFIG_RETHUNK] 456 * INT3 [1 byte; CONFIG_SLS] 457 */ 458 #define SETCC_ALIGN 16 459 460 #define FOP_SETCC(op) \ 461 ".align " __stringify(SETCC_ALIGN) " \n\t" \ 462 ".type " #op ", @function \n\t" \ 463 #op ": \n\t" \ 464 ASM_ENDBR \ 465 #op " %al \n\t" \ 466 __FOP_RET(#op) \ 467 ".skip " __stringify(SETCC_ALIGN) " - (.-" #op "), 0xcc \n\t" 468 469 __FOP_START(setcc, SETCC_ALIGN) 470 FOP_SETCC(seto) 471 FOP_SETCC(setno) 472 FOP_SETCC(setc) 473 FOP_SETCC(setnc) 474 FOP_SETCC(setz) 475 FOP_SETCC(setnz) 476 FOP_SETCC(setbe) 477 FOP_SETCC(setnbe) 478 FOP_SETCC(sets) 479 FOP_SETCC(setns) 480 FOP_SETCC(setp) 481 FOP_SETCC(setnp) 482 FOP_SETCC(setl) 483 FOP_SETCC(setnl) 484 FOP_SETCC(setle) 485 FOP_SETCC(setnle) 486 FOP_END; 487 488 FOP_START(salc) 489 FOP_FUNC(salc) 490 "pushf; sbb %al, %al; popf \n\t" 491 FOP_RET(salc) 492 FOP_END; 493 494 /* 495 * XXX: inoutclob user must know where the argument is being expanded. 496 * Relying on CONFIG_CC_HAS_ASM_GOTO would allow us to remove _fault. 497 */ 498 #define asm_safe(insn, inoutclob...) \ 499 ({ \ 500 int _fault = 0; \ 501 \ 502 asm volatile("1:" insn "\n" \ 503 "2:\n" \ 504 _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_ONE_REG, %[_fault]) \ 505 : [_fault] "+r"(_fault) inoutclob ); \ 506 \ 507 _fault ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; \ 508 }) 509 510 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt, 511 enum x86_intercept intercept, 512 enum x86_intercept_stage stage) 513 { 514 struct x86_instruction_info info = { 515 .intercept = intercept, 516 .rep_prefix = ctxt->rep_prefix, 517 .modrm_mod = ctxt->modrm_mod, 518 .modrm_reg = ctxt->modrm_reg, 519 .modrm_rm = ctxt->modrm_rm, 520 .src_val = ctxt->src.val64, 521 .dst_val = ctxt->dst.val64, 522 .src_bytes = ctxt->src.bytes, 523 .dst_bytes = ctxt->dst.bytes, 524 .ad_bytes = ctxt->ad_bytes, 525 .next_rip = ctxt->eip, 526 }; 527 528 return ctxt->ops->intercept(ctxt, &info, stage); 529 } 530 531 static void assign_masked(ulong *dest, ulong src, ulong mask) 532 { 533 *dest = (*dest & ~mask) | (src & mask); 534 } 535 536 static void assign_register(unsigned long *reg, u64 val, int bytes) 537 { 538 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */ 539 switch (bytes) { 540 case 1: 541 *(u8 *)reg = (u8)val; 542 break; 543 case 2: 544 *(u16 *)reg = (u16)val; 545 break; 546 case 4: 547 *reg = (u32)val; 548 break; /* 64b: zero-extend */ 549 case 8: 550 *reg = val; 551 break; 552 } 553 } 554 555 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt) 556 { 557 return (1UL << (ctxt->ad_bytes << 3)) - 1; 558 } 559 560 static ulong stack_mask(struct x86_emulate_ctxt *ctxt) 561 { 562 u16 sel; 563 struct desc_struct ss; 564 565 if (ctxt->mode == X86EMUL_MODE_PROT64) 566 return ~0UL; 567 ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS); 568 return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */ 569 } 570 571 static int stack_size(struct x86_emulate_ctxt *ctxt) 572 { 573 return (__fls(stack_mask(ctxt)) + 1) >> 3; 574 } 575 576 /* Access/update address held in a register, based on addressing mode. */ 577 static inline unsigned long 578 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg) 579 { 580 if (ctxt->ad_bytes == sizeof(unsigned long)) 581 return reg; 582 else 583 return reg & ad_mask(ctxt); 584 } 585 586 static inline unsigned long 587 register_address(struct x86_emulate_ctxt *ctxt, int reg) 588 { 589 return address_mask(ctxt, reg_read(ctxt, reg)); 590 } 591 592 static void masked_increment(ulong *reg, ulong mask, int inc) 593 { 594 assign_masked(reg, *reg + inc, mask); 595 } 596 597 static inline void 598 register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc) 599 { 600 ulong *preg = reg_rmw(ctxt, reg); 601 602 assign_register(preg, *preg + inc, ctxt->ad_bytes); 603 } 604 605 static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc) 606 { 607 masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc); 608 } 609 610 static u32 desc_limit_scaled(struct desc_struct *desc) 611 { 612 u32 limit = get_desc_limit(desc); 613 614 return desc->g ? (limit << 12) | 0xfff : limit; 615 } 616 617 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) 618 { 619 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) 620 return 0; 621 622 return ctxt->ops->get_cached_segment_base(ctxt, seg); 623 } 624 625 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, 626 u32 error, bool valid) 627 { 628 if (KVM_EMULATOR_BUG_ON(vec > 0x1f, ctxt)) 629 return X86EMUL_UNHANDLEABLE; 630 631 ctxt->exception.vector = vec; 632 ctxt->exception.error_code = error; 633 ctxt->exception.error_code_valid = valid; 634 return X86EMUL_PROPAGATE_FAULT; 635 } 636 637 static int emulate_db(struct x86_emulate_ctxt *ctxt) 638 { 639 return emulate_exception(ctxt, DB_VECTOR, 0, false); 640 } 641 642 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) 643 { 644 return emulate_exception(ctxt, GP_VECTOR, err, true); 645 } 646 647 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err) 648 { 649 return emulate_exception(ctxt, SS_VECTOR, err, true); 650 } 651 652 static int emulate_ud(struct x86_emulate_ctxt *ctxt) 653 { 654 return emulate_exception(ctxt, UD_VECTOR, 0, false); 655 } 656 657 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err) 658 { 659 return emulate_exception(ctxt, TS_VECTOR, err, true); 660 } 661 662 static int emulate_de(struct x86_emulate_ctxt *ctxt) 663 { 664 return emulate_exception(ctxt, DE_VECTOR, 0, false); 665 } 666 667 static int emulate_nm(struct x86_emulate_ctxt *ctxt) 668 { 669 return emulate_exception(ctxt, NM_VECTOR, 0, false); 670 } 671 672 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg) 673 { 674 u16 selector; 675 struct desc_struct desc; 676 677 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg); 678 return selector; 679 } 680 681 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector, 682 unsigned seg) 683 { 684 u16 dummy; 685 u32 base3; 686 struct desc_struct desc; 687 688 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg); 689 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg); 690 } 691 692 static inline u8 ctxt_virt_addr_bits(struct x86_emulate_ctxt *ctxt) 693 { 694 return (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_LA57) ? 57 : 48; 695 } 696 697 static inline bool emul_is_noncanonical_address(u64 la, 698 struct x86_emulate_ctxt *ctxt) 699 { 700 return !__is_canonical_address(la, ctxt_virt_addr_bits(ctxt)); 701 } 702 703 /* 704 * x86 defines three classes of vector instructions: explicitly 705 * aligned, explicitly unaligned, and the rest, which change behaviour 706 * depending on whether they're AVX encoded or not. 707 * 708 * Also included is CMPXCHG16B which is not a vector instruction, yet it is 709 * subject to the same check. FXSAVE and FXRSTOR are checked here too as their 710 * 512 bytes of data must be aligned to a 16 byte boundary. 711 */ 712 static unsigned insn_alignment(struct x86_emulate_ctxt *ctxt, unsigned size) 713 { 714 u64 alignment = ctxt->d & AlignMask; 715 716 if (likely(size < 16)) 717 return 1; 718 719 switch (alignment) { 720 case Unaligned: 721 case Avx: 722 return 1; 723 case Aligned16: 724 return 16; 725 case Aligned: 726 default: 727 return size; 728 } 729 } 730 731 static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, 732 struct segmented_address addr, 733 unsigned *max_size, unsigned size, 734 bool write, bool fetch, 735 enum x86emul_mode mode, ulong *linear) 736 { 737 struct desc_struct desc; 738 bool usable; 739 ulong la; 740 u32 lim; 741 u16 sel; 742 u8 va_bits; 743 744 la = seg_base(ctxt, addr.seg) + addr.ea; 745 *max_size = 0; 746 switch (mode) { 747 case X86EMUL_MODE_PROT64: 748 *linear = la; 749 va_bits = ctxt_virt_addr_bits(ctxt); 750 if (!__is_canonical_address(la, va_bits)) 751 goto bad; 752 753 *max_size = min_t(u64, ~0u, (1ull << va_bits) - la); 754 if (size > *max_size) 755 goto bad; 756 break; 757 default: 758 *linear = la = (u32)la; 759 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL, 760 addr.seg); 761 if (!usable) 762 goto bad; 763 /* code segment in protected mode or read-only data segment */ 764 if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8)) 765 || !(desc.type & 2)) && write) 766 goto bad; 767 /* unreadable code segment */ 768 if (!fetch && (desc.type & 8) && !(desc.type & 2)) 769 goto bad; 770 lim = desc_limit_scaled(&desc); 771 if (!(desc.type & 8) && (desc.type & 4)) { 772 /* expand-down segment */ 773 if (addr.ea <= lim) 774 goto bad; 775 lim = desc.d ? 0xffffffff : 0xffff; 776 } 777 if (addr.ea > lim) 778 goto bad; 779 if (lim == 0xffffffff) 780 *max_size = ~0u; 781 else { 782 *max_size = (u64)lim + 1 - addr.ea; 783 if (size > *max_size) 784 goto bad; 785 } 786 break; 787 } 788 if (la & (insn_alignment(ctxt, size) - 1)) 789 return emulate_gp(ctxt, 0); 790 return X86EMUL_CONTINUE; 791 bad: 792 if (addr.seg == VCPU_SREG_SS) 793 return emulate_ss(ctxt, 0); 794 else 795 return emulate_gp(ctxt, 0); 796 } 797 798 static int linearize(struct x86_emulate_ctxt *ctxt, 799 struct segmented_address addr, 800 unsigned size, bool write, 801 ulong *linear) 802 { 803 unsigned max_size; 804 return __linearize(ctxt, addr, &max_size, size, write, false, 805 ctxt->mode, linear); 806 } 807 808 static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst, 809 enum x86emul_mode mode) 810 { 811 ulong linear; 812 int rc; 813 unsigned max_size; 814 struct segmented_address addr = { .seg = VCPU_SREG_CS, 815 .ea = dst }; 816 817 if (ctxt->op_bytes != sizeof(unsigned long)) 818 addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1); 819 rc = __linearize(ctxt, addr, &max_size, 1, false, true, mode, &linear); 820 if (rc == X86EMUL_CONTINUE) 821 ctxt->_eip = addr.ea; 822 return rc; 823 } 824 825 static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst) 826 { 827 return assign_eip(ctxt, dst, ctxt->mode); 828 } 829 830 static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst, 831 const struct desc_struct *cs_desc) 832 { 833 enum x86emul_mode mode = ctxt->mode; 834 int rc; 835 836 #ifdef CONFIG_X86_64 837 if (ctxt->mode >= X86EMUL_MODE_PROT16) { 838 if (cs_desc->l) { 839 u64 efer = 0; 840 841 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 842 if (efer & EFER_LMA) 843 mode = X86EMUL_MODE_PROT64; 844 } else 845 mode = X86EMUL_MODE_PROT32; /* temporary value */ 846 } 847 #endif 848 if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32) 849 mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; 850 rc = assign_eip(ctxt, dst, mode); 851 if (rc == X86EMUL_CONTINUE) 852 ctxt->mode = mode; 853 return rc; 854 } 855 856 static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) 857 { 858 return assign_eip_near(ctxt, ctxt->_eip + rel); 859 } 860 861 static int linear_read_system(struct x86_emulate_ctxt *ctxt, ulong linear, 862 void *data, unsigned size) 863 { 864 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, true); 865 } 866 867 static int linear_write_system(struct x86_emulate_ctxt *ctxt, 868 ulong linear, void *data, 869 unsigned int size) 870 { 871 return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, true); 872 } 873 874 static int segmented_read_std(struct x86_emulate_ctxt *ctxt, 875 struct segmented_address addr, 876 void *data, 877 unsigned size) 878 { 879 int rc; 880 ulong linear; 881 882 rc = linearize(ctxt, addr, size, false, &linear); 883 if (rc != X86EMUL_CONTINUE) 884 return rc; 885 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, false); 886 } 887 888 static int segmented_write_std(struct x86_emulate_ctxt *ctxt, 889 struct segmented_address addr, 890 void *data, 891 unsigned int size) 892 { 893 int rc; 894 ulong linear; 895 896 rc = linearize(ctxt, addr, size, true, &linear); 897 if (rc != X86EMUL_CONTINUE) 898 return rc; 899 return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, false); 900 } 901 902 /* 903 * Prefetch the remaining bytes of the instruction without crossing page 904 * boundary if they are not in fetch_cache yet. 905 */ 906 static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size) 907 { 908 int rc; 909 unsigned size, max_size; 910 unsigned long linear; 911 int cur_size = ctxt->fetch.end - ctxt->fetch.data; 912 struct segmented_address addr = { .seg = VCPU_SREG_CS, 913 .ea = ctxt->eip + cur_size }; 914 915 /* 916 * We do not know exactly how many bytes will be needed, and 917 * __linearize is expensive, so fetch as much as possible. We 918 * just have to avoid going beyond the 15 byte limit, the end 919 * of the segment, or the end of the page. 920 * 921 * __linearize is called with size 0 so that it does not do any 922 * boundary check itself. Instead, we use max_size to check 923 * against op_size. 924 */ 925 rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode, 926 &linear); 927 if (unlikely(rc != X86EMUL_CONTINUE)) 928 return rc; 929 930 size = min_t(unsigned, 15UL ^ cur_size, max_size); 931 size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear)); 932 933 /* 934 * One instruction can only straddle two pages, 935 * and one has been loaded at the beginning of 936 * x86_decode_insn. So, if not enough bytes 937 * still, we must have hit the 15-byte boundary. 938 */ 939 if (unlikely(size < op_size)) 940 return emulate_gp(ctxt, 0); 941 942 rc = ctxt->ops->fetch(ctxt, linear, ctxt->fetch.end, 943 size, &ctxt->exception); 944 if (unlikely(rc != X86EMUL_CONTINUE)) 945 return rc; 946 ctxt->fetch.end += size; 947 return X86EMUL_CONTINUE; 948 } 949 950 static __always_inline int do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, 951 unsigned size) 952 { 953 unsigned done_size = ctxt->fetch.end - ctxt->fetch.ptr; 954 955 if (unlikely(done_size < size)) 956 return __do_insn_fetch_bytes(ctxt, size - done_size); 957 else 958 return X86EMUL_CONTINUE; 959 } 960 961 /* Fetch next part of the instruction being emulated. */ 962 #define insn_fetch(_type, _ctxt) \ 963 ({ _type _x; \ 964 \ 965 rc = do_insn_fetch_bytes(_ctxt, sizeof(_type)); \ 966 if (rc != X86EMUL_CONTINUE) \ 967 goto done; \ 968 ctxt->_eip += sizeof(_type); \ 969 memcpy(&_x, ctxt->fetch.ptr, sizeof(_type)); \ 970 ctxt->fetch.ptr += sizeof(_type); \ 971 _x; \ 972 }) 973 974 #define insn_fetch_arr(_arr, _size, _ctxt) \ 975 ({ \ 976 rc = do_insn_fetch_bytes(_ctxt, _size); \ 977 if (rc != X86EMUL_CONTINUE) \ 978 goto done; \ 979 ctxt->_eip += (_size); \ 980 memcpy(_arr, ctxt->fetch.ptr, _size); \ 981 ctxt->fetch.ptr += (_size); \ 982 }) 983 984 /* 985 * Given the 'reg' portion of a ModRM byte, and a register block, return a 986 * pointer into the block that addresses the relevant register. 987 * @highbyte_regs specifies whether to decode AH,CH,DH,BH. 988 */ 989 static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, 990 int byteop) 991 { 992 void *p; 993 int highbyte_regs = (ctxt->rex_prefix == 0) && byteop; 994 995 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) 996 p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1; 997 else 998 p = reg_rmw(ctxt, modrm_reg); 999 return p; 1000 } 1001 1002 static int read_descriptor(struct x86_emulate_ctxt *ctxt, 1003 struct segmented_address addr, 1004 u16 *size, unsigned long *address, int op_bytes) 1005 { 1006 int rc; 1007 1008 if (op_bytes == 2) 1009 op_bytes = 3; 1010 *address = 0; 1011 rc = segmented_read_std(ctxt, addr, size, 2); 1012 if (rc != X86EMUL_CONTINUE) 1013 return rc; 1014 addr.ea += 2; 1015 rc = segmented_read_std(ctxt, addr, address, op_bytes); 1016 return rc; 1017 } 1018 1019 FASTOP2(add); 1020 FASTOP2(or); 1021 FASTOP2(adc); 1022 FASTOP2(sbb); 1023 FASTOP2(and); 1024 FASTOP2(sub); 1025 FASTOP2(xor); 1026 FASTOP2(cmp); 1027 FASTOP2(test); 1028 1029 FASTOP1SRC2(mul, mul_ex); 1030 FASTOP1SRC2(imul, imul_ex); 1031 FASTOP1SRC2EX(div, div_ex); 1032 FASTOP1SRC2EX(idiv, idiv_ex); 1033 1034 FASTOP3WCL(shld); 1035 FASTOP3WCL(shrd); 1036 1037 FASTOP2W(imul); 1038 1039 FASTOP1(not); 1040 FASTOP1(neg); 1041 FASTOP1(inc); 1042 FASTOP1(dec); 1043 1044 FASTOP2CL(rol); 1045 FASTOP2CL(ror); 1046 FASTOP2CL(rcl); 1047 FASTOP2CL(rcr); 1048 FASTOP2CL(shl); 1049 FASTOP2CL(shr); 1050 FASTOP2CL(sar); 1051 1052 FASTOP2W(bsf); 1053 FASTOP2W(bsr); 1054 FASTOP2W(bt); 1055 FASTOP2W(bts); 1056 FASTOP2W(btr); 1057 FASTOP2W(btc); 1058 1059 FASTOP2(xadd); 1060 1061 FASTOP2R(cmp, cmp_r); 1062 1063 static int em_bsf_c(struct x86_emulate_ctxt *ctxt) 1064 { 1065 /* If src is zero, do not writeback, but update flags */ 1066 if (ctxt->src.val == 0) 1067 ctxt->dst.type = OP_NONE; 1068 return fastop(ctxt, em_bsf); 1069 } 1070 1071 static int em_bsr_c(struct x86_emulate_ctxt *ctxt) 1072 { 1073 /* If src is zero, do not writeback, but update flags */ 1074 if (ctxt->src.val == 0) 1075 ctxt->dst.type = OP_NONE; 1076 return fastop(ctxt, em_bsr); 1077 } 1078 1079 static __always_inline u8 test_cc(unsigned int condition, unsigned long flags) 1080 { 1081 u8 rc; 1082 void (*fop)(void) = (void *)em_setcc + SETCC_ALIGN * (condition & 0xf); 1083 1084 flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; 1085 asm("push %[flags]; popf; " CALL_NOSPEC 1086 : "=a"(rc) : [thunk_target]"r"(fop), [flags]"r"(flags)); 1087 return rc; 1088 } 1089 1090 static void fetch_register_operand(struct operand *op) 1091 { 1092 switch (op->bytes) { 1093 case 1: 1094 op->val = *(u8 *)op->addr.reg; 1095 break; 1096 case 2: 1097 op->val = *(u16 *)op->addr.reg; 1098 break; 1099 case 4: 1100 op->val = *(u32 *)op->addr.reg; 1101 break; 1102 case 8: 1103 op->val = *(u64 *)op->addr.reg; 1104 break; 1105 } 1106 } 1107 1108 static int em_fninit(struct x86_emulate_ctxt *ctxt) 1109 { 1110 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 1111 return emulate_nm(ctxt); 1112 1113 kvm_fpu_get(); 1114 asm volatile("fninit"); 1115 kvm_fpu_put(); 1116 return X86EMUL_CONTINUE; 1117 } 1118 1119 static int em_fnstcw(struct x86_emulate_ctxt *ctxt) 1120 { 1121 u16 fcw; 1122 1123 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 1124 return emulate_nm(ctxt); 1125 1126 kvm_fpu_get(); 1127 asm volatile("fnstcw %0": "+m"(fcw)); 1128 kvm_fpu_put(); 1129 1130 ctxt->dst.val = fcw; 1131 1132 return X86EMUL_CONTINUE; 1133 } 1134 1135 static int em_fnstsw(struct x86_emulate_ctxt *ctxt) 1136 { 1137 u16 fsw; 1138 1139 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 1140 return emulate_nm(ctxt); 1141 1142 kvm_fpu_get(); 1143 asm volatile("fnstsw %0": "+m"(fsw)); 1144 kvm_fpu_put(); 1145 1146 ctxt->dst.val = fsw; 1147 1148 return X86EMUL_CONTINUE; 1149 } 1150 1151 static void decode_register_operand(struct x86_emulate_ctxt *ctxt, 1152 struct operand *op) 1153 { 1154 unsigned reg = ctxt->modrm_reg; 1155 1156 if (!(ctxt->d & ModRM)) 1157 reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3); 1158 1159 if (ctxt->d & Sse) { 1160 op->type = OP_XMM; 1161 op->bytes = 16; 1162 op->addr.xmm = reg; 1163 kvm_read_sse_reg(reg, &op->vec_val); 1164 return; 1165 } 1166 if (ctxt->d & Mmx) { 1167 reg &= 7; 1168 op->type = OP_MM; 1169 op->bytes = 8; 1170 op->addr.mm = reg; 1171 return; 1172 } 1173 1174 op->type = OP_REG; 1175 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 1176 op->addr.reg = decode_register(ctxt, reg, ctxt->d & ByteOp); 1177 1178 fetch_register_operand(op); 1179 op->orig_val = op->val; 1180 } 1181 1182 static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg) 1183 { 1184 if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP) 1185 ctxt->modrm_seg = VCPU_SREG_SS; 1186 } 1187 1188 static int decode_modrm(struct x86_emulate_ctxt *ctxt, 1189 struct operand *op) 1190 { 1191 u8 sib; 1192 int index_reg, base_reg, scale; 1193 int rc = X86EMUL_CONTINUE; 1194 ulong modrm_ea = 0; 1195 1196 ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8); /* REX.R */ 1197 index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */ 1198 base_reg = (ctxt->rex_prefix << 3) & 8; /* REX.B */ 1199 1200 ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6; 1201 ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; 1202 ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07); 1203 ctxt->modrm_seg = VCPU_SREG_DS; 1204 1205 if (ctxt->modrm_mod == 3 || (ctxt->d & NoMod)) { 1206 op->type = OP_REG; 1207 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 1208 op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, 1209 ctxt->d & ByteOp); 1210 if (ctxt->d & Sse) { 1211 op->type = OP_XMM; 1212 op->bytes = 16; 1213 op->addr.xmm = ctxt->modrm_rm; 1214 kvm_read_sse_reg(ctxt->modrm_rm, &op->vec_val); 1215 return rc; 1216 } 1217 if (ctxt->d & Mmx) { 1218 op->type = OP_MM; 1219 op->bytes = 8; 1220 op->addr.mm = ctxt->modrm_rm & 7; 1221 return rc; 1222 } 1223 fetch_register_operand(op); 1224 return rc; 1225 } 1226 1227 op->type = OP_MEM; 1228 1229 if (ctxt->ad_bytes == 2) { 1230 unsigned bx = reg_read(ctxt, VCPU_REGS_RBX); 1231 unsigned bp = reg_read(ctxt, VCPU_REGS_RBP); 1232 unsigned si = reg_read(ctxt, VCPU_REGS_RSI); 1233 unsigned di = reg_read(ctxt, VCPU_REGS_RDI); 1234 1235 /* 16-bit ModR/M decode. */ 1236 switch (ctxt->modrm_mod) { 1237 case 0: 1238 if (ctxt->modrm_rm == 6) 1239 modrm_ea += insn_fetch(u16, ctxt); 1240 break; 1241 case 1: 1242 modrm_ea += insn_fetch(s8, ctxt); 1243 break; 1244 case 2: 1245 modrm_ea += insn_fetch(u16, ctxt); 1246 break; 1247 } 1248 switch (ctxt->modrm_rm) { 1249 case 0: 1250 modrm_ea += bx + si; 1251 break; 1252 case 1: 1253 modrm_ea += bx + di; 1254 break; 1255 case 2: 1256 modrm_ea += bp + si; 1257 break; 1258 case 3: 1259 modrm_ea += bp + di; 1260 break; 1261 case 4: 1262 modrm_ea += si; 1263 break; 1264 case 5: 1265 modrm_ea += di; 1266 break; 1267 case 6: 1268 if (ctxt->modrm_mod != 0) 1269 modrm_ea += bp; 1270 break; 1271 case 7: 1272 modrm_ea += bx; 1273 break; 1274 } 1275 if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 || 1276 (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0)) 1277 ctxt->modrm_seg = VCPU_SREG_SS; 1278 modrm_ea = (u16)modrm_ea; 1279 } else { 1280 /* 32/64-bit ModR/M decode. */ 1281 if ((ctxt->modrm_rm & 7) == 4) { 1282 sib = insn_fetch(u8, ctxt); 1283 index_reg |= (sib >> 3) & 7; 1284 base_reg |= sib & 7; 1285 scale = sib >> 6; 1286 1287 if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0) 1288 modrm_ea += insn_fetch(s32, ctxt); 1289 else { 1290 modrm_ea += reg_read(ctxt, base_reg); 1291 adjust_modrm_seg(ctxt, base_reg); 1292 /* Increment ESP on POP [ESP] */ 1293 if ((ctxt->d & IncSP) && 1294 base_reg == VCPU_REGS_RSP) 1295 modrm_ea += ctxt->op_bytes; 1296 } 1297 if (index_reg != 4) 1298 modrm_ea += reg_read(ctxt, index_reg) << scale; 1299 } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) { 1300 modrm_ea += insn_fetch(s32, ctxt); 1301 if (ctxt->mode == X86EMUL_MODE_PROT64) 1302 ctxt->rip_relative = 1; 1303 } else { 1304 base_reg = ctxt->modrm_rm; 1305 modrm_ea += reg_read(ctxt, base_reg); 1306 adjust_modrm_seg(ctxt, base_reg); 1307 } 1308 switch (ctxt->modrm_mod) { 1309 case 1: 1310 modrm_ea += insn_fetch(s8, ctxt); 1311 break; 1312 case 2: 1313 modrm_ea += insn_fetch(s32, ctxt); 1314 break; 1315 } 1316 } 1317 op->addr.mem.ea = modrm_ea; 1318 if (ctxt->ad_bytes != 8) 1319 ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea; 1320 1321 done: 1322 return rc; 1323 } 1324 1325 static int decode_abs(struct x86_emulate_ctxt *ctxt, 1326 struct operand *op) 1327 { 1328 int rc = X86EMUL_CONTINUE; 1329 1330 op->type = OP_MEM; 1331 switch (ctxt->ad_bytes) { 1332 case 2: 1333 op->addr.mem.ea = insn_fetch(u16, ctxt); 1334 break; 1335 case 4: 1336 op->addr.mem.ea = insn_fetch(u32, ctxt); 1337 break; 1338 case 8: 1339 op->addr.mem.ea = insn_fetch(u64, ctxt); 1340 break; 1341 } 1342 done: 1343 return rc; 1344 } 1345 1346 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt) 1347 { 1348 long sv = 0, mask; 1349 1350 if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) { 1351 mask = ~((long)ctxt->dst.bytes * 8 - 1); 1352 1353 if (ctxt->src.bytes == 2) 1354 sv = (s16)ctxt->src.val & (s16)mask; 1355 else if (ctxt->src.bytes == 4) 1356 sv = (s32)ctxt->src.val & (s32)mask; 1357 else 1358 sv = (s64)ctxt->src.val & (s64)mask; 1359 1360 ctxt->dst.addr.mem.ea = address_mask(ctxt, 1361 ctxt->dst.addr.mem.ea + (sv >> 3)); 1362 } 1363 1364 /* only subword offset */ 1365 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1; 1366 } 1367 1368 static int read_emulated(struct x86_emulate_ctxt *ctxt, 1369 unsigned long addr, void *dest, unsigned size) 1370 { 1371 int rc; 1372 struct read_cache *mc = &ctxt->mem_read; 1373 1374 if (mc->pos < mc->end) 1375 goto read_cached; 1376 1377 if (KVM_EMULATOR_BUG_ON((mc->end + size) >= sizeof(mc->data), ctxt)) 1378 return X86EMUL_UNHANDLEABLE; 1379 1380 rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size, 1381 &ctxt->exception); 1382 if (rc != X86EMUL_CONTINUE) 1383 return rc; 1384 1385 mc->end += size; 1386 1387 read_cached: 1388 memcpy(dest, mc->data + mc->pos, size); 1389 mc->pos += size; 1390 return X86EMUL_CONTINUE; 1391 } 1392 1393 static int segmented_read(struct x86_emulate_ctxt *ctxt, 1394 struct segmented_address addr, 1395 void *data, 1396 unsigned size) 1397 { 1398 int rc; 1399 ulong linear; 1400 1401 rc = linearize(ctxt, addr, size, false, &linear); 1402 if (rc != X86EMUL_CONTINUE) 1403 return rc; 1404 return read_emulated(ctxt, linear, data, size); 1405 } 1406 1407 static int segmented_write(struct x86_emulate_ctxt *ctxt, 1408 struct segmented_address addr, 1409 const void *data, 1410 unsigned size) 1411 { 1412 int rc; 1413 ulong linear; 1414 1415 rc = linearize(ctxt, addr, size, true, &linear); 1416 if (rc != X86EMUL_CONTINUE) 1417 return rc; 1418 return ctxt->ops->write_emulated(ctxt, linear, data, size, 1419 &ctxt->exception); 1420 } 1421 1422 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt, 1423 struct segmented_address addr, 1424 const void *orig_data, const void *data, 1425 unsigned size) 1426 { 1427 int rc; 1428 ulong linear; 1429 1430 rc = linearize(ctxt, addr, size, true, &linear); 1431 if (rc != X86EMUL_CONTINUE) 1432 return rc; 1433 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data, 1434 size, &ctxt->exception); 1435 } 1436 1437 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, 1438 unsigned int size, unsigned short port, 1439 void *dest) 1440 { 1441 struct read_cache *rc = &ctxt->io_read; 1442 1443 if (rc->pos == rc->end) { /* refill pio read ahead */ 1444 unsigned int in_page, n; 1445 unsigned int count = ctxt->rep_prefix ? 1446 address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1; 1447 in_page = (ctxt->eflags & X86_EFLAGS_DF) ? 1448 offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) : 1449 PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)); 1450 n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count); 1451 if (n == 0) 1452 n = 1; 1453 rc->pos = rc->end = 0; 1454 if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n)) 1455 return 0; 1456 rc->end = n * size; 1457 } 1458 1459 if (ctxt->rep_prefix && (ctxt->d & String) && 1460 !(ctxt->eflags & X86_EFLAGS_DF)) { 1461 ctxt->dst.data = rc->data + rc->pos; 1462 ctxt->dst.type = OP_MEM_STR; 1463 ctxt->dst.count = (rc->end - rc->pos) / size; 1464 rc->pos = rc->end; 1465 } else { 1466 memcpy(dest, rc->data + rc->pos, size); 1467 rc->pos += size; 1468 } 1469 return 1; 1470 } 1471 1472 static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt, 1473 u16 index, struct desc_struct *desc) 1474 { 1475 struct desc_ptr dt; 1476 ulong addr; 1477 1478 ctxt->ops->get_idt(ctxt, &dt); 1479 1480 if (dt.size < index * 8 + 7) 1481 return emulate_gp(ctxt, index << 3 | 0x2); 1482 1483 addr = dt.address + index * 8; 1484 return linear_read_system(ctxt, addr, desc, sizeof(*desc)); 1485 } 1486 1487 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, 1488 u16 selector, struct desc_ptr *dt) 1489 { 1490 const struct x86_emulate_ops *ops = ctxt->ops; 1491 u32 base3 = 0; 1492 1493 if (selector & 1 << 2) { 1494 struct desc_struct desc; 1495 u16 sel; 1496 1497 memset(dt, 0, sizeof(*dt)); 1498 if (!ops->get_segment(ctxt, &sel, &desc, &base3, 1499 VCPU_SREG_LDTR)) 1500 return; 1501 1502 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ 1503 dt->address = get_desc_base(&desc) | ((u64)base3 << 32); 1504 } else 1505 ops->get_gdt(ctxt, dt); 1506 } 1507 1508 static int get_descriptor_ptr(struct x86_emulate_ctxt *ctxt, 1509 u16 selector, ulong *desc_addr_p) 1510 { 1511 struct desc_ptr dt; 1512 u16 index = selector >> 3; 1513 ulong addr; 1514 1515 get_descriptor_table_ptr(ctxt, selector, &dt); 1516 1517 if (dt.size < index * 8 + 7) 1518 return emulate_gp(ctxt, selector & 0xfffc); 1519 1520 addr = dt.address + index * 8; 1521 1522 #ifdef CONFIG_X86_64 1523 if (addr >> 32 != 0) { 1524 u64 efer = 0; 1525 1526 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 1527 if (!(efer & EFER_LMA)) 1528 addr &= (u32)-1; 1529 } 1530 #endif 1531 1532 *desc_addr_p = addr; 1533 return X86EMUL_CONTINUE; 1534 } 1535 1536 /* allowed just for 8 bytes segments */ 1537 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1538 u16 selector, struct desc_struct *desc, 1539 ulong *desc_addr_p) 1540 { 1541 int rc; 1542 1543 rc = get_descriptor_ptr(ctxt, selector, desc_addr_p); 1544 if (rc != X86EMUL_CONTINUE) 1545 return rc; 1546 1547 return linear_read_system(ctxt, *desc_addr_p, desc, sizeof(*desc)); 1548 } 1549 1550 /* allowed just for 8 bytes segments */ 1551 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1552 u16 selector, struct desc_struct *desc) 1553 { 1554 int rc; 1555 ulong addr; 1556 1557 rc = get_descriptor_ptr(ctxt, selector, &addr); 1558 if (rc != X86EMUL_CONTINUE) 1559 return rc; 1560 1561 return linear_write_system(ctxt, addr, desc, sizeof(*desc)); 1562 } 1563 1564 static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1565 u16 selector, int seg, u8 cpl, 1566 enum x86_transfer_type transfer, 1567 struct desc_struct *desc) 1568 { 1569 struct desc_struct seg_desc, old_desc; 1570 u8 dpl, rpl; 1571 unsigned err_vec = GP_VECTOR; 1572 u32 err_code = 0; 1573 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ 1574 ulong desc_addr; 1575 int ret; 1576 u16 dummy; 1577 u32 base3 = 0; 1578 1579 memset(&seg_desc, 0, sizeof(seg_desc)); 1580 1581 if (ctxt->mode == X86EMUL_MODE_REAL) { 1582 /* set real mode segment descriptor (keep limit etc. for 1583 * unreal mode) */ 1584 ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg); 1585 set_desc_base(&seg_desc, selector << 4); 1586 goto load; 1587 } else if (seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) { 1588 /* VM86 needs a clean new segment descriptor */ 1589 set_desc_base(&seg_desc, selector << 4); 1590 set_desc_limit(&seg_desc, 0xffff); 1591 seg_desc.type = 3; 1592 seg_desc.p = 1; 1593 seg_desc.s = 1; 1594 seg_desc.dpl = 3; 1595 goto load; 1596 } 1597 1598 rpl = selector & 3; 1599 1600 /* TR should be in GDT only */ 1601 if (seg == VCPU_SREG_TR && (selector & (1 << 2))) 1602 goto exception; 1603 1604 /* NULL selector is not valid for TR, CS and (except for long mode) SS */ 1605 if (null_selector) { 1606 if (seg == VCPU_SREG_CS || seg == VCPU_SREG_TR) 1607 goto exception; 1608 1609 if (seg == VCPU_SREG_SS) { 1610 if (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl) 1611 goto exception; 1612 1613 /* 1614 * ctxt->ops->set_segment expects the CPL to be in 1615 * SS.DPL, so fake an expand-up 32-bit data segment. 1616 */ 1617 seg_desc.type = 3; 1618 seg_desc.p = 1; 1619 seg_desc.s = 1; 1620 seg_desc.dpl = cpl; 1621 seg_desc.d = 1; 1622 seg_desc.g = 1; 1623 } 1624 1625 /* Skip all following checks */ 1626 goto load; 1627 } 1628 1629 ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr); 1630 if (ret != X86EMUL_CONTINUE) 1631 return ret; 1632 1633 err_code = selector & 0xfffc; 1634 err_vec = (transfer == X86_TRANSFER_TASK_SWITCH) ? TS_VECTOR : 1635 GP_VECTOR; 1636 1637 /* can't load system descriptor into segment selector */ 1638 if (seg <= VCPU_SREG_GS && !seg_desc.s) { 1639 if (transfer == X86_TRANSFER_CALL_JMP) 1640 return X86EMUL_UNHANDLEABLE; 1641 goto exception; 1642 } 1643 1644 dpl = seg_desc.dpl; 1645 1646 switch (seg) { 1647 case VCPU_SREG_SS: 1648 /* 1649 * segment is not a writable data segment or segment 1650 * selector's RPL != CPL or segment selector's RPL != CPL 1651 */ 1652 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) 1653 goto exception; 1654 break; 1655 case VCPU_SREG_CS: 1656 if (!(seg_desc.type & 8)) 1657 goto exception; 1658 1659 if (transfer == X86_TRANSFER_RET) { 1660 /* RET can never return to an inner privilege level. */ 1661 if (rpl < cpl) 1662 goto exception; 1663 /* Outer-privilege level return is not implemented */ 1664 if (rpl > cpl) 1665 return X86EMUL_UNHANDLEABLE; 1666 } 1667 if (transfer == X86_TRANSFER_RET || transfer == X86_TRANSFER_TASK_SWITCH) { 1668 if (seg_desc.type & 4) { 1669 /* conforming */ 1670 if (dpl > rpl) 1671 goto exception; 1672 } else { 1673 /* nonconforming */ 1674 if (dpl != rpl) 1675 goto exception; 1676 } 1677 } else { /* X86_TRANSFER_CALL_JMP */ 1678 if (seg_desc.type & 4) { 1679 /* conforming */ 1680 if (dpl > cpl) 1681 goto exception; 1682 } else { 1683 /* nonconforming */ 1684 if (rpl > cpl || dpl != cpl) 1685 goto exception; 1686 } 1687 } 1688 /* in long-mode d/b must be clear if l is set */ 1689 if (seg_desc.d && seg_desc.l) { 1690 u64 efer = 0; 1691 1692 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 1693 if (efer & EFER_LMA) 1694 goto exception; 1695 } 1696 1697 /* CS(RPL) <- CPL */ 1698 selector = (selector & 0xfffc) | cpl; 1699 break; 1700 case VCPU_SREG_TR: 1701 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) 1702 goto exception; 1703 break; 1704 case VCPU_SREG_LDTR: 1705 if (seg_desc.s || seg_desc.type != 2) 1706 goto exception; 1707 break; 1708 default: /* DS, ES, FS, or GS */ 1709 /* 1710 * segment is not a data or readable code segment or 1711 * ((segment is a data or nonconforming code segment) 1712 * and (both RPL and CPL > DPL)) 1713 */ 1714 if ((seg_desc.type & 0xa) == 0x8 || 1715 (((seg_desc.type & 0xc) != 0xc) && 1716 (rpl > dpl && cpl > dpl))) 1717 goto exception; 1718 break; 1719 } 1720 1721 if (!seg_desc.p) { 1722 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; 1723 goto exception; 1724 } 1725 1726 if (seg_desc.s) { 1727 /* mark segment as accessed */ 1728 if (!(seg_desc.type & 1)) { 1729 seg_desc.type |= 1; 1730 ret = write_segment_descriptor(ctxt, selector, 1731 &seg_desc); 1732 if (ret != X86EMUL_CONTINUE) 1733 return ret; 1734 } 1735 } else if (ctxt->mode == X86EMUL_MODE_PROT64) { 1736 ret = linear_read_system(ctxt, desc_addr+8, &base3, sizeof(base3)); 1737 if (ret != X86EMUL_CONTINUE) 1738 return ret; 1739 if (emul_is_noncanonical_address(get_desc_base(&seg_desc) | 1740 ((u64)base3 << 32), ctxt)) 1741 return emulate_gp(ctxt, err_code); 1742 } 1743 1744 if (seg == VCPU_SREG_TR) { 1745 old_desc = seg_desc; 1746 seg_desc.type |= 2; /* busy */ 1747 ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc, 1748 sizeof(seg_desc), &ctxt->exception); 1749 if (ret != X86EMUL_CONTINUE) 1750 return ret; 1751 } 1752 load: 1753 ctxt->ops->set_segment(ctxt, selector, &seg_desc, base3, seg); 1754 if (desc) 1755 *desc = seg_desc; 1756 return X86EMUL_CONTINUE; 1757 exception: 1758 return emulate_exception(ctxt, err_vec, err_code, true); 1759 } 1760 1761 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1762 u16 selector, int seg) 1763 { 1764 u8 cpl = ctxt->ops->cpl(ctxt); 1765 1766 /* 1767 * None of MOV, POP and LSS can load a NULL selector in CPL=3, but 1768 * they can load it at CPL<3 (Intel's manual says only LSS can, 1769 * but it's wrong). 1770 * 1771 * However, the Intel manual says that putting IST=1/DPL=3 in 1772 * an interrupt gate will result in SS=3 (the AMD manual instead 1773 * says it doesn't), so allow SS=3 in __load_segment_descriptor 1774 * and only forbid it here. 1775 */ 1776 if (seg == VCPU_SREG_SS && selector == 3 && 1777 ctxt->mode == X86EMUL_MODE_PROT64) 1778 return emulate_exception(ctxt, GP_VECTOR, 0, true); 1779 1780 return __load_segment_descriptor(ctxt, selector, seg, cpl, 1781 X86_TRANSFER_NONE, NULL); 1782 } 1783 1784 static void write_register_operand(struct operand *op) 1785 { 1786 return assign_register(op->addr.reg, op->val, op->bytes); 1787 } 1788 1789 static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op) 1790 { 1791 switch (op->type) { 1792 case OP_REG: 1793 write_register_operand(op); 1794 break; 1795 case OP_MEM: 1796 if (ctxt->lock_prefix) 1797 return segmented_cmpxchg(ctxt, 1798 op->addr.mem, 1799 &op->orig_val, 1800 &op->val, 1801 op->bytes); 1802 else 1803 return segmented_write(ctxt, 1804 op->addr.mem, 1805 &op->val, 1806 op->bytes); 1807 break; 1808 case OP_MEM_STR: 1809 return segmented_write(ctxt, 1810 op->addr.mem, 1811 op->data, 1812 op->bytes * op->count); 1813 break; 1814 case OP_XMM: 1815 kvm_write_sse_reg(op->addr.xmm, &op->vec_val); 1816 break; 1817 case OP_MM: 1818 kvm_write_mmx_reg(op->addr.mm, &op->mm_val); 1819 break; 1820 case OP_NONE: 1821 /* no writeback */ 1822 break; 1823 default: 1824 break; 1825 } 1826 return X86EMUL_CONTINUE; 1827 } 1828 1829 static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes) 1830 { 1831 struct segmented_address addr; 1832 1833 rsp_increment(ctxt, -bytes); 1834 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); 1835 addr.seg = VCPU_SREG_SS; 1836 1837 return segmented_write(ctxt, addr, data, bytes); 1838 } 1839 1840 static int em_push(struct x86_emulate_ctxt *ctxt) 1841 { 1842 /* Disable writeback. */ 1843 ctxt->dst.type = OP_NONE; 1844 return push(ctxt, &ctxt->src.val, ctxt->op_bytes); 1845 } 1846 1847 static int emulate_pop(struct x86_emulate_ctxt *ctxt, 1848 void *dest, int len) 1849 { 1850 int rc; 1851 struct segmented_address addr; 1852 1853 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); 1854 addr.seg = VCPU_SREG_SS; 1855 rc = segmented_read(ctxt, addr, dest, len); 1856 if (rc != X86EMUL_CONTINUE) 1857 return rc; 1858 1859 rsp_increment(ctxt, len); 1860 return rc; 1861 } 1862 1863 static int em_pop(struct x86_emulate_ctxt *ctxt) 1864 { 1865 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes); 1866 } 1867 1868 static int emulate_popf(struct x86_emulate_ctxt *ctxt, 1869 void *dest, int len) 1870 { 1871 int rc; 1872 unsigned long val, change_mask; 1873 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT; 1874 int cpl = ctxt->ops->cpl(ctxt); 1875 1876 rc = emulate_pop(ctxt, &val, len); 1877 if (rc != X86EMUL_CONTINUE) 1878 return rc; 1879 1880 change_mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | 1881 X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_OF | 1882 X86_EFLAGS_TF | X86_EFLAGS_DF | X86_EFLAGS_NT | 1883 X86_EFLAGS_AC | X86_EFLAGS_ID; 1884 1885 switch(ctxt->mode) { 1886 case X86EMUL_MODE_PROT64: 1887 case X86EMUL_MODE_PROT32: 1888 case X86EMUL_MODE_PROT16: 1889 if (cpl == 0) 1890 change_mask |= X86_EFLAGS_IOPL; 1891 if (cpl <= iopl) 1892 change_mask |= X86_EFLAGS_IF; 1893 break; 1894 case X86EMUL_MODE_VM86: 1895 if (iopl < 3) 1896 return emulate_gp(ctxt, 0); 1897 change_mask |= X86_EFLAGS_IF; 1898 break; 1899 default: /* real mode */ 1900 change_mask |= (X86_EFLAGS_IOPL | X86_EFLAGS_IF); 1901 break; 1902 } 1903 1904 *(unsigned long *)dest = 1905 (ctxt->eflags & ~change_mask) | (val & change_mask); 1906 1907 return rc; 1908 } 1909 1910 static int em_popf(struct x86_emulate_ctxt *ctxt) 1911 { 1912 ctxt->dst.type = OP_REG; 1913 ctxt->dst.addr.reg = &ctxt->eflags; 1914 ctxt->dst.bytes = ctxt->op_bytes; 1915 return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes); 1916 } 1917 1918 static int em_enter(struct x86_emulate_ctxt *ctxt) 1919 { 1920 int rc; 1921 unsigned frame_size = ctxt->src.val; 1922 unsigned nesting_level = ctxt->src2.val & 31; 1923 ulong rbp; 1924 1925 if (nesting_level) 1926 return X86EMUL_UNHANDLEABLE; 1927 1928 rbp = reg_read(ctxt, VCPU_REGS_RBP); 1929 rc = push(ctxt, &rbp, stack_size(ctxt)); 1930 if (rc != X86EMUL_CONTINUE) 1931 return rc; 1932 assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP), 1933 stack_mask(ctxt)); 1934 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), 1935 reg_read(ctxt, VCPU_REGS_RSP) - frame_size, 1936 stack_mask(ctxt)); 1937 return X86EMUL_CONTINUE; 1938 } 1939 1940 static int em_leave(struct x86_emulate_ctxt *ctxt) 1941 { 1942 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP), 1943 stack_mask(ctxt)); 1944 return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes); 1945 } 1946 1947 static int em_push_sreg(struct x86_emulate_ctxt *ctxt) 1948 { 1949 int seg = ctxt->src2.val; 1950 1951 ctxt->src.val = get_segment_selector(ctxt, seg); 1952 if (ctxt->op_bytes == 4) { 1953 rsp_increment(ctxt, -2); 1954 ctxt->op_bytes = 2; 1955 } 1956 1957 return em_push(ctxt); 1958 } 1959 1960 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt) 1961 { 1962 int seg = ctxt->src2.val; 1963 unsigned long selector; 1964 int rc; 1965 1966 rc = emulate_pop(ctxt, &selector, 2); 1967 if (rc != X86EMUL_CONTINUE) 1968 return rc; 1969 1970 if (ctxt->modrm_reg == VCPU_SREG_SS) 1971 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; 1972 if (ctxt->op_bytes > 2) 1973 rsp_increment(ctxt, ctxt->op_bytes - 2); 1974 1975 rc = load_segment_descriptor(ctxt, (u16)selector, seg); 1976 return rc; 1977 } 1978 1979 static int em_pusha(struct x86_emulate_ctxt *ctxt) 1980 { 1981 unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP); 1982 int rc = X86EMUL_CONTINUE; 1983 int reg = VCPU_REGS_RAX; 1984 1985 while (reg <= VCPU_REGS_RDI) { 1986 (reg == VCPU_REGS_RSP) ? 1987 (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg)); 1988 1989 rc = em_push(ctxt); 1990 if (rc != X86EMUL_CONTINUE) 1991 return rc; 1992 1993 ++reg; 1994 } 1995 1996 return rc; 1997 } 1998 1999 static int em_pushf(struct x86_emulate_ctxt *ctxt) 2000 { 2001 ctxt->src.val = (unsigned long)ctxt->eflags & ~X86_EFLAGS_VM; 2002 return em_push(ctxt); 2003 } 2004 2005 static int em_popa(struct x86_emulate_ctxt *ctxt) 2006 { 2007 int rc = X86EMUL_CONTINUE; 2008 int reg = VCPU_REGS_RDI; 2009 u32 val; 2010 2011 while (reg >= VCPU_REGS_RAX) { 2012 if (reg == VCPU_REGS_RSP) { 2013 rsp_increment(ctxt, ctxt->op_bytes); 2014 --reg; 2015 } 2016 2017 rc = emulate_pop(ctxt, &val, ctxt->op_bytes); 2018 if (rc != X86EMUL_CONTINUE) 2019 break; 2020 assign_register(reg_rmw(ctxt, reg), val, ctxt->op_bytes); 2021 --reg; 2022 } 2023 return rc; 2024 } 2025 2026 static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) 2027 { 2028 const struct x86_emulate_ops *ops = ctxt->ops; 2029 int rc; 2030 struct desc_ptr dt; 2031 gva_t cs_addr; 2032 gva_t eip_addr; 2033 u16 cs, eip; 2034 2035 /* TODO: Add limit checks */ 2036 ctxt->src.val = ctxt->eflags; 2037 rc = em_push(ctxt); 2038 if (rc != X86EMUL_CONTINUE) 2039 return rc; 2040 2041 ctxt->eflags &= ~(X86_EFLAGS_IF | X86_EFLAGS_TF | X86_EFLAGS_AC); 2042 2043 ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS); 2044 rc = em_push(ctxt); 2045 if (rc != X86EMUL_CONTINUE) 2046 return rc; 2047 2048 ctxt->src.val = ctxt->_eip; 2049 rc = em_push(ctxt); 2050 if (rc != X86EMUL_CONTINUE) 2051 return rc; 2052 2053 ops->get_idt(ctxt, &dt); 2054 2055 eip_addr = dt.address + (irq << 2); 2056 cs_addr = dt.address + (irq << 2) + 2; 2057 2058 rc = linear_read_system(ctxt, cs_addr, &cs, 2); 2059 if (rc != X86EMUL_CONTINUE) 2060 return rc; 2061 2062 rc = linear_read_system(ctxt, eip_addr, &eip, 2); 2063 if (rc != X86EMUL_CONTINUE) 2064 return rc; 2065 2066 rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS); 2067 if (rc != X86EMUL_CONTINUE) 2068 return rc; 2069 2070 ctxt->_eip = eip; 2071 2072 return rc; 2073 } 2074 2075 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) 2076 { 2077 int rc; 2078 2079 invalidate_registers(ctxt); 2080 rc = __emulate_int_real(ctxt, irq); 2081 if (rc == X86EMUL_CONTINUE) 2082 writeback_registers(ctxt); 2083 return rc; 2084 } 2085 2086 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq) 2087 { 2088 switch(ctxt->mode) { 2089 case X86EMUL_MODE_REAL: 2090 return __emulate_int_real(ctxt, irq); 2091 case X86EMUL_MODE_VM86: 2092 case X86EMUL_MODE_PROT16: 2093 case X86EMUL_MODE_PROT32: 2094 case X86EMUL_MODE_PROT64: 2095 default: 2096 /* Protected mode interrupts unimplemented yet */ 2097 return X86EMUL_UNHANDLEABLE; 2098 } 2099 } 2100 2101 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt) 2102 { 2103 int rc = X86EMUL_CONTINUE; 2104 unsigned long temp_eip = 0; 2105 unsigned long temp_eflags = 0; 2106 unsigned long cs = 0; 2107 unsigned long mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | 2108 X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_TF | 2109 X86_EFLAGS_IF | X86_EFLAGS_DF | X86_EFLAGS_OF | 2110 X86_EFLAGS_IOPL | X86_EFLAGS_NT | X86_EFLAGS_RF | 2111 X86_EFLAGS_AC | X86_EFLAGS_ID | 2112 X86_EFLAGS_FIXED; 2113 unsigned long vm86_mask = X86_EFLAGS_VM | X86_EFLAGS_VIF | 2114 X86_EFLAGS_VIP; 2115 2116 /* TODO: Add stack limit check */ 2117 2118 rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes); 2119 2120 if (rc != X86EMUL_CONTINUE) 2121 return rc; 2122 2123 if (temp_eip & ~0xffff) 2124 return emulate_gp(ctxt, 0); 2125 2126 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); 2127 2128 if (rc != X86EMUL_CONTINUE) 2129 return rc; 2130 2131 rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes); 2132 2133 if (rc != X86EMUL_CONTINUE) 2134 return rc; 2135 2136 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS); 2137 2138 if (rc != X86EMUL_CONTINUE) 2139 return rc; 2140 2141 ctxt->_eip = temp_eip; 2142 2143 if (ctxt->op_bytes == 4) 2144 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask)); 2145 else if (ctxt->op_bytes == 2) { 2146 ctxt->eflags &= ~0xffff; 2147 ctxt->eflags |= temp_eflags; 2148 } 2149 2150 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */ 2151 ctxt->eflags |= X86_EFLAGS_FIXED; 2152 ctxt->ops->set_nmi_mask(ctxt, false); 2153 2154 return rc; 2155 } 2156 2157 static int em_iret(struct x86_emulate_ctxt *ctxt) 2158 { 2159 switch(ctxt->mode) { 2160 case X86EMUL_MODE_REAL: 2161 return emulate_iret_real(ctxt); 2162 case X86EMUL_MODE_VM86: 2163 case X86EMUL_MODE_PROT16: 2164 case X86EMUL_MODE_PROT32: 2165 case X86EMUL_MODE_PROT64: 2166 default: 2167 /* iret from protected mode unimplemented yet */ 2168 return X86EMUL_UNHANDLEABLE; 2169 } 2170 } 2171 2172 static int em_jmp_far(struct x86_emulate_ctxt *ctxt) 2173 { 2174 int rc; 2175 unsigned short sel; 2176 struct desc_struct new_desc; 2177 u8 cpl = ctxt->ops->cpl(ctxt); 2178 2179 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); 2180 2181 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, 2182 X86_TRANSFER_CALL_JMP, 2183 &new_desc); 2184 if (rc != X86EMUL_CONTINUE) 2185 return rc; 2186 2187 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc); 2188 /* Error handling is not implemented. */ 2189 if (rc != X86EMUL_CONTINUE) 2190 return X86EMUL_UNHANDLEABLE; 2191 2192 return rc; 2193 } 2194 2195 static int em_jmp_abs(struct x86_emulate_ctxt *ctxt) 2196 { 2197 return assign_eip_near(ctxt, ctxt->src.val); 2198 } 2199 2200 static int em_call_near_abs(struct x86_emulate_ctxt *ctxt) 2201 { 2202 int rc; 2203 long int old_eip; 2204 2205 old_eip = ctxt->_eip; 2206 rc = assign_eip_near(ctxt, ctxt->src.val); 2207 if (rc != X86EMUL_CONTINUE) 2208 return rc; 2209 ctxt->src.val = old_eip; 2210 rc = em_push(ctxt); 2211 return rc; 2212 } 2213 2214 static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt) 2215 { 2216 u64 old = ctxt->dst.orig_val64; 2217 2218 if (ctxt->dst.bytes == 16) 2219 return X86EMUL_UNHANDLEABLE; 2220 2221 if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) || 2222 ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) { 2223 *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0); 2224 *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32); 2225 ctxt->eflags &= ~X86_EFLAGS_ZF; 2226 } else { 2227 ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) | 2228 (u32) reg_read(ctxt, VCPU_REGS_RBX); 2229 2230 ctxt->eflags |= X86_EFLAGS_ZF; 2231 } 2232 return X86EMUL_CONTINUE; 2233 } 2234 2235 static int em_ret(struct x86_emulate_ctxt *ctxt) 2236 { 2237 int rc; 2238 unsigned long eip; 2239 2240 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); 2241 if (rc != X86EMUL_CONTINUE) 2242 return rc; 2243 2244 return assign_eip_near(ctxt, eip); 2245 } 2246 2247 static int em_ret_far(struct x86_emulate_ctxt *ctxt) 2248 { 2249 int rc; 2250 unsigned long eip, cs; 2251 int cpl = ctxt->ops->cpl(ctxt); 2252 struct desc_struct new_desc; 2253 2254 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); 2255 if (rc != X86EMUL_CONTINUE) 2256 return rc; 2257 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); 2258 if (rc != X86EMUL_CONTINUE) 2259 return rc; 2260 rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, cpl, 2261 X86_TRANSFER_RET, 2262 &new_desc); 2263 if (rc != X86EMUL_CONTINUE) 2264 return rc; 2265 rc = assign_eip_far(ctxt, eip, &new_desc); 2266 /* Error handling is not implemented. */ 2267 if (rc != X86EMUL_CONTINUE) 2268 return X86EMUL_UNHANDLEABLE; 2269 2270 return rc; 2271 } 2272 2273 static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt) 2274 { 2275 int rc; 2276 2277 rc = em_ret_far(ctxt); 2278 if (rc != X86EMUL_CONTINUE) 2279 return rc; 2280 rsp_increment(ctxt, ctxt->src.val); 2281 return X86EMUL_CONTINUE; 2282 } 2283 2284 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) 2285 { 2286 /* Save real source value, then compare EAX against destination. */ 2287 ctxt->dst.orig_val = ctxt->dst.val; 2288 ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX); 2289 ctxt->src.orig_val = ctxt->src.val; 2290 ctxt->src.val = ctxt->dst.orig_val; 2291 fastop(ctxt, em_cmp); 2292 2293 if (ctxt->eflags & X86_EFLAGS_ZF) { 2294 /* Success: write back to memory; no update of EAX */ 2295 ctxt->src.type = OP_NONE; 2296 ctxt->dst.val = ctxt->src.orig_val; 2297 } else { 2298 /* Failure: write the value we saw to EAX. */ 2299 ctxt->src.type = OP_REG; 2300 ctxt->src.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); 2301 ctxt->src.val = ctxt->dst.orig_val; 2302 /* Create write-cycle to dest by writing the same value */ 2303 ctxt->dst.val = ctxt->dst.orig_val; 2304 } 2305 return X86EMUL_CONTINUE; 2306 } 2307 2308 static int em_lseg(struct x86_emulate_ctxt *ctxt) 2309 { 2310 int seg = ctxt->src2.val; 2311 unsigned short sel; 2312 int rc; 2313 2314 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); 2315 2316 rc = load_segment_descriptor(ctxt, sel, seg); 2317 if (rc != X86EMUL_CONTINUE) 2318 return rc; 2319 2320 ctxt->dst.val = ctxt->src.val; 2321 return rc; 2322 } 2323 2324 static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt) 2325 { 2326 #ifdef CONFIG_X86_64 2327 return ctxt->ops->guest_has_long_mode(ctxt); 2328 #else 2329 return false; 2330 #endif 2331 } 2332 2333 static void rsm_set_desc_flags(struct desc_struct *desc, u32 flags) 2334 { 2335 desc->g = (flags >> 23) & 1; 2336 desc->d = (flags >> 22) & 1; 2337 desc->l = (flags >> 21) & 1; 2338 desc->avl = (flags >> 20) & 1; 2339 desc->p = (flags >> 15) & 1; 2340 desc->dpl = (flags >> 13) & 3; 2341 desc->s = (flags >> 12) & 1; 2342 desc->type = (flags >> 8) & 15; 2343 } 2344 2345 static int rsm_load_seg_32(struct x86_emulate_ctxt *ctxt, const char *smstate, 2346 int n) 2347 { 2348 struct desc_struct desc; 2349 int offset; 2350 u16 selector; 2351 2352 selector = GET_SMSTATE(u32, smstate, 0x7fa8 + n * 4); 2353 2354 if (n < 3) 2355 offset = 0x7f84 + n * 12; 2356 else 2357 offset = 0x7f2c + (n - 3) * 12; 2358 2359 set_desc_base(&desc, GET_SMSTATE(u32, smstate, offset + 8)); 2360 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, offset + 4)); 2361 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, offset)); 2362 ctxt->ops->set_segment(ctxt, selector, &desc, 0, n); 2363 return X86EMUL_CONTINUE; 2364 } 2365 2366 #ifdef CONFIG_X86_64 2367 static int rsm_load_seg_64(struct x86_emulate_ctxt *ctxt, const char *smstate, 2368 int n) 2369 { 2370 struct desc_struct desc; 2371 int offset; 2372 u16 selector; 2373 u32 base3; 2374 2375 offset = 0x7e00 + n * 16; 2376 2377 selector = GET_SMSTATE(u16, smstate, offset); 2378 rsm_set_desc_flags(&desc, GET_SMSTATE(u16, smstate, offset + 2) << 8); 2379 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, offset + 4)); 2380 set_desc_base(&desc, GET_SMSTATE(u32, smstate, offset + 8)); 2381 base3 = GET_SMSTATE(u32, smstate, offset + 12); 2382 2383 ctxt->ops->set_segment(ctxt, selector, &desc, base3, n); 2384 return X86EMUL_CONTINUE; 2385 } 2386 #endif 2387 2388 static int rsm_enter_protected_mode(struct x86_emulate_ctxt *ctxt, 2389 u64 cr0, u64 cr3, u64 cr4) 2390 { 2391 int bad; 2392 u64 pcid; 2393 2394 /* In order to later set CR4.PCIDE, CR3[11:0] must be zero. */ 2395 pcid = 0; 2396 if (cr4 & X86_CR4_PCIDE) { 2397 pcid = cr3 & 0xfff; 2398 cr3 &= ~0xfff; 2399 } 2400 2401 bad = ctxt->ops->set_cr(ctxt, 3, cr3); 2402 if (bad) 2403 return X86EMUL_UNHANDLEABLE; 2404 2405 /* 2406 * First enable PAE, long mode needs it before CR0.PG = 1 is set. 2407 * Then enable protected mode. However, PCID cannot be enabled 2408 * if EFER.LMA=0, so set it separately. 2409 */ 2410 bad = ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE); 2411 if (bad) 2412 return X86EMUL_UNHANDLEABLE; 2413 2414 bad = ctxt->ops->set_cr(ctxt, 0, cr0); 2415 if (bad) 2416 return X86EMUL_UNHANDLEABLE; 2417 2418 if (cr4 & X86_CR4_PCIDE) { 2419 bad = ctxt->ops->set_cr(ctxt, 4, cr4); 2420 if (bad) 2421 return X86EMUL_UNHANDLEABLE; 2422 if (pcid) { 2423 bad = ctxt->ops->set_cr(ctxt, 3, cr3 | pcid); 2424 if (bad) 2425 return X86EMUL_UNHANDLEABLE; 2426 } 2427 2428 } 2429 2430 return X86EMUL_CONTINUE; 2431 } 2432 2433 static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, 2434 const char *smstate) 2435 { 2436 struct desc_struct desc; 2437 struct desc_ptr dt; 2438 u16 selector; 2439 u32 val, cr0, cr3, cr4; 2440 int i; 2441 2442 cr0 = GET_SMSTATE(u32, smstate, 0x7ffc); 2443 cr3 = GET_SMSTATE(u32, smstate, 0x7ff8); 2444 ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7ff4) | X86_EFLAGS_FIXED; 2445 ctxt->_eip = GET_SMSTATE(u32, smstate, 0x7ff0); 2446 2447 for (i = 0; i < NR_EMULATOR_GPRS; i++) 2448 *reg_write(ctxt, i) = GET_SMSTATE(u32, smstate, 0x7fd0 + i * 4); 2449 2450 val = GET_SMSTATE(u32, smstate, 0x7fcc); 2451 2452 if (ctxt->ops->set_dr(ctxt, 6, val)) 2453 return X86EMUL_UNHANDLEABLE; 2454 2455 val = GET_SMSTATE(u32, smstate, 0x7fc8); 2456 2457 if (ctxt->ops->set_dr(ctxt, 7, val)) 2458 return X86EMUL_UNHANDLEABLE; 2459 2460 selector = GET_SMSTATE(u32, smstate, 0x7fc4); 2461 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7f64)); 2462 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7f60)); 2463 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7f5c)); 2464 ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_TR); 2465 2466 selector = GET_SMSTATE(u32, smstate, 0x7fc0); 2467 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7f80)); 2468 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7f7c)); 2469 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7f78)); 2470 ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_LDTR); 2471 2472 dt.address = GET_SMSTATE(u32, smstate, 0x7f74); 2473 dt.size = GET_SMSTATE(u32, smstate, 0x7f70); 2474 ctxt->ops->set_gdt(ctxt, &dt); 2475 2476 dt.address = GET_SMSTATE(u32, smstate, 0x7f58); 2477 dt.size = GET_SMSTATE(u32, smstate, 0x7f54); 2478 ctxt->ops->set_idt(ctxt, &dt); 2479 2480 for (i = 0; i < 6; i++) { 2481 int r = rsm_load_seg_32(ctxt, smstate, i); 2482 if (r != X86EMUL_CONTINUE) 2483 return r; 2484 } 2485 2486 cr4 = GET_SMSTATE(u32, smstate, 0x7f14); 2487 2488 ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smstate, 0x7ef8)); 2489 2490 return rsm_enter_protected_mode(ctxt, cr0, cr3, cr4); 2491 } 2492 2493 #ifdef CONFIG_X86_64 2494 static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, 2495 const char *smstate) 2496 { 2497 struct desc_struct desc; 2498 struct desc_ptr dt; 2499 u64 val, cr0, cr3, cr4; 2500 u32 base3; 2501 u16 selector; 2502 int i, r; 2503 2504 for (i = 0; i < NR_EMULATOR_GPRS; i++) 2505 *reg_write(ctxt, i) = GET_SMSTATE(u64, smstate, 0x7ff8 - i * 8); 2506 2507 ctxt->_eip = GET_SMSTATE(u64, smstate, 0x7f78); 2508 ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7f70) | X86_EFLAGS_FIXED; 2509 2510 val = GET_SMSTATE(u64, smstate, 0x7f68); 2511 2512 if (ctxt->ops->set_dr(ctxt, 6, val)) 2513 return X86EMUL_UNHANDLEABLE; 2514 2515 val = GET_SMSTATE(u64, smstate, 0x7f60); 2516 2517 if (ctxt->ops->set_dr(ctxt, 7, val)) 2518 return X86EMUL_UNHANDLEABLE; 2519 2520 cr0 = GET_SMSTATE(u64, smstate, 0x7f58); 2521 cr3 = GET_SMSTATE(u64, smstate, 0x7f50); 2522 cr4 = GET_SMSTATE(u64, smstate, 0x7f48); 2523 ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smstate, 0x7f00)); 2524 val = GET_SMSTATE(u64, smstate, 0x7ed0); 2525 2526 if (ctxt->ops->set_msr(ctxt, MSR_EFER, val & ~EFER_LMA)) 2527 return X86EMUL_UNHANDLEABLE; 2528 2529 selector = GET_SMSTATE(u32, smstate, 0x7e90); 2530 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7e92) << 8); 2531 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7e94)); 2532 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7e98)); 2533 base3 = GET_SMSTATE(u32, smstate, 0x7e9c); 2534 ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_TR); 2535 2536 dt.size = GET_SMSTATE(u32, smstate, 0x7e84); 2537 dt.address = GET_SMSTATE(u64, smstate, 0x7e88); 2538 ctxt->ops->set_idt(ctxt, &dt); 2539 2540 selector = GET_SMSTATE(u32, smstate, 0x7e70); 2541 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7e72) << 8); 2542 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7e74)); 2543 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7e78)); 2544 base3 = GET_SMSTATE(u32, smstate, 0x7e7c); 2545 ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_LDTR); 2546 2547 dt.size = GET_SMSTATE(u32, smstate, 0x7e64); 2548 dt.address = GET_SMSTATE(u64, smstate, 0x7e68); 2549 ctxt->ops->set_gdt(ctxt, &dt); 2550 2551 r = rsm_enter_protected_mode(ctxt, cr0, cr3, cr4); 2552 if (r != X86EMUL_CONTINUE) 2553 return r; 2554 2555 for (i = 0; i < 6; i++) { 2556 r = rsm_load_seg_64(ctxt, smstate, i); 2557 if (r != X86EMUL_CONTINUE) 2558 return r; 2559 } 2560 2561 return X86EMUL_CONTINUE; 2562 } 2563 #endif 2564 2565 static int em_rsm(struct x86_emulate_ctxt *ctxt) 2566 { 2567 unsigned long cr0, cr4, efer; 2568 char buf[512]; 2569 u64 smbase; 2570 int ret; 2571 2572 if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_MASK) == 0) 2573 return emulate_ud(ctxt); 2574 2575 smbase = ctxt->ops->get_smbase(ctxt); 2576 2577 ret = ctxt->ops->read_phys(ctxt, smbase + 0xfe00, buf, sizeof(buf)); 2578 if (ret != X86EMUL_CONTINUE) 2579 return X86EMUL_UNHANDLEABLE; 2580 2581 if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0) 2582 ctxt->ops->set_nmi_mask(ctxt, false); 2583 2584 ctxt->ops->exiting_smm(ctxt); 2585 2586 /* 2587 * Get back to real mode, to prepare a safe state in which to load 2588 * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU 2589 * supports long mode. 2590 */ 2591 if (emulator_has_longmode(ctxt)) { 2592 struct desc_struct cs_desc; 2593 2594 /* Zero CR4.PCIDE before CR0.PG. */ 2595 cr4 = ctxt->ops->get_cr(ctxt, 4); 2596 if (cr4 & X86_CR4_PCIDE) 2597 ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE); 2598 2599 /* A 32-bit code segment is required to clear EFER.LMA. */ 2600 memset(&cs_desc, 0, sizeof(cs_desc)); 2601 cs_desc.type = 0xb; 2602 cs_desc.s = cs_desc.g = cs_desc.p = 1; 2603 ctxt->ops->set_segment(ctxt, 0, &cs_desc, 0, VCPU_SREG_CS); 2604 } 2605 2606 /* For the 64-bit case, this will clear EFER.LMA. */ 2607 cr0 = ctxt->ops->get_cr(ctxt, 0); 2608 if (cr0 & X86_CR0_PE) 2609 ctxt->ops->set_cr(ctxt, 0, cr0 & ~(X86_CR0_PG | X86_CR0_PE)); 2610 2611 if (emulator_has_longmode(ctxt)) { 2612 /* Clear CR4.PAE before clearing EFER.LME. */ 2613 cr4 = ctxt->ops->get_cr(ctxt, 4); 2614 if (cr4 & X86_CR4_PAE) 2615 ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PAE); 2616 2617 /* And finally go back to 32-bit mode. */ 2618 efer = 0; 2619 ctxt->ops->set_msr(ctxt, MSR_EFER, efer); 2620 } 2621 2622 /* 2623 * Give leave_smm() a chance to make ISA-specific changes to the vCPU 2624 * state (e.g. enter guest mode) before loading state from the SMM 2625 * state-save area. 2626 */ 2627 if (ctxt->ops->leave_smm(ctxt, buf)) 2628 goto emulate_shutdown; 2629 2630 #ifdef CONFIG_X86_64 2631 if (emulator_has_longmode(ctxt)) 2632 ret = rsm_load_state_64(ctxt, buf); 2633 else 2634 #endif 2635 ret = rsm_load_state_32(ctxt, buf); 2636 2637 if (ret != X86EMUL_CONTINUE) 2638 goto emulate_shutdown; 2639 2640 /* 2641 * Note, the ctxt->ops callbacks are responsible for handling side 2642 * effects when writing MSRs and CRs, e.g. MMU context resets, CPUID 2643 * runtime updates, etc... If that changes, e.g. this flow is moved 2644 * out of the emulator to make it look more like enter_smm(), then 2645 * those side effects need to be explicitly handled for both success 2646 * and shutdown. 2647 */ 2648 return X86EMUL_CONTINUE; 2649 2650 emulate_shutdown: 2651 ctxt->ops->triple_fault(ctxt); 2652 return X86EMUL_CONTINUE; 2653 } 2654 2655 static void 2656 setup_syscalls_segments(struct desc_struct *cs, struct desc_struct *ss) 2657 { 2658 cs->l = 0; /* will be adjusted later */ 2659 set_desc_base(cs, 0); /* flat segment */ 2660 cs->g = 1; /* 4kb granularity */ 2661 set_desc_limit(cs, 0xfffff); /* 4GB limit */ 2662 cs->type = 0x0b; /* Read, Execute, Accessed */ 2663 cs->s = 1; 2664 cs->dpl = 0; /* will be adjusted later */ 2665 cs->p = 1; 2666 cs->d = 1; 2667 cs->avl = 0; 2668 2669 set_desc_base(ss, 0); /* flat segment */ 2670 set_desc_limit(ss, 0xfffff); /* 4GB limit */ 2671 ss->g = 1; /* 4kb granularity */ 2672 ss->s = 1; 2673 ss->type = 0x03; /* Read/Write, Accessed */ 2674 ss->d = 1; /* 32bit stack segment */ 2675 ss->dpl = 0; 2676 ss->p = 1; 2677 ss->l = 0; 2678 ss->avl = 0; 2679 } 2680 2681 static bool vendor_intel(struct x86_emulate_ctxt *ctxt) 2682 { 2683 u32 eax, ebx, ecx, edx; 2684 2685 eax = ecx = 0; 2686 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, true); 2687 return is_guest_vendor_intel(ebx, ecx, edx); 2688 } 2689 2690 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt) 2691 { 2692 const struct x86_emulate_ops *ops = ctxt->ops; 2693 u32 eax, ebx, ecx, edx; 2694 2695 /* 2696 * syscall should always be enabled in longmode - so only become 2697 * vendor specific (cpuid) if other modes are active... 2698 */ 2699 if (ctxt->mode == X86EMUL_MODE_PROT64) 2700 return true; 2701 2702 eax = 0x00000000; 2703 ecx = 0x00000000; 2704 ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, true); 2705 /* 2706 * remark: Intel CPUs only support "syscall" in 64bit longmode. Also a 2707 * 64bit guest with a 32bit compat-app running will #UD !! While this 2708 * behaviour can be fixed (by emulating) into AMD response - CPUs of 2709 * AMD can't behave like Intel. 2710 */ 2711 if (is_guest_vendor_intel(ebx, ecx, edx)) 2712 return false; 2713 2714 if (is_guest_vendor_amd(ebx, ecx, edx) || 2715 is_guest_vendor_hygon(ebx, ecx, edx)) 2716 return true; 2717 2718 /* 2719 * default: (not Intel, not AMD, not Hygon), apply Intel's 2720 * stricter rules... 2721 */ 2722 return false; 2723 } 2724 2725 static int em_syscall(struct x86_emulate_ctxt *ctxt) 2726 { 2727 const struct x86_emulate_ops *ops = ctxt->ops; 2728 struct desc_struct cs, ss; 2729 u64 msr_data; 2730 u16 cs_sel, ss_sel; 2731 u64 efer = 0; 2732 2733 /* syscall is not available in real mode */ 2734 if (ctxt->mode == X86EMUL_MODE_REAL || 2735 ctxt->mode == X86EMUL_MODE_VM86) 2736 return emulate_ud(ctxt); 2737 2738 if (!(em_syscall_is_enabled(ctxt))) 2739 return emulate_ud(ctxt); 2740 2741 ops->get_msr(ctxt, MSR_EFER, &efer); 2742 if (!(efer & EFER_SCE)) 2743 return emulate_ud(ctxt); 2744 2745 setup_syscalls_segments(&cs, &ss); 2746 ops->get_msr(ctxt, MSR_STAR, &msr_data); 2747 msr_data >>= 32; 2748 cs_sel = (u16)(msr_data & 0xfffc); 2749 ss_sel = (u16)(msr_data + 8); 2750 2751 if (efer & EFER_LMA) { 2752 cs.d = 0; 2753 cs.l = 1; 2754 } 2755 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2756 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2757 2758 *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip; 2759 if (efer & EFER_LMA) { 2760 #ifdef CONFIG_X86_64 2761 *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags; 2762 2763 ops->get_msr(ctxt, 2764 ctxt->mode == X86EMUL_MODE_PROT64 ? 2765 MSR_LSTAR : MSR_CSTAR, &msr_data); 2766 ctxt->_eip = msr_data; 2767 2768 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data); 2769 ctxt->eflags &= ~msr_data; 2770 ctxt->eflags |= X86_EFLAGS_FIXED; 2771 #endif 2772 } else { 2773 /* legacy mode */ 2774 ops->get_msr(ctxt, MSR_STAR, &msr_data); 2775 ctxt->_eip = (u32)msr_data; 2776 2777 ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); 2778 } 2779 2780 ctxt->tf = (ctxt->eflags & X86_EFLAGS_TF) != 0; 2781 return X86EMUL_CONTINUE; 2782 } 2783 2784 static int em_sysenter(struct x86_emulate_ctxt *ctxt) 2785 { 2786 const struct x86_emulate_ops *ops = ctxt->ops; 2787 struct desc_struct cs, ss; 2788 u64 msr_data; 2789 u16 cs_sel, ss_sel; 2790 u64 efer = 0; 2791 2792 ops->get_msr(ctxt, MSR_EFER, &efer); 2793 /* inject #GP if in real mode */ 2794 if (ctxt->mode == X86EMUL_MODE_REAL) 2795 return emulate_gp(ctxt, 0); 2796 2797 /* 2798 * Not recognized on AMD in compat mode (but is recognized in legacy 2799 * mode). 2800 */ 2801 if ((ctxt->mode != X86EMUL_MODE_PROT64) && (efer & EFER_LMA) 2802 && !vendor_intel(ctxt)) 2803 return emulate_ud(ctxt); 2804 2805 /* sysenter/sysexit have not been tested in 64bit mode. */ 2806 if (ctxt->mode == X86EMUL_MODE_PROT64) 2807 return X86EMUL_UNHANDLEABLE; 2808 2809 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); 2810 if ((msr_data & 0xfffc) == 0x0) 2811 return emulate_gp(ctxt, 0); 2812 2813 setup_syscalls_segments(&cs, &ss); 2814 ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); 2815 cs_sel = (u16)msr_data & ~SEGMENT_RPL_MASK; 2816 ss_sel = cs_sel + 8; 2817 if (efer & EFER_LMA) { 2818 cs.d = 0; 2819 cs.l = 1; 2820 } 2821 2822 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2823 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2824 2825 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data); 2826 ctxt->_eip = (efer & EFER_LMA) ? msr_data : (u32)msr_data; 2827 2828 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data); 2829 *reg_write(ctxt, VCPU_REGS_RSP) = (efer & EFER_LMA) ? msr_data : 2830 (u32)msr_data; 2831 if (efer & EFER_LMA) 2832 ctxt->mode = X86EMUL_MODE_PROT64; 2833 2834 return X86EMUL_CONTINUE; 2835 } 2836 2837 static int em_sysexit(struct x86_emulate_ctxt *ctxt) 2838 { 2839 const struct x86_emulate_ops *ops = ctxt->ops; 2840 struct desc_struct cs, ss; 2841 u64 msr_data, rcx, rdx; 2842 int usermode; 2843 u16 cs_sel = 0, ss_sel = 0; 2844 2845 /* inject #GP if in real mode or Virtual 8086 mode */ 2846 if (ctxt->mode == X86EMUL_MODE_REAL || 2847 ctxt->mode == X86EMUL_MODE_VM86) 2848 return emulate_gp(ctxt, 0); 2849 2850 setup_syscalls_segments(&cs, &ss); 2851 2852 if ((ctxt->rex_prefix & 0x8) != 0x0) 2853 usermode = X86EMUL_MODE_PROT64; 2854 else 2855 usermode = X86EMUL_MODE_PROT32; 2856 2857 rcx = reg_read(ctxt, VCPU_REGS_RCX); 2858 rdx = reg_read(ctxt, VCPU_REGS_RDX); 2859 2860 cs.dpl = 3; 2861 ss.dpl = 3; 2862 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); 2863 switch (usermode) { 2864 case X86EMUL_MODE_PROT32: 2865 cs_sel = (u16)(msr_data + 16); 2866 if ((msr_data & 0xfffc) == 0x0) 2867 return emulate_gp(ctxt, 0); 2868 ss_sel = (u16)(msr_data + 24); 2869 rcx = (u32)rcx; 2870 rdx = (u32)rdx; 2871 break; 2872 case X86EMUL_MODE_PROT64: 2873 cs_sel = (u16)(msr_data + 32); 2874 if (msr_data == 0x0) 2875 return emulate_gp(ctxt, 0); 2876 ss_sel = cs_sel + 8; 2877 cs.d = 0; 2878 cs.l = 1; 2879 if (emul_is_noncanonical_address(rcx, ctxt) || 2880 emul_is_noncanonical_address(rdx, ctxt)) 2881 return emulate_gp(ctxt, 0); 2882 break; 2883 } 2884 cs_sel |= SEGMENT_RPL_MASK; 2885 ss_sel |= SEGMENT_RPL_MASK; 2886 2887 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2888 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2889 2890 ctxt->_eip = rdx; 2891 *reg_write(ctxt, VCPU_REGS_RSP) = rcx; 2892 2893 return X86EMUL_CONTINUE; 2894 } 2895 2896 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt) 2897 { 2898 int iopl; 2899 if (ctxt->mode == X86EMUL_MODE_REAL) 2900 return false; 2901 if (ctxt->mode == X86EMUL_MODE_VM86) 2902 return true; 2903 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT; 2904 return ctxt->ops->cpl(ctxt) > iopl; 2905 } 2906 2907 #define VMWARE_PORT_VMPORT (0x5658) 2908 #define VMWARE_PORT_VMRPC (0x5659) 2909 2910 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, 2911 u16 port, u16 len) 2912 { 2913 const struct x86_emulate_ops *ops = ctxt->ops; 2914 struct desc_struct tr_seg; 2915 u32 base3; 2916 int r; 2917 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7; 2918 unsigned mask = (1 << len) - 1; 2919 unsigned long base; 2920 2921 /* 2922 * VMware allows access to these ports even if denied 2923 * by TSS I/O permission bitmap. Mimic behavior. 2924 */ 2925 if (enable_vmware_backdoor && 2926 ((port == VMWARE_PORT_VMPORT) || (port == VMWARE_PORT_VMRPC))) 2927 return true; 2928 2929 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR); 2930 if (!tr_seg.p) 2931 return false; 2932 if (desc_limit_scaled(&tr_seg) < 103) 2933 return false; 2934 base = get_desc_base(&tr_seg); 2935 #ifdef CONFIG_X86_64 2936 base |= ((u64)base3) << 32; 2937 #endif 2938 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL, true); 2939 if (r != X86EMUL_CONTINUE) 2940 return false; 2941 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg)) 2942 return false; 2943 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL, true); 2944 if (r != X86EMUL_CONTINUE) 2945 return false; 2946 if ((perm >> bit_idx) & mask) 2947 return false; 2948 return true; 2949 } 2950 2951 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, 2952 u16 port, u16 len) 2953 { 2954 if (ctxt->perm_ok) 2955 return true; 2956 2957 if (emulator_bad_iopl(ctxt)) 2958 if (!emulator_io_port_access_allowed(ctxt, port, len)) 2959 return false; 2960 2961 ctxt->perm_ok = true; 2962 2963 return true; 2964 } 2965 2966 static void string_registers_quirk(struct x86_emulate_ctxt *ctxt) 2967 { 2968 /* 2969 * Intel CPUs mask the counter and pointers in quite strange 2970 * manner when ECX is zero due to REP-string optimizations. 2971 */ 2972 #ifdef CONFIG_X86_64 2973 if (ctxt->ad_bytes != 4 || !vendor_intel(ctxt)) 2974 return; 2975 2976 *reg_write(ctxt, VCPU_REGS_RCX) = 0; 2977 2978 switch (ctxt->b) { 2979 case 0xa4: /* movsb */ 2980 case 0xa5: /* movsd/w */ 2981 *reg_rmw(ctxt, VCPU_REGS_RSI) &= (u32)-1; 2982 fallthrough; 2983 case 0xaa: /* stosb */ 2984 case 0xab: /* stosd/w */ 2985 *reg_rmw(ctxt, VCPU_REGS_RDI) &= (u32)-1; 2986 } 2987 #endif 2988 } 2989 2990 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, 2991 struct tss_segment_16 *tss) 2992 { 2993 tss->ip = ctxt->_eip; 2994 tss->flag = ctxt->eflags; 2995 tss->ax = reg_read(ctxt, VCPU_REGS_RAX); 2996 tss->cx = reg_read(ctxt, VCPU_REGS_RCX); 2997 tss->dx = reg_read(ctxt, VCPU_REGS_RDX); 2998 tss->bx = reg_read(ctxt, VCPU_REGS_RBX); 2999 tss->sp = reg_read(ctxt, VCPU_REGS_RSP); 3000 tss->bp = reg_read(ctxt, VCPU_REGS_RBP); 3001 tss->si = reg_read(ctxt, VCPU_REGS_RSI); 3002 tss->di = reg_read(ctxt, VCPU_REGS_RDI); 3003 3004 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); 3005 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); 3006 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); 3007 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); 3008 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR); 3009 } 3010 3011 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, 3012 struct tss_segment_16 *tss) 3013 { 3014 int ret; 3015 u8 cpl; 3016 3017 ctxt->_eip = tss->ip; 3018 ctxt->eflags = tss->flag | 2; 3019 *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax; 3020 *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx; 3021 *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx; 3022 *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx; 3023 *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp; 3024 *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp; 3025 *reg_write(ctxt, VCPU_REGS_RSI) = tss->si; 3026 *reg_write(ctxt, VCPU_REGS_RDI) = tss->di; 3027 3028 /* 3029 * SDM says that segment selectors are loaded before segment 3030 * descriptors 3031 */ 3032 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); 3033 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); 3034 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); 3035 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); 3036 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); 3037 3038 cpl = tss->cs & 3; 3039 3040 /* 3041 * Now load segment descriptors. If fault happens at this stage 3042 * it is handled in a context of new task 3043 */ 3044 ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl, 3045 X86_TRANSFER_TASK_SWITCH, NULL); 3046 if (ret != X86EMUL_CONTINUE) 3047 return ret; 3048 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, 3049 X86_TRANSFER_TASK_SWITCH, NULL); 3050 if (ret != X86EMUL_CONTINUE) 3051 return ret; 3052 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, 3053 X86_TRANSFER_TASK_SWITCH, NULL); 3054 if (ret != X86EMUL_CONTINUE) 3055 return ret; 3056 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, 3057 X86_TRANSFER_TASK_SWITCH, NULL); 3058 if (ret != X86EMUL_CONTINUE) 3059 return ret; 3060 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, 3061 X86_TRANSFER_TASK_SWITCH, NULL); 3062 if (ret != X86EMUL_CONTINUE) 3063 return ret; 3064 3065 return X86EMUL_CONTINUE; 3066 } 3067 3068 static int task_switch_16(struct x86_emulate_ctxt *ctxt, u16 old_tss_sel, 3069 ulong old_tss_base, struct desc_struct *new_desc) 3070 { 3071 struct tss_segment_16 tss_seg; 3072 int ret; 3073 u32 new_tss_base = get_desc_base(new_desc); 3074 3075 ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof(tss_seg)); 3076 if (ret != X86EMUL_CONTINUE) 3077 return ret; 3078 3079 save_state_to_tss16(ctxt, &tss_seg); 3080 3081 ret = linear_write_system(ctxt, old_tss_base, &tss_seg, sizeof(tss_seg)); 3082 if (ret != X86EMUL_CONTINUE) 3083 return ret; 3084 3085 ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof(tss_seg)); 3086 if (ret != X86EMUL_CONTINUE) 3087 return ret; 3088 3089 if (old_tss_sel != 0xffff) { 3090 tss_seg.prev_task_link = old_tss_sel; 3091 3092 ret = linear_write_system(ctxt, new_tss_base, 3093 &tss_seg.prev_task_link, 3094 sizeof(tss_seg.prev_task_link)); 3095 if (ret != X86EMUL_CONTINUE) 3096 return ret; 3097 } 3098 3099 return load_state_from_tss16(ctxt, &tss_seg); 3100 } 3101 3102 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, 3103 struct tss_segment_32 *tss) 3104 { 3105 /* CR3 and ldt selector are not saved intentionally */ 3106 tss->eip = ctxt->_eip; 3107 tss->eflags = ctxt->eflags; 3108 tss->eax = reg_read(ctxt, VCPU_REGS_RAX); 3109 tss->ecx = reg_read(ctxt, VCPU_REGS_RCX); 3110 tss->edx = reg_read(ctxt, VCPU_REGS_RDX); 3111 tss->ebx = reg_read(ctxt, VCPU_REGS_RBX); 3112 tss->esp = reg_read(ctxt, VCPU_REGS_RSP); 3113 tss->ebp = reg_read(ctxt, VCPU_REGS_RBP); 3114 tss->esi = reg_read(ctxt, VCPU_REGS_RSI); 3115 tss->edi = reg_read(ctxt, VCPU_REGS_RDI); 3116 3117 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); 3118 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); 3119 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); 3120 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); 3121 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); 3122 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); 3123 } 3124 3125 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, 3126 struct tss_segment_32 *tss) 3127 { 3128 int ret; 3129 u8 cpl; 3130 3131 if (ctxt->ops->set_cr(ctxt, 3, tss->cr3)) 3132 return emulate_gp(ctxt, 0); 3133 ctxt->_eip = tss->eip; 3134 ctxt->eflags = tss->eflags | 2; 3135 3136 /* General purpose registers */ 3137 *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax; 3138 *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx; 3139 *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx; 3140 *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx; 3141 *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp; 3142 *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp; 3143 *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi; 3144 *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi; 3145 3146 /* 3147 * SDM says that segment selectors are loaded before segment 3148 * descriptors. This is important because CPL checks will 3149 * use CS.RPL. 3150 */ 3151 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); 3152 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); 3153 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); 3154 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); 3155 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); 3156 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); 3157 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); 3158 3159 /* 3160 * If we're switching between Protected Mode and VM86, we need to make 3161 * sure to update the mode before loading the segment descriptors so 3162 * that the selectors are interpreted correctly. 3163 */ 3164 if (ctxt->eflags & X86_EFLAGS_VM) { 3165 ctxt->mode = X86EMUL_MODE_VM86; 3166 cpl = 3; 3167 } else { 3168 ctxt->mode = X86EMUL_MODE_PROT32; 3169 cpl = tss->cs & 3; 3170 } 3171 3172 /* 3173 * Now load segment descriptors. If fault happens at this stage 3174 * it is handled in a context of new task 3175 */ 3176 ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR, 3177 cpl, X86_TRANSFER_TASK_SWITCH, NULL); 3178 if (ret != X86EMUL_CONTINUE) 3179 return ret; 3180 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, 3181 X86_TRANSFER_TASK_SWITCH, NULL); 3182 if (ret != X86EMUL_CONTINUE) 3183 return ret; 3184 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, 3185 X86_TRANSFER_TASK_SWITCH, NULL); 3186 if (ret != X86EMUL_CONTINUE) 3187 return ret; 3188 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, 3189 X86_TRANSFER_TASK_SWITCH, NULL); 3190 if (ret != X86EMUL_CONTINUE) 3191 return ret; 3192 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, 3193 X86_TRANSFER_TASK_SWITCH, NULL); 3194 if (ret != X86EMUL_CONTINUE) 3195 return ret; 3196 ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl, 3197 X86_TRANSFER_TASK_SWITCH, NULL); 3198 if (ret != X86EMUL_CONTINUE) 3199 return ret; 3200 ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl, 3201 X86_TRANSFER_TASK_SWITCH, NULL); 3202 3203 return ret; 3204 } 3205 3206 static int task_switch_32(struct x86_emulate_ctxt *ctxt, u16 old_tss_sel, 3207 ulong old_tss_base, struct desc_struct *new_desc) 3208 { 3209 struct tss_segment_32 tss_seg; 3210 int ret; 3211 u32 new_tss_base = get_desc_base(new_desc); 3212 u32 eip_offset = offsetof(struct tss_segment_32, eip); 3213 u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector); 3214 3215 ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof(tss_seg)); 3216 if (ret != X86EMUL_CONTINUE) 3217 return ret; 3218 3219 save_state_to_tss32(ctxt, &tss_seg); 3220 3221 /* Only GP registers and segment selectors are saved */ 3222 ret = linear_write_system(ctxt, old_tss_base + eip_offset, &tss_seg.eip, 3223 ldt_sel_offset - eip_offset); 3224 if (ret != X86EMUL_CONTINUE) 3225 return ret; 3226 3227 ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof(tss_seg)); 3228 if (ret != X86EMUL_CONTINUE) 3229 return ret; 3230 3231 if (old_tss_sel != 0xffff) { 3232 tss_seg.prev_task_link = old_tss_sel; 3233 3234 ret = linear_write_system(ctxt, new_tss_base, 3235 &tss_seg.prev_task_link, 3236 sizeof(tss_seg.prev_task_link)); 3237 if (ret != X86EMUL_CONTINUE) 3238 return ret; 3239 } 3240 3241 return load_state_from_tss32(ctxt, &tss_seg); 3242 } 3243 3244 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, 3245 u16 tss_selector, int idt_index, int reason, 3246 bool has_error_code, u32 error_code) 3247 { 3248 const struct x86_emulate_ops *ops = ctxt->ops; 3249 struct desc_struct curr_tss_desc, next_tss_desc; 3250 int ret; 3251 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR); 3252 ulong old_tss_base = 3253 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); 3254 u32 desc_limit; 3255 ulong desc_addr, dr7; 3256 3257 /* FIXME: old_tss_base == ~0 ? */ 3258 3259 ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr); 3260 if (ret != X86EMUL_CONTINUE) 3261 return ret; 3262 ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr); 3263 if (ret != X86EMUL_CONTINUE) 3264 return ret; 3265 3266 /* FIXME: check that next_tss_desc is tss */ 3267 3268 /* 3269 * Check privileges. The three cases are task switch caused by... 3270 * 3271 * 1. jmp/call/int to task gate: Check against DPL of the task gate 3272 * 2. Exception/IRQ/iret: No check is performed 3273 * 3. jmp/call to TSS/task-gate: No check is performed since the 3274 * hardware checks it before exiting. 3275 */ 3276 if (reason == TASK_SWITCH_GATE) { 3277 if (idt_index != -1) { 3278 /* Software interrupts */ 3279 struct desc_struct task_gate_desc; 3280 int dpl; 3281 3282 ret = read_interrupt_descriptor(ctxt, idt_index, 3283 &task_gate_desc); 3284 if (ret != X86EMUL_CONTINUE) 3285 return ret; 3286 3287 dpl = task_gate_desc.dpl; 3288 if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl) 3289 return emulate_gp(ctxt, (idt_index << 3) | 0x2); 3290 } 3291 } 3292 3293 desc_limit = desc_limit_scaled(&next_tss_desc); 3294 if (!next_tss_desc.p || 3295 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || 3296 desc_limit < 0x2b)) { 3297 return emulate_ts(ctxt, tss_selector & 0xfffc); 3298 } 3299 3300 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { 3301 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ 3302 write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc); 3303 } 3304 3305 if (reason == TASK_SWITCH_IRET) 3306 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; 3307 3308 /* set back link to prev task only if NT bit is set in eflags 3309 note that old_tss_sel is not used after this point */ 3310 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) 3311 old_tss_sel = 0xffff; 3312 3313 if (next_tss_desc.type & 8) 3314 ret = task_switch_32(ctxt, old_tss_sel, old_tss_base, &next_tss_desc); 3315 else 3316 ret = task_switch_16(ctxt, old_tss_sel, 3317 old_tss_base, &next_tss_desc); 3318 if (ret != X86EMUL_CONTINUE) 3319 return ret; 3320 3321 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) 3322 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; 3323 3324 if (reason != TASK_SWITCH_IRET) { 3325 next_tss_desc.type |= (1 << 1); /* set busy flag */ 3326 write_segment_descriptor(ctxt, tss_selector, &next_tss_desc); 3327 } 3328 3329 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS); 3330 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR); 3331 3332 if (has_error_code) { 3333 ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; 3334 ctxt->lock_prefix = 0; 3335 ctxt->src.val = (unsigned long) error_code; 3336 ret = em_push(ctxt); 3337 } 3338 3339 ops->get_dr(ctxt, 7, &dr7); 3340 ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN)); 3341 3342 return ret; 3343 } 3344 3345 int emulator_task_switch(struct x86_emulate_ctxt *ctxt, 3346 u16 tss_selector, int idt_index, int reason, 3347 bool has_error_code, u32 error_code) 3348 { 3349 int rc; 3350 3351 invalidate_registers(ctxt); 3352 ctxt->_eip = ctxt->eip; 3353 ctxt->dst.type = OP_NONE; 3354 3355 rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason, 3356 has_error_code, error_code); 3357 3358 if (rc == X86EMUL_CONTINUE) { 3359 ctxt->eip = ctxt->_eip; 3360 writeback_registers(ctxt); 3361 } 3362 3363 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 3364 } 3365 3366 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg, 3367 struct operand *op) 3368 { 3369 int df = (ctxt->eflags & X86_EFLAGS_DF) ? -op->count : op->count; 3370 3371 register_address_increment(ctxt, reg, df * op->bytes); 3372 op->addr.mem.ea = register_address(ctxt, reg); 3373 } 3374 3375 static int em_das(struct x86_emulate_ctxt *ctxt) 3376 { 3377 u8 al, old_al; 3378 bool af, cf, old_cf; 3379 3380 cf = ctxt->eflags & X86_EFLAGS_CF; 3381 al = ctxt->dst.val; 3382 3383 old_al = al; 3384 old_cf = cf; 3385 cf = false; 3386 af = ctxt->eflags & X86_EFLAGS_AF; 3387 if ((al & 0x0f) > 9 || af) { 3388 al -= 6; 3389 cf = old_cf | (al >= 250); 3390 af = true; 3391 } else { 3392 af = false; 3393 } 3394 if (old_al > 0x99 || old_cf) { 3395 al -= 0x60; 3396 cf = true; 3397 } 3398 3399 ctxt->dst.val = al; 3400 /* Set PF, ZF, SF */ 3401 ctxt->src.type = OP_IMM; 3402 ctxt->src.val = 0; 3403 ctxt->src.bytes = 1; 3404 fastop(ctxt, em_or); 3405 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF); 3406 if (cf) 3407 ctxt->eflags |= X86_EFLAGS_CF; 3408 if (af) 3409 ctxt->eflags |= X86_EFLAGS_AF; 3410 return X86EMUL_CONTINUE; 3411 } 3412 3413 static int em_aam(struct x86_emulate_ctxt *ctxt) 3414 { 3415 u8 al, ah; 3416 3417 if (ctxt->src.val == 0) 3418 return emulate_de(ctxt); 3419 3420 al = ctxt->dst.val & 0xff; 3421 ah = al / ctxt->src.val; 3422 al %= ctxt->src.val; 3423 3424 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8); 3425 3426 /* Set PF, ZF, SF */ 3427 ctxt->src.type = OP_IMM; 3428 ctxt->src.val = 0; 3429 ctxt->src.bytes = 1; 3430 fastop(ctxt, em_or); 3431 3432 return X86EMUL_CONTINUE; 3433 } 3434 3435 static int em_aad(struct x86_emulate_ctxt *ctxt) 3436 { 3437 u8 al = ctxt->dst.val & 0xff; 3438 u8 ah = (ctxt->dst.val >> 8) & 0xff; 3439 3440 al = (al + (ah * ctxt->src.val)) & 0xff; 3441 3442 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al; 3443 3444 /* Set PF, ZF, SF */ 3445 ctxt->src.type = OP_IMM; 3446 ctxt->src.val = 0; 3447 ctxt->src.bytes = 1; 3448 fastop(ctxt, em_or); 3449 3450 return X86EMUL_CONTINUE; 3451 } 3452 3453 static int em_call(struct x86_emulate_ctxt *ctxt) 3454 { 3455 int rc; 3456 long rel = ctxt->src.val; 3457 3458 ctxt->src.val = (unsigned long)ctxt->_eip; 3459 rc = jmp_rel(ctxt, rel); 3460 if (rc != X86EMUL_CONTINUE) 3461 return rc; 3462 return em_push(ctxt); 3463 } 3464 3465 static int em_call_far(struct x86_emulate_ctxt *ctxt) 3466 { 3467 u16 sel, old_cs; 3468 ulong old_eip; 3469 int rc; 3470 struct desc_struct old_desc, new_desc; 3471 const struct x86_emulate_ops *ops = ctxt->ops; 3472 int cpl = ctxt->ops->cpl(ctxt); 3473 enum x86emul_mode prev_mode = ctxt->mode; 3474 3475 old_eip = ctxt->_eip; 3476 ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS); 3477 3478 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); 3479 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, 3480 X86_TRANSFER_CALL_JMP, &new_desc); 3481 if (rc != X86EMUL_CONTINUE) 3482 return rc; 3483 3484 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc); 3485 if (rc != X86EMUL_CONTINUE) 3486 goto fail; 3487 3488 ctxt->src.val = old_cs; 3489 rc = em_push(ctxt); 3490 if (rc != X86EMUL_CONTINUE) 3491 goto fail; 3492 3493 ctxt->src.val = old_eip; 3494 rc = em_push(ctxt); 3495 /* If we failed, we tainted the memory, but the very least we should 3496 restore cs */ 3497 if (rc != X86EMUL_CONTINUE) { 3498 pr_warn_once("faulting far call emulation tainted memory\n"); 3499 goto fail; 3500 } 3501 return rc; 3502 fail: 3503 ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS); 3504 ctxt->mode = prev_mode; 3505 return rc; 3506 3507 } 3508 3509 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt) 3510 { 3511 int rc; 3512 unsigned long eip; 3513 3514 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); 3515 if (rc != X86EMUL_CONTINUE) 3516 return rc; 3517 rc = assign_eip_near(ctxt, eip); 3518 if (rc != X86EMUL_CONTINUE) 3519 return rc; 3520 rsp_increment(ctxt, ctxt->src.val); 3521 return X86EMUL_CONTINUE; 3522 } 3523 3524 static int em_xchg(struct x86_emulate_ctxt *ctxt) 3525 { 3526 /* Write back the register source. */ 3527 ctxt->src.val = ctxt->dst.val; 3528 write_register_operand(&ctxt->src); 3529 3530 /* Write back the memory destination with implicit LOCK prefix. */ 3531 ctxt->dst.val = ctxt->src.orig_val; 3532 ctxt->lock_prefix = 1; 3533 return X86EMUL_CONTINUE; 3534 } 3535 3536 static int em_imul_3op(struct x86_emulate_ctxt *ctxt) 3537 { 3538 ctxt->dst.val = ctxt->src2.val; 3539 return fastop(ctxt, em_imul); 3540 } 3541 3542 static int em_cwd(struct x86_emulate_ctxt *ctxt) 3543 { 3544 ctxt->dst.type = OP_REG; 3545 ctxt->dst.bytes = ctxt->src.bytes; 3546 ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); 3547 ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1); 3548 3549 return X86EMUL_CONTINUE; 3550 } 3551 3552 static int em_rdpid(struct x86_emulate_ctxt *ctxt) 3553 { 3554 u64 tsc_aux = 0; 3555 3556 if (!ctxt->ops->guest_has_rdpid(ctxt)) 3557 return emulate_ud(ctxt); 3558 3559 ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux); 3560 ctxt->dst.val = tsc_aux; 3561 return X86EMUL_CONTINUE; 3562 } 3563 3564 static int em_rdtsc(struct x86_emulate_ctxt *ctxt) 3565 { 3566 u64 tsc = 0; 3567 3568 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc); 3569 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc; 3570 *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32; 3571 return X86EMUL_CONTINUE; 3572 } 3573 3574 static int em_rdpmc(struct x86_emulate_ctxt *ctxt) 3575 { 3576 u64 pmc; 3577 3578 if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc)) 3579 return emulate_gp(ctxt, 0); 3580 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc; 3581 *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32; 3582 return X86EMUL_CONTINUE; 3583 } 3584 3585 static int em_mov(struct x86_emulate_ctxt *ctxt) 3586 { 3587 memcpy(ctxt->dst.valptr, ctxt->src.valptr, sizeof(ctxt->src.valptr)); 3588 return X86EMUL_CONTINUE; 3589 } 3590 3591 static int em_movbe(struct x86_emulate_ctxt *ctxt) 3592 { 3593 u16 tmp; 3594 3595 if (!ctxt->ops->guest_has_movbe(ctxt)) 3596 return emulate_ud(ctxt); 3597 3598 switch (ctxt->op_bytes) { 3599 case 2: 3600 /* 3601 * From MOVBE definition: "...When the operand size is 16 bits, 3602 * the upper word of the destination register remains unchanged 3603 * ..." 3604 * 3605 * Both casting ->valptr and ->val to u16 breaks strict aliasing 3606 * rules so we have to do the operation almost per hand. 3607 */ 3608 tmp = (u16)ctxt->src.val; 3609 ctxt->dst.val &= ~0xffffUL; 3610 ctxt->dst.val |= (unsigned long)swab16(tmp); 3611 break; 3612 case 4: 3613 ctxt->dst.val = swab32((u32)ctxt->src.val); 3614 break; 3615 case 8: 3616 ctxt->dst.val = swab64(ctxt->src.val); 3617 break; 3618 default: 3619 BUG(); 3620 } 3621 return X86EMUL_CONTINUE; 3622 } 3623 3624 static int em_cr_write(struct x86_emulate_ctxt *ctxt) 3625 { 3626 if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val)) 3627 return emulate_gp(ctxt, 0); 3628 3629 /* Disable writeback. */ 3630 ctxt->dst.type = OP_NONE; 3631 return X86EMUL_CONTINUE; 3632 } 3633 3634 static int em_dr_write(struct x86_emulate_ctxt *ctxt) 3635 { 3636 unsigned long val; 3637 3638 if (ctxt->mode == X86EMUL_MODE_PROT64) 3639 val = ctxt->src.val & ~0ULL; 3640 else 3641 val = ctxt->src.val & ~0U; 3642 3643 /* #UD condition is already handled. */ 3644 if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0) 3645 return emulate_gp(ctxt, 0); 3646 3647 /* Disable writeback. */ 3648 ctxt->dst.type = OP_NONE; 3649 return X86EMUL_CONTINUE; 3650 } 3651 3652 static int em_wrmsr(struct x86_emulate_ctxt *ctxt) 3653 { 3654 u64 msr_index = reg_read(ctxt, VCPU_REGS_RCX); 3655 u64 msr_data; 3656 int r; 3657 3658 msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX) 3659 | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32); 3660 r = ctxt->ops->set_msr_with_filter(ctxt, msr_index, msr_data); 3661 3662 if (r == X86EMUL_IO_NEEDED) 3663 return r; 3664 3665 if (r > 0) 3666 return emulate_gp(ctxt, 0); 3667 3668 return r < 0 ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; 3669 } 3670 3671 static int em_rdmsr(struct x86_emulate_ctxt *ctxt) 3672 { 3673 u64 msr_index = reg_read(ctxt, VCPU_REGS_RCX); 3674 u64 msr_data; 3675 int r; 3676 3677 r = ctxt->ops->get_msr_with_filter(ctxt, msr_index, &msr_data); 3678 3679 if (r == X86EMUL_IO_NEEDED) 3680 return r; 3681 3682 if (r) 3683 return emulate_gp(ctxt, 0); 3684 3685 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data; 3686 *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32; 3687 return X86EMUL_CONTINUE; 3688 } 3689 3690 static int em_store_sreg(struct x86_emulate_ctxt *ctxt, int segment) 3691 { 3692 if (segment > VCPU_SREG_GS && 3693 (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && 3694 ctxt->ops->cpl(ctxt) > 0) 3695 return emulate_gp(ctxt, 0); 3696 3697 ctxt->dst.val = get_segment_selector(ctxt, segment); 3698 if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM) 3699 ctxt->dst.bytes = 2; 3700 return X86EMUL_CONTINUE; 3701 } 3702 3703 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt) 3704 { 3705 if (ctxt->modrm_reg > VCPU_SREG_GS) 3706 return emulate_ud(ctxt); 3707 3708 return em_store_sreg(ctxt, ctxt->modrm_reg); 3709 } 3710 3711 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt) 3712 { 3713 u16 sel = ctxt->src.val; 3714 3715 if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS) 3716 return emulate_ud(ctxt); 3717 3718 if (ctxt->modrm_reg == VCPU_SREG_SS) 3719 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; 3720 3721 /* Disable writeback. */ 3722 ctxt->dst.type = OP_NONE; 3723 return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg); 3724 } 3725 3726 static int em_sldt(struct x86_emulate_ctxt *ctxt) 3727 { 3728 return em_store_sreg(ctxt, VCPU_SREG_LDTR); 3729 } 3730 3731 static int em_lldt(struct x86_emulate_ctxt *ctxt) 3732 { 3733 u16 sel = ctxt->src.val; 3734 3735 /* Disable writeback. */ 3736 ctxt->dst.type = OP_NONE; 3737 return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR); 3738 } 3739 3740 static int em_str(struct x86_emulate_ctxt *ctxt) 3741 { 3742 return em_store_sreg(ctxt, VCPU_SREG_TR); 3743 } 3744 3745 static int em_ltr(struct x86_emulate_ctxt *ctxt) 3746 { 3747 u16 sel = ctxt->src.val; 3748 3749 /* Disable writeback. */ 3750 ctxt->dst.type = OP_NONE; 3751 return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR); 3752 } 3753 3754 static int em_invlpg(struct x86_emulate_ctxt *ctxt) 3755 { 3756 int rc; 3757 ulong linear; 3758 3759 rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear); 3760 if (rc == X86EMUL_CONTINUE) 3761 ctxt->ops->invlpg(ctxt, linear); 3762 /* Disable writeback. */ 3763 ctxt->dst.type = OP_NONE; 3764 return X86EMUL_CONTINUE; 3765 } 3766 3767 static int em_clts(struct x86_emulate_ctxt *ctxt) 3768 { 3769 ulong cr0; 3770 3771 cr0 = ctxt->ops->get_cr(ctxt, 0); 3772 cr0 &= ~X86_CR0_TS; 3773 ctxt->ops->set_cr(ctxt, 0, cr0); 3774 return X86EMUL_CONTINUE; 3775 } 3776 3777 static int em_hypercall(struct x86_emulate_ctxt *ctxt) 3778 { 3779 int rc = ctxt->ops->fix_hypercall(ctxt); 3780 3781 if (rc != X86EMUL_CONTINUE) 3782 return rc; 3783 3784 /* Let the processor re-execute the fixed hypercall */ 3785 ctxt->_eip = ctxt->eip; 3786 /* Disable writeback. */ 3787 ctxt->dst.type = OP_NONE; 3788 return X86EMUL_CONTINUE; 3789 } 3790 3791 static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt, 3792 void (*get)(struct x86_emulate_ctxt *ctxt, 3793 struct desc_ptr *ptr)) 3794 { 3795 struct desc_ptr desc_ptr; 3796 3797 if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && 3798 ctxt->ops->cpl(ctxt) > 0) 3799 return emulate_gp(ctxt, 0); 3800 3801 if (ctxt->mode == X86EMUL_MODE_PROT64) 3802 ctxt->op_bytes = 8; 3803 get(ctxt, &desc_ptr); 3804 if (ctxt->op_bytes == 2) { 3805 ctxt->op_bytes = 4; 3806 desc_ptr.address &= 0x00ffffff; 3807 } 3808 /* Disable writeback. */ 3809 ctxt->dst.type = OP_NONE; 3810 return segmented_write_std(ctxt, ctxt->dst.addr.mem, 3811 &desc_ptr, 2 + ctxt->op_bytes); 3812 } 3813 3814 static int em_sgdt(struct x86_emulate_ctxt *ctxt) 3815 { 3816 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt); 3817 } 3818 3819 static int em_sidt(struct x86_emulate_ctxt *ctxt) 3820 { 3821 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt); 3822 } 3823 3824 static int em_lgdt_lidt(struct x86_emulate_ctxt *ctxt, bool lgdt) 3825 { 3826 struct desc_ptr desc_ptr; 3827 int rc; 3828 3829 if (ctxt->mode == X86EMUL_MODE_PROT64) 3830 ctxt->op_bytes = 8; 3831 rc = read_descriptor(ctxt, ctxt->src.addr.mem, 3832 &desc_ptr.size, &desc_ptr.address, 3833 ctxt->op_bytes); 3834 if (rc != X86EMUL_CONTINUE) 3835 return rc; 3836 if (ctxt->mode == X86EMUL_MODE_PROT64 && 3837 emul_is_noncanonical_address(desc_ptr.address, ctxt)) 3838 return emulate_gp(ctxt, 0); 3839 if (lgdt) 3840 ctxt->ops->set_gdt(ctxt, &desc_ptr); 3841 else 3842 ctxt->ops->set_idt(ctxt, &desc_ptr); 3843 /* Disable writeback. */ 3844 ctxt->dst.type = OP_NONE; 3845 return X86EMUL_CONTINUE; 3846 } 3847 3848 static int em_lgdt(struct x86_emulate_ctxt *ctxt) 3849 { 3850 return em_lgdt_lidt(ctxt, true); 3851 } 3852 3853 static int em_lidt(struct x86_emulate_ctxt *ctxt) 3854 { 3855 return em_lgdt_lidt(ctxt, false); 3856 } 3857 3858 static int em_smsw(struct x86_emulate_ctxt *ctxt) 3859 { 3860 if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && 3861 ctxt->ops->cpl(ctxt) > 0) 3862 return emulate_gp(ctxt, 0); 3863 3864 if (ctxt->dst.type == OP_MEM) 3865 ctxt->dst.bytes = 2; 3866 ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0); 3867 return X86EMUL_CONTINUE; 3868 } 3869 3870 static int em_lmsw(struct x86_emulate_ctxt *ctxt) 3871 { 3872 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul) 3873 | (ctxt->src.val & 0x0f)); 3874 ctxt->dst.type = OP_NONE; 3875 return X86EMUL_CONTINUE; 3876 } 3877 3878 static int em_loop(struct x86_emulate_ctxt *ctxt) 3879 { 3880 int rc = X86EMUL_CONTINUE; 3881 3882 register_address_increment(ctxt, VCPU_REGS_RCX, -1); 3883 if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) && 3884 (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags))) 3885 rc = jmp_rel(ctxt, ctxt->src.val); 3886 3887 return rc; 3888 } 3889 3890 static int em_jcxz(struct x86_emulate_ctxt *ctxt) 3891 { 3892 int rc = X86EMUL_CONTINUE; 3893 3894 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) 3895 rc = jmp_rel(ctxt, ctxt->src.val); 3896 3897 return rc; 3898 } 3899 3900 static int em_in(struct x86_emulate_ctxt *ctxt) 3901 { 3902 if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val, 3903 &ctxt->dst.val)) 3904 return X86EMUL_IO_NEEDED; 3905 3906 return X86EMUL_CONTINUE; 3907 } 3908 3909 static int em_out(struct x86_emulate_ctxt *ctxt) 3910 { 3911 ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val, 3912 &ctxt->src.val, 1); 3913 /* Disable writeback. */ 3914 ctxt->dst.type = OP_NONE; 3915 return X86EMUL_CONTINUE; 3916 } 3917 3918 static int em_cli(struct x86_emulate_ctxt *ctxt) 3919 { 3920 if (emulator_bad_iopl(ctxt)) 3921 return emulate_gp(ctxt, 0); 3922 3923 ctxt->eflags &= ~X86_EFLAGS_IF; 3924 return X86EMUL_CONTINUE; 3925 } 3926 3927 static int em_sti(struct x86_emulate_ctxt *ctxt) 3928 { 3929 if (emulator_bad_iopl(ctxt)) 3930 return emulate_gp(ctxt, 0); 3931 3932 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; 3933 ctxt->eflags |= X86_EFLAGS_IF; 3934 return X86EMUL_CONTINUE; 3935 } 3936 3937 static int em_cpuid(struct x86_emulate_ctxt *ctxt) 3938 { 3939 u32 eax, ebx, ecx, edx; 3940 u64 msr = 0; 3941 3942 ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr); 3943 if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT && 3944 ctxt->ops->cpl(ctxt)) { 3945 return emulate_gp(ctxt, 0); 3946 } 3947 3948 eax = reg_read(ctxt, VCPU_REGS_RAX); 3949 ecx = reg_read(ctxt, VCPU_REGS_RCX); 3950 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); 3951 *reg_write(ctxt, VCPU_REGS_RAX) = eax; 3952 *reg_write(ctxt, VCPU_REGS_RBX) = ebx; 3953 *reg_write(ctxt, VCPU_REGS_RCX) = ecx; 3954 *reg_write(ctxt, VCPU_REGS_RDX) = edx; 3955 return X86EMUL_CONTINUE; 3956 } 3957 3958 static int em_sahf(struct x86_emulate_ctxt *ctxt) 3959 { 3960 u32 flags; 3961 3962 flags = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | X86_EFLAGS_ZF | 3963 X86_EFLAGS_SF; 3964 flags &= *reg_rmw(ctxt, VCPU_REGS_RAX) >> 8; 3965 3966 ctxt->eflags &= ~0xffUL; 3967 ctxt->eflags |= flags | X86_EFLAGS_FIXED; 3968 return X86EMUL_CONTINUE; 3969 } 3970 3971 static int em_lahf(struct x86_emulate_ctxt *ctxt) 3972 { 3973 *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL; 3974 *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8; 3975 return X86EMUL_CONTINUE; 3976 } 3977 3978 static int em_bswap(struct x86_emulate_ctxt *ctxt) 3979 { 3980 switch (ctxt->op_bytes) { 3981 #ifdef CONFIG_X86_64 3982 case 8: 3983 asm("bswap %0" : "+r"(ctxt->dst.val)); 3984 break; 3985 #endif 3986 default: 3987 asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val)); 3988 break; 3989 } 3990 return X86EMUL_CONTINUE; 3991 } 3992 3993 static int em_clflush(struct x86_emulate_ctxt *ctxt) 3994 { 3995 /* emulating clflush regardless of cpuid */ 3996 return X86EMUL_CONTINUE; 3997 } 3998 3999 static int em_clflushopt(struct x86_emulate_ctxt *ctxt) 4000 { 4001 /* emulating clflushopt regardless of cpuid */ 4002 return X86EMUL_CONTINUE; 4003 } 4004 4005 static int em_movsxd(struct x86_emulate_ctxt *ctxt) 4006 { 4007 ctxt->dst.val = (s32) ctxt->src.val; 4008 return X86EMUL_CONTINUE; 4009 } 4010 4011 static int check_fxsr(struct x86_emulate_ctxt *ctxt) 4012 { 4013 if (!ctxt->ops->guest_has_fxsr(ctxt)) 4014 return emulate_ud(ctxt); 4015 4016 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 4017 return emulate_nm(ctxt); 4018 4019 /* 4020 * Don't emulate a case that should never be hit, instead of working 4021 * around a lack of fxsave64/fxrstor64 on old compilers. 4022 */ 4023 if (ctxt->mode >= X86EMUL_MODE_PROT64) 4024 return X86EMUL_UNHANDLEABLE; 4025 4026 return X86EMUL_CONTINUE; 4027 } 4028 4029 /* 4030 * Hardware doesn't save and restore XMM 0-7 without CR4.OSFXSR, but does save 4031 * and restore MXCSR. 4032 */ 4033 static size_t __fxstate_size(int nregs) 4034 { 4035 return offsetof(struct fxregs_state, xmm_space[0]) + nregs * 16; 4036 } 4037 4038 static inline size_t fxstate_size(struct x86_emulate_ctxt *ctxt) 4039 { 4040 bool cr4_osfxsr; 4041 if (ctxt->mode == X86EMUL_MODE_PROT64) 4042 return __fxstate_size(16); 4043 4044 cr4_osfxsr = ctxt->ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR; 4045 return __fxstate_size(cr4_osfxsr ? 8 : 0); 4046 } 4047 4048 /* 4049 * FXSAVE and FXRSTOR have 4 different formats depending on execution mode, 4050 * 1) 16 bit mode 4051 * 2) 32 bit mode 4052 * - like (1), but FIP and FDP (foo) are only 16 bit. At least Intel CPUs 4053 * preserve whole 32 bit values, though, so (1) and (2) are the same wrt. 4054 * save and restore 4055 * 3) 64-bit mode with REX.W prefix 4056 * - like (2), but XMM 8-15 are being saved and restored 4057 * 4) 64-bit mode without REX.W prefix 4058 * - like (3), but FIP and FDP are 64 bit 4059 * 4060 * Emulation uses (3) for (1) and (2) and preserves XMM 8-15 to reach the 4061 * desired result. (4) is not emulated. 4062 * 4063 * Note: Guest and host CPUID.(EAX=07H,ECX=0H):EBX[bit 13] (deprecate FPU CS 4064 * and FPU DS) should match. 4065 */ 4066 static int em_fxsave(struct x86_emulate_ctxt *ctxt) 4067 { 4068 struct fxregs_state fx_state; 4069 int rc; 4070 4071 rc = check_fxsr(ctxt); 4072 if (rc != X86EMUL_CONTINUE) 4073 return rc; 4074 4075 kvm_fpu_get(); 4076 4077 rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state)); 4078 4079 kvm_fpu_put(); 4080 4081 if (rc != X86EMUL_CONTINUE) 4082 return rc; 4083 4084 return segmented_write_std(ctxt, ctxt->memop.addr.mem, &fx_state, 4085 fxstate_size(ctxt)); 4086 } 4087 4088 /* 4089 * FXRSTOR might restore XMM registers not provided by the guest. Fill 4090 * in the host registers (via FXSAVE) instead, so they won't be modified. 4091 * (preemption has to stay disabled until FXRSTOR). 4092 * 4093 * Use noinline to keep the stack for other functions called by callers small. 4094 */ 4095 static noinline int fxregs_fixup(struct fxregs_state *fx_state, 4096 const size_t used_size) 4097 { 4098 struct fxregs_state fx_tmp; 4099 int rc; 4100 4101 rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_tmp)); 4102 memcpy((void *)fx_state + used_size, (void *)&fx_tmp + used_size, 4103 __fxstate_size(16) - used_size); 4104 4105 return rc; 4106 } 4107 4108 static int em_fxrstor(struct x86_emulate_ctxt *ctxt) 4109 { 4110 struct fxregs_state fx_state; 4111 int rc; 4112 size_t size; 4113 4114 rc = check_fxsr(ctxt); 4115 if (rc != X86EMUL_CONTINUE) 4116 return rc; 4117 4118 size = fxstate_size(ctxt); 4119 rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, size); 4120 if (rc != X86EMUL_CONTINUE) 4121 return rc; 4122 4123 kvm_fpu_get(); 4124 4125 if (size < __fxstate_size(16)) { 4126 rc = fxregs_fixup(&fx_state, size); 4127 if (rc != X86EMUL_CONTINUE) 4128 goto out; 4129 } 4130 4131 if (fx_state.mxcsr >> 16) { 4132 rc = emulate_gp(ctxt, 0); 4133 goto out; 4134 } 4135 4136 if (rc == X86EMUL_CONTINUE) 4137 rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state)); 4138 4139 out: 4140 kvm_fpu_put(); 4141 4142 return rc; 4143 } 4144 4145 static int em_xsetbv(struct x86_emulate_ctxt *ctxt) 4146 { 4147 u32 eax, ecx, edx; 4148 4149 eax = reg_read(ctxt, VCPU_REGS_RAX); 4150 edx = reg_read(ctxt, VCPU_REGS_RDX); 4151 ecx = reg_read(ctxt, VCPU_REGS_RCX); 4152 4153 if (ctxt->ops->set_xcr(ctxt, ecx, ((u64)edx << 32) | eax)) 4154 return emulate_gp(ctxt, 0); 4155 4156 return X86EMUL_CONTINUE; 4157 } 4158 4159 static bool valid_cr(int nr) 4160 { 4161 switch (nr) { 4162 case 0: 4163 case 2 ... 4: 4164 case 8: 4165 return true; 4166 default: 4167 return false; 4168 } 4169 } 4170 4171 static int check_cr_access(struct x86_emulate_ctxt *ctxt) 4172 { 4173 if (!valid_cr(ctxt->modrm_reg)) 4174 return emulate_ud(ctxt); 4175 4176 return X86EMUL_CONTINUE; 4177 } 4178 4179 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt) 4180 { 4181 unsigned long dr7; 4182 4183 ctxt->ops->get_dr(ctxt, 7, &dr7); 4184 4185 /* Check if DR7.Global_Enable is set */ 4186 return dr7 & (1 << 13); 4187 } 4188 4189 static int check_dr_read(struct x86_emulate_ctxt *ctxt) 4190 { 4191 int dr = ctxt->modrm_reg; 4192 u64 cr4; 4193 4194 if (dr > 7) 4195 return emulate_ud(ctxt); 4196 4197 cr4 = ctxt->ops->get_cr(ctxt, 4); 4198 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5)) 4199 return emulate_ud(ctxt); 4200 4201 if (check_dr7_gd(ctxt)) { 4202 ulong dr6; 4203 4204 ctxt->ops->get_dr(ctxt, 6, &dr6); 4205 dr6 &= ~DR_TRAP_BITS; 4206 dr6 |= DR6_BD | DR6_ACTIVE_LOW; 4207 ctxt->ops->set_dr(ctxt, 6, dr6); 4208 return emulate_db(ctxt); 4209 } 4210 4211 return X86EMUL_CONTINUE; 4212 } 4213 4214 static int check_dr_write(struct x86_emulate_ctxt *ctxt) 4215 { 4216 u64 new_val = ctxt->src.val64; 4217 int dr = ctxt->modrm_reg; 4218 4219 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL)) 4220 return emulate_gp(ctxt, 0); 4221 4222 return check_dr_read(ctxt); 4223 } 4224 4225 static int check_svme(struct x86_emulate_ctxt *ctxt) 4226 { 4227 u64 efer = 0; 4228 4229 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 4230 4231 if (!(efer & EFER_SVME)) 4232 return emulate_ud(ctxt); 4233 4234 return X86EMUL_CONTINUE; 4235 } 4236 4237 static int check_svme_pa(struct x86_emulate_ctxt *ctxt) 4238 { 4239 u64 rax = reg_read(ctxt, VCPU_REGS_RAX); 4240 4241 /* Valid physical address? */ 4242 if (rax & 0xffff000000000000ULL) 4243 return emulate_gp(ctxt, 0); 4244 4245 return check_svme(ctxt); 4246 } 4247 4248 static int check_rdtsc(struct x86_emulate_ctxt *ctxt) 4249 { 4250 u64 cr4 = ctxt->ops->get_cr(ctxt, 4); 4251 4252 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt)) 4253 return emulate_gp(ctxt, 0); 4254 4255 return X86EMUL_CONTINUE; 4256 } 4257 4258 static int check_rdpmc(struct x86_emulate_ctxt *ctxt) 4259 { 4260 u64 cr4 = ctxt->ops->get_cr(ctxt, 4); 4261 u64 rcx = reg_read(ctxt, VCPU_REGS_RCX); 4262 4263 /* 4264 * VMware allows access to these Pseduo-PMCs even when read via RDPMC 4265 * in Ring3 when CR4.PCE=0. 4266 */ 4267 if (enable_vmware_backdoor && is_vmware_backdoor_pmc(rcx)) 4268 return X86EMUL_CONTINUE; 4269 4270 /* 4271 * If CR4.PCE is set, the SDM requires CPL=0 or CR0.PE=0. The CR0.PE 4272 * check however is unnecessary because CPL is always 0 outside 4273 * protected mode. 4274 */ 4275 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || 4276 ctxt->ops->check_pmc(ctxt, rcx)) 4277 return emulate_gp(ctxt, 0); 4278 4279 return X86EMUL_CONTINUE; 4280 } 4281 4282 static int check_perm_in(struct x86_emulate_ctxt *ctxt) 4283 { 4284 ctxt->dst.bytes = min(ctxt->dst.bytes, 4u); 4285 if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes)) 4286 return emulate_gp(ctxt, 0); 4287 4288 return X86EMUL_CONTINUE; 4289 } 4290 4291 static int check_perm_out(struct x86_emulate_ctxt *ctxt) 4292 { 4293 ctxt->src.bytes = min(ctxt->src.bytes, 4u); 4294 if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes)) 4295 return emulate_gp(ctxt, 0); 4296 4297 return X86EMUL_CONTINUE; 4298 } 4299 4300 #define D(_y) { .flags = (_y) } 4301 #define DI(_y, _i) { .flags = (_y)|Intercept, .intercept = x86_intercept_##_i } 4302 #define DIP(_y, _i, _p) { .flags = (_y)|Intercept|CheckPerm, \ 4303 .intercept = x86_intercept_##_i, .check_perm = (_p) } 4304 #define N D(NotImpl) 4305 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) } 4306 #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) } 4307 #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) } 4308 #define ID(_f, _i) { .flags = ((_f) | InstrDual | ModRM), .u.idual = (_i) } 4309 #define MD(_f, _m) { .flags = ((_f) | ModeDual), .u.mdual = (_m) } 4310 #define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) } 4311 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) } 4312 #define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) } 4313 #define II(_f, _e, _i) \ 4314 { .flags = (_f)|Intercept, .u.execute = (_e), .intercept = x86_intercept_##_i } 4315 #define IIP(_f, _e, _i, _p) \ 4316 { .flags = (_f)|Intercept|CheckPerm, .u.execute = (_e), \ 4317 .intercept = x86_intercept_##_i, .check_perm = (_p) } 4318 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) } 4319 4320 #define D2bv(_f) D((_f) | ByteOp), D(_f) 4321 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p) 4322 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e) 4323 #define F2bv(_f, _e) F((_f) | ByteOp, _e), F(_f, _e) 4324 #define I2bvIP(_f, _e, _i, _p) \ 4325 IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p) 4326 4327 #define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e), \ 4328 F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \ 4329 F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e) 4330 4331 static const struct opcode group7_rm0[] = { 4332 N, 4333 I(SrcNone | Priv | EmulateOnUD, em_hypercall), 4334 N, N, N, N, N, N, 4335 }; 4336 4337 static const struct opcode group7_rm1[] = { 4338 DI(SrcNone | Priv, monitor), 4339 DI(SrcNone | Priv, mwait), 4340 N, N, N, N, N, N, 4341 }; 4342 4343 static const struct opcode group7_rm2[] = { 4344 N, 4345 II(ImplicitOps | Priv, em_xsetbv, xsetbv), 4346 N, N, N, N, N, N, 4347 }; 4348 4349 static const struct opcode group7_rm3[] = { 4350 DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa), 4351 II(SrcNone | Prot | EmulateOnUD, em_hypercall, vmmcall), 4352 DIP(SrcNone | Prot | Priv, vmload, check_svme_pa), 4353 DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa), 4354 DIP(SrcNone | Prot | Priv, stgi, check_svme), 4355 DIP(SrcNone | Prot | Priv, clgi, check_svme), 4356 DIP(SrcNone | Prot | Priv, skinit, check_svme), 4357 DIP(SrcNone | Prot | Priv, invlpga, check_svme), 4358 }; 4359 4360 static const struct opcode group7_rm7[] = { 4361 N, 4362 DIP(SrcNone, rdtscp, check_rdtsc), 4363 N, N, N, N, N, N, 4364 }; 4365 4366 static const struct opcode group1[] = { 4367 F(Lock, em_add), 4368 F(Lock | PageTable, em_or), 4369 F(Lock, em_adc), 4370 F(Lock, em_sbb), 4371 F(Lock | PageTable, em_and), 4372 F(Lock, em_sub), 4373 F(Lock, em_xor), 4374 F(NoWrite, em_cmp), 4375 }; 4376 4377 static const struct opcode group1A[] = { 4378 I(DstMem | SrcNone | Mov | Stack | IncSP | TwoMemOp, em_pop), N, N, N, N, N, N, N, 4379 }; 4380 4381 static const struct opcode group2[] = { 4382 F(DstMem | ModRM, em_rol), 4383 F(DstMem | ModRM, em_ror), 4384 F(DstMem | ModRM, em_rcl), 4385 F(DstMem | ModRM, em_rcr), 4386 F(DstMem | ModRM, em_shl), 4387 F(DstMem | ModRM, em_shr), 4388 F(DstMem | ModRM, em_shl), 4389 F(DstMem | ModRM, em_sar), 4390 }; 4391 4392 static const struct opcode group3[] = { 4393 F(DstMem | SrcImm | NoWrite, em_test), 4394 F(DstMem | SrcImm | NoWrite, em_test), 4395 F(DstMem | SrcNone | Lock, em_not), 4396 F(DstMem | SrcNone | Lock, em_neg), 4397 F(DstXacc | Src2Mem, em_mul_ex), 4398 F(DstXacc | Src2Mem, em_imul_ex), 4399 F(DstXacc | Src2Mem, em_div_ex), 4400 F(DstXacc | Src2Mem, em_idiv_ex), 4401 }; 4402 4403 static const struct opcode group4[] = { 4404 F(ByteOp | DstMem | SrcNone | Lock, em_inc), 4405 F(ByteOp | DstMem | SrcNone | Lock, em_dec), 4406 N, N, N, N, N, N, 4407 }; 4408 4409 static const struct opcode group5[] = { 4410 F(DstMem | SrcNone | Lock, em_inc), 4411 F(DstMem | SrcNone | Lock, em_dec), 4412 I(SrcMem | NearBranch | IsBranch, em_call_near_abs), 4413 I(SrcMemFAddr | ImplicitOps | IsBranch, em_call_far), 4414 I(SrcMem | NearBranch | IsBranch, em_jmp_abs), 4415 I(SrcMemFAddr | ImplicitOps | IsBranch, em_jmp_far), 4416 I(SrcMem | Stack | TwoMemOp, em_push), D(Undefined), 4417 }; 4418 4419 static const struct opcode group6[] = { 4420 II(Prot | DstMem, em_sldt, sldt), 4421 II(Prot | DstMem, em_str, str), 4422 II(Prot | Priv | SrcMem16, em_lldt, lldt), 4423 II(Prot | Priv | SrcMem16, em_ltr, ltr), 4424 N, N, N, N, 4425 }; 4426 4427 static const struct group_dual group7 = { { 4428 II(Mov | DstMem, em_sgdt, sgdt), 4429 II(Mov | DstMem, em_sidt, sidt), 4430 II(SrcMem | Priv, em_lgdt, lgdt), 4431 II(SrcMem | Priv, em_lidt, lidt), 4432 II(SrcNone | DstMem | Mov, em_smsw, smsw), N, 4433 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), 4434 II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg), 4435 }, { 4436 EXT(0, group7_rm0), 4437 EXT(0, group7_rm1), 4438 EXT(0, group7_rm2), 4439 EXT(0, group7_rm3), 4440 II(SrcNone | DstMem | Mov, em_smsw, smsw), N, 4441 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), 4442 EXT(0, group7_rm7), 4443 } }; 4444 4445 static const struct opcode group8[] = { 4446 N, N, N, N, 4447 F(DstMem | SrcImmByte | NoWrite, em_bt), 4448 F(DstMem | SrcImmByte | Lock | PageTable, em_bts), 4449 F(DstMem | SrcImmByte | Lock, em_btr), 4450 F(DstMem | SrcImmByte | Lock | PageTable, em_btc), 4451 }; 4452 4453 /* 4454 * The "memory" destination is actually always a register, since we come 4455 * from the register case of group9. 4456 */ 4457 static const struct gprefix pfx_0f_c7_7 = { 4458 N, N, N, II(DstMem | ModRM | Op3264 | EmulateOnUD, em_rdpid, rdpid), 4459 }; 4460 4461 4462 static const struct group_dual group9 = { { 4463 N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N, 4464 }, { 4465 N, N, N, N, N, N, N, 4466 GP(0, &pfx_0f_c7_7), 4467 } }; 4468 4469 static const struct opcode group11[] = { 4470 I(DstMem | SrcImm | Mov | PageTable, em_mov), 4471 X7(D(Undefined)), 4472 }; 4473 4474 static const struct gprefix pfx_0f_ae_7 = { 4475 I(SrcMem | ByteOp, em_clflush), I(SrcMem | ByteOp, em_clflushopt), N, N, 4476 }; 4477 4478 static const struct group_dual group15 = { { 4479 I(ModRM | Aligned16, em_fxsave), 4480 I(ModRM | Aligned16, em_fxrstor), 4481 N, N, N, N, N, GP(0, &pfx_0f_ae_7), 4482 }, { 4483 N, N, N, N, N, N, N, N, 4484 } }; 4485 4486 static const struct gprefix pfx_0f_6f_0f_7f = { 4487 I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov), 4488 }; 4489 4490 static const struct instr_dual instr_dual_0f_2b = { 4491 I(0, em_mov), N 4492 }; 4493 4494 static const struct gprefix pfx_0f_2b = { 4495 ID(0, &instr_dual_0f_2b), ID(0, &instr_dual_0f_2b), N, N, 4496 }; 4497 4498 static const struct gprefix pfx_0f_10_0f_11 = { 4499 I(Unaligned, em_mov), I(Unaligned, em_mov), N, N, 4500 }; 4501 4502 static const struct gprefix pfx_0f_28_0f_29 = { 4503 I(Aligned, em_mov), I(Aligned, em_mov), N, N, 4504 }; 4505 4506 static const struct gprefix pfx_0f_e7 = { 4507 N, I(Sse, em_mov), N, N, 4508 }; 4509 4510 static const struct escape escape_d9 = { { 4511 N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstcw), 4512 }, { 4513 /* 0xC0 - 0xC7 */ 4514 N, N, N, N, N, N, N, N, 4515 /* 0xC8 - 0xCF */ 4516 N, N, N, N, N, N, N, N, 4517 /* 0xD0 - 0xC7 */ 4518 N, N, N, N, N, N, N, N, 4519 /* 0xD8 - 0xDF */ 4520 N, N, N, N, N, N, N, N, 4521 /* 0xE0 - 0xE7 */ 4522 N, N, N, N, N, N, N, N, 4523 /* 0xE8 - 0xEF */ 4524 N, N, N, N, N, N, N, N, 4525 /* 0xF0 - 0xF7 */ 4526 N, N, N, N, N, N, N, N, 4527 /* 0xF8 - 0xFF */ 4528 N, N, N, N, N, N, N, N, 4529 } }; 4530 4531 static const struct escape escape_db = { { 4532 N, N, N, N, N, N, N, N, 4533 }, { 4534 /* 0xC0 - 0xC7 */ 4535 N, N, N, N, N, N, N, N, 4536 /* 0xC8 - 0xCF */ 4537 N, N, N, N, N, N, N, N, 4538 /* 0xD0 - 0xC7 */ 4539 N, N, N, N, N, N, N, N, 4540 /* 0xD8 - 0xDF */ 4541 N, N, N, N, N, N, N, N, 4542 /* 0xE0 - 0xE7 */ 4543 N, N, N, I(ImplicitOps, em_fninit), N, N, N, N, 4544 /* 0xE8 - 0xEF */ 4545 N, N, N, N, N, N, N, N, 4546 /* 0xF0 - 0xF7 */ 4547 N, N, N, N, N, N, N, N, 4548 /* 0xF8 - 0xFF */ 4549 N, N, N, N, N, N, N, N, 4550 } }; 4551 4552 static const struct escape escape_dd = { { 4553 N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstsw), 4554 }, { 4555 /* 0xC0 - 0xC7 */ 4556 N, N, N, N, N, N, N, N, 4557 /* 0xC8 - 0xCF */ 4558 N, N, N, N, N, N, N, N, 4559 /* 0xD0 - 0xC7 */ 4560 N, N, N, N, N, N, N, N, 4561 /* 0xD8 - 0xDF */ 4562 N, N, N, N, N, N, N, N, 4563 /* 0xE0 - 0xE7 */ 4564 N, N, N, N, N, N, N, N, 4565 /* 0xE8 - 0xEF */ 4566 N, N, N, N, N, N, N, N, 4567 /* 0xF0 - 0xF7 */ 4568 N, N, N, N, N, N, N, N, 4569 /* 0xF8 - 0xFF */ 4570 N, N, N, N, N, N, N, N, 4571 } }; 4572 4573 static const struct instr_dual instr_dual_0f_c3 = { 4574 I(DstMem | SrcReg | ModRM | No16 | Mov, em_mov), N 4575 }; 4576 4577 static const struct mode_dual mode_dual_63 = { 4578 N, I(DstReg | SrcMem32 | ModRM | Mov, em_movsxd) 4579 }; 4580 4581 static const struct instr_dual instr_dual_8d = { 4582 D(DstReg | SrcMem | ModRM | NoAccess), N 4583 }; 4584 4585 static const struct opcode opcode_table[256] = { 4586 /* 0x00 - 0x07 */ 4587 F6ALU(Lock, em_add), 4588 I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg), 4589 I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg), 4590 /* 0x08 - 0x0F */ 4591 F6ALU(Lock | PageTable, em_or), 4592 I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg), 4593 N, 4594 /* 0x10 - 0x17 */ 4595 F6ALU(Lock, em_adc), 4596 I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg), 4597 I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg), 4598 /* 0x18 - 0x1F */ 4599 F6ALU(Lock, em_sbb), 4600 I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg), 4601 I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg), 4602 /* 0x20 - 0x27 */ 4603 F6ALU(Lock | PageTable, em_and), N, N, 4604 /* 0x28 - 0x2F */ 4605 F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das), 4606 /* 0x30 - 0x37 */ 4607 F6ALU(Lock, em_xor), N, N, 4608 /* 0x38 - 0x3F */ 4609 F6ALU(NoWrite, em_cmp), N, N, 4610 /* 0x40 - 0x4F */ 4611 X8(F(DstReg, em_inc)), X8(F(DstReg, em_dec)), 4612 /* 0x50 - 0x57 */ 4613 X8(I(SrcReg | Stack, em_push)), 4614 /* 0x58 - 0x5F */ 4615 X8(I(DstReg | Stack, em_pop)), 4616 /* 0x60 - 0x67 */ 4617 I(ImplicitOps | Stack | No64, em_pusha), 4618 I(ImplicitOps | Stack | No64, em_popa), 4619 N, MD(ModRM, &mode_dual_63), 4620 N, N, N, N, 4621 /* 0x68 - 0x6F */ 4622 I(SrcImm | Mov | Stack, em_push), 4623 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op), 4624 I(SrcImmByte | Mov | Stack, em_push), 4625 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op), 4626 I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */ 4627 I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */ 4628 /* 0x70 - 0x7F */ 4629 X16(D(SrcImmByte | NearBranch | IsBranch)), 4630 /* 0x80 - 0x87 */ 4631 G(ByteOp | DstMem | SrcImm, group1), 4632 G(DstMem | SrcImm, group1), 4633 G(ByteOp | DstMem | SrcImm | No64, group1), 4634 G(DstMem | SrcImmByte, group1), 4635 F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test), 4636 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg), 4637 /* 0x88 - 0x8F */ 4638 I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov), 4639 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov), 4640 I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg), 4641 ID(0, &instr_dual_8d), 4642 I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm), 4643 G(0, group1A), 4644 /* 0x90 - 0x97 */ 4645 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)), 4646 /* 0x98 - 0x9F */ 4647 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd), 4648 I(SrcImmFAddr | No64 | IsBranch, em_call_far), N, 4649 II(ImplicitOps | Stack, em_pushf, pushf), 4650 II(ImplicitOps | Stack, em_popf, popf), 4651 I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf), 4652 /* 0xA0 - 0xA7 */ 4653 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov), 4654 I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov), 4655 I2bv(SrcSI | DstDI | Mov | String | TwoMemOp, em_mov), 4656 F2bv(SrcSI | DstDI | String | NoWrite | TwoMemOp, em_cmp_r), 4657 /* 0xA8 - 0xAF */ 4658 F2bv(DstAcc | SrcImm | NoWrite, em_test), 4659 I2bv(SrcAcc | DstDI | Mov | String, em_mov), 4660 I2bv(SrcSI | DstAcc | Mov | String, em_mov), 4661 F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r), 4662 /* 0xB0 - 0xB7 */ 4663 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)), 4664 /* 0xB8 - 0xBF */ 4665 X8(I(DstReg | SrcImm64 | Mov, em_mov)), 4666 /* 0xC0 - 0xC7 */ 4667 G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2), 4668 I(ImplicitOps | NearBranch | SrcImmU16 | IsBranch, em_ret_near_imm), 4669 I(ImplicitOps | NearBranch | IsBranch, em_ret), 4670 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg), 4671 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg), 4672 G(ByteOp, group11), G(0, group11), 4673 /* 0xC8 - 0xCF */ 4674 I(Stack | SrcImmU16 | Src2ImmByte | IsBranch, em_enter), 4675 I(Stack | IsBranch, em_leave), 4676 I(ImplicitOps | SrcImmU16 | IsBranch, em_ret_far_imm), 4677 I(ImplicitOps | IsBranch, em_ret_far), 4678 D(ImplicitOps | IsBranch), DI(SrcImmByte | IsBranch, intn), 4679 D(ImplicitOps | No64 | IsBranch), 4680 II(ImplicitOps | IsBranch, em_iret, iret), 4681 /* 0xD0 - 0xD7 */ 4682 G(Src2One | ByteOp, group2), G(Src2One, group2), 4683 G(Src2CL | ByteOp, group2), G(Src2CL, group2), 4684 I(DstAcc | SrcImmUByte | No64, em_aam), 4685 I(DstAcc | SrcImmUByte | No64, em_aad), 4686 F(DstAcc | ByteOp | No64, em_salc), 4687 I(DstAcc | SrcXLat | ByteOp, em_mov), 4688 /* 0xD8 - 0xDF */ 4689 N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, 4690 /* 0xE0 - 0xE7 */ 4691 X3(I(SrcImmByte | NearBranch | IsBranch, em_loop)), 4692 I(SrcImmByte | NearBranch | IsBranch, em_jcxz), 4693 I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in), 4694 I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out), 4695 /* 0xE8 - 0xEF */ 4696 I(SrcImm | NearBranch | IsBranch, em_call), 4697 D(SrcImm | ImplicitOps | NearBranch | IsBranch), 4698 I(SrcImmFAddr | No64 | IsBranch, em_jmp_far), 4699 D(SrcImmByte | ImplicitOps | NearBranch | IsBranch), 4700 I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in), 4701 I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out), 4702 /* 0xF0 - 0xF7 */ 4703 N, DI(ImplicitOps, icebp), N, N, 4704 DI(ImplicitOps | Priv, hlt), D(ImplicitOps), 4705 G(ByteOp, group3), G(0, group3), 4706 /* 0xF8 - 0xFF */ 4707 D(ImplicitOps), D(ImplicitOps), 4708 I(ImplicitOps, em_cli), I(ImplicitOps, em_sti), 4709 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5), 4710 }; 4711 4712 static const struct opcode twobyte_table[256] = { 4713 /* 0x00 - 0x0F */ 4714 G(0, group6), GD(0, &group7), N, N, 4715 N, I(ImplicitOps | EmulateOnUD | IsBranch, em_syscall), 4716 II(ImplicitOps | Priv, em_clts, clts), N, 4717 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N, 4718 N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N, 4719 /* 0x10 - 0x1F */ 4720 GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_10_0f_11), 4721 GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_10_0f_11), 4722 N, N, N, N, N, N, 4723 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 4 * prefetch + 4 * reserved NOP */ 4724 D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N, 4725 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */ 4726 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */ 4727 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */ 4728 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* NOP + 7 * reserved NOP */ 4729 /* 0x20 - 0x2F */ 4730 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_access), 4731 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read), 4732 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_cr_write, cr_write, 4733 check_cr_access), 4734 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_dr_write, dr_write, 4735 check_dr_write), 4736 N, N, N, N, 4737 GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_28_0f_29), 4738 GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_28_0f_29), 4739 N, GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_2b), 4740 N, N, N, N, 4741 /* 0x30 - 0x3F */ 4742 II(ImplicitOps | Priv, em_wrmsr, wrmsr), 4743 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc), 4744 II(ImplicitOps | Priv, em_rdmsr, rdmsr), 4745 IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc), 4746 I(ImplicitOps | EmulateOnUD | IsBranch, em_sysenter), 4747 I(ImplicitOps | Priv | EmulateOnUD | IsBranch, em_sysexit), 4748 N, N, 4749 N, N, N, N, N, N, N, N, 4750 /* 0x40 - 0x4F */ 4751 X16(D(DstReg | SrcMem | ModRM)), 4752 /* 0x50 - 0x5F */ 4753 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 4754 /* 0x60 - 0x6F */ 4755 N, N, N, N, 4756 N, N, N, N, 4757 N, N, N, N, 4758 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f), 4759 /* 0x70 - 0x7F */ 4760 N, N, N, N, 4761 N, N, N, N, 4762 N, N, N, N, 4763 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f), 4764 /* 0x80 - 0x8F */ 4765 X16(D(SrcImm | NearBranch | IsBranch)), 4766 /* 0x90 - 0x9F */ 4767 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)), 4768 /* 0xA0 - 0xA7 */ 4769 I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg), 4770 II(ImplicitOps, em_cpuid, cpuid), 4771 F(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt), 4772 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld), 4773 F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N, 4774 /* 0xA8 - 0xAF */ 4775 I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg), 4776 II(EmulateOnUD | ImplicitOps, em_rsm, rsm), 4777 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts), 4778 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd), 4779 F(DstMem | SrcReg | Src2CL | ModRM, em_shrd), 4780 GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul), 4781 /* 0xB0 - 0xB7 */ 4782 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable | SrcWrite, em_cmpxchg), 4783 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg), 4784 F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr), 4785 I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg), 4786 I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg), 4787 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), 4788 /* 0xB8 - 0xBF */ 4789 N, N, 4790 G(BitOp, group8), 4791 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc), 4792 I(DstReg | SrcMem | ModRM, em_bsf_c), 4793 I(DstReg | SrcMem | ModRM, em_bsr_c), 4794 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), 4795 /* 0xC0 - 0xC7 */ 4796 F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd), 4797 N, ID(0, &instr_dual_0f_c3), 4798 N, N, N, GD(0, &group9), 4799 /* 0xC8 - 0xCF */ 4800 X8(I(DstReg, em_bswap)), 4801 /* 0xD0 - 0xDF */ 4802 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 4803 /* 0xE0 - 0xEF */ 4804 N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_e7), 4805 N, N, N, N, N, N, N, N, 4806 /* 0xF0 - 0xFF */ 4807 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N 4808 }; 4809 4810 static const struct instr_dual instr_dual_0f_38_f0 = { 4811 I(DstReg | SrcMem | Mov, em_movbe), N 4812 }; 4813 4814 static const struct instr_dual instr_dual_0f_38_f1 = { 4815 I(DstMem | SrcReg | Mov, em_movbe), N 4816 }; 4817 4818 static const struct gprefix three_byte_0f_38_f0 = { 4819 ID(0, &instr_dual_0f_38_f0), N, N, N 4820 }; 4821 4822 static const struct gprefix three_byte_0f_38_f1 = { 4823 ID(0, &instr_dual_0f_38_f1), N, N, N 4824 }; 4825 4826 /* 4827 * Insns below are selected by the prefix which indexed by the third opcode 4828 * byte. 4829 */ 4830 static const struct opcode opcode_map_0f_38[256] = { 4831 /* 0x00 - 0x7f */ 4832 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), 4833 /* 0x80 - 0xef */ 4834 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), 4835 /* 0xf0 - 0xf1 */ 4836 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f0), 4837 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f1), 4838 /* 0xf2 - 0xff */ 4839 N, N, X4(N), X8(N) 4840 }; 4841 4842 #undef D 4843 #undef N 4844 #undef G 4845 #undef GD 4846 #undef I 4847 #undef GP 4848 #undef EXT 4849 #undef MD 4850 #undef ID 4851 4852 #undef D2bv 4853 #undef D2bvIP 4854 #undef I2bv 4855 #undef I2bvIP 4856 #undef I6ALU 4857 4858 static unsigned imm_size(struct x86_emulate_ctxt *ctxt) 4859 { 4860 unsigned size; 4861 4862 size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4863 if (size == 8) 4864 size = 4; 4865 return size; 4866 } 4867 4868 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op, 4869 unsigned size, bool sign_extension) 4870 { 4871 int rc = X86EMUL_CONTINUE; 4872 4873 op->type = OP_IMM; 4874 op->bytes = size; 4875 op->addr.mem.ea = ctxt->_eip; 4876 /* NB. Immediates are sign-extended as necessary. */ 4877 switch (op->bytes) { 4878 case 1: 4879 op->val = insn_fetch(s8, ctxt); 4880 break; 4881 case 2: 4882 op->val = insn_fetch(s16, ctxt); 4883 break; 4884 case 4: 4885 op->val = insn_fetch(s32, ctxt); 4886 break; 4887 case 8: 4888 op->val = insn_fetch(s64, ctxt); 4889 break; 4890 } 4891 if (!sign_extension) { 4892 switch (op->bytes) { 4893 case 1: 4894 op->val &= 0xff; 4895 break; 4896 case 2: 4897 op->val &= 0xffff; 4898 break; 4899 case 4: 4900 op->val &= 0xffffffff; 4901 break; 4902 } 4903 } 4904 done: 4905 return rc; 4906 } 4907 4908 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, 4909 unsigned d) 4910 { 4911 int rc = X86EMUL_CONTINUE; 4912 4913 switch (d) { 4914 case OpReg: 4915 decode_register_operand(ctxt, op); 4916 break; 4917 case OpImmUByte: 4918 rc = decode_imm(ctxt, op, 1, false); 4919 break; 4920 case OpMem: 4921 ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4922 mem_common: 4923 *op = ctxt->memop; 4924 ctxt->memopp = op; 4925 if (ctxt->d & BitOp) 4926 fetch_bit_operand(ctxt); 4927 op->orig_val = op->val; 4928 break; 4929 case OpMem64: 4930 ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8; 4931 goto mem_common; 4932 case OpAcc: 4933 op->type = OP_REG; 4934 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4935 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); 4936 fetch_register_operand(op); 4937 op->orig_val = op->val; 4938 break; 4939 case OpAccLo: 4940 op->type = OP_REG; 4941 op->bytes = (ctxt->d & ByteOp) ? 2 : ctxt->op_bytes; 4942 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); 4943 fetch_register_operand(op); 4944 op->orig_val = op->val; 4945 break; 4946 case OpAccHi: 4947 if (ctxt->d & ByteOp) { 4948 op->type = OP_NONE; 4949 break; 4950 } 4951 op->type = OP_REG; 4952 op->bytes = ctxt->op_bytes; 4953 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); 4954 fetch_register_operand(op); 4955 op->orig_val = op->val; 4956 break; 4957 case OpDI: 4958 op->type = OP_MEM; 4959 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4960 op->addr.mem.ea = 4961 register_address(ctxt, VCPU_REGS_RDI); 4962 op->addr.mem.seg = VCPU_SREG_ES; 4963 op->val = 0; 4964 op->count = 1; 4965 break; 4966 case OpDX: 4967 op->type = OP_REG; 4968 op->bytes = 2; 4969 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); 4970 fetch_register_operand(op); 4971 break; 4972 case OpCL: 4973 op->type = OP_IMM; 4974 op->bytes = 1; 4975 op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff; 4976 break; 4977 case OpImmByte: 4978 rc = decode_imm(ctxt, op, 1, true); 4979 break; 4980 case OpOne: 4981 op->type = OP_IMM; 4982 op->bytes = 1; 4983 op->val = 1; 4984 break; 4985 case OpImm: 4986 rc = decode_imm(ctxt, op, imm_size(ctxt), true); 4987 break; 4988 case OpImm64: 4989 rc = decode_imm(ctxt, op, ctxt->op_bytes, true); 4990 break; 4991 case OpMem8: 4992 ctxt->memop.bytes = 1; 4993 if (ctxt->memop.type == OP_REG) { 4994 ctxt->memop.addr.reg = decode_register(ctxt, 4995 ctxt->modrm_rm, true); 4996 fetch_register_operand(&ctxt->memop); 4997 } 4998 goto mem_common; 4999 case OpMem16: 5000 ctxt->memop.bytes = 2; 5001 goto mem_common; 5002 case OpMem32: 5003 ctxt->memop.bytes = 4; 5004 goto mem_common; 5005 case OpImmU16: 5006 rc = decode_imm(ctxt, op, 2, false); 5007 break; 5008 case OpImmU: 5009 rc = decode_imm(ctxt, op, imm_size(ctxt), false); 5010 break; 5011 case OpSI: 5012 op->type = OP_MEM; 5013 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 5014 op->addr.mem.ea = 5015 register_address(ctxt, VCPU_REGS_RSI); 5016 op->addr.mem.seg = ctxt->seg_override; 5017 op->val = 0; 5018 op->count = 1; 5019 break; 5020 case OpXLat: 5021 op->type = OP_MEM; 5022 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 5023 op->addr.mem.ea = 5024 address_mask(ctxt, 5025 reg_read(ctxt, VCPU_REGS_RBX) + 5026 (reg_read(ctxt, VCPU_REGS_RAX) & 0xff)); 5027 op->addr.mem.seg = ctxt->seg_override; 5028 op->val = 0; 5029 break; 5030 case OpImmFAddr: 5031 op->type = OP_IMM; 5032 op->addr.mem.ea = ctxt->_eip; 5033 op->bytes = ctxt->op_bytes + 2; 5034 insn_fetch_arr(op->valptr, op->bytes, ctxt); 5035 break; 5036 case OpMemFAddr: 5037 ctxt->memop.bytes = ctxt->op_bytes + 2; 5038 goto mem_common; 5039 case OpES: 5040 op->type = OP_IMM; 5041 op->val = VCPU_SREG_ES; 5042 break; 5043 case OpCS: 5044 op->type = OP_IMM; 5045 op->val = VCPU_SREG_CS; 5046 break; 5047 case OpSS: 5048 op->type = OP_IMM; 5049 op->val = VCPU_SREG_SS; 5050 break; 5051 case OpDS: 5052 op->type = OP_IMM; 5053 op->val = VCPU_SREG_DS; 5054 break; 5055 case OpFS: 5056 op->type = OP_IMM; 5057 op->val = VCPU_SREG_FS; 5058 break; 5059 case OpGS: 5060 op->type = OP_IMM; 5061 op->val = VCPU_SREG_GS; 5062 break; 5063 case OpImplicit: 5064 /* Special instructions do their own operand decoding. */ 5065 default: 5066 op->type = OP_NONE; /* Disable writeback. */ 5067 break; 5068 } 5069 5070 done: 5071 return rc; 5072 } 5073 5074 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int emulation_type) 5075 { 5076 int rc = X86EMUL_CONTINUE; 5077 int mode = ctxt->mode; 5078 int def_op_bytes, def_ad_bytes, goffset, simd_prefix; 5079 bool op_prefix = false; 5080 bool has_seg_override = false; 5081 struct opcode opcode; 5082 u16 dummy; 5083 struct desc_struct desc; 5084 5085 ctxt->memop.type = OP_NONE; 5086 ctxt->memopp = NULL; 5087 ctxt->_eip = ctxt->eip; 5088 ctxt->fetch.ptr = ctxt->fetch.data; 5089 ctxt->fetch.end = ctxt->fetch.data + insn_len; 5090 ctxt->opcode_len = 1; 5091 ctxt->intercept = x86_intercept_none; 5092 if (insn_len > 0) 5093 memcpy(ctxt->fetch.data, insn, insn_len); 5094 else { 5095 rc = __do_insn_fetch_bytes(ctxt, 1); 5096 if (rc != X86EMUL_CONTINUE) 5097 goto done; 5098 } 5099 5100 switch (mode) { 5101 case X86EMUL_MODE_REAL: 5102 case X86EMUL_MODE_VM86: 5103 def_op_bytes = def_ad_bytes = 2; 5104 ctxt->ops->get_segment(ctxt, &dummy, &desc, NULL, VCPU_SREG_CS); 5105 if (desc.d) 5106 def_op_bytes = def_ad_bytes = 4; 5107 break; 5108 case X86EMUL_MODE_PROT16: 5109 def_op_bytes = def_ad_bytes = 2; 5110 break; 5111 case X86EMUL_MODE_PROT32: 5112 def_op_bytes = def_ad_bytes = 4; 5113 break; 5114 #ifdef CONFIG_X86_64 5115 case X86EMUL_MODE_PROT64: 5116 def_op_bytes = 4; 5117 def_ad_bytes = 8; 5118 break; 5119 #endif 5120 default: 5121 return EMULATION_FAILED; 5122 } 5123 5124 ctxt->op_bytes = def_op_bytes; 5125 ctxt->ad_bytes = def_ad_bytes; 5126 5127 /* Legacy prefixes. */ 5128 for (;;) { 5129 switch (ctxt->b = insn_fetch(u8, ctxt)) { 5130 case 0x66: /* operand-size override */ 5131 op_prefix = true; 5132 /* switch between 2/4 bytes */ 5133 ctxt->op_bytes = def_op_bytes ^ 6; 5134 break; 5135 case 0x67: /* address-size override */ 5136 if (mode == X86EMUL_MODE_PROT64) 5137 /* switch between 4/8 bytes */ 5138 ctxt->ad_bytes = def_ad_bytes ^ 12; 5139 else 5140 /* switch between 2/4 bytes */ 5141 ctxt->ad_bytes = def_ad_bytes ^ 6; 5142 break; 5143 case 0x26: /* ES override */ 5144 has_seg_override = true; 5145 ctxt->seg_override = VCPU_SREG_ES; 5146 break; 5147 case 0x2e: /* CS override */ 5148 has_seg_override = true; 5149 ctxt->seg_override = VCPU_SREG_CS; 5150 break; 5151 case 0x36: /* SS override */ 5152 has_seg_override = true; 5153 ctxt->seg_override = VCPU_SREG_SS; 5154 break; 5155 case 0x3e: /* DS override */ 5156 has_seg_override = true; 5157 ctxt->seg_override = VCPU_SREG_DS; 5158 break; 5159 case 0x64: /* FS override */ 5160 has_seg_override = true; 5161 ctxt->seg_override = VCPU_SREG_FS; 5162 break; 5163 case 0x65: /* GS override */ 5164 has_seg_override = true; 5165 ctxt->seg_override = VCPU_SREG_GS; 5166 break; 5167 case 0x40 ... 0x4f: /* REX */ 5168 if (mode != X86EMUL_MODE_PROT64) 5169 goto done_prefixes; 5170 ctxt->rex_prefix = ctxt->b; 5171 continue; 5172 case 0xf0: /* LOCK */ 5173 ctxt->lock_prefix = 1; 5174 break; 5175 case 0xf2: /* REPNE/REPNZ */ 5176 case 0xf3: /* REP/REPE/REPZ */ 5177 ctxt->rep_prefix = ctxt->b; 5178 break; 5179 default: 5180 goto done_prefixes; 5181 } 5182 5183 /* Any legacy prefix after a REX prefix nullifies its effect. */ 5184 5185 ctxt->rex_prefix = 0; 5186 } 5187 5188 done_prefixes: 5189 5190 /* REX prefix. */ 5191 if (ctxt->rex_prefix & 8) 5192 ctxt->op_bytes = 8; /* REX.W */ 5193 5194 /* Opcode byte(s). */ 5195 opcode = opcode_table[ctxt->b]; 5196 /* Two-byte opcode? */ 5197 if (ctxt->b == 0x0f) { 5198 ctxt->opcode_len = 2; 5199 ctxt->b = insn_fetch(u8, ctxt); 5200 opcode = twobyte_table[ctxt->b]; 5201 5202 /* 0F_38 opcode map */ 5203 if (ctxt->b == 0x38) { 5204 ctxt->opcode_len = 3; 5205 ctxt->b = insn_fetch(u8, ctxt); 5206 opcode = opcode_map_0f_38[ctxt->b]; 5207 } 5208 } 5209 ctxt->d = opcode.flags; 5210 5211 if (ctxt->d & ModRM) 5212 ctxt->modrm = insn_fetch(u8, ctxt); 5213 5214 /* vex-prefix instructions are not implemented */ 5215 if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) && 5216 (mode == X86EMUL_MODE_PROT64 || (ctxt->modrm & 0xc0) == 0xc0)) { 5217 ctxt->d = NotImpl; 5218 } 5219 5220 while (ctxt->d & GroupMask) { 5221 switch (ctxt->d & GroupMask) { 5222 case Group: 5223 goffset = (ctxt->modrm >> 3) & 7; 5224 opcode = opcode.u.group[goffset]; 5225 break; 5226 case GroupDual: 5227 goffset = (ctxt->modrm >> 3) & 7; 5228 if ((ctxt->modrm >> 6) == 3) 5229 opcode = opcode.u.gdual->mod3[goffset]; 5230 else 5231 opcode = opcode.u.gdual->mod012[goffset]; 5232 break; 5233 case RMExt: 5234 goffset = ctxt->modrm & 7; 5235 opcode = opcode.u.group[goffset]; 5236 break; 5237 case Prefix: 5238 if (ctxt->rep_prefix && op_prefix) 5239 return EMULATION_FAILED; 5240 simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix; 5241 switch (simd_prefix) { 5242 case 0x00: opcode = opcode.u.gprefix->pfx_no; break; 5243 case 0x66: opcode = opcode.u.gprefix->pfx_66; break; 5244 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break; 5245 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break; 5246 } 5247 break; 5248 case Escape: 5249 if (ctxt->modrm > 0xbf) { 5250 size_t size = ARRAY_SIZE(opcode.u.esc->high); 5251 u32 index = array_index_nospec( 5252 ctxt->modrm - 0xc0, size); 5253 5254 opcode = opcode.u.esc->high[index]; 5255 } else { 5256 opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7]; 5257 } 5258 break; 5259 case InstrDual: 5260 if ((ctxt->modrm >> 6) == 3) 5261 opcode = opcode.u.idual->mod3; 5262 else 5263 opcode = opcode.u.idual->mod012; 5264 break; 5265 case ModeDual: 5266 if (ctxt->mode == X86EMUL_MODE_PROT64) 5267 opcode = opcode.u.mdual->mode64; 5268 else 5269 opcode = opcode.u.mdual->mode32; 5270 break; 5271 default: 5272 return EMULATION_FAILED; 5273 } 5274 5275 ctxt->d &= ~(u64)GroupMask; 5276 ctxt->d |= opcode.flags; 5277 } 5278 5279 ctxt->is_branch = opcode.flags & IsBranch; 5280 5281 /* Unrecognised? */ 5282 if (ctxt->d == 0) 5283 return EMULATION_FAILED; 5284 5285 ctxt->execute = opcode.u.execute; 5286 5287 if (unlikely(emulation_type & EMULTYPE_TRAP_UD) && 5288 likely(!(ctxt->d & EmulateOnUD))) 5289 return EMULATION_FAILED; 5290 5291 if (unlikely(ctxt->d & 5292 (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch| 5293 No16))) { 5294 /* 5295 * These are copied unconditionally here, and checked unconditionally 5296 * in x86_emulate_insn. 5297 */ 5298 ctxt->check_perm = opcode.check_perm; 5299 ctxt->intercept = opcode.intercept; 5300 5301 if (ctxt->d & NotImpl) 5302 return EMULATION_FAILED; 5303 5304 if (mode == X86EMUL_MODE_PROT64) { 5305 if (ctxt->op_bytes == 4 && (ctxt->d & Stack)) 5306 ctxt->op_bytes = 8; 5307 else if (ctxt->d & NearBranch) 5308 ctxt->op_bytes = 8; 5309 } 5310 5311 if (ctxt->d & Op3264) { 5312 if (mode == X86EMUL_MODE_PROT64) 5313 ctxt->op_bytes = 8; 5314 else 5315 ctxt->op_bytes = 4; 5316 } 5317 5318 if ((ctxt->d & No16) && ctxt->op_bytes == 2) 5319 ctxt->op_bytes = 4; 5320 5321 if (ctxt->d & Sse) 5322 ctxt->op_bytes = 16; 5323 else if (ctxt->d & Mmx) 5324 ctxt->op_bytes = 8; 5325 } 5326 5327 /* ModRM and SIB bytes. */ 5328 if (ctxt->d & ModRM) { 5329 rc = decode_modrm(ctxt, &ctxt->memop); 5330 if (!has_seg_override) { 5331 has_seg_override = true; 5332 ctxt->seg_override = ctxt->modrm_seg; 5333 } 5334 } else if (ctxt->d & MemAbs) 5335 rc = decode_abs(ctxt, &ctxt->memop); 5336 if (rc != X86EMUL_CONTINUE) 5337 goto done; 5338 5339 if (!has_seg_override) 5340 ctxt->seg_override = VCPU_SREG_DS; 5341 5342 ctxt->memop.addr.mem.seg = ctxt->seg_override; 5343 5344 /* 5345 * Decode and fetch the source operand: register, memory 5346 * or immediate. 5347 */ 5348 rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask); 5349 if (rc != X86EMUL_CONTINUE) 5350 goto done; 5351 5352 /* 5353 * Decode and fetch the second source operand: register, memory 5354 * or immediate. 5355 */ 5356 rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask); 5357 if (rc != X86EMUL_CONTINUE) 5358 goto done; 5359 5360 /* Decode and fetch the destination operand: register or memory. */ 5361 rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask); 5362 5363 if (ctxt->rip_relative && likely(ctxt->memopp)) 5364 ctxt->memopp->addr.mem.ea = address_mask(ctxt, 5365 ctxt->memopp->addr.mem.ea + ctxt->_eip); 5366 5367 done: 5368 if (rc == X86EMUL_PROPAGATE_FAULT) 5369 ctxt->have_exception = true; 5370 return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK; 5371 } 5372 5373 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt) 5374 { 5375 return ctxt->d & PageTable; 5376 } 5377 5378 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt) 5379 { 5380 /* The second termination condition only applies for REPE 5381 * and REPNE. Test if the repeat string operation prefix is 5382 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the 5383 * corresponding termination condition according to: 5384 * - if REPE/REPZ and ZF = 0 then done 5385 * - if REPNE/REPNZ and ZF = 1 then done 5386 */ 5387 if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) || 5388 (ctxt->b == 0xae) || (ctxt->b == 0xaf)) 5389 && (((ctxt->rep_prefix == REPE_PREFIX) && 5390 ((ctxt->eflags & X86_EFLAGS_ZF) == 0)) 5391 || ((ctxt->rep_prefix == REPNE_PREFIX) && 5392 ((ctxt->eflags & X86_EFLAGS_ZF) == X86_EFLAGS_ZF)))) 5393 return true; 5394 5395 return false; 5396 } 5397 5398 static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) 5399 { 5400 int rc; 5401 5402 kvm_fpu_get(); 5403 rc = asm_safe("fwait"); 5404 kvm_fpu_put(); 5405 5406 if (unlikely(rc != X86EMUL_CONTINUE)) 5407 return emulate_exception(ctxt, MF_VECTOR, 0, false); 5408 5409 return X86EMUL_CONTINUE; 5410 } 5411 5412 static void fetch_possible_mmx_operand(struct operand *op) 5413 { 5414 if (op->type == OP_MM) 5415 kvm_read_mmx_reg(op->addr.mm, &op->mm_val); 5416 } 5417 5418 static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop) 5419 { 5420 ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; 5421 5422 if (!(ctxt->d & ByteOp)) 5423 fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; 5424 5425 asm("push %[flags]; popf; " CALL_NOSPEC " ; pushf; pop %[flags]\n" 5426 : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags), 5427 [thunk_target]"+S"(fop), ASM_CALL_CONSTRAINT 5428 : "c"(ctxt->src2.val)); 5429 5430 ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); 5431 if (!fop) /* exception is returned in fop variable */ 5432 return emulate_de(ctxt); 5433 return X86EMUL_CONTINUE; 5434 } 5435 5436 void init_decode_cache(struct x86_emulate_ctxt *ctxt) 5437 { 5438 /* Clear fields that are set conditionally but read without a guard. */ 5439 ctxt->rip_relative = false; 5440 ctxt->rex_prefix = 0; 5441 ctxt->lock_prefix = 0; 5442 ctxt->rep_prefix = 0; 5443 ctxt->regs_valid = 0; 5444 ctxt->regs_dirty = 0; 5445 5446 ctxt->io_read.pos = 0; 5447 ctxt->io_read.end = 0; 5448 ctxt->mem_read.end = 0; 5449 } 5450 5451 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 5452 { 5453 const struct x86_emulate_ops *ops = ctxt->ops; 5454 int rc = X86EMUL_CONTINUE; 5455 int saved_dst_type = ctxt->dst.type; 5456 unsigned emul_flags; 5457 5458 ctxt->mem_read.pos = 0; 5459 5460 /* LOCK prefix is allowed only with some instructions */ 5461 if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) { 5462 rc = emulate_ud(ctxt); 5463 goto done; 5464 } 5465 5466 if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) { 5467 rc = emulate_ud(ctxt); 5468 goto done; 5469 } 5470 5471 emul_flags = ctxt->ops->get_hflags(ctxt); 5472 if (unlikely(ctxt->d & 5473 (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) { 5474 if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) || 5475 (ctxt->d & Undefined)) { 5476 rc = emulate_ud(ctxt); 5477 goto done; 5478 } 5479 5480 if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM))) 5481 || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) { 5482 rc = emulate_ud(ctxt); 5483 goto done; 5484 } 5485 5486 if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) { 5487 rc = emulate_nm(ctxt); 5488 goto done; 5489 } 5490 5491 if (ctxt->d & Mmx) { 5492 rc = flush_pending_x87_faults(ctxt); 5493 if (rc != X86EMUL_CONTINUE) 5494 goto done; 5495 /* 5496 * Now that we know the fpu is exception safe, we can fetch 5497 * operands from it. 5498 */ 5499 fetch_possible_mmx_operand(&ctxt->src); 5500 fetch_possible_mmx_operand(&ctxt->src2); 5501 if (!(ctxt->d & Mov)) 5502 fetch_possible_mmx_operand(&ctxt->dst); 5503 } 5504 5505 if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) { 5506 rc = emulator_check_intercept(ctxt, ctxt->intercept, 5507 X86_ICPT_PRE_EXCEPT); 5508 if (rc != X86EMUL_CONTINUE) 5509 goto done; 5510 } 5511 5512 /* Instruction can only be executed in protected mode */ 5513 if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) { 5514 rc = emulate_ud(ctxt); 5515 goto done; 5516 } 5517 5518 /* Privileged instruction can be executed only in CPL=0 */ 5519 if ((ctxt->d & Priv) && ops->cpl(ctxt)) { 5520 if (ctxt->d & PrivUD) 5521 rc = emulate_ud(ctxt); 5522 else 5523 rc = emulate_gp(ctxt, 0); 5524 goto done; 5525 } 5526 5527 /* Do instruction specific permission checks */ 5528 if (ctxt->d & CheckPerm) { 5529 rc = ctxt->check_perm(ctxt); 5530 if (rc != X86EMUL_CONTINUE) 5531 goto done; 5532 } 5533 5534 if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { 5535 rc = emulator_check_intercept(ctxt, ctxt->intercept, 5536 X86_ICPT_POST_EXCEPT); 5537 if (rc != X86EMUL_CONTINUE) 5538 goto done; 5539 } 5540 5541 if (ctxt->rep_prefix && (ctxt->d & String)) { 5542 /* All REP prefixes have the same first termination condition */ 5543 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) { 5544 string_registers_quirk(ctxt); 5545 ctxt->eip = ctxt->_eip; 5546 ctxt->eflags &= ~X86_EFLAGS_RF; 5547 goto done; 5548 } 5549 } 5550 } 5551 5552 if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) { 5553 rc = segmented_read(ctxt, ctxt->src.addr.mem, 5554 ctxt->src.valptr, ctxt->src.bytes); 5555 if (rc != X86EMUL_CONTINUE) 5556 goto done; 5557 ctxt->src.orig_val64 = ctxt->src.val64; 5558 } 5559 5560 if (ctxt->src2.type == OP_MEM) { 5561 rc = segmented_read(ctxt, ctxt->src2.addr.mem, 5562 &ctxt->src2.val, ctxt->src2.bytes); 5563 if (rc != X86EMUL_CONTINUE) 5564 goto done; 5565 } 5566 5567 if ((ctxt->d & DstMask) == ImplicitOps) 5568 goto special_insn; 5569 5570 5571 if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) { 5572 /* optimisation - avoid slow emulated read if Mov */ 5573 rc = segmented_read(ctxt, ctxt->dst.addr.mem, 5574 &ctxt->dst.val, ctxt->dst.bytes); 5575 if (rc != X86EMUL_CONTINUE) { 5576 if (!(ctxt->d & NoWrite) && 5577 rc == X86EMUL_PROPAGATE_FAULT && 5578 ctxt->exception.vector == PF_VECTOR) 5579 ctxt->exception.error_code |= PFERR_WRITE_MASK; 5580 goto done; 5581 } 5582 } 5583 /* Copy full 64-bit value for CMPXCHG8B. */ 5584 ctxt->dst.orig_val64 = ctxt->dst.val64; 5585 5586 special_insn: 5587 5588 if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { 5589 rc = emulator_check_intercept(ctxt, ctxt->intercept, 5590 X86_ICPT_POST_MEMACCESS); 5591 if (rc != X86EMUL_CONTINUE) 5592 goto done; 5593 } 5594 5595 if (ctxt->rep_prefix && (ctxt->d & String)) 5596 ctxt->eflags |= X86_EFLAGS_RF; 5597 else 5598 ctxt->eflags &= ~X86_EFLAGS_RF; 5599 5600 if (ctxt->execute) { 5601 if (ctxt->d & Fastop) 5602 rc = fastop(ctxt, ctxt->fop); 5603 else 5604 rc = ctxt->execute(ctxt); 5605 if (rc != X86EMUL_CONTINUE) 5606 goto done; 5607 goto writeback; 5608 } 5609 5610 if (ctxt->opcode_len == 2) 5611 goto twobyte_insn; 5612 else if (ctxt->opcode_len == 3) 5613 goto threebyte_insn; 5614 5615 switch (ctxt->b) { 5616 case 0x70 ... 0x7f: /* jcc (short) */ 5617 if (test_cc(ctxt->b, ctxt->eflags)) 5618 rc = jmp_rel(ctxt, ctxt->src.val); 5619 break; 5620 case 0x8d: /* lea r16/r32, m */ 5621 ctxt->dst.val = ctxt->src.addr.mem.ea; 5622 break; 5623 case 0x90 ... 0x97: /* nop / xchg reg, rax */ 5624 if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX)) 5625 ctxt->dst.type = OP_NONE; 5626 else 5627 rc = em_xchg(ctxt); 5628 break; 5629 case 0x98: /* cbw/cwde/cdqe */ 5630 switch (ctxt->op_bytes) { 5631 case 2: ctxt->dst.val = (s8)ctxt->dst.val; break; 5632 case 4: ctxt->dst.val = (s16)ctxt->dst.val; break; 5633 case 8: ctxt->dst.val = (s32)ctxt->dst.val; break; 5634 } 5635 break; 5636 case 0xcc: /* int3 */ 5637 rc = emulate_int(ctxt, 3); 5638 break; 5639 case 0xcd: /* int n */ 5640 rc = emulate_int(ctxt, ctxt->src.val); 5641 break; 5642 case 0xce: /* into */ 5643 if (ctxt->eflags & X86_EFLAGS_OF) 5644 rc = emulate_int(ctxt, 4); 5645 break; 5646 case 0xe9: /* jmp rel */ 5647 case 0xeb: /* jmp rel short */ 5648 rc = jmp_rel(ctxt, ctxt->src.val); 5649 ctxt->dst.type = OP_NONE; /* Disable writeback. */ 5650 break; 5651 case 0xf4: /* hlt */ 5652 ctxt->ops->halt(ctxt); 5653 break; 5654 case 0xf5: /* cmc */ 5655 /* complement carry flag from eflags reg */ 5656 ctxt->eflags ^= X86_EFLAGS_CF; 5657 break; 5658 case 0xf8: /* clc */ 5659 ctxt->eflags &= ~X86_EFLAGS_CF; 5660 break; 5661 case 0xf9: /* stc */ 5662 ctxt->eflags |= X86_EFLAGS_CF; 5663 break; 5664 case 0xfc: /* cld */ 5665 ctxt->eflags &= ~X86_EFLAGS_DF; 5666 break; 5667 case 0xfd: /* std */ 5668 ctxt->eflags |= X86_EFLAGS_DF; 5669 break; 5670 default: 5671 goto cannot_emulate; 5672 } 5673 5674 if (rc != X86EMUL_CONTINUE) 5675 goto done; 5676 5677 writeback: 5678 if (ctxt->d & SrcWrite) { 5679 BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR); 5680 rc = writeback(ctxt, &ctxt->src); 5681 if (rc != X86EMUL_CONTINUE) 5682 goto done; 5683 } 5684 if (!(ctxt->d & NoWrite)) { 5685 rc = writeback(ctxt, &ctxt->dst); 5686 if (rc != X86EMUL_CONTINUE) 5687 goto done; 5688 } 5689 5690 /* 5691 * restore dst type in case the decoding will be reused 5692 * (happens for string instruction ) 5693 */ 5694 ctxt->dst.type = saved_dst_type; 5695 5696 if ((ctxt->d & SrcMask) == SrcSI) 5697 string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src); 5698 5699 if ((ctxt->d & DstMask) == DstDI) 5700 string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst); 5701 5702 if (ctxt->rep_prefix && (ctxt->d & String)) { 5703 unsigned int count; 5704 struct read_cache *r = &ctxt->io_read; 5705 if ((ctxt->d & SrcMask) == SrcSI) 5706 count = ctxt->src.count; 5707 else 5708 count = ctxt->dst.count; 5709 register_address_increment(ctxt, VCPU_REGS_RCX, -count); 5710 5711 if (!string_insn_completed(ctxt)) { 5712 /* 5713 * Re-enter guest when pio read ahead buffer is empty 5714 * or, if it is not used, after each 1024 iteration. 5715 */ 5716 if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) && 5717 (r->end == 0 || r->end != r->pos)) { 5718 /* 5719 * Reset read cache. Usually happens before 5720 * decode, but since instruction is restarted 5721 * we have to do it here. 5722 */ 5723 ctxt->mem_read.end = 0; 5724 writeback_registers(ctxt); 5725 return EMULATION_RESTART; 5726 } 5727 goto done; /* skip rip writeback */ 5728 } 5729 ctxt->eflags &= ~X86_EFLAGS_RF; 5730 } 5731 5732 ctxt->eip = ctxt->_eip; 5733 if (ctxt->mode != X86EMUL_MODE_PROT64) 5734 ctxt->eip = (u32)ctxt->_eip; 5735 5736 done: 5737 if (rc == X86EMUL_PROPAGATE_FAULT) { 5738 if (KVM_EMULATOR_BUG_ON(ctxt->exception.vector > 0x1f, ctxt)) 5739 return EMULATION_FAILED; 5740 ctxt->have_exception = true; 5741 } 5742 if (rc == X86EMUL_INTERCEPTED) 5743 return EMULATION_INTERCEPTED; 5744 5745 if (rc == X86EMUL_CONTINUE) 5746 writeback_registers(ctxt); 5747 5748 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 5749 5750 twobyte_insn: 5751 switch (ctxt->b) { 5752 case 0x09: /* wbinvd */ 5753 (ctxt->ops->wbinvd)(ctxt); 5754 break; 5755 case 0x08: /* invd */ 5756 case 0x0d: /* GrpP (prefetch) */ 5757 case 0x18: /* Grp16 (prefetch/nop) */ 5758 case 0x1f: /* nop */ 5759 break; 5760 case 0x20: /* mov cr, reg */ 5761 ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg); 5762 break; 5763 case 0x21: /* mov from dr to reg */ 5764 ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val); 5765 break; 5766 case 0x40 ... 0x4f: /* cmov */ 5767 if (test_cc(ctxt->b, ctxt->eflags)) 5768 ctxt->dst.val = ctxt->src.val; 5769 else if (ctxt->op_bytes != 4) 5770 ctxt->dst.type = OP_NONE; /* no writeback */ 5771 break; 5772 case 0x80 ... 0x8f: /* jnz rel, etc*/ 5773 if (test_cc(ctxt->b, ctxt->eflags)) 5774 rc = jmp_rel(ctxt, ctxt->src.val); 5775 break; 5776 case 0x90 ... 0x9f: /* setcc r/m8 */ 5777 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags); 5778 break; 5779 case 0xb6 ... 0xb7: /* movzx */ 5780 ctxt->dst.bytes = ctxt->op_bytes; 5781 ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val 5782 : (u16) ctxt->src.val; 5783 break; 5784 case 0xbe ... 0xbf: /* movsx */ 5785 ctxt->dst.bytes = ctxt->op_bytes; 5786 ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val : 5787 (s16) ctxt->src.val; 5788 break; 5789 default: 5790 goto cannot_emulate; 5791 } 5792 5793 threebyte_insn: 5794 5795 if (rc != X86EMUL_CONTINUE) 5796 goto done; 5797 5798 goto writeback; 5799 5800 cannot_emulate: 5801 return EMULATION_FAILED; 5802 } 5803 5804 void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt) 5805 { 5806 invalidate_registers(ctxt); 5807 } 5808 5809 void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt) 5810 { 5811 writeback_registers(ctxt); 5812 } 5813 5814 bool emulator_can_use_gpa(struct x86_emulate_ctxt *ctxt) 5815 { 5816 if (ctxt->rep_prefix && (ctxt->d & String)) 5817 return false; 5818 5819 if (ctxt->d & TwoMemOp) 5820 return false; 5821 5822 return true; 5823 } 5824