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 28 #include "x86.h" 29 #include "tss.h" 30 #include "mmu.h" 31 #include "pmu.h" 32 33 /* 34 * Operand types 35 */ 36 #define OpNone 0ull 37 #define OpImplicit 1ull /* No generic decode */ 38 #define OpReg 2ull /* Register */ 39 #define OpMem 3ull /* Memory */ 40 #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */ 41 #define OpDI 5ull /* ES:DI/EDI/RDI */ 42 #define OpMem64 6ull /* Memory, 64-bit */ 43 #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */ 44 #define OpDX 8ull /* DX register */ 45 #define OpCL 9ull /* CL register (for shifts) */ 46 #define OpImmByte 10ull /* 8-bit sign extended immediate */ 47 #define OpOne 11ull /* Implied 1 */ 48 #define OpImm 12ull /* Sign extended up to 32-bit immediate */ 49 #define OpMem16 13ull /* Memory operand (16-bit). */ 50 #define OpMem32 14ull /* Memory operand (32-bit). */ 51 #define OpImmU 15ull /* Immediate operand, zero extended */ 52 #define OpSI 16ull /* SI/ESI/RSI */ 53 #define OpImmFAddr 17ull /* Immediate far address */ 54 #define OpMemFAddr 18ull /* Far address in memory */ 55 #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */ 56 #define OpES 20ull /* ES */ 57 #define OpCS 21ull /* CS */ 58 #define OpSS 22ull /* SS */ 59 #define OpDS 23ull /* DS */ 60 #define OpFS 24ull /* FS */ 61 #define OpGS 25ull /* GS */ 62 #define OpMem8 26ull /* 8-bit zero extended memory operand */ 63 #define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */ 64 #define OpXLat 28ull /* memory at BX/EBX/RBX + zero-extended AL */ 65 #define OpAccLo 29ull /* Low part of extended acc (AX/AX/EAX/RAX) */ 66 #define OpAccHi 30ull /* High part of extended acc (-/DX/EDX/RDX) */ 67 68 #define OpBits 5 /* Width of operand field */ 69 #define OpMask ((1ull << OpBits) - 1) 70 71 /* 72 * Opcode effective-address decode tables. 73 * Note that we only emulate instructions that have at least one memory 74 * operand (excluding implicit stack references). We assume that stack 75 * references and instruction fetches will never occur in special memory 76 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need 77 * not be handled. 78 */ 79 80 /* Operand sizes: 8-bit operands or specified/overridden size. */ 81 #define ByteOp (1<<0) /* 8-bit operands. */ 82 /* Destination operand type. */ 83 #define DstShift 1 84 #define ImplicitOps (OpImplicit << DstShift) 85 #define DstReg (OpReg << DstShift) 86 #define DstMem (OpMem << DstShift) 87 #define DstAcc (OpAcc << DstShift) 88 #define DstDI (OpDI << DstShift) 89 #define DstMem64 (OpMem64 << DstShift) 90 #define DstMem16 (OpMem16 << DstShift) 91 #define DstImmUByte (OpImmUByte << DstShift) 92 #define DstDX (OpDX << DstShift) 93 #define DstAccLo (OpAccLo << DstShift) 94 #define DstMask (OpMask << DstShift) 95 /* Source operand type. */ 96 #define SrcShift 6 97 #define SrcNone (OpNone << SrcShift) 98 #define SrcReg (OpReg << SrcShift) 99 #define SrcMem (OpMem << SrcShift) 100 #define SrcMem16 (OpMem16 << SrcShift) 101 #define SrcMem32 (OpMem32 << SrcShift) 102 #define SrcImm (OpImm << SrcShift) 103 #define SrcImmByte (OpImmByte << SrcShift) 104 #define SrcOne (OpOne << SrcShift) 105 #define SrcImmUByte (OpImmUByte << SrcShift) 106 #define SrcImmU (OpImmU << SrcShift) 107 #define SrcSI (OpSI << SrcShift) 108 #define SrcXLat (OpXLat << SrcShift) 109 #define SrcImmFAddr (OpImmFAddr << SrcShift) 110 #define SrcMemFAddr (OpMemFAddr << SrcShift) 111 #define SrcAcc (OpAcc << SrcShift) 112 #define SrcImmU16 (OpImmU16 << SrcShift) 113 #define SrcImm64 (OpImm64 << SrcShift) 114 #define SrcDX (OpDX << SrcShift) 115 #define SrcMem8 (OpMem8 << SrcShift) 116 #define SrcAccHi (OpAccHi << SrcShift) 117 #define SrcMask (OpMask << SrcShift) 118 #define BitOp (1<<11) 119 #define MemAbs (1<<12) /* Memory operand is absolute displacement */ 120 #define String (1<<13) /* String instruction (rep capable) */ 121 #define Stack (1<<14) /* Stack instruction (push/pop) */ 122 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */ 123 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */ 124 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */ 125 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */ 126 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */ 127 #define Escape (5<<15) /* Escape to coprocessor instruction */ 128 #define InstrDual (6<<15) /* Alternate instruction decoding of mod == 3 */ 129 #define ModeDual (7<<15) /* Different instruction for 32/64 bit */ 130 #define Sse (1<<18) /* SSE Vector instruction */ 131 /* Generic ModRM decode. */ 132 #define ModRM (1<<19) 133 /* Destination is only written; never read. */ 134 #define Mov (1<<20) 135 /* Misc flags */ 136 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */ 137 #define EmulateOnUD (1<<22) /* Emulate if unsupported by the host */ 138 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */ 139 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */ 140 #define Undefined (1<<25) /* No Such Instruction */ 141 #define Lock (1<<26) /* lock prefix is allowed for the instruction */ 142 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ 143 #define No64 (1<<28) 144 #define PageTable (1 << 29) /* instruction used to write page table */ 145 #define NotImpl (1 << 30) /* instruction is not implemented */ 146 /* Source 2 operand type */ 147 #define Src2Shift (31) 148 #define Src2None (OpNone << Src2Shift) 149 #define Src2Mem (OpMem << Src2Shift) 150 #define Src2CL (OpCL << Src2Shift) 151 #define Src2ImmByte (OpImmByte << Src2Shift) 152 #define Src2One (OpOne << Src2Shift) 153 #define Src2Imm (OpImm << Src2Shift) 154 #define Src2ES (OpES << Src2Shift) 155 #define Src2CS (OpCS << Src2Shift) 156 #define Src2SS (OpSS << Src2Shift) 157 #define Src2DS (OpDS << Src2Shift) 158 #define Src2FS (OpFS << Src2Shift) 159 #define Src2GS (OpGS << Src2Shift) 160 #define Src2Mask (OpMask << Src2Shift) 161 #define Mmx ((u64)1 << 40) /* MMX Vector instruction */ 162 #define AlignMask ((u64)7 << 41) 163 #define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */ 164 #define Unaligned ((u64)2 << 41) /* Explicitly unaligned (e.g. MOVDQU) */ 165 #define Avx ((u64)3 << 41) /* Advanced Vector Extensions */ 166 #define Aligned16 ((u64)4 << 41) /* Aligned to 16 byte boundary (e.g. FXSAVE) */ 167 #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */ 168 #define NoWrite ((u64)1 << 45) /* No writeback */ 169 #define SrcWrite ((u64)1 << 46) /* Write back src operand */ 170 #define NoMod ((u64)1 << 47) /* Mod field is ignored */ 171 #define Intercept ((u64)1 << 48) /* Has valid intercept field */ 172 #define CheckPerm ((u64)1 << 49) /* Has valid check_perm field */ 173 #define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */ 174 #define NearBranch ((u64)1 << 52) /* Near branches */ 175 #define No16 ((u64)1 << 53) /* No 16 bit operand */ 176 #define IncSP ((u64)1 << 54) /* SP is incremented before ModRM calc */ 177 #define TwoMemOp ((u64)1 << 55) /* Instruction has two memory operand */ 178 179 #define DstXacc (DstAccLo | SrcAccHi | SrcWrite) 180 181 #define X2(x...) x, x 182 #define X3(x...) X2(x), x 183 #define X4(x...) X2(x), X2(x) 184 #define X5(x...) X4(x), x 185 #define X6(x...) X4(x), X2(x) 186 #define X7(x...) X4(x), X3(x) 187 #define X8(x...) X4(x), X4(x) 188 #define X16(x...) X8(x), X8(x) 189 190 #define NR_FASTOP (ilog2(sizeof(ulong)) + 1) 191 #define FASTOP_SIZE 8 192 193 struct opcode { 194 u64 flags : 56; 195 u64 intercept : 8; 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 (!(ctxt->regs_valid & (1 << nr))) { 248 ctxt->regs_valid |= 1 << nr; 249 ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr); 250 } 251 return ctxt->_regs[nr]; 252 } 253 254 static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr) 255 { 256 ctxt->regs_valid |= 1 << nr; 257 ctxt->regs_dirty |= 1 << nr; 258 return &ctxt->_regs[nr]; 259 } 260 261 static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr) 262 { 263 reg_read(ctxt, nr); 264 return reg_write(ctxt, nr); 265 } 266 267 static void writeback_registers(struct x86_emulate_ctxt *ctxt) 268 { 269 unsigned reg; 270 271 for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16) 272 ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]); 273 } 274 275 static void invalidate_registers(struct x86_emulate_ctxt *ctxt) 276 { 277 ctxt->regs_dirty = 0; 278 ctxt->regs_valid = 0; 279 } 280 281 /* 282 * These EFLAGS bits are restored from saved value during emulation, and 283 * any changes are written back to the saved value after emulation. 284 */ 285 #define EFLAGS_MASK (X86_EFLAGS_OF|X86_EFLAGS_SF|X86_EFLAGS_ZF|X86_EFLAGS_AF|\ 286 X86_EFLAGS_PF|X86_EFLAGS_CF) 287 288 #ifdef CONFIG_X86_64 289 #define ON64(x) x 290 #else 291 #define ON64(x) 292 #endif 293 294 /* 295 * fastop functions have a special calling convention: 296 * 297 * dst: rax (in/out) 298 * src: rdx (in/out) 299 * src2: rcx (in) 300 * flags: rflags (in/out) 301 * ex: rsi (in:fastop pointer, out:zero if exception) 302 * 303 * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for 304 * different operand sizes can be reached by calculation, rather than a jump 305 * table (which would be bigger than the code). 306 */ 307 static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop); 308 309 #define __FOP_FUNC(name) \ 310 ".align " __stringify(FASTOP_SIZE) " \n\t" \ 311 ".type " name ", @function \n\t" \ 312 name ":\n\t" 313 314 #define FOP_FUNC(name) \ 315 __FOP_FUNC(#name) 316 317 #define __FOP_RET(name) \ 318 "ret \n\t" \ 319 ".size " name ", .-" name "\n\t" 320 321 #define FOP_RET(name) \ 322 __FOP_RET(#name) 323 324 #define FOP_START(op) \ 325 extern void em_##op(struct fastop *fake); \ 326 asm(".pushsection .text, \"ax\" \n\t" \ 327 ".global em_" #op " \n\t" \ 328 ".align " __stringify(FASTOP_SIZE) " \n\t" \ 329 "em_" #op ":\n\t" 330 331 #define FOP_END \ 332 ".popsection") 333 334 #define __FOPNOP(name) \ 335 __FOP_FUNC(name) \ 336 __FOP_RET(name) 337 338 #define FOPNOP() \ 339 __FOPNOP(__stringify(__UNIQUE_ID(nop))) 340 341 #define FOP1E(op, dst) \ 342 __FOP_FUNC(#op "_" #dst) \ 343 "10: " #op " %" #dst " \n\t" \ 344 __FOP_RET(#op "_" #dst) 345 346 #define FOP1EEX(op, dst) \ 347 FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception) 348 349 #define FASTOP1(op) \ 350 FOP_START(op) \ 351 FOP1E(op##b, al) \ 352 FOP1E(op##w, ax) \ 353 FOP1E(op##l, eax) \ 354 ON64(FOP1E(op##q, rax)) \ 355 FOP_END 356 357 /* 1-operand, using src2 (for MUL/DIV r/m) */ 358 #define FASTOP1SRC2(op, name) \ 359 FOP_START(name) \ 360 FOP1E(op, cl) \ 361 FOP1E(op, cx) \ 362 FOP1E(op, ecx) \ 363 ON64(FOP1E(op, rcx)) \ 364 FOP_END 365 366 /* 1-operand, using src2 (for MUL/DIV r/m), with exceptions */ 367 #define FASTOP1SRC2EX(op, name) \ 368 FOP_START(name) \ 369 FOP1EEX(op, cl) \ 370 FOP1EEX(op, cx) \ 371 FOP1EEX(op, ecx) \ 372 ON64(FOP1EEX(op, rcx)) \ 373 FOP_END 374 375 #define FOP2E(op, dst, src) \ 376 __FOP_FUNC(#op "_" #dst "_" #src) \ 377 #op " %" #src ", %" #dst " \n\t" \ 378 __FOP_RET(#op "_" #dst "_" #src) 379 380 #define FASTOP2(op) \ 381 FOP_START(op) \ 382 FOP2E(op##b, al, dl) \ 383 FOP2E(op##w, ax, dx) \ 384 FOP2E(op##l, eax, edx) \ 385 ON64(FOP2E(op##q, rax, rdx)) \ 386 FOP_END 387 388 /* 2 operand, word only */ 389 #define FASTOP2W(op) \ 390 FOP_START(op) \ 391 FOPNOP() \ 392 FOP2E(op##w, ax, dx) \ 393 FOP2E(op##l, eax, edx) \ 394 ON64(FOP2E(op##q, rax, rdx)) \ 395 FOP_END 396 397 /* 2 operand, src is CL */ 398 #define FASTOP2CL(op) \ 399 FOP_START(op) \ 400 FOP2E(op##b, al, cl) \ 401 FOP2E(op##w, ax, cl) \ 402 FOP2E(op##l, eax, cl) \ 403 ON64(FOP2E(op##q, rax, cl)) \ 404 FOP_END 405 406 /* 2 operand, src and dest are reversed */ 407 #define FASTOP2R(op, name) \ 408 FOP_START(name) \ 409 FOP2E(op##b, dl, al) \ 410 FOP2E(op##w, dx, ax) \ 411 FOP2E(op##l, edx, eax) \ 412 ON64(FOP2E(op##q, rdx, rax)) \ 413 FOP_END 414 415 #define FOP3E(op, dst, src, src2) \ 416 __FOP_FUNC(#op "_" #dst "_" #src "_" #src2) \ 417 #op " %" #src2 ", %" #src ", %" #dst " \n\t"\ 418 __FOP_RET(#op "_" #dst "_" #src "_" #src2) 419 420 /* 3-operand, word-only, src2=cl */ 421 #define FASTOP3WCL(op) \ 422 FOP_START(op) \ 423 FOPNOP() \ 424 FOP3E(op##w, ax, dx, cl) \ 425 FOP3E(op##l, eax, edx, cl) \ 426 ON64(FOP3E(op##q, rax, rdx, cl)) \ 427 FOP_END 428 429 /* Special case for SETcc - 1 instruction per cc */ 430 #define FOP_SETCC(op) \ 431 ".align 4 \n\t" \ 432 ".type " #op ", @function \n\t" \ 433 #op ": \n\t" \ 434 #op " %al \n\t" \ 435 __FOP_RET(#op) 436 437 asm(".pushsection .fixup, \"ax\"\n" 438 ".global kvm_fastop_exception \n" 439 "kvm_fastop_exception: xor %esi, %esi; ret\n" 440 ".popsection"); 441 442 FOP_START(setcc) 443 FOP_SETCC(seto) 444 FOP_SETCC(setno) 445 FOP_SETCC(setc) 446 FOP_SETCC(setnc) 447 FOP_SETCC(setz) 448 FOP_SETCC(setnz) 449 FOP_SETCC(setbe) 450 FOP_SETCC(setnbe) 451 FOP_SETCC(sets) 452 FOP_SETCC(setns) 453 FOP_SETCC(setp) 454 FOP_SETCC(setnp) 455 FOP_SETCC(setl) 456 FOP_SETCC(setnl) 457 FOP_SETCC(setle) 458 FOP_SETCC(setnle) 459 FOP_END; 460 461 FOP_START(salc) 462 FOP_FUNC(salc) 463 "pushf; sbb %al, %al; popf \n\t" 464 FOP_RET(salc) 465 FOP_END; 466 467 /* 468 * XXX: inoutclob user must know where the argument is being expanded. 469 * Relying on CONFIG_CC_HAS_ASM_GOTO would allow us to remove _fault. 470 */ 471 #define asm_safe(insn, inoutclob...) \ 472 ({ \ 473 int _fault = 0; \ 474 \ 475 asm volatile("1:" insn "\n" \ 476 "2:\n" \ 477 ".pushsection .fixup, \"ax\"\n" \ 478 "3: movl $1, %[_fault]\n" \ 479 " jmp 2b\n" \ 480 ".popsection\n" \ 481 _ASM_EXTABLE(1b, 3b) \ 482 : [_fault] "+qm"(_fault) inoutclob ); \ 483 \ 484 _fault ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; \ 485 }) 486 487 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt, 488 enum x86_intercept intercept, 489 enum x86_intercept_stage stage) 490 { 491 struct x86_instruction_info info = { 492 .intercept = intercept, 493 .rep_prefix = ctxt->rep_prefix, 494 .modrm_mod = ctxt->modrm_mod, 495 .modrm_reg = ctxt->modrm_reg, 496 .modrm_rm = ctxt->modrm_rm, 497 .src_val = ctxt->src.val64, 498 .dst_val = ctxt->dst.val64, 499 .src_bytes = ctxt->src.bytes, 500 .dst_bytes = ctxt->dst.bytes, 501 .ad_bytes = ctxt->ad_bytes, 502 .next_rip = ctxt->eip, 503 }; 504 505 return ctxt->ops->intercept(ctxt, &info, stage); 506 } 507 508 static void assign_masked(ulong *dest, ulong src, ulong mask) 509 { 510 *dest = (*dest & ~mask) | (src & mask); 511 } 512 513 static void assign_register(unsigned long *reg, u64 val, int bytes) 514 { 515 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */ 516 switch (bytes) { 517 case 1: 518 *(u8 *)reg = (u8)val; 519 break; 520 case 2: 521 *(u16 *)reg = (u16)val; 522 break; 523 case 4: 524 *reg = (u32)val; 525 break; /* 64b: zero-extend */ 526 case 8: 527 *reg = val; 528 break; 529 } 530 } 531 532 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt) 533 { 534 return (1UL << (ctxt->ad_bytes << 3)) - 1; 535 } 536 537 static ulong stack_mask(struct x86_emulate_ctxt *ctxt) 538 { 539 u16 sel; 540 struct desc_struct ss; 541 542 if (ctxt->mode == X86EMUL_MODE_PROT64) 543 return ~0UL; 544 ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS); 545 return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */ 546 } 547 548 static int stack_size(struct x86_emulate_ctxt *ctxt) 549 { 550 return (__fls(stack_mask(ctxt)) + 1) >> 3; 551 } 552 553 /* Access/update address held in a register, based on addressing mode. */ 554 static inline unsigned long 555 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg) 556 { 557 if (ctxt->ad_bytes == sizeof(unsigned long)) 558 return reg; 559 else 560 return reg & ad_mask(ctxt); 561 } 562 563 static inline unsigned long 564 register_address(struct x86_emulate_ctxt *ctxt, int reg) 565 { 566 return address_mask(ctxt, reg_read(ctxt, reg)); 567 } 568 569 static void masked_increment(ulong *reg, ulong mask, int inc) 570 { 571 assign_masked(reg, *reg + inc, mask); 572 } 573 574 static inline void 575 register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc) 576 { 577 ulong *preg = reg_rmw(ctxt, reg); 578 579 assign_register(preg, *preg + inc, ctxt->ad_bytes); 580 } 581 582 static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc) 583 { 584 masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc); 585 } 586 587 static u32 desc_limit_scaled(struct desc_struct *desc) 588 { 589 u32 limit = get_desc_limit(desc); 590 591 return desc->g ? (limit << 12) | 0xfff : limit; 592 } 593 594 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg) 595 { 596 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) 597 return 0; 598 599 return ctxt->ops->get_cached_segment_base(ctxt, seg); 600 } 601 602 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, 603 u32 error, bool valid) 604 { 605 WARN_ON(vec > 0x1f); 606 ctxt->exception.vector = vec; 607 ctxt->exception.error_code = error; 608 ctxt->exception.error_code_valid = valid; 609 return X86EMUL_PROPAGATE_FAULT; 610 } 611 612 static int emulate_db(struct x86_emulate_ctxt *ctxt) 613 { 614 return emulate_exception(ctxt, DB_VECTOR, 0, false); 615 } 616 617 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) 618 { 619 return emulate_exception(ctxt, GP_VECTOR, err, true); 620 } 621 622 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err) 623 { 624 return emulate_exception(ctxt, SS_VECTOR, err, true); 625 } 626 627 static int emulate_ud(struct x86_emulate_ctxt *ctxt) 628 { 629 return emulate_exception(ctxt, UD_VECTOR, 0, false); 630 } 631 632 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err) 633 { 634 return emulate_exception(ctxt, TS_VECTOR, err, true); 635 } 636 637 static int emulate_de(struct x86_emulate_ctxt *ctxt) 638 { 639 return emulate_exception(ctxt, DE_VECTOR, 0, false); 640 } 641 642 static int emulate_nm(struct x86_emulate_ctxt *ctxt) 643 { 644 return emulate_exception(ctxt, NM_VECTOR, 0, false); 645 } 646 647 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg) 648 { 649 u16 selector; 650 struct desc_struct desc; 651 652 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg); 653 return selector; 654 } 655 656 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector, 657 unsigned seg) 658 { 659 u16 dummy; 660 u32 base3; 661 struct desc_struct desc; 662 663 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg); 664 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg); 665 } 666 667 static inline u8 ctxt_virt_addr_bits(struct x86_emulate_ctxt *ctxt) 668 { 669 return (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_LA57) ? 57 : 48; 670 } 671 672 static inline bool emul_is_noncanonical_address(u64 la, 673 struct x86_emulate_ctxt *ctxt) 674 { 675 return get_canonical(la, ctxt_virt_addr_bits(ctxt)) != la; 676 } 677 678 /* 679 * x86 defines three classes of vector instructions: explicitly 680 * aligned, explicitly unaligned, and the rest, which change behaviour 681 * depending on whether they're AVX encoded or not. 682 * 683 * Also included is CMPXCHG16B which is not a vector instruction, yet it is 684 * subject to the same check. FXSAVE and FXRSTOR are checked here too as their 685 * 512 bytes of data must be aligned to a 16 byte boundary. 686 */ 687 static unsigned insn_alignment(struct x86_emulate_ctxt *ctxt, unsigned size) 688 { 689 u64 alignment = ctxt->d & AlignMask; 690 691 if (likely(size < 16)) 692 return 1; 693 694 switch (alignment) { 695 case Unaligned: 696 case Avx: 697 return 1; 698 case Aligned16: 699 return 16; 700 case Aligned: 701 default: 702 return size; 703 } 704 } 705 706 static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt, 707 struct segmented_address addr, 708 unsigned *max_size, unsigned size, 709 bool write, bool fetch, 710 enum x86emul_mode mode, ulong *linear) 711 { 712 struct desc_struct desc; 713 bool usable; 714 ulong la; 715 u32 lim; 716 u16 sel; 717 u8 va_bits; 718 719 la = seg_base(ctxt, addr.seg) + addr.ea; 720 *max_size = 0; 721 switch (mode) { 722 case X86EMUL_MODE_PROT64: 723 *linear = la; 724 va_bits = ctxt_virt_addr_bits(ctxt); 725 if (get_canonical(la, va_bits) != la) 726 goto bad; 727 728 *max_size = min_t(u64, ~0u, (1ull << va_bits) - la); 729 if (size > *max_size) 730 goto bad; 731 break; 732 default: 733 *linear = la = (u32)la; 734 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL, 735 addr.seg); 736 if (!usable) 737 goto bad; 738 /* code segment in protected mode or read-only data segment */ 739 if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8)) 740 || !(desc.type & 2)) && write) 741 goto bad; 742 /* unreadable code segment */ 743 if (!fetch && (desc.type & 8) && !(desc.type & 2)) 744 goto bad; 745 lim = desc_limit_scaled(&desc); 746 if (!(desc.type & 8) && (desc.type & 4)) { 747 /* expand-down segment */ 748 if (addr.ea <= lim) 749 goto bad; 750 lim = desc.d ? 0xffffffff : 0xffff; 751 } 752 if (addr.ea > lim) 753 goto bad; 754 if (lim == 0xffffffff) 755 *max_size = ~0u; 756 else { 757 *max_size = (u64)lim + 1 - addr.ea; 758 if (size > *max_size) 759 goto bad; 760 } 761 break; 762 } 763 if (la & (insn_alignment(ctxt, size) - 1)) 764 return emulate_gp(ctxt, 0); 765 return X86EMUL_CONTINUE; 766 bad: 767 if (addr.seg == VCPU_SREG_SS) 768 return emulate_ss(ctxt, 0); 769 else 770 return emulate_gp(ctxt, 0); 771 } 772 773 static int linearize(struct x86_emulate_ctxt *ctxt, 774 struct segmented_address addr, 775 unsigned size, bool write, 776 ulong *linear) 777 { 778 unsigned max_size; 779 return __linearize(ctxt, addr, &max_size, size, write, false, 780 ctxt->mode, linear); 781 } 782 783 static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst, 784 enum x86emul_mode mode) 785 { 786 ulong linear; 787 int rc; 788 unsigned max_size; 789 struct segmented_address addr = { .seg = VCPU_SREG_CS, 790 .ea = dst }; 791 792 if (ctxt->op_bytes != sizeof(unsigned long)) 793 addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1); 794 rc = __linearize(ctxt, addr, &max_size, 1, false, true, mode, &linear); 795 if (rc == X86EMUL_CONTINUE) 796 ctxt->_eip = addr.ea; 797 return rc; 798 } 799 800 static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst) 801 { 802 return assign_eip(ctxt, dst, ctxt->mode); 803 } 804 805 static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst, 806 const struct desc_struct *cs_desc) 807 { 808 enum x86emul_mode mode = ctxt->mode; 809 int rc; 810 811 #ifdef CONFIG_X86_64 812 if (ctxt->mode >= X86EMUL_MODE_PROT16) { 813 if (cs_desc->l) { 814 u64 efer = 0; 815 816 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 817 if (efer & EFER_LMA) 818 mode = X86EMUL_MODE_PROT64; 819 } else 820 mode = X86EMUL_MODE_PROT32; /* temporary value */ 821 } 822 #endif 823 if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32) 824 mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16; 825 rc = assign_eip(ctxt, dst, mode); 826 if (rc == X86EMUL_CONTINUE) 827 ctxt->mode = mode; 828 return rc; 829 } 830 831 static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel) 832 { 833 return assign_eip_near(ctxt, ctxt->_eip + rel); 834 } 835 836 static int linear_read_system(struct x86_emulate_ctxt *ctxt, ulong linear, 837 void *data, unsigned size) 838 { 839 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, true); 840 } 841 842 static int linear_write_system(struct x86_emulate_ctxt *ctxt, 843 ulong linear, void *data, 844 unsigned int size) 845 { 846 return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, true); 847 } 848 849 static int segmented_read_std(struct x86_emulate_ctxt *ctxt, 850 struct segmented_address addr, 851 void *data, 852 unsigned size) 853 { 854 int rc; 855 ulong linear; 856 857 rc = linearize(ctxt, addr, size, false, &linear); 858 if (rc != X86EMUL_CONTINUE) 859 return rc; 860 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception, false); 861 } 862 863 static int segmented_write_std(struct x86_emulate_ctxt *ctxt, 864 struct segmented_address addr, 865 void *data, 866 unsigned int size) 867 { 868 int rc; 869 ulong linear; 870 871 rc = linearize(ctxt, addr, size, true, &linear); 872 if (rc != X86EMUL_CONTINUE) 873 return rc; 874 return ctxt->ops->write_std(ctxt, linear, data, size, &ctxt->exception, false); 875 } 876 877 /* 878 * Prefetch the remaining bytes of the instruction without crossing page 879 * boundary if they are not in fetch_cache yet. 880 */ 881 static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size) 882 { 883 int rc; 884 unsigned size, max_size; 885 unsigned long linear; 886 int cur_size = ctxt->fetch.end - ctxt->fetch.data; 887 struct segmented_address addr = { .seg = VCPU_SREG_CS, 888 .ea = ctxt->eip + cur_size }; 889 890 /* 891 * We do not know exactly how many bytes will be needed, and 892 * __linearize is expensive, so fetch as much as possible. We 893 * just have to avoid going beyond the 15 byte limit, the end 894 * of the segment, or the end of the page. 895 * 896 * __linearize is called with size 0 so that it does not do any 897 * boundary check itself. Instead, we use max_size to check 898 * against op_size. 899 */ 900 rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode, 901 &linear); 902 if (unlikely(rc != X86EMUL_CONTINUE)) 903 return rc; 904 905 size = min_t(unsigned, 15UL ^ cur_size, max_size); 906 size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear)); 907 908 /* 909 * One instruction can only straddle two pages, 910 * and one has been loaded at the beginning of 911 * x86_decode_insn. So, if not enough bytes 912 * still, we must have hit the 15-byte boundary. 913 */ 914 if (unlikely(size < op_size)) 915 return emulate_gp(ctxt, 0); 916 917 rc = ctxt->ops->fetch(ctxt, linear, ctxt->fetch.end, 918 size, &ctxt->exception); 919 if (unlikely(rc != X86EMUL_CONTINUE)) 920 return rc; 921 ctxt->fetch.end += size; 922 return X86EMUL_CONTINUE; 923 } 924 925 static __always_inline int do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, 926 unsigned size) 927 { 928 unsigned done_size = ctxt->fetch.end - ctxt->fetch.ptr; 929 930 if (unlikely(done_size < size)) 931 return __do_insn_fetch_bytes(ctxt, size - done_size); 932 else 933 return X86EMUL_CONTINUE; 934 } 935 936 /* Fetch next part of the instruction being emulated. */ 937 #define insn_fetch(_type, _ctxt) \ 938 ({ _type _x; \ 939 \ 940 rc = do_insn_fetch_bytes(_ctxt, sizeof(_type)); \ 941 if (rc != X86EMUL_CONTINUE) \ 942 goto done; \ 943 ctxt->_eip += sizeof(_type); \ 944 memcpy(&_x, ctxt->fetch.ptr, sizeof(_type)); \ 945 ctxt->fetch.ptr += sizeof(_type); \ 946 _x; \ 947 }) 948 949 #define insn_fetch_arr(_arr, _size, _ctxt) \ 950 ({ \ 951 rc = do_insn_fetch_bytes(_ctxt, _size); \ 952 if (rc != X86EMUL_CONTINUE) \ 953 goto done; \ 954 ctxt->_eip += (_size); \ 955 memcpy(_arr, ctxt->fetch.ptr, _size); \ 956 ctxt->fetch.ptr += (_size); \ 957 }) 958 959 /* 960 * Given the 'reg' portion of a ModRM byte, and a register block, return a 961 * pointer into the block that addresses the relevant register. 962 * @highbyte_regs specifies whether to decode AH,CH,DH,BH. 963 */ 964 static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg, 965 int byteop) 966 { 967 void *p; 968 int highbyte_regs = (ctxt->rex_prefix == 0) && byteop; 969 970 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) 971 p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1; 972 else 973 p = reg_rmw(ctxt, modrm_reg); 974 return p; 975 } 976 977 static int read_descriptor(struct x86_emulate_ctxt *ctxt, 978 struct segmented_address addr, 979 u16 *size, unsigned long *address, int op_bytes) 980 { 981 int rc; 982 983 if (op_bytes == 2) 984 op_bytes = 3; 985 *address = 0; 986 rc = segmented_read_std(ctxt, addr, size, 2); 987 if (rc != X86EMUL_CONTINUE) 988 return rc; 989 addr.ea += 2; 990 rc = segmented_read_std(ctxt, addr, address, op_bytes); 991 return rc; 992 } 993 994 FASTOP2(add); 995 FASTOP2(or); 996 FASTOP2(adc); 997 FASTOP2(sbb); 998 FASTOP2(and); 999 FASTOP2(sub); 1000 FASTOP2(xor); 1001 FASTOP2(cmp); 1002 FASTOP2(test); 1003 1004 FASTOP1SRC2(mul, mul_ex); 1005 FASTOP1SRC2(imul, imul_ex); 1006 FASTOP1SRC2EX(div, div_ex); 1007 FASTOP1SRC2EX(idiv, idiv_ex); 1008 1009 FASTOP3WCL(shld); 1010 FASTOP3WCL(shrd); 1011 1012 FASTOP2W(imul); 1013 1014 FASTOP1(not); 1015 FASTOP1(neg); 1016 FASTOP1(inc); 1017 FASTOP1(dec); 1018 1019 FASTOP2CL(rol); 1020 FASTOP2CL(ror); 1021 FASTOP2CL(rcl); 1022 FASTOP2CL(rcr); 1023 FASTOP2CL(shl); 1024 FASTOP2CL(shr); 1025 FASTOP2CL(sar); 1026 1027 FASTOP2W(bsf); 1028 FASTOP2W(bsr); 1029 FASTOP2W(bt); 1030 FASTOP2W(bts); 1031 FASTOP2W(btr); 1032 FASTOP2W(btc); 1033 1034 FASTOP2(xadd); 1035 1036 FASTOP2R(cmp, cmp_r); 1037 1038 static int em_bsf_c(struct x86_emulate_ctxt *ctxt) 1039 { 1040 /* If src is zero, do not writeback, but update flags */ 1041 if (ctxt->src.val == 0) 1042 ctxt->dst.type = OP_NONE; 1043 return fastop(ctxt, em_bsf); 1044 } 1045 1046 static int em_bsr_c(struct x86_emulate_ctxt *ctxt) 1047 { 1048 /* If src is zero, do not writeback, but update flags */ 1049 if (ctxt->src.val == 0) 1050 ctxt->dst.type = OP_NONE; 1051 return fastop(ctxt, em_bsr); 1052 } 1053 1054 static __always_inline u8 test_cc(unsigned int condition, unsigned long flags) 1055 { 1056 u8 rc; 1057 void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf); 1058 1059 flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF; 1060 asm("push %[flags]; popf; " CALL_NOSPEC 1061 : "=a"(rc) : [thunk_target]"r"(fop), [flags]"r"(flags)); 1062 return rc; 1063 } 1064 1065 static void fetch_register_operand(struct operand *op) 1066 { 1067 switch (op->bytes) { 1068 case 1: 1069 op->val = *(u8 *)op->addr.reg; 1070 break; 1071 case 2: 1072 op->val = *(u16 *)op->addr.reg; 1073 break; 1074 case 4: 1075 op->val = *(u32 *)op->addr.reg; 1076 break; 1077 case 8: 1078 op->val = *(u64 *)op->addr.reg; 1079 break; 1080 } 1081 } 1082 1083 static int em_fninit(struct x86_emulate_ctxt *ctxt) 1084 { 1085 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 1086 return emulate_nm(ctxt); 1087 1088 kvm_fpu_get(); 1089 asm volatile("fninit"); 1090 kvm_fpu_put(); 1091 return X86EMUL_CONTINUE; 1092 } 1093 1094 static int em_fnstcw(struct x86_emulate_ctxt *ctxt) 1095 { 1096 u16 fcw; 1097 1098 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 1099 return emulate_nm(ctxt); 1100 1101 kvm_fpu_get(); 1102 asm volatile("fnstcw %0": "+m"(fcw)); 1103 kvm_fpu_put(); 1104 1105 ctxt->dst.val = fcw; 1106 1107 return X86EMUL_CONTINUE; 1108 } 1109 1110 static int em_fnstsw(struct x86_emulate_ctxt *ctxt) 1111 { 1112 u16 fsw; 1113 1114 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 1115 return emulate_nm(ctxt); 1116 1117 kvm_fpu_get(); 1118 asm volatile("fnstsw %0": "+m"(fsw)); 1119 kvm_fpu_put(); 1120 1121 ctxt->dst.val = fsw; 1122 1123 return X86EMUL_CONTINUE; 1124 } 1125 1126 static void decode_register_operand(struct x86_emulate_ctxt *ctxt, 1127 struct operand *op) 1128 { 1129 unsigned reg = ctxt->modrm_reg; 1130 1131 if (!(ctxt->d & ModRM)) 1132 reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3); 1133 1134 if (ctxt->d & Sse) { 1135 op->type = OP_XMM; 1136 op->bytes = 16; 1137 op->addr.xmm = reg; 1138 kvm_read_sse_reg(reg, &op->vec_val); 1139 return; 1140 } 1141 if (ctxt->d & Mmx) { 1142 reg &= 7; 1143 op->type = OP_MM; 1144 op->bytes = 8; 1145 op->addr.mm = reg; 1146 return; 1147 } 1148 1149 op->type = OP_REG; 1150 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 1151 op->addr.reg = decode_register(ctxt, reg, ctxt->d & ByteOp); 1152 1153 fetch_register_operand(op); 1154 op->orig_val = op->val; 1155 } 1156 1157 static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg) 1158 { 1159 if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP) 1160 ctxt->modrm_seg = VCPU_SREG_SS; 1161 } 1162 1163 static int decode_modrm(struct x86_emulate_ctxt *ctxt, 1164 struct operand *op) 1165 { 1166 u8 sib; 1167 int index_reg, base_reg, scale; 1168 int rc = X86EMUL_CONTINUE; 1169 ulong modrm_ea = 0; 1170 1171 ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8); /* REX.R */ 1172 index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */ 1173 base_reg = (ctxt->rex_prefix << 3) & 8; /* REX.B */ 1174 1175 ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6; 1176 ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3; 1177 ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07); 1178 ctxt->modrm_seg = VCPU_SREG_DS; 1179 1180 if (ctxt->modrm_mod == 3 || (ctxt->d & NoMod)) { 1181 op->type = OP_REG; 1182 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 1183 op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, 1184 ctxt->d & ByteOp); 1185 if (ctxt->d & Sse) { 1186 op->type = OP_XMM; 1187 op->bytes = 16; 1188 op->addr.xmm = ctxt->modrm_rm; 1189 kvm_read_sse_reg(ctxt->modrm_rm, &op->vec_val); 1190 return rc; 1191 } 1192 if (ctxt->d & Mmx) { 1193 op->type = OP_MM; 1194 op->bytes = 8; 1195 op->addr.mm = ctxt->modrm_rm & 7; 1196 return rc; 1197 } 1198 fetch_register_operand(op); 1199 return rc; 1200 } 1201 1202 op->type = OP_MEM; 1203 1204 if (ctxt->ad_bytes == 2) { 1205 unsigned bx = reg_read(ctxt, VCPU_REGS_RBX); 1206 unsigned bp = reg_read(ctxt, VCPU_REGS_RBP); 1207 unsigned si = reg_read(ctxt, VCPU_REGS_RSI); 1208 unsigned di = reg_read(ctxt, VCPU_REGS_RDI); 1209 1210 /* 16-bit ModR/M decode. */ 1211 switch (ctxt->modrm_mod) { 1212 case 0: 1213 if (ctxt->modrm_rm == 6) 1214 modrm_ea += insn_fetch(u16, ctxt); 1215 break; 1216 case 1: 1217 modrm_ea += insn_fetch(s8, ctxt); 1218 break; 1219 case 2: 1220 modrm_ea += insn_fetch(u16, ctxt); 1221 break; 1222 } 1223 switch (ctxt->modrm_rm) { 1224 case 0: 1225 modrm_ea += bx + si; 1226 break; 1227 case 1: 1228 modrm_ea += bx + di; 1229 break; 1230 case 2: 1231 modrm_ea += bp + si; 1232 break; 1233 case 3: 1234 modrm_ea += bp + di; 1235 break; 1236 case 4: 1237 modrm_ea += si; 1238 break; 1239 case 5: 1240 modrm_ea += di; 1241 break; 1242 case 6: 1243 if (ctxt->modrm_mod != 0) 1244 modrm_ea += bp; 1245 break; 1246 case 7: 1247 modrm_ea += bx; 1248 break; 1249 } 1250 if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 || 1251 (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0)) 1252 ctxt->modrm_seg = VCPU_SREG_SS; 1253 modrm_ea = (u16)modrm_ea; 1254 } else { 1255 /* 32/64-bit ModR/M decode. */ 1256 if ((ctxt->modrm_rm & 7) == 4) { 1257 sib = insn_fetch(u8, ctxt); 1258 index_reg |= (sib >> 3) & 7; 1259 base_reg |= sib & 7; 1260 scale = sib >> 6; 1261 1262 if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0) 1263 modrm_ea += insn_fetch(s32, ctxt); 1264 else { 1265 modrm_ea += reg_read(ctxt, base_reg); 1266 adjust_modrm_seg(ctxt, base_reg); 1267 /* Increment ESP on POP [ESP] */ 1268 if ((ctxt->d & IncSP) && 1269 base_reg == VCPU_REGS_RSP) 1270 modrm_ea += ctxt->op_bytes; 1271 } 1272 if (index_reg != 4) 1273 modrm_ea += reg_read(ctxt, index_reg) << scale; 1274 } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) { 1275 modrm_ea += insn_fetch(s32, ctxt); 1276 if (ctxt->mode == X86EMUL_MODE_PROT64) 1277 ctxt->rip_relative = 1; 1278 } else { 1279 base_reg = ctxt->modrm_rm; 1280 modrm_ea += reg_read(ctxt, base_reg); 1281 adjust_modrm_seg(ctxt, base_reg); 1282 } 1283 switch (ctxt->modrm_mod) { 1284 case 1: 1285 modrm_ea += insn_fetch(s8, ctxt); 1286 break; 1287 case 2: 1288 modrm_ea += insn_fetch(s32, ctxt); 1289 break; 1290 } 1291 } 1292 op->addr.mem.ea = modrm_ea; 1293 if (ctxt->ad_bytes != 8) 1294 ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea; 1295 1296 done: 1297 return rc; 1298 } 1299 1300 static int decode_abs(struct x86_emulate_ctxt *ctxt, 1301 struct operand *op) 1302 { 1303 int rc = X86EMUL_CONTINUE; 1304 1305 op->type = OP_MEM; 1306 switch (ctxt->ad_bytes) { 1307 case 2: 1308 op->addr.mem.ea = insn_fetch(u16, ctxt); 1309 break; 1310 case 4: 1311 op->addr.mem.ea = insn_fetch(u32, ctxt); 1312 break; 1313 case 8: 1314 op->addr.mem.ea = insn_fetch(u64, ctxt); 1315 break; 1316 } 1317 done: 1318 return rc; 1319 } 1320 1321 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt) 1322 { 1323 long sv = 0, mask; 1324 1325 if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) { 1326 mask = ~((long)ctxt->dst.bytes * 8 - 1); 1327 1328 if (ctxt->src.bytes == 2) 1329 sv = (s16)ctxt->src.val & (s16)mask; 1330 else if (ctxt->src.bytes == 4) 1331 sv = (s32)ctxt->src.val & (s32)mask; 1332 else 1333 sv = (s64)ctxt->src.val & (s64)mask; 1334 1335 ctxt->dst.addr.mem.ea = address_mask(ctxt, 1336 ctxt->dst.addr.mem.ea + (sv >> 3)); 1337 } 1338 1339 /* only subword offset */ 1340 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1; 1341 } 1342 1343 static int read_emulated(struct x86_emulate_ctxt *ctxt, 1344 unsigned long addr, void *dest, unsigned size) 1345 { 1346 int rc; 1347 struct read_cache *mc = &ctxt->mem_read; 1348 1349 if (mc->pos < mc->end) 1350 goto read_cached; 1351 1352 WARN_ON((mc->end + size) >= sizeof(mc->data)); 1353 1354 rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size, 1355 &ctxt->exception); 1356 if (rc != X86EMUL_CONTINUE) 1357 return rc; 1358 1359 mc->end += size; 1360 1361 read_cached: 1362 memcpy(dest, mc->data + mc->pos, size); 1363 mc->pos += size; 1364 return X86EMUL_CONTINUE; 1365 } 1366 1367 static int segmented_read(struct x86_emulate_ctxt *ctxt, 1368 struct segmented_address addr, 1369 void *data, 1370 unsigned size) 1371 { 1372 int rc; 1373 ulong linear; 1374 1375 rc = linearize(ctxt, addr, size, false, &linear); 1376 if (rc != X86EMUL_CONTINUE) 1377 return rc; 1378 return read_emulated(ctxt, linear, data, size); 1379 } 1380 1381 static int segmented_write(struct x86_emulate_ctxt *ctxt, 1382 struct segmented_address addr, 1383 const void *data, 1384 unsigned size) 1385 { 1386 int rc; 1387 ulong linear; 1388 1389 rc = linearize(ctxt, addr, size, true, &linear); 1390 if (rc != X86EMUL_CONTINUE) 1391 return rc; 1392 return ctxt->ops->write_emulated(ctxt, linear, data, size, 1393 &ctxt->exception); 1394 } 1395 1396 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt, 1397 struct segmented_address addr, 1398 const void *orig_data, const void *data, 1399 unsigned size) 1400 { 1401 int rc; 1402 ulong linear; 1403 1404 rc = linearize(ctxt, addr, size, true, &linear); 1405 if (rc != X86EMUL_CONTINUE) 1406 return rc; 1407 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data, 1408 size, &ctxt->exception); 1409 } 1410 1411 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, 1412 unsigned int size, unsigned short port, 1413 void *dest) 1414 { 1415 struct read_cache *rc = &ctxt->io_read; 1416 1417 if (rc->pos == rc->end) { /* refill pio read ahead */ 1418 unsigned int in_page, n; 1419 unsigned int count = ctxt->rep_prefix ? 1420 address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1; 1421 in_page = (ctxt->eflags & X86_EFLAGS_DF) ? 1422 offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) : 1423 PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)); 1424 n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count); 1425 if (n == 0) 1426 n = 1; 1427 rc->pos = rc->end = 0; 1428 if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n)) 1429 return 0; 1430 rc->end = n * size; 1431 } 1432 1433 if (ctxt->rep_prefix && (ctxt->d & String) && 1434 !(ctxt->eflags & X86_EFLAGS_DF)) { 1435 ctxt->dst.data = rc->data + rc->pos; 1436 ctxt->dst.type = OP_MEM_STR; 1437 ctxt->dst.count = (rc->end - rc->pos) / size; 1438 rc->pos = rc->end; 1439 } else { 1440 memcpy(dest, rc->data + rc->pos, size); 1441 rc->pos += size; 1442 } 1443 return 1; 1444 } 1445 1446 static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt, 1447 u16 index, struct desc_struct *desc) 1448 { 1449 struct desc_ptr dt; 1450 ulong addr; 1451 1452 ctxt->ops->get_idt(ctxt, &dt); 1453 1454 if (dt.size < index * 8 + 7) 1455 return emulate_gp(ctxt, index << 3 | 0x2); 1456 1457 addr = dt.address + index * 8; 1458 return linear_read_system(ctxt, addr, desc, sizeof(*desc)); 1459 } 1460 1461 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, 1462 u16 selector, struct desc_ptr *dt) 1463 { 1464 const struct x86_emulate_ops *ops = ctxt->ops; 1465 u32 base3 = 0; 1466 1467 if (selector & 1 << 2) { 1468 struct desc_struct desc; 1469 u16 sel; 1470 1471 memset(dt, 0, sizeof(*dt)); 1472 if (!ops->get_segment(ctxt, &sel, &desc, &base3, 1473 VCPU_SREG_LDTR)) 1474 return; 1475 1476 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ 1477 dt->address = get_desc_base(&desc) | ((u64)base3 << 32); 1478 } else 1479 ops->get_gdt(ctxt, dt); 1480 } 1481 1482 static int get_descriptor_ptr(struct x86_emulate_ctxt *ctxt, 1483 u16 selector, ulong *desc_addr_p) 1484 { 1485 struct desc_ptr dt; 1486 u16 index = selector >> 3; 1487 ulong addr; 1488 1489 get_descriptor_table_ptr(ctxt, selector, &dt); 1490 1491 if (dt.size < index * 8 + 7) 1492 return emulate_gp(ctxt, selector & 0xfffc); 1493 1494 addr = dt.address + index * 8; 1495 1496 #ifdef CONFIG_X86_64 1497 if (addr >> 32 != 0) { 1498 u64 efer = 0; 1499 1500 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 1501 if (!(efer & EFER_LMA)) 1502 addr &= (u32)-1; 1503 } 1504 #endif 1505 1506 *desc_addr_p = addr; 1507 return X86EMUL_CONTINUE; 1508 } 1509 1510 /* allowed just for 8 bytes segments */ 1511 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1512 u16 selector, struct desc_struct *desc, 1513 ulong *desc_addr_p) 1514 { 1515 int rc; 1516 1517 rc = get_descriptor_ptr(ctxt, selector, desc_addr_p); 1518 if (rc != X86EMUL_CONTINUE) 1519 return rc; 1520 1521 return linear_read_system(ctxt, *desc_addr_p, desc, sizeof(*desc)); 1522 } 1523 1524 /* allowed just for 8 bytes segments */ 1525 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1526 u16 selector, struct desc_struct *desc) 1527 { 1528 int rc; 1529 ulong addr; 1530 1531 rc = get_descriptor_ptr(ctxt, selector, &addr); 1532 if (rc != X86EMUL_CONTINUE) 1533 return rc; 1534 1535 return linear_write_system(ctxt, addr, desc, sizeof(*desc)); 1536 } 1537 1538 static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1539 u16 selector, int seg, u8 cpl, 1540 enum x86_transfer_type transfer, 1541 struct desc_struct *desc) 1542 { 1543 struct desc_struct seg_desc, old_desc; 1544 u8 dpl, rpl; 1545 unsigned err_vec = GP_VECTOR; 1546 u32 err_code = 0; 1547 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ 1548 ulong desc_addr; 1549 int ret; 1550 u16 dummy; 1551 u32 base3 = 0; 1552 1553 memset(&seg_desc, 0, sizeof(seg_desc)); 1554 1555 if (ctxt->mode == X86EMUL_MODE_REAL) { 1556 /* set real mode segment descriptor (keep limit etc. for 1557 * unreal mode) */ 1558 ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg); 1559 set_desc_base(&seg_desc, selector << 4); 1560 goto load; 1561 } else if (seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) { 1562 /* VM86 needs a clean new segment descriptor */ 1563 set_desc_base(&seg_desc, selector << 4); 1564 set_desc_limit(&seg_desc, 0xffff); 1565 seg_desc.type = 3; 1566 seg_desc.p = 1; 1567 seg_desc.s = 1; 1568 seg_desc.dpl = 3; 1569 goto load; 1570 } 1571 1572 rpl = selector & 3; 1573 1574 /* TR should be in GDT only */ 1575 if (seg == VCPU_SREG_TR && (selector & (1 << 2))) 1576 goto exception; 1577 1578 /* NULL selector is not valid for TR, CS and (except for long mode) SS */ 1579 if (null_selector) { 1580 if (seg == VCPU_SREG_CS || seg == VCPU_SREG_TR) 1581 goto exception; 1582 1583 if (seg == VCPU_SREG_SS) { 1584 if (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl) 1585 goto exception; 1586 1587 /* 1588 * ctxt->ops->set_segment expects the CPL to be in 1589 * SS.DPL, so fake an expand-up 32-bit data segment. 1590 */ 1591 seg_desc.type = 3; 1592 seg_desc.p = 1; 1593 seg_desc.s = 1; 1594 seg_desc.dpl = cpl; 1595 seg_desc.d = 1; 1596 seg_desc.g = 1; 1597 } 1598 1599 /* Skip all following checks */ 1600 goto load; 1601 } 1602 1603 ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr); 1604 if (ret != X86EMUL_CONTINUE) 1605 return ret; 1606 1607 err_code = selector & 0xfffc; 1608 err_vec = (transfer == X86_TRANSFER_TASK_SWITCH) ? TS_VECTOR : 1609 GP_VECTOR; 1610 1611 /* can't load system descriptor into segment selector */ 1612 if (seg <= VCPU_SREG_GS && !seg_desc.s) { 1613 if (transfer == X86_TRANSFER_CALL_JMP) 1614 return X86EMUL_UNHANDLEABLE; 1615 goto exception; 1616 } 1617 1618 if (!seg_desc.p) { 1619 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; 1620 goto exception; 1621 } 1622 1623 dpl = seg_desc.dpl; 1624 1625 switch (seg) { 1626 case VCPU_SREG_SS: 1627 /* 1628 * segment is not a writable data segment or segment 1629 * selector's RPL != CPL or segment selector's RPL != CPL 1630 */ 1631 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) 1632 goto exception; 1633 break; 1634 case VCPU_SREG_CS: 1635 if (!(seg_desc.type & 8)) 1636 goto exception; 1637 1638 if (seg_desc.type & 4) { 1639 /* conforming */ 1640 if (dpl > cpl) 1641 goto exception; 1642 } else { 1643 /* nonconforming */ 1644 if (rpl > cpl || dpl != cpl) 1645 goto exception; 1646 } 1647 /* in long-mode d/b must be clear if l is set */ 1648 if (seg_desc.d && seg_desc.l) { 1649 u64 efer = 0; 1650 1651 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 1652 if (efer & EFER_LMA) 1653 goto exception; 1654 } 1655 1656 /* CS(RPL) <- CPL */ 1657 selector = (selector & 0xfffc) | cpl; 1658 break; 1659 case VCPU_SREG_TR: 1660 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) 1661 goto exception; 1662 old_desc = seg_desc; 1663 seg_desc.type |= 2; /* busy */ 1664 ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc, 1665 sizeof(seg_desc), &ctxt->exception); 1666 if (ret != X86EMUL_CONTINUE) 1667 return ret; 1668 break; 1669 case VCPU_SREG_LDTR: 1670 if (seg_desc.s || seg_desc.type != 2) 1671 goto exception; 1672 break; 1673 default: /* DS, ES, FS, or GS */ 1674 /* 1675 * segment is not a data or readable code segment or 1676 * ((segment is a data or nonconforming code segment) 1677 * and (both RPL and CPL > DPL)) 1678 */ 1679 if ((seg_desc.type & 0xa) == 0x8 || 1680 (((seg_desc.type & 0xc) != 0xc) && 1681 (rpl > dpl && cpl > dpl))) 1682 goto exception; 1683 break; 1684 } 1685 1686 if (seg_desc.s) { 1687 /* mark segment as accessed */ 1688 if (!(seg_desc.type & 1)) { 1689 seg_desc.type |= 1; 1690 ret = write_segment_descriptor(ctxt, selector, 1691 &seg_desc); 1692 if (ret != X86EMUL_CONTINUE) 1693 return ret; 1694 } 1695 } else if (ctxt->mode == X86EMUL_MODE_PROT64) { 1696 ret = linear_read_system(ctxt, desc_addr+8, &base3, sizeof(base3)); 1697 if (ret != X86EMUL_CONTINUE) 1698 return ret; 1699 if (emul_is_noncanonical_address(get_desc_base(&seg_desc) | 1700 ((u64)base3 << 32), ctxt)) 1701 return emulate_gp(ctxt, 0); 1702 } 1703 load: 1704 ctxt->ops->set_segment(ctxt, selector, &seg_desc, base3, seg); 1705 if (desc) 1706 *desc = seg_desc; 1707 return X86EMUL_CONTINUE; 1708 exception: 1709 return emulate_exception(ctxt, err_vec, err_code, true); 1710 } 1711 1712 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1713 u16 selector, int seg) 1714 { 1715 u8 cpl = ctxt->ops->cpl(ctxt); 1716 1717 /* 1718 * None of MOV, POP and LSS can load a NULL selector in CPL=3, but 1719 * they can load it at CPL<3 (Intel's manual says only LSS can, 1720 * but it's wrong). 1721 * 1722 * However, the Intel manual says that putting IST=1/DPL=3 in 1723 * an interrupt gate will result in SS=3 (the AMD manual instead 1724 * says it doesn't), so allow SS=3 in __load_segment_descriptor 1725 * and only forbid it here. 1726 */ 1727 if (seg == VCPU_SREG_SS && selector == 3 && 1728 ctxt->mode == X86EMUL_MODE_PROT64) 1729 return emulate_exception(ctxt, GP_VECTOR, 0, true); 1730 1731 return __load_segment_descriptor(ctxt, selector, seg, cpl, 1732 X86_TRANSFER_NONE, NULL); 1733 } 1734 1735 static void write_register_operand(struct operand *op) 1736 { 1737 return assign_register(op->addr.reg, op->val, op->bytes); 1738 } 1739 1740 static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op) 1741 { 1742 switch (op->type) { 1743 case OP_REG: 1744 write_register_operand(op); 1745 break; 1746 case OP_MEM: 1747 if (ctxt->lock_prefix) 1748 return segmented_cmpxchg(ctxt, 1749 op->addr.mem, 1750 &op->orig_val, 1751 &op->val, 1752 op->bytes); 1753 else 1754 return segmented_write(ctxt, 1755 op->addr.mem, 1756 &op->val, 1757 op->bytes); 1758 break; 1759 case OP_MEM_STR: 1760 return segmented_write(ctxt, 1761 op->addr.mem, 1762 op->data, 1763 op->bytes * op->count); 1764 break; 1765 case OP_XMM: 1766 kvm_write_sse_reg(op->addr.xmm, &op->vec_val); 1767 break; 1768 case OP_MM: 1769 kvm_write_mmx_reg(op->addr.mm, &op->mm_val); 1770 break; 1771 case OP_NONE: 1772 /* no writeback */ 1773 break; 1774 default: 1775 break; 1776 } 1777 return X86EMUL_CONTINUE; 1778 } 1779 1780 static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes) 1781 { 1782 struct segmented_address addr; 1783 1784 rsp_increment(ctxt, -bytes); 1785 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); 1786 addr.seg = VCPU_SREG_SS; 1787 1788 return segmented_write(ctxt, addr, data, bytes); 1789 } 1790 1791 static int em_push(struct x86_emulate_ctxt *ctxt) 1792 { 1793 /* Disable writeback. */ 1794 ctxt->dst.type = OP_NONE; 1795 return push(ctxt, &ctxt->src.val, ctxt->op_bytes); 1796 } 1797 1798 static int emulate_pop(struct x86_emulate_ctxt *ctxt, 1799 void *dest, int len) 1800 { 1801 int rc; 1802 struct segmented_address addr; 1803 1804 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt); 1805 addr.seg = VCPU_SREG_SS; 1806 rc = segmented_read(ctxt, addr, dest, len); 1807 if (rc != X86EMUL_CONTINUE) 1808 return rc; 1809 1810 rsp_increment(ctxt, len); 1811 return rc; 1812 } 1813 1814 static int em_pop(struct x86_emulate_ctxt *ctxt) 1815 { 1816 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes); 1817 } 1818 1819 static int emulate_popf(struct x86_emulate_ctxt *ctxt, 1820 void *dest, int len) 1821 { 1822 int rc; 1823 unsigned long val, change_mask; 1824 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT; 1825 int cpl = ctxt->ops->cpl(ctxt); 1826 1827 rc = emulate_pop(ctxt, &val, len); 1828 if (rc != X86EMUL_CONTINUE) 1829 return rc; 1830 1831 change_mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | 1832 X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_OF | 1833 X86_EFLAGS_TF | X86_EFLAGS_DF | X86_EFLAGS_NT | 1834 X86_EFLAGS_AC | X86_EFLAGS_ID; 1835 1836 switch(ctxt->mode) { 1837 case X86EMUL_MODE_PROT64: 1838 case X86EMUL_MODE_PROT32: 1839 case X86EMUL_MODE_PROT16: 1840 if (cpl == 0) 1841 change_mask |= X86_EFLAGS_IOPL; 1842 if (cpl <= iopl) 1843 change_mask |= X86_EFLAGS_IF; 1844 break; 1845 case X86EMUL_MODE_VM86: 1846 if (iopl < 3) 1847 return emulate_gp(ctxt, 0); 1848 change_mask |= X86_EFLAGS_IF; 1849 break; 1850 default: /* real mode */ 1851 change_mask |= (X86_EFLAGS_IOPL | X86_EFLAGS_IF); 1852 break; 1853 } 1854 1855 *(unsigned long *)dest = 1856 (ctxt->eflags & ~change_mask) | (val & change_mask); 1857 1858 return rc; 1859 } 1860 1861 static int em_popf(struct x86_emulate_ctxt *ctxt) 1862 { 1863 ctxt->dst.type = OP_REG; 1864 ctxt->dst.addr.reg = &ctxt->eflags; 1865 ctxt->dst.bytes = ctxt->op_bytes; 1866 return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes); 1867 } 1868 1869 static int em_enter(struct x86_emulate_ctxt *ctxt) 1870 { 1871 int rc; 1872 unsigned frame_size = ctxt->src.val; 1873 unsigned nesting_level = ctxt->src2.val & 31; 1874 ulong rbp; 1875 1876 if (nesting_level) 1877 return X86EMUL_UNHANDLEABLE; 1878 1879 rbp = reg_read(ctxt, VCPU_REGS_RBP); 1880 rc = push(ctxt, &rbp, stack_size(ctxt)); 1881 if (rc != X86EMUL_CONTINUE) 1882 return rc; 1883 assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP), 1884 stack_mask(ctxt)); 1885 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), 1886 reg_read(ctxt, VCPU_REGS_RSP) - frame_size, 1887 stack_mask(ctxt)); 1888 return X86EMUL_CONTINUE; 1889 } 1890 1891 static int em_leave(struct x86_emulate_ctxt *ctxt) 1892 { 1893 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP), 1894 stack_mask(ctxt)); 1895 return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes); 1896 } 1897 1898 static int em_push_sreg(struct x86_emulate_ctxt *ctxt) 1899 { 1900 int seg = ctxt->src2.val; 1901 1902 ctxt->src.val = get_segment_selector(ctxt, seg); 1903 if (ctxt->op_bytes == 4) { 1904 rsp_increment(ctxt, -2); 1905 ctxt->op_bytes = 2; 1906 } 1907 1908 return em_push(ctxt); 1909 } 1910 1911 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt) 1912 { 1913 int seg = ctxt->src2.val; 1914 unsigned long selector; 1915 int rc; 1916 1917 rc = emulate_pop(ctxt, &selector, 2); 1918 if (rc != X86EMUL_CONTINUE) 1919 return rc; 1920 1921 if (ctxt->modrm_reg == VCPU_SREG_SS) 1922 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; 1923 if (ctxt->op_bytes > 2) 1924 rsp_increment(ctxt, ctxt->op_bytes - 2); 1925 1926 rc = load_segment_descriptor(ctxt, (u16)selector, seg); 1927 return rc; 1928 } 1929 1930 static int em_pusha(struct x86_emulate_ctxt *ctxt) 1931 { 1932 unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP); 1933 int rc = X86EMUL_CONTINUE; 1934 int reg = VCPU_REGS_RAX; 1935 1936 while (reg <= VCPU_REGS_RDI) { 1937 (reg == VCPU_REGS_RSP) ? 1938 (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg)); 1939 1940 rc = em_push(ctxt); 1941 if (rc != X86EMUL_CONTINUE) 1942 return rc; 1943 1944 ++reg; 1945 } 1946 1947 return rc; 1948 } 1949 1950 static int em_pushf(struct x86_emulate_ctxt *ctxt) 1951 { 1952 ctxt->src.val = (unsigned long)ctxt->eflags & ~X86_EFLAGS_VM; 1953 return em_push(ctxt); 1954 } 1955 1956 static int em_popa(struct x86_emulate_ctxt *ctxt) 1957 { 1958 int rc = X86EMUL_CONTINUE; 1959 int reg = VCPU_REGS_RDI; 1960 u32 val; 1961 1962 while (reg >= VCPU_REGS_RAX) { 1963 if (reg == VCPU_REGS_RSP) { 1964 rsp_increment(ctxt, ctxt->op_bytes); 1965 --reg; 1966 } 1967 1968 rc = emulate_pop(ctxt, &val, ctxt->op_bytes); 1969 if (rc != X86EMUL_CONTINUE) 1970 break; 1971 assign_register(reg_rmw(ctxt, reg), val, ctxt->op_bytes); 1972 --reg; 1973 } 1974 return rc; 1975 } 1976 1977 static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) 1978 { 1979 const struct x86_emulate_ops *ops = ctxt->ops; 1980 int rc; 1981 struct desc_ptr dt; 1982 gva_t cs_addr; 1983 gva_t eip_addr; 1984 u16 cs, eip; 1985 1986 /* TODO: Add limit checks */ 1987 ctxt->src.val = ctxt->eflags; 1988 rc = em_push(ctxt); 1989 if (rc != X86EMUL_CONTINUE) 1990 return rc; 1991 1992 ctxt->eflags &= ~(X86_EFLAGS_IF | X86_EFLAGS_TF | X86_EFLAGS_AC); 1993 1994 ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS); 1995 rc = em_push(ctxt); 1996 if (rc != X86EMUL_CONTINUE) 1997 return rc; 1998 1999 ctxt->src.val = ctxt->_eip; 2000 rc = em_push(ctxt); 2001 if (rc != X86EMUL_CONTINUE) 2002 return rc; 2003 2004 ops->get_idt(ctxt, &dt); 2005 2006 eip_addr = dt.address + (irq << 2); 2007 cs_addr = dt.address + (irq << 2) + 2; 2008 2009 rc = linear_read_system(ctxt, cs_addr, &cs, 2); 2010 if (rc != X86EMUL_CONTINUE) 2011 return rc; 2012 2013 rc = linear_read_system(ctxt, eip_addr, &eip, 2); 2014 if (rc != X86EMUL_CONTINUE) 2015 return rc; 2016 2017 rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS); 2018 if (rc != X86EMUL_CONTINUE) 2019 return rc; 2020 2021 ctxt->_eip = eip; 2022 2023 return rc; 2024 } 2025 2026 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq) 2027 { 2028 int rc; 2029 2030 invalidate_registers(ctxt); 2031 rc = __emulate_int_real(ctxt, irq); 2032 if (rc == X86EMUL_CONTINUE) 2033 writeback_registers(ctxt); 2034 return rc; 2035 } 2036 2037 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq) 2038 { 2039 switch(ctxt->mode) { 2040 case X86EMUL_MODE_REAL: 2041 return __emulate_int_real(ctxt, irq); 2042 case X86EMUL_MODE_VM86: 2043 case X86EMUL_MODE_PROT16: 2044 case X86EMUL_MODE_PROT32: 2045 case X86EMUL_MODE_PROT64: 2046 default: 2047 /* Protected mode interrupts unimplemented yet */ 2048 return X86EMUL_UNHANDLEABLE; 2049 } 2050 } 2051 2052 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt) 2053 { 2054 int rc = X86EMUL_CONTINUE; 2055 unsigned long temp_eip = 0; 2056 unsigned long temp_eflags = 0; 2057 unsigned long cs = 0; 2058 unsigned long mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | 2059 X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_TF | 2060 X86_EFLAGS_IF | X86_EFLAGS_DF | X86_EFLAGS_OF | 2061 X86_EFLAGS_IOPL | X86_EFLAGS_NT | X86_EFLAGS_RF | 2062 X86_EFLAGS_AC | X86_EFLAGS_ID | 2063 X86_EFLAGS_FIXED; 2064 unsigned long vm86_mask = X86_EFLAGS_VM | X86_EFLAGS_VIF | 2065 X86_EFLAGS_VIP; 2066 2067 /* TODO: Add stack limit check */ 2068 2069 rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes); 2070 2071 if (rc != X86EMUL_CONTINUE) 2072 return rc; 2073 2074 if (temp_eip & ~0xffff) 2075 return emulate_gp(ctxt, 0); 2076 2077 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); 2078 2079 if (rc != X86EMUL_CONTINUE) 2080 return rc; 2081 2082 rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes); 2083 2084 if (rc != X86EMUL_CONTINUE) 2085 return rc; 2086 2087 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS); 2088 2089 if (rc != X86EMUL_CONTINUE) 2090 return rc; 2091 2092 ctxt->_eip = temp_eip; 2093 2094 if (ctxt->op_bytes == 4) 2095 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask)); 2096 else if (ctxt->op_bytes == 2) { 2097 ctxt->eflags &= ~0xffff; 2098 ctxt->eflags |= temp_eflags; 2099 } 2100 2101 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */ 2102 ctxt->eflags |= X86_EFLAGS_FIXED; 2103 ctxt->ops->set_nmi_mask(ctxt, false); 2104 2105 return rc; 2106 } 2107 2108 static int em_iret(struct x86_emulate_ctxt *ctxt) 2109 { 2110 switch(ctxt->mode) { 2111 case X86EMUL_MODE_REAL: 2112 return emulate_iret_real(ctxt); 2113 case X86EMUL_MODE_VM86: 2114 case X86EMUL_MODE_PROT16: 2115 case X86EMUL_MODE_PROT32: 2116 case X86EMUL_MODE_PROT64: 2117 default: 2118 /* iret from protected mode unimplemented yet */ 2119 return X86EMUL_UNHANDLEABLE; 2120 } 2121 } 2122 2123 static int em_jmp_far(struct x86_emulate_ctxt *ctxt) 2124 { 2125 int rc; 2126 unsigned short sel; 2127 struct desc_struct new_desc; 2128 u8 cpl = ctxt->ops->cpl(ctxt); 2129 2130 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); 2131 2132 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, 2133 X86_TRANSFER_CALL_JMP, 2134 &new_desc); 2135 if (rc != X86EMUL_CONTINUE) 2136 return rc; 2137 2138 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc); 2139 /* Error handling is not implemented. */ 2140 if (rc != X86EMUL_CONTINUE) 2141 return X86EMUL_UNHANDLEABLE; 2142 2143 return rc; 2144 } 2145 2146 static int em_jmp_abs(struct x86_emulate_ctxt *ctxt) 2147 { 2148 return assign_eip_near(ctxt, ctxt->src.val); 2149 } 2150 2151 static int em_call_near_abs(struct x86_emulate_ctxt *ctxt) 2152 { 2153 int rc; 2154 long int old_eip; 2155 2156 old_eip = ctxt->_eip; 2157 rc = assign_eip_near(ctxt, ctxt->src.val); 2158 if (rc != X86EMUL_CONTINUE) 2159 return rc; 2160 ctxt->src.val = old_eip; 2161 rc = em_push(ctxt); 2162 return rc; 2163 } 2164 2165 static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt) 2166 { 2167 u64 old = ctxt->dst.orig_val64; 2168 2169 if (ctxt->dst.bytes == 16) 2170 return X86EMUL_UNHANDLEABLE; 2171 2172 if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) || 2173 ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) { 2174 *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0); 2175 *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32); 2176 ctxt->eflags &= ~X86_EFLAGS_ZF; 2177 } else { 2178 ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) | 2179 (u32) reg_read(ctxt, VCPU_REGS_RBX); 2180 2181 ctxt->eflags |= X86_EFLAGS_ZF; 2182 } 2183 return X86EMUL_CONTINUE; 2184 } 2185 2186 static int em_ret(struct x86_emulate_ctxt *ctxt) 2187 { 2188 int rc; 2189 unsigned long eip; 2190 2191 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); 2192 if (rc != X86EMUL_CONTINUE) 2193 return rc; 2194 2195 return assign_eip_near(ctxt, eip); 2196 } 2197 2198 static int em_ret_far(struct x86_emulate_ctxt *ctxt) 2199 { 2200 int rc; 2201 unsigned long eip, cs; 2202 int cpl = ctxt->ops->cpl(ctxt); 2203 struct desc_struct new_desc; 2204 2205 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); 2206 if (rc != X86EMUL_CONTINUE) 2207 return rc; 2208 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes); 2209 if (rc != X86EMUL_CONTINUE) 2210 return rc; 2211 /* Outer-privilege level return is not implemented */ 2212 if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl) 2213 return X86EMUL_UNHANDLEABLE; 2214 rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, cpl, 2215 X86_TRANSFER_RET, 2216 &new_desc); 2217 if (rc != X86EMUL_CONTINUE) 2218 return rc; 2219 rc = assign_eip_far(ctxt, eip, &new_desc); 2220 /* Error handling is not implemented. */ 2221 if (rc != X86EMUL_CONTINUE) 2222 return X86EMUL_UNHANDLEABLE; 2223 2224 return rc; 2225 } 2226 2227 static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt) 2228 { 2229 int rc; 2230 2231 rc = em_ret_far(ctxt); 2232 if (rc != X86EMUL_CONTINUE) 2233 return rc; 2234 rsp_increment(ctxt, ctxt->src.val); 2235 return X86EMUL_CONTINUE; 2236 } 2237 2238 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt) 2239 { 2240 /* Save real source value, then compare EAX against destination. */ 2241 ctxt->dst.orig_val = ctxt->dst.val; 2242 ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX); 2243 ctxt->src.orig_val = ctxt->src.val; 2244 ctxt->src.val = ctxt->dst.orig_val; 2245 fastop(ctxt, em_cmp); 2246 2247 if (ctxt->eflags & X86_EFLAGS_ZF) { 2248 /* Success: write back to memory; no update of EAX */ 2249 ctxt->src.type = OP_NONE; 2250 ctxt->dst.val = ctxt->src.orig_val; 2251 } else { 2252 /* Failure: write the value we saw to EAX. */ 2253 ctxt->src.type = OP_REG; 2254 ctxt->src.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); 2255 ctxt->src.val = ctxt->dst.orig_val; 2256 /* Create write-cycle to dest by writing the same value */ 2257 ctxt->dst.val = ctxt->dst.orig_val; 2258 } 2259 return X86EMUL_CONTINUE; 2260 } 2261 2262 static int em_lseg(struct x86_emulate_ctxt *ctxt) 2263 { 2264 int seg = ctxt->src2.val; 2265 unsigned short sel; 2266 int rc; 2267 2268 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); 2269 2270 rc = load_segment_descriptor(ctxt, sel, seg); 2271 if (rc != X86EMUL_CONTINUE) 2272 return rc; 2273 2274 ctxt->dst.val = ctxt->src.val; 2275 return rc; 2276 } 2277 2278 static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt) 2279 { 2280 #ifdef CONFIG_X86_64 2281 return ctxt->ops->guest_has_long_mode(ctxt); 2282 #else 2283 return false; 2284 #endif 2285 } 2286 2287 static void rsm_set_desc_flags(struct desc_struct *desc, u32 flags) 2288 { 2289 desc->g = (flags >> 23) & 1; 2290 desc->d = (flags >> 22) & 1; 2291 desc->l = (flags >> 21) & 1; 2292 desc->avl = (flags >> 20) & 1; 2293 desc->p = (flags >> 15) & 1; 2294 desc->dpl = (flags >> 13) & 3; 2295 desc->s = (flags >> 12) & 1; 2296 desc->type = (flags >> 8) & 15; 2297 } 2298 2299 static int rsm_load_seg_32(struct x86_emulate_ctxt *ctxt, const char *smstate, 2300 int n) 2301 { 2302 struct desc_struct desc; 2303 int offset; 2304 u16 selector; 2305 2306 selector = GET_SMSTATE(u32, smstate, 0x7fa8 + n * 4); 2307 2308 if (n < 3) 2309 offset = 0x7f84 + n * 12; 2310 else 2311 offset = 0x7f2c + (n - 3) * 12; 2312 2313 set_desc_base(&desc, GET_SMSTATE(u32, smstate, offset + 8)); 2314 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, offset + 4)); 2315 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, offset)); 2316 ctxt->ops->set_segment(ctxt, selector, &desc, 0, n); 2317 return X86EMUL_CONTINUE; 2318 } 2319 2320 #ifdef CONFIG_X86_64 2321 static int rsm_load_seg_64(struct x86_emulate_ctxt *ctxt, const char *smstate, 2322 int n) 2323 { 2324 struct desc_struct desc; 2325 int offset; 2326 u16 selector; 2327 u32 base3; 2328 2329 offset = 0x7e00 + n * 16; 2330 2331 selector = GET_SMSTATE(u16, smstate, offset); 2332 rsm_set_desc_flags(&desc, GET_SMSTATE(u16, smstate, offset + 2) << 8); 2333 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, offset + 4)); 2334 set_desc_base(&desc, GET_SMSTATE(u32, smstate, offset + 8)); 2335 base3 = GET_SMSTATE(u32, smstate, offset + 12); 2336 2337 ctxt->ops->set_segment(ctxt, selector, &desc, base3, n); 2338 return X86EMUL_CONTINUE; 2339 } 2340 #endif 2341 2342 static int rsm_enter_protected_mode(struct x86_emulate_ctxt *ctxt, 2343 u64 cr0, u64 cr3, u64 cr4) 2344 { 2345 int bad; 2346 u64 pcid; 2347 2348 /* In order to later set CR4.PCIDE, CR3[11:0] must be zero. */ 2349 pcid = 0; 2350 if (cr4 & X86_CR4_PCIDE) { 2351 pcid = cr3 & 0xfff; 2352 cr3 &= ~0xfff; 2353 } 2354 2355 bad = ctxt->ops->set_cr(ctxt, 3, cr3); 2356 if (bad) 2357 return X86EMUL_UNHANDLEABLE; 2358 2359 /* 2360 * First enable PAE, long mode needs it before CR0.PG = 1 is set. 2361 * Then enable protected mode. However, PCID cannot be enabled 2362 * if EFER.LMA=0, so set it separately. 2363 */ 2364 bad = ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE); 2365 if (bad) 2366 return X86EMUL_UNHANDLEABLE; 2367 2368 bad = ctxt->ops->set_cr(ctxt, 0, cr0); 2369 if (bad) 2370 return X86EMUL_UNHANDLEABLE; 2371 2372 if (cr4 & X86_CR4_PCIDE) { 2373 bad = ctxt->ops->set_cr(ctxt, 4, cr4); 2374 if (bad) 2375 return X86EMUL_UNHANDLEABLE; 2376 if (pcid) { 2377 bad = ctxt->ops->set_cr(ctxt, 3, cr3 | pcid); 2378 if (bad) 2379 return X86EMUL_UNHANDLEABLE; 2380 } 2381 2382 } 2383 2384 return X86EMUL_CONTINUE; 2385 } 2386 2387 static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, 2388 const char *smstate) 2389 { 2390 struct desc_struct desc; 2391 struct desc_ptr dt; 2392 u16 selector; 2393 u32 val, cr0, cr3, cr4; 2394 int i; 2395 2396 cr0 = GET_SMSTATE(u32, smstate, 0x7ffc); 2397 cr3 = GET_SMSTATE(u32, smstate, 0x7ff8); 2398 ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7ff4) | X86_EFLAGS_FIXED; 2399 ctxt->_eip = GET_SMSTATE(u32, smstate, 0x7ff0); 2400 2401 for (i = 0; i < 8; i++) 2402 *reg_write(ctxt, i) = GET_SMSTATE(u32, smstate, 0x7fd0 + i * 4); 2403 2404 val = GET_SMSTATE(u32, smstate, 0x7fcc); 2405 2406 if (ctxt->ops->set_dr(ctxt, 6, val)) 2407 return X86EMUL_UNHANDLEABLE; 2408 2409 val = GET_SMSTATE(u32, smstate, 0x7fc8); 2410 2411 if (ctxt->ops->set_dr(ctxt, 7, val)) 2412 return X86EMUL_UNHANDLEABLE; 2413 2414 selector = GET_SMSTATE(u32, smstate, 0x7fc4); 2415 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7f64)); 2416 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7f60)); 2417 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7f5c)); 2418 ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_TR); 2419 2420 selector = GET_SMSTATE(u32, smstate, 0x7fc0); 2421 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7f80)); 2422 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7f7c)); 2423 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7f78)); 2424 ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_LDTR); 2425 2426 dt.address = GET_SMSTATE(u32, smstate, 0x7f74); 2427 dt.size = GET_SMSTATE(u32, smstate, 0x7f70); 2428 ctxt->ops->set_gdt(ctxt, &dt); 2429 2430 dt.address = GET_SMSTATE(u32, smstate, 0x7f58); 2431 dt.size = GET_SMSTATE(u32, smstate, 0x7f54); 2432 ctxt->ops->set_idt(ctxt, &dt); 2433 2434 for (i = 0; i < 6; i++) { 2435 int r = rsm_load_seg_32(ctxt, smstate, i); 2436 if (r != X86EMUL_CONTINUE) 2437 return r; 2438 } 2439 2440 cr4 = GET_SMSTATE(u32, smstate, 0x7f14); 2441 2442 ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smstate, 0x7ef8)); 2443 2444 return rsm_enter_protected_mode(ctxt, cr0, cr3, cr4); 2445 } 2446 2447 #ifdef CONFIG_X86_64 2448 static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, 2449 const char *smstate) 2450 { 2451 struct desc_struct desc; 2452 struct desc_ptr dt; 2453 u64 val, cr0, cr3, cr4; 2454 u32 base3; 2455 u16 selector; 2456 int i, r; 2457 2458 for (i = 0; i < 16; i++) 2459 *reg_write(ctxt, i) = GET_SMSTATE(u64, smstate, 0x7ff8 - i * 8); 2460 2461 ctxt->_eip = GET_SMSTATE(u64, smstate, 0x7f78); 2462 ctxt->eflags = GET_SMSTATE(u32, smstate, 0x7f70) | X86_EFLAGS_FIXED; 2463 2464 val = GET_SMSTATE(u64, smstate, 0x7f68); 2465 2466 if (ctxt->ops->set_dr(ctxt, 6, val)) 2467 return X86EMUL_UNHANDLEABLE; 2468 2469 val = GET_SMSTATE(u64, smstate, 0x7f60); 2470 2471 if (ctxt->ops->set_dr(ctxt, 7, val)) 2472 return X86EMUL_UNHANDLEABLE; 2473 2474 cr0 = GET_SMSTATE(u64, smstate, 0x7f58); 2475 cr3 = GET_SMSTATE(u64, smstate, 0x7f50); 2476 cr4 = GET_SMSTATE(u64, smstate, 0x7f48); 2477 ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smstate, 0x7f00)); 2478 val = GET_SMSTATE(u64, smstate, 0x7ed0); 2479 2480 if (ctxt->ops->set_msr(ctxt, MSR_EFER, val & ~EFER_LMA)) 2481 return X86EMUL_UNHANDLEABLE; 2482 2483 selector = GET_SMSTATE(u32, smstate, 0x7e90); 2484 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7e92) << 8); 2485 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7e94)); 2486 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7e98)); 2487 base3 = GET_SMSTATE(u32, smstate, 0x7e9c); 2488 ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_TR); 2489 2490 dt.size = GET_SMSTATE(u32, smstate, 0x7e84); 2491 dt.address = GET_SMSTATE(u64, smstate, 0x7e88); 2492 ctxt->ops->set_idt(ctxt, &dt); 2493 2494 selector = GET_SMSTATE(u32, smstate, 0x7e70); 2495 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smstate, 0x7e72) << 8); 2496 set_desc_limit(&desc, GET_SMSTATE(u32, smstate, 0x7e74)); 2497 set_desc_base(&desc, GET_SMSTATE(u32, smstate, 0x7e78)); 2498 base3 = GET_SMSTATE(u32, smstate, 0x7e7c); 2499 ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_LDTR); 2500 2501 dt.size = GET_SMSTATE(u32, smstate, 0x7e64); 2502 dt.address = GET_SMSTATE(u64, smstate, 0x7e68); 2503 ctxt->ops->set_gdt(ctxt, &dt); 2504 2505 r = rsm_enter_protected_mode(ctxt, cr0, cr3, cr4); 2506 if (r != X86EMUL_CONTINUE) 2507 return r; 2508 2509 for (i = 0; i < 6; i++) { 2510 r = rsm_load_seg_64(ctxt, smstate, i); 2511 if (r != X86EMUL_CONTINUE) 2512 return r; 2513 } 2514 2515 return X86EMUL_CONTINUE; 2516 } 2517 #endif 2518 2519 static int em_rsm(struct x86_emulate_ctxt *ctxt) 2520 { 2521 unsigned long cr0, cr4, efer; 2522 char buf[512]; 2523 u64 smbase; 2524 int ret; 2525 2526 if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_MASK) == 0) 2527 return emulate_ud(ctxt); 2528 2529 smbase = ctxt->ops->get_smbase(ctxt); 2530 2531 ret = ctxt->ops->read_phys(ctxt, smbase + 0xfe00, buf, sizeof(buf)); 2532 if (ret != X86EMUL_CONTINUE) 2533 return X86EMUL_UNHANDLEABLE; 2534 2535 if ((ctxt->ops->get_hflags(ctxt) & X86EMUL_SMM_INSIDE_NMI_MASK) == 0) 2536 ctxt->ops->set_nmi_mask(ctxt, false); 2537 2538 ctxt->ops->exiting_smm(ctxt); 2539 2540 /* 2541 * Get back to real mode, to prepare a safe state in which to load 2542 * CR0/CR3/CR4/EFER. It's all a bit more complicated if the vCPU 2543 * supports long mode. 2544 */ 2545 if (emulator_has_longmode(ctxt)) { 2546 struct desc_struct cs_desc; 2547 2548 /* Zero CR4.PCIDE before CR0.PG. */ 2549 cr4 = ctxt->ops->get_cr(ctxt, 4); 2550 if (cr4 & X86_CR4_PCIDE) 2551 ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE); 2552 2553 /* A 32-bit code segment is required to clear EFER.LMA. */ 2554 memset(&cs_desc, 0, sizeof(cs_desc)); 2555 cs_desc.type = 0xb; 2556 cs_desc.s = cs_desc.g = cs_desc.p = 1; 2557 ctxt->ops->set_segment(ctxt, 0, &cs_desc, 0, VCPU_SREG_CS); 2558 } 2559 2560 /* For the 64-bit case, this will clear EFER.LMA. */ 2561 cr0 = ctxt->ops->get_cr(ctxt, 0); 2562 if (cr0 & X86_CR0_PE) 2563 ctxt->ops->set_cr(ctxt, 0, cr0 & ~(X86_CR0_PG | X86_CR0_PE)); 2564 2565 if (emulator_has_longmode(ctxt)) { 2566 /* Clear CR4.PAE before clearing EFER.LME. */ 2567 cr4 = ctxt->ops->get_cr(ctxt, 4); 2568 if (cr4 & X86_CR4_PAE) 2569 ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PAE); 2570 2571 /* And finally go back to 32-bit mode. */ 2572 efer = 0; 2573 ctxt->ops->set_msr(ctxt, MSR_EFER, efer); 2574 } 2575 2576 /* 2577 * Give leave_smm() a chance to make ISA-specific changes to the vCPU 2578 * state (e.g. enter guest mode) before loading state from the SMM 2579 * state-save area. 2580 */ 2581 if (ctxt->ops->leave_smm(ctxt, buf)) 2582 goto emulate_shutdown; 2583 2584 #ifdef CONFIG_X86_64 2585 if (emulator_has_longmode(ctxt)) 2586 ret = rsm_load_state_64(ctxt, buf); 2587 else 2588 #endif 2589 ret = rsm_load_state_32(ctxt, buf); 2590 2591 if (ret != X86EMUL_CONTINUE) 2592 goto emulate_shutdown; 2593 2594 /* 2595 * Note, the ctxt->ops callbacks are responsible for handling side 2596 * effects when writing MSRs and CRs, e.g. MMU context resets, CPUID 2597 * runtime updates, etc... If that changes, e.g. this flow is moved 2598 * out of the emulator to make it look more like enter_smm(), then 2599 * those side effects need to be explicitly handled for both success 2600 * and shutdown. 2601 */ 2602 return X86EMUL_CONTINUE; 2603 2604 emulate_shutdown: 2605 ctxt->ops->triple_fault(ctxt); 2606 return X86EMUL_CONTINUE; 2607 } 2608 2609 static void 2610 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, 2611 struct desc_struct *cs, struct desc_struct *ss) 2612 { 2613 cs->l = 0; /* will be adjusted later */ 2614 set_desc_base(cs, 0); /* flat segment */ 2615 cs->g = 1; /* 4kb granularity */ 2616 set_desc_limit(cs, 0xfffff); /* 4GB limit */ 2617 cs->type = 0x0b; /* Read, Execute, Accessed */ 2618 cs->s = 1; 2619 cs->dpl = 0; /* will be adjusted later */ 2620 cs->p = 1; 2621 cs->d = 1; 2622 cs->avl = 0; 2623 2624 set_desc_base(ss, 0); /* flat segment */ 2625 set_desc_limit(ss, 0xfffff); /* 4GB limit */ 2626 ss->g = 1; /* 4kb granularity */ 2627 ss->s = 1; 2628 ss->type = 0x03; /* Read/Write, Accessed */ 2629 ss->d = 1; /* 32bit stack segment */ 2630 ss->dpl = 0; 2631 ss->p = 1; 2632 ss->l = 0; 2633 ss->avl = 0; 2634 } 2635 2636 static bool vendor_intel(struct x86_emulate_ctxt *ctxt) 2637 { 2638 u32 eax, ebx, ecx, edx; 2639 2640 eax = ecx = 0; 2641 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, true); 2642 return is_guest_vendor_intel(ebx, ecx, edx); 2643 } 2644 2645 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt) 2646 { 2647 const struct x86_emulate_ops *ops = ctxt->ops; 2648 u32 eax, ebx, ecx, edx; 2649 2650 /* 2651 * syscall should always be enabled in longmode - so only become 2652 * vendor specific (cpuid) if other modes are active... 2653 */ 2654 if (ctxt->mode == X86EMUL_MODE_PROT64) 2655 return true; 2656 2657 eax = 0x00000000; 2658 ecx = 0x00000000; 2659 ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, true); 2660 /* 2661 * remark: Intel CPUs only support "syscall" in 64bit longmode. Also a 2662 * 64bit guest with a 32bit compat-app running will #UD !! While this 2663 * behaviour can be fixed (by emulating) into AMD response - CPUs of 2664 * AMD can't behave like Intel. 2665 */ 2666 if (is_guest_vendor_intel(ebx, ecx, edx)) 2667 return false; 2668 2669 if (is_guest_vendor_amd(ebx, ecx, edx) || 2670 is_guest_vendor_hygon(ebx, ecx, edx)) 2671 return true; 2672 2673 /* 2674 * default: (not Intel, not AMD, not Hygon), apply Intel's 2675 * stricter rules... 2676 */ 2677 return false; 2678 } 2679 2680 static int em_syscall(struct x86_emulate_ctxt *ctxt) 2681 { 2682 const struct x86_emulate_ops *ops = ctxt->ops; 2683 struct desc_struct cs, ss; 2684 u64 msr_data; 2685 u16 cs_sel, ss_sel; 2686 u64 efer = 0; 2687 2688 /* syscall is not available in real mode */ 2689 if (ctxt->mode == X86EMUL_MODE_REAL || 2690 ctxt->mode == X86EMUL_MODE_VM86) 2691 return emulate_ud(ctxt); 2692 2693 if (!(em_syscall_is_enabled(ctxt))) 2694 return emulate_ud(ctxt); 2695 2696 ops->get_msr(ctxt, MSR_EFER, &efer); 2697 if (!(efer & EFER_SCE)) 2698 return emulate_ud(ctxt); 2699 2700 setup_syscalls_segments(ctxt, &cs, &ss); 2701 ops->get_msr(ctxt, MSR_STAR, &msr_data); 2702 msr_data >>= 32; 2703 cs_sel = (u16)(msr_data & 0xfffc); 2704 ss_sel = (u16)(msr_data + 8); 2705 2706 if (efer & EFER_LMA) { 2707 cs.d = 0; 2708 cs.l = 1; 2709 } 2710 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2711 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2712 2713 *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip; 2714 if (efer & EFER_LMA) { 2715 #ifdef CONFIG_X86_64 2716 *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags; 2717 2718 ops->get_msr(ctxt, 2719 ctxt->mode == X86EMUL_MODE_PROT64 ? 2720 MSR_LSTAR : MSR_CSTAR, &msr_data); 2721 ctxt->_eip = msr_data; 2722 2723 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data); 2724 ctxt->eflags &= ~msr_data; 2725 ctxt->eflags |= X86_EFLAGS_FIXED; 2726 #endif 2727 } else { 2728 /* legacy mode */ 2729 ops->get_msr(ctxt, MSR_STAR, &msr_data); 2730 ctxt->_eip = (u32)msr_data; 2731 2732 ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); 2733 } 2734 2735 ctxt->tf = (ctxt->eflags & X86_EFLAGS_TF) != 0; 2736 return X86EMUL_CONTINUE; 2737 } 2738 2739 static int em_sysenter(struct x86_emulate_ctxt *ctxt) 2740 { 2741 const struct x86_emulate_ops *ops = ctxt->ops; 2742 struct desc_struct cs, ss; 2743 u64 msr_data; 2744 u16 cs_sel, ss_sel; 2745 u64 efer = 0; 2746 2747 ops->get_msr(ctxt, MSR_EFER, &efer); 2748 /* inject #GP if in real mode */ 2749 if (ctxt->mode == X86EMUL_MODE_REAL) 2750 return emulate_gp(ctxt, 0); 2751 2752 /* 2753 * Not recognized on AMD in compat mode (but is recognized in legacy 2754 * mode). 2755 */ 2756 if ((ctxt->mode != X86EMUL_MODE_PROT64) && (efer & EFER_LMA) 2757 && !vendor_intel(ctxt)) 2758 return emulate_ud(ctxt); 2759 2760 /* sysenter/sysexit have not been tested in 64bit mode. */ 2761 if (ctxt->mode == X86EMUL_MODE_PROT64) 2762 return X86EMUL_UNHANDLEABLE; 2763 2764 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); 2765 if ((msr_data & 0xfffc) == 0x0) 2766 return emulate_gp(ctxt, 0); 2767 2768 setup_syscalls_segments(ctxt, &cs, &ss); 2769 ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF); 2770 cs_sel = (u16)msr_data & ~SEGMENT_RPL_MASK; 2771 ss_sel = cs_sel + 8; 2772 if (efer & EFER_LMA) { 2773 cs.d = 0; 2774 cs.l = 1; 2775 } 2776 2777 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2778 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2779 2780 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data); 2781 ctxt->_eip = (efer & EFER_LMA) ? msr_data : (u32)msr_data; 2782 2783 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data); 2784 *reg_write(ctxt, VCPU_REGS_RSP) = (efer & EFER_LMA) ? msr_data : 2785 (u32)msr_data; 2786 if (efer & EFER_LMA) 2787 ctxt->mode = X86EMUL_MODE_PROT64; 2788 2789 return X86EMUL_CONTINUE; 2790 } 2791 2792 static int em_sysexit(struct x86_emulate_ctxt *ctxt) 2793 { 2794 const struct x86_emulate_ops *ops = ctxt->ops; 2795 struct desc_struct cs, ss; 2796 u64 msr_data, rcx, rdx; 2797 int usermode; 2798 u16 cs_sel = 0, ss_sel = 0; 2799 2800 /* inject #GP if in real mode or Virtual 8086 mode */ 2801 if (ctxt->mode == X86EMUL_MODE_REAL || 2802 ctxt->mode == X86EMUL_MODE_VM86) 2803 return emulate_gp(ctxt, 0); 2804 2805 setup_syscalls_segments(ctxt, &cs, &ss); 2806 2807 if ((ctxt->rex_prefix & 0x8) != 0x0) 2808 usermode = X86EMUL_MODE_PROT64; 2809 else 2810 usermode = X86EMUL_MODE_PROT32; 2811 2812 rcx = reg_read(ctxt, VCPU_REGS_RCX); 2813 rdx = reg_read(ctxt, VCPU_REGS_RDX); 2814 2815 cs.dpl = 3; 2816 ss.dpl = 3; 2817 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); 2818 switch (usermode) { 2819 case X86EMUL_MODE_PROT32: 2820 cs_sel = (u16)(msr_data + 16); 2821 if ((msr_data & 0xfffc) == 0x0) 2822 return emulate_gp(ctxt, 0); 2823 ss_sel = (u16)(msr_data + 24); 2824 rcx = (u32)rcx; 2825 rdx = (u32)rdx; 2826 break; 2827 case X86EMUL_MODE_PROT64: 2828 cs_sel = (u16)(msr_data + 32); 2829 if (msr_data == 0x0) 2830 return emulate_gp(ctxt, 0); 2831 ss_sel = cs_sel + 8; 2832 cs.d = 0; 2833 cs.l = 1; 2834 if (emul_is_noncanonical_address(rcx, ctxt) || 2835 emul_is_noncanonical_address(rdx, ctxt)) 2836 return emulate_gp(ctxt, 0); 2837 break; 2838 } 2839 cs_sel |= SEGMENT_RPL_MASK; 2840 ss_sel |= SEGMENT_RPL_MASK; 2841 2842 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2843 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2844 2845 ctxt->_eip = rdx; 2846 *reg_write(ctxt, VCPU_REGS_RSP) = rcx; 2847 2848 return X86EMUL_CONTINUE; 2849 } 2850 2851 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt) 2852 { 2853 int iopl; 2854 if (ctxt->mode == X86EMUL_MODE_REAL) 2855 return false; 2856 if (ctxt->mode == X86EMUL_MODE_VM86) 2857 return true; 2858 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT; 2859 return ctxt->ops->cpl(ctxt) > iopl; 2860 } 2861 2862 #define VMWARE_PORT_VMPORT (0x5658) 2863 #define VMWARE_PORT_VMRPC (0x5659) 2864 2865 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, 2866 u16 port, u16 len) 2867 { 2868 const struct x86_emulate_ops *ops = ctxt->ops; 2869 struct desc_struct tr_seg; 2870 u32 base3; 2871 int r; 2872 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7; 2873 unsigned mask = (1 << len) - 1; 2874 unsigned long base; 2875 2876 /* 2877 * VMware allows access to these ports even if denied 2878 * by TSS I/O permission bitmap. Mimic behavior. 2879 */ 2880 if (enable_vmware_backdoor && 2881 ((port == VMWARE_PORT_VMPORT) || (port == VMWARE_PORT_VMRPC))) 2882 return true; 2883 2884 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR); 2885 if (!tr_seg.p) 2886 return false; 2887 if (desc_limit_scaled(&tr_seg) < 103) 2888 return false; 2889 base = get_desc_base(&tr_seg); 2890 #ifdef CONFIG_X86_64 2891 base |= ((u64)base3) << 32; 2892 #endif 2893 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL, true); 2894 if (r != X86EMUL_CONTINUE) 2895 return false; 2896 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg)) 2897 return false; 2898 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL, true); 2899 if (r != X86EMUL_CONTINUE) 2900 return false; 2901 if ((perm >> bit_idx) & mask) 2902 return false; 2903 return true; 2904 } 2905 2906 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, 2907 u16 port, u16 len) 2908 { 2909 if (ctxt->perm_ok) 2910 return true; 2911 2912 if (emulator_bad_iopl(ctxt)) 2913 if (!emulator_io_port_access_allowed(ctxt, port, len)) 2914 return false; 2915 2916 ctxt->perm_ok = true; 2917 2918 return true; 2919 } 2920 2921 static void string_registers_quirk(struct x86_emulate_ctxt *ctxt) 2922 { 2923 /* 2924 * Intel CPUs mask the counter and pointers in quite strange 2925 * manner when ECX is zero due to REP-string optimizations. 2926 */ 2927 #ifdef CONFIG_X86_64 2928 if (ctxt->ad_bytes != 4 || !vendor_intel(ctxt)) 2929 return; 2930 2931 *reg_write(ctxt, VCPU_REGS_RCX) = 0; 2932 2933 switch (ctxt->b) { 2934 case 0xa4: /* movsb */ 2935 case 0xa5: /* movsd/w */ 2936 *reg_rmw(ctxt, VCPU_REGS_RSI) &= (u32)-1; 2937 fallthrough; 2938 case 0xaa: /* stosb */ 2939 case 0xab: /* stosd/w */ 2940 *reg_rmw(ctxt, VCPU_REGS_RDI) &= (u32)-1; 2941 } 2942 #endif 2943 } 2944 2945 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, 2946 struct tss_segment_16 *tss) 2947 { 2948 tss->ip = ctxt->_eip; 2949 tss->flag = ctxt->eflags; 2950 tss->ax = reg_read(ctxt, VCPU_REGS_RAX); 2951 tss->cx = reg_read(ctxt, VCPU_REGS_RCX); 2952 tss->dx = reg_read(ctxt, VCPU_REGS_RDX); 2953 tss->bx = reg_read(ctxt, VCPU_REGS_RBX); 2954 tss->sp = reg_read(ctxt, VCPU_REGS_RSP); 2955 tss->bp = reg_read(ctxt, VCPU_REGS_RBP); 2956 tss->si = reg_read(ctxt, VCPU_REGS_RSI); 2957 tss->di = reg_read(ctxt, VCPU_REGS_RDI); 2958 2959 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); 2960 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); 2961 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); 2962 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); 2963 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR); 2964 } 2965 2966 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, 2967 struct tss_segment_16 *tss) 2968 { 2969 int ret; 2970 u8 cpl; 2971 2972 ctxt->_eip = tss->ip; 2973 ctxt->eflags = tss->flag | 2; 2974 *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax; 2975 *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx; 2976 *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx; 2977 *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx; 2978 *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp; 2979 *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp; 2980 *reg_write(ctxt, VCPU_REGS_RSI) = tss->si; 2981 *reg_write(ctxt, VCPU_REGS_RDI) = tss->di; 2982 2983 /* 2984 * SDM says that segment selectors are loaded before segment 2985 * descriptors 2986 */ 2987 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); 2988 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); 2989 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); 2990 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); 2991 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); 2992 2993 cpl = tss->cs & 3; 2994 2995 /* 2996 * Now load segment descriptors. If fault happens at this stage 2997 * it is handled in a context of new task 2998 */ 2999 ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl, 3000 X86_TRANSFER_TASK_SWITCH, NULL); 3001 if (ret != X86EMUL_CONTINUE) 3002 return ret; 3003 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, 3004 X86_TRANSFER_TASK_SWITCH, NULL); 3005 if (ret != X86EMUL_CONTINUE) 3006 return ret; 3007 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, 3008 X86_TRANSFER_TASK_SWITCH, NULL); 3009 if (ret != X86EMUL_CONTINUE) 3010 return ret; 3011 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, 3012 X86_TRANSFER_TASK_SWITCH, NULL); 3013 if (ret != X86EMUL_CONTINUE) 3014 return ret; 3015 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, 3016 X86_TRANSFER_TASK_SWITCH, NULL); 3017 if (ret != X86EMUL_CONTINUE) 3018 return ret; 3019 3020 return X86EMUL_CONTINUE; 3021 } 3022 3023 static int task_switch_16(struct x86_emulate_ctxt *ctxt, 3024 u16 tss_selector, u16 old_tss_sel, 3025 ulong old_tss_base, struct desc_struct *new_desc) 3026 { 3027 struct tss_segment_16 tss_seg; 3028 int ret; 3029 u32 new_tss_base = get_desc_base(new_desc); 3030 3031 ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof(tss_seg)); 3032 if (ret != X86EMUL_CONTINUE) 3033 return ret; 3034 3035 save_state_to_tss16(ctxt, &tss_seg); 3036 3037 ret = linear_write_system(ctxt, old_tss_base, &tss_seg, sizeof(tss_seg)); 3038 if (ret != X86EMUL_CONTINUE) 3039 return ret; 3040 3041 ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof(tss_seg)); 3042 if (ret != X86EMUL_CONTINUE) 3043 return ret; 3044 3045 if (old_tss_sel != 0xffff) { 3046 tss_seg.prev_task_link = old_tss_sel; 3047 3048 ret = linear_write_system(ctxt, new_tss_base, 3049 &tss_seg.prev_task_link, 3050 sizeof(tss_seg.prev_task_link)); 3051 if (ret != X86EMUL_CONTINUE) 3052 return ret; 3053 } 3054 3055 return load_state_from_tss16(ctxt, &tss_seg); 3056 } 3057 3058 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, 3059 struct tss_segment_32 *tss) 3060 { 3061 /* CR3 and ldt selector are not saved intentionally */ 3062 tss->eip = ctxt->_eip; 3063 tss->eflags = ctxt->eflags; 3064 tss->eax = reg_read(ctxt, VCPU_REGS_RAX); 3065 tss->ecx = reg_read(ctxt, VCPU_REGS_RCX); 3066 tss->edx = reg_read(ctxt, VCPU_REGS_RDX); 3067 tss->ebx = reg_read(ctxt, VCPU_REGS_RBX); 3068 tss->esp = reg_read(ctxt, VCPU_REGS_RSP); 3069 tss->ebp = reg_read(ctxt, VCPU_REGS_RBP); 3070 tss->esi = reg_read(ctxt, VCPU_REGS_RSI); 3071 tss->edi = reg_read(ctxt, VCPU_REGS_RDI); 3072 3073 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); 3074 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); 3075 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); 3076 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); 3077 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); 3078 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); 3079 } 3080 3081 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, 3082 struct tss_segment_32 *tss) 3083 { 3084 int ret; 3085 u8 cpl; 3086 3087 if (ctxt->ops->set_cr(ctxt, 3, tss->cr3)) 3088 return emulate_gp(ctxt, 0); 3089 ctxt->_eip = tss->eip; 3090 ctxt->eflags = tss->eflags | 2; 3091 3092 /* General purpose registers */ 3093 *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax; 3094 *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx; 3095 *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx; 3096 *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx; 3097 *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp; 3098 *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp; 3099 *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi; 3100 *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi; 3101 3102 /* 3103 * SDM says that segment selectors are loaded before segment 3104 * descriptors. This is important because CPL checks will 3105 * use CS.RPL. 3106 */ 3107 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); 3108 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); 3109 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); 3110 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); 3111 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); 3112 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); 3113 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); 3114 3115 /* 3116 * If we're switching between Protected Mode and VM86, we need to make 3117 * sure to update the mode before loading the segment descriptors so 3118 * that the selectors are interpreted correctly. 3119 */ 3120 if (ctxt->eflags & X86_EFLAGS_VM) { 3121 ctxt->mode = X86EMUL_MODE_VM86; 3122 cpl = 3; 3123 } else { 3124 ctxt->mode = X86EMUL_MODE_PROT32; 3125 cpl = tss->cs & 3; 3126 } 3127 3128 /* 3129 * Now load segment descriptors. If fault happens at this stage 3130 * it is handled in a context of new task 3131 */ 3132 ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR, 3133 cpl, X86_TRANSFER_TASK_SWITCH, NULL); 3134 if (ret != X86EMUL_CONTINUE) 3135 return ret; 3136 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl, 3137 X86_TRANSFER_TASK_SWITCH, NULL); 3138 if (ret != X86EMUL_CONTINUE) 3139 return ret; 3140 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl, 3141 X86_TRANSFER_TASK_SWITCH, NULL); 3142 if (ret != X86EMUL_CONTINUE) 3143 return ret; 3144 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl, 3145 X86_TRANSFER_TASK_SWITCH, NULL); 3146 if (ret != X86EMUL_CONTINUE) 3147 return ret; 3148 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl, 3149 X86_TRANSFER_TASK_SWITCH, NULL); 3150 if (ret != X86EMUL_CONTINUE) 3151 return ret; 3152 ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl, 3153 X86_TRANSFER_TASK_SWITCH, NULL); 3154 if (ret != X86EMUL_CONTINUE) 3155 return ret; 3156 ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl, 3157 X86_TRANSFER_TASK_SWITCH, NULL); 3158 3159 return ret; 3160 } 3161 3162 static int task_switch_32(struct x86_emulate_ctxt *ctxt, 3163 u16 tss_selector, u16 old_tss_sel, 3164 ulong old_tss_base, struct desc_struct *new_desc) 3165 { 3166 struct tss_segment_32 tss_seg; 3167 int ret; 3168 u32 new_tss_base = get_desc_base(new_desc); 3169 u32 eip_offset = offsetof(struct tss_segment_32, eip); 3170 u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector); 3171 3172 ret = linear_read_system(ctxt, old_tss_base, &tss_seg, sizeof(tss_seg)); 3173 if (ret != X86EMUL_CONTINUE) 3174 return ret; 3175 3176 save_state_to_tss32(ctxt, &tss_seg); 3177 3178 /* Only GP registers and segment selectors are saved */ 3179 ret = linear_write_system(ctxt, old_tss_base + eip_offset, &tss_seg.eip, 3180 ldt_sel_offset - eip_offset); 3181 if (ret != X86EMUL_CONTINUE) 3182 return ret; 3183 3184 ret = linear_read_system(ctxt, new_tss_base, &tss_seg, sizeof(tss_seg)); 3185 if (ret != X86EMUL_CONTINUE) 3186 return ret; 3187 3188 if (old_tss_sel != 0xffff) { 3189 tss_seg.prev_task_link = old_tss_sel; 3190 3191 ret = linear_write_system(ctxt, new_tss_base, 3192 &tss_seg.prev_task_link, 3193 sizeof(tss_seg.prev_task_link)); 3194 if (ret != X86EMUL_CONTINUE) 3195 return ret; 3196 } 3197 3198 return load_state_from_tss32(ctxt, &tss_seg); 3199 } 3200 3201 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, 3202 u16 tss_selector, int idt_index, int reason, 3203 bool has_error_code, u32 error_code) 3204 { 3205 const struct x86_emulate_ops *ops = ctxt->ops; 3206 struct desc_struct curr_tss_desc, next_tss_desc; 3207 int ret; 3208 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR); 3209 ulong old_tss_base = 3210 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); 3211 u32 desc_limit; 3212 ulong desc_addr, dr7; 3213 3214 /* FIXME: old_tss_base == ~0 ? */ 3215 3216 ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr); 3217 if (ret != X86EMUL_CONTINUE) 3218 return ret; 3219 ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr); 3220 if (ret != X86EMUL_CONTINUE) 3221 return ret; 3222 3223 /* FIXME: check that next_tss_desc is tss */ 3224 3225 /* 3226 * Check privileges. The three cases are task switch caused by... 3227 * 3228 * 1. jmp/call/int to task gate: Check against DPL of the task gate 3229 * 2. Exception/IRQ/iret: No check is performed 3230 * 3. jmp/call to TSS/task-gate: No check is performed since the 3231 * hardware checks it before exiting. 3232 */ 3233 if (reason == TASK_SWITCH_GATE) { 3234 if (idt_index != -1) { 3235 /* Software interrupts */ 3236 struct desc_struct task_gate_desc; 3237 int dpl; 3238 3239 ret = read_interrupt_descriptor(ctxt, idt_index, 3240 &task_gate_desc); 3241 if (ret != X86EMUL_CONTINUE) 3242 return ret; 3243 3244 dpl = task_gate_desc.dpl; 3245 if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl) 3246 return emulate_gp(ctxt, (idt_index << 3) | 0x2); 3247 } 3248 } 3249 3250 desc_limit = desc_limit_scaled(&next_tss_desc); 3251 if (!next_tss_desc.p || 3252 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || 3253 desc_limit < 0x2b)) { 3254 return emulate_ts(ctxt, tss_selector & 0xfffc); 3255 } 3256 3257 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { 3258 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ 3259 write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc); 3260 } 3261 3262 if (reason == TASK_SWITCH_IRET) 3263 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; 3264 3265 /* set back link to prev task only if NT bit is set in eflags 3266 note that old_tss_sel is not used after this point */ 3267 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) 3268 old_tss_sel = 0xffff; 3269 3270 if (next_tss_desc.type & 8) 3271 ret = task_switch_32(ctxt, tss_selector, old_tss_sel, 3272 old_tss_base, &next_tss_desc); 3273 else 3274 ret = task_switch_16(ctxt, tss_selector, old_tss_sel, 3275 old_tss_base, &next_tss_desc); 3276 if (ret != X86EMUL_CONTINUE) 3277 return ret; 3278 3279 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) 3280 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; 3281 3282 if (reason != TASK_SWITCH_IRET) { 3283 next_tss_desc.type |= (1 << 1); /* set busy flag */ 3284 write_segment_descriptor(ctxt, tss_selector, &next_tss_desc); 3285 } 3286 3287 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS); 3288 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR); 3289 3290 if (has_error_code) { 3291 ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; 3292 ctxt->lock_prefix = 0; 3293 ctxt->src.val = (unsigned long) error_code; 3294 ret = em_push(ctxt); 3295 } 3296 3297 ops->get_dr(ctxt, 7, &dr7); 3298 ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN)); 3299 3300 return ret; 3301 } 3302 3303 int emulator_task_switch(struct x86_emulate_ctxt *ctxt, 3304 u16 tss_selector, int idt_index, int reason, 3305 bool has_error_code, u32 error_code) 3306 { 3307 int rc; 3308 3309 invalidate_registers(ctxt); 3310 ctxt->_eip = ctxt->eip; 3311 ctxt->dst.type = OP_NONE; 3312 3313 rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason, 3314 has_error_code, error_code); 3315 3316 if (rc == X86EMUL_CONTINUE) { 3317 ctxt->eip = ctxt->_eip; 3318 writeback_registers(ctxt); 3319 } 3320 3321 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 3322 } 3323 3324 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg, 3325 struct operand *op) 3326 { 3327 int df = (ctxt->eflags & X86_EFLAGS_DF) ? -op->count : op->count; 3328 3329 register_address_increment(ctxt, reg, df * op->bytes); 3330 op->addr.mem.ea = register_address(ctxt, reg); 3331 } 3332 3333 static int em_das(struct x86_emulate_ctxt *ctxt) 3334 { 3335 u8 al, old_al; 3336 bool af, cf, old_cf; 3337 3338 cf = ctxt->eflags & X86_EFLAGS_CF; 3339 al = ctxt->dst.val; 3340 3341 old_al = al; 3342 old_cf = cf; 3343 cf = false; 3344 af = ctxt->eflags & X86_EFLAGS_AF; 3345 if ((al & 0x0f) > 9 || af) { 3346 al -= 6; 3347 cf = old_cf | (al >= 250); 3348 af = true; 3349 } else { 3350 af = false; 3351 } 3352 if (old_al > 0x99 || old_cf) { 3353 al -= 0x60; 3354 cf = true; 3355 } 3356 3357 ctxt->dst.val = al; 3358 /* Set PF, ZF, SF */ 3359 ctxt->src.type = OP_IMM; 3360 ctxt->src.val = 0; 3361 ctxt->src.bytes = 1; 3362 fastop(ctxt, em_or); 3363 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF); 3364 if (cf) 3365 ctxt->eflags |= X86_EFLAGS_CF; 3366 if (af) 3367 ctxt->eflags |= X86_EFLAGS_AF; 3368 return X86EMUL_CONTINUE; 3369 } 3370 3371 static int em_aam(struct x86_emulate_ctxt *ctxt) 3372 { 3373 u8 al, ah; 3374 3375 if (ctxt->src.val == 0) 3376 return emulate_de(ctxt); 3377 3378 al = ctxt->dst.val & 0xff; 3379 ah = al / ctxt->src.val; 3380 al %= ctxt->src.val; 3381 3382 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8); 3383 3384 /* Set PF, ZF, SF */ 3385 ctxt->src.type = OP_IMM; 3386 ctxt->src.val = 0; 3387 ctxt->src.bytes = 1; 3388 fastop(ctxt, em_or); 3389 3390 return X86EMUL_CONTINUE; 3391 } 3392 3393 static int em_aad(struct x86_emulate_ctxt *ctxt) 3394 { 3395 u8 al = ctxt->dst.val & 0xff; 3396 u8 ah = (ctxt->dst.val >> 8) & 0xff; 3397 3398 al = (al + (ah * ctxt->src.val)) & 0xff; 3399 3400 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al; 3401 3402 /* Set PF, ZF, SF */ 3403 ctxt->src.type = OP_IMM; 3404 ctxt->src.val = 0; 3405 ctxt->src.bytes = 1; 3406 fastop(ctxt, em_or); 3407 3408 return X86EMUL_CONTINUE; 3409 } 3410 3411 static int em_call(struct x86_emulate_ctxt *ctxt) 3412 { 3413 int rc; 3414 long rel = ctxt->src.val; 3415 3416 ctxt->src.val = (unsigned long)ctxt->_eip; 3417 rc = jmp_rel(ctxt, rel); 3418 if (rc != X86EMUL_CONTINUE) 3419 return rc; 3420 return em_push(ctxt); 3421 } 3422 3423 static int em_call_far(struct x86_emulate_ctxt *ctxt) 3424 { 3425 u16 sel, old_cs; 3426 ulong old_eip; 3427 int rc; 3428 struct desc_struct old_desc, new_desc; 3429 const struct x86_emulate_ops *ops = ctxt->ops; 3430 int cpl = ctxt->ops->cpl(ctxt); 3431 enum x86emul_mode prev_mode = ctxt->mode; 3432 3433 old_eip = ctxt->_eip; 3434 ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS); 3435 3436 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2); 3437 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, 3438 X86_TRANSFER_CALL_JMP, &new_desc); 3439 if (rc != X86EMUL_CONTINUE) 3440 return rc; 3441 3442 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc); 3443 if (rc != X86EMUL_CONTINUE) 3444 goto fail; 3445 3446 ctxt->src.val = old_cs; 3447 rc = em_push(ctxt); 3448 if (rc != X86EMUL_CONTINUE) 3449 goto fail; 3450 3451 ctxt->src.val = old_eip; 3452 rc = em_push(ctxt); 3453 /* If we failed, we tainted the memory, but the very least we should 3454 restore cs */ 3455 if (rc != X86EMUL_CONTINUE) { 3456 pr_warn_once("faulting far call emulation tainted memory\n"); 3457 goto fail; 3458 } 3459 return rc; 3460 fail: 3461 ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS); 3462 ctxt->mode = prev_mode; 3463 return rc; 3464 3465 } 3466 3467 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt) 3468 { 3469 int rc; 3470 unsigned long eip; 3471 3472 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes); 3473 if (rc != X86EMUL_CONTINUE) 3474 return rc; 3475 rc = assign_eip_near(ctxt, eip); 3476 if (rc != X86EMUL_CONTINUE) 3477 return rc; 3478 rsp_increment(ctxt, ctxt->src.val); 3479 return X86EMUL_CONTINUE; 3480 } 3481 3482 static int em_xchg(struct x86_emulate_ctxt *ctxt) 3483 { 3484 /* Write back the register source. */ 3485 ctxt->src.val = ctxt->dst.val; 3486 write_register_operand(&ctxt->src); 3487 3488 /* Write back the memory destination with implicit LOCK prefix. */ 3489 ctxt->dst.val = ctxt->src.orig_val; 3490 ctxt->lock_prefix = 1; 3491 return X86EMUL_CONTINUE; 3492 } 3493 3494 static int em_imul_3op(struct x86_emulate_ctxt *ctxt) 3495 { 3496 ctxt->dst.val = ctxt->src2.val; 3497 return fastop(ctxt, em_imul); 3498 } 3499 3500 static int em_cwd(struct x86_emulate_ctxt *ctxt) 3501 { 3502 ctxt->dst.type = OP_REG; 3503 ctxt->dst.bytes = ctxt->src.bytes; 3504 ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); 3505 ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1); 3506 3507 return X86EMUL_CONTINUE; 3508 } 3509 3510 static int em_rdpid(struct x86_emulate_ctxt *ctxt) 3511 { 3512 u64 tsc_aux = 0; 3513 3514 if (ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux)) 3515 return emulate_ud(ctxt); 3516 ctxt->dst.val = tsc_aux; 3517 return X86EMUL_CONTINUE; 3518 } 3519 3520 static int em_rdtsc(struct x86_emulate_ctxt *ctxt) 3521 { 3522 u64 tsc = 0; 3523 3524 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc); 3525 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc; 3526 *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32; 3527 return X86EMUL_CONTINUE; 3528 } 3529 3530 static int em_rdpmc(struct x86_emulate_ctxt *ctxt) 3531 { 3532 u64 pmc; 3533 3534 if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc)) 3535 return emulate_gp(ctxt, 0); 3536 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc; 3537 *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32; 3538 return X86EMUL_CONTINUE; 3539 } 3540 3541 static int em_mov(struct x86_emulate_ctxt *ctxt) 3542 { 3543 memcpy(ctxt->dst.valptr, ctxt->src.valptr, sizeof(ctxt->src.valptr)); 3544 return X86EMUL_CONTINUE; 3545 } 3546 3547 static int em_movbe(struct x86_emulate_ctxt *ctxt) 3548 { 3549 u16 tmp; 3550 3551 if (!ctxt->ops->guest_has_movbe(ctxt)) 3552 return emulate_ud(ctxt); 3553 3554 switch (ctxt->op_bytes) { 3555 case 2: 3556 /* 3557 * From MOVBE definition: "...When the operand size is 16 bits, 3558 * the upper word of the destination register remains unchanged 3559 * ..." 3560 * 3561 * Both casting ->valptr and ->val to u16 breaks strict aliasing 3562 * rules so we have to do the operation almost per hand. 3563 */ 3564 tmp = (u16)ctxt->src.val; 3565 ctxt->dst.val &= ~0xffffUL; 3566 ctxt->dst.val |= (unsigned long)swab16(tmp); 3567 break; 3568 case 4: 3569 ctxt->dst.val = swab32((u32)ctxt->src.val); 3570 break; 3571 case 8: 3572 ctxt->dst.val = swab64(ctxt->src.val); 3573 break; 3574 default: 3575 BUG(); 3576 } 3577 return X86EMUL_CONTINUE; 3578 } 3579 3580 static int em_cr_write(struct x86_emulate_ctxt *ctxt) 3581 { 3582 if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val)) 3583 return emulate_gp(ctxt, 0); 3584 3585 /* Disable writeback. */ 3586 ctxt->dst.type = OP_NONE; 3587 return X86EMUL_CONTINUE; 3588 } 3589 3590 static int em_dr_write(struct x86_emulate_ctxt *ctxt) 3591 { 3592 unsigned long val; 3593 3594 if (ctxt->mode == X86EMUL_MODE_PROT64) 3595 val = ctxt->src.val & ~0ULL; 3596 else 3597 val = ctxt->src.val & ~0U; 3598 3599 /* #UD condition is already handled. */ 3600 if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0) 3601 return emulate_gp(ctxt, 0); 3602 3603 /* Disable writeback. */ 3604 ctxt->dst.type = OP_NONE; 3605 return X86EMUL_CONTINUE; 3606 } 3607 3608 static int em_wrmsr(struct x86_emulate_ctxt *ctxt) 3609 { 3610 u64 msr_index = reg_read(ctxt, VCPU_REGS_RCX); 3611 u64 msr_data; 3612 int r; 3613 3614 msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX) 3615 | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32); 3616 r = ctxt->ops->set_msr(ctxt, msr_index, msr_data); 3617 3618 if (r == X86EMUL_IO_NEEDED) 3619 return r; 3620 3621 if (r > 0) 3622 return emulate_gp(ctxt, 0); 3623 3624 return r < 0 ? X86EMUL_UNHANDLEABLE : X86EMUL_CONTINUE; 3625 } 3626 3627 static int em_rdmsr(struct x86_emulate_ctxt *ctxt) 3628 { 3629 u64 msr_index = reg_read(ctxt, VCPU_REGS_RCX); 3630 u64 msr_data; 3631 int r; 3632 3633 r = ctxt->ops->get_msr(ctxt, msr_index, &msr_data); 3634 3635 if (r == X86EMUL_IO_NEEDED) 3636 return r; 3637 3638 if (r) 3639 return emulate_gp(ctxt, 0); 3640 3641 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data; 3642 *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32; 3643 return X86EMUL_CONTINUE; 3644 } 3645 3646 static int em_store_sreg(struct x86_emulate_ctxt *ctxt, int segment) 3647 { 3648 if (segment > VCPU_SREG_GS && 3649 (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && 3650 ctxt->ops->cpl(ctxt) > 0) 3651 return emulate_gp(ctxt, 0); 3652 3653 ctxt->dst.val = get_segment_selector(ctxt, segment); 3654 if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM) 3655 ctxt->dst.bytes = 2; 3656 return X86EMUL_CONTINUE; 3657 } 3658 3659 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt) 3660 { 3661 if (ctxt->modrm_reg > VCPU_SREG_GS) 3662 return emulate_ud(ctxt); 3663 3664 return em_store_sreg(ctxt, ctxt->modrm_reg); 3665 } 3666 3667 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt) 3668 { 3669 u16 sel = ctxt->src.val; 3670 3671 if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS) 3672 return emulate_ud(ctxt); 3673 3674 if (ctxt->modrm_reg == VCPU_SREG_SS) 3675 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; 3676 3677 /* Disable writeback. */ 3678 ctxt->dst.type = OP_NONE; 3679 return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg); 3680 } 3681 3682 static int em_sldt(struct x86_emulate_ctxt *ctxt) 3683 { 3684 return em_store_sreg(ctxt, VCPU_SREG_LDTR); 3685 } 3686 3687 static int em_lldt(struct x86_emulate_ctxt *ctxt) 3688 { 3689 u16 sel = ctxt->src.val; 3690 3691 /* Disable writeback. */ 3692 ctxt->dst.type = OP_NONE; 3693 return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR); 3694 } 3695 3696 static int em_str(struct x86_emulate_ctxt *ctxt) 3697 { 3698 return em_store_sreg(ctxt, VCPU_SREG_TR); 3699 } 3700 3701 static int em_ltr(struct x86_emulate_ctxt *ctxt) 3702 { 3703 u16 sel = ctxt->src.val; 3704 3705 /* Disable writeback. */ 3706 ctxt->dst.type = OP_NONE; 3707 return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR); 3708 } 3709 3710 static int em_invlpg(struct x86_emulate_ctxt *ctxt) 3711 { 3712 int rc; 3713 ulong linear; 3714 3715 rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear); 3716 if (rc == X86EMUL_CONTINUE) 3717 ctxt->ops->invlpg(ctxt, linear); 3718 /* Disable writeback. */ 3719 ctxt->dst.type = OP_NONE; 3720 return X86EMUL_CONTINUE; 3721 } 3722 3723 static int em_clts(struct x86_emulate_ctxt *ctxt) 3724 { 3725 ulong cr0; 3726 3727 cr0 = ctxt->ops->get_cr(ctxt, 0); 3728 cr0 &= ~X86_CR0_TS; 3729 ctxt->ops->set_cr(ctxt, 0, cr0); 3730 return X86EMUL_CONTINUE; 3731 } 3732 3733 static int em_hypercall(struct x86_emulate_ctxt *ctxt) 3734 { 3735 int rc = ctxt->ops->fix_hypercall(ctxt); 3736 3737 if (rc != X86EMUL_CONTINUE) 3738 return rc; 3739 3740 /* Let the processor re-execute the fixed hypercall */ 3741 ctxt->_eip = ctxt->eip; 3742 /* Disable writeback. */ 3743 ctxt->dst.type = OP_NONE; 3744 return X86EMUL_CONTINUE; 3745 } 3746 3747 static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt, 3748 void (*get)(struct x86_emulate_ctxt *ctxt, 3749 struct desc_ptr *ptr)) 3750 { 3751 struct desc_ptr desc_ptr; 3752 3753 if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && 3754 ctxt->ops->cpl(ctxt) > 0) 3755 return emulate_gp(ctxt, 0); 3756 3757 if (ctxt->mode == X86EMUL_MODE_PROT64) 3758 ctxt->op_bytes = 8; 3759 get(ctxt, &desc_ptr); 3760 if (ctxt->op_bytes == 2) { 3761 ctxt->op_bytes = 4; 3762 desc_ptr.address &= 0x00ffffff; 3763 } 3764 /* Disable writeback. */ 3765 ctxt->dst.type = OP_NONE; 3766 return segmented_write_std(ctxt, ctxt->dst.addr.mem, 3767 &desc_ptr, 2 + ctxt->op_bytes); 3768 } 3769 3770 static int em_sgdt(struct x86_emulate_ctxt *ctxt) 3771 { 3772 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt); 3773 } 3774 3775 static int em_sidt(struct x86_emulate_ctxt *ctxt) 3776 { 3777 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt); 3778 } 3779 3780 static int em_lgdt_lidt(struct x86_emulate_ctxt *ctxt, bool lgdt) 3781 { 3782 struct desc_ptr desc_ptr; 3783 int rc; 3784 3785 if (ctxt->mode == X86EMUL_MODE_PROT64) 3786 ctxt->op_bytes = 8; 3787 rc = read_descriptor(ctxt, ctxt->src.addr.mem, 3788 &desc_ptr.size, &desc_ptr.address, 3789 ctxt->op_bytes); 3790 if (rc != X86EMUL_CONTINUE) 3791 return rc; 3792 if (ctxt->mode == X86EMUL_MODE_PROT64 && 3793 emul_is_noncanonical_address(desc_ptr.address, ctxt)) 3794 return emulate_gp(ctxt, 0); 3795 if (lgdt) 3796 ctxt->ops->set_gdt(ctxt, &desc_ptr); 3797 else 3798 ctxt->ops->set_idt(ctxt, &desc_ptr); 3799 /* Disable writeback. */ 3800 ctxt->dst.type = OP_NONE; 3801 return X86EMUL_CONTINUE; 3802 } 3803 3804 static int em_lgdt(struct x86_emulate_ctxt *ctxt) 3805 { 3806 return em_lgdt_lidt(ctxt, true); 3807 } 3808 3809 static int em_lidt(struct x86_emulate_ctxt *ctxt) 3810 { 3811 return em_lgdt_lidt(ctxt, false); 3812 } 3813 3814 static int em_smsw(struct x86_emulate_ctxt *ctxt) 3815 { 3816 if ((ctxt->ops->get_cr(ctxt, 4) & X86_CR4_UMIP) && 3817 ctxt->ops->cpl(ctxt) > 0) 3818 return emulate_gp(ctxt, 0); 3819 3820 if (ctxt->dst.type == OP_MEM) 3821 ctxt->dst.bytes = 2; 3822 ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0); 3823 return X86EMUL_CONTINUE; 3824 } 3825 3826 static int em_lmsw(struct x86_emulate_ctxt *ctxt) 3827 { 3828 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul) 3829 | (ctxt->src.val & 0x0f)); 3830 ctxt->dst.type = OP_NONE; 3831 return X86EMUL_CONTINUE; 3832 } 3833 3834 static int em_loop(struct x86_emulate_ctxt *ctxt) 3835 { 3836 int rc = X86EMUL_CONTINUE; 3837 3838 register_address_increment(ctxt, VCPU_REGS_RCX, -1); 3839 if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) && 3840 (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags))) 3841 rc = jmp_rel(ctxt, ctxt->src.val); 3842 3843 return rc; 3844 } 3845 3846 static int em_jcxz(struct x86_emulate_ctxt *ctxt) 3847 { 3848 int rc = X86EMUL_CONTINUE; 3849 3850 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) 3851 rc = jmp_rel(ctxt, ctxt->src.val); 3852 3853 return rc; 3854 } 3855 3856 static int em_in(struct x86_emulate_ctxt *ctxt) 3857 { 3858 if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val, 3859 &ctxt->dst.val)) 3860 return X86EMUL_IO_NEEDED; 3861 3862 return X86EMUL_CONTINUE; 3863 } 3864 3865 static int em_out(struct x86_emulate_ctxt *ctxt) 3866 { 3867 ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val, 3868 &ctxt->src.val, 1); 3869 /* Disable writeback. */ 3870 ctxt->dst.type = OP_NONE; 3871 return X86EMUL_CONTINUE; 3872 } 3873 3874 static int em_cli(struct x86_emulate_ctxt *ctxt) 3875 { 3876 if (emulator_bad_iopl(ctxt)) 3877 return emulate_gp(ctxt, 0); 3878 3879 ctxt->eflags &= ~X86_EFLAGS_IF; 3880 return X86EMUL_CONTINUE; 3881 } 3882 3883 static int em_sti(struct x86_emulate_ctxt *ctxt) 3884 { 3885 if (emulator_bad_iopl(ctxt)) 3886 return emulate_gp(ctxt, 0); 3887 3888 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; 3889 ctxt->eflags |= X86_EFLAGS_IF; 3890 return X86EMUL_CONTINUE; 3891 } 3892 3893 static int em_cpuid(struct x86_emulate_ctxt *ctxt) 3894 { 3895 u32 eax, ebx, ecx, edx; 3896 u64 msr = 0; 3897 3898 ctxt->ops->get_msr(ctxt, MSR_MISC_FEATURES_ENABLES, &msr); 3899 if (msr & MSR_MISC_FEATURES_ENABLES_CPUID_FAULT && 3900 ctxt->ops->cpl(ctxt)) { 3901 return emulate_gp(ctxt, 0); 3902 } 3903 3904 eax = reg_read(ctxt, VCPU_REGS_RAX); 3905 ecx = reg_read(ctxt, VCPU_REGS_RCX); 3906 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx, false); 3907 *reg_write(ctxt, VCPU_REGS_RAX) = eax; 3908 *reg_write(ctxt, VCPU_REGS_RBX) = ebx; 3909 *reg_write(ctxt, VCPU_REGS_RCX) = ecx; 3910 *reg_write(ctxt, VCPU_REGS_RDX) = edx; 3911 return X86EMUL_CONTINUE; 3912 } 3913 3914 static int em_sahf(struct x86_emulate_ctxt *ctxt) 3915 { 3916 u32 flags; 3917 3918 flags = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | X86_EFLAGS_ZF | 3919 X86_EFLAGS_SF; 3920 flags &= *reg_rmw(ctxt, VCPU_REGS_RAX) >> 8; 3921 3922 ctxt->eflags &= ~0xffUL; 3923 ctxt->eflags |= flags | X86_EFLAGS_FIXED; 3924 return X86EMUL_CONTINUE; 3925 } 3926 3927 static int em_lahf(struct x86_emulate_ctxt *ctxt) 3928 { 3929 *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL; 3930 *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8; 3931 return X86EMUL_CONTINUE; 3932 } 3933 3934 static int em_bswap(struct x86_emulate_ctxt *ctxt) 3935 { 3936 switch (ctxt->op_bytes) { 3937 #ifdef CONFIG_X86_64 3938 case 8: 3939 asm("bswap %0" : "+r"(ctxt->dst.val)); 3940 break; 3941 #endif 3942 default: 3943 asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val)); 3944 break; 3945 } 3946 return X86EMUL_CONTINUE; 3947 } 3948 3949 static int em_clflush(struct x86_emulate_ctxt *ctxt) 3950 { 3951 /* emulating clflush regardless of cpuid */ 3952 return X86EMUL_CONTINUE; 3953 } 3954 3955 static int em_clflushopt(struct x86_emulate_ctxt *ctxt) 3956 { 3957 /* emulating clflushopt regardless of cpuid */ 3958 return X86EMUL_CONTINUE; 3959 } 3960 3961 static int em_movsxd(struct x86_emulate_ctxt *ctxt) 3962 { 3963 ctxt->dst.val = (s32) ctxt->src.val; 3964 return X86EMUL_CONTINUE; 3965 } 3966 3967 static int check_fxsr(struct x86_emulate_ctxt *ctxt) 3968 { 3969 if (!ctxt->ops->guest_has_fxsr(ctxt)) 3970 return emulate_ud(ctxt); 3971 3972 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM)) 3973 return emulate_nm(ctxt); 3974 3975 /* 3976 * Don't emulate a case that should never be hit, instead of working 3977 * around a lack of fxsave64/fxrstor64 on old compilers. 3978 */ 3979 if (ctxt->mode >= X86EMUL_MODE_PROT64) 3980 return X86EMUL_UNHANDLEABLE; 3981 3982 return X86EMUL_CONTINUE; 3983 } 3984 3985 /* 3986 * Hardware doesn't save and restore XMM 0-7 without CR4.OSFXSR, but does save 3987 * and restore MXCSR. 3988 */ 3989 static size_t __fxstate_size(int nregs) 3990 { 3991 return offsetof(struct fxregs_state, xmm_space[0]) + nregs * 16; 3992 } 3993 3994 static inline size_t fxstate_size(struct x86_emulate_ctxt *ctxt) 3995 { 3996 bool cr4_osfxsr; 3997 if (ctxt->mode == X86EMUL_MODE_PROT64) 3998 return __fxstate_size(16); 3999 4000 cr4_osfxsr = ctxt->ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR; 4001 return __fxstate_size(cr4_osfxsr ? 8 : 0); 4002 } 4003 4004 /* 4005 * FXSAVE and FXRSTOR have 4 different formats depending on execution mode, 4006 * 1) 16 bit mode 4007 * 2) 32 bit mode 4008 * - like (1), but FIP and FDP (foo) are only 16 bit. At least Intel CPUs 4009 * preserve whole 32 bit values, though, so (1) and (2) are the same wrt. 4010 * save and restore 4011 * 3) 64-bit mode with REX.W prefix 4012 * - like (2), but XMM 8-15 are being saved and restored 4013 * 4) 64-bit mode without REX.W prefix 4014 * - like (3), but FIP and FDP are 64 bit 4015 * 4016 * Emulation uses (3) for (1) and (2) and preserves XMM 8-15 to reach the 4017 * desired result. (4) is not emulated. 4018 * 4019 * Note: Guest and host CPUID.(EAX=07H,ECX=0H):EBX[bit 13] (deprecate FPU CS 4020 * and FPU DS) should match. 4021 */ 4022 static int em_fxsave(struct x86_emulate_ctxt *ctxt) 4023 { 4024 struct fxregs_state fx_state; 4025 int rc; 4026 4027 rc = check_fxsr(ctxt); 4028 if (rc != X86EMUL_CONTINUE) 4029 return rc; 4030 4031 kvm_fpu_get(); 4032 4033 rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_state)); 4034 4035 kvm_fpu_put(); 4036 4037 if (rc != X86EMUL_CONTINUE) 4038 return rc; 4039 4040 return segmented_write_std(ctxt, ctxt->memop.addr.mem, &fx_state, 4041 fxstate_size(ctxt)); 4042 } 4043 4044 /* 4045 * FXRSTOR might restore XMM registers not provided by the guest. Fill 4046 * in the host registers (via FXSAVE) instead, so they won't be modified. 4047 * (preemption has to stay disabled until FXRSTOR). 4048 * 4049 * Use noinline to keep the stack for other functions called by callers small. 4050 */ 4051 static noinline int fxregs_fixup(struct fxregs_state *fx_state, 4052 const size_t used_size) 4053 { 4054 struct fxregs_state fx_tmp; 4055 int rc; 4056 4057 rc = asm_safe("fxsave %[fx]", , [fx] "+m"(fx_tmp)); 4058 memcpy((void *)fx_state + used_size, (void *)&fx_tmp + used_size, 4059 __fxstate_size(16) - used_size); 4060 4061 return rc; 4062 } 4063 4064 static int em_fxrstor(struct x86_emulate_ctxt *ctxt) 4065 { 4066 struct fxregs_state fx_state; 4067 int rc; 4068 size_t size; 4069 4070 rc = check_fxsr(ctxt); 4071 if (rc != X86EMUL_CONTINUE) 4072 return rc; 4073 4074 size = fxstate_size(ctxt); 4075 rc = segmented_read_std(ctxt, ctxt->memop.addr.mem, &fx_state, size); 4076 if (rc != X86EMUL_CONTINUE) 4077 return rc; 4078 4079 kvm_fpu_get(); 4080 4081 if (size < __fxstate_size(16)) { 4082 rc = fxregs_fixup(&fx_state, size); 4083 if (rc != X86EMUL_CONTINUE) 4084 goto out; 4085 } 4086 4087 if (fx_state.mxcsr >> 16) { 4088 rc = emulate_gp(ctxt, 0); 4089 goto out; 4090 } 4091 4092 if (rc == X86EMUL_CONTINUE) 4093 rc = asm_safe("fxrstor %[fx]", : [fx] "m"(fx_state)); 4094 4095 out: 4096 kvm_fpu_put(); 4097 4098 return rc; 4099 } 4100 4101 static int em_xsetbv(struct x86_emulate_ctxt *ctxt) 4102 { 4103 u32 eax, ecx, edx; 4104 4105 eax = reg_read(ctxt, VCPU_REGS_RAX); 4106 edx = reg_read(ctxt, VCPU_REGS_RDX); 4107 ecx = reg_read(ctxt, VCPU_REGS_RCX); 4108 4109 if (ctxt->ops->set_xcr(ctxt, ecx, ((u64)edx << 32) | eax)) 4110 return emulate_gp(ctxt, 0); 4111 4112 return X86EMUL_CONTINUE; 4113 } 4114 4115 static bool valid_cr(int nr) 4116 { 4117 switch (nr) { 4118 case 0: 4119 case 2 ... 4: 4120 case 8: 4121 return true; 4122 default: 4123 return false; 4124 } 4125 } 4126 4127 static int check_cr_access(struct x86_emulate_ctxt *ctxt) 4128 { 4129 if (!valid_cr(ctxt->modrm_reg)) 4130 return emulate_ud(ctxt); 4131 4132 return X86EMUL_CONTINUE; 4133 } 4134 4135 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt) 4136 { 4137 unsigned long dr7; 4138 4139 ctxt->ops->get_dr(ctxt, 7, &dr7); 4140 4141 /* Check if DR7.Global_Enable is set */ 4142 return dr7 & (1 << 13); 4143 } 4144 4145 static int check_dr_read(struct x86_emulate_ctxt *ctxt) 4146 { 4147 int dr = ctxt->modrm_reg; 4148 u64 cr4; 4149 4150 if (dr > 7) 4151 return emulate_ud(ctxt); 4152 4153 cr4 = ctxt->ops->get_cr(ctxt, 4); 4154 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5)) 4155 return emulate_ud(ctxt); 4156 4157 if (check_dr7_gd(ctxt)) { 4158 ulong dr6; 4159 4160 ctxt->ops->get_dr(ctxt, 6, &dr6); 4161 dr6 &= ~DR_TRAP_BITS; 4162 dr6 |= DR6_BD | DR6_ACTIVE_LOW; 4163 ctxt->ops->set_dr(ctxt, 6, dr6); 4164 return emulate_db(ctxt); 4165 } 4166 4167 return X86EMUL_CONTINUE; 4168 } 4169 4170 static int check_dr_write(struct x86_emulate_ctxt *ctxt) 4171 { 4172 u64 new_val = ctxt->src.val64; 4173 int dr = ctxt->modrm_reg; 4174 4175 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL)) 4176 return emulate_gp(ctxt, 0); 4177 4178 return check_dr_read(ctxt); 4179 } 4180 4181 static int check_svme(struct x86_emulate_ctxt *ctxt) 4182 { 4183 u64 efer = 0; 4184 4185 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 4186 4187 if (!(efer & EFER_SVME)) 4188 return emulate_ud(ctxt); 4189 4190 return X86EMUL_CONTINUE; 4191 } 4192 4193 static int check_svme_pa(struct x86_emulate_ctxt *ctxt) 4194 { 4195 u64 rax = reg_read(ctxt, VCPU_REGS_RAX); 4196 4197 /* Valid physical address? */ 4198 if (rax & 0xffff000000000000ULL) 4199 return emulate_gp(ctxt, 0); 4200 4201 return check_svme(ctxt); 4202 } 4203 4204 static int check_rdtsc(struct x86_emulate_ctxt *ctxt) 4205 { 4206 u64 cr4 = ctxt->ops->get_cr(ctxt, 4); 4207 4208 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt)) 4209 return emulate_ud(ctxt); 4210 4211 return X86EMUL_CONTINUE; 4212 } 4213 4214 static int check_rdpmc(struct x86_emulate_ctxt *ctxt) 4215 { 4216 u64 cr4 = ctxt->ops->get_cr(ctxt, 4); 4217 u64 rcx = reg_read(ctxt, VCPU_REGS_RCX); 4218 4219 /* 4220 * VMware allows access to these Pseduo-PMCs even when read via RDPMC 4221 * in Ring3 when CR4.PCE=0. 4222 */ 4223 if (enable_vmware_backdoor && is_vmware_backdoor_pmc(rcx)) 4224 return X86EMUL_CONTINUE; 4225 4226 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || 4227 ctxt->ops->check_pmc(ctxt, rcx)) 4228 return emulate_gp(ctxt, 0); 4229 4230 return X86EMUL_CONTINUE; 4231 } 4232 4233 static int check_perm_in(struct x86_emulate_ctxt *ctxt) 4234 { 4235 ctxt->dst.bytes = min(ctxt->dst.bytes, 4u); 4236 if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes)) 4237 return emulate_gp(ctxt, 0); 4238 4239 return X86EMUL_CONTINUE; 4240 } 4241 4242 static int check_perm_out(struct x86_emulate_ctxt *ctxt) 4243 { 4244 ctxt->src.bytes = min(ctxt->src.bytes, 4u); 4245 if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes)) 4246 return emulate_gp(ctxt, 0); 4247 4248 return X86EMUL_CONTINUE; 4249 } 4250 4251 #define D(_y) { .flags = (_y) } 4252 #define DI(_y, _i) { .flags = (_y)|Intercept, .intercept = x86_intercept_##_i } 4253 #define DIP(_y, _i, _p) { .flags = (_y)|Intercept|CheckPerm, \ 4254 .intercept = x86_intercept_##_i, .check_perm = (_p) } 4255 #define N D(NotImpl) 4256 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) } 4257 #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) } 4258 #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) } 4259 #define ID(_f, _i) { .flags = ((_f) | InstrDual | ModRM), .u.idual = (_i) } 4260 #define MD(_f, _m) { .flags = ((_f) | ModeDual), .u.mdual = (_m) } 4261 #define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) } 4262 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) } 4263 #define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) } 4264 #define II(_f, _e, _i) \ 4265 { .flags = (_f)|Intercept, .u.execute = (_e), .intercept = x86_intercept_##_i } 4266 #define IIP(_f, _e, _i, _p) \ 4267 { .flags = (_f)|Intercept|CheckPerm, .u.execute = (_e), \ 4268 .intercept = x86_intercept_##_i, .check_perm = (_p) } 4269 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) } 4270 4271 #define D2bv(_f) D((_f) | ByteOp), D(_f) 4272 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p) 4273 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e) 4274 #define F2bv(_f, _e) F((_f) | ByteOp, _e), F(_f, _e) 4275 #define I2bvIP(_f, _e, _i, _p) \ 4276 IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p) 4277 4278 #define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e), \ 4279 F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \ 4280 F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e) 4281 4282 static const struct opcode group7_rm0[] = { 4283 N, 4284 I(SrcNone | Priv | EmulateOnUD, em_hypercall), 4285 N, N, N, N, N, N, 4286 }; 4287 4288 static const struct opcode group7_rm1[] = { 4289 DI(SrcNone | Priv, monitor), 4290 DI(SrcNone | Priv, mwait), 4291 N, N, N, N, N, N, 4292 }; 4293 4294 static const struct opcode group7_rm2[] = { 4295 N, 4296 II(ImplicitOps | Priv, em_xsetbv, xsetbv), 4297 N, N, N, N, N, N, 4298 }; 4299 4300 static const struct opcode group7_rm3[] = { 4301 DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa), 4302 II(SrcNone | Prot | EmulateOnUD, em_hypercall, vmmcall), 4303 DIP(SrcNone | Prot | Priv, vmload, check_svme_pa), 4304 DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa), 4305 DIP(SrcNone | Prot | Priv, stgi, check_svme), 4306 DIP(SrcNone | Prot | Priv, clgi, check_svme), 4307 DIP(SrcNone | Prot | Priv, skinit, check_svme), 4308 DIP(SrcNone | Prot | Priv, invlpga, check_svme), 4309 }; 4310 4311 static const struct opcode group7_rm7[] = { 4312 N, 4313 DIP(SrcNone, rdtscp, check_rdtsc), 4314 N, N, N, N, N, N, 4315 }; 4316 4317 static const struct opcode group1[] = { 4318 F(Lock, em_add), 4319 F(Lock | PageTable, em_or), 4320 F(Lock, em_adc), 4321 F(Lock, em_sbb), 4322 F(Lock | PageTable, em_and), 4323 F(Lock, em_sub), 4324 F(Lock, em_xor), 4325 F(NoWrite, em_cmp), 4326 }; 4327 4328 static const struct opcode group1A[] = { 4329 I(DstMem | SrcNone | Mov | Stack | IncSP | TwoMemOp, em_pop), N, N, N, N, N, N, N, 4330 }; 4331 4332 static const struct opcode group2[] = { 4333 F(DstMem | ModRM, em_rol), 4334 F(DstMem | ModRM, em_ror), 4335 F(DstMem | ModRM, em_rcl), 4336 F(DstMem | ModRM, em_rcr), 4337 F(DstMem | ModRM, em_shl), 4338 F(DstMem | ModRM, em_shr), 4339 F(DstMem | ModRM, em_shl), 4340 F(DstMem | ModRM, em_sar), 4341 }; 4342 4343 static const struct opcode group3[] = { 4344 F(DstMem | SrcImm | NoWrite, em_test), 4345 F(DstMem | SrcImm | NoWrite, em_test), 4346 F(DstMem | SrcNone | Lock, em_not), 4347 F(DstMem | SrcNone | Lock, em_neg), 4348 F(DstXacc | Src2Mem, em_mul_ex), 4349 F(DstXacc | Src2Mem, em_imul_ex), 4350 F(DstXacc | Src2Mem, em_div_ex), 4351 F(DstXacc | Src2Mem, em_idiv_ex), 4352 }; 4353 4354 static const struct opcode group4[] = { 4355 F(ByteOp | DstMem | SrcNone | Lock, em_inc), 4356 F(ByteOp | DstMem | SrcNone | Lock, em_dec), 4357 N, N, N, N, N, N, 4358 }; 4359 4360 static const struct opcode group5[] = { 4361 F(DstMem | SrcNone | Lock, em_inc), 4362 F(DstMem | SrcNone | Lock, em_dec), 4363 I(SrcMem | NearBranch, em_call_near_abs), 4364 I(SrcMemFAddr | ImplicitOps, em_call_far), 4365 I(SrcMem | NearBranch, em_jmp_abs), 4366 I(SrcMemFAddr | ImplicitOps, em_jmp_far), 4367 I(SrcMem | Stack | TwoMemOp, em_push), D(Undefined), 4368 }; 4369 4370 static const struct opcode group6[] = { 4371 II(Prot | DstMem, em_sldt, sldt), 4372 II(Prot | DstMem, em_str, str), 4373 II(Prot | Priv | SrcMem16, em_lldt, lldt), 4374 II(Prot | Priv | SrcMem16, em_ltr, ltr), 4375 N, N, N, N, 4376 }; 4377 4378 static const struct group_dual group7 = { { 4379 II(Mov | DstMem, em_sgdt, sgdt), 4380 II(Mov | DstMem, em_sidt, sidt), 4381 II(SrcMem | Priv, em_lgdt, lgdt), 4382 II(SrcMem | Priv, em_lidt, lidt), 4383 II(SrcNone | DstMem | Mov, em_smsw, smsw), N, 4384 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), 4385 II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg), 4386 }, { 4387 EXT(0, group7_rm0), 4388 EXT(0, group7_rm1), 4389 EXT(0, group7_rm2), 4390 EXT(0, group7_rm3), 4391 II(SrcNone | DstMem | Mov, em_smsw, smsw), N, 4392 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw), 4393 EXT(0, group7_rm7), 4394 } }; 4395 4396 static const struct opcode group8[] = { 4397 N, N, N, N, 4398 F(DstMem | SrcImmByte | NoWrite, em_bt), 4399 F(DstMem | SrcImmByte | Lock | PageTable, em_bts), 4400 F(DstMem | SrcImmByte | Lock, em_btr), 4401 F(DstMem | SrcImmByte | Lock | PageTable, em_btc), 4402 }; 4403 4404 /* 4405 * The "memory" destination is actually always a register, since we come 4406 * from the register case of group9. 4407 */ 4408 static const struct gprefix pfx_0f_c7_7 = { 4409 N, N, N, II(DstMem | ModRM | Op3264 | EmulateOnUD, em_rdpid, rdpid), 4410 }; 4411 4412 4413 static const struct group_dual group9 = { { 4414 N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N, 4415 }, { 4416 N, N, N, N, N, N, N, 4417 GP(0, &pfx_0f_c7_7), 4418 } }; 4419 4420 static const struct opcode group11[] = { 4421 I(DstMem | SrcImm | Mov | PageTable, em_mov), 4422 X7(D(Undefined)), 4423 }; 4424 4425 static const struct gprefix pfx_0f_ae_7 = { 4426 I(SrcMem | ByteOp, em_clflush), I(SrcMem | ByteOp, em_clflushopt), N, N, 4427 }; 4428 4429 static const struct group_dual group15 = { { 4430 I(ModRM | Aligned16, em_fxsave), 4431 I(ModRM | Aligned16, em_fxrstor), 4432 N, N, N, N, N, GP(0, &pfx_0f_ae_7), 4433 }, { 4434 N, N, N, N, N, N, N, N, 4435 } }; 4436 4437 static const struct gprefix pfx_0f_6f_0f_7f = { 4438 I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov), 4439 }; 4440 4441 static const struct instr_dual instr_dual_0f_2b = { 4442 I(0, em_mov), N 4443 }; 4444 4445 static const struct gprefix pfx_0f_2b = { 4446 ID(0, &instr_dual_0f_2b), ID(0, &instr_dual_0f_2b), N, N, 4447 }; 4448 4449 static const struct gprefix pfx_0f_10_0f_11 = { 4450 I(Unaligned, em_mov), I(Unaligned, em_mov), N, N, 4451 }; 4452 4453 static const struct gprefix pfx_0f_28_0f_29 = { 4454 I(Aligned, em_mov), I(Aligned, em_mov), N, N, 4455 }; 4456 4457 static const struct gprefix pfx_0f_e7 = { 4458 N, I(Sse, em_mov), N, N, 4459 }; 4460 4461 static const struct escape escape_d9 = { { 4462 N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstcw), 4463 }, { 4464 /* 0xC0 - 0xC7 */ 4465 N, N, N, N, N, N, N, N, 4466 /* 0xC8 - 0xCF */ 4467 N, N, N, N, N, N, N, N, 4468 /* 0xD0 - 0xC7 */ 4469 N, N, N, N, N, N, N, N, 4470 /* 0xD8 - 0xDF */ 4471 N, N, N, N, N, N, N, N, 4472 /* 0xE0 - 0xE7 */ 4473 N, N, N, N, N, N, N, N, 4474 /* 0xE8 - 0xEF */ 4475 N, N, N, N, N, N, N, N, 4476 /* 0xF0 - 0xF7 */ 4477 N, N, N, N, N, N, N, N, 4478 /* 0xF8 - 0xFF */ 4479 N, N, N, N, N, N, N, N, 4480 } }; 4481 4482 static const struct escape escape_db = { { 4483 N, N, N, N, N, N, N, N, 4484 }, { 4485 /* 0xC0 - 0xC7 */ 4486 N, N, N, N, N, N, N, N, 4487 /* 0xC8 - 0xCF */ 4488 N, N, N, N, N, N, N, N, 4489 /* 0xD0 - 0xC7 */ 4490 N, N, N, N, N, N, N, N, 4491 /* 0xD8 - 0xDF */ 4492 N, N, N, N, N, N, N, N, 4493 /* 0xE0 - 0xE7 */ 4494 N, N, N, I(ImplicitOps, em_fninit), N, N, N, N, 4495 /* 0xE8 - 0xEF */ 4496 N, N, N, N, N, N, N, N, 4497 /* 0xF0 - 0xF7 */ 4498 N, N, N, N, N, N, N, N, 4499 /* 0xF8 - 0xFF */ 4500 N, N, N, N, N, N, N, N, 4501 } }; 4502 4503 static const struct escape escape_dd = { { 4504 N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstsw), 4505 }, { 4506 /* 0xC0 - 0xC7 */ 4507 N, N, N, N, N, N, N, N, 4508 /* 0xC8 - 0xCF */ 4509 N, N, N, N, N, N, N, N, 4510 /* 0xD0 - 0xC7 */ 4511 N, N, N, N, N, N, N, N, 4512 /* 0xD8 - 0xDF */ 4513 N, N, N, N, N, N, N, N, 4514 /* 0xE0 - 0xE7 */ 4515 N, N, N, N, N, N, N, N, 4516 /* 0xE8 - 0xEF */ 4517 N, N, N, N, N, N, N, N, 4518 /* 0xF0 - 0xF7 */ 4519 N, N, N, N, N, N, N, N, 4520 /* 0xF8 - 0xFF */ 4521 N, N, N, N, N, N, N, N, 4522 } }; 4523 4524 static const struct instr_dual instr_dual_0f_c3 = { 4525 I(DstMem | SrcReg | ModRM | No16 | Mov, em_mov), N 4526 }; 4527 4528 static const struct mode_dual mode_dual_63 = { 4529 N, I(DstReg | SrcMem32 | ModRM | Mov, em_movsxd) 4530 }; 4531 4532 static const struct opcode opcode_table[256] = { 4533 /* 0x00 - 0x07 */ 4534 F6ALU(Lock, em_add), 4535 I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg), 4536 I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg), 4537 /* 0x08 - 0x0F */ 4538 F6ALU(Lock | PageTable, em_or), 4539 I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg), 4540 N, 4541 /* 0x10 - 0x17 */ 4542 F6ALU(Lock, em_adc), 4543 I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg), 4544 I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg), 4545 /* 0x18 - 0x1F */ 4546 F6ALU(Lock, em_sbb), 4547 I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg), 4548 I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg), 4549 /* 0x20 - 0x27 */ 4550 F6ALU(Lock | PageTable, em_and), N, N, 4551 /* 0x28 - 0x2F */ 4552 F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das), 4553 /* 0x30 - 0x37 */ 4554 F6ALU(Lock, em_xor), N, N, 4555 /* 0x38 - 0x3F */ 4556 F6ALU(NoWrite, em_cmp), N, N, 4557 /* 0x40 - 0x4F */ 4558 X8(F(DstReg, em_inc)), X8(F(DstReg, em_dec)), 4559 /* 0x50 - 0x57 */ 4560 X8(I(SrcReg | Stack, em_push)), 4561 /* 0x58 - 0x5F */ 4562 X8(I(DstReg | Stack, em_pop)), 4563 /* 0x60 - 0x67 */ 4564 I(ImplicitOps | Stack | No64, em_pusha), 4565 I(ImplicitOps | Stack | No64, em_popa), 4566 N, MD(ModRM, &mode_dual_63), 4567 N, N, N, N, 4568 /* 0x68 - 0x6F */ 4569 I(SrcImm | Mov | Stack, em_push), 4570 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op), 4571 I(SrcImmByte | Mov | Stack, em_push), 4572 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op), 4573 I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */ 4574 I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */ 4575 /* 0x70 - 0x7F */ 4576 X16(D(SrcImmByte | NearBranch)), 4577 /* 0x80 - 0x87 */ 4578 G(ByteOp | DstMem | SrcImm, group1), 4579 G(DstMem | SrcImm, group1), 4580 G(ByteOp | DstMem | SrcImm | No64, group1), 4581 G(DstMem | SrcImmByte, group1), 4582 F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test), 4583 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg), 4584 /* 0x88 - 0x8F */ 4585 I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov), 4586 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov), 4587 I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg), 4588 D(ModRM | SrcMem | NoAccess | DstReg), 4589 I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm), 4590 G(0, group1A), 4591 /* 0x90 - 0x97 */ 4592 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)), 4593 /* 0x98 - 0x9F */ 4594 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd), 4595 I(SrcImmFAddr | No64, em_call_far), N, 4596 II(ImplicitOps | Stack, em_pushf, pushf), 4597 II(ImplicitOps | Stack, em_popf, popf), 4598 I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf), 4599 /* 0xA0 - 0xA7 */ 4600 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov), 4601 I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov), 4602 I2bv(SrcSI | DstDI | Mov | String | TwoMemOp, em_mov), 4603 F2bv(SrcSI | DstDI | String | NoWrite | TwoMemOp, em_cmp_r), 4604 /* 0xA8 - 0xAF */ 4605 F2bv(DstAcc | SrcImm | NoWrite, em_test), 4606 I2bv(SrcAcc | DstDI | Mov | String, em_mov), 4607 I2bv(SrcSI | DstAcc | Mov | String, em_mov), 4608 F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r), 4609 /* 0xB0 - 0xB7 */ 4610 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)), 4611 /* 0xB8 - 0xBF */ 4612 X8(I(DstReg | SrcImm64 | Mov, em_mov)), 4613 /* 0xC0 - 0xC7 */ 4614 G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2), 4615 I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm), 4616 I(ImplicitOps | NearBranch, em_ret), 4617 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg), 4618 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg), 4619 G(ByteOp, group11), G(0, group11), 4620 /* 0xC8 - 0xCF */ 4621 I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave), 4622 I(ImplicitOps | SrcImmU16, em_ret_far_imm), 4623 I(ImplicitOps, em_ret_far), 4624 D(ImplicitOps), DI(SrcImmByte, intn), 4625 D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret), 4626 /* 0xD0 - 0xD7 */ 4627 G(Src2One | ByteOp, group2), G(Src2One, group2), 4628 G(Src2CL | ByteOp, group2), G(Src2CL, group2), 4629 I(DstAcc | SrcImmUByte | No64, em_aam), 4630 I(DstAcc | SrcImmUByte | No64, em_aad), 4631 F(DstAcc | ByteOp | No64, em_salc), 4632 I(DstAcc | SrcXLat | ByteOp, em_mov), 4633 /* 0xD8 - 0xDF */ 4634 N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N, 4635 /* 0xE0 - 0xE7 */ 4636 X3(I(SrcImmByte | NearBranch, em_loop)), 4637 I(SrcImmByte | NearBranch, em_jcxz), 4638 I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in), 4639 I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out), 4640 /* 0xE8 - 0xEF */ 4641 I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps | NearBranch), 4642 I(SrcImmFAddr | No64, em_jmp_far), 4643 D(SrcImmByte | ImplicitOps | NearBranch), 4644 I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in), 4645 I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out), 4646 /* 0xF0 - 0xF7 */ 4647 N, DI(ImplicitOps, icebp), N, N, 4648 DI(ImplicitOps | Priv, hlt), D(ImplicitOps), 4649 G(ByteOp, group3), G(0, group3), 4650 /* 0xF8 - 0xFF */ 4651 D(ImplicitOps), D(ImplicitOps), 4652 I(ImplicitOps, em_cli), I(ImplicitOps, em_sti), 4653 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5), 4654 }; 4655 4656 static const struct opcode twobyte_table[256] = { 4657 /* 0x00 - 0x0F */ 4658 G(0, group6), GD(0, &group7), N, N, 4659 N, I(ImplicitOps | EmulateOnUD, em_syscall), 4660 II(ImplicitOps | Priv, em_clts, clts), N, 4661 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N, 4662 N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N, 4663 /* 0x10 - 0x1F */ 4664 GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_10_0f_11), 4665 GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_10_0f_11), 4666 N, N, N, N, N, N, 4667 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 4 * prefetch + 4 * reserved NOP */ 4668 D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N, 4669 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */ 4670 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */ 4671 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* 8 * reserved NOP */ 4672 D(ImplicitOps | ModRM | SrcMem | NoAccess), /* NOP + 7 * reserved NOP */ 4673 /* 0x20 - 0x2F */ 4674 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_access), 4675 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read), 4676 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_cr_write, cr_write, 4677 check_cr_access), 4678 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_dr_write, dr_write, 4679 check_dr_write), 4680 N, N, N, N, 4681 GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_28_0f_29), 4682 GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_28_0f_29), 4683 N, GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_2b), 4684 N, N, N, N, 4685 /* 0x30 - 0x3F */ 4686 II(ImplicitOps | Priv, em_wrmsr, wrmsr), 4687 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc), 4688 II(ImplicitOps | Priv, em_rdmsr, rdmsr), 4689 IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc), 4690 I(ImplicitOps | EmulateOnUD, em_sysenter), 4691 I(ImplicitOps | Priv | EmulateOnUD, em_sysexit), 4692 N, N, 4693 N, N, N, N, N, N, N, N, 4694 /* 0x40 - 0x4F */ 4695 X16(D(DstReg | SrcMem | ModRM)), 4696 /* 0x50 - 0x5F */ 4697 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 4698 /* 0x60 - 0x6F */ 4699 N, N, N, N, 4700 N, N, N, N, 4701 N, N, N, N, 4702 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f), 4703 /* 0x70 - 0x7F */ 4704 N, N, N, N, 4705 N, N, N, N, 4706 N, N, N, N, 4707 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f), 4708 /* 0x80 - 0x8F */ 4709 X16(D(SrcImm | NearBranch)), 4710 /* 0x90 - 0x9F */ 4711 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)), 4712 /* 0xA0 - 0xA7 */ 4713 I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg), 4714 II(ImplicitOps, em_cpuid, cpuid), 4715 F(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt), 4716 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld), 4717 F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N, 4718 /* 0xA8 - 0xAF */ 4719 I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg), 4720 II(EmulateOnUD | ImplicitOps, em_rsm, rsm), 4721 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts), 4722 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd), 4723 F(DstMem | SrcReg | Src2CL | ModRM, em_shrd), 4724 GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul), 4725 /* 0xB0 - 0xB7 */ 4726 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable | SrcWrite, em_cmpxchg), 4727 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg), 4728 F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr), 4729 I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg), 4730 I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg), 4731 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), 4732 /* 0xB8 - 0xBF */ 4733 N, N, 4734 G(BitOp, group8), 4735 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc), 4736 I(DstReg | SrcMem | ModRM, em_bsf_c), 4737 I(DstReg | SrcMem | ModRM, em_bsr_c), 4738 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), 4739 /* 0xC0 - 0xC7 */ 4740 F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd), 4741 N, ID(0, &instr_dual_0f_c3), 4742 N, N, N, GD(0, &group9), 4743 /* 0xC8 - 0xCF */ 4744 X8(I(DstReg, em_bswap)), 4745 /* 0xD0 - 0xDF */ 4746 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 4747 /* 0xE0 - 0xEF */ 4748 N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_e7), 4749 N, N, N, N, N, N, N, N, 4750 /* 0xF0 - 0xFF */ 4751 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N 4752 }; 4753 4754 static const struct instr_dual instr_dual_0f_38_f0 = { 4755 I(DstReg | SrcMem | Mov, em_movbe), N 4756 }; 4757 4758 static const struct instr_dual instr_dual_0f_38_f1 = { 4759 I(DstMem | SrcReg | Mov, em_movbe), N 4760 }; 4761 4762 static const struct gprefix three_byte_0f_38_f0 = { 4763 ID(0, &instr_dual_0f_38_f0), N, N, N 4764 }; 4765 4766 static const struct gprefix three_byte_0f_38_f1 = { 4767 ID(0, &instr_dual_0f_38_f1), N, N, N 4768 }; 4769 4770 /* 4771 * Insns below are selected by the prefix which indexed by the third opcode 4772 * byte. 4773 */ 4774 static const struct opcode opcode_map_0f_38[256] = { 4775 /* 0x00 - 0x7f */ 4776 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), 4777 /* 0x80 - 0xef */ 4778 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), 4779 /* 0xf0 - 0xf1 */ 4780 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f0), 4781 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f1), 4782 /* 0xf2 - 0xff */ 4783 N, N, X4(N), X8(N) 4784 }; 4785 4786 #undef D 4787 #undef N 4788 #undef G 4789 #undef GD 4790 #undef I 4791 #undef GP 4792 #undef EXT 4793 #undef MD 4794 #undef ID 4795 4796 #undef D2bv 4797 #undef D2bvIP 4798 #undef I2bv 4799 #undef I2bvIP 4800 #undef I6ALU 4801 4802 static unsigned imm_size(struct x86_emulate_ctxt *ctxt) 4803 { 4804 unsigned size; 4805 4806 size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4807 if (size == 8) 4808 size = 4; 4809 return size; 4810 } 4811 4812 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op, 4813 unsigned size, bool sign_extension) 4814 { 4815 int rc = X86EMUL_CONTINUE; 4816 4817 op->type = OP_IMM; 4818 op->bytes = size; 4819 op->addr.mem.ea = ctxt->_eip; 4820 /* NB. Immediates are sign-extended as necessary. */ 4821 switch (op->bytes) { 4822 case 1: 4823 op->val = insn_fetch(s8, ctxt); 4824 break; 4825 case 2: 4826 op->val = insn_fetch(s16, ctxt); 4827 break; 4828 case 4: 4829 op->val = insn_fetch(s32, ctxt); 4830 break; 4831 case 8: 4832 op->val = insn_fetch(s64, ctxt); 4833 break; 4834 } 4835 if (!sign_extension) { 4836 switch (op->bytes) { 4837 case 1: 4838 op->val &= 0xff; 4839 break; 4840 case 2: 4841 op->val &= 0xffff; 4842 break; 4843 case 4: 4844 op->val &= 0xffffffff; 4845 break; 4846 } 4847 } 4848 done: 4849 return rc; 4850 } 4851 4852 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op, 4853 unsigned d) 4854 { 4855 int rc = X86EMUL_CONTINUE; 4856 4857 switch (d) { 4858 case OpReg: 4859 decode_register_operand(ctxt, op); 4860 break; 4861 case OpImmUByte: 4862 rc = decode_imm(ctxt, op, 1, false); 4863 break; 4864 case OpMem: 4865 ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4866 mem_common: 4867 *op = ctxt->memop; 4868 ctxt->memopp = op; 4869 if (ctxt->d & BitOp) 4870 fetch_bit_operand(ctxt); 4871 op->orig_val = op->val; 4872 break; 4873 case OpMem64: 4874 ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8; 4875 goto mem_common; 4876 case OpAcc: 4877 op->type = OP_REG; 4878 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4879 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); 4880 fetch_register_operand(op); 4881 op->orig_val = op->val; 4882 break; 4883 case OpAccLo: 4884 op->type = OP_REG; 4885 op->bytes = (ctxt->d & ByteOp) ? 2 : ctxt->op_bytes; 4886 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX); 4887 fetch_register_operand(op); 4888 op->orig_val = op->val; 4889 break; 4890 case OpAccHi: 4891 if (ctxt->d & ByteOp) { 4892 op->type = OP_NONE; 4893 break; 4894 } 4895 op->type = OP_REG; 4896 op->bytes = ctxt->op_bytes; 4897 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); 4898 fetch_register_operand(op); 4899 op->orig_val = op->val; 4900 break; 4901 case OpDI: 4902 op->type = OP_MEM; 4903 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4904 op->addr.mem.ea = 4905 register_address(ctxt, VCPU_REGS_RDI); 4906 op->addr.mem.seg = VCPU_SREG_ES; 4907 op->val = 0; 4908 op->count = 1; 4909 break; 4910 case OpDX: 4911 op->type = OP_REG; 4912 op->bytes = 2; 4913 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX); 4914 fetch_register_operand(op); 4915 break; 4916 case OpCL: 4917 op->type = OP_IMM; 4918 op->bytes = 1; 4919 op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff; 4920 break; 4921 case OpImmByte: 4922 rc = decode_imm(ctxt, op, 1, true); 4923 break; 4924 case OpOne: 4925 op->type = OP_IMM; 4926 op->bytes = 1; 4927 op->val = 1; 4928 break; 4929 case OpImm: 4930 rc = decode_imm(ctxt, op, imm_size(ctxt), true); 4931 break; 4932 case OpImm64: 4933 rc = decode_imm(ctxt, op, ctxt->op_bytes, true); 4934 break; 4935 case OpMem8: 4936 ctxt->memop.bytes = 1; 4937 if (ctxt->memop.type == OP_REG) { 4938 ctxt->memop.addr.reg = decode_register(ctxt, 4939 ctxt->modrm_rm, true); 4940 fetch_register_operand(&ctxt->memop); 4941 } 4942 goto mem_common; 4943 case OpMem16: 4944 ctxt->memop.bytes = 2; 4945 goto mem_common; 4946 case OpMem32: 4947 ctxt->memop.bytes = 4; 4948 goto mem_common; 4949 case OpImmU16: 4950 rc = decode_imm(ctxt, op, 2, false); 4951 break; 4952 case OpImmU: 4953 rc = decode_imm(ctxt, op, imm_size(ctxt), false); 4954 break; 4955 case OpSI: 4956 op->type = OP_MEM; 4957 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4958 op->addr.mem.ea = 4959 register_address(ctxt, VCPU_REGS_RSI); 4960 op->addr.mem.seg = ctxt->seg_override; 4961 op->val = 0; 4962 op->count = 1; 4963 break; 4964 case OpXLat: 4965 op->type = OP_MEM; 4966 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; 4967 op->addr.mem.ea = 4968 address_mask(ctxt, 4969 reg_read(ctxt, VCPU_REGS_RBX) + 4970 (reg_read(ctxt, VCPU_REGS_RAX) & 0xff)); 4971 op->addr.mem.seg = ctxt->seg_override; 4972 op->val = 0; 4973 break; 4974 case OpImmFAddr: 4975 op->type = OP_IMM; 4976 op->addr.mem.ea = ctxt->_eip; 4977 op->bytes = ctxt->op_bytes + 2; 4978 insn_fetch_arr(op->valptr, op->bytes, ctxt); 4979 break; 4980 case OpMemFAddr: 4981 ctxt->memop.bytes = ctxt->op_bytes + 2; 4982 goto mem_common; 4983 case OpES: 4984 op->type = OP_IMM; 4985 op->val = VCPU_SREG_ES; 4986 break; 4987 case OpCS: 4988 op->type = OP_IMM; 4989 op->val = VCPU_SREG_CS; 4990 break; 4991 case OpSS: 4992 op->type = OP_IMM; 4993 op->val = VCPU_SREG_SS; 4994 break; 4995 case OpDS: 4996 op->type = OP_IMM; 4997 op->val = VCPU_SREG_DS; 4998 break; 4999 case OpFS: 5000 op->type = OP_IMM; 5001 op->val = VCPU_SREG_FS; 5002 break; 5003 case OpGS: 5004 op->type = OP_IMM; 5005 op->val = VCPU_SREG_GS; 5006 break; 5007 case OpImplicit: 5008 /* Special instructions do their own operand decoding. */ 5009 default: 5010 op->type = OP_NONE; /* Disable writeback. */ 5011 break; 5012 } 5013 5014 done: 5015 return rc; 5016 } 5017 5018 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int emulation_type) 5019 { 5020 int rc = X86EMUL_CONTINUE; 5021 int mode = ctxt->mode; 5022 int def_op_bytes, def_ad_bytes, goffset, simd_prefix; 5023 bool op_prefix = false; 5024 bool has_seg_override = false; 5025 struct opcode opcode; 5026 u16 dummy; 5027 struct desc_struct desc; 5028 5029 ctxt->memop.type = OP_NONE; 5030 ctxt->memopp = NULL; 5031 ctxt->_eip = ctxt->eip; 5032 ctxt->fetch.ptr = ctxt->fetch.data; 5033 ctxt->fetch.end = ctxt->fetch.data + insn_len; 5034 ctxt->opcode_len = 1; 5035 ctxt->intercept = x86_intercept_none; 5036 if (insn_len > 0) 5037 memcpy(ctxt->fetch.data, insn, insn_len); 5038 else { 5039 rc = __do_insn_fetch_bytes(ctxt, 1); 5040 if (rc != X86EMUL_CONTINUE) 5041 goto done; 5042 } 5043 5044 switch (mode) { 5045 case X86EMUL_MODE_REAL: 5046 case X86EMUL_MODE_VM86: 5047 def_op_bytes = def_ad_bytes = 2; 5048 ctxt->ops->get_segment(ctxt, &dummy, &desc, NULL, VCPU_SREG_CS); 5049 if (desc.d) 5050 def_op_bytes = def_ad_bytes = 4; 5051 break; 5052 case X86EMUL_MODE_PROT16: 5053 def_op_bytes = def_ad_bytes = 2; 5054 break; 5055 case X86EMUL_MODE_PROT32: 5056 def_op_bytes = def_ad_bytes = 4; 5057 break; 5058 #ifdef CONFIG_X86_64 5059 case X86EMUL_MODE_PROT64: 5060 def_op_bytes = 4; 5061 def_ad_bytes = 8; 5062 break; 5063 #endif 5064 default: 5065 return EMULATION_FAILED; 5066 } 5067 5068 ctxt->op_bytes = def_op_bytes; 5069 ctxt->ad_bytes = def_ad_bytes; 5070 5071 /* Legacy prefixes. */ 5072 for (;;) { 5073 switch (ctxt->b = insn_fetch(u8, ctxt)) { 5074 case 0x66: /* operand-size override */ 5075 op_prefix = true; 5076 /* switch between 2/4 bytes */ 5077 ctxt->op_bytes = def_op_bytes ^ 6; 5078 break; 5079 case 0x67: /* address-size override */ 5080 if (mode == X86EMUL_MODE_PROT64) 5081 /* switch between 4/8 bytes */ 5082 ctxt->ad_bytes = def_ad_bytes ^ 12; 5083 else 5084 /* switch between 2/4 bytes */ 5085 ctxt->ad_bytes = def_ad_bytes ^ 6; 5086 break; 5087 case 0x26: /* ES override */ 5088 has_seg_override = true; 5089 ctxt->seg_override = VCPU_SREG_ES; 5090 break; 5091 case 0x2e: /* CS override */ 5092 has_seg_override = true; 5093 ctxt->seg_override = VCPU_SREG_CS; 5094 break; 5095 case 0x36: /* SS override */ 5096 has_seg_override = true; 5097 ctxt->seg_override = VCPU_SREG_SS; 5098 break; 5099 case 0x3e: /* DS override */ 5100 has_seg_override = true; 5101 ctxt->seg_override = VCPU_SREG_DS; 5102 break; 5103 case 0x64: /* FS override */ 5104 has_seg_override = true; 5105 ctxt->seg_override = VCPU_SREG_FS; 5106 break; 5107 case 0x65: /* GS override */ 5108 has_seg_override = true; 5109 ctxt->seg_override = VCPU_SREG_GS; 5110 break; 5111 case 0x40 ... 0x4f: /* REX */ 5112 if (mode != X86EMUL_MODE_PROT64) 5113 goto done_prefixes; 5114 ctxt->rex_prefix = ctxt->b; 5115 continue; 5116 case 0xf0: /* LOCK */ 5117 ctxt->lock_prefix = 1; 5118 break; 5119 case 0xf2: /* REPNE/REPNZ */ 5120 case 0xf3: /* REP/REPE/REPZ */ 5121 ctxt->rep_prefix = ctxt->b; 5122 break; 5123 default: 5124 goto done_prefixes; 5125 } 5126 5127 /* Any legacy prefix after a REX prefix nullifies its effect. */ 5128 5129 ctxt->rex_prefix = 0; 5130 } 5131 5132 done_prefixes: 5133 5134 /* REX prefix. */ 5135 if (ctxt->rex_prefix & 8) 5136 ctxt->op_bytes = 8; /* REX.W */ 5137 5138 /* Opcode byte(s). */ 5139 opcode = opcode_table[ctxt->b]; 5140 /* Two-byte opcode? */ 5141 if (ctxt->b == 0x0f) { 5142 ctxt->opcode_len = 2; 5143 ctxt->b = insn_fetch(u8, ctxt); 5144 opcode = twobyte_table[ctxt->b]; 5145 5146 /* 0F_38 opcode map */ 5147 if (ctxt->b == 0x38) { 5148 ctxt->opcode_len = 3; 5149 ctxt->b = insn_fetch(u8, ctxt); 5150 opcode = opcode_map_0f_38[ctxt->b]; 5151 } 5152 } 5153 ctxt->d = opcode.flags; 5154 5155 if (ctxt->d & ModRM) 5156 ctxt->modrm = insn_fetch(u8, ctxt); 5157 5158 /* vex-prefix instructions are not implemented */ 5159 if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) && 5160 (mode == X86EMUL_MODE_PROT64 || (ctxt->modrm & 0xc0) == 0xc0)) { 5161 ctxt->d = NotImpl; 5162 } 5163 5164 while (ctxt->d & GroupMask) { 5165 switch (ctxt->d & GroupMask) { 5166 case Group: 5167 goffset = (ctxt->modrm >> 3) & 7; 5168 opcode = opcode.u.group[goffset]; 5169 break; 5170 case GroupDual: 5171 goffset = (ctxt->modrm >> 3) & 7; 5172 if ((ctxt->modrm >> 6) == 3) 5173 opcode = opcode.u.gdual->mod3[goffset]; 5174 else 5175 opcode = opcode.u.gdual->mod012[goffset]; 5176 break; 5177 case RMExt: 5178 goffset = ctxt->modrm & 7; 5179 opcode = opcode.u.group[goffset]; 5180 break; 5181 case Prefix: 5182 if (ctxt->rep_prefix && op_prefix) 5183 return EMULATION_FAILED; 5184 simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix; 5185 switch (simd_prefix) { 5186 case 0x00: opcode = opcode.u.gprefix->pfx_no; break; 5187 case 0x66: opcode = opcode.u.gprefix->pfx_66; break; 5188 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break; 5189 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break; 5190 } 5191 break; 5192 case Escape: 5193 if (ctxt->modrm > 0xbf) { 5194 size_t size = ARRAY_SIZE(opcode.u.esc->high); 5195 u32 index = array_index_nospec( 5196 ctxt->modrm - 0xc0, size); 5197 5198 opcode = opcode.u.esc->high[index]; 5199 } else { 5200 opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7]; 5201 } 5202 break; 5203 case InstrDual: 5204 if ((ctxt->modrm >> 6) == 3) 5205 opcode = opcode.u.idual->mod3; 5206 else 5207 opcode = opcode.u.idual->mod012; 5208 break; 5209 case ModeDual: 5210 if (ctxt->mode == X86EMUL_MODE_PROT64) 5211 opcode = opcode.u.mdual->mode64; 5212 else 5213 opcode = opcode.u.mdual->mode32; 5214 break; 5215 default: 5216 return EMULATION_FAILED; 5217 } 5218 5219 ctxt->d &= ~(u64)GroupMask; 5220 ctxt->d |= opcode.flags; 5221 } 5222 5223 /* Unrecognised? */ 5224 if (ctxt->d == 0) 5225 return EMULATION_FAILED; 5226 5227 ctxt->execute = opcode.u.execute; 5228 5229 if (unlikely(emulation_type & EMULTYPE_TRAP_UD) && 5230 likely(!(ctxt->d & EmulateOnUD))) 5231 return EMULATION_FAILED; 5232 5233 if (unlikely(ctxt->d & 5234 (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch| 5235 No16))) { 5236 /* 5237 * These are copied unconditionally here, and checked unconditionally 5238 * in x86_emulate_insn. 5239 */ 5240 ctxt->check_perm = opcode.check_perm; 5241 ctxt->intercept = opcode.intercept; 5242 5243 if (ctxt->d & NotImpl) 5244 return EMULATION_FAILED; 5245 5246 if (mode == X86EMUL_MODE_PROT64) { 5247 if (ctxt->op_bytes == 4 && (ctxt->d & Stack)) 5248 ctxt->op_bytes = 8; 5249 else if (ctxt->d & NearBranch) 5250 ctxt->op_bytes = 8; 5251 } 5252 5253 if (ctxt->d & Op3264) { 5254 if (mode == X86EMUL_MODE_PROT64) 5255 ctxt->op_bytes = 8; 5256 else 5257 ctxt->op_bytes = 4; 5258 } 5259 5260 if ((ctxt->d & No16) && ctxt->op_bytes == 2) 5261 ctxt->op_bytes = 4; 5262 5263 if (ctxt->d & Sse) 5264 ctxt->op_bytes = 16; 5265 else if (ctxt->d & Mmx) 5266 ctxt->op_bytes = 8; 5267 } 5268 5269 /* ModRM and SIB bytes. */ 5270 if (ctxt->d & ModRM) { 5271 rc = decode_modrm(ctxt, &ctxt->memop); 5272 if (!has_seg_override) { 5273 has_seg_override = true; 5274 ctxt->seg_override = ctxt->modrm_seg; 5275 } 5276 } else if (ctxt->d & MemAbs) 5277 rc = decode_abs(ctxt, &ctxt->memop); 5278 if (rc != X86EMUL_CONTINUE) 5279 goto done; 5280 5281 if (!has_seg_override) 5282 ctxt->seg_override = VCPU_SREG_DS; 5283 5284 ctxt->memop.addr.mem.seg = ctxt->seg_override; 5285 5286 /* 5287 * Decode and fetch the source operand: register, memory 5288 * or immediate. 5289 */ 5290 rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask); 5291 if (rc != X86EMUL_CONTINUE) 5292 goto done; 5293 5294 /* 5295 * Decode and fetch the second source operand: register, memory 5296 * or immediate. 5297 */ 5298 rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask); 5299 if (rc != X86EMUL_CONTINUE) 5300 goto done; 5301 5302 /* Decode and fetch the destination operand: register or memory. */ 5303 rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask); 5304 5305 if (ctxt->rip_relative && likely(ctxt->memopp)) 5306 ctxt->memopp->addr.mem.ea = address_mask(ctxt, 5307 ctxt->memopp->addr.mem.ea + ctxt->_eip); 5308 5309 done: 5310 if (rc == X86EMUL_PROPAGATE_FAULT) 5311 ctxt->have_exception = true; 5312 return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK; 5313 } 5314 5315 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt) 5316 { 5317 return ctxt->d & PageTable; 5318 } 5319 5320 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt) 5321 { 5322 /* The second termination condition only applies for REPE 5323 * and REPNE. Test if the repeat string operation prefix is 5324 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the 5325 * corresponding termination condition according to: 5326 * - if REPE/REPZ and ZF = 0 then done 5327 * - if REPNE/REPNZ and ZF = 1 then done 5328 */ 5329 if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) || 5330 (ctxt->b == 0xae) || (ctxt->b == 0xaf)) 5331 && (((ctxt->rep_prefix == REPE_PREFIX) && 5332 ((ctxt->eflags & X86_EFLAGS_ZF) == 0)) 5333 || ((ctxt->rep_prefix == REPNE_PREFIX) && 5334 ((ctxt->eflags & X86_EFLAGS_ZF) == X86_EFLAGS_ZF)))) 5335 return true; 5336 5337 return false; 5338 } 5339 5340 static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt) 5341 { 5342 int rc; 5343 5344 kvm_fpu_get(); 5345 rc = asm_safe("fwait"); 5346 kvm_fpu_put(); 5347 5348 if (unlikely(rc != X86EMUL_CONTINUE)) 5349 return emulate_exception(ctxt, MF_VECTOR, 0, false); 5350 5351 return X86EMUL_CONTINUE; 5352 } 5353 5354 static void fetch_possible_mmx_operand(struct operand *op) 5355 { 5356 if (op->type == OP_MM) 5357 kvm_read_mmx_reg(op->addr.mm, &op->mm_val); 5358 } 5359 5360 static int fastop(struct x86_emulate_ctxt *ctxt, fastop_t fop) 5361 { 5362 ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF; 5363 5364 if (!(ctxt->d & ByteOp)) 5365 fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE; 5366 5367 asm("push %[flags]; popf; " CALL_NOSPEC " ; pushf; pop %[flags]\n" 5368 : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags), 5369 [thunk_target]"+S"(fop), ASM_CALL_CONSTRAINT 5370 : "c"(ctxt->src2.val)); 5371 5372 ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK); 5373 if (!fop) /* exception is returned in fop variable */ 5374 return emulate_de(ctxt); 5375 return X86EMUL_CONTINUE; 5376 } 5377 5378 void init_decode_cache(struct x86_emulate_ctxt *ctxt) 5379 { 5380 memset(&ctxt->rip_relative, 0, 5381 (void *)&ctxt->modrm - (void *)&ctxt->rip_relative); 5382 5383 ctxt->io_read.pos = 0; 5384 ctxt->io_read.end = 0; 5385 ctxt->mem_read.end = 0; 5386 } 5387 5388 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 5389 { 5390 const struct x86_emulate_ops *ops = ctxt->ops; 5391 int rc = X86EMUL_CONTINUE; 5392 int saved_dst_type = ctxt->dst.type; 5393 unsigned emul_flags; 5394 5395 ctxt->mem_read.pos = 0; 5396 5397 /* LOCK prefix is allowed only with some instructions */ 5398 if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) { 5399 rc = emulate_ud(ctxt); 5400 goto done; 5401 } 5402 5403 if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) { 5404 rc = emulate_ud(ctxt); 5405 goto done; 5406 } 5407 5408 emul_flags = ctxt->ops->get_hflags(ctxt); 5409 if (unlikely(ctxt->d & 5410 (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) { 5411 if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) || 5412 (ctxt->d & Undefined)) { 5413 rc = emulate_ud(ctxt); 5414 goto done; 5415 } 5416 5417 if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM))) 5418 || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) { 5419 rc = emulate_ud(ctxt); 5420 goto done; 5421 } 5422 5423 if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) { 5424 rc = emulate_nm(ctxt); 5425 goto done; 5426 } 5427 5428 if (ctxt->d & Mmx) { 5429 rc = flush_pending_x87_faults(ctxt); 5430 if (rc != X86EMUL_CONTINUE) 5431 goto done; 5432 /* 5433 * Now that we know the fpu is exception safe, we can fetch 5434 * operands from it. 5435 */ 5436 fetch_possible_mmx_operand(&ctxt->src); 5437 fetch_possible_mmx_operand(&ctxt->src2); 5438 if (!(ctxt->d & Mov)) 5439 fetch_possible_mmx_operand(&ctxt->dst); 5440 } 5441 5442 if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) { 5443 rc = emulator_check_intercept(ctxt, ctxt->intercept, 5444 X86_ICPT_PRE_EXCEPT); 5445 if (rc != X86EMUL_CONTINUE) 5446 goto done; 5447 } 5448 5449 /* Instruction can only be executed in protected mode */ 5450 if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) { 5451 rc = emulate_ud(ctxt); 5452 goto done; 5453 } 5454 5455 /* Privileged instruction can be executed only in CPL=0 */ 5456 if ((ctxt->d & Priv) && ops->cpl(ctxt)) { 5457 if (ctxt->d & PrivUD) 5458 rc = emulate_ud(ctxt); 5459 else 5460 rc = emulate_gp(ctxt, 0); 5461 goto done; 5462 } 5463 5464 /* Do instruction specific permission checks */ 5465 if (ctxt->d & CheckPerm) { 5466 rc = ctxt->check_perm(ctxt); 5467 if (rc != X86EMUL_CONTINUE) 5468 goto done; 5469 } 5470 5471 if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { 5472 rc = emulator_check_intercept(ctxt, ctxt->intercept, 5473 X86_ICPT_POST_EXCEPT); 5474 if (rc != X86EMUL_CONTINUE) 5475 goto done; 5476 } 5477 5478 if (ctxt->rep_prefix && (ctxt->d & String)) { 5479 /* All REP prefixes have the same first termination condition */ 5480 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) { 5481 string_registers_quirk(ctxt); 5482 ctxt->eip = ctxt->_eip; 5483 ctxt->eflags &= ~X86_EFLAGS_RF; 5484 goto done; 5485 } 5486 } 5487 } 5488 5489 if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) { 5490 rc = segmented_read(ctxt, ctxt->src.addr.mem, 5491 ctxt->src.valptr, ctxt->src.bytes); 5492 if (rc != X86EMUL_CONTINUE) 5493 goto done; 5494 ctxt->src.orig_val64 = ctxt->src.val64; 5495 } 5496 5497 if (ctxt->src2.type == OP_MEM) { 5498 rc = segmented_read(ctxt, ctxt->src2.addr.mem, 5499 &ctxt->src2.val, ctxt->src2.bytes); 5500 if (rc != X86EMUL_CONTINUE) 5501 goto done; 5502 } 5503 5504 if ((ctxt->d & DstMask) == ImplicitOps) 5505 goto special_insn; 5506 5507 5508 if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) { 5509 /* optimisation - avoid slow emulated read if Mov */ 5510 rc = segmented_read(ctxt, ctxt->dst.addr.mem, 5511 &ctxt->dst.val, ctxt->dst.bytes); 5512 if (rc != X86EMUL_CONTINUE) { 5513 if (!(ctxt->d & NoWrite) && 5514 rc == X86EMUL_PROPAGATE_FAULT && 5515 ctxt->exception.vector == PF_VECTOR) 5516 ctxt->exception.error_code |= PFERR_WRITE_MASK; 5517 goto done; 5518 } 5519 } 5520 /* Copy full 64-bit value for CMPXCHG8B. */ 5521 ctxt->dst.orig_val64 = ctxt->dst.val64; 5522 5523 special_insn: 5524 5525 if (unlikely(emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) { 5526 rc = emulator_check_intercept(ctxt, ctxt->intercept, 5527 X86_ICPT_POST_MEMACCESS); 5528 if (rc != X86EMUL_CONTINUE) 5529 goto done; 5530 } 5531 5532 if (ctxt->rep_prefix && (ctxt->d & String)) 5533 ctxt->eflags |= X86_EFLAGS_RF; 5534 else 5535 ctxt->eflags &= ~X86_EFLAGS_RF; 5536 5537 if (ctxt->execute) { 5538 if (ctxt->d & Fastop) 5539 rc = fastop(ctxt, ctxt->fop); 5540 else 5541 rc = ctxt->execute(ctxt); 5542 if (rc != X86EMUL_CONTINUE) 5543 goto done; 5544 goto writeback; 5545 } 5546 5547 if (ctxt->opcode_len == 2) 5548 goto twobyte_insn; 5549 else if (ctxt->opcode_len == 3) 5550 goto threebyte_insn; 5551 5552 switch (ctxt->b) { 5553 case 0x70 ... 0x7f: /* jcc (short) */ 5554 if (test_cc(ctxt->b, ctxt->eflags)) 5555 rc = jmp_rel(ctxt, ctxt->src.val); 5556 break; 5557 case 0x8d: /* lea r16/r32, m */ 5558 ctxt->dst.val = ctxt->src.addr.mem.ea; 5559 break; 5560 case 0x90 ... 0x97: /* nop / xchg reg, rax */ 5561 if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX)) 5562 ctxt->dst.type = OP_NONE; 5563 else 5564 rc = em_xchg(ctxt); 5565 break; 5566 case 0x98: /* cbw/cwde/cdqe */ 5567 switch (ctxt->op_bytes) { 5568 case 2: ctxt->dst.val = (s8)ctxt->dst.val; break; 5569 case 4: ctxt->dst.val = (s16)ctxt->dst.val; break; 5570 case 8: ctxt->dst.val = (s32)ctxt->dst.val; break; 5571 } 5572 break; 5573 case 0xcc: /* int3 */ 5574 rc = emulate_int(ctxt, 3); 5575 break; 5576 case 0xcd: /* int n */ 5577 rc = emulate_int(ctxt, ctxt->src.val); 5578 break; 5579 case 0xce: /* into */ 5580 if (ctxt->eflags & X86_EFLAGS_OF) 5581 rc = emulate_int(ctxt, 4); 5582 break; 5583 case 0xe9: /* jmp rel */ 5584 case 0xeb: /* jmp rel short */ 5585 rc = jmp_rel(ctxt, ctxt->src.val); 5586 ctxt->dst.type = OP_NONE; /* Disable writeback. */ 5587 break; 5588 case 0xf4: /* hlt */ 5589 ctxt->ops->halt(ctxt); 5590 break; 5591 case 0xf5: /* cmc */ 5592 /* complement carry flag from eflags reg */ 5593 ctxt->eflags ^= X86_EFLAGS_CF; 5594 break; 5595 case 0xf8: /* clc */ 5596 ctxt->eflags &= ~X86_EFLAGS_CF; 5597 break; 5598 case 0xf9: /* stc */ 5599 ctxt->eflags |= X86_EFLAGS_CF; 5600 break; 5601 case 0xfc: /* cld */ 5602 ctxt->eflags &= ~X86_EFLAGS_DF; 5603 break; 5604 case 0xfd: /* std */ 5605 ctxt->eflags |= X86_EFLAGS_DF; 5606 break; 5607 default: 5608 goto cannot_emulate; 5609 } 5610 5611 if (rc != X86EMUL_CONTINUE) 5612 goto done; 5613 5614 writeback: 5615 if (ctxt->d & SrcWrite) { 5616 BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR); 5617 rc = writeback(ctxt, &ctxt->src); 5618 if (rc != X86EMUL_CONTINUE) 5619 goto done; 5620 } 5621 if (!(ctxt->d & NoWrite)) { 5622 rc = writeback(ctxt, &ctxt->dst); 5623 if (rc != X86EMUL_CONTINUE) 5624 goto done; 5625 } 5626 5627 /* 5628 * restore dst type in case the decoding will be reused 5629 * (happens for string instruction ) 5630 */ 5631 ctxt->dst.type = saved_dst_type; 5632 5633 if ((ctxt->d & SrcMask) == SrcSI) 5634 string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src); 5635 5636 if ((ctxt->d & DstMask) == DstDI) 5637 string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst); 5638 5639 if (ctxt->rep_prefix && (ctxt->d & String)) { 5640 unsigned int count; 5641 struct read_cache *r = &ctxt->io_read; 5642 if ((ctxt->d & SrcMask) == SrcSI) 5643 count = ctxt->src.count; 5644 else 5645 count = ctxt->dst.count; 5646 register_address_increment(ctxt, VCPU_REGS_RCX, -count); 5647 5648 if (!string_insn_completed(ctxt)) { 5649 /* 5650 * Re-enter guest when pio read ahead buffer is empty 5651 * or, if it is not used, after each 1024 iteration. 5652 */ 5653 if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) && 5654 (r->end == 0 || r->end != r->pos)) { 5655 /* 5656 * Reset read cache. Usually happens before 5657 * decode, but since instruction is restarted 5658 * we have to do it here. 5659 */ 5660 ctxt->mem_read.end = 0; 5661 writeback_registers(ctxt); 5662 return EMULATION_RESTART; 5663 } 5664 goto done; /* skip rip writeback */ 5665 } 5666 ctxt->eflags &= ~X86_EFLAGS_RF; 5667 } 5668 5669 ctxt->eip = ctxt->_eip; 5670 if (ctxt->mode != X86EMUL_MODE_PROT64) 5671 ctxt->eip = (u32)ctxt->_eip; 5672 5673 done: 5674 if (rc == X86EMUL_PROPAGATE_FAULT) { 5675 WARN_ON(ctxt->exception.vector > 0x1f); 5676 ctxt->have_exception = true; 5677 } 5678 if (rc == X86EMUL_INTERCEPTED) 5679 return EMULATION_INTERCEPTED; 5680 5681 if (rc == X86EMUL_CONTINUE) 5682 writeback_registers(ctxt); 5683 5684 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 5685 5686 twobyte_insn: 5687 switch (ctxt->b) { 5688 case 0x09: /* wbinvd */ 5689 (ctxt->ops->wbinvd)(ctxt); 5690 break; 5691 case 0x08: /* invd */ 5692 case 0x0d: /* GrpP (prefetch) */ 5693 case 0x18: /* Grp16 (prefetch/nop) */ 5694 case 0x1f: /* nop */ 5695 break; 5696 case 0x20: /* mov cr, reg */ 5697 ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg); 5698 break; 5699 case 0x21: /* mov from dr to reg */ 5700 ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val); 5701 break; 5702 case 0x40 ... 0x4f: /* cmov */ 5703 if (test_cc(ctxt->b, ctxt->eflags)) 5704 ctxt->dst.val = ctxt->src.val; 5705 else if (ctxt->op_bytes != 4) 5706 ctxt->dst.type = OP_NONE; /* no writeback */ 5707 break; 5708 case 0x80 ... 0x8f: /* jnz rel, etc*/ 5709 if (test_cc(ctxt->b, ctxt->eflags)) 5710 rc = jmp_rel(ctxt, ctxt->src.val); 5711 break; 5712 case 0x90 ... 0x9f: /* setcc r/m8 */ 5713 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags); 5714 break; 5715 case 0xb6 ... 0xb7: /* movzx */ 5716 ctxt->dst.bytes = ctxt->op_bytes; 5717 ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val 5718 : (u16) ctxt->src.val; 5719 break; 5720 case 0xbe ... 0xbf: /* movsx */ 5721 ctxt->dst.bytes = ctxt->op_bytes; 5722 ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val : 5723 (s16) ctxt->src.val; 5724 break; 5725 default: 5726 goto cannot_emulate; 5727 } 5728 5729 threebyte_insn: 5730 5731 if (rc != X86EMUL_CONTINUE) 5732 goto done; 5733 5734 goto writeback; 5735 5736 cannot_emulate: 5737 return EMULATION_FAILED; 5738 } 5739 5740 void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt) 5741 { 5742 invalidate_registers(ctxt); 5743 } 5744 5745 void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt) 5746 { 5747 writeback_registers(ctxt); 5748 } 5749 5750 bool emulator_can_use_gpa(struct x86_emulate_ctxt *ctxt) 5751 { 5752 if (ctxt->rep_prefix && (ctxt->d & String)) 5753 return false; 5754 5755 if (ctxt->d & TwoMemOp) 5756 return false; 5757 5758 return true; 5759 } 5760