1 /****************************************************************************** 2 * emulate.c 3 * 4 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. 5 * 6 * Copyright (c) 2005 Keir Fraser 7 * 8 * Linux coding style, mod r/m decoder, segment base fixes, real-mode 9 * privileged instructions: 10 * 11 * Copyright (C) 2006 Qumranet 12 * Copyright 2010 Red Hat, Inc. and/or its affiliates. 13 * 14 * Avi Kivity <avi@qumranet.com> 15 * Yaniv Kamay <yaniv@qumranet.com> 16 * 17 * This work is licensed under the terms of the GNU GPL, version 2. See 18 * the COPYING file in the top-level directory. 19 * 20 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 21 */ 22 23 #include <linux/kvm_host.h> 24 #include "kvm_cache_regs.h" 25 #include <linux/module.h> 26 #include <asm/kvm_emulate.h> 27 28 #include "x86.h" 29 #include "tss.h" 30 31 /* 32 * Opcode effective-address decode tables. 33 * Note that we only emulate instructions that have at least one memory 34 * operand (excluding implicit stack references). We assume that stack 35 * references and instruction fetches will never occur in special memory 36 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need 37 * not be handled. 38 */ 39 40 /* Operand sizes: 8-bit operands or specified/overridden size. */ 41 #define ByteOp (1<<0) /* 8-bit operands. */ 42 /* Destination operand type. */ 43 #define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */ 44 #define DstReg (2<<1) /* Register operand. */ 45 #define DstMem (3<<1) /* Memory operand. */ 46 #define DstAcc (4<<1) /* Destination Accumulator */ 47 #define DstDI (5<<1) /* Destination is in ES:(E)DI */ 48 #define DstMem64 (6<<1) /* 64bit memory operand */ 49 #define DstImmUByte (7<<1) /* 8-bit unsigned immediate operand */ 50 #define DstDX (8<<1) /* Destination is in DX register */ 51 #define DstMask (0xf<<1) 52 /* Source operand type. */ 53 #define SrcNone (0<<5) /* No source operand. */ 54 #define SrcReg (1<<5) /* Register operand. */ 55 #define SrcMem (2<<5) /* Memory operand. */ 56 #define SrcMem16 (3<<5) /* Memory operand (16-bit). */ 57 #define SrcMem32 (4<<5) /* Memory operand (32-bit). */ 58 #define SrcImm (5<<5) /* Immediate operand. */ 59 #define SrcImmByte (6<<5) /* 8-bit sign-extended immediate operand. */ 60 #define SrcOne (7<<5) /* Implied '1' */ 61 #define SrcImmUByte (8<<5) /* 8-bit unsigned immediate operand. */ 62 #define SrcImmU (9<<5) /* Immediate operand, unsigned */ 63 #define SrcSI (0xa<<5) /* Source is in the DS:RSI */ 64 #define SrcImmFAddr (0xb<<5) /* Source is immediate far address */ 65 #define SrcMemFAddr (0xc<<5) /* Source is far address in memory */ 66 #define SrcAcc (0xd<<5) /* Source Accumulator */ 67 #define SrcImmU16 (0xe<<5) /* Immediate operand, unsigned, 16 bits */ 68 #define SrcDX (0xf<<5) /* Source is in DX register */ 69 #define SrcMask (0xf<<5) 70 /* Generic ModRM decode. */ 71 #define ModRM (1<<9) 72 /* Destination is only written; never read. */ 73 #define Mov (1<<10) 74 #define BitOp (1<<11) 75 #define MemAbs (1<<12) /* Memory operand is absolute displacement */ 76 #define String (1<<13) /* String instruction (rep capable) */ 77 #define Stack (1<<14) /* Stack instruction (push/pop) */ 78 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */ 79 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */ 80 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */ 81 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */ 82 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */ 83 #define Sse (1<<18) /* SSE Vector instruction */ 84 /* Misc flags */ 85 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */ 86 #define VendorSpecific (1<<22) /* Vendor specific instruction */ 87 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */ 88 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */ 89 #define Undefined (1<<25) /* No Such Instruction */ 90 #define Lock (1<<26) /* lock prefix is allowed for the instruction */ 91 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */ 92 #define No64 (1<<28) 93 /* Source 2 operand type */ 94 #define Src2None (0<<29) 95 #define Src2CL (1<<29) 96 #define Src2ImmByte (2<<29) 97 #define Src2One (3<<29) 98 #define Src2Imm (4<<29) 99 #define Src2Mask (7<<29) 100 101 #define X2(x...) x, x 102 #define X3(x...) X2(x), x 103 #define X4(x...) X2(x), X2(x) 104 #define X5(x...) X4(x), x 105 #define X6(x...) X4(x), X2(x) 106 #define X7(x...) X4(x), X3(x) 107 #define X8(x...) X4(x), X4(x) 108 #define X16(x...) X8(x), X8(x) 109 110 struct opcode { 111 u32 flags; 112 u8 intercept; 113 union { 114 int (*execute)(struct x86_emulate_ctxt *ctxt); 115 struct opcode *group; 116 struct group_dual *gdual; 117 struct gprefix *gprefix; 118 } u; 119 int (*check_perm)(struct x86_emulate_ctxt *ctxt); 120 }; 121 122 struct group_dual { 123 struct opcode mod012[8]; 124 struct opcode mod3[8]; 125 }; 126 127 struct gprefix { 128 struct opcode pfx_no; 129 struct opcode pfx_66; 130 struct opcode pfx_f2; 131 struct opcode pfx_f3; 132 }; 133 134 /* EFLAGS bit definitions. */ 135 #define EFLG_ID (1<<21) 136 #define EFLG_VIP (1<<20) 137 #define EFLG_VIF (1<<19) 138 #define EFLG_AC (1<<18) 139 #define EFLG_VM (1<<17) 140 #define EFLG_RF (1<<16) 141 #define EFLG_IOPL (3<<12) 142 #define EFLG_NT (1<<14) 143 #define EFLG_OF (1<<11) 144 #define EFLG_DF (1<<10) 145 #define EFLG_IF (1<<9) 146 #define EFLG_TF (1<<8) 147 #define EFLG_SF (1<<7) 148 #define EFLG_ZF (1<<6) 149 #define EFLG_AF (1<<4) 150 #define EFLG_PF (1<<2) 151 #define EFLG_CF (1<<0) 152 153 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a 154 #define EFLG_RESERVED_ONE_MASK 2 155 156 /* 157 * Instruction emulation: 158 * Most instructions are emulated directly via a fragment of inline assembly 159 * code. This allows us to save/restore EFLAGS and thus very easily pick up 160 * any modified flags. 161 */ 162 163 #if defined(CONFIG_X86_64) 164 #define _LO32 "k" /* force 32-bit operand */ 165 #define _STK "%%rsp" /* stack pointer */ 166 #elif defined(__i386__) 167 #define _LO32 "" /* force 32-bit operand */ 168 #define _STK "%%esp" /* stack pointer */ 169 #endif 170 171 /* 172 * These EFLAGS bits are restored from saved value during emulation, and 173 * any changes are written back to the saved value after emulation. 174 */ 175 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF) 176 177 /* Before executing instruction: restore necessary bits in EFLAGS. */ 178 #define _PRE_EFLAGS(_sav, _msk, _tmp) \ 179 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \ 180 "movl %"_sav",%"_LO32 _tmp"; " \ 181 "push %"_tmp"; " \ 182 "push %"_tmp"; " \ 183 "movl %"_msk",%"_LO32 _tmp"; " \ 184 "andl %"_LO32 _tmp",("_STK"); " \ 185 "pushf; " \ 186 "notl %"_LO32 _tmp"; " \ 187 "andl %"_LO32 _tmp",("_STK"); " \ 188 "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \ 189 "pop %"_tmp"; " \ 190 "orl %"_LO32 _tmp",("_STK"); " \ 191 "popf; " \ 192 "pop %"_sav"; " 193 194 /* After executing instruction: write-back necessary bits in EFLAGS. */ 195 #define _POST_EFLAGS(_sav, _msk, _tmp) \ 196 /* _sav |= EFLAGS & _msk; */ \ 197 "pushf; " \ 198 "pop %"_tmp"; " \ 199 "andl %"_msk",%"_LO32 _tmp"; " \ 200 "orl %"_LO32 _tmp",%"_sav"; " 201 202 #ifdef CONFIG_X86_64 203 #define ON64(x) x 204 #else 205 #define ON64(x) 206 #endif 207 208 #define ____emulate_2op(_op, _src, _dst, _eflags, _x, _y, _suffix, _dsttype) \ 209 do { \ 210 __asm__ __volatile__ ( \ 211 _PRE_EFLAGS("0", "4", "2") \ 212 _op _suffix " %"_x"3,%1; " \ 213 _POST_EFLAGS("0", "4", "2") \ 214 : "=m" (_eflags), "+q" (*(_dsttype*)&(_dst).val),\ 215 "=&r" (_tmp) \ 216 : _y ((_src).val), "i" (EFLAGS_MASK)); \ 217 } while (0) 218 219 220 /* Raw emulation: instruction has two explicit operands. */ 221 #define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \ 222 do { \ 223 unsigned long _tmp; \ 224 \ 225 switch ((_dst).bytes) { \ 226 case 2: \ 227 ____emulate_2op(_op,_src,_dst,_eflags,_wx,_wy,"w",u16);\ 228 break; \ 229 case 4: \ 230 ____emulate_2op(_op,_src,_dst,_eflags,_lx,_ly,"l",u32);\ 231 break; \ 232 case 8: \ 233 ON64(____emulate_2op(_op,_src,_dst,_eflags,_qx,_qy,"q",u64)); \ 234 break; \ 235 } \ 236 } while (0) 237 238 #define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \ 239 do { \ 240 unsigned long _tmp; \ 241 switch ((_dst).bytes) { \ 242 case 1: \ 243 ____emulate_2op(_op,_src,_dst,_eflags,_bx,_by,"b",u8); \ 244 break; \ 245 default: \ 246 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \ 247 _wx, _wy, _lx, _ly, _qx, _qy); \ 248 break; \ 249 } \ 250 } while (0) 251 252 /* Source operand is byte-sized and may be restricted to just %cl. */ 253 #define emulate_2op_SrcB(_op, _src, _dst, _eflags) \ 254 __emulate_2op(_op, _src, _dst, _eflags, \ 255 "b", "c", "b", "c", "b", "c", "b", "c") 256 257 /* Source operand is byte, word, long or quad sized. */ 258 #define emulate_2op_SrcV(_op, _src, _dst, _eflags) \ 259 __emulate_2op(_op, _src, _dst, _eflags, \ 260 "b", "q", "w", "r", _LO32, "r", "", "r") 261 262 /* Source operand is word, long or quad sized. */ 263 #define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \ 264 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \ 265 "w", "r", _LO32, "r", "", "r") 266 267 /* Instruction has three operands and one operand is stored in ECX register */ 268 #define __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, _suffix, _type) \ 269 do { \ 270 unsigned long _tmp; \ 271 _type _clv = (_cl).val; \ 272 _type _srcv = (_src).val; \ 273 _type _dstv = (_dst).val; \ 274 \ 275 __asm__ __volatile__ ( \ 276 _PRE_EFLAGS("0", "5", "2") \ 277 _op _suffix " %4,%1 \n" \ 278 _POST_EFLAGS("0", "5", "2") \ 279 : "=m" (_eflags), "+r" (_dstv), "=&r" (_tmp) \ 280 : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \ 281 ); \ 282 \ 283 (_cl).val = (unsigned long) _clv; \ 284 (_src).val = (unsigned long) _srcv; \ 285 (_dst).val = (unsigned long) _dstv; \ 286 } while (0) 287 288 #define emulate_2op_cl(_op, _cl, _src, _dst, _eflags) \ 289 do { \ 290 switch ((_dst).bytes) { \ 291 case 2: \ 292 __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ 293 "w", unsigned short); \ 294 break; \ 295 case 4: \ 296 __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ 297 "l", unsigned int); \ 298 break; \ 299 case 8: \ 300 ON64(__emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \ 301 "q", unsigned long)); \ 302 break; \ 303 } \ 304 } while (0) 305 306 #define __emulate_1op(_op, _dst, _eflags, _suffix) \ 307 do { \ 308 unsigned long _tmp; \ 309 \ 310 __asm__ __volatile__ ( \ 311 _PRE_EFLAGS("0", "3", "2") \ 312 _op _suffix " %1; " \ 313 _POST_EFLAGS("0", "3", "2") \ 314 : "=m" (_eflags), "+m" ((_dst).val), \ 315 "=&r" (_tmp) \ 316 : "i" (EFLAGS_MASK)); \ 317 } while (0) 318 319 /* Instruction has only one explicit operand (no source operand). */ 320 #define emulate_1op(_op, _dst, _eflags) \ 321 do { \ 322 switch ((_dst).bytes) { \ 323 case 1: __emulate_1op(_op, _dst, _eflags, "b"); break; \ 324 case 2: __emulate_1op(_op, _dst, _eflags, "w"); break; \ 325 case 4: __emulate_1op(_op, _dst, _eflags, "l"); break; \ 326 case 8: ON64(__emulate_1op(_op, _dst, _eflags, "q")); break; \ 327 } \ 328 } while (0) 329 330 #define __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags, _suffix) \ 331 do { \ 332 unsigned long _tmp; \ 333 \ 334 __asm__ __volatile__ ( \ 335 _PRE_EFLAGS("0", "4", "1") \ 336 _op _suffix " %5; " \ 337 _POST_EFLAGS("0", "4", "1") \ 338 : "=m" (_eflags), "=&r" (_tmp), \ 339 "+a" (_rax), "+d" (_rdx) \ 340 : "i" (EFLAGS_MASK), "m" ((_src).val), \ 341 "a" (_rax), "d" (_rdx)); \ 342 } while (0) 343 344 #define __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, _eflags, _suffix, _ex) \ 345 do { \ 346 unsigned long _tmp; \ 347 \ 348 __asm__ __volatile__ ( \ 349 _PRE_EFLAGS("0", "5", "1") \ 350 "1: \n\t" \ 351 _op _suffix " %6; " \ 352 "2: \n\t" \ 353 _POST_EFLAGS("0", "5", "1") \ 354 ".pushsection .fixup,\"ax\" \n\t" \ 355 "3: movb $1, %4 \n\t" \ 356 "jmp 2b \n\t" \ 357 ".popsection \n\t" \ 358 _ASM_EXTABLE(1b, 3b) \ 359 : "=m" (_eflags), "=&r" (_tmp), \ 360 "+a" (_rax), "+d" (_rdx), "+qm"(_ex) \ 361 : "i" (EFLAGS_MASK), "m" ((_src).val), \ 362 "a" (_rax), "d" (_rdx)); \ 363 } while (0) 364 365 /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */ 366 #define emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags) \ 367 do { \ 368 switch((_src).bytes) { \ 369 case 1: \ 370 __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, \ 371 _eflags, "b"); \ 372 break; \ 373 case 2: \ 374 __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, \ 375 _eflags, "w"); \ 376 break; \ 377 case 4: \ 378 __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, \ 379 _eflags, "l"); \ 380 break; \ 381 case 8: \ 382 ON64(__emulate_1op_rax_rdx(_op, _src, _rax, _rdx, \ 383 _eflags, "q")); \ 384 break; \ 385 } \ 386 } while (0) 387 388 #define emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, _eflags, _ex) \ 389 do { \ 390 switch((_src).bytes) { \ 391 case 1: \ 392 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \ 393 _eflags, "b", _ex); \ 394 break; \ 395 case 2: \ 396 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \ 397 _eflags, "w", _ex); \ 398 break; \ 399 case 4: \ 400 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \ 401 _eflags, "l", _ex); \ 402 break; \ 403 case 8: ON64( \ 404 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \ 405 _eflags, "q", _ex)); \ 406 break; \ 407 } \ 408 } while (0) 409 410 /* Fetch next part of the instruction being emulated. */ 411 #define insn_fetch(_type, _size, _eip) \ 412 ({ unsigned long _x; \ 413 rc = do_insn_fetch(ctxt, ops, (_eip), &_x, (_size)); \ 414 if (rc != X86EMUL_CONTINUE) \ 415 goto done; \ 416 (_eip) += (_size); \ 417 (_type)_x; \ 418 }) 419 420 #define insn_fetch_arr(_arr, _size, _eip) \ 421 ({ rc = do_insn_fetch(ctxt, ops, (_eip), _arr, (_size)); \ 422 if (rc != X86EMUL_CONTINUE) \ 423 goto done; \ 424 (_eip) += (_size); \ 425 }) 426 427 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt, 428 enum x86_intercept intercept, 429 enum x86_intercept_stage stage) 430 { 431 struct x86_instruction_info info = { 432 .intercept = intercept, 433 .rep_prefix = ctxt->decode.rep_prefix, 434 .modrm_mod = ctxt->decode.modrm_mod, 435 .modrm_reg = ctxt->decode.modrm_reg, 436 .modrm_rm = ctxt->decode.modrm_rm, 437 .src_val = ctxt->decode.src.val64, 438 .src_bytes = ctxt->decode.src.bytes, 439 .dst_bytes = ctxt->decode.dst.bytes, 440 .ad_bytes = ctxt->decode.ad_bytes, 441 .next_rip = ctxt->eip, 442 }; 443 444 return ctxt->ops->intercept(ctxt, &info, stage); 445 } 446 447 static inline unsigned long ad_mask(struct decode_cache *c) 448 { 449 return (1UL << (c->ad_bytes << 3)) - 1; 450 } 451 452 /* Access/update address held in a register, based on addressing mode. */ 453 static inline unsigned long 454 address_mask(struct decode_cache *c, unsigned long reg) 455 { 456 if (c->ad_bytes == sizeof(unsigned long)) 457 return reg; 458 else 459 return reg & ad_mask(c); 460 } 461 462 static inline unsigned long 463 register_address(struct decode_cache *c, unsigned long reg) 464 { 465 return address_mask(c, reg); 466 } 467 468 static inline void 469 register_address_increment(struct decode_cache *c, unsigned long *reg, int inc) 470 { 471 if (c->ad_bytes == sizeof(unsigned long)) 472 *reg += inc; 473 else 474 *reg = (*reg & ~ad_mask(c)) | ((*reg + inc) & ad_mask(c)); 475 } 476 477 static inline void jmp_rel(struct decode_cache *c, int rel) 478 { 479 register_address_increment(c, &c->eip, rel); 480 } 481 482 static u32 desc_limit_scaled(struct desc_struct *desc) 483 { 484 u32 limit = get_desc_limit(desc); 485 486 return desc->g ? (limit << 12) | 0xfff : limit; 487 } 488 489 static void set_seg_override(struct decode_cache *c, int seg) 490 { 491 c->has_seg_override = true; 492 c->seg_override = seg; 493 } 494 495 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, 496 struct x86_emulate_ops *ops, int seg) 497 { 498 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS) 499 return 0; 500 501 return ops->get_cached_segment_base(ctxt, seg); 502 } 503 504 static unsigned seg_override(struct x86_emulate_ctxt *ctxt, 505 struct decode_cache *c) 506 { 507 if (!c->has_seg_override) 508 return 0; 509 510 return c->seg_override; 511 } 512 513 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec, 514 u32 error, bool valid) 515 { 516 ctxt->exception.vector = vec; 517 ctxt->exception.error_code = error; 518 ctxt->exception.error_code_valid = valid; 519 return X86EMUL_PROPAGATE_FAULT; 520 } 521 522 static int emulate_db(struct x86_emulate_ctxt *ctxt) 523 { 524 return emulate_exception(ctxt, DB_VECTOR, 0, false); 525 } 526 527 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err) 528 { 529 return emulate_exception(ctxt, GP_VECTOR, err, true); 530 } 531 532 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err) 533 { 534 return emulate_exception(ctxt, SS_VECTOR, err, true); 535 } 536 537 static int emulate_ud(struct x86_emulate_ctxt *ctxt) 538 { 539 return emulate_exception(ctxt, UD_VECTOR, 0, false); 540 } 541 542 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err) 543 { 544 return emulate_exception(ctxt, TS_VECTOR, err, true); 545 } 546 547 static int emulate_de(struct x86_emulate_ctxt *ctxt) 548 { 549 return emulate_exception(ctxt, DE_VECTOR, 0, false); 550 } 551 552 static int emulate_nm(struct x86_emulate_ctxt *ctxt) 553 { 554 return emulate_exception(ctxt, NM_VECTOR, 0, false); 555 } 556 557 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg) 558 { 559 u16 selector; 560 struct desc_struct desc; 561 562 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg); 563 return selector; 564 } 565 566 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector, 567 unsigned seg) 568 { 569 u16 dummy; 570 u32 base3; 571 struct desc_struct desc; 572 573 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg); 574 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg); 575 } 576 577 static int __linearize(struct x86_emulate_ctxt *ctxt, 578 struct segmented_address addr, 579 unsigned size, bool write, bool fetch, 580 ulong *linear) 581 { 582 struct decode_cache *c = &ctxt->decode; 583 struct desc_struct desc; 584 bool usable; 585 ulong la; 586 u32 lim; 587 u16 sel; 588 unsigned cpl, rpl; 589 590 la = seg_base(ctxt, ctxt->ops, addr.seg) + addr.ea; 591 switch (ctxt->mode) { 592 case X86EMUL_MODE_REAL: 593 break; 594 case X86EMUL_MODE_PROT64: 595 if (((signed long)la << 16) >> 16 != la) 596 return emulate_gp(ctxt, 0); 597 break; 598 default: 599 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL, 600 addr.seg); 601 if (!usable) 602 goto bad; 603 /* code segment or read-only data segment */ 604 if (((desc.type & 8) || !(desc.type & 2)) && write) 605 goto bad; 606 /* unreadable code segment */ 607 if (!fetch && (desc.type & 8) && !(desc.type & 2)) 608 goto bad; 609 lim = desc_limit_scaled(&desc); 610 if ((desc.type & 8) || !(desc.type & 4)) { 611 /* expand-up segment */ 612 if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim) 613 goto bad; 614 } else { 615 /* exapand-down segment */ 616 if (addr.ea <= lim || (u32)(addr.ea + size - 1) <= lim) 617 goto bad; 618 lim = desc.d ? 0xffffffff : 0xffff; 619 if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim) 620 goto bad; 621 } 622 cpl = ctxt->ops->cpl(ctxt); 623 rpl = sel & 3; 624 cpl = max(cpl, rpl); 625 if (!(desc.type & 8)) { 626 /* data segment */ 627 if (cpl > desc.dpl) 628 goto bad; 629 } else if ((desc.type & 8) && !(desc.type & 4)) { 630 /* nonconforming code segment */ 631 if (cpl != desc.dpl) 632 goto bad; 633 } else if ((desc.type & 8) && (desc.type & 4)) { 634 /* conforming code segment */ 635 if (cpl < desc.dpl) 636 goto bad; 637 } 638 break; 639 } 640 if (fetch ? ctxt->mode != X86EMUL_MODE_PROT64 : c->ad_bytes != 8) 641 la &= (u32)-1; 642 *linear = la; 643 return X86EMUL_CONTINUE; 644 bad: 645 if (addr.seg == VCPU_SREG_SS) 646 return emulate_ss(ctxt, addr.seg); 647 else 648 return emulate_gp(ctxt, addr.seg); 649 } 650 651 static int linearize(struct x86_emulate_ctxt *ctxt, 652 struct segmented_address addr, 653 unsigned size, bool write, 654 ulong *linear) 655 { 656 return __linearize(ctxt, addr, size, write, false, linear); 657 } 658 659 660 static int segmented_read_std(struct x86_emulate_ctxt *ctxt, 661 struct segmented_address addr, 662 void *data, 663 unsigned size) 664 { 665 int rc; 666 ulong linear; 667 668 rc = linearize(ctxt, addr, size, false, &linear); 669 if (rc != X86EMUL_CONTINUE) 670 return rc; 671 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception); 672 } 673 674 static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt, 675 struct x86_emulate_ops *ops, 676 unsigned long eip, u8 *dest) 677 { 678 struct fetch_cache *fc = &ctxt->decode.fetch; 679 int rc; 680 int size, cur_size; 681 682 if (eip == fc->end) { 683 unsigned long linear; 684 struct segmented_address addr = { .seg=VCPU_SREG_CS, .ea=eip}; 685 cur_size = fc->end - fc->start; 686 size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(eip)); 687 rc = __linearize(ctxt, addr, size, false, true, &linear); 688 if (rc != X86EMUL_CONTINUE) 689 return rc; 690 rc = ops->fetch(ctxt, linear, fc->data + cur_size, 691 size, &ctxt->exception); 692 if (rc != X86EMUL_CONTINUE) 693 return rc; 694 fc->end += size; 695 } 696 *dest = fc->data[eip - fc->start]; 697 return X86EMUL_CONTINUE; 698 } 699 700 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt, 701 struct x86_emulate_ops *ops, 702 unsigned long eip, void *dest, unsigned size) 703 { 704 int rc; 705 706 /* x86 instructions are limited to 15 bytes. */ 707 if (eip + size - ctxt->eip > 15) 708 return X86EMUL_UNHANDLEABLE; 709 while (size--) { 710 rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++); 711 if (rc != X86EMUL_CONTINUE) 712 return rc; 713 } 714 return X86EMUL_CONTINUE; 715 } 716 717 /* 718 * Given the 'reg' portion of a ModRM byte, and a register block, return a 719 * pointer into the block that addresses the relevant register. 720 * @highbyte_regs specifies whether to decode AH,CH,DH,BH. 721 */ 722 static void *decode_register(u8 modrm_reg, unsigned long *regs, 723 int highbyte_regs) 724 { 725 void *p; 726 727 p = ®s[modrm_reg]; 728 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8) 729 p = (unsigned char *)®s[modrm_reg & 3] + 1; 730 return p; 731 } 732 733 static int read_descriptor(struct x86_emulate_ctxt *ctxt, 734 struct segmented_address addr, 735 u16 *size, unsigned long *address, int op_bytes) 736 { 737 int rc; 738 739 if (op_bytes == 2) 740 op_bytes = 3; 741 *address = 0; 742 rc = segmented_read_std(ctxt, addr, size, 2); 743 if (rc != X86EMUL_CONTINUE) 744 return rc; 745 addr.ea += 2; 746 rc = segmented_read_std(ctxt, addr, address, op_bytes); 747 return rc; 748 } 749 750 static int test_cc(unsigned int condition, unsigned int flags) 751 { 752 int rc = 0; 753 754 switch ((condition & 15) >> 1) { 755 case 0: /* o */ 756 rc |= (flags & EFLG_OF); 757 break; 758 case 1: /* b/c/nae */ 759 rc |= (flags & EFLG_CF); 760 break; 761 case 2: /* z/e */ 762 rc |= (flags & EFLG_ZF); 763 break; 764 case 3: /* be/na */ 765 rc |= (flags & (EFLG_CF|EFLG_ZF)); 766 break; 767 case 4: /* s */ 768 rc |= (flags & EFLG_SF); 769 break; 770 case 5: /* p/pe */ 771 rc |= (flags & EFLG_PF); 772 break; 773 case 7: /* le/ng */ 774 rc |= (flags & EFLG_ZF); 775 /* fall through */ 776 case 6: /* l/nge */ 777 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF)); 778 break; 779 } 780 781 /* Odd condition identifiers (lsb == 1) have inverted sense. */ 782 return (!!rc ^ (condition & 1)); 783 } 784 785 static void fetch_register_operand(struct operand *op) 786 { 787 switch (op->bytes) { 788 case 1: 789 op->val = *(u8 *)op->addr.reg; 790 break; 791 case 2: 792 op->val = *(u16 *)op->addr.reg; 793 break; 794 case 4: 795 op->val = *(u32 *)op->addr.reg; 796 break; 797 case 8: 798 op->val = *(u64 *)op->addr.reg; 799 break; 800 } 801 } 802 803 static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg) 804 { 805 ctxt->ops->get_fpu(ctxt); 806 switch (reg) { 807 case 0: asm("movdqu %%xmm0, %0" : "=m"(*data)); break; 808 case 1: asm("movdqu %%xmm1, %0" : "=m"(*data)); break; 809 case 2: asm("movdqu %%xmm2, %0" : "=m"(*data)); break; 810 case 3: asm("movdqu %%xmm3, %0" : "=m"(*data)); break; 811 case 4: asm("movdqu %%xmm4, %0" : "=m"(*data)); break; 812 case 5: asm("movdqu %%xmm5, %0" : "=m"(*data)); break; 813 case 6: asm("movdqu %%xmm6, %0" : "=m"(*data)); break; 814 case 7: asm("movdqu %%xmm7, %0" : "=m"(*data)); break; 815 #ifdef CONFIG_X86_64 816 case 8: asm("movdqu %%xmm8, %0" : "=m"(*data)); break; 817 case 9: asm("movdqu %%xmm9, %0" : "=m"(*data)); break; 818 case 10: asm("movdqu %%xmm10, %0" : "=m"(*data)); break; 819 case 11: asm("movdqu %%xmm11, %0" : "=m"(*data)); break; 820 case 12: asm("movdqu %%xmm12, %0" : "=m"(*data)); break; 821 case 13: asm("movdqu %%xmm13, %0" : "=m"(*data)); break; 822 case 14: asm("movdqu %%xmm14, %0" : "=m"(*data)); break; 823 case 15: asm("movdqu %%xmm15, %0" : "=m"(*data)); break; 824 #endif 825 default: BUG(); 826 } 827 ctxt->ops->put_fpu(ctxt); 828 } 829 830 static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, 831 int reg) 832 { 833 ctxt->ops->get_fpu(ctxt); 834 switch (reg) { 835 case 0: asm("movdqu %0, %%xmm0" : : "m"(*data)); break; 836 case 1: asm("movdqu %0, %%xmm1" : : "m"(*data)); break; 837 case 2: asm("movdqu %0, %%xmm2" : : "m"(*data)); break; 838 case 3: asm("movdqu %0, %%xmm3" : : "m"(*data)); break; 839 case 4: asm("movdqu %0, %%xmm4" : : "m"(*data)); break; 840 case 5: asm("movdqu %0, %%xmm5" : : "m"(*data)); break; 841 case 6: asm("movdqu %0, %%xmm6" : : "m"(*data)); break; 842 case 7: asm("movdqu %0, %%xmm7" : : "m"(*data)); break; 843 #ifdef CONFIG_X86_64 844 case 8: asm("movdqu %0, %%xmm8" : : "m"(*data)); break; 845 case 9: asm("movdqu %0, %%xmm9" : : "m"(*data)); break; 846 case 10: asm("movdqu %0, %%xmm10" : : "m"(*data)); break; 847 case 11: asm("movdqu %0, %%xmm11" : : "m"(*data)); break; 848 case 12: asm("movdqu %0, %%xmm12" : : "m"(*data)); break; 849 case 13: asm("movdqu %0, %%xmm13" : : "m"(*data)); break; 850 case 14: asm("movdqu %0, %%xmm14" : : "m"(*data)); break; 851 case 15: asm("movdqu %0, %%xmm15" : : "m"(*data)); break; 852 #endif 853 default: BUG(); 854 } 855 ctxt->ops->put_fpu(ctxt); 856 } 857 858 static void decode_register_operand(struct x86_emulate_ctxt *ctxt, 859 struct operand *op, 860 struct decode_cache *c, 861 int inhibit_bytereg) 862 { 863 unsigned reg = c->modrm_reg; 864 int highbyte_regs = c->rex_prefix == 0; 865 866 if (!(c->d & ModRM)) 867 reg = (c->b & 7) | ((c->rex_prefix & 1) << 3); 868 869 if (c->d & Sse) { 870 op->type = OP_XMM; 871 op->bytes = 16; 872 op->addr.xmm = reg; 873 read_sse_reg(ctxt, &op->vec_val, reg); 874 return; 875 } 876 877 op->type = OP_REG; 878 if ((c->d & ByteOp) && !inhibit_bytereg) { 879 op->addr.reg = decode_register(reg, c->regs, highbyte_regs); 880 op->bytes = 1; 881 } else { 882 op->addr.reg = decode_register(reg, c->regs, 0); 883 op->bytes = c->op_bytes; 884 } 885 fetch_register_operand(op); 886 op->orig_val = op->val; 887 } 888 889 static int decode_modrm(struct x86_emulate_ctxt *ctxt, 890 struct x86_emulate_ops *ops, 891 struct operand *op) 892 { 893 struct decode_cache *c = &ctxt->decode; 894 u8 sib; 895 int index_reg = 0, base_reg = 0, scale; 896 int rc = X86EMUL_CONTINUE; 897 ulong modrm_ea = 0; 898 899 if (c->rex_prefix) { 900 c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */ 901 index_reg = (c->rex_prefix & 2) << 2; /* REX.X */ 902 c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */ 903 } 904 905 c->modrm = insn_fetch(u8, 1, c->eip); 906 c->modrm_mod |= (c->modrm & 0xc0) >> 6; 907 c->modrm_reg |= (c->modrm & 0x38) >> 3; 908 c->modrm_rm |= (c->modrm & 0x07); 909 c->modrm_seg = VCPU_SREG_DS; 910 911 if (c->modrm_mod == 3) { 912 op->type = OP_REG; 913 op->bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 914 op->addr.reg = decode_register(c->modrm_rm, 915 c->regs, c->d & ByteOp); 916 if (c->d & Sse) { 917 op->type = OP_XMM; 918 op->bytes = 16; 919 op->addr.xmm = c->modrm_rm; 920 read_sse_reg(ctxt, &op->vec_val, c->modrm_rm); 921 return rc; 922 } 923 fetch_register_operand(op); 924 return rc; 925 } 926 927 op->type = OP_MEM; 928 929 if (c->ad_bytes == 2) { 930 unsigned bx = c->regs[VCPU_REGS_RBX]; 931 unsigned bp = c->regs[VCPU_REGS_RBP]; 932 unsigned si = c->regs[VCPU_REGS_RSI]; 933 unsigned di = c->regs[VCPU_REGS_RDI]; 934 935 /* 16-bit ModR/M decode. */ 936 switch (c->modrm_mod) { 937 case 0: 938 if (c->modrm_rm == 6) 939 modrm_ea += insn_fetch(u16, 2, c->eip); 940 break; 941 case 1: 942 modrm_ea += insn_fetch(s8, 1, c->eip); 943 break; 944 case 2: 945 modrm_ea += insn_fetch(u16, 2, c->eip); 946 break; 947 } 948 switch (c->modrm_rm) { 949 case 0: 950 modrm_ea += bx + si; 951 break; 952 case 1: 953 modrm_ea += bx + di; 954 break; 955 case 2: 956 modrm_ea += bp + si; 957 break; 958 case 3: 959 modrm_ea += bp + di; 960 break; 961 case 4: 962 modrm_ea += si; 963 break; 964 case 5: 965 modrm_ea += di; 966 break; 967 case 6: 968 if (c->modrm_mod != 0) 969 modrm_ea += bp; 970 break; 971 case 7: 972 modrm_ea += bx; 973 break; 974 } 975 if (c->modrm_rm == 2 || c->modrm_rm == 3 || 976 (c->modrm_rm == 6 && c->modrm_mod != 0)) 977 c->modrm_seg = VCPU_SREG_SS; 978 modrm_ea = (u16)modrm_ea; 979 } else { 980 /* 32/64-bit ModR/M decode. */ 981 if ((c->modrm_rm & 7) == 4) { 982 sib = insn_fetch(u8, 1, c->eip); 983 index_reg |= (sib >> 3) & 7; 984 base_reg |= sib & 7; 985 scale = sib >> 6; 986 987 if ((base_reg & 7) == 5 && c->modrm_mod == 0) 988 modrm_ea += insn_fetch(s32, 4, c->eip); 989 else 990 modrm_ea += c->regs[base_reg]; 991 if (index_reg != 4) 992 modrm_ea += c->regs[index_reg] << scale; 993 } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) { 994 if (ctxt->mode == X86EMUL_MODE_PROT64) 995 c->rip_relative = 1; 996 } else 997 modrm_ea += c->regs[c->modrm_rm]; 998 switch (c->modrm_mod) { 999 case 0: 1000 if (c->modrm_rm == 5) 1001 modrm_ea += insn_fetch(s32, 4, c->eip); 1002 break; 1003 case 1: 1004 modrm_ea += insn_fetch(s8, 1, c->eip); 1005 break; 1006 case 2: 1007 modrm_ea += insn_fetch(s32, 4, c->eip); 1008 break; 1009 } 1010 } 1011 op->addr.mem.ea = modrm_ea; 1012 done: 1013 return rc; 1014 } 1015 1016 static int decode_abs(struct x86_emulate_ctxt *ctxt, 1017 struct x86_emulate_ops *ops, 1018 struct operand *op) 1019 { 1020 struct decode_cache *c = &ctxt->decode; 1021 int rc = X86EMUL_CONTINUE; 1022 1023 op->type = OP_MEM; 1024 switch (c->ad_bytes) { 1025 case 2: 1026 op->addr.mem.ea = insn_fetch(u16, 2, c->eip); 1027 break; 1028 case 4: 1029 op->addr.mem.ea = insn_fetch(u32, 4, c->eip); 1030 break; 1031 case 8: 1032 op->addr.mem.ea = insn_fetch(u64, 8, c->eip); 1033 break; 1034 } 1035 done: 1036 return rc; 1037 } 1038 1039 static void fetch_bit_operand(struct decode_cache *c) 1040 { 1041 long sv = 0, mask; 1042 1043 if (c->dst.type == OP_MEM && c->src.type == OP_REG) { 1044 mask = ~(c->dst.bytes * 8 - 1); 1045 1046 if (c->src.bytes == 2) 1047 sv = (s16)c->src.val & (s16)mask; 1048 else if (c->src.bytes == 4) 1049 sv = (s32)c->src.val & (s32)mask; 1050 1051 c->dst.addr.mem.ea += (sv >> 3); 1052 } 1053 1054 /* only subword offset */ 1055 c->src.val &= (c->dst.bytes << 3) - 1; 1056 } 1057 1058 static int read_emulated(struct x86_emulate_ctxt *ctxt, 1059 struct x86_emulate_ops *ops, 1060 unsigned long addr, void *dest, unsigned size) 1061 { 1062 int rc; 1063 struct read_cache *mc = &ctxt->decode.mem_read; 1064 1065 while (size) { 1066 int n = min(size, 8u); 1067 size -= n; 1068 if (mc->pos < mc->end) 1069 goto read_cached; 1070 1071 rc = ops->read_emulated(ctxt, addr, mc->data + mc->end, n, 1072 &ctxt->exception); 1073 if (rc != X86EMUL_CONTINUE) 1074 return rc; 1075 mc->end += n; 1076 1077 read_cached: 1078 memcpy(dest, mc->data + mc->pos, n); 1079 mc->pos += n; 1080 dest += n; 1081 addr += n; 1082 } 1083 return X86EMUL_CONTINUE; 1084 } 1085 1086 static int segmented_read(struct x86_emulate_ctxt *ctxt, 1087 struct segmented_address addr, 1088 void *data, 1089 unsigned size) 1090 { 1091 int rc; 1092 ulong linear; 1093 1094 rc = linearize(ctxt, addr, size, false, &linear); 1095 if (rc != X86EMUL_CONTINUE) 1096 return rc; 1097 return read_emulated(ctxt, ctxt->ops, linear, data, size); 1098 } 1099 1100 static int segmented_write(struct x86_emulate_ctxt *ctxt, 1101 struct segmented_address addr, 1102 const void *data, 1103 unsigned size) 1104 { 1105 int rc; 1106 ulong linear; 1107 1108 rc = linearize(ctxt, addr, size, true, &linear); 1109 if (rc != X86EMUL_CONTINUE) 1110 return rc; 1111 return ctxt->ops->write_emulated(ctxt, linear, data, size, 1112 &ctxt->exception); 1113 } 1114 1115 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt, 1116 struct segmented_address addr, 1117 const void *orig_data, const void *data, 1118 unsigned size) 1119 { 1120 int rc; 1121 ulong linear; 1122 1123 rc = linearize(ctxt, addr, size, true, &linear); 1124 if (rc != X86EMUL_CONTINUE) 1125 return rc; 1126 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data, 1127 size, &ctxt->exception); 1128 } 1129 1130 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt, 1131 struct x86_emulate_ops *ops, 1132 unsigned int size, unsigned short port, 1133 void *dest) 1134 { 1135 struct read_cache *rc = &ctxt->decode.io_read; 1136 1137 if (rc->pos == rc->end) { /* refill pio read ahead */ 1138 struct decode_cache *c = &ctxt->decode; 1139 unsigned int in_page, n; 1140 unsigned int count = c->rep_prefix ? 1141 address_mask(c, c->regs[VCPU_REGS_RCX]) : 1; 1142 in_page = (ctxt->eflags & EFLG_DF) ? 1143 offset_in_page(c->regs[VCPU_REGS_RDI]) : 1144 PAGE_SIZE - offset_in_page(c->regs[VCPU_REGS_RDI]); 1145 n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size, 1146 count); 1147 if (n == 0) 1148 n = 1; 1149 rc->pos = rc->end = 0; 1150 if (!ops->pio_in_emulated(ctxt, size, port, rc->data, n)) 1151 return 0; 1152 rc->end = n * size; 1153 } 1154 1155 memcpy(dest, rc->data + rc->pos, size); 1156 rc->pos += size; 1157 return 1; 1158 } 1159 1160 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt, 1161 struct x86_emulate_ops *ops, 1162 u16 selector, struct desc_ptr *dt) 1163 { 1164 if (selector & 1 << 2) { 1165 struct desc_struct desc; 1166 u16 sel; 1167 1168 memset (dt, 0, sizeof *dt); 1169 if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR)) 1170 return; 1171 1172 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */ 1173 dt->address = get_desc_base(&desc); 1174 } else 1175 ops->get_gdt(ctxt, dt); 1176 } 1177 1178 /* allowed just for 8 bytes segments */ 1179 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1180 struct x86_emulate_ops *ops, 1181 u16 selector, struct desc_struct *desc) 1182 { 1183 struct desc_ptr dt; 1184 u16 index = selector >> 3; 1185 int ret; 1186 ulong addr; 1187 1188 get_descriptor_table_ptr(ctxt, ops, selector, &dt); 1189 1190 if (dt.size < index * 8 + 7) 1191 return emulate_gp(ctxt, selector & 0xfffc); 1192 addr = dt.address + index * 8; 1193 ret = ops->read_std(ctxt, addr, desc, sizeof *desc, &ctxt->exception); 1194 1195 return ret; 1196 } 1197 1198 /* allowed just for 8 bytes segments */ 1199 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1200 struct x86_emulate_ops *ops, 1201 u16 selector, struct desc_struct *desc) 1202 { 1203 struct desc_ptr dt; 1204 u16 index = selector >> 3; 1205 ulong addr; 1206 int ret; 1207 1208 get_descriptor_table_ptr(ctxt, ops, selector, &dt); 1209 1210 if (dt.size < index * 8 + 7) 1211 return emulate_gp(ctxt, selector & 0xfffc); 1212 1213 addr = dt.address + index * 8; 1214 ret = ops->write_std(ctxt, addr, desc, sizeof *desc, &ctxt->exception); 1215 1216 return ret; 1217 } 1218 1219 /* Does not support long mode */ 1220 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt, 1221 struct x86_emulate_ops *ops, 1222 u16 selector, int seg) 1223 { 1224 struct desc_struct seg_desc; 1225 u8 dpl, rpl, cpl; 1226 unsigned err_vec = GP_VECTOR; 1227 u32 err_code = 0; 1228 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */ 1229 int ret; 1230 1231 memset(&seg_desc, 0, sizeof seg_desc); 1232 1233 if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) 1234 || ctxt->mode == X86EMUL_MODE_REAL) { 1235 /* set real mode segment descriptor */ 1236 set_desc_base(&seg_desc, selector << 4); 1237 set_desc_limit(&seg_desc, 0xffff); 1238 seg_desc.type = 3; 1239 seg_desc.p = 1; 1240 seg_desc.s = 1; 1241 goto load; 1242 } 1243 1244 /* NULL selector is not valid for TR, CS and SS */ 1245 if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR) 1246 && null_selector) 1247 goto exception; 1248 1249 /* TR should be in GDT only */ 1250 if (seg == VCPU_SREG_TR && (selector & (1 << 2))) 1251 goto exception; 1252 1253 if (null_selector) /* for NULL selector skip all following checks */ 1254 goto load; 1255 1256 ret = read_segment_descriptor(ctxt, ops, selector, &seg_desc); 1257 if (ret != X86EMUL_CONTINUE) 1258 return ret; 1259 1260 err_code = selector & 0xfffc; 1261 err_vec = GP_VECTOR; 1262 1263 /* can't load system descriptor into segment selecor */ 1264 if (seg <= VCPU_SREG_GS && !seg_desc.s) 1265 goto exception; 1266 1267 if (!seg_desc.p) { 1268 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR; 1269 goto exception; 1270 } 1271 1272 rpl = selector & 3; 1273 dpl = seg_desc.dpl; 1274 cpl = ops->cpl(ctxt); 1275 1276 switch (seg) { 1277 case VCPU_SREG_SS: 1278 /* 1279 * segment is not a writable data segment or segment 1280 * selector's RPL != CPL or segment selector's RPL != CPL 1281 */ 1282 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl) 1283 goto exception; 1284 break; 1285 case VCPU_SREG_CS: 1286 if (!(seg_desc.type & 8)) 1287 goto exception; 1288 1289 if (seg_desc.type & 4) { 1290 /* conforming */ 1291 if (dpl > cpl) 1292 goto exception; 1293 } else { 1294 /* nonconforming */ 1295 if (rpl > cpl || dpl != cpl) 1296 goto exception; 1297 } 1298 /* CS(RPL) <- CPL */ 1299 selector = (selector & 0xfffc) | cpl; 1300 break; 1301 case VCPU_SREG_TR: 1302 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9)) 1303 goto exception; 1304 break; 1305 case VCPU_SREG_LDTR: 1306 if (seg_desc.s || seg_desc.type != 2) 1307 goto exception; 1308 break; 1309 default: /* DS, ES, FS, or GS */ 1310 /* 1311 * segment is not a data or readable code segment or 1312 * ((segment is a data or nonconforming code segment) 1313 * and (both RPL and CPL > DPL)) 1314 */ 1315 if ((seg_desc.type & 0xa) == 0x8 || 1316 (((seg_desc.type & 0xc) != 0xc) && 1317 (rpl > dpl && cpl > dpl))) 1318 goto exception; 1319 break; 1320 } 1321 1322 if (seg_desc.s) { 1323 /* mark segment as accessed */ 1324 seg_desc.type |= 1; 1325 ret = write_segment_descriptor(ctxt, ops, selector, &seg_desc); 1326 if (ret != X86EMUL_CONTINUE) 1327 return ret; 1328 } 1329 load: 1330 ops->set_segment(ctxt, selector, &seg_desc, 0, seg); 1331 return X86EMUL_CONTINUE; 1332 exception: 1333 emulate_exception(ctxt, err_vec, err_code, true); 1334 return X86EMUL_PROPAGATE_FAULT; 1335 } 1336 1337 static void write_register_operand(struct operand *op) 1338 { 1339 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */ 1340 switch (op->bytes) { 1341 case 1: 1342 *(u8 *)op->addr.reg = (u8)op->val; 1343 break; 1344 case 2: 1345 *(u16 *)op->addr.reg = (u16)op->val; 1346 break; 1347 case 4: 1348 *op->addr.reg = (u32)op->val; 1349 break; /* 64b: zero-extend */ 1350 case 8: 1351 *op->addr.reg = op->val; 1352 break; 1353 } 1354 } 1355 1356 static int writeback(struct x86_emulate_ctxt *ctxt) 1357 { 1358 int rc; 1359 struct decode_cache *c = &ctxt->decode; 1360 1361 switch (c->dst.type) { 1362 case OP_REG: 1363 write_register_operand(&c->dst); 1364 break; 1365 case OP_MEM: 1366 if (c->lock_prefix) 1367 rc = segmented_cmpxchg(ctxt, 1368 c->dst.addr.mem, 1369 &c->dst.orig_val, 1370 &c->dst.val, 1371 c->dst.bytes); 1372 else 1373 rc = segmented_write(ctxt, 1374 c->dst.addr.mem, 1375 &c->dst.val, 1376 c->dst.bytes); 1377 if (rc != X86EMUL_CONTINUE) 1378 return rc; 1379 break; 1380 case OP_XMM: 1381 write_sse_reg(ctxt, &c->dst.vec_val, c->dst.addr.xmm); 1382 break; 1383 case OP_NONE: 1384 /* no writeback */ 1385 break; 1386 default: 1387 break; 1388 } 1389 return X86EMUL_CONTINUE; 1390 } 1391 1392 static int em_push(struct x86_emulate_ctxt *ctxt) 1393 { 1394 struct decode_cache *c = &ctxt->decode; 1395 struct segmented_address addr; 1396 1397 register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes); 1398 addr.ea = register_address(c, c->regs[VCPU_REGS_RSP]); 1399 addr.seg = VCPU_SREG_SS; 1400 1401 /* Disable writeback. */ 1402 c->dst.type = OP_NONE; 1403 return segmented_write(ctxt, addr, &c->src.val, c->op_bytes); 1404 } 1405 1406 static int emulate_pop(struct x86_emulate_ctxt *ctxt, 1407 void *dest, int len) 1408 { 1409 struct decode_cache *c = &ctxt->decode; 1410 int rc; 1411 struct segmented_address addr; 1412 1413 addr.ea = register_address(c, c->regs[VCPU_REGS_RSP]); 1414 addr.seg = VCPU_SREG_SS; 1415 rc = segmented_read(ctxt, addr, dest, len); 1416 if (rc != X86EMUL_CONTINUE) 1417 return rc; 1418 1419 register_address_increment(c, &c->regs[VCPU_REGS_RSP], len); 1420 return rc; 1421 } 1422 1423 static int em_pop(struct x86_emulate_ctxt *ctxt) 1424 { 1425 struct decode_cache *c = &ctxt->decode; 1426 1427 return emulate_pop(ctxt, &c->dst.val, c->op_bytes); 1428 } 1429 1430 static int emulate_popf(struct x86_emulate_ctxt *ctxt, 1431 struct x86_emulate_ops *ops, 1432 void *dest, int len) 1433 { 1434 int rc; 1435 unsigned long val, change_mask; 1436 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; 1437 int cpl = ops->cpl(ctxt); 1438 1439 rc = emulate_pop(ctxt, &val, len); 1440 if (rc != X86EMUL_CONTINUE) 1441 return rc; 1442 1443 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF 1444 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID; 1445 1446 switch(ctxt->mode) { 1447 case X86EMUL_MODE_PROT64: 1448 case X86EMUL_MODE_PROT32: 1449 case X86EMUL_MODE_PROT16: 1450 if (cpl == 0) 1451 change_mask |= EFLG_IOPL; 1452 if (cpl <= iopl) 1453 change_mask |= EFLG_IF; 1454 break; 1455 case X86EMUL_MODE_VM86: 1456 if (iopl < 3) 1457 return emulate_gp(ctxt, 0); 1458 change_mask |= EFLG_IF; 1459 break; 1460 default: /* real mode */ 1461 change_mask |= (EFLG_IOPL | EFLG_IF); 1462 break; 1463 } 1464 1465 *(unsigned long *)dest = 1466 (ctxt->eflags & ~change_mask) | (val & change_mask); 1467 1468 return rc; 1469 } 1470 1471 static int em_popf(struct x86_emulate_ctxt *ctxt) 1472 { 1473 struct decode_cache *c = &ctxt->decode; 1474 1475 c->dst.type = OP_REG; 1476 c->dst.addr.reg = &ctxt->eflags; 1477 c->dst.bytes = c->op_bytes; 1478 return emulate_popf(ctxt, ctxt->ops, &c->dst.val, c->op_bytes); 1479 } 1480 1481 static int emulate_push_sreg(struct x86_emulate_ctxt *ctxt, 1482 struct x86_emulate_ops *ops, int seg) 1483 { 1484 struct decode_cache *c = &ctxt->decode; 1485 1486 c->src.val = get_segment_selector(ctxt, seg); 1487 1488 return em_push(ctxt); 1489 } 1490 1491 static int emulate_pop_sreg(struct x86_emulate_ctxt *ctxt, 1492 struct x86_emulate_ops *ops, int seg) 1493 { 1494 struct decode_cache *c = &ctxt->decode; 1495 unsigned long selector; 1496 int rc; 1497 1498 rc = emulate_pop(ctxt, &selector, c->op_bytes); 1499 if (rc != X86EMUL_CONTINUE) 1500 return rc; 1501 1502 rc = load_segment_descriptor(ctxt, ops, (u16)selector, seg); 1503 return rc; 1504 } 1505 1506 static int em_pusha(struct x86_emulate_ctxt *ctxt) 1507 { 1508 struct decode_cache *c = &ctxt->decode; 1509 unsigned long old_esp = c->regs[VCPU_REGS_RSP]; 1510 int rc = X86EMUL_CONTINUE; 1511 int reg = VCPU_REGS_RAX; 1512 1513 while (reg <= VCPU_REGS_RDI) { 1514 (reg == VCPU_REGS_RSP) ? 1515 (c->src.val = old_esp) : (c->src.val = c->regs[reg]); 1516 1517 rc = em_push(ctxt); 1518 if (rc != X86EMUL_CONTINUE) 1519 return rc; 1520 1521 ++reg; 1522 } 1523 1524 return rc; 1525 } 1526 1527 static int em_pushf(struct x86_emulate_ctxt *ctxt) 1528 { 1529 struct decode_cache *c = &ctxt->decode; 1530 1531 c->src.val = (unsigned long)ctxt->eflags; 1532 return em_push(ctxt); 1533 } 1534 1535 static int em_popa(struct x86_emulate_ctxt *ctxt) 1536 { 1537 struct decode_cache *c = &ctxt->decode; 1538 int rc = X86EMUL_CONTINUE; 1539 int reg = VCPU_REGS_RDI; 1540 1541 while (reg >= VCPU_REGS_RAX) { 1542 if (reg == VCPU_REGS_RSP) { 1543 register_address_increment(c, &c->regs[VCPU_REGS_RSP], 1544 c->op_bytes); 1545 --reg; 1546 } 1547 1548 rc = emulate_pop(ctxt, &c->regs[reg], c->op_bytes); 1549 if (rc != X86EMUL_CONTINUE) 1550 break; 1551 --reg; 1552 } 1553 return rc; 1554 } 1555 1556 int emulate_int_real(struct x86_emulate_ctxt *ctxt, 1557 struct x86_emulate_ops *ops, int irq) 1558 { 1559 struct decode_cache *c = &ctxt->decode; 1560 int rc; 1561 struct desc_ptr dt; 1562 gva_t cs_addr; 1563 gva_t eip_addr; 1564 u16 cs, eip; 1565 1566 /* TODO: Add limit checks */ 1567 c->src.val = ctxt->eflags; 1568 rc = em_push(ctxt); 1569 if (rc != X86EMUL_CONTINUE) 1570 return rc; 1571 1572 ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC); 1573 1574 c->src.val = get_segment_selector(ctxt, VCPU_SREG_CS); 1575 rc = em_push(ctxt); 1576 if (rc != X86EMUL_CONTINUE) 1577 return rc; 1578 1579 c->src.val = c->eip; 1580 rc = em_push(ctxt); 1581 if (rc != X86EMUL_CONTINUE) 1582 return rc; 1583 1584 ops->get_idt(ctxt, &dt); 1585 1586 eip_addr = dt.address + (irq << 2); 1587 cs_addr = dt.address + (irq << 2) + 2; 1588 1589 rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception); 1590 if (rc != X86EMUL_CONTINUE) 1591 return rc; 1592 1593 rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception); 1594 if (rc != X86EMUL_CONTINUE) 1595 return rc; 1596 1597 rc = load_segment_descriptor(ctxt, ops, cs, VCPU_SREG_CS); 1598 if (rc != X86EMUL_CONTINUE) 1599 return rc; 1600 1601 c->eip = eip; 1602 1603 return rc; 1604 } 1605 1606 static int emulate_int(struct x86_emulate_ctxt *ctxt, 1607 struct x86_emulate_ops *ops, int irq) 1608 { 1609 switch(ctxt->mode) { 1610 case X86EMUL_MODE_REAL: 1611 return emulate_int_real(ctxt, ops, irq); 1612 case X86EMUL_MODE_VM86: 1613 case X86EMUL_MODE_PROT16: 1614 case X86EMUL_MODE_PROT32: 1615 case X86EMUL_MODE_PROT64: 1616 default: 1617 /* Protected mode interrupts unimplemented yet */ 1618 return X86EMUL_UNHANDLEABLE; 1619 } 1620 } 1621 1622 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt, 1623 struct x86_emulate_ops *ops) 1624 { 1625 struct decode_cache *c = &ctxt->decode; 1626 int rc = X86EMUL_CONTINUE; 1627 unsigned long temp_eip = 0; 1628 unsigned long temp_eflags = 0; 1629 unsigned long cs = 0; 1630 unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF | 1631 EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF | 1632 EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */ 1633 unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP; 1634 1635 /* TODO: Add stack limit check */ 1636 1637 rc = emulate_pop(ctxt, &temp_eip, c->op_bytes); 1638 1639 if (rc != X86EMUL_CONTINUE) 1640 return rc; 1641 1642 if (temp_eip & ~0xffff) 1643 return emulate_gp(ctxt, 0); 1644 1645 rc = emulate_pop(ctxt, &cs, c->op_bytes); 1646 1647 if (rc != X86EMUL_CONTINUE) 1648 return rc; 1649 1650 rc = emulate_pop(ctxt, &temp_eflags, c->op_bytes); 1651 1652 if (rc != X86EMUL_CONTINUE) 1653 return rc; 1654 1655 rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS); 1656 1657 if (rc != X86EMUL_CONTINUE) 1658 return rc; 1659 1660 c->eip = temp_eip; 1661 1662 1663 if (c->op_bytes == 4) 1664 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask)); 1665 else if (c->op_bytes == 2) { 1666 ctxt->eflags &= ~0xffff; 1667 ctxt->eflags |= temp_eflags; 1668 } 1669 1670 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */ 1671 ctxt->eflags |= EFLG_RESERVED_ONE_MASK; 1672 1673 return rc; 1674 } 1675 1676 static inline int emulate_iret(struct x86_emulate_ctxt *ctxt, 1677 struct x86_emulate_ops* ops) 1678 { 1679 switch(ctxt->mode) { 1680 case X86EMUL_MODE_REAL: 1681 return emulate_iret_real(ctxt, ops); 1682 case X86EMUL_MODE_VM86: 1683 case X86EMUL_MODE_PROT16: 1684 case X86EMUL_MODE_PROT32: 1685 case X86EMUL_MODE_PROT64: 1686 default: 1687 /* iret from protected mode unimplemented yet */ 1688 return X86EMUL_UNHANDLEABLE; 1689 } 1690 } 1691 1692 static int em_jmp_far(struct x86_emulate_ctxt *ctxt) 1693 { 1694 struct decode_cache *c = &ctxt->decode; 1695 int rc; 1696 unsigned short sel; 1697 1698 memcpy(&sel, c->src.valptr + c->op_bytes, 2); 1699 1700 rc = load_segment_descriptor(ctxt, ctxt->ops, sel, VCPU_SREG_CS); 1701 if (rc != X86EMUL_CONTINUE) 1702 return rc; 1703 1704 c->eip = 0; 1705 memcpy(&c->eip, c->src.valptr, c->op_bytes); 1706 return X86EMUL_CONTINUE; 1707 } 1708 1709 static int em_grp1a(struct x86_emulate_ctxt *ctxt) 1710 { 1711 struct decode_cache *c = &ctxt->decode; 1712 1713 return emulate_pop(ctxt, &c->dst.val, c->dst.bytes); 1714 } 1715 1716 static int em_grp2(struct x86_emulate_ctxt *ctxt) 1717 { 1718 struct decode_cache *c = &ctxt->decode; 1719 switch (c->modrm_reg) { 1720 case 0: /* rol */ 1721 emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags); 1722 break; 1723 case 1: /* ror */ 1724 emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags); 1725 break; 1726 case 2: /* rcl */ 1727 emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags); 1728 break; 1729 case 3: /* rcr */ 1730 emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags); 1731 break; 1732 case 4: /* sal/shl */ 1733 case 6: /* sal/shl */ 1734 emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags); 1735 break; 1736 case 5: /* shr */ 1737 emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags); 1738 break; 1739 case 7: /* sar */ 1740 emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags); 1741 break; 1742 } 1743 return X86EMUL_CONTINUE; 1744 } 1745 1746 static int em_grp3(struct x86_emulate_ctxt *ctxt) 1747 { 1748 struct decode_cache *c = &ctxt->decode; 1749 unsigned long *rax = &c->regs[VCPU_REGS_RAX]; 1750 unsigned long *rdx = &c->regs[VCPU_REGS_RDX]; 1751 u8 de = 0; 1752 1753 switch (c->modrm_reg) { 1754 case 0 ... 1: /* test */ 1755 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); 1756 break; 1757 case 2: /* not */ 1758 c->dst.val = ~c->dst.val; 1759 break; 1760 case 3: /* neg */ 1761 emulate_1op("neg", c->dst, ctxt->eflags); 1762 break; 1763 case 4: /* mul */ 1764 emulate_1op_rax_rdx("mul", c->src, *rax, *rdx, ctxt->eflags); 1765 break; 1766 case 5: /* imul */ 1767 emulate_1op_rax_rdx("imul", c->src, *rax, *rdx, ctxt->eflags); 1768 break; 1769 case 6: /* div */ 1770 emulate_1op_rax_rdx_ex("div", c->src, *rax, *rdx, 1771 ctxt->eflags, de); 1772 break; 1773 case 7: /* idiv */ 1774 emulate_1op_rax_rdx_ex("idiv", c->src, *rax, *rdx, 1775 ctxt->eflags, de); 1776 break; 1777 default: 1778 return X86EMUL_UNHANDLEABLE; 1779 } 1780 if (de) 1781 return emulate_de(ctxt); 1782 return X86EMUL_CONTINUE; 1783 } 1784 1785 static int em_grp45(struct x86_emulate_ctxt *ctxt) 1786 { 1787 struct decode_cache *c = &ctxt->decode; 1788 int rc = X86EMUL_CONTINUE; 1789 1790 switch (c->modrm_reg) { 1791 case 0: /* inc */ 1792 emulate_1op("inc", c->dst, ctxt->eflags); 1793 break; 1794 case 1: /* dec */ 1795 emulate_1op("dec", c->dst, ctxt->eflags); 1796 break; 1797 case 2: /* call near abs */ { 1798 long int old_eip; 1799 old_eip = c->eip; 1800 c->eip = c->src.val; 1801 c->src.val = old_eip; 1802 rc = em_push(ctxt); 1803 break; 1804 } 1805 case 4: /* jmp abs */ 1806 c->eip = c->src.val; 1807 break; 1808 case 5: /* jmp far */ 1809 rc = em_jmp_far(ctxt); 1810 break; 1811 case 6: /* push */ 1812 rc = em_push(ctxt); 1813 break; 1814 } 1815 return rc; 1816 } 1817 1818 static int em_grp9(struct x86_emulate_ctxt *ctxt) 1819 { 1820 struct decode_cache *c = &ctxt->decode; 1821 u64 old = c->dst.orig_val64; 1822 1823 if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) || 1824 ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) { 1825 c->regs[VCPU_REGS_RAX] = (u32) (old >> 0); 1826 c->regs[VCPU_REGS_RDX] = (u32) (old >> 32); 1827 ctxt->eflags &= ~EFLG_ZF; 1828 } else { 1829 c->dst.val64 = ((u64)c->regs[VCPU_REGS_RCX] << 32) | 1830 (u32) c->regs[VCPU_REGS_RBX]; 1831 1832 ctxt->eflags |= EFLG_ZF; 1833 } 1834 return X86EMUL_CONTINUE; 1835 } 1836 1837 static int emulate_ret_far(struct x86_emulate_ctxt *ctxt, 1838 struct x86_emulate_ops *ops) 1839 { 1840 struct decode_cache *c = &ctxt->decode; 1841 int rc; 1842 unsigned long cs; 1843 1844 rc = emulate_pop(ctxt, &c->eip, c->op_bytes); 1845 if (rc != X86EMUL_CONTINUE) 1846 return rc; 1847 if (c->op_bytes == 4) 1848 c->eip = (u32)c->eip; 1849 rc = emulate_pop(ctxt, &cs, c->op_bytes); 1850 if (rc != X86EMUL_CONTINUE) 1851 return rc; 1852 rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS); 1853 return rc; 1854 } 1855 1856 static int emulate_load_segment(struct x86_emulate_ctxt *ctxt, 1857 struct x86_emulate_ops *ops, int seg) 1858 { 1859 struct decode_cache *c = &ctxt->decode; 1860 unsigned short sel; 1861 int rc; 1862 1863 memcpy(&sel, c->src.valptr + c->op_bytes, 2); 1864 1865 rc = load_segment_descriptor(ctxt, ops, sel, seg); 1866 if (rc != X86EMUL_CONTINUE) 1867 return rc; 1868 1869 c->dst.val = c->src.val; 1870 return rc; 1871 } 1872 1873 static inline void 1874 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, 1875 struct x86_emulate_ops *ops, struct desc_struct *cs, 1876 struct desc_struct *ss) 1877 { 1878 u16 selector; 1879 1880 memset(cs, 0, sizeof(struct desc_struct)); 1881 ops->get_segment(ctxt, &selector, cs, NULL, VCPU_SREG_CS); 1882 memset(ss, 0, sizeof(struct desc_struct)); 1883 1884 cs->l = 0; /* will be adjusted later */ 1885 set_desc_base(cs, 0); /* flat segment */ 1886 cs->g = 1; /* 4kb granularity */ 1887 set_desc_limit(cs, 0xfffff); /* 4GB limit */ 1888 cs->type = 0x0b; /* Read, Execute, Accessed */ 1889 cs->s = 1; 1890 cs->dpl = 0; /* will be adjusted later */ 1891 cs->p = 1; 1892 cs->d = 1; 1893 1894 set_desc_base(ss, 0); /* flat segment */ 1895 set_desc_limit(ss, 0xfffff); /* 4GB limit */ 1896 ss->g = 1; /* 4kb granularity */ 1897 ss->s = 1; 1898 ss->type = 0x03; /* Read/Write, Accessed */ 1899 ss->d = 1; /* 32bit stack segment */ 1900 ss->dpl = 0; 1901 ss->p = 1; 1902 } 1903 1904 static int 1905 emulate_syscall(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 1906 { 1907 struct decode_cache *c = &ctxt->decode; 1908 struct desc_struct cs, ss; 1909 u64 msr_data; 1910 u16 cs_sel, ss_sel; 1911 u64 efer = 0; 1912 1913 /* syscall is not available in real mode */ 1914 if (ctxt->mode == X86EMUL_MODE_REAL || 1915 ctxt->mode == X86EMUL_MODE_VM86) 1916 return emulate_ud(ctxt); 1917 1918 ops->get_msr(ctxt, MSR_EFER, &efer); 1919 setup_syscalls_segments(ctxt, ops, &cs, &ss); 1920 1921 ops->get_msr(ctxt, MSR_STAR, &msr_data); 1922 msr_data >>= 32; 1923 cs_sel = (u16)(msr_data & 0xfffc); 1924 ss_sel = (u16)(msr_data + 8); 1925 1926 if (efer & EFER_LMA) { 1927 cs.d = 0; 1928 cs.l = 1; 1929 } 1930 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 1931 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 1932 1933 c->regs[VCPU_REGS_RCX] = c->eip; 1934 if (efer & EFER_LMA) { 1935 #ifdef CONFIG_X86_64 1936 c->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF; 1937 1938 ops->get_msr(ctxt, 1939 ctxt->mode == X86EMUL_MODE_PROT64 ? 1940 MSR_LSTAR : MSR_CSTAR, &msr_data); 1941 c->eip = msr_data; 1942 1943 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data); 1944 ctxt->eflags &= ~(msr_data | EFLG_RF); 1945 #endif 1946 } else { 1947 /* legacy mode */ 1948 ops->get_msr(ctxt, MSR_STAR, &msr_data); 1949 c->eip = (u32)msr_data; 1950 1951 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); 1952 } 1953 1954 return X86EMUL_CONTINUE; 1955 } 1956 1957 static int 1958 emulate_sysenter(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 1959 { 1960 struct decode_cache *c = &ctxt->decode; 1961 struct desc_struct cs, ss; 1962 u64 msr_data; 1963 u16 cs_sel, ss_sel; 1964 u64 efer = 0; 1965 1966 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 1967 /* inject #GP if in real mode */ 1968 if (ctxt->mode == X86EMUL_MODE_REAL) 1969 return emulate_gp(ctxt, 0); 1970 1971 /* XXX sysenter/sysexit have not been tested in 64bit mode. 1972 * Therefore, we inject an #UD. 1973 */ 1974 if (ctxt->mode == X86EMUL_MODE_PROT64) 1975 return emulate_ud(ctxt); 1976 1977 setup_syscalls_segments(ctxt, ops, &cs, &ss); 1978 1979 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); 1980 switch (ctxt->mode) { 1981 case X86EMUL_MODE_PROT32: 1982 if ((msr_data & 0xfffc) == 0x0) 1983 return emulate_gp(ctxt, 0); 1984 break; 1985 case X86EMUL_MODE_PROT64: 1986 if (msr_data == 0x0) 1987 return emulate_gp(ctxt, 0); 1988 break; 1989 } 1990 1991 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); 1992 cs_sel = (u16)msr_data; 1993 cs_sel &= ~SELECTOR_RPL_MASK; 1994 ss_sel = cs_sel + 8; 1995 ss_sel &= ~SELECTOR_RPL_MASK; 1996 if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) { 1997 cs.d = 0; 1998 cs.l = 1; 1999 } 2000 2001 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2002 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2003 2004 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data); 2005 c->eip = msr_data; 2006 2007 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data); 2008 c->regs[VCPU_REGS_RSP] = msr_data; 2009 2010 return X86EMUL_CONTINUE; 2011 } 2012 2013 static int 2014 emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) 2015 { 2016 struct decode_cache *c = &ctxt->decode; 2017 struct desc_struct cs, ss; 2018 u64 msr_data; 2019 int usermode; 2020 u16 cs_sel, ss_sel; 2021 2022 /* inject #GP if in real mode or Virtual 8086 mode */ 2023 if (ctxt->mode == X86EMUL_MODE_REAL || 2024 ctxt->mode == X86EMUL_MODE_VM86) 2025 return emulate_gp(ctxt, 0); 2026 2027 setup_syscalls_segments(ctxt, ops, &cs, &ss); 2028 2029 if ((c->rex_prefix & 0x8) != 0x0) 2030 usermode = X86EMUL_MODE_PROT64; 2031 else 2032 usermode = X86EMUL_MODE_PROT32; 2033 2034 cs.dpl = 3; 2035 ss.dpl = 3; 2036 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data); 2037 switch (usermode) { 2038 case X86EMUL_MODE_PROT32: 2039 cs_sel = (u16)(msr_data + 16); 2040 if ((msr_data & 0xfffc) == 0x0) 2041 return emulate_gp(ctxt, 0); 2042 ss_sel = (u16)(msr_data + 24); 2043 break; 2044 case X86EMUL_MODE_PROT64: 2045 cs_sel = (u16)(msr_data + 32); 2046 if (msr_data == 0x0) 2047 return emulate_gp(ctxt, 0); 2048 ss_sel = cs_sel + 8; 2049 cs.d = 0; 2050 cs.l = 1; 2051 break; 2052 } 2053 cs_sel |= SELECTOR_RPL_MASK; 2054 ss_sel |= SELECTOR_RPL_MASK; 2055 2056 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS); 2057 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS); 2058 2059 c->eip = c->regs[VCPU_REGS_RDX]; 2060 c->regs[VCPU_REGS_RSP] = c->regs[VCPU_REGS_RCX]; 2061 2062 return X86EMUL_CONTINUE; 2063 } 2064 2065 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt, 2066 struct x86_emulate_ops *ops) 2067 { 2068 int iopl; 2069 if (ctxt->mode == X86EMUL_MODE_REAL) 2070 return false; 2071 if (ctxt->mode == X86EMUL_MODE_VM86) 2072 return true; 2073 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT; 2074 return ops->cpl(ctxt) > iopl; 2075 } 2076 2077 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt, 2078 struct x86_emulate_ops *ops, 2079 u16 port, u16 len) 2080 { 2081 struct desc_struct tr_seg; 2082 u32 base3; 2083 int r; 2084 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7; 2085 unsigned mask = (1 << len) - 1; 2086 unsigned long base; 2087 2088 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR); 2089 if (!tr_seg.p) 2090 return false; 2091 if (desc_limit_scaled(&tr_seg) < 103) 2092 return false; 2093 base = get_desc_base(&tr_seg); 2094 #ifdef CONFIG_X86_64 2095 base |= ((u64)base3) << 32; 2096 #endif 2097 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL); 2098 if (r != X86EMUL_CONTINUE) 2099 return false; 2100 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg)) 2101 return false; 2102 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL); 2103 if (r != X86EMUL_CONTINUE) 2104 return false; 2105 if ((perm >> bit_idx) & mask) 2106 return false; 2107 return true; 2108 } 2109 2110 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt, 2111 struct x86_emulate_ops *ops, 2112 u16 port, u16 len) 2113 { 2114 if (ctxt->perm_ok) 2115 return true; 2116 2117 if (emulator_bad_iopl(ctxt, ops)) 2118 if (!emulator_io_port_access_allowed(ctxt, ops, port, len)) 2119 return false; 2120 2121 ctxt->perm_ok = true; 2122 2123 return true; 2124 } 2125 2126 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt, 2127 struct x86_emulate_ops *ops, 2128 struct tss_segment_16 *tss) 2129 { 2130 struct decode_cache *c = &ctxt->decode; 2131 2132 tss->ip = c->eip; 2133 tss->flag = ctxt->eflags; 2134 tss->ax = c->regs[VCPU_REGS_RAX]; 2135 tss->cx = c->regs[VCPU_REGS_RCX]; 2136 tss->dx = c->regs[VCPU_REGS_RDX]; 2137 tss->bx = c->regs[VCPU_REGS_RBX]; 2138 tss->sp = c->regs[VCPU_REGS_RSP]; 2139 tss->bp = c->regs[VCPU_REGS_RBP]; 2140 tss->si = c->regs[VCPU_REGS_RSI]; 2141 tss->di = c->regs[VCPU_REGS_RDI]; 2142 2143 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); 2144 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); 2145 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); 2146 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); 2147 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR); 2148 } 2149 2150 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt, 2151 struct x86_emulate_ops *ops, 2152 struct tss_segment_16 *tss) 2153 { 2154 struct decode_cache *c = &ctxt->decode; 2155 int ret; 2156 2157 c->eip = tss->ip; 2158 ctxt->eflags = tss->flag | 2; 2159 c->regs[VCPU_REGS_RAX] = tss->ax; 2160 c->regs[VCPU_REGS_RCX] = tss->cx; 2161 c->regs[VCPU_REGS_RDX] = tss->dx; 2162 c->regs[VCPU_REGS_RBX] = tss->bx; 2163 c->regs[VCPU_REGS_RSP] = tss->sp; 2164 c->regs[VCPU_REGS_RBP] = tss->bp; 2165 c->regs[VCPU_REGS_RSI] = tss->si; 2166 c->regs[VCPU_REGS_RDI] = tss->di; 2167 2168 /* 2169 * SDM says that segment selectors are loaded before segment 2170 * descriptors 2171 */ 2172 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR); 2173 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); 2174 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); 2175 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); 2176 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); 2177 2178 /* 2179 * Now load segment descriptors. If fault happenes at this stage 2180 * it is handled in a context of new task 2181 */ 2182 ret = load_segment_descriptor(ctxt, ops, tss->ldt, VCPU_SREG_LDTR); 2183 if (ret != X86EMUL_CONTINUE) 2184 return ret; 2185 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES); 2186 if (ret != X86EMUL_CONTINUE) 2187 return ret; 2188 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS); 2189 if (ret != X86EMUL_CONTINUE) 2190 return ret; 2191 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS); 2192 if (ret != X86EMUL_CONTINUE) 2193 return ret; 2194 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS); 2195 if (ret != X86EMUL_CONTINUE) 2196 return ret; 2197 2198 return X86EMUL_CONTINUE; 2199 } 2200 2201 static int task_switch_16(struct x86_emulate_ctxt *ctxt, 2202 struct x86_emulate_ops *ops, 2203 u16 tss_selector, u16 old_tss_sel, 2204 ulong old_tss_base, struct desc_struct *new_desc) 2205 { 2206 struct tss_segment_16 tss_seg; 2207 int ret; 2208 u32 new_tss_base = get_desc_base(new_desc); 2209 2210 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, 2211 &ctxt->exception); 2212 if (ret != X86EMUL_CONTINUE) 2213 /* FIXME: need to provide precise fault address */ 2214 return ret; 2215 2216 save_state_to_tss16(ctxt, ops, &tss_seg); 2217 2218 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, 2219 &ctxt->exception); 2220 if (ret != X86EMUL_CONTINUE) 2221 /* FIXME: need to provide precise fault address */ 2222 return ret; 2223 2224 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg, 2225 &ctxt->exception); 2226 if (ret != X86EMUL_CONTINUE) 2227 /* FIXME: need to provide precise fault address */ 2228 return ret; 2229 2230 if (old_tss_sel != 0xffff) { 2231 tss_seg.prev_task_link = old_tss_sel; 2232 2233 ret = ops->write_std(ctxt, new_tss_base, 2234 &tss_seg.prev_task_link, 2235 sizeof tss_seg.prev_task_link, 2236 &ctxt->exception); 2237 if (ret != X86EMUL_CONTINUE) 2238 /* FIXME: need to provide precise fault address */ 2239 return ret; 2240 } 2241 2242 return load_state_from_tss16(ctxt, ops, &tss_seg); 2243 } 2244 2245 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt, 2246 struct x86_emulate_ops *ops, 2247 struct tss_segment_32 *tss) 2248 { 2249 struct decode_cache *c = &ctxt->decode; 2250 2251 tss->cr3 = ops->get_cr(ctxt, 3); 2252 tss->eip = c->eip; 2253 tss->eflags = ctxt->eflags; 2254 tss->eax = c->regs[VCPU_REGS_RAX]; 2255 tss->ecx = c->regs[VCPU_REGS_RCX]; 2256 tss->edx = c->regs[VCPU_REGS_RDX]; 2257 tss->ebx = c->regs[VCPU_REGS_RBX]; 2258 tss->esp = c->regs[VCPU_REGS_RSP]; 2259 tss->ebp = c->regs[VCPU_REGS_RBP]; 2260 tss->esi = c->regs[VCPU_REGS_RSI]; 2261 tss->edi = c->regs[VCPU_REGS_RDI]; 2262 2263 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES); 2264 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS); 2265 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS); 2266 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS); 2267 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS); 2268 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS); 2269 tss->ldt_selector = get_segment_selector(ctxt, VCPU_SREG_LDTR); 2270 } 2271 2272 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt, 2273 struct x86_emulate_ops *ops, 2274 struct tss_segment_32 *tss) 2275 { 2276 struct decode_cache *c = &ctxt->decode; 2277 int ret; 2278 2279 if (ops->set_cr(ctxt, 3, tss->cr3)) 2280 return emulate_gp(ctxt, 0); 2281 c->eip = tss->eip; 2282 ctxt->eflags = tss->eflags | 2; 2283 c->regs[VCPU_REGS_RAX] = tss->eax; 2284 c->regs[VCPU_REGS_RCX] = tss->ecx; 2285 c->regs[VCPU_REGS_RDX] = tss->edx; 2286 c->regs[VCPU_REGS_RBX] = tss->ebx; 2287 c->regs[VCPU_REGS_RSP] = tss->esp; 2288 c->regs[VCPU_REGS_RBP] = tss->ebp; 2289 c->regs[VCPU_REGS_RSI] = tss->esi; 2290 c->regs[VCPU_REGS_RDI] = tss->edi; 2291 2292 /* 2293 * SDM says that segment selectors are loaded before segment 2294 * descriptors 2295 */ 2296 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR); 2297 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES); 2298 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS); 2299 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS); 2300 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS); 2301 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS); 2302 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS); 2303 2304 /* 2305 * Now load segment descriptors. If fault happenes at this stage 2306 * it is handled in a context of new task 2307 */ 2308 ret = load_segment_descriptor(ctxt, ops, tss->ldt_selector, VCPU_SREG_LDTR); 2309 if (ret != X86EMUL_CONTINUE) 2310 return ret; 2311 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES); 2312 if (ret != X86EMUL_CONTINUE) 2313 return ret; 2314 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS); 2315 if (ret != X86EMUL_CONTINUE) 2316 return ret; 2317 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS); 2318 if (ret != X86EMUL_CONTINUE) 2319 return ret; 2320 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS); 2321 if (ret != X86EMUL_CONTINUE) 2322 return ret; 2323 ret = load_segment_descriptor(ctxt, ops, tss->fs, VCPU_SREG_FS); 2324 if (ret != X86EMUL_CONTINUE) 2325 return ret; 2326 ret = load_segment_descriptor(ctxt, ops, tss->gs, VCPU_SREG_GS); 2327 if (ret != X86EMUL_CONTINUE) 2328 return ret; 2329 2330 return X86EMUL_CONTINUE; 2331 } 2332 2333 static int task_switch_32(struct x86_emulate_ctxt *ctxt, 2334 struct x86_emulate_ops *ops, 2335 u16 tss_selector, u16 old_tss_sel, 2336 ulong old_tss_base, struct desc_struct *new_desc) 2337 { 2338 struct tss_segment_32 tss_seg; 2339 int ret; 2340 u32 new_tss_base = get_desc_base(new_desc); 2341 2342 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, 2343 &ctxt->exception); 2344 if (ret != X86EMUL_CONTINUE) 2345 /* FIXME: need to provide precise fault address */ 2346 return ret; 2347 2348 save_state_to_tss32(ctxt, ops, &tss_seg); 2349 2350 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg, 2351 &ctxt->exception); 2352 if (ret != X86EMUL_CONTINUE) 2353 /* FIXME: need to provide precise fault address */ 2354 return ret; 2355 2356 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg, 2357 &ctxt->exception); 2358 if (ret != X86EMUL_CONTINUE) 2359 /* FIXME: need to provide precise fault address */ 2360 return ret; 2361 2362 if (old_tss_sel != 0xffff) { 2363 tss_seg.prev_task_link = old_tss_sel; 2364 2365 ret = ops->write_std(ctxt, new_tss_base, 2366 &tss_seg.prev_task_link, 2367 sizeof tss_seg.prev_task_link, 2368 &ctxt->exception); 2369 if (ret != X86EMUL_CONTINUE) 2370 /* FIXME: need to provide precise fault address */ 2371 return ret; 2372 } 2373 2374 return load_state_from_tss32(ctxt, ops, &tss_seg); 2375 } 2376 2377 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt, 2378 struct x86_emulate_ops *ops, 2379 u16 tss_selector, int reason, 2380 bool has_error_code, u32 error_code) 2381 { 2382 struct desc_struct curr_tss_desc, next_tss_desc; 2383 int ret; 2384 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR); 2385 ulong old_tss_base = 2386 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR); 2387 u32 desc_limit; 2388 2389 /* FIXME: old_tss_base == ~0 ? */ 2390 2391 ret = read_segment_descriptor(ctxt, ops, tss_selector, &next_tss_desc); 2392 if (ret != X86EMUL_CONTINUE) 2393 return ret; 2394 ret = read_segment_descriptor(ctxt, ops, old_tss_sel, &curr_tss_desc); 2395 if (ret != X86EMUL_CONTINUE) 2396 return ret; 2397 2398 /* FIXME: check that next_tss_desc is tss */ 2399 2400 if (reason != TASK_SWITCH_IRET) { 2401 if ((tss_selector & 3) > next_tss_desc.dpl || 2402 ops->cpl(ctxt) > next_tss_desc.dpl) 2403 return emulate_gp(ctxt, 0); 2404 } 2405 2406 desc_limit = desc_limit_scaled(&next_tss_desc); 2407 if (!next_tss_desc.p || 2408 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) || 2409 desc_limit < 0x2b)) { 2410 emulate_ts(ctxt, tss_selector & 0xfffc); 2411 return X86EMUL_PROPAGATE_FAULT; 2412 } 2413 2414 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) { 2415 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */ 2416 write_segment_descriptor(ctxt, ops, old_tss_sel, 2417 &curr_tss_desc); 2418 } 2419 2420 if (reason == TASK_SWITCH_IRET) 2421 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT; 2422 2423 /* set back link to prev task only if NT bit is set in eflags 2424 note that old_tss_sel is not used afetr this point */ 2425 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE) 2426 old_tss_sel = 0xffff; 2427 2428 if (next_tss_desc.type & 8) 2429 ret = task_switch_32(ctxt, ops, tss_selector, old_tss_sel, 2430 old_tss_base, &next_tss_desc); 2431 else 2432 ret = task_switch_16(ctxt, ops, tss_selector, old_tss_sel, 2433 old_tss_base, &next_tss_desc); 2434 if (ret != X86EMUL_CONTINUE) 2435 return ret; 2436 2437 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE) 2438 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT; 2439 2440 if (reason != TASK_SWITCH_IRET) { 2441 next_tss_desc.type |= (1 << 1); /* set busy flag */ 2442 write_segment_descriptor(ctxt, ops, tss_selector, 2443 &next_tss_desc); 2444 } 2445 2446 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS); 2447 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR); 2448 2449 if (has_error_code) { 2450 struct decode_cache *c = &ctxt->decode; 2451 2452 c->op_bytes = c->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2; 2453 c->lock_prefix = 0; 2454 c->src.val = (unsigned long) error_code; 2455 ret = em_push(ctxt); 2456 } 2457 2458 return ret; 2459 } 2460 2461 int emulator_task_switch(struct x86_emulate_ctxt *ctxt, 2462 u16 tss_selector, int reason, 2463 bool has_error_code, u32 error_code) 2464 { 2465 struct x86_emulate_ops *ops = ctxt->ops; 2466 struct decode_cache *c = &ctxt->decode; 2467 int rc; 2468 2469 c->eip = ctxt->eip; 2470 c->dst.type = OP_NONE; 2471 2472 rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason, 2473 has_error_code, error_code); 2474 2475 if (rc == X86EMUL_CONTINUE) 2476 ctxt->eip = c->eip; 2477 2478 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 2479 } 2480 2481 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned seg, 2482 int reg, struct operand *op) 2483 { 2484 struct decode_cache *c = &ctxt->decode; 2485 int df = (ctxt->eflags & EFLG_DF) ? -1 : 1; 2486 2487 register_address_increment(c, &c->regs[reg], df * op->bytes); 2488 op->addr.mem.ea = register_address(c, c->regs[reg]); 2489 op->addr.mem.seg = seg; 2490 } 2491 2492 static int em_das(struct x86_emulate_ctxt *ctxt) 2493 { 2494 struct decode_cache *c = &ctxt->decode; 2495 u8 al, old_al; 2496 bool af, cf, old_cf; 2497 2498 cf = ctxt->eflags & X86_EFLAGS_CF; 2499 al = c->dst.val; 2500 2501 old_al = al; 2502 old_cf = cf; 2503 cf = false; 2504 af = ctxt->eflags & X86_EFLAGS_AF; 2505 if ((al & 0x0f) > 9 || af) { 2506 al -= 6; 2507 cf = old_cf | (al >= 250); 2508 af = true; 2509 } else { 2510 af = false; 2511 } 2512 if (old_al > 0x99 || old_cf) { 2513 al -= 0x60; 2514 cf = true; 2515 } 2516 2517 c->dst.val = al; 2518 /* Set PF, ZF, SF */ 2519 c->src.type = OP_IMM; 2520 c->src.val = 0; 2521 c->src.bytes = 1; 2522 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags); 2523 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF); 2524 if (cf) 2525 ctxt->eflags |= X86_EFLAGS_CF; 2526 if (af) 2527 ctxt->eflags |= X86_EFLAGS_AF; 2528 return X86EMUL_CONTINUE; 2529 } 2530 2531 static int em_call_far(struct x86_emulate_ctxt *ctxt) 2532 { 2533 struct decode_cache *c = &ctxt->decode; 2534 u16 sel, old_cs; 2535 ulong old_eip; 2536 int rc; 2537 2538 old_cs = get_segment_selector(ctxt, VCPU_SREG_CS); 2539 old_eip = c->eip; 2540 2541 memcpy(&sel, c->src.valptr + c->op_bytes, 2); 2542 if (load_segment_descriptor(ctxt, ctxt->ops, sel, VCPU_SREG_CS)) 2543 return X86EMUL_CONTINUE; 2544 2545 c->eip = 0; 2546 memcpy(&c->eip, c->src.valptr, c->op_bytes); 2547 2548 c->src.val = old_cs; 2549 rc = em_push(ctxt); 2550 if (rc != X86EMUL_CONTINUE) 2551 return rc; 2552 2553 c->src.val = old_eip; 2554 return em_push(ctxt); 2555 } 2556 2557 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt) 2558 { 2559 struct decode_cache *c = &ctxt->decode; 2560 int rc; 2561 2562 c->dst.type = OP_REG; 2563 c->dst.addr.reg = &c->eip; 2564 c->dst.bytes = c->op_bytes; 2565 rc = emulate_pop(ctxt, &c->dst.val, c->op_bytes); 2566 if (rc != X86EMUL_CONTINUE) 2567 return rc; 2568 register_address_increment(c, &c->regs[VCPU_REGS_RSP], c->src.val); 2569 return X86EMUL_CONTINUE; 2570 } 2571 2572 static int em_add(struct x86_emulate_ctxt *ctxt) 2573 { 2574 struct decode_cache *c = &ctxt->decode; 2575 2576 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags); 2577 return X86EMUL_CONTINUE; 2578 } 2579 2580 static int em_or(struct x86_emulate_ctxt *ctxt) 2581 { 2582 struct decode_cache *c = &ctxt->decode; 2583 2584 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags); 2585 return X86EMUL_CONTINUE; 2586 } 2587 2588 static int em_adc(struct x86_emulate_ctxt *ctxt) 2589 { 2590 struct decode_cache *c = &ctxt->decode; 2591 2592 emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags); 2593 return X86EMUL_CONTINUE; 2594 } 2595 2596 static int em_sbb(struct x86_emulate_ctxt *ctxt) 2597 { 2598 struct decode_cache *c = &ctxt->decode; 2599 2600 emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags); 2601 return X86EMUL_CONTINUE; 2602 } 2603 2604 static int em_and(struct x86_emulate_ctxt *ctxt) 2605 { 2606 struct decode_cache *c = &ctxt->decode; 2607 2608 emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags); 2609 return X86EMUL_CONTINUE; 2610 } 2611 2612 static int em_sub(struct x86_emulate_ctxt *ctxt) 2613 { 2614 struct decode_cache *c = &ctxt->decode; 2615 2616 emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags); 2617 return X86EMUL_CONTINUE; 2618 } 2619 2620 static int em_xor(struct x86_emulate_ctxt *ctxt) 2621 { 2622 struct decode_cache *c = &ctxt->decode; 2623 2624 emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags); 2625 return X86EMUL_CONTINUE; 2626 } 2627 2628 static int em_cmp(struct x86_emulate_ctxt *ctxt) 2629 { 2630 struct decode_cache *c = &ctxt->decode; 2631 2632 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); 2633 /* Disable writeback. */ 2634 c->dst.type = OP_NONE; 2635 return X86EMUL_CONTINUE; 2636 } 2637 2638 static int em_imul(struct x86_emulate_ctxt *ctxt) 2639 { 2640 struct decode_cache *c = &ctxt->decode; 2641 2642 emulate_2op_SrcV_nobyte("imul", c->src, c->dst, ctxt->eflags); 2643 return X86EMUL_CONTINUE; 2644 } 2645 2646 static int em_imul_3op(struct x86_emulate_ctxt *ctxt) 2647 { 2648 struct decode_cache *c = &ctxt->decode; 2649 2650 c->dst.val = c->src2.val; 2651 return em_imul(ctxt); 2652 } 2653 2654 static int em_cwd(struct x86_emulate_ctxt *ctxt) 2655 { 2656 struct decode_cache *c = &ctxt->decode; 2657 2658 c->dst.type = OP_REG; 2659 c->dst.bytes = c->src.bytes; 2660 c->dst.addr.reg = &c->regs[VCPU_REGS_RDX]; 2661 c->dst.val = ~((c->src.val >> (c->src.bytes * 8 - 1)) - 1); 2662 2663 return X86EMUL_CONTINUE; 2664 } 2665 2666 static int em_rdtsc(struct x86_emulate_ctxt *ctxt) 2667 { 2668 struct decode_cache *c = &ctxt->decode; 2669 u64 tsc = 0; 2670 2671 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc); 2672 c->regs[VCPU_REGS_RAX] = (u32)tsc; 2673 c->regs[VCPU_REGS_RDX] = tsc >> 32; 2674 return X86EMUL_CONTINUE; 2675 } 2676 2677 static int em_mov(struct x86_emulate_ctxt *ctxt) 2678 { 2679 struct decode_cache *c = &ctxt->decode; 2680 c->dst.val = c->src.val; 2681 return X86EMUL_CONTINUE; 2682 } 2683 2684 static int em_movdqu(struct x86_emulate_ctxt *ctxt) 2685 { 2686 struct decode_cache *c = &ctxt->decode; 2687 memcpy(&c->dst.vec_val, &c->src.vec_val, c->op_bytes); 2688 return X86EMUL_CONTINUE; 2689 } 2690 2691 static int em_invlpg(struct x86_emulate_ctxt *ctxt) 2692 { 2693 struct decode_cache *c = &ctxt->decode; 2694 int rc; 2695 ulong linear; 2696 2697 rc = linearize(ctxt, c->src.addr.mem, 1, false, &linear); 2698 if (rc == X86EMUL_CONTINUE) 2699 ctxt->ops->invlpg(ctxt, linear); 2700 /* Disable writeback. */ 2701 c->dst.type = OP_NONE; 2702 return X86EMUL_CONTINUE; 2703 } 2704 2705 static int em_clts(struct x86_emulate_ctxt *ctxt) 2706 { 2707 ulong cr0; 2708 2709 cr0 = ctxt->ops->get_cr(ctxt, 0); 2710 cr0 &= ~X86_CR0_TS; 2711 ctxt->ops->set_cr(ctxt, 0, cr0); 2712 return X86EMUL_CONTINUE; 2713 } 2714 2715 static int em_vmcall(struct x86_emulate_ctxt *ctxt) 2716 { 2717 struct decode_cache *c = &ctxt->decode; 2718 int rc; 2719 2720 if (c->modrm_mod != 3 || c->modrm_rm != 1) 2721 return X86EMUL_UNHANDLEABLE; 2722 2723 rc = ctxt->ops->fix_hypercall(ctxt); 2724 if (rc != X86EMUL_CONTINUE) 2725 return rc; 2726 2727 /* Let the processor re-execute the fixed hypercall */ 2728 c->eip = ctxt->eip; 2729 /* Disable writeback. */ 2730 c->dst.type = OP_NONE; 2731 return X86EMUL_CONTINUE; 2732 } 2733 2734 static int em_lgdt(struct x86_emulate_ctxt *ctxt) 2735 { 2736 struct decode_cache *c = &ctxt->decode; 2737 struct desc_ptr desc_ptr; 2738 int rc; 2739 2740 rc = read_descriptor(ctxt, c->src.addr.mem, 2741 &desc_ptr.size, &desc_ptr.address, 2742 c->op_bytes); 2743 if (rc != X86EMUL_CONTINUE) 2744 return rc; 2745 ctxt->ops->set_gdt(ctxt, &desc_ptr); 2746 /* Disable writeback. */ 2747 c->dst.type = OP_NONE; 2748 return X86EMUL_CONTINUE; 2749 } 2750 2751 static int em_vmmcall(struct x86_emulate_ctxt *ctxt) 2752 { 2753 struct decode_cache *c = &ctxt->decode; 2754 int rc; 2755 2756 rc = ctxt->ops->fix_hypercall(ctxt); 2757 2758 /* Disable writeback. */ 2759 c->dst.type = OP_NONE; 2760 return rc; 2761 } 2762 2763 static int em_lidt(struct x86_emulate_ctxt *ctxt) 2764 { 2765 struct decode_cache *c = &ctxt->decode; 2766 struct desc_ptr desc_ptr; 2767 int rc; 2768 2769 rc = read_descriptor(ctxt, c->src.addr.mem, 2770 &desc_ptr.size, &desc_ptr.address, 2771 c->op_bytes); 2772 if (rc != X86EMUL_CONTINUE) 2773 return rc; 2774 ctxt->ops->set_idt(ctxt, &desc_ptr); 2775 /* Disable writeback. */ 2776 c->dst.type = OP_NONE; 2777 return X86EMUL_CONTINUE; 2778 } 2779 2780 static int em_smsw(struct x86_emulate_ctxt *ctxt) 2781 { 2782 struct decode_cache *c = &ctxt->decode; 2783 2784 c->dst.bytes = 2; 2785 c->dst.val = ctxt->ops->get_cr(ctxt, 0); 2786 return X86EMUL_CONTINUE; 2787 } 2788 2789 static int em_lmsw(struct x86_emulate_ctxt *ctxt) 2790 { 2791 struct decode_cache *c = &ctxt->decode; 2792 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul) 2793 | (c->src.val & 0x0f)); 2794 c->dst.type = OP_NONE; 2795 return X86EMUL_CONTINUE; 2796 } 2797 2798 static bool valid_cr(int nr) 2799 { 2800 switch (nr) { 2801 case 0: 2802 case 2 ... 4: 2803 case 8: 2804 return true; 2805 default: 2806 return false; 2807 } 2808 } 2809 2810 static int check_cr_read(struct x86_emulate_ctxt *ctxt) 2811 { 2812 struct decode_cache *c = &ctxt->decode; 2813 2814 if (!valid_cr(c->modrm_reg)) 2815 return emulate_ud(ctxt); 2816 2817 return X86EMUL_CONTINUE; 2818 } 2819 2820 static int check_cr_write(struct x86_emulate_ctxt *ctxt) 2821 { 2822 struct decode_cache *c = &ctxt->decode; 2823 u64 new_val = c->src.val64; 2824 int cr = c->modrm_reg; 2825 u64 efer = 0; 2826 2827 static u64 cr_reserved_bits[] = { 2828 0xffffffff00000000ULL, 2829 0, 0, 0, /* CR3 checked later */ 2830 CR4_RESERVED_BITS, 2831 0, 0, 0, 2832 CR8_RESERVED_BITS, 2833 }; 2834 2835 if (!valid_cr(cr)) 2836 return emulate_ud(ctxt); 2837 2838 if (new_val & cr_reserved_bits[cr]) 2839 return emulate_gp(ctxt, 0); 2840 2841 switch (cr) { 2842 case 0: { 2843 u64 cr4; 2844 if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) || 2845 ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD))) 2846 return emulate_gp(ctxt, 0); 2847 2848 cr4 = ctxt->ops->get_cr(ctxt, 4); 2849 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 2850 2851 if ((new_val & X86_CR0_PG) && (efer & EFER_LME) && 2852 !(cr4 & X86_CR4_PAE)) 2853 return emulate_gp(ctxt, 0); 2854 2855 break; 2856 } 2857 case 3: { 2858 u64 rsvd = 0; 2859 2860 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 2861 if (efer & EFER_LMA) 2862 rsvd = CR3_L_MODE_RESERVED_BITS; 2863 else if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PAE) 2864 rsvd = CR3_PAE_RESERVED_BITS; 2865 else if (ctxt->ops->get_cr(ctxt, 0) & X86_CR0_PG) 2866 rsvd = CR3_NONPAE_RESERVED_BITS; 2867 2868 if (new_val & rsvd) 2869 return emulate_gp(ctxt, 0); 2870 2871 break; 2872 } 2873 case 4: { 2874 u64 cr4; 2875 2876 cr4 = ctxt->ops->get_cr(ctxt, 4); 2877 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 2878 2879 if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE)) 2880 return emulate_gp(ctxt, 0); 2881 2882 break; 2883 } 2884 } 2885 2886 return X86EMUL_CONTINUE; 2887 } 2888 2889 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt) 2890 { 2891 unsigned long dr7; 2892 2893 ctxt->ops->get_dr(ctxt, 7, &dr7); 2894 2895 /* Check if DR7.Global_Enable is set */ 2896 return dr7 & (1 << 13); 2897 } 2898 2899 static int check_dr_read(struct x86_emulate_ctxt *ctxt) 2900 { 2901 struct decode_cache *c = &ctxt->decode; 2902 int dr = c->modrm_reg; 2903 u64 cr4; 2904 2905 if (dr > 7) 2906 return emulate_ud(ctxt); 2907 2908 cr4 = ctxt->ops->get_cr(ctxt, 4); 2909 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5)) 2910 return emulate_ud(ctxt); 2911 2912 if (check_dr7_gd(ctxt)) 2913 return emulate_db(ctxt); 2914 2915 return X86EMUL_CONTINUE; 2916 } 2917 2918 static int check_dr_write(struct x86_emulate_ctxt *ctxt) 2919 { 2920 struct decode_cache *c = &ctxt->decode; 2921 u64 new_val = c->src.val64; 2922 int dr = c->modrm_reg; 2923 2924 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL)) 2925 return emulate_gp(ctxt, 0); 2926 2927 return check_dr_read(ctxt); 2928 } 2929 2930 static int check_svme(struct x86_emulate_ctxt *ctxt) 2931 { 2932 u64 efer; 2933 2934 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer); 2935 2936 if (!(efer & EFER_SVME)) 2937 return emulate_ud(ctxt); 2938 2939 return X86EMUL_CONTINUE; 2940 } 2941 2942 static int check_svme_pa(struct x86_emulate_ctxt *ctxt) 2943 { 2944 u64 rax = ctxt->decode.regs[VCPU_REGS_RAX]; 2945 2946 /* Valid physical address? */ 2947 if (rax & 0xffff000000000000ULL) 2948 return emulate_gp(ctxt, 0); 2949 2950 return check_svme(ctxt); 2951 } 2952 2953 static int check_rdtsc(struct x86_emulate_ctxt *ctxt) 2954 { 2955 u64 cr4 = ctxt->ops->get_cr(ctxt, 4); 2956 2957 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt)) 2958 return emulate_ud(ctxt); 2959 2960 return X86EMUL_CONTINUE; 2961 } 2962 2963 static int check_rdpmc(struct x86_emulate_ctxt *ctxt) 2964 { 2965 u64 cr4 = ctxt->ops->get_cr(ctxt, 4); 2966 u64 rcx = ctxt->decode.regs[VCPU_REGS_RCX]; 2967 2968 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) || 2969 (rcx > 3)) 2970 return emulate_gp(ctxt, 0); 2971 2972 return X86EMUL_CONTINUE; 2973 } 2974 2975 static int check_perm_in(struct x86_emulate_ctxt *ctxt) 2976 { 2977 struct decode_cache *c = &ctxt->decode; 2978 2979 c->dst.bytes = min(c->dst.bytes, 4u); 2980 if (!emulator_io_permited(ctxt, ctxt->ops, c->src.val, c->dst.bytes)) 2981 return emulate_gp(ctxt, 0); 2982 2983 return X86EMUL_CONTINUE; 2984 } 2985 2986 static int check_perm_out(struct x86_emulate_ctxt *ctxt) 2987 { 2988 struct decode_cache *c = &ctxt->decode; 2989 2990 c->src.bytes = min(c->src.bytes, 4u); 2991 if (!emulator_io_permited(ctxt, ctxt->ops, c->dst.val, c->src.bytes)) 2992 return emulate_gp(ctxt, 0); 2993 2994 return X86EMUL_CONTINUE; 2995 } 2996 2997 #define D(_y) { .flags = (_y) } 2998 #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i } 2999 #define DIP(_y, _i, _p) { .flags = (_y), .intercept = x86_intercept_##_i, \ 3000 .check_perm = (_p) } 3001 #define N D(0) 3002 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) } 3003 #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) } 3004 #define GD(_f, _g) { .flags = ((_f) | GroupDual), .u.gdual = (_g) } 3005 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) } 3006 #define II(_f, _e, _i) \ 3007 { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i } 3008 #define IIP(_f, _e, _i, _p) \ 3009 { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i, \ 3010 .check_perm = (_p) } 3011 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) } 3012 3013 #define D2bv(_f) D((_f) | ByteOp), D(_f) 3014 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p) 3015 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e) 3016 3017 #define I6ALU(_f, _e) I2bv((_f) | DstMem | SrcReg | ModRM, _e), \ 3018 I2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \ 3019 I2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e) 3020 3021 static struct opcode group7_rm1[] = { 3022 DI(SrcNone | ModRM | Priv, monitor), 3023 DI(SrcNone | ModRM | Priv, mwait), 3024 N, N, N, N, N, N, 3025 }; 3026 3027 static struct opcode group7_rm3[] = { 3028 DIP(SrcNone | ModRM | Prot | Priv, vmrun, check_svme_pa), 3029 II(SrcNone | ModRM | Prot | VendorSpecific, em_vmmcall, vmmcall), 3030 DIP(SrcNone | ModRM | Prot | Priv, vmload, check_svme_pa), 3031 DIP(SrcNone | ModRM | Prot | Priv, vmsave, check_svme_pa), 3032 DIP(SrcNone | ModRM | Prot | Priv, stgi, check_svme), 3033 DIP(SrcNone | ModRM | Prot | Priv, clgi, check_svme), 3034 DIP(SrcNone | ModRM | Prot | Priv, skinit, check_svme), 3035 DIP(SrcNone | ModRM | Prot | Priv, invlpga, check_svme), 3036 }; 3037 3038 static struct opcode group7_rm7[] = { 3039 N, 3040 DIP(SrcNone | ModRM, rdtscp, check_rdtsc), 3041 N, N, N, N, N, N, 3042 }; 3043 3044 static struct opcode group1[] = { 3045 I(Lock, em_add), 3046 I(Lock, em_or), 3047 I(Lock, em_adc), 3048 I(Lock, em_sbb), 3049 I(Lock, em_and), 3050 I(Lock, em_sub), 3051 I(Lock, em_xor), 3052 I(0, em_cmp), 3053 }; 3054 3055 static struct opcode group1A[] = { 3056 D(DstMem | SrcNone | ModRM | Mov | Stack), N, N, N, N, N, N, N, 3057 }; 3058 3059 static struct opcode group3[] = { 3060 D(DstMem | SrcImm | ModRM), D(DstMem | SrcImm | ModRM), 3061 D(DstMem | SrcNone | ModRM | Lock), D(DstMem | SrcNone | ModRM | Lock), 3062 X4(D(SrcMem | ModRM)), 3063 }; 3064 3065 static struct opcode group4[] = { 3066 D(ByteOp | DstMem | SrcNone | ModRM | Lock), D(ByteOp | DstMem | SrcNone | ModRM | Lock), 3067 N, N, N, N, N, N, 3068 }; 3069 3070 static struct opcode group5[] = { 3071 D(DstMem | SrcNone | ModRM | Lock), D(DstMem | SrcNone | ModRM | Lock), 3072 D(SrcMem | ModRM | Stack), 3073 I(SrcMemFAddr | ModRM | ImplicitOps | Stack, em_call_far), 3074 D(SrcMem | ModRM | Stack), D(SrcMemFAddr | ModRM | ImplicitOps), 3075 D(SrcMem | ModRM | Stack), N, 3076 }; 3077 3078 static struct opcode group6[] = { 3079 DI(ModRM | Prot, sldt), 3080 DI(ModRM | Prot, str), 3081 DI(ModRM | Prot | Priv, lldt), 3082 DI(ModRM | Prot | Priv, ltr), 3083 N, N, N, N, 3084 }; 3085 3086 static struct group_dual group7 = { { 3087 DI(ModRM | Mov | DstMem | Priv, sgdt), 3088 DI(ModRM | Mov | DstMem | Priv, sidt), 3089 II(ModRM | SrcMem | Priv, em_lgdt, lgdt), 3090 II(ModRM | SrcMem | Priv, em_lidt, lidt), 3091 II(SrcNone | ModRM | DstMem | Mov, em_smsw, smsw), N, 3092 II(SrcMem16 | ModRM | Mov | Priv, em_lmsw, lmsw), 3093 II(SrcMem | ModRM | ByteOp | Priv | NoAccess, em_invlpg, invlpg), 3094 }, { 3095 I(SrcNone | ModRM | Priv | VendorSpecific, em_vmcall), 3096 EXT(0, group7_rm1), 3097 N, EXT(0, group7_rm3), 3098 II(SrcNone | ModRM | DstMem | Mov, em_smsw, smsw), N, 3099 II(SrcMem16 | ModRM | Mov | Priv, em_lmsw, lmsw), EXT(0, group7_rm7), 3100 } }; 3101 3102 static struct opcode group8[] = { 3103 N, N, N, N, 3104 D(DstMem | SrcImmByte | ModRM), D(DstMem | SrcImmByte | ModRM | Lock), 3105 D(DstMem | SrcImmByte | ModRM | Lock), D(DstMem | SrcImmByte | ModRM | Lock), 3106 }; 3107 3108 static struct group_dual group9 = { { 3109 N, D(DstMem64 | ModRM | Lock), N, N, N, N, N, N, 3110 }, { 3111 N, N, N, N, N, N, N, N, 3112 } }; 3113 3114 static struct opcode group11[] = { 3115 I(DstMem | SrcImm | ModRM | Mov, em_mov), X7(D(Undefined)), 3116 }; 3117 3118 static struct gprefix pfx_0f_6f_0f_7f = { 3119 N, N, N, I(Sse, em_movdqu), 3120 }; 3121 3122 static struct opcode opcode_table[256] = { 3123 /* 0x00 - 0x07 */ 3124 I6ALU(Lock, em_add), 3125 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64), 3126 /* 0x08 - 0x0F */ 3127 I6ALU(Lock, em_or), 3128 D(ImplicitOps | Stack | No64), N, 3129 /* 0x10 - 0x17 */ 3130 I6ALU(Lock, em_adc), 3131 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64), 3132 /* 0x18 - 0x1F */ 3133 I6ALU(Lock, em_sbb), 3134 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64), 3135 /* 0x20 - 0x27 */ 3136 I6ALU(Lock, em_and), N, N, 3137 /* 0x28 - 0x2F */ 3138 I6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das), 3139 /* 0x30 - 0x37 */ 3140 I6ALU(Lock, em_xor), N, N, 3141 /* 0x38 - 0x3F */ 3142 I6ALU(0, em_cmp), N, N, 3143 /* 0x40 - 0x4F */ 3144 X16(D(DstReg)), 3145 /* 0x50 - 0x57 */ 3146 X8(I(SrcReg | Stack, em_push)), 3147 /* 0x58 - 0x5F */ 3148 X8(I(DstReg | Stack, em_pop)), 3149 /* 0x60 - 0x67 */ 3150 I(ImplicitOps | Stack | No64, em_pusha), 3151 I(ImplicitOps | Stack | No64, em_popa), 3152 N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ , 3153 N, N, N, N, 3154 /* 0x68 - 0x6F */ 3155 I(SrcImm | Mov | Stack, em_push), 3156 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op), 3157 I(SrcImmByte | Mov | Stack, em_push), 3158 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op), 3159 D2bvIP(DstDI | SrcDX | Mov | String, ins, check_perm_in), /* insb, insw/insd */ 3160 D2bvIP(SrcSI | DstDX | String, outs, check_perm_out), /* outsb, outsw/outsd */ 3161 /* 0x70 - 0x7F */ 3162 X16(D(SrcImmByte)), 3163 /* 0x80 - 0x87 */ 3164 G(ByteOp | DstMem | SrcImm | ModRM | Group, group1), 3165 G(DstMem | SrcImm | ModRM | Group, group1), 3166 G(ByteOp | DstMem | SrcImm | ModRM | No64 | Group, group1), 3167 G(DstMem | SrcImmByte | ModRM | Group, group1), 3168 D2bv(DstMem | SrcReg | ModRM), D2bv(DstMem | SrcReg | ModRM | Lock), 3169 /* 0x88 - 0x8F */ 3170 I2bv(DstMem | SrcReg | ModRM | Mov, em_mov), 3171 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov), 3172 D(DstMem | SrcNone | ModRM | Mov), D(ModRM | SrcMem | NoAccess | DstReg), 3173 D(ImplicitOps | SrcMem16 | ModRM), G(0, group1A), 3174 /* 0x90 - 0x97 */ 3175 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)), 3176 /* 0x98 - 0x9F */ 3177 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd), 3178 I(SrcImmFAddr | No64, em_call_far), N, 3179 II(ImplicitOps | Stack, em_pushf, pushf), 3180 II(ImplicitOps | Stack, em_popf, popf), N, N, 3181 /* 0xA0 - 0xA7 */ 3182 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov), 3183 I2bv(DstMem | SrcAcc | Mov | MemAbs, em_mov), 3184 I2bv(SrcSI | DstDI | Mov | String, em_mov), 3185 I2bv(SrcSI | DstDI | String, em_cmp), 3186 /* 0xA8 - 0xAF */ 3187 D2bv(DstAcc | SrcImm), 3188 I2bv(SrcAcc | DstDI | Mov | String, em_mov), 3189 I2bv(SrcSI | DstAcc | Mov | String, em_mov), 3190 I2bv(SrcAcc | DstDI | String, em_cmp), 3191 /* 0xB0 - 0xB7 */ 3192 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)), 3193 /* 0xB8 - 0xBF */ 3194 X8(I(DstReg | SrcImm | Mov, em_mov)), 3195 /* 0xC0 - 0xC7 */ 3196 D2bv(DstMem | SrcImmByte | ModRM), 3197 I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm), 3198 D(ImplicitOps | Stack), 3199 D(DstReg | SrcMemFAddr | ModRM | No64), D(DstReg | SrcMemFAddr | ModRM | No64), 3200 G(ByteOp, group11), G(0, group11), 3201 /* 0xC8 - 0xCF */ 3202 N, N, N, D(ImplicitOps | Stack), 3203 D(ImplicitOps), DI(SrcImmByte, intn), 3204 D(ImplicitOps | No64), DI(ImplicitOps, iret), 3205 /* 0xD0 - 0xD7 */ 3206 D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM), 3207 N, N, N, N, 3208 /* 0xD8 - 0xDF */ 3209 N, N, N, N, N, N, N, N, 3210 /* 0xE0 - 0xE7 */ 3211 X4(D(SrcImmByte)), 3212 D2bvIP(SrcImmUByte | DstAcc, in, check_perm_in), 3213 D2bvIP(SrcAcc | DstImmUByte, out, check_perm_out), 3214 /* 0xE8 - 0xEF */ 3215 D(SrcImm | Stack), D(SrcImm | ImplicitOps), 3216 D(SrcImmFAddr | No64), D(SrcImmByte | ImplicitOps), 3217 D2bvIP(SrcDX | DstAcc, in, check_perm_in), 3218 D2bvIP(SrcAcc | DstDX, out, check_perm_out), 3219 /* 0xF0 - 0xF7 */ 3220 N, DI(ImplicitOps, icebp), N, N, 3221 DI(ImplicitOps | Priv, hlt), D(ImplicitOps), 3222 G(ByteOp, group3), G(0, group3), 3223 /* 0xF8 - 0xFF */ 3224 D(ImplicitOps), D(ImplicitOps), D(ImplicitOps), D(ImplicitOps), 3225 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5), 3226 }; 3227 3228 static struct opcode twobyte_table[256] = { 3229 /* 0x00 - 0x0F */ 3230 G(0, group6), GD(0, &group7), N, N, 3231 N, D(ImplicitOps | VendorSpecific), DI(ImplicitOps | Priv, clts), N, 3232 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N, 3233 N, D(ImplicitOps | ModRM), N, N, 3234 /* 0x10 - 0x1F */ 3235 N, N, N, N, N, N, N, N, D(ImplicitOps | ModRM), N, N, N, N, N, N, N, 3236 /* 0x20 - 0x2F */ 3237 DIP(ModRM | DstMem | Priv | Op3264, cr_read, check_cr_read), 3238 DIP(ModRM | DstMem | Priv | Op3264, dr_read, check_dr_read), 3239 DIP(ModRM | SrcMem | Priv | Op3264, cr_write, check_cr_write), 3240 DIP(ModRM | SrcMem | Priv | Op3264, dr_write, check_dr_write), 3241 N, N, N, N, 3242 N, N, N, N, N, N, N, N, 3243 /* 0x30 - 0x3F */ 3244 DI(ImplicitOps | Priv, wrmsr), 3245 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc), 3246 DI(ImplicitOps | Priv, rdmsr), 3247 DIP(ImplicitOps | Priv, rdpmc, check_rdpmc), 3248 D(ImplicitOps | VendorSpecific), D(ImplicitOps | Priv | VendorSpecific), 3249 N, N, 3250 N, N, N, N, N, N, N, N, 3251 /* 0x40 - 0x4F */ 3252 X16(D(DstReg | SrcMem | ModRM | Mov)), 3253 /* 0x50 - 0x5F */ 3254 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 3255 /* 0x60 - 0x6F */ 3256 N, N, N, N, 3257 N, N, N, N, 3258 N, N, N, N, 3259 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f), 3260 /* 0x70 - 0x7F */ 3261 N, N, N, N, 3262 N, N, N, N, 3263 N, N, N, N, 3264 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f), 3265 /* 0x80 - 0x8F */ 3266 X16(D(SrcImm)), 3267 /* 0x90 - 0x9F */ 3268 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)), 3269 /* 0xA0 - 0xA7 */ 3270 D(ImplicitOps | Stack), D(ImplicitOps | Stack), 3271 DI(ImplicitOps, cpuid), D(DstMem | SrcReg | ModRM | BitOp), 3272 D(DstMem | SrcReg | Src2ImmByte | ModRM), 3273 D(DstMem | SrcReg | Src2CL | ModRM), N, N, 3274 /* 0xA8 - 0xAF */ 3275 D(ImplicitOps | Stack), D(ImplicitOps | Stack), 3276 DI(ImplicitOps, rsm), D(DstMem | SrcReg | ModRM | BitOp | Lock), 3277 D(DstMem | SrcReg | Src2ImmByte | ModRM), 3278 D(DstMem | SrcReg | Src2CL | ModRM), 3279 D(ModRM), I(DstReg | SrcMem | ModRM, em_imul), 3280 /* 0xB0 - 0xB7 */ 3281 D2bv(DstMem | SrcReg | ModRM | Lock), 3282 D(DstReg | SrcMemFAddr | ModRM), D(DstMem | SrcReg | ModRM | BitOp | Lock), 3283 D(DstReg | SrcMemFAddr | ModRM), D(DstReg | SrcMemFAddr | ModRM), 3284 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), 3285 /* 0xB8 - 0xBF */ 3286 N, N, 3287 G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock), 3288 D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM), 3289 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov), 3290 /* 0xC0 - 0xCF */ 3291 D2bv(DstMem | SrcReg | ModRM | Lock), 3292 N, D(DstMem | SrcReg | ModRM | Mov), 3293 N, N, N, GD(0, &group9), 3294 N, N, N, N, N, N, N, N, 3295 /* 0xD0 - 0xDF */ 3296 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 3297 /* 0xE0 - 0xEF */ 3298 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, 3299 /* 0xF0 - 0xFF */ 3300 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N 3301 }; 3302 3303 #undef D 3304 #undef N 3305 #undef G 3306 #undef GD 3307 #undef I 3308 #undef GP 3309 #undef EXT 3310 3311 #undef D2bv 3312 #undef D2bvIP 3313 #undef I2bv 3314 #undef I6ALU 3315 3316 static unsigned imm_size(struct decode_cache *c) 3317 { 3318 unsigned size; 3319 3320 size = (c->d & ByteOp) ? 1 : c->op_bytes; 3321 if (size == 8) 3322 size = 4; 3323 return size; 3324 } 3325 3326 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op, 3327 unsigned size, bool sign_extension) 3328 { 3329 struct decode_cache *c = &ctxt->decode; 3330 struct x86_emulate_ops *ops = ctxt->ops; 3331 int rc = X86EMUL_CONTINUE; 3332 3333 op->type = OP_IMM; 3334 op->bytes = size; 3335 op->addr.mem.ea = c->eip; 3336 /* NB. Immediates are sign-extended as necessary. */ 3337 switch (op->bytes) { 3338 case 1: 3339 op->val = insn_fetch(s8, 1, c->eip); 3340 break; 3341 case 2: 3342 op->val = insn_fetch(s16, 2, c->eip); 3343 break; 3344 case 4: 3345 op->val = insn_fetch(s32, 4, c->eip); 3346 break; 3347 } 3348 if (!sign_extension) { 3349 switch (op->bytes) { 3350 case 1: 3351 op->val &= 0xff; 3352 break; 3353 case 2: 3354 op->val &= 0xffff; 3355 break; 3356 case 4: 3357 op->val &= 0xffffffff; 3358 break; 3359 } 3360 } 3361 done: 3362 return rc; 3363 } 3364 3365 int 3366 x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len) 3367 { 3368 struct x86_emulate_ops *ops = ctxt->ops; 3369 struct decode_cache *c = &ctxt->decode; 3370 int rc = X86EMUL_CONTINUE; 3371 int mode = ctxt->mode; 3372 int def_op_bytes, def_ad_bytes, goffset, simd_prefix; 3373 bool op_prefix = false; 3374 struct opcode opcode; 3375 struct operand memop = { .type = OP_NONE }; 3376 3377 c->eip = ctxt->eip; 3378 c->fetch.start = c->eip; 3379 c->fetch.end = c->fetch.start + insn_len; 3380 if (insn_len > 0) 3381 memcpy(c->fetch.data, insn, insn_len); 3382 3383 switch (mode) { 3384 case X86EMUL_MODE_REAL: 3385 case X86EMUL_MODE_VM86: 3386 case X86EMUL_MODE_PROT16: 3387 def_op_bytes = def_ad_bytes = 2; 3388 break; 3389 case X86EMUL_MODE_PROT32: 3390 def_op_bytes = def_ad_bytes = 4; 3391 break; 3392 #ifdef CONFIG_X86_64 3393 case X86EMUL_MODE_PROT64: 3394 def_op_bytes = 4; 3395 def_ad_bytes = 8; 3396 break; 3397 #endif 3398 default: 3399 return -1; 3400 } 3401 3402 c->op_bytes = def_op_bytes; 3403 c->ad_bytes = def_ad_bytes; 3404 3405 /* Legacy prefixes. */ 3406 for (;;) { 3407 switch (c->b = insn_fetch(u8, 1, c->eip)) { 3408 case 0x66: /* operand-size override */ 3409 op_prefix = true; 3410 /* switch between 2/4 bytes */ 3411 c->op_bytes = def_op_bytes ^ 6; 3412 break; 3413 case 0x67: /* address-size override */ 3414 if (mode == X86EMUL_MODE_PROT64) 3415 /* switch between 4/8 bytes */ 3416 c->ad_bytes = def_ad_bytes ^ 12; 3417 else 3418 /* switch between 2/4 bytes */ 3419 c->ad_bytes = def_ad_bytes ^ 6; 3420 break; 3421 case 0x26: /* ES override */ 3422 case 0x2e: /* CS override */ 3423 case 0x36: /* SS override */ 3424 case 0x3e: /* DS override */ 3425 set_seg_override(c, (c->b >> 3) & 3); 3426 break; 3427 case 0x64: /* FS override */ 3428 case 0x65: /* GS override */ 3429 set_seg_override(c, c->b & 7); 3430 break; 3431 case 0x40 ... 0x4f: /* REX */ 3432 if (mode != X86EMUL_MODE_PROT64) 3433 goto done_prefixes; 3434 c->rex_prefix = c->b; 3435 continue; 3436 case 0xf0: /* LOCK */ 3437 c->lock_prefix = 1; 3438 break; 3439 case 0xf2: /* REPNE/REPNZ */ 3440 case 0xf3: /* REP/REPE/REPZ */ 3441 c->rep_prefix = c->b; 3442 break; 3443 default: 3444 goto done_prefixes; 3445 } 3446 3447 /* Any legacy prefix after a REX prefix nullifies its effect. */ 3448 3449 c->rex_prefix = 0; 3450 } 3451 3452 done_prefixes: 3453 3454 /* REX prefix. */ 3455 if (c->rex_prefix & 8) 3456 c->op_bytes = 8; /* REX.W */ 3457 3458 /* Opcode byte(s). */ 3459 opcode = opcode_table[c->b]; 3460 /* Two-byte opcode? */ 3461 if (c->b == 0x0f) { 3462 c->twobyte = 1; 3463 c->b = insn_fetch(u8, 1, c->eip); 3464 opcode = twobyte_table[c->b]; 3465 } 3466 c->d = opcode.flags; 3467 3468 while (c->d & GroupMask) { 3469 switch (c->d & GroupMask) { 3470 case Group: 3471 c->modrm = insn_fetch(u8, 1, c->eip); 3472 --c->eip; 3473 goffset = (c->modrm >> 3) & 7; 3474 opcode = opcode.u.group[goffset]; 3475 break; 3476 case GroupDual: 3477 c->modrm = insn_fetch(u8, 1, c->eip); 3478 --c->eip; 3479 goffset = (c->modrm >> 3) & 7; 3480 if ((c->modrm >> 6) == 3) 3481 opcode = opcode.u.gdual->mod3[goffset]; 3482 else 3483 opcode = opcode.u.gdual->mod012[goffset]; 3484 break; 3485 case RMExt: 3486 goffset = c->modrm & 7; 3487 opcode = opcode.u.group[goffset]; 3488 break; 3489 case Prefix: 3490 if (c->rep_prefix && op_prefix) 3491 return X86EMUL_UNHANDLEABLE; 3492 simd_prefix = op_prefix ? 0x66 : c->rep_prefix; 3493 switch (simd_prefix) { 3494 case 0x00: opcode = opcode.u.gprefix->pfx_no; break; 3495 case 0x66: opcode = opcode.u.gprefix->pfx_66; break; 3496 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break; 3497 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break; 3498 } 3499 break; 3500 default: 3501 return X86EMUL_UNHANDLEABLE; 3502 } 3503 3504 c->d &= ~GroupMask; 3505 c->d |= opcode.flags; 3506 } 3507 3508 c->execute = opcode.u.execute; 3509 c->check_perm = opcode.check_perm; 3510 c->intercept = opcode.intercept; 3511 3512 /* Unrecognised? */ 3513 if (c->d == 0 || (c->d & Undefined)) 3514 return -1; 3515 3516 if (!(c->d & VendorSpecific) && ctxt->only_vendor_specific_insn) 3517 return -1; 3518 3519 if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack)) 3520 c->op_bytes = 8; 3521 3522 if (c->d & Op3264) { 3523 if (mode == X86EMUL_MODE_PROT64) 3524 c->op_bytes = 8; 3525 else 3526 c->op_bytes = 4; 3527 } 3528 3529 if (c->d & Sse) 3530 c->op_bytes = 16; 3531 3532 /* ModRM and SIB bytes. */ 3533 if (c->d & ModRM) { 3534 rc = decode_modrm(ctxt, ops, &memop); 3535 if (!c->has_seg_override) 3536 set_seg_override(c, c->modrm_seg); 3537 } else if (c->d & MemAbs) 3538 rc = decode_abs(ctxt, ops, &memop); 3539 if (rc != X86EMUL_CONTINUE) 3540 goto done; 3541 3542 if (!c->has_seg_override) 3543 set_seg_override(c, VCPU_SREG_DS); 3544 3545 memop.addr.mem.seg = seg_override(ctxt, c); 3546 3547 if (memop.type == OP_MEM && c->ad_bytes != 8) 3548 memop.addr.mem.ea = (u32)memop.addr.mem.ea; 3549 3550 if (memop.type == OP_MEM && c->rip_relative) 3551 memop.addr.mem.ea += c->eip; 3552 3553 /* 3554 * Decode and fetch the source operand: register, memory 3555 * or immediate. 3556 */ 3557 switch (c->d & SrcMask) { 3558 case SrcNone: 3559 break; 3560 case SrcReg: 3561 decode_register_operand(ctxt, &c->src, c, 0); 3562 break; 3563 case SrcMem16: 3564 memop.bytes = 2; 3565 goto srcmem_common; 3566 case SrcMem32: 3567 memop.bytes = 4; 3568 goto srcmem_common; 3569 case SrcMem: 3570 memop.bytes = (c->d & ByteOp) ? 1 : 3571 c->op_bytes; 3572 srcmem_common: 3573 c->src = memop; 3574 break; 3575 case SrcImmU16: 3576 rc = decode_imm(ctxt, &c->src, 2, false); 3577 break; 3578 case SrcImm: 3579 rc = decode_imm(ctxt, &c->src, imm_size(c), true); 3580 break; 3581 case SrcImmU: 3582 rc = decode_imm(ctxt, &c->src, imm_size(c), false); 3583 break; 3584 case SrcImmByte: 3585 rc = decode_imm(ctxt, &c->src, 1, true); 3586 break; 3587 case SrcImmUByte: 3588 rc = decode_imm(ctxt, &c->src, 1, false); 3589 break; 3590 case SrcAcc: 3591 c->src.type = OP_REG; 3592 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 3593 c->src.addr.reg = &c->regs[VCPU_REGS_RAX]; 3594 fetch_register_operand(&c->src); 3595 break; 3596 case SrcOne: 3597 c->src.bytes = 1; 3598 c->src.val = 1; 3599 break; 3600 case SrcSI: 3601 c->src.type = OP_MEM; 3602 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 3603 c->src.addr.mem.ea = 3604 register_address(c, c->regs[VCPU_REGS_RSI]); 3605 c->src.addr.mem.seg = seg_override(ctxt, c); 3606 c->src.val = 0; 3607 break; 3608 case SrcImmFAddr: 3609 c->src.type = OP_IMM; 3610 c->src.addr.mem.ea = c->eip; 3611 c->src.bytes = c->op_bytes + 2; 3612 insn_fetch_arr(c->src.valptr, c->src.bytes, c->eip); 3613 break; 3614 case SrcMemFAddr: 3615 memop.bytes = c->op_bytes + 2; 3616 goto srcmem_common; 3617 break; 3618 case SrcDX: 3619 c->src.type = OP_REG; 3620 c->src.bytes = 2; 3621 c->src.addr.reg = &c->regs[VCPU_REGS_RDX]; 3622 fetch_register_operand(&c->src); 3623 break; 3624 } 3625 3626 if (rc != X86EMUL_CONTINUE) 3627 goto done; 3628 3629 /* 3630 * Decode and fetch the second source operand: register, memory 3631 * or immediate. 3632 */ 3633 switch (c->d & Src2Mask) { 3634 case Src2None: 3635 break; 3636 case Src2CL: 3637 c->src2.bytes = 1; 3638 c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8; 3639 break; 3640 case Src2ImmByte: 3641 rc = decode_imm(ctxt, &c->src2, 1, true); 3642 break; 3643 case Src2One: 3644 c->src2.bytes = 1; 3645 c->src2.val = 1; 3646 break; 3647 case Src2Imm: 3648 rc = decode_imm(ctxt, &c->src2, imm_size(c), true); 3649 break; 3650 } 3651 3652 if (rc != X86EMUL_CONTINUE) 3653 goto done; 3654 3655 /* Decode and fetch the destination operand: register or memory. */ 3656 switch (c->d & DstMask) { 3657 case DstReg: 3658 decode_register_operand(ctxt, &c->dst, c, 3659 c->twobyte && (c->b == 0xb6 || c->b == 0xb7)); 3660 break; 3661 case DstImmUByte: 3662 c->dst.type = OP_IMM; 3663 c->dst.addr.mem.ea = c->eip; 3664 c->dst.bytes = 1; 3665 c->dst.val = insn_fetch(u8, 1, c->eip); 3666 break; 3667 case DstMem: 3668 case DstMem64: 3669 c->dst = memop; 3670 if ((c->d & DstMask) == DstMem64) 3671 c->dst.bytes = 8; 3672 else 3673 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 3674 if (c->d & BitOp) 3675 fetch_bit_operand(c); 3676 c->dst.orig_val = c->dst.val; 3677 break; 3678 case DstAcc: 3679 c->dst.type = OP_REG; 3680 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 3681 c->dst.addr.reg = &c->regs[VCPU_REGS_RAX]; 3682 fetch_register_operand(&c->dst); 3683 c->dst.orig_val = c->dst.val; 3684 break; 3685 case DstDI: 3686 c->dst.type = OP_MEM; 3687 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes; 3688 c->dst.addr.mem.ea = 3689 register_address(c, c->regs[VCPU_REGS_RDI]); 3690 c->dst.addr.mem.seg = VCPU_SREG_ES; 3691 c->dst.val = 0; 3692 break; 3693 case DstDX: 3694 c->dst.type = OP_REG; 3695 c->dst.bytes = 2; 3696 c->dst.addr.reg = &c->regs[VCPU_REGS_RDX]; 3697 fetch_register_operand(&c->dst); 3698 break; 3699 case ImplicitOps: 3700 /* Special instructions do their own operand decoding. */ 3701 default: 3702 c->dst.type = OP_NONE; /* Disable writeback. */ 3703 return 0; 3704 } 3705 3706 done: 3707 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 3708 } 3709 3710 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt) 3711 { 3712 struct decode_cache *c = &ctxt->decode; 3713 3714 /* The second termination condition only applies for REPE 3715 * and REPNE. Test if the repeat string operation prefix is 3716 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the 3717 * corresponding termination condition according to: 3718 * - if REPE/REPZ and ZF = 0 then done 3719 * - if REPNE/REPNZ and ZF = 1 then done 3720 */ 3721 if (((c->b == 0xa6) || (c->b == 0xa7) || 3722 (c->b == 0xae) || (c->b == 0xaf)) 3723 && (((c->rep_prefix == REPE_PREFIX) && 3724 ((ctxt->eflags & EFLG_ZF) == 0)) 3725 || ((c->rep_prefix == REPNE_PREFIX) && 3726 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF)))) 3727 return true; 3728 3729 return false; 3730 } 3731 3732 int 3733 x86_emulate_insn(struct x86_emulate_ctxt *ctxt) 3734 { 3735 struct x86_emulate_ops *ops = ctxt->ops; 3736 u64 msr_data; 3737 struct decode_cache *c = &ctxt->decode; 3738 int rc = X86EMUL_CONTINUE; 3739 int saved_dst_type = c->dst.type; 3740 int irq; /* Used for int 3, int, and into */ 3741 3742 ctxt->decode.mem_read.pos = 0; 3743 3744 if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) { 3745 rc = emulate_ud(ctxt); 3746 goto done; 3747 } 3748 3749 /* LOCK prefix is allowed only with some instructions */ 3750 if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) { 3751 rc = emulate_ud(ctxt); 3752 goto done; 3753 } 3754 3755 if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) { 3756 rc = emulate_ud(ctxt); 3757 goto done; 3758 } 3759 3760 if ((c->d & Sse) 3761 && ((ops->get_cr(ctxt, 0) & X86_CR0_EM) 3762 || !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) { 3763 rc = emulate_ud(ctxt); 3764 goto done; 3765 } 3766 3767 if ((c->d & Sse) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) { 3768 rc = emulate_nm(ctxt); 3769 goto done; 3770 } 3771 3772 if (unlikely(ctxt->guest_mode) && c->intercept) { 3773 rc = emulator_check_intercept(ctxt, c->intercept, 3774 X86_ICPT_PRE_EXCEPT); 3775 if (rc != X86EMUL_CONTINUE) 3776 goto done; 3777 } 3778 3779 /* Privileged instruction can be executed only in CPL=0 */ 3780 if ((c->d & Priv) && ops->cpl(ctxt)) { 3781 rc = emulate_gp(ctxt, 0); 3782 goto done; 3783 } 3784 3785 /* Instruction can only be executed in protected mode */ 3786 if ((c->d & Prot) && !(ctxt->mode & X86EMUL_MODE_PROT)) { 3787 rc = emulate_ud(ctxt); 3788 goto done; 3789 } 3790 3791 /* Do instruction specific permission checks */ 3792 if (c->check_perm) { 3793 rc = c->check_perm(ctxt); 3794 if (rc != X86EMUL_CONTINUE) 3795 goto done; 3796 } 3797 3798 if (unlikely(ctxt->guest_mode) && c->intercept) { 3799 rc = emulator_check_intercept(ctxt, c->intercept, 3800 X86_ICPT_POST_EXCEPT); 3801 if (rc != X86EMUL_CONTINUE) 3802 goto done; 3803 } 3804 3805 if (c->rep_prefix && (c->d & String)) { 3806 /* All REP prefixes have the same first termination condition */ 3807 if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) { 3808 ctxt->eip = c->eip; 3809 goto done; 3810 } 3811 } 3812 3813 if ((c->src.type == OP_MEM) && !(c->d & NoAccess)) { 3814 rc = segmented_read(ctxt, c->src.addr.mem, 3815 c->src.valptr, c->src.bytes); 3816 if (rc != X86EMUL_CONTINUE) 3817 goto done; 3818 c->src.orig_val64 = c->src.val64; 3819 } 3820 3821 if (c->src2.type == OP_MEM) { 3822 rc = segmented_read(ctxt, c->src2.addr.mem, 3823 &c->src2.val, c->src2.bytes); 3824 if (rc != X86EMUL_CONTINUE) 3825 goto done; 3826 } 3827 3828 if ((c->d & DstMask) == ImplicitOps) 3829 goto special_insn; 3830 3831 3832 if ((c->dst.type == OP_MEM) && !(c->d & Mov)) { 3833 /* optimisation - avoid slow emulated read if Mov */ 3834 rc = segmented_read(ctxt, c->dst.addr.mem, 3835 &c->dst.val, c->dst.bytes); 3836 if (rc != X86EMUL_CONTINUE) 3837 goto done; 3838 } 3839 c->dst.orig_val = c->dst.val; 3840 3841 special_insn: 3842 3843 if (unlikely(ctxt->guest_mode) && c->intercept) { 3844 rc = emulator_check_intercept(ctxt, c->intercept, 3845 X86_ICPT_POST_MEMACCESS); 3846 if (rc != X86EMUL_CONTINUE) 3847 goto done; 3848 } 3849 3850 if (c->execute) { 3851 rc = c->execute(ctxt); 3852 if (rc != X86EMUL_CONTINUE) 3853 goto done; 3854 goto writeback; 3855 } 3856 3857 if (c->twobyte) 3858 goto twobyte_insn; 3859 3860 switch (c->b) { 3861 case 0x06: /* push es */ 3862 rc = emulate_push_sreg(ctxt, ops, VCPU_SREG_ES); 3863 break; 3864 case 0x07: /* pop es */ 3865 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_ES); 3866 break; 3867 case 0x0e: /* push cs */ 3868 rc = emulate_push_sreg(ctxt, ops, VCPU_SREG_CS); 3869 break; 3870 case 0x16: /* push ss */ 3871 rc = emulate_push_sreg(ctxt, ops, VCPU_SREG_SS); 3872 break; 3873 case 0x17: /* pop ss */ 3874 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_SS); 3875 break; 3876 case 0x1e: /* push ds */ 3877 rc = emulate_push_sreg(ctxt, ops, VCPU_SREG_DS); 3878 break; 3879 case 0x1f: /* pop ds */ 3880 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_DS); 3881 break; 3882 case 0x40 ... 0x47: /* inc r16/r32 */ 3883 emulate_1op("inc", c->dst, ctxt->eflags); 3884 break; 3885 case 0x48 ... 0x4f: /* dec r16/r32 */ 3886 emulate_1op("dec", c->dst, ctxt->eflags); 3887 break; 3888 case 0x63: /* movsxd */ 3889 if (ctxt->mode != X86EMUL_MODE_PROT64) 3890 goto cannot_emulate; 3891 c->dst.val = (s32) c->src.val; 3892 break; 3893 case 0x6c: /* insb */ 3894 case 0x6d: /* insw/insd */ 3895 c->src.val = c->regs[VCPU_REGS_RDX]; 3896 goto do_io_in; 3897 case 0x6e: /* outsb */ 3898 case 0x6f: /* outsw/outsd */ 3899 c->dst.val = c->regs[VCPU_REGS_RDX]; 3900 goto do_io_out; 3901 break; 3902 case 0x70 ... 0x7f: /* jcc (short) */ 3903 if (test_cc(c->b, ctxt->eflags)) 3904 jmp_rel(c, c->src.val); 3905 break; 3906 case 0x84 ... 0x85: 3907 test: 3908 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags); 3909 break; 3910 case 0x86 ... 0x87: /* xchg */ 3911 xchg: 3912 /* Write back the register source. */ 3913 c->src.val = c->dst.val; 3914 write_register_operand(&c->src); 3915 /* 3916 * Write back the memory destination with implicit LOCK 3917 * prefix. 3918 */ 3919 c->dst.val = c->src.orig_val; 3920 c->lock_prefix = 1; 3921 break; 3922 case 0x8c: /* mov r/m, sreg */ 3923 if (c->modrm_reg > VCPU_SREG_GS) { 3924 rc = emulate_ud(ctxt); 3925 goto done; 3926 } 3927 c->dst.val = get_segment_selector(ctxt, c->modrm_reg); 3928 break; 3929 case 0x8d: /* lea r16/r32, m */ 3930 c->dst.val = c->src.addr.mem.ea; 3931 break; 3932 case 0x8e: { /* mov seg, r/m16 */ 3933 uint16_t sel; 3934 3935 sel = c->src.val; 3936 3937 if (c->modrm_reg == VCPU_SREG_CS || 3938 c->modrm_reg > VCPU_SREG_GS) { 3939 rc = emulate_ud(ctxt); 3940 goto done; 3941 } 3942 3943 if (c->modrm_reg == VCPU_SREG_SS) 3944 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS; 3945 3946 rc = load_segment_descriptor(ctxt, ops, sel, c->modrm_reg); 3947 3948 c->dst.type = OP_NONE; /* Disable writeback. */ 3949 break; 3950 } 3951 case 0x8f: /* pop (sole member of Grp1a) */ 3952 rc = em_grp1a(ctxt); 3953 break; 3954 case 0x90 ... 0x97: /* nop / xchg reg, rax */ 3955 if (c->dst.addr.reg == &c->regs[VCPU_REGS_RAX]) 3956 break; 3957 goto xchg; 3958 case 0x98: /* cbw/cwde/cdqe */ 3959 switch (c->op_bytes) { 3960 case 2: c->dst.val = (s8)c->dst.val; break; 3961 case 4: c->dst.val = (s16)c->dst.val; break; 3962 case 8: c->dst.val = (s32)c->dst.val; break; 3963 } 3964 break; 3965 case 0xa8 ... 0xa9: /* test ax, imm */ 3966 goto test; 3967 case 0xc0 ... 0xc1: 3968 rc = em_grp2(ctxt); 3969 break; 3970 case 0xc3: /* ret */ 3971 c->dst.type = OP_REG; 3972 c->dst.addr.reg = &c->eip; 3973 c->dst.bytes = c->op_bytes; 3974 rc = em_pop(ctxt); 3975 break; 3976 case 0xc4: /* les */ 3977 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_ES); 3978 break; 3979 case 0xc5: /* lds */ 3980 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_DS); 3981 break; 3982 case 0xcb: /* ret far */ 3983 rc = emulate_ret_far(ctxt, ops); 3984 break; 3985 case 0xcc: /* int3 */ 3986 irq = 3; 3987 goto do_interrupt; 3988 case 0xcd: /* int n */ 3989 irq = c->src.val; 3990 do_interrupt: 3991 rc = emulate_int(ctxt, ops, irq); 3992 break; 3993 case 0xce: /* into */ 3994 if (ctxt->eflags & EFLG_OF) { 3995 irq = 4; 3996 goto do_interrupt; 3997 } 3998 break; 3999 case 0xcf: /* iret */ 4000 rc = emulate_iret(ctxt, ops); 4001 break; 4002 case 0xd0 ... 0xd1: /* Grp2 */ 4003 rc = em_grp2(ctxt); 4004 break; 4005 case 0xd2 ... 0xd3: /* Grp2 */ 4006 c->src.val = c->regs[VCPU_REGS_RCX]; 4007 rc = em_grp2(ctxt); 4008 break; 4009 case 0xe0 ... 0xe2: /* loop/loopz/loopnz */ 4010 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); 4011 if (address_mask(c, c->regs[VCPU_REGS_RCX]) != 0 && 4012 (c->b == 0xe2 || test_cc(c->b ^ 0x5, ctxt->eflags))) 4013 jmp_rel(c, c->src.val); 4014 break; 4015 case 0xe3: /* jcxz/jecxz/jrcxz */ 4016 if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) 4017 jmp_rel(c, c->src.val); 4018 break; 4019 case 0xe4: /* inb */ 4020 case 0xe5: /* in */ 4021 goto do_io_in; 4022 case 0xe6: /* outb */ 4023 case 0xe7: /* out */ 4024 goto do_io_out; 4025 case 0xe8: /* call (near) */ { 4026 long int rel = c->src.val; 4027 c->src.val = (unsigned long) c->eip; 4028 jmp_rel(c, rel); 4029 rc = em_push(ctxt); 4030 break; 4031 } 4032 case 0xe9: /* jmp rel */ 4033 goto jmp; 4034 case 0xea: /* jmp far */ 4035 rc = em_jmp_far(ctxt); 4036 break; 4037 case 0xeb: 4038 jmp: /* jmp rel short */ 4039 jmp_rel(c, c->src.val); 4040 c->dst.type = OP_NONE; /* Disable writeback. */ 4041 break; 4042 case 0xec: /* in al,dx */ 4043 case 0xed: /* in (e/r)ax,dx */ 4044 do_io_in: 4045 if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val, 4046 &c->dst.val)) 4047 goto done; /* IO is needed */ 4048 break; 4049 case 0xee: /* out dx,al */ 4050 case 0xef: /* out dx,(e/r)ax */ 4051 do_io_out: 4052 ops->pio_out_emulated(ctxt, c->src.bytes, c->dst.val, 4053 &c->src.val, 1); 4054 c->dst.type = OP_NONE; /* Disable writeback. */ 4055 break; 4056 case 0xf4: /* hlt */ 4057 ctxt->ops->halt(ctxt); 4058 break; 4059 case 0xf5: /* cmc */ 4060 /* complement carry flag from eflags reg */ 4061 ctxt->eflags ^= EFLG_CF; 4062 break; 4063 case 0xf6 ... 0xf7: /* Grp3 */ 4064 rc = em_grp3(ctxt); 4065 break; 4066 case 0xf8: /* clc */ 4067 ctxt->eflags &= ~EFLG_CF; 4068 break; 4069 case 0xf9: /* stc */ 4070 ctxt->eflags |= EFLG_CF; 4071 break; 4072 case 0xfa: /* cli */ 4073 if (emulator_bad_iopl(ctxt, ops)) { 4074 rc = emulate_gp(ctxt, 0); 4075 goto done; 4076 } else 4077 ctxt->eflags &= ~X86_EFLAGS_IF; 4078 break; 4079 case 0xfb: /* sti */ 4080 if (emulator_bad_iopl(ctxt, ops)) { 4081 rc = emulate_gp(ctxt, 0); 4082 goto done; 4083 } else { 4084 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI; 4085 ctxt->eflags |= X86_EFLAGS_IF; 4086 } 4087 break; 4088 case 0xfc: /* cld */ 4089 ctxt->eflags &= ~EFLG_DF; 4090 break; 4091 case 0xfd: /* std */ 4092 ctxt->eflags |= EFLG_DF; 4093 break; 4094 case 0xfe: /* Grp4 */ 4095 rc = em_grp45(ctxt); 4096 break; 4097 case 0xff: /* Grp5 */ 4098 rc = em_grp45(ctxt); 4099 break; 4100 default: 4101 goto cannot_emulate; 4102 } 4103 4104 if (rc != X86EMUL_CONTINUE) 4105 goto done; 4106 4107 writeback: 4108 rc = writeback(ctxt); 4109 if (rc != X86EMUL_CONTINUE) 4110 goto done; 4111 4112 /* 4113 * restore dst type in case the decoding will be reused 4114 * (happens for string instruction ) 4115 */ 4116 c->dst.type = saved_dst_type; 4117 4118 if ((c->d & SrcMask) == SrcSI) 4119 string_addr_inc(ctxt, seg_override(ctxt, c), 4120 VCPU_REGS_RSI, &c->src); 4121 4122 if ((c->d & DstMask) == DstDI) 4123 string_addr_inc(ctxt, VCPU_SREG_ES, VCPU_REGS_RDI, 4124 &c->dst); 4125 4126 if (c->rep_prefix && (c->d & String)) { 4127 struct read_cache *r = &ctxt->decode.io_read; 4128 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1); 4129 4130 if (!string_insn_completed(ctxt)) { 4131 /* 4132 * Re-enter guest when pio read ahead buffer is empty 4133 * or, if it is not used, after each 1024 iteration. 4134 */ 4135 if ((r->end != 0 || c->regs[VCPU_REGS_RCX] & 0x3ff) && 4136 (r->end == 0 || r->end != r->pos)) { 4137 /* 4138 * Reset read cache. Usually happens before 4139 * decode, but since instruction is restarted 4140 * we have to do it here. 4141 */ 4142 ctxt->decode.mem_read.end = 0; 4143 return EMULATION_RESTART; 4144 } 4145 goto done; /* skip rip writeback */ 4146 } 4147 } 4148 4149 ctxt->eip = c->eip; 4150 4151 done: 4152 if (rc == X86EMUL_PROPAGATE_FAULT) 4153 ctxt->have_exception = true; 4154 if (rc == X86EMUL_INTERCEPTED) 4155 return EMULATION_INTERCEPTED; 4156 4157 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK; 4158 4159 twobyte_insn: 4160 switch (c->b) { 4161 case 0x05: /* syscall */ 4162 rc = emulate_syscall(ctxt, ops); 4163 break; 4164 case 0x06: 4165 rc = em_clts(ctxt); 4166 break; 4167 case 0x09: /* wbinvd */ 4168 (ctxt->ops->wbinvd)(ctxt); 4169 break; 4170 case 0x08: /* invd */ 4171 case 0x0d: /* GrpP (prefetch) */ 4172 case 0x18: /* Grp16 (prefetch/nop) */ 4173 break; 4174 case 0x20: /* mov cr, reg */ 4175 c->dst.val = ops->get_cr(ctxt, c->modrm_reg); 4176 break; 4177 case 0x21: /* mov from dr to reg */ 4178 ops->get_dr(ctxt, c->modrm_reg, &c->dst.val); 4179 break; 4180 case 0x22: /* mov reg, cr */ 4181 if (ops->set_cr(ctxt, c->modrm_reg, c->src.val)) { 4182 emulate_gp(ctxt, 0); 4183 rc = X86EMUL_PROPAGATE_FAULT; 4184 goto done; 4185 } 4186 c->dst.type = OP_NONE; 4187 break; 4188 case 0x23: /* mov from reg to dr */ 4189 if (ops->set_dr(ctxt, c->modrm_reg, c->src.val & 4190 ((ctxt->mode == X86EMUL_MODE_PROT64) ? 4191 ~0ULL : ~0U)) < 0) { 4192 /* #UD condition is already handled by the code above */ 4193 emulate_gp(ctxt, 0); 4194 rc = X86EMUL_PROPAGATE_FAULT; 4195 goto done; 4196 } 4197 4198 c->dst.type = OP_NONE; /* no writeback */ 4199 break; 4200 case 0x30: 4201 /* wrmsr */ 4202 msr_data = (u32)c->regs[VCPU_REGS_RAX] 4203 | ((u64)c->regs[VCPU_REGS_RDX] << 32); 4204 if (ops->set_msr(ctxt, c->regs[VCPU_REGS_RCX], msr_data)) { 4205 emulate_gp(ctxt, 0); 4206 rc = X86EMUL_PROPAGATE_FAULT; 4207 goto done; 4208 } 4209 rc = X86EMUL_CONTINUE; 4210 break; 4211 case 0x32: 4212 /* rdmsr */ 4213 if (ops->get_msr(ctxt, c->regs[VCPU_REGS_RCX], &msr_data)) { 4214 emulate_gp(ctxt, 0); 4215 rc = X86EMUL_PROPAGATE_FAULT; 4216 goto done; 4217 } else { 4218 c->regs[VCPU_REGS_RAX] = (u32)msr_data; 4219 c->regs[VCPU_REGS_RDX] = msr_data >> 32; 4220 } 4221 rc = X86EMUL_CONTINUE; 4222 break; 4223 case 0x34: /* sysenter */ 4224 rc = emulate_sysenter(ctxt, ops); 4225 break; 4226 case 0x35: /* sysexit */ 4227 rc = emulate_sysexit(ctxt, ops); 4228 break; 4229 case 0x40 ... 0x4f: /* cmov */ 4230 c->dst.val = c->dst.orig_val = c->src.val; 4231 if (!test_cc(c->b, ctxt->eflags)) 4232 c->dst.type = OP_NONE; /* no writeback */ 4233 break; 4234 case 0x80 ... 0x8f: /* jnz rel, etc*/ 4235 if (test_cc(c->b, ctxt->eflags)) 4236 jmp_rel(c, c->src.val); 4237 break; 4238 case 0x90 ... 0x9f: /* setcc r/m8 */ 4239 c->dst.val = test_cc(c->b, ctxt->eflags); 4240 break; 4241 case 0xa0: /* push fs */ 4242 rc = emulate_push_sreg(ctxt, ops, VCPU_SREG_FS); 4243 break; 4244 case 0xa1: /* pop fs */ 4245 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_FS); 4246 break; 4247 case 0xa3: 4248 bt: /* bt */ 4249 c->dst.type = OP_NONE; 4250 /* only subword offset */ 4251 c->src.val &= (c->dst.bytes << 3) - 1; 4252 emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags); 4253 break; 4254 case 0xa4: /* shld imm8, r, r/m */ 4255 case 0xa5: /* shld cl, r, r/m */ 4256 emulate_2op_cl("shld", c->src2, c->src, c->dst, ctxt->eflags); 4257 break; 4258 case 0xa8: /* push gs */ 4259 rc = emulate_push_sreg(ctxt, ops, VCPU_SREG_GS); 4260 break; 4261 case 0xa9: /* pop gs */ 4262 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_GS); 4263 break; 4264 case 0xab: 4265 bts: /* bts */ 4266 emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags); 4267 break; 4268 case 0xac: /* shrd imm8, r, r/m */ 4269 case 0xad: /* shrd cl, r, r/m */ 4270 emulate_2op_cl("shrd", c->src2, c->src, c->dst, ctxt->eflags); 4271 break; 4272 case 0xae: /* clflush */ 4273 break; 4274 case 0xb0 ... 0xb1: /* cmpxchg */ 4275 /* 4276 * Save real source value, then compare EAX against 4277 * destination. 4278 */ 4279 c->src.orig_val = c->src.val; 4280 c->src.val = c->regs[VCPU_REGS_RAX]; 4281 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags); 4282 if (ctxt->eflags & EFLG_ZF) { 4283 /* Success: write back to memory. */ 4284 c->dst.val = c->src.orig_val; 4285 } else { 4286 /* Failure: write the value we saw to EAX. */ 4287 c->dst.type = OP_REG; 4288 c->dst.addr.reg = (unsigned long *)&c->regs[VCPU_REGS_RAX]; 4289 } 4290 break; 4291 case 0xb2: /* lss */ 4292 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_SS); 4293 break; 4294 case 0xb3: 4295 btr: /* btr */ 4296 emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags); 4297 break; 4298 case 0xb4: /* lfs */ 4299 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_FS); 4300 break; 4301 case 0xb5: /* lgs */ 4302 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_GS); 4303 break; 4304 case 0xb6 ... 0xb7: /* movzx */ 4305 c->dst.bytes = c->op_bytes; 4306 c->dst.val = (c->d & ByteOp) ? (u8) c->src.val 4307 : (u16) c->src.val; 4308 break; 4309 case 0xba: /* Grp8 */ 4310 switch (c->modrm_reg & 3) { 4311 case 0: 4312 goto bt; 4313 case 1: 4314 goto bts; 4315 case 2: 4316 goto btr; 4317 case 3: 4318 goto btc; 4319 } 4320 break; 4321 case 0xbb: 4322 btc: /* btc */ 4323 emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags); 4324 break; 4325 case 0xbc: { /* bsf */ 4326 u8 zf; 4327 __asm__ ("bsf %2, %0; setz %1" 4328 : "=r"(c->dst.val), "=q"(zf) 4329 : "r"(c->src.val)); 4330 ctxt->eflags &= ~X86_EFLAGS_ZF; 4331 if (zf) { 4332 ctxt->eflags |= X86_EFLAGS_ZF; 4333 c->dst.type = OP_NONE; /* Disable writeback. */ 4334 } 4335 break; 4336 } 4337 case 0xbd: { /* bsr */ 4338 u8 zf; 4339 __asm__ ("bsr %2, %0; setz %1" 4340 : "=r"(c->dst.val), "=q"(zf) 4341 : "r"(c->src.val)); 4342 ctxt->eflags &= ~X86_EFLAGS_ZF; 4343 if (zf) { 4344 ctxt->eflags |= X86_EFLAGS_ZF; 4345 c->dst.type = OP_NONE; /* Disable writeback. */ 4346 } 4347 break; 4348 } 4349 case 0xbe ... 0xbf: /* movsx */ 4350 c->dst.bytes = c->op_bytes; 4351 c->dst.val = (c->d & ByteOp) ? (s8) c->src.val : 4352 (s16) c->src.val; 4353 break; 4354 case 0xc0 ... 0xc1: /* xadd */ 4355 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags); 4356 /* Write back the register source. */ 4357 c->src.val = c->dst.orig_val; 4358 write_register_operand(&c->src); 4359 break; 4360 case 0xc3: /* movnti */ 4361 c->dst.bytes = c->op_bytes; 4362 c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val : 4363 (u64) c->src.val; 4364 break; 4365 case 0xc7: /* Grp9 (cmpxchg8b) */ 4366 rc = em_grp9(ctxt); 4367 break; 4368 default: 4369 goto cannot_emulate; 4370 } 4371 4372 if (rc != X86EMUL_CONTINUE) 4373 goto done; 4374 4375 goto writeback; 4376 4377 cannot_emulate: 4378 return EMULATION_FAILED; 4379 } 4380