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KVM: x86: fix RSM into 64-bit protected mode
[deliverable/linux.git] / arch / x86 / kvm / emulate.c
1 /******************************************************************************
2 * emulate.c
3 *
4 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
5 *
6 * Copyright (c) 2005 Keir Fraser
7 *
8 * Linux coding style, mod r/m decoder, segment base fixes, real-mode
9 * privileged instructions:
10 *
11 * Copyright (C) 2006 Qumranet
12 * 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 #include <linux/stringify.h>
28 #include <asm/debugreg.h>
29
30 #include "x86.h"
31 #include "tss.h"
32
33 /*
34 * Operand types
35 */
36 #define OpNone 0ull
37 #define OpImplicit 1ull /* No generic decode */
38 #define OpReg 2ull /* Register */
39 #define OpMem 3ull /* Memory */
40 #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */
41 #define OpDI 5ull /* ES:DI/EDI/RDI */
42 #define OpMem64 6ull /* Memory, 64-bit */
43 #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */
44 #define OpDX 8ull /* DX register */
45 #define OpCL 9ull /* CL register (for shifts) */
46 #define OpImmByte 10ull /* 8-bit sign extended immediate */
47 #define OpOne 11ull /* Implied 1 */
48 #define OpImm 12ull /* Sign extended up to 32-bit immediate */
49 #define OpMem16 13ull /* Memory operand (16-bit). */
50 #define OpMem32 14ull /* Memory operand (32-bit). */
51 #define OpImmU 15ull /* Immediate operand, zero extended */
52 #define OpSI 16ull /* SI/ESI/RSI */
53 #define OpImmFAddr 17ull /* Immediate far address */
54 #define OpMemFAddr 18ull /* Far address in memory */
55 #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */
56 #define OpES 20ull /* ES */
57 #define OpCS 21ull /* CS */
58 #define OpSS 22ull /* SS */
59 #define OpDS 23ull /* DS */
60 #define OpFS 24ull /* FS */
61 #define OpGS 25ull /* GS */
62 #define OpMem8 26ull /* 8-bit zero extended memory operand */
63 #define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */
64 #define OpXLat 28ull /* memory at BX/EBX/RBX + zero-extended AL */
65 #define OpAccLo 29ull /* Low part of extended acc (AX/AX/EAX/RAX) */
66 #define OpAccHi 30ull /* High part of extended acc (-/DX/EDX/RDX) */
67
68 #define OpBits 5 /* Width of operand field */
69 #define OpMask ((1ull << OpBits) - 1)
70
71 /*
72 * Opcode effective-address decode tables.
73 * Note that we only emulate instructions that have at least one memory
74 * operand (excluding implicit stack references). We assume that stack
75 * references and instruction fetches will never occur in special memory
76 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
77 * not be handled.
78 */
79
80 /* Operand sizes: 8-bit operands or specified/overridden size. */
81 #define ByteOp (1<<0) /* 8-bit operands. */
82 /* Destination operand type. */
83 #define DstShift 1
84 #define ImplicitOps (OpImplicit << DstShift)
85 #define DstReg (OpReg << DstShift)
86 #define DstMem (OpMem << DstShift)
87 #define DstAcc (OpAcc << DstShift)
88 #define DstDI (OpDI << DstShift)
89 #define DstMem64 (OpMem64 << DstShift)
90 #define DstMem16 (OpMem16 << DstShift)
91 #define DstImmUByte (OpImmUByte << DstShift)
92 #define DstDX (OpDX << DstShift)
93 #define DstAccLo (OpAccLo << DstShift)
94 #define DstMask (OpMask << DstShift)
95 /* Source operand type. */
96 #define SrcShift 6
97 #define SrcNone (OpNone << SrcShift)
98 #define SrcReg (OpReg << SrcShift)
99 #define SrcMem (OpMem << SrcShift)
100 #define SrcMem16 (OpMem16 << SrcShift)
101 #define SrcMem32 (OpMem32 << SrcShift)
102 #define SrcImm (OpImm << SrcShift)
103 #define SrcImmByte (OpImmByte << SrcShift)
104 #define SrcOne (OpOne << SrcShift)
105 #define SrcImmUByte (OpImmUByte << SrcShift)
106 #define SrcImmU (OpImmU << SrcShift)
107 #define SrcSI (OpSI << SrcShift)
108 #define SrcXLat (OpXLat << SrcShift)
109 #define SrcImmFAddr (OpImmFAddr << SrcShift)
110 #define SrcMemFAddr (OpMemFAddr << SrcShift)
111 #define SrcAcc (OpAcc << SrcShift)
112 #define SrcImmU16 (OpImmU16 << SrcShift)
113 #define SrcImm64 (OpImm64 << SrcShift)
114 #define SrcDX (OpDX << SrcShift)
115 #define SrcMem8 (OpMem8 << SrcShift)
116 #define SrcAccHi (OpAccHi << SrcShift)
117 #define SrcMask (OpMask << SrcShift)
118 #define BitOp (1<<11)
119 #define MemAbs (1<<12) /* Memory operand is absolute displacement */
120 #define String (1<<13) /* String instruction (rep capable) */
121 #define Stack (1<<14) /* Stack instruction (push/pop) */
122 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */
123 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */
124 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */
125 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */
126 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */
127 #define Escape (5<<15) /* Escape to coprocessor instruction */
128 #define InstrDual (6<<15) /* Alternate instruction decoding of mod == 3 */
129 #define ModeDual (7<<15) /* Different instruction for 32/64 bit */
130 #define Sse (1<<18) /* SSE Vector instruction */
131 /* Generic ModRM decode. */
132 #define ModRM (1<<19)
133 /* Destination is only written; never read. */
134 #define Mov (1<<20)
135 /* Misc flags */
136 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */
137 #define EmulateOnUD (1<<22) /* Emulate if unsupported by the host */
138 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
139 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */
140 #define Undefined (1<<25) /* No Such Instruction */
141 #define Lock (1<<26) /* lock prefix is allowed for the instruction */
142 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
143 #define No64 (1<<28)
144 #define PageTable (1 << 29) /* instruction used to write page table */
145 #define NotImpl (1 << 30) /* instruction is not implemented */
146 /* Source 2 operand type */
147 #define Src2Shift (31)
148 #define Src2None (OpNone << Src2Shift)
149 #define Src2Mem (OpMem << Src2Shift)
150 #define Src2CL (OpCL << Src2Shift)
151 #define Src2ImmByte (OpImmByte << Src2Shift)
152 #define Src2One (OpOne << Src2Shift)
153 #define Src2Imm (OpImm << Src2Shift)
154 #define Src2ES (OpES << Src2Shift)
155 #define Src2CS (OpCS << Src2Shift)
156 #define Src2SS (OpSS << Src2Shift)
157 #define Src2DS (OpDS << Src2Shift)
158 #define Src2FS (OpFS << Src2Shift)
159 #define Src2GS (OpGS << Src2Shift)
160 #define Src2Mask (OpMask << Src2Shift)
161 #define Mmx ((u64)1 << 40) /* MMX Vector instruction */
162 #define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */
163 #define Unaligned ((u64)1 << 42) /* Explicitly unaligned (e.g. MOVDQU) */
164 #define Avx ((u64)1 << 43) /* Advanced Vector Extensions */
165 #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */
166 #define NoWrite ((u64)1 << 45) /* No writeback */
167 #define SrcWrite ((u64)1 << 46) /* Write back src operand */
168 #define NoMod ((u64)1 << 47) /* Mod field is ignored */
169 #define Intercept ((u64)1 << 48) /* Has valid intercept field */
170 #define CheckPerm ((u64)1 << 49) /* Has valid check_perm field */
171 #define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */
172 #define NearBranch ((u64)1 << 52) /* Near branches */
173 #define No16 ((u64)1 << 53) /* No 16 bit operand */
174 #define IncSP ((u64)1 << 54) /* SP is incremented before ModRM calc */
175
176 #define DstXacc (DstAccLo | SrcAccHi | SrcWrite)
177
178 #define X2(x...) x, x
179 #define X3(x...) X2(x), x
180 #define X4(x...) X2(x), X2(x)
181 #define X5(x...) X4(x), x
182 #define X6(x...) X4(x), X2(x)
183 #define X7(x...) X4(x), X3(x)
184 #define X8(x...) X4(x), X4(x)
185 #define X16(x...) X8(x), X8(x)
186
187 #define NR_FASTOP (ilog2(sizeof(ulong)) + 1)
188 #define FASTOP_SIZE 8
189
190 /*
191 * fastop functions have a special calling convention:
192 *
193 * dst: rax (in/out)
194 * src: rdx (in/out)
195 * src2: rcx (in)
196 * flags: rflags (in/out)
197 * ex: rsi (in:fastop pointer, out:zero if exception)
198 *
199 * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
200 * different operand sizes can be reached by calculation, rather than a jump
201 * table (which would be bigger than the code).
202 *
203 * fastop functions are declared as taking a never-defined fastop parameter,
204 * so they can't be called from C directly.
205 */
206
207 struct fastop;
208
209 struct opcode {
210 u64 flags : 56;
211 u64 intercept : 8;
212 union {
213 int (*execute)(struct x86_emulate_ctxt *ctxt);
214 const struct opcode *group;
215 const struct group_dual *gdual;
216 const struct gprefix *gprefix;
217 const struct escape *esc;
218 const struct instr_dual *idual;
219 const struct mode_dual *mdual;
220 void (*fastop)(struct fastop *fake);
221 } u;
222 int (*check_perm)(struct x86_emulate_ctxt *ctxt);
223 };
224
225 struct group_dual {
226 struct opcode mod012[8];
227 struct opcode mod3[8];
228 };
229
230 struct gprefix {
231 struct opcode pfx_no;
232 struct opcode pfx_66;
233 struct opcode pfx_f2;
234 struct opcode pfx_f3;
235 };
236
237 struct escape {
238 struct opcode op[8];
239 struct opcode high[64];
240 };
241
242 struct instr_dual {
243 struct opcode mod012;
244 struct opcode mod3;
245 };
246
247 struct mode_dual {
248 struct opcode mode32;
249 struct opcode mode64;
250 };
251
252 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a
253
254 enum x86_transfer_type {
255 X86_TRANSFER_NONE,
256 X86_TRANSFER_CALL_JMP,
257 X86_TRANSFER_RET,
258 X86_TRANSFER_TASK_SWITCH,
259 };
260
261 static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr)
262 {
263 if (!(ctxt->regs_valid & (1 << nr))) {
264 ctxt->regs_valid |= 1 << nr;
265 ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr);
266 }
267 return ctxt->_regs[nr];
268 }
269
270 static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr)
271 {
272 ctxt->regs_valid |= 1 << nr;
273 ctxt->regs_dirty |= 1 << nr;
274 return &ctxt->_regs[nr];
275 }
276
277 static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr)
278 {
279 reg_read(ctxt, nr);
280 return reg_write(ctxt, nr);
281 }
282
283 static void writeback_registers(struct x86_emulate_ctxt *ctxt)
284 {
285 unsigned reg;
286
287 for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16)
288 ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]);
289 }
290
291 static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
292 {
293 ctxt->regs_dirty = 0;
294 ctxt->regs_valid = 0;
295 }
296
297 /*
298 * These EFLAGS bits are restored from saved value during emulation, and
299 * any changes are written back to the saved value after emulation.
300 */
301 #define EFLAGS_MASK (X86_EFLAGS_OF|X86_EFLAGS_SF|X86_EFLAGS_ZF|X86_EFLAGS_AF|\
302 X86_EFLAGS_PF|X86_EFLAGS_CF)
303
304 #ifdef CONFIG_X86_64
305 #define ON64(x) x
306 #else
307 #define ON64(x)
308 #endif
309
310 static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
311
312 #define FOP_ALIGN ".align " __stringify(FASTOP_SIZE) " \n\t"
313 #define FOP_RET "ret \n\t"
314
315 #define FOP_START(op) \
316 extern void em_##op(struct fastop *fake); \
317 asm(".pushsection .text, \"ax\" \n\t" \
318 ".global em_" #op " \n\t" \
319 FOP_ALIGN \
320 "em_" #op ": \n\t"
321
322 #define FOP_END \
323 ".popsection")
324
325 #define FOPNOP() FOP_ALIGN FOP_RET
326
327 #define FOP1E(op, dst) \
328 FOP_ALIGN "10: " #op " %" #dst " \n\t" FOP_RET
329
330 #define FOP1EEX(op, dst) \
331 FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception)
332
333 #define FASTOP1(op) \
334 FOP_START(op) \
335 FOP1E(op##b, al) \
336 FOP1E(op##w, ax) \
337 FOP1E(op##l, eax) \
338 ON64(FOP1E(op##q, rax)) \
339 FOP_END
340
341 /* 1-operand, using src2 (for MUL/DIV r/m) */
342 #define FASTOP1SRC2(op, name) \
343 FOP_START(name) \
344 FOP1E(op, cl) \
345 FOP1E(op, cx) \
346 FOP1E(op, ecx) \
347 ON64(FOP1E(op, rcx)) \
348 FOP_END
349
350 /* 1-operand, using src2 (for MUL/DIV r/m), with exceptions */
351 #define FASTOP1SRC2EX(op, name) \
352 FOP_START(name) \
353 FOP1EEX(op, cl) \
354 FOP1EEX(op, cx) \
355 FOP1EEX(op, ecx) \
356 ON64(FOP1EEX(op, rcx)) \
357 FOP_END
358
359 #define FOP2E(op, dst, src) \
360 FOP_ALIGN #op " %" #src ", %" #dst " \n\t" FOP_RET
361
362 #define FASTOP2(op) \
363 FOP_START(op) \
364 FOP2E(op##b, al, dl) \
365 FOP2E(op##w, ax, dx) \
366 FOP2E(op##l, eax, edx) \
367 ON64(FOP2E(op##q, rax, rdx)) \
368 FOP_END
369
370 /* 2 operand, word only */
371 #define FASTOP2W(op) \
372 FOP_START(op) \
373 FOPNOP() \
374 FOP2E(op##w, ax, dx) \
375 FOP2E(op##l, eax, edx) \
376 ON64(FOP2E(op##q, rax, rdx)) \
377 FOP_END
378
379 /* 2 operand, src is CL */
380 #define FASTOP2CL(op) \
381 FOP_START(op) \
382 FOP2E(op##b, al, cl) \
383 FOP2E(op##w, ax, cl) \
384 FOP2E(op##l, eax, cl) \
385 ON64(FOP2E(op##q, rax, cl)) \
386 FOP_END
387
388 /* 2 operand, src and dest are reversed */
389 #define FASTOP2R(op, name) \
390 FOP_START(name) \
391 FOP2E(op##b, dl, al) \
392 FOP2E(op##w, dx, ax) \
393 FOP2E(op##l, edx, eax) \
394 ON64(FOP2E(op##q, rdx, rax)) \
395 FOP_END
396
397 #define FOP3E(op, dst, src, src2) \
398 FOP_ALIGN #op " %" #src2 ", %" #src ", %" #dst " \n\t" FOP_RET
399
400 /* 3-operand, word-only, src2=cl */
401 #define FASTOP3WCL(op) \
402 FOP_START(op) \
403 FOPNOP() \
404 FOP3E(op##w, ax, dx, cl) \
405 FOP3E(op##l, eax, edx, cl) \
406 ON64(FOP3E(op##q, rax, rdx, cl)) \
407 FOP_END
408
409 /* Special case for SETcc - 1 instruction per cc */
410 #define FOP_SETCC(op) ".align 4; " #op " %al; ret \n\t"
411
412 asm(".global kvm_fastop_exception \n"
413 "kvm_fastop_exception: xor %esi, %esi; ret");
414
415 FOP_START(setcc)
416 FOP_SETCC(seto)
417 FOP_SETCC(setno)
418 FOP_SETCC(setc)
419 FOP_SETCC(setnc)
420 FOP_SETCC(setz)
421 FOP_SETCC(setnz)
422 FOP_SETCC(setbe)
423 FOP_SETCC(setnbe)
424 FOP_SETCC(sets)
425 FOP_SETCC(setns)
426 FOP_SETCC(setp)
427 FOP_SETCC(setnp)
428 FOP_SETCC(setl)
429 FOP_SETCC(setnl)
430 FOP_SETCC(setle)
431 FOP_SETCC(setnle)
432 FOP_END;
433
434 FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET
435 FOP_END;
436
437 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
438 enum x86_intercept intercept,
439 enum x86_intercept_stage stage)
440 {
441 struct x86_instruction_info info = {
442 .intercept = intercept,
443 .rep_prefix = ctxt->rep_prefix,
444 .modrm_mod = ctxt->modrm_mod,
445 .modrm_reg = ctxt->modrm_reg,
446 .modrm_rm = ctxt->modrm_rm,
447 .src_val = ctxt->src.val64,
448 .dst_val = ctxt->dst.val64,
449 .src_bytes = ctxt->src.bytes,
450 .dst_bytes = ctxt->dst.bytes,
451 .ad_bytes = ctxt->ad_bytes,
452 .next_rip = ctxt->eip,
453 };
454
455 return ctxt->ops->intercept(ctxt, &info, stage);
456 }
457
458 static void assign_masked(ulong *dest, ulong src, ulong mask)
459 {
460 *dest = (*dest & ~mask) | (src & mask);
461 }
462
463 static void assign_register(unsigned long *reg, u64 val, int bytes)
464 {
465 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
466 switch (bytes) {
467 case 1:
468 *(u8 *)reg = (u8)val;
469 break;
470 case 2:
471 *(u16 *)reg = (u16)val;
472 break;
473 case 4:
474 *reg = (u32)val;
475 break; /* 64b: zero-extend */
476 case 8:
477 *reg = val;
478 break;
479 }
480 }
481
482 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
483 {
484 return (1UL << (ctxt->ad_bytes << 3)) - 1;
485 }
486
487 static ulong stack_mask(struct x86_emulate_ctxt *ctxt)
488 {
489 u16 sel;
490 struct desc_struct ss;
491
492 if (ctxt->mode == X86EMUL_MODE_PROT64)
493 return ~0UL;
494 ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS);
495 return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */
496 }
497
498 static int stack_size(struct x86_emulate_ctxt *ctxt)
499 {
500 return (__fls(stack_mask(ctxt)) + 1) >> 3;
501 }
502
503 /* Access/update address held in a register, based on addressing mode. */
504 static inline unsigned long
505 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg)
506 {
507 if (ctxt->ad_bytes == sizeof(unsigned long))
508 return reg;
509 else
510 return reg & ad_mask(ctxt);
511 }
512
513 static inline unsigned long
514 register_address(struct x86_emulate_ctxt *ctxt, int reg)
515 {
516 return address_mask(ctxt, reg_read(ctxt, reg));
517 }
518
519 static void masked_increment(ulong *reg, ulong mask, int inc)
520 {
521 assign_masked(reg, *reg + inc, mask);
522 }
523
524 static inline void
525 register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc)
526 {
527 ulong *preg = reg_rmw(ctxt, reg);
528
529 assign_register(preg, *preg + inc, ctxt->ad_bytes);
530 }
531
532 static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)
533 {
534 masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc);
535 }
536
537 static u32 desc_limit_scaled(struct desc_struct *desc)
538 {
539 u32 limit = get_desc_limit(desc);
540
541 return desc->g ? (limit << 12) | 0xfff : limit;
542 }
543
544 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
545 {
546 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
547 return 0;
548
549 return ctxt->ops->get_cached_segment_base(ctxt, seg);
550 }
551
552 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
553 u32 error, bool valid)
554 {
555 WARN_ON(vec > 0x1f);
556 ctxt->exception.vector = vec;
557 ctxt->exception.error_code = error;
558 ctxt->exception.error_code_valid = valid;
559 return X86EMUL_PROPAGATE_FAULT;
560 }
561
562 static int emulate_db(struct x86_emulate_ctxt *ctxt)
563 {
564 return emulate_exception(ctxt, DB_VECTOR, 0, false);
565 }
566
567 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
568 {
569 return emulate_exception(ctxt, GP_VECTOR, err, true);
570 }
571
572 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err)
573 {
574 return emulate_exception(ctxt, SS_VECTOR, err, true);
575 }
576
577 static int emulate_ud(struct x86_emulate_ctxt *ctxt)
578 {
579 return emulate_exception(ctxt, UD_VECTOR, 0, false);
580 }
581
582 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)
583 {
584 return emulate_exception(ctxt, TS_VECTOR, err, true);
585 }
586
587 static int emulate_de(struct x86_emulate_ctxt *ctxt)
588 {
589 return emulate_exception(ctxt, DE_VECTOR, 0, false);
590 }
591
592 static int emulate_nm(struct x86_emulate_ctxt *ctxt)
593 {
594 return emulate_exception(ctxt, NM_VECTOR, 0, false);
595 }
596
597 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
598 {
599 u16 selector;
600 struct desc_struct desc;
601
602 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg);
603 return selector;
604 }
605
606 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector,
607 unsigned seg)
608 {
609 u16 dummy;
610 u32 base3;
611 struct desc_struct desc;
612
613 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg);
614 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg);
615 }
616
617 /*
618 * x86 defines three classes of vector instructions: explicitly
619 * aligned, explicitly unaligned, and the rest, which change behaviour
620 * depending on whether they're AVX encoded or not.
621 *
622 * Also included is CMPXCHG16B which is not a vector instruction, yet it is
623 * subject to the same check.
624 */
625 static bool insn_aligned(struct x86_emulate_ctxt *ctxt, unsigned size)
626 {
627 if (likely(size < 16))
628 return false;
629
630 if (ctxt->d & Aligned)
631 return true;
632 else if (ctxt->d & Unaligned)
633 return false;
634 else if (ctxt->d & Avx)
635 return false;
636 else
637 return true;
638 }
639
640 static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
641 struct segmented_address addr,
642 unsigned *max_size, unsigned size,
643 bool write, bool fetch,
644 enum x86emul_mode mode, ulong *linear)
645 {
646 struct desc_struct desc;
647 bool usable;
648 ulong la;
649 u32 lim;
650 u16 sel;
651
652 la = seg_base(ctxt, addr.seg) + addr.ea;
653 *linear = la;
654 *max_size = 0;
655 switch (mode) {
656 case X86EMUL_MODE_PROT64:
657 if (is_noncanonical_address(la))
658 goto bad;
659
660 *max_size = min_t(u64, ~0u, (1ull << 48) - la);
661 if (size > *max_size)
662 goto bad;
663 break;
664 default:
665 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
666 addr.seg);
667 if (!usable)
668 goto bad;
669 /* code segment in protected mode or read-only data segment */
670 if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8))
671 || !(desc.type & 2)) && write)
672 goto bad;
673 /* unreadable code segment */
674 if (!fetch && (desc.type & 8) && !(desc.type & 2))
675 goto bad;
676 lim = desc_limit_scaled(&desc);
677 if (!(desc.type & 8) && (desc.type & 4)) {
678 /* expand-down segment */
679 if (addr.ea <= lim)
680 goto bad;
681 lim = desc.d ? 0xffffffff : 0xffff;
682 }
683 if (addr.ea > lim)
684 goto bad;
685 if (lim == 0xffffffff)
686 *max_size = ~0u;
687 else {
688 *max_size = (u64)lim + 1 - addr.ea;
689 if (size > *max_size)
690 goto bad;
691 }
692 la &= (u32)-1;
693 break;
694 }
695 if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
696 return emulate_gp(ctxt, 0);
697 return X86EMUL_CONTINUE;
698 bad:
699 if (addr.seg == VCPU_SREG_SS)
700 return emulate_ss(ctxt, 0);
701 else
702 return emulate_gp(ctxt, 0);
703 }
704
705 static int linearize(struct x86_emulate_ctxt *ctxt,
706 struct segmented_address addr,
707 unsigned size, bool write,
708 ulong *linear)
709 {
710 unsigned max_size;
711 return __linearize(ctxt, addr, &max_size, size, write, false,
712 ctxt->mode, linear);
713 }
714
715 static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst,
716 enum x86emul_mode mode)
717 {
718 ulong linear;
719 int rc;
720 unsigned max_size;
721 struct segmented_address addr = { .seg = VCPU_SREG_CS,
722 .ea = dst };
723
724 if (ctxt->op_bytes != sizeof(unsigned long))
725 addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1);
726 rc = __linearize(ctxt, addr, &max_size, 1, false, true, mode, &linear);
727 if (rc == X86EMUL_CONTINUE)
728 ctxt->_eip = addr.ea;
729 return rc;
730 }
731
732 static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst)
733 {
734 return assign_eip(ctxt, dst, ctxt->mode);
735 }
736
737 static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst,
738 const struct desc_struct *cs_desc)
739 {
740 enum x86emul_mode mode = ctxt->mode;
741 int rc;
742
743 #ifdef CONFIG_X86_64
744 if (ctxt->mode >= X86EMUL_MODE_PROT16) {
745 if (cs_desc->l) {
746 u64 efer = 0;
747
748 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
749 if (efer & EFER_LMA)
750 mode = X86EMUL_MODE_PROT64;
751 } else
752 mode = X86EMUL_MODE_PROT32; /* temporary value */
753 }
754 #endif
755 if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32)
756 mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
757 rc = assign_eip(ctxt, dst, mode);
758 if (rc == X86EMUL_CONTINUE)
759 ctxt->mode = mode;
760 return rc;
761 }
762
763 static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
764 {
765 return assign_eip_near(ctxt, ctxt->_eip + rel);
766 }
767
768 static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
769 struct segmented_address addr,
770 void *data,
771 unsigned size)
772 {
773 int rc;
774 ulong linear;
775
776 rc = linearize(ctxt, addr, size, false, &linear);
777 if (rc != X86EMUL_CONTINUE)
778 return rc;
779 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
780 }
781
782 /*
783 * Prefetch the remaining bytes of the instruction without crossing page
784 * boundary if they are not in fetch_cache yet.
785 */
786 static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
787 {
788 int rc;
789 unsigned size, max_size;
790 unsigned long linear;
791 int cur_size = ctxt->fetch.end - ctxt->fetch.data;
792 struct segmented_address addr = { .seg = VCPU_SREG_CS,
793 .ea = ctxt->eip + cur_size };
794
795 /*
796 * We do not know exactly how many bytes will be needed, and
797 * __linearize is expensive, so fetch as much as possible. We
798 * just have to avoid going beyond the 15 byte limit, the end
799 * of the segment, or the end of the page.
800 *
801 * __linearize is called with size 0 so that it does not do any
802 * boundary check itself. Instead, we use max_size to check
803 * against op_size.
804 */
805 rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode,
806 &linear);
807 if (unlikely(rc != X86EMUL_CONTINUE))
808 return rc;
809
810 size = min_t(unsigned, 15UL ^ cur_size, max_size);
811 size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear));
812
813 /*
814 * One instruction can only straddle two pages,
815 * and one has been loaded at the beginning of
816 * x86_decode_insn. So, if not enough bytes
817 * still, we must have hit the 15-byte boundary.
818 */
819 if (unlikely(size < op_size))
820 return emulate_gp(ctxt, 0);
821
822 rc = ctxt->ops->fetch(ctxt, linear, ctxt->fetch.end,
823 size, &ctxt->exception);
824 if (unlikely(rc != X86EMUL_CONTINUE))
825 return rc;
826 ctxt->fetch.end += size;
827 return X86EMUL_CONTINUE;
828 }
829
830 static __always_inline int do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt,
831 unsigned size)
832 {
833 unsigned done_size = ctxt->fetch.end - ctxt->fetch.ptr;
834
835 if (unlikely(done_size < size))
836 return __do_insn_fetch_bytes(ctxt, size - done_size);
837 else
838 return X86EMUL_CONTINUE;
839 }
840
841 /* Fetch next part of the instruction being emulated. */
842 #define insn_fetch(_type, _ctxt) \
843 ({ _type _x; \
844 \
845 rc = do_insn_fetch_bytes(_ctxt, sizeof(_type)); \
846 if (rc != X86EMUL_CONTINUE) \
847 goto done; \
848 ctxt->_eip += sizeof(_type); \
849 _x = *(_type __aligned(1) *) ctxt->fetch.ptr; \
850 ctxt->fetch.ptr += sizeof(_type); \
851 _x; \
852 })
853
854 #define insn_fetch_arr(_arr, _size, _ctxt) \
855 ({ \
856 rc = do_insn_fetch_bytes(_ctxt, _size); \
857 if (rc != X86EMUL_CONTINUE) \
858 goto done; \
859 ctxt->_eip += (_size); \
860 memcpy(_arr, ctxt->fetch.ptr, _size); \
861 ctxt->fetch.ptr += (_size); \
862 })
863
864 /*
865 * Given the 'reg' portion of a ModRM byte, and a register block, return a
866 * pointer into the block that addresses the relevant register.
867 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
868 */
869 static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg,
870 int byteop)
871 {
872 void *p;
873 int highbyte_regs = (ctxt->rex_prefix == 0) && byteop;
874
875 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
876 p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1;
877 else
878 p = reg_rmw(ctxt, modrm_reg);
879 return p;
880 }
881
882 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
883 struct segmented_address addr,
884 u16 *size, unsigned long *address, int op_bytes)
885 {
886 int rc;
887
888 if (op_bytes == 2)
889 op_bytes = 3;
890 *address = 0;
891 rc = segmented_read_std(ctxt, addr, size, 2);
892 if (rc != X86EMUL_CONTINUE)
893 return rc;
894 addr.ea += 2;
895 rc = segmented_read_std(ctxt, addr, address, op_bytes);
896 return rc;
897 }
898
899 FASTOP2(add);
900 FASTOP2(or);
901 FASTOP2(adc);
902 FASTOP2(sbb);
903 FASTOP2(and);
904 FASTOP2(sub);
905 FASTOP2(xor);
906 FASTOP2(cmp);
907 FASTOP2(test);
908
909 FASTOP1SRC2(mul, mul_ex);
910 FASTOP1SRC2(imul, imul_ex);
911 FASTOP1SRC2EX(div, div_ex);
912 FASTOP1SRC2EX(idiv, idiv_ex);
913
914 FASTOP3WCL(shld);
915 FASTOP3WCL(shrd);
916
917 FASTOP2W(imul);
918
919 FASTOP1(not);
920 FASTOP1(neg);
921 FASTOP1(inc);
922 FASTOP1(dec);
923
924 FASTOP2CL(rol);
925 FASTOP2CL(ror);
926 FASTOP2CL(rcl);
927 FASTOP2CL(rcr);
928 FASTOP2CL(shl);
929 FASTOP2CL(shr);
930 FASTOP2CL(sar);
931
932 FASTOP2W(bsf);
933 FASTOP2W(bsr);
934 FASTOP2W(bt);
935 FASTOP2W(bts);
936 FASTOP2W(btr);
937 FASTOP2W(btc);
938
939 FASTOP2(xadd);
940
941 FASTOP2R(cmp, cmp_r);
942
943 static int em_bsf_c(struct x86_emulate_ctxt *ctxt)
944 {
945 /* If src is zero, do not writeback, but update flags */
946 if (ctxt->src.val == 0)
947 ctxt->dst.type = OP_NONE;
948 return fastop(ctxt, em_bsf);
949 }
950
951 static int em_bsr_c(struct x86_emulate_ctxt *ctxt)
952 {
953 /* If src is zero, do not writeback, but update flags */
954 if (ctxt->src.val == 0)
955 ctxt->dst.type = OP_NONE;
956 return fastop(ctxt, em_bsr);
957 }
958
959 static u8 test_cc(unsigned int condition, unsigned long flags)
960 {
961 u8 rc;
962 void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
963
964 flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
965 asm("push %[flags]; popf; call *%[fastop]"
966 : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags));
967 return rc;
968 }
969
970 static void fetch_register_operand(struct operand *op)
971 {
972 switch (op->bytes) {
973 case 1:
974 op->val = *(u8 *)op->addr.reg;
975 break;
976 case 2:
977 op->val = *(u16 *)op->addr.reg;
978 break;
979 case 4:
980 op->val = *(u32 *)op->addr.reg;
981 break;
982 case 8:
983 op->val = *(u64 *)op->addr.reg;
984 break;
985 }
986 }
987
988 static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
989 {
990 ctxt->ops->get_fpu(ctxt);
991 switch (reg) {
992 case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break;
993 case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break;
994 case 2: asm("movdqa %%xmm2, %0" : "=m"(*data)); break;
995 case 3: asm("movdqa %%xmm3, %0" : "=m"(*data)); break;
996 case 4: asm("movdqa %%xmm4, %0" : "=m"(*data)); break;
997 case 5: asm("movdqa %%xmm5, %0" : "=m"(*data)); break;
998 case 6: asm("movdqa %%xmm6, %0" : "=m"(*data)); break;
999 case 7: asm("movdqa %%xmm7, %0" : "=m"(*data)); break;
1000 #ifdef CONFIG_X86_64
1001 case 8: asm("movdqa %%xmm8, %0" : "=m"(*data)); break;
1002 case 9: asm("movdqa %%xmm9, %0" : "=m"(*data)); break;
1003 case 10: asm("movdqa %%xmm10, %0" : "=m"(*data)); break;
1004 case 11: asm("movdqa %%xmm11, %0" : "=m"(*data)); break;
1005 case 12: asm("movdqa %%xmm12, %0" : "=m"(*data)); break;
1006 case 13: asm("movdqa %%xmm13, %0" : "=m"(*data)); break;
1007 case 14: asm("movdqa %%xmm14, %0" : "=m"(*data)); break;
1008 case 15: asm("movdqa %%xmm15, %0" : "=m"(*data)); break;
1009 #endif
1010 default: BUG();
1011 }
1012 ctxt->ops->put_fpu(ctxt);
1013 }
1014
1015 static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
1016 int reg)
1017 {
1018 ctxt->ops->get_fpu(ctxt);
1019 switch (reg) {
1020 case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break;
1021 case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break;
1022 case 2: asm("movdqa %0, %%xmm2" : : "m"(*data)); break;
1023 case 3: asm("movdqa %0, %%xmm3" : : "m"(*data)); break;
1024 case 4: asm("movdqa %0, %%xmm4" : : "m"(*data)); break;
1025 case 5: asm("movdqa %0, %%xmm5" : : "m"(*data)); break;
1026 case 6: asm("movdqa %0, %%xmm6" : : "m"(*data)); break;
1027 case 7: asm("movdqa %0, %%xmm7" : : "m"(*data)); break;
1028 #ifdef CONFIG_X86_64
1029 case 8: asm("movdqa %0, %%xmm8" : : "m"(*data)); break;
1030 case 9: asm("movdqa %0, %%xmm9" : : "m"(*data)); break;
1031 case 10: asm("movdqa %0, %%xmm10" : : "m"(*data)); break;
1032 case 11: asm("movdqa %0, %%xmm11" : : "m"(*data)); break;
1033 case 12: asm("movdqa %0, %%xmm12" : : "m"(*data)); break;
1034 case 13: asm("movdqa %0, %%xmm13" : : "m"(*data)); break;
1035 case 14: asm("movdqa %0, %%xmm14" : : "m"(*data)); break;
1036 case 15: asm("movdqa %0, %%xmm15" : : "m"(*data)); break;
1037 #endif
1038 default: BUG();
1039 }
1040 ctxt->ops->put_fpu(ctxt);
1041 }
1042
1043 static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
1044 {
1045 ctxt->ops->get_fpu(ctxt);
1046 switch (reg) {
1047 case 0: asm("movq %%mm0, %0" : "=m"(*data)); break;
1048 case 1: asm("movq %%mm1, %0" : "=m"(*data)); break;
1049 case 2: asm("movq %%mm2, %0" : "=m"(*data)); break;
1050 case 3: asm("movq %%mm3, %0" : "=m"(*data)); break;
1051 case 4: asm("movq %%mm4, %0" : "=m"(*data)); break;
1052 case 5: asm("movq %%mm5, %0" : "=m"(*data)); break;
1053 case 6: asm("movq %%mm6, %0" : "=m"(*data)); break;
1054 case 7: asm("movq %%mm7, %0" : "=m"(*data)); break;
1055 default: BUG();
1056 }
1057 ctxt->ops->put_fpu(ctxt);
1058 }
1059
1060 static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
1061 {
1062 ctxt->ops->get_fpu(ctxt);
1063 switch (reg) {
1064 case 0: asm("movq %0, %%mm0" : : "m"(*data)); break;
1065 case 1: asm("movq %0, %%mm1" : : "m"(*data)); break;
1066 case 2: asm("movq %0, %%mm2" : : "m"(*data)); break;
1067 case 3: asm("movq %0, %%mm3" : : "m"(*data)); break;
1068 case 4: asm("movq %0, %%mm4" : : "m"(*data)); break;
1069 case 5: asm("movq %0, %%mm5" : : "m"(*data)); break;
1070 case 6: asm("movq %0, %%mm6" : : "m"(*data)); break;
1071 case 7: asm("movq %0, %%mm7" : : "m"(*data)); break;
1072 default: BUG();
1073 }
1074 ctxt->ops->put_fpu(ctxt);
1075 }
1076
1077 static int em_fninit(struct x86_emulate_ctxt *ctxt)
1078 {
1079 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1080 return emulate_nm(ctxt);
1081
1082 ctxt->ops->get_fpu(ctxt);
1083 asm volatile("fninit");
1084 ctxt->ops->put_fpu(ctxt);
1085 return X86EMUL_CONTINUE;
1086 }
1087
1088 static int em_fnstcw(struct x86_emulate_ctxt *ctxt)
1089 {
1090 u16 fcw;
1091
1092 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1093 return emulate_nm(ctxt);
1094
1095 ctxt->ops->get_fpu(ctxt);
1096 asm volatile("fnstcw %0": "+m"(fcw));
1097 ctxt->ops->put_fpu(ctxt);
1098
1099 ctxt->dst.val = fcw;
1100
1101 return X86EMUL_CONTINUE;
1102 }
1103
1104 static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
1105 {
1106 u16 fsw;
1107
1108 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1109 return emulate_nm(ctxt);
1110
1111 ctxt->ops->get_fpu(ctxt);
1112 asm volatile("fnstsw %0": "+m"(fsw));
1113 ctxt->ops->put_fpu(ctxt);
1114
1115 ctxt->dst.val = fsw;
1116
1117 return X86EMUL_CONTINUE;
1118 }
1119
1120 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
1121 struct operand *op)
1122 {
1123 unsigned reg = ctxt->modrm_reg;
1124
1125 if (!(ctxt->d & ModRM))
1126 reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3);
1127
1128 if (ctxt->d & Sse) {
1129 op->type = OP_XMM;
1130 op->bytes = 16;
1131 op->addr.xmm = reg;
1132 read_sse_reg(ctxt, &op->vec_val, reg);
1133 return;
1134 }
1135 if (ctxt->d & Mmx) {
1136 reg &= 7;
1137 op->type = OP_MM;
1138 op->bytes = 8;
1139 op->addr.mm = reg;
1140 return;
1141 }
1142
1143 op->type = OP_REG;
1144 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
1145 op->addr.reg = decode_register(ctxt, reg, ctxt->d & ByteOp);
1146
1147 fetch_register_operand(op);
1148 op->orig_val = op->val;
1149 }
1150
1151 static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg)
1152 {
1153 if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP)
1154 ctxt->modrm_seg = VCPU_SREG_SS;
1155 }
1156
1157 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
1158 struct operand *op)
1159 {
1160 u8 sib;
1161 int index_reg, base_reg, scale;
1162 int rc = X86EMUL_CONTINUE;
1163 ulong modrm_ea = 0;
1164
1165 ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8); /* REX.R */
1166 index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */
1167 base_reg = (ctxt->rex_prefix << 3) & 8; /* REX.B */
1168
1169 ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6;
1170 ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3;
1171 ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07);
1172 ctxt->modrm_seg = VCPU_SREG_DS;
1173
1174 if (ctxt->modrm_mod == 3 || (ctxt->d & NoMod)) {
1175 op->type = OP_REG;
1176 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
1177 op->addr.reg = decode_register(ctxt, ctxt->modrm_rm,
1178 ctxt->d & ByteOp);
1179 if (ctxt->d & Sse) {
1180 op->type = OP_XMM;
1181 op->bytes = 16;
1182 op->addr.xmm = ctxt->modrm_rm;
1183 read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
1184 return rc;
1185 }
1186 if (ctxt->d & Mmx) {
1187 op->type = OP_MM;
1188 op->bytes = 8;
1189 op->addr.mm = ctxt->modrm_rm & 7;
1190 return rc;
1191 }
1192 fetch_register_operand(op);
1193 return rc;
1194 }
1195
1196 op->type = OP_MEM;
1197
1198 if (ctxt->ad_bytes == 2) {
1199 unsigned bx = reg_read(ctxt, VCPU_REGS_RBX);
1200 unsigned bp = reg_read(ctxt, VCPU_REGS_RBP);
1201 unsigned si = reg_read(ctxt, VCPU_REGS_RSI);
1202 unsigned di = reg_read(ctxt, VCPU_REGS_RDI);
1203
1204 /* 16-bit ModR/M decode. */
1205 switch (ctxt->modrm_mod) {
1206 case 0:
1207 if (ctxt->modrm_rm == 6)
1208 modrm_ea += insn_fetch(u16, ctxt);
1209 break;
1210 case 1:
1211 modrm_ea += insn_fetch(s8, ctxt);
1212 break;
1213 case 2:
1214 modrm_ea += insn_fetch(u16, ctxt);
1215 break;
1216 }
1217 switch (ctxt->modrm_rm) {
1218 case 0:
1219 modrm_ea += bx + si;
1220 break;
1221 case 1:
1222 modrm_ea += bx + di;
1223 break;
1224 case 2:
1225 modrm_ea += bp + si;
1226 break;
1227 case 3:
1228 modrm_ea += bp + di;
1229 break;
1230 case 4:
1231 modrm_ea += si;
1232 break;
1233 case 5:
1234 modrm_ea += di;
1235 break;
1236 case 6:
1237 if (ctxt->modrm_mod != 0)
1238 modrm_ea += bp;
1239 break;
1240 case 7:
1241 modrm_ea += bx;
1242 break;
1243 }
1244 if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 ||
1245 (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0))
1246 ctxt->modrm_seg = VCPU_SREG_SS;
1247 modrm_ea = (u16)modrm_ea;
1248 } else {
1249 /* 32/64-bit ModR/M decode. */
1250 if ((ctxt->modrm_rm & 7) == 4) {
1251 sib = insn_fetch(u8, ctxt);
1252 index_reg |= (sib >> 3) & 7;
1253 base_reg |= sib & 7;
1254 scale = sib >> 6;
1255
1256 if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0)
1257 modrm_ea += insn_fetch(s32, ctxt);
1258 else {
1259 modrm_ea += reg_read(ctxt, base_reg);
1260 adjust_modrm_seg(ctxt, base_reg);
1261 /* Increment ESP on POP [ESP] */
1262 if ((ctxt->d & IncSP) &&
1263 base_reg == VCPU_REGS_RSP)
1264 modrm_ea += ctxt->op_bytes;
1265 }
1266 if (index_reg != 4)
1267 modrm_ea += reg_read(ctxt, index_reg) << scale;
1268 } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) {
1269 modrm_ea += insn_fetch(s32, ctxt);
1270 if (ctxt->mode == X86EMUL_MODE_PROT64)
1271 ctxt->rip_relative = 1;
1272 } else {
1273 base_reg = ctxt->modrm_rm;
1274 modrm_ea += reg_read(ctxt, base_reg);
1275 adjust_modrm_seg(ctxt, base_reg);
1276 }
1277 switch (ctxt->modrm_mod) {
1278 case 1:
1279 modrm_ea += insn_fetch(s8, ctxt);
1280 break;
1281 case 2:
1282 modrm_ea += insn_fetch(s32, ctxt);
1283 break;
1284 }
1285 }
1286 op->addr.mem.ea = modrm_ea;
1287 if (ctxt->ad_bytes != 8)
1288 ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
1289
1290 done:
1291 return rc;
1292 }
1293
1294 static int decode_abs(struct x86_emulate_ctxt *ctxt,
1295 struct operand *op)
1296 {
1297 int rc = X86EMUL_CONTINUE;
1298
1299 op->type = OP_MEM;
1300 switch (ctxt->ad_bytes) {
1301 case 2:
1302 op->addr.mem.ea = insn_fetch(u16, ctxt);
1303 break;
1304 case 4:
1305 op->addr.mem.ea = insn_fetch(u32, ctxt);
1306 break;
1307 case 8:
1308 op->addr.mem.ea = insn_fetch(u64, ctxt);
1309 break;
1310 }
1311 done:
1312 return rc;
1313 }
1314
1315 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt)
1316 {
1317 long sv = 0, mask;
1318
1319 if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) {
1320 mask = ~((long)ctxt->dst.bytes * 8 - 1);
1321
1322 if (ctxt->src.bytes == 2)
1323 sv = (s16)ctxt->src.val & (s16)mask;
1324 else if (ctxt->src.bytes == 4)
1325 sv = (s32)ctxt->src.val & (s32)mask;
1326 else
1327 sv = (s64)ctxt->src.val & (s64)mask;
1328
1329 ctxt->dst.addr.mem.ea = address_mask(ctxt,
1330 ctxt->dst.addr.mem.ea + (sv >> 3));
1331 }
1332
1333 /* only subword offset */
1334 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
1335 }
1336
1337 static int read_emulated(struct x86_emulate_ctxt *ctxt,
1338 unsigned long addr, void *dest, unsigned size)
1339 {
1340 int rc;
1341 struct read_cache *mc = &ctxt->mem_read;
1342
1343 if (mc->pos < mc->end)
1344 goto read_cached;
1345
1346 WARN_ON((mc->end + size) >= sizeof(mc->data));
1347
1348 rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size,
1349 &ctxt->exception);
1350 if (rc != X86EMUL_CONTINUE)
1351 return rc;
1352
1353 mc->end += size;
1354
1355 read_cached:
1356 memcpy(dest, mc->data + mc->pos, size);
1357 mc->pos += size;
1358 return X86EMUL_CONTINUE;
1359 }
1360
1361 static int segmented_read(struct x86_emulate_ctxt *ctxt,
1362 struct segmented_address addr,
1363 void *data,
1364 unsigned size)
1365 {
1366 int rc;
1367 ulong linear;
1368
1369 rc = linearize(ctxt, addr, size, false, &linear);
1370 if (rc != X86EMUL_CONTINUE)
1371 return rc;
1372 return read_emulated(ctxt, linear, data, size);
1373 }
1374
1375 static int segmented_write(struct x86_emulate_ctxt *ctxt,
1376 struct segmented_address addr,
1377 const void *data,
1378 unsigned size)
1379 {
1380 int rc;
1381 ulong linear;
1382
1383 rc = linearize(ctxt, addr, size, true, &linear);
1384 if (rc != X86EMUL_CONTINUE)
1385 return rc;
1386 return ctxt->ops->write_emulated(ctxt, linear, data, size,
1387 &ctxt->exception);
1388 }
1389
1390 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
1391 struct segmented_address addr,
1392 const void *orig_data, const void *data,
1393 unsigned size)
1394 {
1395 int rc;
1396 ulong linear;
1397
1398 rc = linearize(ctxt, addr, size, true, &linear);
1399 if (rc != X86EMUL_CONTINUE)
1400 return rc;
1401 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data,
1402 size, &ctxt->exception);
1403 }
1404
1405 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
1406 unsigned int size, unsigned short port,
1407 void *dest)
1408 {
1409 struct read_cache *rc = &ctxt->io_read;
1410
1411 if (rc->pos == rc->end) { /* refill pio read ahead */
1412 unsigned int in_page, n;
1413 unsigned int count = ctxt->rep_prefix ?
1414 address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1;
1415 in_page = (ctxt->eflags & X86_EFLAGS_DF) ?
1416 offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) :
1417 PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI));
1418 n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count);
1419 if (n == 0)
1420 n = 1;
1421 rc->pos = rc->end = 0;
1422 if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n))
1423 return 0;
1424 rc->end = n * size;
1425 }
1426
1427 if (ctxt->rep_prefix && (ctxt->d & String) &&
1428 !(ctxt->eflags & X86_EFLAGS_DF)) {
1429 ctxt->dst.data = rc->data + rc->pos;
1430 ctxt->dst.type = OP_MEM_STR;
1431 ctxt->dst.count = (rc->end - rc->pos) / size;
1432 rc->pos = rc->end;
1433 } else {
1434 memcpy(dest, rc->data + rc->pos, size);
1435 rc->pos += size;
1436 }
1437 return 1;
1438 }
1439
1440 static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt,
1441 u16 index, struct desc_struct *desc)
1442 {
1443 struct desc_ptr dt;
1444 ulong addr;
1445
1446 ctxt->ops->get_idt(ctxt, &dt);
1447
1448 if (dt.size < index * 8 + 7)
1449 return emulate_gp(ctxt, index << 3 | 0x2);
1450
1451 addr = dt.address + index * 8;
1452 return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1453 &ctxt->exception);
1454 }
1455
1456 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
1457 u16 selector, struct desc_ptr *dt)
1458 {
1459 const struct x86_emulate_ops *ops = ctxt->ops;
1460 u32 base3 = 0;
1461
1462 if (selector & 1 << 2) {
1463 struct desc_struct desc;
1464 u16 sel;
1465
1466 memset (dt, 0, sizeof *dt);
1467 if (!ops->get_segment(ctxt, &sel, &desc, &base3,
1468 VCPU_SREG_LDTR))
1469 return;
1470
1471 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
1472 dt->address = get_desc_base(&desc) | ((u64)base3 << 32);
1473 } else
1474 ops->get_gdt(ctxt, dt);
1475 }
1476
1477 static int get_descriptor_ptr(struct x86_emulate_ctxt *ctxt,
1478 u16 selector, ulong *desc_addr_p)
1479 {
1480 struct desc_ptr dt;
1481 u16 index = selector >> 3;
1482 ulong addr;
1483
1484 get_descriptor_table_ptr(ctxt, selector, &dt);
1485
1486 if (dt.size < index * 8 + 7)
1487 return emulate_gp(ctxt, selector & 0xfffc);
1488
1489 addr = dt.address + index * 8;
1490
1491 #ifdef CONFIG_X86_64
1492 if (addr >> 32 != 0) {
1493 u64 efer = 0;
1494
1495 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
1496 if (!(efer & EFER_LMA))
1497 addr &= (u32)-1;
1498 }
1499 #endif
1500
1501 *desc_addr_p = addr;
1502 return X86EMUL_CONTINUE;
1503 }
1504
1505 /* allowed just for 8 bytes segments */
1506 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1507 u16 selector, struct desc_struct *desc,
1508 ulong *desc_addr_p)
1509 {
1510 int rc;
1511
1512 rc = get_descriptor_ptr(ctxt, selector, desc_addr_p);
1513 if (rc != X86EMUL_CONTINUE)
1514 return rc;
1515
1516 return ctxt->ops->read_std(ctxt, *desc_addr_p, desc, sizeof(*desc),
1517 &ctxt->exception);
1518 }
1519
1520 /* allowed just for 8 bytes segments */
1521 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1522 u16 selector, struct desc_struct *desc)
1523 {
1524 int rc;
1525 ulong addr;
1526
1527 rc = get_descriptor_ptr(ctxt, selector, &addr);
1528 if (rc != X86EMUL_CONTINUE)
1529 return rc;
1530
1531 return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,
1532 &ctxt->exception);
1533 }
1534
1535 /* Does not support long mode */
1536 static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1537 u16 selector, int seg, u8 cpl,
1538 enum x86_transfer_type transfer,
1539 struct desc_struct *desc)
1540 {
1541 struct desc_struct seg_desc, old_desc;
1542 u8 dpl, rpl;
1543 unsigned err_vec = GP_VECTOR;
1544 u32 err_code = 0;
1545 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
1546 ulong desc_addr;
1547 int ret;
1548 u16 dummy;
1549 u32 base3 = 0;
1550
1551 memset(&seg_desc, 0, sizeof seg_desc);
1552
1553 if (ctxt->mode == X86EMUL_MODE_REAL) {
1554 /* set real mode segment descriptor (keep limit etc. for
1555 * unreal mode) */
1556 ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg);
1557 set_desc_base(&seg_desc, selector << 4);
1558 goto load;
1559 } else if (seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) {
1560 /* VM86 needs a clean new segment descriptor */
1561 set_desc_base(&seg_desc, selector << 4);
1562 set_desc_limit(&seg_desc, 0xffff);
1563 seg_desc.type = 3;
1564 seg_desc.p = 1;
1565 seg_desc.s = 1;
1566 seg_desc.dpl = 3;
1567 goto load;
1568 }
1569
1570 rpl = selector & 3;
1571
1572 /* NULL selector is not valid for TR, CS and SS (except for long mode) */
1573 if ((seg == VCPU_SREG_CS
1574 || (seg == VCPU_SREG_SS
1575 && (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl))
1576 || seg == VCPU_SREG_TR)
1577 && null_selector)
1578 goto exception;
1579
1580 /* TR should be in GDT only */
1581 if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
1582 goto exception;
1583
1584 if (null_selector) /* for NULL selector skip all following checks */
1585 goto load;
1586
1587 ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr);
1588 if (ret != X86EMUL_CONTINUE)
1589 return ret;
1590
1591 err_code = selector & 0xfffc;
1592 err_vec = (transfer == X86_TRANSFER_TASK_SWITCH) ? TS_VECTOR :
1593 GP_VECTOR;
1594
1595 /* can't load system descriptor into segment selector */
1596 if (seg <= VCPU_SREG_GS && !seg_desc.s) {
1597 if (transfer == X86_TRANSFER_CALL_JMP)
1598 return X86EMUL_UNHANDLEABLE;
1599 goto exception;
1600 }
1601
1602 if (!seg_desc.p) {
1603 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
1604 goto exception;
1605 }
1606
1607 dpl = seg_desc.dpl;
1608
1609 switch (seg) {
1610 case VCPU_SREG_SS:
1611 /*
1612 * segment is not a writable data segment or segment
1613 * selector's RPL != CPL or segment selector's RPL != CPL
1614 */
1615 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
1616 goto exception;
1617 break;
1618 case VCPU_SREG_CS:
1619 if (!(seg_desc.type & 8))
1620 goto exception;
1621
1622 if (seg_desc.type & 4) {
1623 /* conforming */
1624 if (dpl > cpl)
1625 goto exception;
1626 } else {
1627 /* nonconforming */
1628 if (rpl > cpl || dpl != cpl)
1629 goto exception;
1630 }
1631 /* in long-mode d/b must be clear if l is set */
1632 if (seg_desc.d && seg_desc.l) {
1633 u64 efer = 0;
1634
1635 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
1636 if (efer & EFER_LMA)
1637 goto exception;
1638 }
1639
1640 /* CS(RPL) <- CPL */
1641 selector = (selector & 0xfffc) | cpl;
1642 break;
1643 case VCPU_SREG_TR:
1644 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1645 goto exception;
1646 old_desc = seg_desc;
1647 seg_desc.type |= 2; /* busy */
1648 ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc,
1649 sizeof(seg_desc), &ctxt->exception);
1650 if (ret != X86EMUL_CONTINUE)
1651 return ret;
1652 break;
1653 case VCPU_SREG_LDTR:
1654 if (seg_desc.s || seg_desc.type != 2)
1655 goto exception;
1656 break;
1657 default: /* DS, ES, FS, or GS */
1658 /*
1659 * segment is not a data or readable code segment or
1660 * ((segment is a data or nonconforming code segment)
1661 * and (both RPL and CPL > DPL))
1662 */
1663 if ((seg_desc.type & 0xa) == 0x8 ||
1664 (((seg_desc.type & 0xc) != 0xc) &&
1665 (rpl > dpl && cpl > dpl)))
1666 goto exception;
1667 break;
1668 }
1669
1670 if (seg_desc.s) {
1671 /* mark segment as accessed */
1672 if (!(seg_desc.type & 1)) {
1673 seg_desc.type |= 1;
1674 ret = write_segment_descriptor(ctxt, selector,
1675 &seg_desc);
1676 if (ret != X86EMUL_CONTINUE)
1677 return ret;
1678 }
1679 } else if (ctxt->mode == X86EMUL_MODE_PROT64) {
1680 ret = ctxt->ops->read_std(ctxt, desc_addr+8, &base3,
1681 sizeof(base3), &ctxt->exception);
1682 if (ret != X86EMUL_CONTINUE)
1683 return ret;
1684 if (is_noncanonical_address(get_desc_base(&seg_desc) |
1685 ((u64)base3 << 32)))
1686 return emulate_gp(ctxt, 0);
1687 }
1688 load:
1689 ctxt->ops->set_segment(ctxt, selector, &seg_desc, base3, seg);
1690 if (desc)
1691 *desc = seg_desc;
1692 return X86EMUL_CONTINUE;
1693 exception:
1694 return emulate_exception(ctxt, err_vec, err_code, true);
1695 }
1696
1697 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1698 u16 selector, int seg)
1699 {
1700 u8 cpl = ctxt->ops->cpl(ctxt);
1701 return __load_segment_descriptor(ctxt, selector, seg, cpl,
1702 X86_TRANSFER_NONE, NULL);
1703 }
1704
1705 static void write_register_operand(struct operand *op)
1706 {
1707 return assign_register(op->addr.reg, op->val, op->bytes);
1708 }
1709
1710 static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op)
1711 {
1712 switch (op->type) {
1713 case OP_REG:
1714 write_register_operand(op);
1715 break;
1716 case OP_MEM:
1717 if (ctxt->lock_prefix)
1718 return segmented_cmpxchg(ctxt,
1719 op->addr.mem,
1720 &op->orig_val,
1721 &op->val,
1722 op->bytes);
1723 else
1724 return segmented_write(ctxt,
1725 op->addr.mem,
1726 &op->val,
1727 op->bytes);
1728 break;
1729 case OP_MEM_STR:
1730 return segmented_write(ctxt,
1731 op->addr.mem,
1732 op->data,
1733 op->bytes * op->count);
1734 break;
1735 case OP_XMM:
1736 write_sse_reg(ctxt, &op->vec_val, op->addr.xmm);
1737 break;
1738 case OP_MM:
1739 write_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
1740 break;
1741 case OP_NONE:
1742 /* no writeback */
1743 break;
1744 default:
1745 break;
1746 }
1747 return X86EMUL_CONTINUE;
1748 }
1749
1750 static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes)
1751 {
1752 struct segmented_address addr;
1753
1754 rsp_increment(ctxt, -bytes);
1755 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt);
1756 addr.seg = VCPU_SREG_SS;
1757
1758 return segmented_write(ctxt, addr, data, bytes);
1759 }
1760
1761 static int em_push(struct x86_emulate_ctxt *ctxt)
1762 {
1763 /* Disable writeback. */
1764 ctxt->dst.type = OP_NONE;
1765 return push(ctxt, &ctxt->src.val, ctxt->op_bytes);
1766 }
1767
1768 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1769 void *dest, int len)
1770 {
1771 int rc;
1772 struct segmented_address addr;
1773
1774 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt);
1775 addr.seg = VCPU_SREG_SS;
1776 rc = segmented_read(ctxt, addr, dest, len);
1777 if (rc != X86EMUL_CONTINUE)
1778 return rc;
1779
1780 rsp_increment(ctxt, len);
1781 return rc;
1782 }
1783
1784 static int em_pop(struct x86_emulate_ctxt *ctxt)
1785 {
1786 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1787 }
1788
1789 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1790 void *dest, int len)
1791 {
1792 int rc;
1793 unsigned long val, change_mask;
1794 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT;
1795 int cpl = ctxt->ops->cpl(ctxt);
1796
1797 rc = emulate_pop(ctxt, &val, len);
1798 if (rc != X86EMUL_CONTINUE)
1799 return rc;
1800
1801 change_mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF |
1802 X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_OF |
1803 X86_EFLAGS_TF | X86_EFLAGS_DF | X86_EFLAGS_NT |
1804 X86_EFLAGS_AC | X86_EFLAGS_ID;
1805
1806 switch(ctxt->mode) {
1807 case X86EMUL_MODE_PROT64:
1808 case X86EMUL_MODE_PROT32:
1809 case X86EMUL_MODE_PROT16:
1810 if (cpl == 0)
1811 change_mask |= X86_EFLAGS_IOPL;
1812 if (cpl <= iopl)
1813 change_mask |= X86_EFLAGS_IF;
1814 break;
1815 case X86EMUL_MODE_VM86:
1816 if (iopl < 3)
1817 return emulate_gp(ctxt, 0);
1818 change_mask |= X86_EFLAGS_IF;
1819 break;
1820 default: /* real mode */
1821 change_mask |= (X86_EFLAGS_IOPL | X86_EFLAGS_IF);
1822 break;
1823 }
1824
1825 *(unsigned long *)dest =
1826 (ctxt->eflags & ~change_mask) | (val & change_mask);
1827
1828 return rc;
1829 }
1830
1831 static int em_popf(struct x86_emulate_ctxt *ctxt)
1832 {
1833 ctxt->dst.type = OP_REG;
1834 ctxt->dst.addr.reg = &ctxt->eflags;
1835 ctxt->dst.bytes = ctxt->op_bytes;
1836 return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1837 }
1838
1839 static int em_enter(struct x86_emulate_ctxt *ctxt)
1840 {
1841 int rc;
1842 unsigned frame_size = ctxt->src.val;
1843 unsigned nesting_level = ctxt->src2.val & 31;
1844 ulong rbp;
1845
1846 if (nesting_level)
1847 return X86EMUL_UNHANDLEABLE;
1848
1849 rbp = reg_read(ctxt, VCPU_REGS_RBP);
1850 rc = push(ctxt, &rbp, stack_size(ctxt));
1851 if (rc != X86EMUL_CONTINUE)
1852 return rc;
1853 assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP),
1854 stack_mask(ctxt));
1855 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP),
1856 reg_read(ctxt, VCPU_REGS_RSP) - frame_size,
1857 stack_mask(ctxt));
1858 return X86EMUL_CONTINUE;
1859 }
1860
1861 static int em_leave(struct x86_emulate_ctxt *ctxt)
1862 {
1863 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP),
1864 stack_mask(ctxt));
1865 return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes);
1866 }
1867
1868 static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
1869 {
1870 int seg = ctxt->src2.val;
1871
1872 ctxt->src.val = get_segment_selector(ctxt, seg);
1873 if (ctxt->op_bytes == 4) {
1874 rsp_increment(ctxt, -2);
1875 ctxt->op_bytes = 2;
1876 }
1877
1878 return em_push(ctxt);
1879 }
1880
1881 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt)
1882 {
1883 int seg = ctxt->src2.val;
1884 unsigned long selector;
1885 int rc;
1886
1887 rc = emulate_pop(ctxt, &selector, 2);
1888 if (rc != X86EMUL_CONTINUE)
1889 return rc;
1890
1891 if (ctxt->modrm_reg == VCPU_SREG_SS)
1892 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
1893 if (ctxt->op_bytes > 2)
1894 rsp_increment(ctxt, ctxt->op_bytes - 2);
1895
1896 rc = load_segment_descriptor(ctxt, (u16)selector, seg);
1897 return rc;
1898 }
1899
1900 static int em_pusha(struct x86_emulate_ctxt *ctxt)
1901 {
1902 unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP);
1903 int rc = X86EMUL_CONTINUE;
1904 int reg = VCPU_REGS_RAX;
1905
1906 while (reg <= VCPU_REGS_RDI) {
1907 (reg == VCPU_REGS_RSP) ?
1908 (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg));
1909
1910 rc = em_push(ctxt);
1911 if (rc != X86EMUL_CONTINUE)
1912 return rc;
1913
1914 ++reg;
1915 }
1916
1917 return rc;
1918 }
1919
1920 static int em_pushf(struct x86_emulate_ctxt *ctxt)
1921 {
1922 ctxt->src.val = (unsigned long)ctxt->eflags & ~X86_EFLAGS_VM;
1923 return em_push(ctxt);
1924 }
1925
1926 static int em_popa(struct x86_emulate_ctxt *ctxt)
1927 {
1928 int rc = X86EMUL_CONTINUE;
1929 int reg = VCPU_REGS_RDI;
1930 u32 val;
1931
1932 while (reg >= VCPU_REGS_RAX) {
1933 if (reg == VCPU_REGS_RSP) {
1934 rsp_increment(ctxt, ctxt->op_bytes);
1935 --reg;
1936 }
1937
1938 rc = emulate_pop(ctxt, &val, ctxt->op_bytes);
1939 if (rc != X86EMUL_CONTINUE)
1940 break;
1941 assign_register(reg_rmw(ctxt, reg), val, ctxt->op_bytes);
1942 --reg;
1943 }
1944 return rc;
1945 }
1946
1947 static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1948 {
1949 const struct x86_emulate_ops *ops = ctxt->ops;
1950 int rc;
1951 struct desc_ptr dt;
1952 gva_t cs_addr;
1953 gva_t eip_addr;
1954 u16 cs, eip;
1955
1956 /* TODO: Add limit checks */
1957 ctxt->src.val = ctxt->eflags;
1958 rc = em_push(ctxt);
1959 if (rc != X86EMUL_CONTINUE)
1960 return rc;
1961
1962 ctxt->eflags &= ~(X86_EFLAGS_IF | X86_EFLAGS_TF | X86_EFLAGS_AC);
1963
1964 ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS);
1965 rc = em_push(ctxt);
1966 if (rc != X86EMUL_CONTINUE)
1967 return rc;
1968
1969 ctxt->src.val = ctxt->_eip;
1970 rc = em_push(ctxt);
1971 if (rc != X86EMUL_CONTINUE)
1972 return rc;
1973
1974 ops->get_idt(ctxt, &dt);
1975
1976 eip_addr = dt.address + (irq << 2);
1977 cs_addr = dt.address + (irq << 2) + 2;
1978
1979 rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);
1980 if (rc != X86EMUL_CONTINUE)
1981 return rc;
1982
1983 rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);
1984 if (rc != X86EMUL_CONTINUE)
1985 return rc;
1986
1987 rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS);
1988 if (rc != X86EMUL_CONTINUE)
1989 return rc;
1990
1991 ctxt->_eip = eip;
1992
1993 return rc;
1994 }
1995
1996 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1997 {
1998 int rc;
1999
2000 invalidate_registers(ctxt);
2001 rc = __emulate_int_real(ctxt, irq);
2002 if (rc == X86EMUL_CONTINUE)
2003 writeback_registers(ctxt);
2004 return rc;
2005 }
2006
2007 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq)
2008 {
2009 switch(ctxt->mode) {
2010 case X86EMUL_MODE_REAL:
2011 return __emulate_int_real(ctxt, irq);
2012 case X86EMUL_MODE_VM86:
2013 case X86EMUL_MODE_PROT16:
2014 case X86EMUL_MODE_PROT32:
2015 case X86EMUL_MODE_PROT64:
2016 default:
2017 /* Protected mode interrupts unimplemented yet */
2018 return X86EMUL_UNHANDLEABLE;
2019 }
2020 }
2021
2022 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
2023 {
2024 int rc = X86EMUL_CONTINUE;
2025 unsigned long temp_eip = 0;
2026 unsigned long temp_eflags = 0;
2027 unsigned long cs = 0;
2028 unsigned long mask = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF |
2029 X86_EFLAGS_ZF | X86_EFLAGS_SF | X86_EFLAGS_TF |
2030 X86_EFLAGS_IF | X86_EFLAGS_DF | X86_EFLAGS_OF |
2031 X86_EFLAGS_IOPL | X86_EFLAGS_NT | X86_EFLAGS_RF |
2032 X86_EFLAGS_AC | X86_EFLAGS_ID |
2033 X86_EFLAGS_FIXED;
2034 unsigned long vm86_mask = X86_EFLAGS_VM | X86_EFLAGS_VIF |
2035 X86_EFLAGS_VIP;
2036
2037 /* TODO: Add stack limit check */
2038
2039 rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes);
2040
2041 if (rc != X86EMUL_CONTINUE)
2042 return rc;
2043
2044 if (temp_eip & ~0xffff)
2045 return emulate_gp(ctxt, 0);
2046
2047 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
2048
2049 if (rc != X86EMUL_CONTINUE)
2050 return rc;
2051
2052 rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes);
2053
2054 if (rc != X86EMUL_CONTINUE)
2055 return rc;
2056
2057 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
2058
2059 if (rc != X86EMUL_CONTINUE)
2060 return rc;
2061
2062 ctxt->_eip = temp_eip;
2063
2064 if (ctxt->op_bytes == 4)
2065 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
2066 else if (ctxt->op_bytes == 2) {
2067 ctxt->eflags &= ~0xffff;
2068 ctxt->eflags |= temp_eflags;
2069 }
2070
2071 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
2072 ctxt->eflags |= X86_EFLAGS_FIXED;
2073 ctxt->ops->set_nmi_mask(ctxt, false);
2074
2075 return rc;
2076 }
2077
2078 static int em_iret(struct x86_emulate_ctxt *ctxt)
2079 {
2080 switch(ctxt->mode) {
2081 case X86EMUL_MODE_REAL:
2082 return emulate_iret_real(ctxt);
2083 case X86EMUL_MODE_VM86:
2084 case X86EMUL_MODE_PROT16:
2085 case X86EMUL_MODE_PROT32:
2086 case X86EMUL_MODE_PROT64:
2087 default:
2088 /* iret from protected mode unimplemented yet */
2089 return X86EMUL_UNHANDLEABLE;
2090 }
2091 }
2092
2093 static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
2094 {
2095 int rc;
2096 unsigned short sel, old_sel;
2097 struct desc_struct old_desc, new_desc;
2098 const struct x86_emulate_ops *ops = ctxt->ops;
2099 u8 cpl = ctxt->ops->cpl(ctxt);
2100
2101 /* Assignment of RIP may only fail in 64-bit mode */
2102 if (ctxt->mode == X86EMUL_MODE_PROT64)
2103 ops->get_segment(ctxt, &old_sel, &old_desc, NULL,
2104 VCPU_SREG_CS);
2105
2106 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2107
2108 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl,
2109 X86_TRANSFER_CALL_JMP,
2110 &new_desc);
2111 if (rc != X86EMUL_CONTINUE)
2112 return rc;
2113
2114 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc);
2115 if (rc != X86EMUL_CONTINUE) {
2116 WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
2117 /* assigning eip failed; restore the old cs */
2118 ops->set_segment(ctxt, old_sel, &old_desc, 0, VCPU_SREG_CS);
2119 return rc;
2120 }
2121 return rc;
2122 }
2123
2124 static int em_jmp_abs(struct x86_emulate_ctxt *ctxt)
2125 {
2126 return assign_eip_near(ctxt, ctxt->src.val);
2127 }
2128
2129 static int em_call_near_abs(struct x86_emulate_ctxt *ctxt)
2130 {
2131 int rc;
2132 long int old_eip;
2133
2134 old_eip = ctxt->_eip;
2135 rc = assign_eip_near(ctxt, ctxt->src.val);
2136 if (rc != X86EMUL_CONTINUE)
2137 return rc;
2138 ctxt->src.val = old_eip;
2139 rc = em_push(ctxt);
2140 return rc;
2141 }
2142
2143 static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt)
2144 {
2145 u64 old = ctxt->dst.orig_val64;
2146
2147 if (ctxt->dst.bytes == 16)
2148 return X86EMUL_UNHANDLEABLE;
2149
2150 if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) ||
2151 ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) {
2152 *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0);
2153 *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32);
2154 ctxt->eflags &= ~X86_EFLAGS_ZF;
2155 } else {
2156 ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) |
2157 (u32) reg_read(ctxt, VCPU_REGS_RBX);
2158
2159 ctxt->eflags |= X86_EFLAGS_ZF;
2160 }
2161 return X86EMUL_CONTINUE;
2162 }
2163
2164 static int em_ret(struct x86_emulate_ctxt *ctxt)
2165 {
2166 int rc;
2167 unsigned long eip;
2168
2169 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
2170 if (rc != X86EMUL_CONTINUE)
2171 return rc;
2172
2173 return assign_eip_near(ctxt, eip);
2174 }
2175
2176 static int em_ret_far(struct x86_emulate_ctxt *ctxt)
2177 {
2178 int rc;
2179 unsigned long eip, cs;
2180 u16 old_cs;
2181 int cpl = ctxt->ops->cpl(ctxt);
2182 struct desc_struct old_desc, new_desc;
2183 const struct x86_emulate_ops *ops = ctxt->ops;
2184
2185 if (ctxt->mode == X86EMUL_MODE_PROT64)
2186 ops->get_segment(ctxt, &old_cs, &old_desc, NULL,
2187 VCPU_SREG_CS);
2188
2189 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
2190 if (rc != X86EMUL_CONTINUE)
2191 return rc;
2192 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
2193 if (rc != X86EMUL_CONTINUE)
2194 return rc;
2195 /* Outer-privilege level return is not implemented */
2196 if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl)
2197 return X86EMUL_UNHANDLEABLE;
2198 rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, cpl,
2199 X86_TRANSFER_RET,
2200 &new_desc);
2201 if (rc != X86EMUL_CONTINUE)
2202 return rc;
2203 rc = assign_eip_far(ctxt, eip, &new_desc);
2204 if (rc != X86EMUL_CONTINUE) {
2205 WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
2206 ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
2207 }
2208 return rc;
2209 }
2210
2211 static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt)
2212 {
2213 int rc;
2214
2215 rc = em_ret_far(ctxt);
2216 if (rc != X86EMUL_CONTINUE)
2217 return rc;
2218 rsp_increment(ctxt, ctxt->src.val);
2219 return X86EMUL_CONTINUE;
2220 }
2221
2222 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
2223 {
2224 /* Save real source value, then compare EAX against destination. */
2225 ctxt->dst.orig_val = ctxt->dst.val;
2226 ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX);
2227 ctxt->src.orig_val = ctxt->src.val;
2228 ctxt->src.val = ctxt->dst.orig_val;
2229 fastop(ctxt, em_cmp);
2230
2231 if (ctxt->eflags & X86_EFLAGS_ZF) {
2232 /* Success: write back to memory; no update of EAX */
2233 ctxt->src.type = OP_NONE;
2234 ctxt->dst.val = ctxt->src.orig_val;
2235 } else {
2236 /* Failure: write the value we saw to EAX. */
2237 ctxt->src.type = OP_REG;
2238 ctxt->src.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
2239 ctxt->src.val = ctxt->dst.orig_val;
2240 /* Create write-cycle to dest by writing the same value */
2241 ctxt->dst.val = ctxt->dst.orig_val;
2242 }
2243 return X86EMUL_CONTINUE;
2244 }
2245
2246 static int em_lseg(struct x86_emulate_ctxt *ctxt)
2247 {
2248 int seg = ctxt->src2.val;
2249 unsigned short sel;
2250 int rc;
2251
2252 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2253
2254 rc = load_segment_descriptor(ctxt, sel, seg);
2255 if (rc != X86EMUL_CONTINUE)
2256 return rc;
2257
2258 ctxt->dst.val = ctxt->src.val;
2259 return rc;
2260 }
2261
2262 static int emulator_has_longmode(struct x86_emulate_ctxt *ctxt)
2263 {
2264 u32 eax, ebx, ecx, edx;
2265
2266 eax = 0x80000001;
2267 ecx = 0;
2268 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2269 return edx & bit(X86_FEATURE_LM);
2270 }
2271
2272 #define GET_SMSTATE(type, smbase, offset) \
2273 ({ \
2274 type __val; \
2275 int r = ctxt->ops->read_std(ctxt, smbase + offset, &__val, \
2276 sizeof(__val), NULL); \
2277 if (r != X86EMUL_CONTINUE) \
2278 return X86EMUL_UNHANDLEABLE; \
2279 __val; \
2280 })
2281
2282 static void rsm_set_desc_flags(struct desc_struct *desc, u32 flags)
2283 {
2284 desc->g = (flags >> 23) & 1;
2285 desc->d = (flags >> 22) & 1;
2286 desc->l = (flags >> 21) & 1;
2287 desc->avl = (flags >> 20) & 1;
2288 desc->p = (flags >> 15) & 1;
2289 desc->dpl = (flags >> 13) & 3;
2290 desc->s = (flags >> 12) & 1;
2291 desc->type = (flags >> 8) & 15;
2292 }
2293
2294 static int rsm_load_seg_32(struct x86_emulate_ctxt *ctxt, u64 smbase, int n)
2295 {
2296 struct desc_struct desc;
2297 int offset;
2298 u16 selector;
2299
2300 selector = GET_SMSTATE(u32, smbase, 0x7fa8 + n * 4);
2301
2302 if (n < 3)
2303 offset = 0x7f84 + n * 12;
2304 else
2305 offset = 0x7f2c + (n - 3) * 12;
2306
2307 set_desc_base(&desc, GET_SMSTATE(u32, smbase, offset + 8));
2308 set_desc_limit(&desc, GET_SMSTATE(u32, smbase, offset + 4));
2309 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, offset));
2310 ctxt->ops->set_segment(ctxt, selector, &desc, 0, n);
2311 return X86EMUL_CONTINUE;
2312 }
2313
2314 static int rsm_load_seg_64(struct x86_emulate_ctxt *ctxt, u64 smbase, int n)
2315 {
2316 struct desc_struct desc;
2317 int offset;
2318 u16 selector;
2319 u32 base3;
2320
2321 offset = 0x7e00 + n * 16;
2322
2323 selector = GET_SMSTATE(u16, smbase, offset);
2324 rsm_set_desc_flags(&desc, GET_SMSTATE(u16, smbase, offset + 2) << 8);
2325 set_desc_limit(&desc, GET_SMSTATE(u32, smbase, offset + 4));
2326 set_desc_base(&desc, GET_SMSTATE(u32, smbase, offset + 8));
2327 base3 = GET_SMSTATE(u32, smbase, offset + 12);
2328
2329 ctxt->ops->set_segment(ctxt, selector, &desc, base3, n);
2330 return X86EMUL_CONTINUE;
2331 }
2332
2333 static int rsm_enter_protected_mode(struct x86_emulate_ctxt *ctxt,
2334 u64 cr0, u64 cr4)
2335 {
2336 int bad;
2337
2338 /*
2339 * First enable PAE, long mode needs it before CR0.PG = 1 is set.
2340 * Then enable protected mode. However, PCID cannot be enabled
2341 * if EFER.LMA=0, so set it separately.
2342 */
2343 bad = ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PCIDE);
2344 if (bad)
2345 return X86EMUL_UNHANDLEABLE;
2346
2347 bad = ctxt->ops->set_cr(ctxt, 0, cr0);
2348 if (bad)
2349 return X86EMUL_UNHANDLEABLE;
2350
2351 if (cr4 & X86_CR4_PCIDE) {
2352 bad = ctxt->ops->set_cr(ctxt, 4, cr4);
2353 if (bad)
2354 return X86EMUL_UNHANDLEABLE;
2355 }
2356
2357 return X86EMUL_CONTINUE;
2358 }
2359
2360 static int rsm_load_state_32(struct x86_emulate_ctxt *ctxt, u64 smbase)
2361 {
2362 struct desc_struct desc;
2363 struct desc_ptr dt;
2364 u16 selector;
2365 u32 val, cr0, cr4;
2366 int i;
2367
2368 cr0 = GET_SMSTATE(u32, smbase, 0x7ffc);
2369 ctxt->ops->set_cr(ctxt, 3, GET_SMSTATE(u32, smbase, 0x7ff8));
2370 ctxt->eflags = GET_SMSTATE(u32, smbase, 0x7ff4) | X86_EFLAGS_FIXED;
2371 ctxt->_eip = GET_SMSTATE(u32, smbase, 0x7ff0);
2372
2373 for (i = 0; i < 8; i++)
2374 *reg_write(ctxt, i) = GET_SMSTATE(u32, smbase, 0x7fd0 + i * 4);
2375
2376 val = GET_SMSTATE(u32, smbase, 0x7fcc);
2377 ctxt->ops->set_dr(ctxt, 6, (val & DR6_VOLATILE) | DR6_FIXED_1);
2378 val = GET_SMSTATE(u32, smbase, 0x7fc8);
2379 ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1);
2380
2381 selector = GET_SMSTATE(u32, smbase, 0x7fc4);
2382 set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7f64));
2383 set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7f60));
2384 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7f5c));
2385 ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_TR);
2386
2387 selector = GET_SMSTATE(u32, smbase, 0x7fc0);
2388 set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7f80));
2389 set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7f7c));
2390 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7f78));
2391 ctxt->ops->set_segment(ctxt, selector, &desc, 0, VCPU_SREG_LDTR);
2392
2393 dt.address = GET_SMSTATE(u32, smbase, 0x7f74);
2394 dt.size = GET_SMSTATE(u32, smbase, 0x7f70);
2395 ctxt->ops->set_gdt(ctxt, &dt);
2396
2397 dt.address = GET_SMSTATE(u32, smbase, 0x7f58);
2398 dt.size = GET_SMSTATE(u32, smbase, 0x7f54);
2399 ctxt->ops->set_idt(ctxt, &dt);
2400
2401 for (i = 0; i < 6; i++) {
2402 int r = rsm_load_seg_32(ctxt, smbase, i);
2403 if (r != X86EMUL_CONTINUE)
2404 return r;
2405 }
2406
2407 cr4 = GET_SMSTATE(u32, smbase, 0x7f14);
2408
2409 ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smbase, 0x7ef8));
2410
2411 return rsm_enter_protected_mode(ctxt, cr0, cr4);
2412 }
2413
2414 static int rsm_load_state_64(struct x86_emulate_ctxt *ctxt, u64 smbase)
2415 {
2416 struct desc_struct desc;
2417 struct desc_ptr dt;
2418 u64 val, cr0, cr4;
2419 u32 base3;
2420 u16 selector;
2421 int i, r;
2422
2423 for (i = 0; i < 16; i++)
2424 *reg_write(ctxt, i) = GET_SMSTATE(u64, smbase, 0x7ff8 - i * 8);
2425
2426 ctxt->_eip = GET_SMSTATE(u64, smbase, 0x7f78);
2427 ctxt->eflags = GET_SMSTATE(u32, smbase, 0x7f70) | X86_EFLAGS_FIXED;
2428
2429 val = GET_SMSTATE(u32, smbase, 0x7f68);
2430 ctxt->ops->set_dr(ctxt, 6, (val & DR6_VOLATILE) | DR6_FIXED_1);
2431 val = GET_SMSTATE(u32, smbase, 0x7f60);
2432 ctxt->ops->set_dr(ctxt, 7, (val & DR7_VOLATILE) | DR7_FIXED_1);
2433
2434 cr0 = GET_SMSTATE(u64, smbase, 0x7f58);
2435 ctxt->ops->set_cr(ctxt, 3, GET_SMSTATE(u64, smbase, 0x7f50));
2436 cr4 = GET_SMSTATE(u64, smbase, 0x7f48);
2437 ctxt->ops->set_smbase(ctxt, GET_SMSTATE(u32, smbase, 0x7f00));
2438 val = GET_SMSTATE(u64, smbase, 0x7ed0);
2439 ctxt->ops->set_msr(ctxt, MSR_EFER, val & ~EFER_LMA);
2440
2441 selector = GET_SMSTATE(u32, smbase, 0x7e90);
2442 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7e92) << 8);
2443 set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7e94));
2444 set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7e98));
2445 base3 = GET_SMSTATE(u32, smbase, 0x7e9c);
2446 ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_TR);
2447
2448 dt.size = GET_SMSTATE(u32, smbase, 0x7e84);
2449 dt.address = GET_SMSTATE(u64, smbase, 0x7e88);
2450 ctxt->ops->set_idt(ctxt, &dt);
2451
2452 selector = GET_SMSTATE(u32, smbase, 0x7e70);
2453 rsm_set_desc_flags(&desc, GET_SMSTATE(u32, smbase, 0x7e72) << 8);
2454 set_desc_limit(&desc, GET_SMSTATE(u32, smbase, 0x7e74));
2455 set_desc_base(&desc, GET_SMSTATE(u32, smbase, 0x7e78));
2456 base3 = GET_SMSTATE(u32, smbase, 0x7e7c);
2457 ctxt->ops->set_segment(ctxt, selector, &desc, base3, VCPU_SREG_LDTR);
2458
2459 dt.size = GET_SMSTATE(u32, smbase, 0x7e64);
2460 dt.address = GET_SMSTATE(u64, smbase, 0x7e68);
2461 ctxt->ops->set_gdt(ctxt, &dt);
2462
2463 r = rsm_enter_protected_mode(ctxt, cr0, cr4);
2464 if (r != X86EMUL_CONTINUE)
2465 return r;
2466
2467 for (i = 0; i < 6; i++) {
2468 r = rsm_load_seg_64(ctxt, smbase, i);
2469 if (r != X86EMUL_CONTINUE)
2470 return r;
2471 }
2472
2473 return X86EMUL_CONTINUE;
2474 }
2475
2476 static int em_rsm(struct x86_emulate_ctxt *ctxt)
2477 {
2478 unsigned long cr0, cr4, efer;
2479 u64 smbase;
2480 int ret;
2481
2482 if ((ctxt->emul_flags & X86EMUL_SMM_MASK) == 0)
2483 return emulate_ud(ctxt);
2484
2485 /*
2486 * Get back to real mode, to prepare a safe state in which to load
2487 * CR0/CR3/CR4/EFER. Also this will ensure that addresses passed
2488 * to read_std/write_std are not virtual.
2489 *
2490 * CR4.PCIDE must be zero, because it is a 64-bit mode only feature.
2491 */
2492 cr0 = ctxt->ops->get_cr(ctxt, 0);
2493 if (cr0 & X86_CR0_PE)
2494 ctxt->ops->set_cr(ctxt, 0, cr0 & ~(X86_CR0_PG | X86_CR0_PE));
2495 cr4 = ctxt->ops->get_cr(ctxt, 4);
2496 if (cr4 & X86_CR4_PAE)
2497 ctxt->ops->set_cr(ctxt, 4, cr4 & ~X86_CR4_PAE);
2498 efer = 0;
2499 ctxt->ops->set_msr(ctxt, MSR_EFER, efer);
2500
2501 smbase = ctxt->ops->get_smbase(ctxt);
2502 if (emulator_has_longmode(ctxt))
2503 ret = rsm_load_state_64(ctxt, smbase + 0x8000);
2504 else
2505 ret = rsm_load_state_32(ctxt, smbase + 0x8000);
2506
2507 if (ret != X86EMUL_CONTINUE) {
2508 /* FIXME: should triple fault */
2509 return X86EMUL_UNHANDLEABLE;
2510 }
2511
2512 if ((ctxt->emul_flags & X86EMUL_SMM_INSIDE_NMI_MASK) == 0)
2513 ctxt->ops->set_nmi_mask(ctxt, false);
2514
2515 ctxt->emul_flags &= ~X86EMUL_SMM_INSIDE_NMI_MASK;
2516 ctxt->emul_flags &= ~X86EMUL_SMM_MASK;
2517 return X86EMUL_CONTINUE;
2518 }
2519
2520 static void
2521 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
2522 struct desc_struct *cs, struct desc_struct *ss)
2523 {
2524 cs->l = 0; /* will be adjusted later */
2525 set_desc_base(cs, 0); /* flat segment */
2526 cs->g = 1; /* 4kb granularity */
2527 set_desc_limit(cs, 0xfffff); /* 4GB limit */
2528 cs->type = 0x0b; /* Read, Execute, Accessed */
2529 cs->s = 1;
2530 cs->dpl = 0; /* will be adjusted later */
2531 cs->p = 1;
2532 cs->d = 1;
2533 cs->avl = 0;
2534
2535 set_desc_base(ss, 0); /* flat segment */
2536 set_desc_limit(ss, 0xfffff); /* 4GB limit */
2537 ss->g = 1; /* 4kb granularity */
2538 ss->s = 1;
2539 ss->type = 0x03; /* Read/Write, Accessed */
2540 ss->d = 1; /* 32bit stack segment */
2541 ss->dpl = 0;
2542 ss->p = 1;
2543 ss->l = 0;
2544 ss->avl = 0;
2545 }
2546
2547 static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
2548 {
2549 u32 eax, ebx, ecx, edx;
2550
2551 eax = ecx = 0;
2552 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2553 return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
2554 && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
2555 && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
2556 }
2557
2558 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
2559 {
2560 const struct x86_emulate_ops *ops = ctxt->ops;
2561 u32 eax, ebx, ecx, edx;
2562
2563 /*
2564 * syscall should always be enabled in longmode - so only become
2565 * vendor specific (cpuid) if other modes are active...
2566 */
2567 if (ctxt->mode == X86EMUL_MODE_PROT64)
2568 return true;
2569
2570 eax = 0x00000000;
2571 ecx = 0x00000000;
2572 ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2573 /*
2574 * Intel ("GenuineIntel")
2575 * remark: Intel CPUs only support "syscall" in 64bit
2576 * longmode. Also an 64bit guest with a
2577 * 32bit compat-app running will #UD !! While this
2578 * behaviour can be fixed (by emulating) into AMD
2579 * response - CPUs of AMD can't behave like Intel.
2580 */
2581 if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx &&
2582 ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx &&
2583 edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx)
2584 return false;
2585
2586 /* AMD ("AuthenticAMD") */
2587 if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx &&
2588 ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx &&
2589 edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
2590 return true;
2591
2592 /* AMD ("AMDisbetter!") */
2593 if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx &&
2594 ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx &&
2595 edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
2596 return true;
2597
2598 /* default: (not Intel, not AMD), apply Intel's stricter rules... */
2599 return false;
2600 }
2601
2602 static int em_syscall(struct x86_emulate_ctxt *ctxt)
2603 {
2604 const struct x86_emulate_ops *ops = ctxt->ops;
2605 struct desc_struct cs, ss;
2606 u64 msr_data;
2607 u16 cs_sel, ss_sel;
2608 u64 efer = 0;
2609
2610 /* syscall is not available in real mode */
2611 if (ctxt->mode == X86EMUL_MODE_REAL ||
2612 ctxt->mode == X86EMUL_MODE_VM86)
2613 return emulate_ud(ctxt);
2614
2615 if (!(em_syscall_is_enabled(ctxt)))
2616 return emulate_ud(ctxt);
2617
2618 ops->get_msr(ctxt, MSR_EFER, &efer);
2619 setup_syscalls_segments(ctxt, &cs, &ss);
2620
2621 if (!(efer & EFER_SCE))
2622 return emulate_ud(ctxt);
2623
2624 ops->get_msr(ctxt, MSR_STAR, &msr_data);
2625 msr_data >>= 32;
2626 cs_sel = (u16)(msr_data & 0xfffc);
2627 ss_sel = (u16)(msr_data + 8);
2628
2629 if (efer & EFER_LMA) {
2630 cs.d = 0;
2631 cs.l = 1;
2632 }
2633 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2634 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2635
2636 *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip;
2637 if (efer & EFER_LMA) {
2638 #ifdef CONFIG_X86_64
2639 *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags;
2640
2641 ops->get_msr(ctxt,
2642 ctxt->mode == X86EMUL_MODE_PROT64 ?
2643 MSR_LSTAR : MSR_CSTAR, &msr_data);
2644 ctxt->_eip = msr_data;
2645
2646 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data);
2647 ctxt->eflags &= ~msr_data;
2648 ctxt->eflags |= X86_EFLAGS_FIXED;
2649 #endif
2650 } else {
2651 /* legacy mode */
2652 ops->get_msr(ctxt, MSR_STAR, &msr_data);
2653 ctxt->_eip = (u32)msr_data;
2654
2655 ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF);
2656 }
2657
2658 return X86EMUL_CONTINUE;
2659 }
2660
2661 static int em_sysenter(struct x86_emulate_ctxt *ctxt)
2662 {
2663 const struct x86_emulate_ops *ops = ctxt->ops;
2664 struct desc_struct cs, ss;
2665 u64 msr_data;
2666 u16 cs_sel, ss_sel;
2667 u64 efer = 0;
2668
2669 ops->get_msr(ctxt, MSR_EFER, &efer);
2670 /* inject #GP if in real mode */
2671 if (ctxt->mode == X86EMUL_MODE_REAL)
2672 return emulate_gp(ctxt, 0);
2673
2674 /*
2675 * Not recognized on AMD in compat mode (but is recognized in legacy
2676 * mode).
2677 */
2678 if ((ctxt->mode != X86EMUL_MODE_PROT64) && (efer & EFER_LMA)
2679 && !vendor_intel(ctxt))
2680 return emulate_ud(ctxt);
2681
2682 /* sysenter/sysexit have not been tested in 64bit mode. */
2683 if (ctxt->mode == X86EMUL_MODE_PROT64)
2684 return X86EMUL_UNHANDLEABLE;
2685
2686 setup_syscalls_segments(ctxt, &cs, &ss);
2687
2688 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2689 if ((msr_data & 0xfffc) == 0x0)
2690 return emulate_gp(ctxt, 0);
2691
2692 ctxt->eflags &= ~(X86_EFLAGS_VM | X86_EFLAGS_IF);
2693 cs_sel = (u16)msr_data & ~SEGMENT_RPL_MASK;
2694 ss_sel = cs_sel + 8;
2695 if (efer & EFER_LMA) {
2696 cs.d = 0;
2697 cs.l = 1;
2698 }
2699
2700 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2701 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2702
2703 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
2704 ctxt->_eip = (efer & EFER_LMA) ? msr_data : (u32)msr_data;
2705
2706 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
2707 *reg_write(ctxt, VCPU_REGS_RSP) = (efer & EFER_LMA) ? msr_data :
2708 (u32)msr_data;
2709
2710 return X86EMUL_CONTINUE;
2711 }
2712
2713 static int em_sysexit(struct x86_emulate_ctxt *ctxt)
2714 {
2715 const struct x86_emulate_ops *ops = ctxt->ops;
2716 struct desc_struct cs, ss;
2717 u64 msr_data, rcx, rdx;
2718 int usermode;
2719 u16 cs_sel = 0, ss_sel = 0;
2720
2721 /* inject #GP if in real mode or Virtual 8086 mode */
2722 if (ctxt->mode == X86EMUL_MODE_REAL ||
2723 ctxt->mode == X86EMUL_MODE_VM86)
2724 return emulate_gp(ctxt, 0);
2725
2726 setup_syscalls_segments(ctxt, &cs, &ss);
2727
2728 if ((ctxt->rex_prefix & 0x8) != 0x0)
2729 usermode = X86EMUL_MODE_PROT64;
2730 else
2731 usermode = X86EMUL_MODE_PROT32;
2732
2733 rcx = reg_read(ctxt, VCPU_REGS_RCX);
2734 rdx = reg_read(ctxt, VCPU_REGS_RDX);
2735
2736 cs.dpl = 3;
2737 ss.dpl = 3;
2738 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2739 switch (usermode) {
2740 case X86EMUL_MODE_PROT32:
2741 cs_sel = (u16)(msr_data + 16);
2742 if ((msr_data & 0xfffc) == 0x0)
2743 return emulate_gp(ctxt, 0);
2744 ss_sel = (u16)(msr_data + 24);
2745 rcx = (u32)rcx;
2746 rdx = (u32)rdx;
2747 break;
2748 case X86EMUL_MODE_PROT64:
2749 cs_sel = (u16)(msr_data + 32);
2750 if (msr_data == 0x0)
2751 return emulate_gp(ctxt, 0);
2752 ss_sel = cs_sel + 8;
2753 cs.d = 0;
2754 cs.l = 1;
2755 if (is_noncanonical_address(rcx) ||
2756 is_noncanonical_address(rdx))
2757 return emulate_gp(ctxt, 0);
2758 break;
2759 }
2760 cs_sel |= SEGMENT_RPL_MASK;
2761 ss_sel |= SEGMENT_RPL_MASK;
2762
2763 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2764 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2765
2766 ctxt->_eip = rdx;
2767 *reg_write(ctxt, VCPU_REGS_RSP) = rcx;
2768
2769 return X86EMUL_CONTINUE;
2770 }
2771
2772 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt)
2773 {
2774 int iopl;
2775 if (ctxt->mode == X86EMUL_MODE_REAL)
2776 return false;
2777 if (ctxt->mode == X86EMUL_MODE_VM86)
2778 return true;
2779 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> X86_EFLAGS_IOPL_BIT;
2780 return ctxt->ops->cpl(ctxt) > iopl;
2781 }
2782
2783 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
2784 u16 port, u16 len)
2785 {
2786 const struct x86_emulate_ops *ops = ctxt->ops;
2787 struct desc_struct tr_seg;
2788 u32 base3;
2789 int r;
2790 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7;
2791 unsigned mask = (1 << len) - 1;
2792 unsigned long base;
2793
2794 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR);
2795 if (!tr_seg.p)
2796 return false;
2797 if (desc_limit_scaled(&tr_seg) < 103)
2798 return false;
2799 base = get_desc_base(&tr_seg);
2800 #ifdef CONFIG_X86_64
2801 base |= ((u64)base3) << 32;
2802 #endif
2803 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL);
2804 if (r != X86EMUL_CONTINUE)
2805 return false;
2806 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
2807 return false;
2808 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL);
2809 if (r != X86EMUL_CONTINUE)
2810 return false;
2811 if ((perm >> bit_idx) & mask)
2812 return false;
2813 return true;
2814 }
2815
2816 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
2817 u16 port, u16 len)
2818 {
2819 if (ctxt->perm_ok)
2820 return true;
2821
2822 if (emulator_bad_iopl(ctxt))
2823 if (!emulator_io_port_access_allowed(ctxt, port, len))
2824 return false;
2825
2826 ctxt->perm_ok = true;
2827
2828 return true;
2829 }
2830
2831 static void string_registers_quirk(struct x86_emulate_ctxt *ctxt)
2832 {
2833 /*
2834 * Intel CPUs mask the counter and pointers in quite strange
2835 * manner when ECX is zero due to REP-string optimizations.
2836 */
2837 #ifdef CONFIG_X86_64
2838 if (ctxt->ad_bytes != 4 || !vendor_intel(ctxt))
2839 return;
2840
2841 *reg_write(ctxt, VCPU_REGS_RCX) = 0;
2842
2843 switch (ctxt->b) {
2844 case 0xa4: /* movsb */
2845 case 0xa5: /* movsd/w */
2846 *reg_rmw(ctxt, VCPU_REGS_RSI) &= (u32)-1;
2847 /* fall through */
2848 case 0xaa: /* stosb */
2849 case 0xab: /* stosd/w */
2850 *reg_rmw(ctxt, VCPU_REGS_RDI) &= (u32)-1;
2851 }
2852 #endif
2853 }
2854
2855 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
2856 struct tss_segment_16 *tss)
2857 {
2858 tss->ip = ctxt->_eip;
2859 tss->flag = ctxt->eflags;
2860 tss->ax = reg_read(ctxt, VCPU_REGS_RAX);
2861 tss->cx = reg_read(ctxt, VCPU_REGS_RCX);
2862 tss->dx = reg_read(ctxt, VCPU_REGS_RDX);
2863 tss->bx = reg_read(ctxt, VCPU_REGS_RBX);
2864 tss->sp = reg_read(ctxt, VCPU_REGS_RSP);
2865 tss->bp = reg_read(ctxt, VCPU_REGS_RBP);
2866 tss->si = reg_read(ctxt, VCPU_REGS_RSI);
2867 tss->di = reg_read(ctxt, VCPU_REGS_RDI);
2868
2869 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2870 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2871 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2872 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2873 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2874 }
2875
2876 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
2877 struct tss_segment_16 *tss)
2878 {
2879 int ret;
2880 u8 cpl;
2881
2882 ctxt->_eip = tss->ip;
2883 ctxt->eflags = tss->flag | 2;
2884 *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax;
2885 *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx;
2886 *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx;
2887 *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx;
2888 *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp;
2889 *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp;
2890 *reg_write(ctxt, VCPU_REGS_RSI) = tss->si;
2891 *reg_write(ctxt, VCPU_REGS_RDI) = tss->di;
2892
2893 /*
2894 * SDM says that segment selectors are loaded before segment
2895 * descriptors
2896 */
2897 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR);
2898 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2899 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2900 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2901 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2902
2903 cpl = tss->cs & 3;
2904
2905 /*
2906 * Now load segment descriptors. If fault happens at this stage
2907 * it is handled in a context of new task
2908 */
2909 ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl,
2910 X86_TRANSFER_TASK_SWITCH, NULL);
2911 if (ret != X86EMUL_CONTINUE)
2912 return ret;
2913 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl,
2914 X86_TRANSFER_TASK_SWITCH, NULL);
2915 if (ret != X86EMUL_CONTINUE)
2916 return ret;
2917 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl,
2918 X86_TRANSFER_TASK_SWITCH, NULL);
2919 if (ret != X86EMUL_CONTINUE)
2920 return ret;
2921 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl,
2922 X86_TRANSFER_TASK_SWITCH, NULL);
2923 if (ret != X86EMUL_CONTINUE)
2924 return ret;
2925 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl,
2926 X86_TRANSFER_TASK_SWITCH, NULL);
2927 if (ret != X86EMUL_CONTINUE)
2928 return ret;
2929
2930 return X86EMUL_CONTINUE;
2931 }
2932
2933 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
2934 u16 tss_selector, u16 old_tss_sel,
2935 ulong old_tss_base, struct desc_struct *new_desc)
2936 {
2937 const struct x86_emulate_ops *ops = ctxt->ops;
2938 struct tss_segment_16 tss_seg;
2939 int ret;
2940 u32 new_tss_base = get_desc_base(new_desc);
2941
2942 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2943 &ctxt->exception);
2944 if (ret != X86EMUL_CONTINUE)
2945 return ret;
2946
2947 save_state_to_tss16(ctxt, &tss_seg);
2948
2949 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2950 &ctxt->exception);
2951 if (ret != X86EMUL_CONTINUE)
2952 return ret;
2953
2954 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2955 &ctxt->exception);
2956 if (ret != X86EMUL_CONTINUE)
2957 return ret;
2958
2959 if (old_tss_sel != 0xffff) {
2960 tss_seg.prev_task_link = old_tss_sel;
2961
2962 ret = ops->write_std(ctxt, new_tss_base,
2963 &tss_seg.prev_task_link,
2964 sizeof tss_seg.prev_task_link,
2965 &ctxt->exception);
2966 if (ret != X86EMUL_CONTINUE)
2967 return ret;
2968 }
2969
2970 return load_state_from_tss16(ctxt, &tss_seg);
2971 }
2972
2973 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
2974 struct tss_segment_32 *tss)
2975 {
2976 /* CR3 and ldt selector are not saved intentionally */
2977 tss->eip = ctxt->_eip;
2978 tss->eflags = ctxt->eflags;
2979 tss->eax = reg_read(ctxt, VCPU_REGS_RAX);
2980 tss->ecx = reg_read(ctxt, VCPU_REGS_RCX);
2981 tss->edx = reg_read(ctxt, VCPU_REGS_RDX);
2982 tss->ebx = reg_read(ctxt, VCPU_REGS_RBX);
2983 tss->esp = reg_read(ctxt, VCPU_REGS_RSP);
2984 tss->ebp = reg_read(ctxt, VCPU_REGS_RBP);
2985 tss->esi = reg_read(ctxt, VCPU_REGS_RSI);
2986 tss->edi = reg_read(ctxt, VCPU_REGS_RDI);
2987
2988 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2989 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2990 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2991 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2992 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS);
2993 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS);
2994 }
2995
2996 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
2997 struct tss_segment_32 *tss)
2998 {
2999 int ret;
3000 u8 cpl;
3001
3002 if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
3003 return emulate_gp(ctxt, 0);
3004 ctxt->_eip = tss->eip;
3005 ctxt->eflags = tss->eflags | 2;
3006
3007 /* General purpose registers */
3008 *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax;
3009 *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx;
3010 *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx;
3011 *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx;
3012 *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp;
3013 *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp;
3014 *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi;
3015 *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi;
3016
3017 /*
3018 * SDM says that segment selectors are loaded before segment
3019 * descriptors. This is important because CPL checks will
3020 * use CS.RPL.
3021 */
3022 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
3023 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
3024 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
3025 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
3026 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
3027 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS);
3028 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
3029
3030 /*
3031 * If we're switching between Protected Mode and VM86, we need to make
3032 * sure to update the mode before loading the segment descriptors so
3033 * that the selectors are interpreted correctly.
3034 */
3035 if (ctxt->eflags & X86_EFLAGS_VM) {
3036 ctxt->mode = X86EMUL_MODE_VM86;
3037 cpl = 3;
3038 } else {
3039 ctxt->mode = X86EMUL_MODE_PROT32;
3040 cpl = tss->cs & 3;
3041 }
3042
3043 /*
3044 * Now load segment descriptors. If fault happenes at this stage
3045 * it is handled in a context of new task
3046 */
3047 ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR,
3048 cpl, X86_TRANSFER_TASK_SWITCH, NULL);
3049 if (ret != X86EMUL_CONTINUE)
3050 return ret;
3051 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl,
3052 X86_TRANSFER_TASK_SWITCH, NULL);
3053 if (ret != X86EMUL_CONTINUE)
3054 return ret;
3055 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl,
3056 X86_TRANSFER_TASK_SWITCH, NULL);
3057 if (ret != X86EMUL_CONTINUE)
3058 return ret;
3059 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl,
3060 X86_TRANSFER_TASK_SWITCH, NULL);
3061 if (ret != X86EMUL_CONTINUE)
3062 return ret;
3063 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl,
3064 X86_TRANSFER_TASK_SWITCH, NULL);
3065 if (ret != X86EMUL_CONTINUE)
3066 return ret;
3067 ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl,
3068 X86_TRANSFER_TASK_SWITCH, NULL);
3069 if (ret != X86EMUL_CONTINUE)
3070 return ret;
3071 ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl,
3072 X86_TRANSFER_TASK_SWITCH, NULL);
3073
3074 return ret;
3075 }
3076
3077 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
3078 u16 tss_selector, u16 old_tss_sel,
3079 ulong old_tss_base, struct desc_struct *new_desc)
3080 {
3081 const struct x86_emulate_ops *ops = ctxt->ops;
3082 struct tss_segment_32 tss_seg;
3083 int ret;
3084 u32 new_tss_base = get_desc_base(new_desc);
3085 u32 eip_offset = offsetof(struct tss_segment_32, eip);
3086 u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector);
3087
3088 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
3089 &ctxt->exception);
3090 if (ret != X86EMUL_CONTINUE)
3091 return ret;
3092
3093 save_state_to_tss32(ctxt, &tss_seg);
3094
3095 /* Only GP registers and segment selectors are saved */
3096 ret = ops->write_std(ctxt, old_tss_base + eip_offset, &tss_seg.eip,
3097 ldt_sel_offset - eip_offset, &ctxt->exception);
3098 if (ret != X86EMUL_CONTINUE)
3099 return ret;
3100
3101 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
3102 &ctxt->exception);
3103 if (ret != X86EMUL_CONTINUE)
3104 return ret;
3105
3106 if (old_tss_sel != 0xffff) {
3107 tss_seg.prev_task_link = old_tss_sel;
3108
3109 ret = ops->write_std(ctxt, new_tss_base,
3110 &tss_seg.prev_task_link,
3111 sizeof tss_seg.prev_task_link,
3112 &ctxt->exception);
3113 if (ret != X86EMUL_CONTINUE)
3114 return ret;
3115 }
3116
3117 return load_state_from_tss32(ctxt, &tss_seg);
3118 }
3119
3120 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
3121 u16 tss_selector, int idt_index, int reason,
3122 bool has_error_code, u32 error_code)
3123 {
3124 const struct x86_emulate_ops *ops = ctxt->ops;
3125 struct desc_struct curr_tss_desc, next_tss_desc;
3126 int ret;
3127 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR);
3128 ulong old_tss_base =
3129 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR);
3130 u32 desc_limit;
3131 ulong desc_addr, dr7;
3132
3133 /* FIXME: old_tss_base == ~0 ? */
3134
3135 ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr);
3136 if (ret != X86EMUL_CONTINUE)
3137 return ret;
3138 ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr);
3139 if (ret != X86EMUL_CONTINUE)
3140 return ret;
3141
3142 /* FIXME: check that next_tss_desc is tss */
3143
3144 /*
3145 * Check privileges. The three cases are task switch caused by...
3146 *
3147 * 1. jmp/call/int to task gate: Check against DPL of the task gate
3148 * 2. Exception/IRQ/iret: No check is performed
3149 * 3. jmp/call to TSS/task-gate: No check is performed since the
3150 * hardware checks it before exiting.
3151 */
3152 if (reason == TASK_SWITCH_GATE) {
3153 if (idt_index != -1) {
3154 /* Software interrupts */
3155 struct desc_struct task_gate_desc;
3156 int dpl;
3157
3158 ret = read_interrupt_descriptor(ctxt, idt_index,
3159 &task_gate_desc);
3160 if (ret != X86EMUL_CONTINUE)
3161 return ret;
3162
3163 dpl = task_gate_desc.dpl;
3164 if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
3165 return emulate_gp(ctxt, (idt_index << 3) | 0x2);
3166 }
3167 }
3168
3169 desc_limit = desc_limit_scaled(&next_tss_desc);
3170 if (!next_tss_desc.p ||
3171 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
3172 desc_limit < 0x2b)) {
3173 return emulate_ts(ctxt, tss_selector & 0xfffc);
3174 }
3175
3176 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
3177 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
3178 write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
3179 }
3180
3181 if (reason == TASK_SWITCH_IRET)
3182 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
3183
3184 /* set back link to prev task only if NT bit is set in eflags
3185 note that old_tss_sel is not used after this point */
3186 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
3187 old_tss_sel = 0xffff;
3188
3189 if (next_tss_desc.type & 8)
3190 ret = task_switch_32(ctxt, tss_selector, old_tss_sel,
3191 old_tss_base, &next_tss_desc);
3192 else
3193 ret = task_switch_16(ctxt, tss_selector, old_tss_sel,
3194 old_tss_base, &next_tss_desc);
3195 if (ret != X86EMUL_CONTINUE)
3196 return ret;
3197
3198 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
3199 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
3200
3201 if (reason != TASK_SWITCH_IRET) {
3202 next_tss_desc.type |= (1 << 1); /* set busy flag */
3203 write_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
3204 }
3205
3206 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS);
3207 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR);
3208
3209 if (has_error_code) {
3210 ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
3211 ctxt->lock_prefix = 0;
3212 ctxt->src.val = (unsigned long) error_code;
3213 ret = em_push(ctxt);
3214 }
3215
3216 ops->get_dr(ctxt, 7, &dr7);
3217 ops->set_dr(ctxt, 7, dr7 & ~(DR_LOCAL_ENABLE_MASK | DR_LOCAL_SLOWDOWN));
3218
3219 return ret;
3220 }
3221
3222 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
3223 u16 tss_selector, int idt_index, int reason,
3224 bool has_error_code, u32 error_code)
3225 {
3226 int rc;
3227
3228 invalidate_registers(ctxt);
3229 ctxt->_eip = ctxt->eip;
3230 ctxt->dst.type = OP_NONE;
3231
3232 rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason,
3233 has_error_code, error_code);
3234
3235 if (rc == X86EMUL_CONTINUE) {
3236 ctxt->eip = ctxt->_eip;
3237 writeback_registers(ctxt);
3238 }
3239
3240 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
3241 }
3242
3243 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg,
3244 struct operand *op)
3245 {
3246 int df = (ctxt->eflags & X86_EFLAGS_DF) ? -op->count : op->count;
3247
3248 register_address_increment(ctxt, reg, df * op->bytes);
3249 op->addr.mem.ea = register_address(ctxt, reg);
3250 }
3251
3252 static int em_das(struct x86_emulate_ctxt *ctxt)
3253 {
3254 u8 al, old_al;
3255 bool af, cf, old_cf;
3256
3257 cf = ctxt->eflags & X86_EFLAGS_CF;
3258 al = ctxt->dst.val;
3259
3260 old_al = al;
3261 old_cf = cf;
3262 cf = false;
3263 af = ctxt->eflags & X86_EFLAGS_AF;
3264 if ((al & 0x0f) > 9 || af) {
3265 al -= 6;
3266 cf = old_cf | (al >= 250);
3267 af = true;
3268 } else {
3269 af = false;
3270 }
3271 if (old_al > 0x99 || old_cf) {
3272 al -= 0x60;
3273 cf = true;
3274 }
3275
3276 ctxt->dst.val = al;
3277 /* Set PF, ZF, SF */
3278 ctxt->src.type = OP_IMM;
3279 ctxt->src.val = 0;
3280 ctxt->src.bytes = 1;
3281 fastop(ctxt, em_or);
3282 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);
3283 if (cf)
3284 ctxt->eflags |= X86_EFLAGS_CF;
3285 if (af)
3286 ctxt->eflags |= X86_EFLAGS_AF;
3287 return X86EMUL_CONTINUE;
3288 }
3289
3290 static int em_aam(struct x86_emulate_ctxt *ctxt)
3291 {
3292 u8 al, ah;
3293
3294 if (ctxt->src.val == 0)
3295 return emulate_de(ctxt);
3296
3297 al = ctxt->dst.val & 0xff;
3298 ah = al / ctxt->src.val;
3299 al %= ctxt->src.val;
3300
3301 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8);
3302
3303 /* Set PF, ZF, SF */
3304 ctxt->src.type = OP_IMM;
3305 ctxt->src.val = 0;
3306 ctxt->src.bytes = 1;
3307 fastop(ctxt, em_or);
3308
3309 return X86EMUL_CONTINUE;
3310 }
3311
3312 static int em_aad(struct x86_emulate_ctxt *ctxt)
3313 {
3314 u8 al = ctxt->dst.val & 0xff;
3315 u8 ah = (ctxt->dst.val >> 8) & 0xff;
3316
3317 al = (al + (ah * ctxt->src.val)) & 0xff;
3318
3319 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al;
3320
3321 /* Set PF, ZF, SF */
3322 ctxt->src.type = OP_IMM;
3323 ctxt->src.val = 0;
3324 ctxt->src.bytes = 1;
3325 fastop(ctxt, em_or);
3326
3327 return X86EMUL_CONTINUE;
3328 }
3329
3330 static int em_call(struct x86_emulate_ctxt *ctxt)
3331 {
3332 int rc;
3333 long rel = ctxt->src.val;
3334
3335 ctxt->src.val = (unsigned long)ctxt->_eip;
3336 rc = jmp_rel(ctxt, rel);
3337 if (rc != X86EMUL_CONTINUE)
3338 return rc;
3339 return em_push(ctxt);
3340 }
3341
3342 static int em_call_far(struct x86_emulate_ctxt *ctxt)
3343 {
3344 u16 sel, old_cs;
3345 ulong old_eip;
3346 int rc;
3347 struct desc_struct old_desc, new_desc;
3348 const struct x86_emulate_ops *ops = ctxt->ops;
3349 int cpl = ctxt->ops->cpl(ctxt);
3350 enum x86emul_mode prev_mode = ctxt->mode;
3351
3352 old_eip = ctxt->_eip;
3353 ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS);
3354
3355 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
3356 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl,
3357 X86_TRANSFER_CALL_JMP, &new_desc);
3358 if (rc != X86EMUL_CONTINUE)
3359 return rc;
3360
3361 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc);
3362 if (rc != X86EMUL_CONTINUE)
3363 goto fail;
3364
3365 ctxt->src.val = old_cs;
3366 rc = em_push(ctxt);
3367 if (rc != X86EMUL_CONTINUE)
3368 goto fail;
3369
3370 ctxt->src.val = old_eip;
3371 rc = em_push(ctxt);
3372 /* If we failed, we tainted the memory, but the very least we should
3373 restore cs */
3374 if (rc != X86EMUL_CONTINUE) {
3375 pr_warn_once("faulting far call emulation tainted memory\n");
3376 goto fail;
3377 }
3378 return rc;
3379 fail:
3380 ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
3381 ctxt->mode = prev_mode;
3382 return rc;
3383
3384 }
3385
3386 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
3387 {
3388 int rc;
3389 unsigned long eip;
3390
3391 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
3392 if (rc != X86EMUL_CONTINUE)
3393 return rc;
3394 rc = assign_eip_near(ctxt, eip);
3395 if (rc != X86EMUL_CONTINUE)
3396 return rc;
3397 rsp_increment(ctxt, ctxt->src.val);
3398 return X86EMUL_CONTINUE;
3399 }
3400
3401 static int em_xchg(struct x86_emulate_ctxt *ctxt)
3402 {
3403 /* Write back the register source. */
3404 ctxt->src.val = ctxt->dst.val;
3405 write_register_operand(&ctxt->src);
3406
3407 /* Write back the memory destination with implicit LOCK prefix. */
3408 ctxt->dst.val = ctxt->src.orig_val;
3409 ctxt->lock_prefix = 1;
3410 return X86EMUL_CONTINUE;
3411 }
3412
3413 static int em_imul_3op(struct x86_emulate_ctxt *ctxt)
3414 {
3415 ctxt->dst.val = ctxt->src2.val;
3416 return fastop(ctxt, em_imul);
3417 }
3418
3419 static int em_cwd(struct x86_emulate_ctxt *ctxt)
3420 {
3421 ctxt->dst.type = OP_REG;
3422 ctxt->dst.bytes = ctxt->src.bytes;
3423 ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
3424 ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1);
3425
3426 return X86EMUL_CONTINUE;
3427 }
3428
3429 static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
3430 {
3431 u64 tsc = 0;
3432
3433 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc);
3434 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc;
3435 *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32;
3436 return X86EMUL_CONTINUE;
3437 }
3438
3439 static int em_rdpmc(struct x86_emulate_ctxt *ctxt)
3440 {
3441 u64 pmc;
3442
3443 if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc))
3444 return emulate_gp(ctxt, 0);
3445 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc;
3446 *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32;
3447 return X86EMUL_CONTINUE;
3448 }
3449
3450 static int em_mov(struct x86_emulate_ctxt *ctxt)
3451 {
3452 memcpy(ctxt->dst.valptr, ctxt->src.valptr, sizeof(ctxt->src.valptr));
3453 return X86EMUL_CONTINUE;
3454 }
3455
3456 #define FFL(x) bit(X86_FEATURE_##x)
3457
3458 static int em_movbe(struct x86_emulate_ctxt *ctxt)
3459 {
3460 u32 ebx, ecx, edx, eax = 1;
3461 u16 tmp;
3462
3463 /*
3464 * Check MOVBE is set in the guest-visible CPUID leaf.
3465 */
3466 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
3467 if (!(ecx & FFL(MOVBE)))
3468 return emulate_ud(ctxt);
3469
3470 switch (ctxt->op_bytes) {
3471 case 2:
3472 /*
3473 * From MOVBE definition: "...When the operand size is 16 bits,
3474 * the upper word of the destination register remains unchanged
3475 * ..."
3476 *
3477 * Both casting ->valptr and ->val to u16 breaks strict aliasing
3478 * rules so we have to do the operation almost per hand.
3479 */
3480 tmp = (u16)ctxt->src.val;
3481 ctxt->dst.val &= ~0xffffUL;
3482 ctxt->dst.val |= (unsigned long)swab16(tmp);
3483 break;
3484 case 4:
3485 ctxt->dst.val = swab32((u32)ctxt->src.val);
3486 break;
3487 case 8:
3488 ctxt->dst.val = swab64(ctxt->src.val);
3489 break;
3490 default:
3491 BUG();
3492 }
3493 return X86EMUL_CONTINUE;
3494 }
3495
3496 static int em_cr_write(struct x86_emulate_ctxt *ctxt)
3497 {
3498 if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val))
3499 return emulate_gp(ctxt, 0);
3500
3501 /* Disable writeback. */
3502 ctxt->dst.type = OP_NONE;
3503 return X86EMUL_CONTINUE;
3504 }
3505
3506 static int em_dr_write(struct x86_emulate_ctxt *ctxt)
3507 {
3508 unsigned long val;
3509
3510 if (ctxt->mode == X86EMUL_MODE_PROT64)
3511 val = ctxt->src.val & ~0ULL;
3512 else
3513 val = ctxt->src.val & ~0U;
3514
3515 /* #UD condition is already handled. */
3516 if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0)
3517 return emulate_gp(ctxt, 0);
3518
3519 /* Disable writeback. */
3520 ctxt->dst.type = OP_NONE;
3521 return X86EMUL_CONTINUE;
3522 }
3523
3524 static int em_wrmsr(struct x86_emulate_ctxt *ctxt)
3525 {
3526 u64 msr_data;
3527
3528 msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX)
3529 | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32);
3530 if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data))
3531 return emulate_gp(ctxt, 0);
3532
3533 return X86EMUL_CONTINUE;
3534 }
3535
3536 static int em_rdmsr(struct x86_emulate_ctxt *ctxt)
3537 {
3538 u64 msr_data;
3539
3540 if (ctxt->ops->get_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &msr_data))
3541 return emulate_gp(ctxt, 0);
3542
3543 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data;
3544 *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32;
3545 return X86EMUL_CONTINUE;
3546 }
3547
3548 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
3549 {
3550 if (ctxt->modrm_reg > VCPU_SREG_GS)
3551 return emulate_ud(ctxt);
3552
3553 ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);
3554 if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM)
3555 ctxt->dst.bytes = 2;
3556 return X86EMUL_CONTINUE;
3557 }
3558
3559 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
3560 {
3561 u16 sel = ctxt->src.val;
3562
3563 if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS)
3564 return emulate_ud(ctxt);
3565
3566 if (ctxt->modrm_reg == VCPU_SREG_SS)
3567 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
3568
3569 /* Disable writeback. */
3570 ctxt->dst.type = OP_NONE;
3571 return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);
3572 }
3573
3574 static int em_lldt(struct x86_emulate_ctxt *ctxt)
3575 {
3576 u16 sel = ctxt->src.val;
3577
3578 /* Disable writeback. */
3579 ctxt->dst.type = OP_NONE;
3580 return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR);
3581 }
3582
3583 static int em_ltr(struct x86_emulate_ctxt *ctxt)
3584 {
3585 u16 sel = ctxt->src.val;
3586
3587 /* Disable writeback. */
3588 ctxt->dst.type = OP_NONE;
3589 return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR);
3590 }
3591
3592 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
3593 {
3594 int rc;
3595 ulong linear;
3596
3597 rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear);
3598 if (rc == X86EMUL_CONTINUE)
3599 ctxt->ops->invlpg(ctxt, linear);
3600 /* Disable writeback. */
3601 ctxt->dst.type = OP_NONE;
3602 return X86EMUL_CONTINUE;
3603 }
3604
3605 static int em_clts(struct x86_emulate_ctxt *ctxt)
3606 {
3607 ulong cr0;
3608
3609 cr0 = ctxt->ops->get_cr(ctxt, 0);
3610 cr0 &= ~X86_CR0_TS;
3611 ctxt->ops->set_cr(ctxt, 0, cr0);
3612 return X86EMUL_CONTINUE;
3613 }
3614
3615 static int em_hypercall(struct x86_emulate_ctxt *ctxt)
3616 {
3617 int rc = ctxt->ops->fix_hypercall(ctxt);
3618
3619 if (rc != X86EMUL_CONTINUE)
3620 return rc;
3621
3622 /* Let the processor re-execute the fixed hypercall */
3623 ctxt->_eip = ctxt->eip;
3624 /* Disable writeback. */
3625 ctxt->dst.type = OP_NONE;
3626 return X86EMUL_CONTINUE;
3627 }
3628
3629 static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt,
3630 void (*get)(struct x86_emulate_ctxt *ctxt,
3631 struct desc_ptr *ptr))
3632 {
3633 struct desc_ptr desc_ptr;
3634
3635 if (ctxt->mode == X86EMUL_MODE_PROT64)
3636 ctxt->op_bytes = 8;
3637 get(ctxt, &desc_ptr);
3638 if (ctxt->op_bytes == 2) {
3639 ctxt->op_bytes = 4;
3640 desc_ptr.address &= 0x00ffffff;
3641 }
3642 /* Disable writeback. */
3643 ctxt->dst.type = OP_NONE;
3644 return segmented_write(ctxt, ctxt->dst.addr.mem,
3645 &desc_ptr, 2 + ctxt->op_bytes);
3646 }
3647
3648 static int em_sgdt(struct x86_emulate_ctxt *ctxt)
3649 {
3650 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt);
3651 }
3652
3653 static int em_sidt(struct x86_emulate_ctxt *ctxt)
3654 {
3655 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt);
3656 }
3657
3658 static int em_lgdt_lidt(struct x86_emulate_ctxt *ctxt, bool lgdt)
3659 {
3660 struct desc_ptr desc_ptr;
3661 int rc;
3662
3663 if (ctxt->mode == X86EMUL_MODE_PROT64)
3664 ctxt->op_bytes = 8;
3665 rc = read_descriptor(ctxt, ctxt->src.addr.mem,
3666 &desc_ptr.size, &desc_ptr.address,
3667 ctxt->op_bytes);
3668 if (rc != X86EMUL_CONTINUE)
3669 return rc;
3670 if (ctxt->mode == X86EMUL_MODE_PROT64 &&
3671 is_noncanonical_address(desc_ptr.address))
3672 return emulate_gp(ctxt, 0);
3673 if (lgdt)
3674 ctxt->ops->set_gdt(ctxt, &desc_ptr);
3675 else
3676 ctxt->ops->set_idt(ctxt, &desc_ptr);
3677 /* Disable writeback. */
3678 ctxt->dst.type = OP_NONE;
3679 return X86EMUL_CONTINUE;
3680 }
3681
3682 static int em_lgdt(struct x86_emulate_ctxt *ctxt)
3683 {
3684 return em_lgdt_lidt(ctxt, true);
3685 }
3686
3687 static int em_lidt(struct x86_emulate_ctxt *ctxt)
3688 {
3689 return em_lgdt_lidt(ctxt, false);
3690 }
3691
3692 static int em_smsw(struct x86_emulate_ctxt *ctxt)
3693 {
3694 if (ctxt->dst.type == OP_MEM)
3695 ctxt->dst.bytes = 2;
3696 ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0);
3697 return X86EMUL_CONTINUE;
3698 }
3699
3700 static int em_lmsw(struct x86_emulate_ctxt *ctxt)
3701 {
3702 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul)
3703 | (ctxt->src.val & 0x0f));
3704 ctxt->dst.type = OP_NONE;
3705 return X86EMUL_CONTINUE;
3706 }
3707
3708 static int em_loop(struct x86_emulate_ctxt *ctxt)
3709 {
3710 int rc = X86EMUL_CONTINUE;
3711
3712 register_address_increment(ctxt, VCPU_REGS_RCX, -1);
3713 if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) &&
3714 (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags)))
3715 rc = jmp_rel(ctxt, ctxt->src.val);
3716
3717 return rc;
3718 }
3719
3720 static int em_jcxz(struct x86_emulate_ctxt *ctxt)
3721 {
3722 int rc = X86EMUL_CONTINUE;
3723
3724 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0)
3725 rc = jmp_rel(ctxt, ctxt->src.val);
3726
3727 return rc;
3728 }
3729
3730 static int em_in(struct x86_emulate_ctxt *ctxt)
3731 {
3732 if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val,
3733 &ctxt->dst.val))
3734 return X86EMUL_IO_NEEDED;
3735
3736 return X86EMUL_CONTINUE;
3737 }
3738
3739 static int em_out(struct x86_emulate_ctxt *ctxt)
3740 {
3741 ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val,
3742 &ctxt->src.val, 1);
3743 /* Disable writeback. */
3744 ctxt->dst.type = OP_NONE;
3745 return X86EMUL_CONTINUE;
3746 }
3747
3748 static int em_cli(struct x86_emulate_ctxt *ctxt)
3749 {
3750 if (emulator_bad_iopl(ctxt))
3751 return emulate_gp(ctxt, 0);
3752
3753 ctxt->eflags &= ~X86_EFLAGS_IF;
3754 return X86EMUL_CONTINUE;
3755 }
3756
3757 static int em_sti(struct x86_emulate_ctxt *ctxt)
3758 {
3759 if (emulator_bad_iopl(ctxt))
3760 return emulate_gp(ctxt, 0);
3761
3762 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
3763 ctxt->eflags |= X86_EFLAGS_IF;
3764 return X86EMUL_CONTINUE;
3765 }
3766
3767 static int em_cpuid(struct x86_emulate_ctxt *ctxt)
3768 {
3769 u32 eax, ebx, ecx, edx;
3770
3771 eax = reg_read(ctxt, VCPU_REGS_RAX);
3772 ecx = reg_read(ctxt, VCPU_REGS_RCX);
3773 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
3774 *reg_write(ctxt, VCPU_REGS_RAX) = eax;
3775 *reg_write(ctxt, VCPU_REGS_RBX) = ebx;
3776 *reg_write(ctxt, VCPU_REGS_RCX) = ecx;
3777 *reg_write(ctxt, VCPU_REGS_RDX) = edx;
3778 return X86EMUL_CONTINUE;
3779 }
3780
3781 static int em_sahf(struct x86_emulate_ctxt *ctxt)
3782 {
3783 u32 flags;
3784
3785 flags = X86_EFLAGS_CF | X86_EFLAGS_PF | X86_EFLAGS_AF | X86_EFLAGS_ZF |
3786 X86_EFLAGS_SF;
3787 flags &= *reg_rmw(ctxt, VCPU_REGS_RAX) >> 8;
3788
3789 ctxt->eflags &= ~0xffUL;
3790 ctxt->eflags |= flags | X86_EFLAGS_FIXED;
3791 return X86EMUL_CONTINUE;
3792 }
3793
3794 static int em_lahf(struct x86_emulate_ctxt *ctxt)
3795 {
3796 *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL;
3797 *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8;
3798 return X86EMUL_CONTINUE;
3799 }
3800
3801 static int em_bswap(struct x86_emulate_ctxt *ctxt)
3802 {
3803 switch (ctxt->op_bytes) {
3804 #ifdef CONFIG_X86_64
3805 case 8:
3806 asm("bswap %0" : "+r"(ctxt->dst.val));
3807 break;
3808 #endif
3809 default:
3810 asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val));
3811 break;
3812 }
3813 return X86EMUL_CONTINUE;
3814 }
3815
3816 static int em_clflush(struct x86_emulate_ctxt *ctxt)
3817 {
3818 /* emulating clflush regardless of cpuid */
3819 return X86EMUL_CONTINUE;
3820 }
3821
3822 static int em_movsxd(struct x86_emulate_ctxt *ctxt)
3823 {
3824 ctxt->dst.val = (s32) ctxt->src.val;
3825 return X86EMUL_CONTINUE;
3826 }
3827
3828 static bool valid_cr(int nr)
3829 {
3830 switch (nr) {
3831 case 0:
3832 case 2 ... 4:
3833 case 8:
3834 return true;
3835 default:
3836 return false;
3837 }
3838 }
3839
3840 static int check_cr_read(struct x86_emulate_ctxt *ctxt)
3841 {
3842 if (!valid_cr(ctxt->modrm_reg))
3843 return emulate_ud(ctxt);
3844
3845 return X86EMUL_CONTINUE;
3846 }
3847
3848 static int check_cr_write(struct x86_emulate_ctxt *ctxt)
3849 {
3850 u64 new_val = ctxt->src.val64;
3851 int cr = ctxt->modrm_reg;
3852 u64 efer = 0;
3853
3854 static u64 cr_reserved_bits[] = {
3855 0xffffffff00000000ULL,
3856 0, 0, 0, /* CR3 checked later */
3857 CR4_RESERVED_BITS,
3858 0, 0, 0,
3859 CR8_RESERVED_BITS,
3860 };
3861
3862 if (!valid_cr(cr))
3863 return emulate_ud(ctxt);
3864
3865 if (new_val & cr_reserved_bits[cr])
3866 return emulate_gp(ctxt, 0);
3867
3868 switch (cr) {
3869 case 0: {
3870 u64 cr4;
3871 if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) ||
3872 ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD)))
3873 return emulate_gp(ctxt, 0);
3874
3875 cr4 = ctxt->ops->get_cr(ctxt, 4);
3876 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3877
3878 if ((new_val & X86_CR0_PG) && (efer & EFER_LME) &&
3879 !(cr4 & X86_CR4_PAE))
3880 return emulate_gp(ctxt, 0);
3881
3882 break;
3883 }
3884 case 3: {
3885 u64 rsvd = 0;
3886
3887 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3888 if (efer & EFER_LMA)
3889 rsvd = CR3_L_MODE_RESERVED_BITS & ~CR3_PCID_INVD;
3890
3891 if (new_val & rsvd)
3892 return emulate_gp(ctxt, 0);
3893
3894 break;
3895 }
3896 case 4: {
3897 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3898
3899 if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE))
3900 return emulate_gp(ctxt, 0);
3901
3902 break;
3903 }
3904 }
3905
3906 return X86EMUL_CONTINUE;
3907 }
3908
3909 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt)
3910 {
3911 unsigned long dr7;
3912
3913 ctxt->ops->get_dr(ctxt, 7, &dr7);
3914
3915 /* Check if DR7.Global_Enable is set */
3916 return dr7 & (1 << 13);
3917 }
3918
3919 static int check_dr_read(struct x86_emulate_ctxt *ctxt)
3920 {
3921 int dr = ctxt->modrm_reg;
3922 u64 cr4;
3923
3924 if (dr > 7)
3925 return emulate_ud(ctxt);
3926
3927 cr4 = ctxt->ops->get_cr(ctxt, 4);
3928 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
3929 return emulate_ud(ctxt);
3930
3931 if (check_dr7_gd(ctxt)) {
3932 ulong dr6;
3933
3934 ctxt->ops->get_dr(ctxt, 6, &dr6);
3935 dr6 &= ~15;
3936 dr6 |= DR6_BD | DR6_RTM;
3937 ctxt->ops->set_dr(ctxt, 6, dr6);
3938 return emulate_db(ctxt);
3939 }
3940
3941 return X86EMUL_CONTINUE;
3942 }
3943
3944 static int check_dr_write(struct x86_emulate_ctxt *ctxt)
3945 {
3946 u64 new_val = ctxt->src.val64;
3947 int dr = ctxt->modrm_reg;
3948
3949 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL))
3950 return emulate_gp(ctxt, 0);
3951
3952 return check_dr_read(ctxt);
3953 }
3954
3955 static int check_svme(struct x86_emulate_ctxt *ctxt)
3956 {
3957 u64 efer;
3958
3959 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3960
3961 if (!(efer & EFER_SVME))
3962 return emulate_ud(ctxt);
3963
3964 return X86EMUL_CONTINUE;
3965 }
3966
3967 static int check_svme_pa(struct x86_emulate_ctxt *ctxt)
3968 {
3969 u64 rax = reg_read(ctxt, VCPU_REGS_RAX);
3970
3971 /* Valid physical address? */
3972 if (rax & 0xffff000000000000ULL)
3973 return emulate_gp(ctxt, 0);
3974
3975 return check_svme(ctxt);
3976 }
3977
3978 static int check_rdtsc(struct x86_emulate_ctxt *ctxt)
3979 {
3980 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3981
3982 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt))
3983 return emulate_ud(ctxt);
3984
3985 return X86EMUL_CONTINUE;
3986 }
3987
3988 static int check_rdpmc(struct x86_emulate_ctxt *ctxt)
3989 {
3990 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3991 u64 rcx = reg_read(ctxt, VCPU_REGS_RCX);
3992
3993 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) ||
3994 ctxt->ops->check_pmc(ctxt, rcx))
3995 return emulate_gp(ctxt, 0);
3996
3997 return X86EMUL_CONTINUE;
3998 }
3999
4000 static int check_perm_in(struct x86_emulate_ctxt *ctxt)
4001 {
4002 ctxt->dst.bytes = min(ctxt->dst.bytes, 4u);
4003 if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes))
4004 return emulate_gp(ctxt, 0);
4005
4006 return X86EMUL_CONTINUE;
4007 }
4008
4009 static int check_perm_out(struct x86_emulate_ctxt *ctxt)
4010 {
4011 ctxt->src.bytes = min(ctxt->src.bytes, 4u);
4012 if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes))
4013 return emulate_gp(ctxt, 0);
4014
4015 return X86EMUL_CONTINUE;
4016 }
4017
4018 #define D(_y) { .flags = (_y) }
4019 #define DI(_y, _i) { .flags = (_y)|Intercept, .intercept = x86_intercept_##_i }
4020 #define DIP(_y, _i, _p) { .flags = (_y)|Intercept|CheckPerm, \
4021 .intercept = x86_intercept_##_i, .check_perm = (_p) }
4022 #define N D(NotImpl)
4023 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) }
4024 #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) }
4025 #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) }
4026 #define ID(_f, _i) { .flags = ((_f) | InstrDual | ModRM), .u.idual = (_i) }
4027 #define MD(_f, _m) { .flags = ((_f) | ModeDual), .u.mdual = (_m) }
4028 #define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) }
4029 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
4030 #define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) }
4031 #define II(_f, _e, _i) \
4032 { .flags = (_f)|Intercept, .u.execute = (_e), .intercept = x86_intercept_##_i }
4033 #define IIP(_f, _e, _i, _p) \
4034 { .flags = (_f)|Intercept|CheckPerm, .u.execute = (_e), \
4035 .intercept = x86_intercept_##_i, .check_perm = (_p) }
4036 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }
4037
4038 #define D2bv(_f) D((_f) | ByteOp), D(_f)
4039 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p)
4040 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e)
4041 #define F2bv(_f, _e) F((_f) | ByteOp, _e), F(_f, _e)
4042 #define I2bvIP(_f, _e, _i, _p) \
4043 IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p)
4044
4045 #define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e), \
4046 F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \
4047 F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)
4048
4049 static const struct opcode group7_rm0[] = {
4050 N,
4051 I(SrcNone | Priv | EmulateOnUD, em_hypercall),
4052 N, N, N, N, N, N,
4053 };
4054
4055 static const struct opcode group7_rm1[] = {
4056 DI(SrcNone | Priv, monitor),
4057 DI(SrcNone | Priv, mwait),
4058 N, N, N, N, N, N,
4059 };
4060
4061 static const struct opcode group7_rm3[] = {
4062 DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa),
4063 II(SrcNone | Prot | EmulateOnUD, em_hypercall, vmmcall),
4064 DIP(SrcNone | Prot | Priv, vmload, check_svme_pa),
4065 DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa),
4066 DIP(SrcNone | Prot | Priv, stgi, check_svme),
4067 DIP(SrcNone | Prot | Priv, clgi, check_svme),
4068 DIP(SrcNone | Prot | Priv, skinit, check_svme),
4069 DIP(SrcNone | Prot | Priv, invlpga, check_svme),
4070 };
4071
4072 static const struct opcode group7_rm7[] = {
4073 N,
4074 DIP(SrcNone, rdtscp, check_rdtsc),
4075 N, N, N, N, N, N,
4076 };
4077
4078 static const struct opcode group1[] = {
4079 F(Lock, em_add),
4080 F(Lock | PageTable, em_or),
4081 F(Lock, em_adc),
4082 F(Lock, em_sbb),
4083 F(Lock | PageTable, em_and),
4084 F(Lock, em_sub),
4085 F(Lock, em_xor),
4086 F(NoWrite, em_cmp),
4087 };
4088
4089 static const struct opcode group1A[] = {
4090 I(DstMem | SrcNone | Mov | Stack | IncSP, em_pop), N, N, N, N, N, N, N,
4091 };
4092
4093 static const struct opcode group2[] = {
4094 F(DstMem | ModRM, em_rol),
4095 F(DstMem | ModRM, em_ror),
4096 F(DstMem | ModRM, em_rcl),
4097 F(DstMem | ModRM, em_rcr),
4098 F(DstMem | ModRM, em_shl),
4099 F(DstMem | ModRM, em_shr),
4100 F(DstMem | ModRM, em_shl),
4101 F(DstMem | ModRM, em_sar),
4102 };
4103
4104 static const struct opcode group3[] = {
4105 F(DstMem | SrcImm | NoWrite, em_test),
4106 F(DstMem | SrcImm | NoWrite, em_test),
4107 F(DstMem | SrcNone | Lock, em_not),
4108 F(DstMem | SrcNone | Lock, em_neg),
4109 F(DstXacc | Src2Mem, em_mul_ex),
4110 F(DstXacc | Src2Mem, em_imul_ex),
4111 F(DstXacc | Src2Mem, em_div_ex),
4112 F(DstXacc | Src2Mem, em_idiv_ex),
4113 };
4114
4115 static const struct opcode group4[] = {
4116 F(ByteOp | DstMem | SrcNone | Lock, em_inc),
4117 F(ByteOp | DstMem | SrcNone | Lock, em_dec),
4118 N, N, N, N, N, N,
4119 };
4120
4121 static const struct opcode group5[] = {
4122 F(DstMem | SrcNone | Lock, em_inc),
4123 F(DstMem | SrcNone | Lock, em_dec),
4124 I(SrcMem | NearBranch, em_call_near_abs),
4125 I(SrcMemFAddr | ImplicitOps, em_call_far),
4126 I(SrcMem | NearBranch, em_jmp_abs),
4127 I(SrcMemFAddr | ImplicitOps, em_jmp_far),
4128 I(SrcMem | Stack, em_push), D(Undefined),
4129 };
4130
4131 static const struct opcode group6[] = {
4132 DI(Prot | DstMem, sldt),
4133 DI(Prot | DstMem, str),
4134 II(Prot | Priv | SrcMem16, em_lldt, lldt),
4135 II(Prot | Priv | SrcMem16, em_ltr, ltr),
4136 N, N, N, N,
4137 };
4138
4139 static const struct group_dual group7 = { {
4140 II(Mov | DstMem, em_sgdt, sgdt),
4141 II(Mov | DstMem, em_sidt, sidt),
4142 II(SrcMem | Priv, em_lgdt, lgdt),
4143 II(SrcMem | Priv, em_lidt, lidt),
4144 II(SrcNone | DstMem | Mov, em_smsw, smsw), N,
4145 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw),
4146 II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg),
4147 }, {
4148 EXT(0, group7_rm0),
4149 EXT(0, group7_rm1),
4150 N, EXT(0, group7_rm3),
4151 II(SrcNone | DstMem | Mov, em_smsw, smsw), N,
4152 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw),
4153 EXT(0, group7_rm7),
4154 } };
4155
4156 static const struct opcode group8[] = {
4157 N, N, N, N,
4158 F(DstMem | SrcImmByte | NoWrite, em_bt),
4159 F(DstMem | SrcImmByte | Lock | PageTable, em_bts),
4160 F(DstMem | SrcImmByte | Lock, em_btr),
4161 F(DstMem | SrcImmByte | Lock | PageTable, em_btc),
4162 };
4163
4164 static const struct group_dual group9 = { {
4165 N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N,
4166 }, {
4167 N, N, N, N, N, N, N, N,
4168 } };
4169
4170 static const struct opcode group11[] = {
4171 I(DstMem | SrcImm | Mov | PageTable, em_mov),
4172 X7(D(Undefined)),
4173 };
4174
4175 static const struct gprefix pfx_0f_ae_7 = {
4176 I(SrcMem | ByteOp, em_clflush), N, N, N,
4177 };
4178
4179 static const struct group_dual group15 = { {
4180 N, N, N, N, N, N, N, GP(0, &pfx_0f_ae_7),
4181 }, {
4182 N, N, N, N, N, N, N, N,
4183 } };
4184
4185 static const struct gprefix pfx_0f_6f_0f_7f = {
4186 I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov),
4187 };
4188
4189 static const struct instr_dual instr_dual_0f_2b = {
4190 I(0, em_mov), N
4191 };
4192
4193 static const struct gprefix pfx_0f_2b = {
4194 ID(0, &instr_dual_0f_2b), ID(0, &instr_dual_0f_2b), N, N,
4195 };
4196
4197 static const struct gprefix pfx_0f_28_0f_29 = {
4198 I(Aligned, em_mov), I(Aligned, em_mov), N, N,
4199 };
4200
4201 static const struct gprefix pfx_0f_e7 = {
4202 N, I(Sse, em_mov), N, N,
4203 };
4204
4205 static const struct escape escape_d9 = { {
4206 N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstcw),
4207 }, {
4208 /* 0xC0 - 0xC7 */
4209 N, N, N, N, N, N, N, N,
4210 /* 0xC8 - 0xCF */
4211 N, N, N, N, N, N, N, N,
4212 /* 0xD0 - 0xC7 */
4213 N, N, N, N, N, N, N, N,
4214 /* 0xD8 - 0xDF */
4215 N, N, N, N, N, N, N, N,
4216 /* 0xE0 - 0xE7 */
4217 N, N, N, N, N, N, N, N,
4218 /* 0xE8 - 0xEF */
4219 N, N, N, N, N, N, N, N,
4220 /* 0xF0 - 0xF7 */
4221 N, N, N, N, N, N, N, N,
4222 /* 0xF8 - 0xFF */
4223 N, N, N, N, N, N, N, N,
4224 } };
4225
4226 static const struct escape escape_db = { {
4227 N, N, N, N, N, N, N, N,
4228 }, {
4229 /* 0xC0 - 0xC7 */
4230 N, N, N, N, N, N, N, N,
4231 /* 0xC8 - 0xCF */
4232 N, N, N, N, N, N, N, N,
4233 /* 0xD0 - 0xC7 */
4234 N, N, N, N, N, N, N, N,
4235 /* 0xD8 - 0xDF */
4236 N, N, N, N, N, N, N, N,
4237 /* 0xE0 - 0xE7 */
4238 N, N, N, I(ImplicitOps, em_fninit), N, N, N, N,
4239 /* 0xE8 - 0xEF */
4240 N, N, N, N, N, N, N, N,
4241 /* 0xF0 - 0xF7 */
4242 N, N, N, N, N, N, N, N,
4243 /* 0xF8 - 0xFF */
4244 N, N, N, N, N, N, N, N,
4245 } };
4246
4247 static const struct escape escape_dd = { {
4248 N, N, N, N, N, N, N, I(DstMem16 | Mov, em_fnstsw),
4249 }, {
4250 /* 0xC0 - 0xC7 */
4251 N, N, N, N, N, N, N, N,
4252 /* 0xC8 - 0xCF */
4253 N, N, N, N, N, N, N, N,
4254 /* 0xD0 - 0xC7 */
4255 N, N, N, N, N, N, N, N,
4256 /* 0xD8 - 0xDF */
4257 N, N, N, N, N, N, N, N,
4258 /* 0xE0 - 0xE7 */
4259 N, N, N, N, N, N, N, N,
4260 /* 0xE8 - 0xEF */
4261 N, N, N, N, N, N, N, N,
4262 /* 0xF0 - 0xF7 */
4263 N, N, N, N, N, N, N, N,
4264 /* 0xF8 - 0xFF */
4265 N, N, N, N, N, N, N, N,
4266 } };
4267
4268 static const struct instr_dual instr_dual_0f_c3 = {
4269 I(DstMem | SrcReg | ModRM | No16 | Mov, em_mov), N
4270 };
4271
4272 static const struct mode_dual mode_dual_63 = {
4273 N, I(DstReg | SrcMem32 | ModRM | Mov, em_movsxd)
4274 };
4275
4276 static const struct opcode opcode_table[256] = {
4277 /* 0x00 - 0x07 */
4278 F6ALU(Lock, em_add),
4279 I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg),
4280 I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg),
4281 /* 0x08 - 0x0F */
4282 F6ALU(Lock | PageTable, em_or),
4283 I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg),
4284 N,
4285 /* 0x10 - 0x17 */
4286 F6ALU(Lock, em_adc),
4287 I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg),
4288 I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg),
4289 /* 0x18 - 0x1F */
4290 F6ALU(Lock, em_sbb),
4291 I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg),
4292 I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg),
4293 /* 0x20 - 0x27 */
4294 F6ALU(Lock | PageTable, em_and), N, N,
4295 /* 0x28 - 0x2F */
4296 F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),
4297 /* 0x30 - 0x37 */
4298 F6ALU(Lock, em_xor), N, N,
4299 /* 0x38 - 0x3F */
4300 F6ALU(NoWrite, em_cmp), N, N,
4301 /* 0x40 - 0x4F */
4302 X8(F(DstReg, em_inc)), X8(F(DstReg, em_dec)),
4303 /* 0x50 - 0x57 */
4304 X8(I(SrcReg | Stack, em_push)),
4305 /* 0x58 - 0x5F */
4306 X8(I(DstReg | Stack, em_pop)),
4307 /* 0x60 - 0x67 */
4308 I(ImplicitOps | Stack | No64, em_pusha),
4309 I(ImplicitOps | Stack | No64, em_popa),
4310 N, MD(ModRM, &mode_dual_63),
4311 N, N, N, N,
4312 /* 0x68 - 0x6F */
4313 I(SrcImm | Mov | Stack, em_push),
4314 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
4315 I(SrcImmByte | Mov | Stack, em_push),
4316 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
4317 I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */
4318 I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */
4319 /* 0x70 - 0x7F */
4320 X16(D(SrcImmByte | NearBranch)),
4321 /* 0x80 - 0x87 */
4322 G(ByteOp | DstMem | SrcImm, group1),
4323 G(DstMem | SrcImm, group1),
4324 G(ByteOp | DstMem | SrcImm | No64, group1),
4325 G(DstMem | SrcImmByte, group1),
4326 F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test),
4327 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg),
4328 /* 0x88 - 0x8F */
4329 I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov),
4330 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
4331 I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg),
4332 D(ModRM | SrcMem | NoAccess | DstReg),
4333 I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm),
4334 G(0, group1A),
4335 /* 0x90 - 0x97 */
4336 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)),
4337 /* 0x98 - 0x9F */
4338 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
4339 I(SrcImmFAddr | No64, em_call_far), N,
4340 II(ImplicitOps | Stack, em_pushf, pushf),
4341 II(ImplicitOps | Stack, em_popf, popf),
4342 I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf),
4343 /* 0xA0 - 0xA7 */
4344 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
4345 I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov),
4346 I2bv(SrcSI | DstDI | Mov | String, em_mov),
4347 F2bv(SrcSI | DstDI | String | NoWrite, em_cmp_r),
4348 /* 0xA8 - 0xAF */
4349 F2bv(DstAcc | SrcImm | NoWrite, em_test),
4350 I2bv(SrcAcc | DstDI | Mov | String, em_mov),
4351 I2bv(SrcSI | DstAcc | Mov | String, em_mov),
4352 F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r),
4353 /* 0xB0 - 0xB7 */
4354 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
4355 /* 0xB8 - 0xBF */
4356 X8(I(DstReg | SrcImm64 | Mov, em_mov)),
4357 /* 0xC0 - 0xC7 */
4358 G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2),
4359 I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm),
4360 I(ImplicitOps | NearBranch, em_ret),
4361 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),
4362 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
4363 G(ByteOp, group11), G(0, group11),
4364 /* 0xC8 - 0xCF */
4365 I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave),
4366 I(ImplicitOps | SrcImmU16, em_ret_far_imm),
4367 I(ImplicitOps, em_ret_far),
4368 D(ImplicitOps), DI(SrcImmByte, intn),
4369 D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
4370 /* 0xD0 - 0xD7 */
4371 G(Src2One | ByteOp, group2), G(Src2One, group2),
4372 G(Src2CL | ByteOp, group2), G(Src2CL, group2),
4373 I(DstAcc | SrcImmUByte | No64, em_aam),
4374 I(DstAcc | SrcImmUByte | No64, em_aad),
4375 F(DstAcc | ByteOp | No64, em_salc),
4376 I(DstAcc | SrcXLat | ByteOp, em_mov),
4377 /* 0xD8 - 0xDF */
4378 N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,
4379 /* 0xE0 - 0xE7 */
4380 X3(I(SrcImmByte | NearBranch, em_loop)),
4381 I(SrcImmByte | NearBranch, em_jcxz),
4382 I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in),
4383 I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out),
4384 /* 0xE8 - 0xEF */
4385 I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps | NearBranch),
4386 I(SrcImmFAddr | No64, em_jmp_far),
4387 D(SrcImmByte | ImplicitOps | NearBranch),
4388 I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in),
4389 I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out),
4390 /* 0xF0 - 0xF7 */
4391 N, DI(ImplicitOps, icebp), N, N,
4392 DI(ImplicitOps | Priv, hlt), D(ImplicitOps),
4393 G(ByteOp, group3), G(0, group3),
4394 /* 0xF8 - 0xFF */
4395 D(ImplicitOps), D(ImplicitOps),
4396 I(ImplicitOps, em_cli), I(ImplicitOps, em_sti),
4397 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5),
4398 };
4399
4400 static const struct opcode twobyte_table[256] = {
4401 /* 0x00 - 0x0F */
4402 G(0, group6), GD(0, &group7), N, N,
4403 N, I(ImplicitOps | EmulateOnUD, em_syscall),
4404 II(ImplicitOps | Priv, em_clts, clts), N,
4405 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N,
4406 N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N,
4407 /* 0x10 - 0x1F */
4408 N, N, N, N, N, N, N, N,
4409 D(ImplicitOps | ModRM | SrcMem | NoAccess),
4410 N, N, N, N, N, N, D(ImplicitOps | ModRM | SrcMem | NoAccess),
4411 /* 0x20 - 0x2F */
4412 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_read),
4413 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read),
4414 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_cr_write, cr_write,
4415 check_cr_write),
4416 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_dr_write, dr_write,
4417 check_dr_write),
4418 N, N, N, N,
4419 GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_28_0f_29),
4420 GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_28_0f_29),
4421 N, GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_2b),
4422 N, N, N, N,
4423 /* 0x30 - 0x3F */
4424 II(ImplicitOps | Priv, em_wrmsr, wrmsr),
4425 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
4426 II(ImplicitOps | Priv, em_rdmsr, rdmsr),
4427 IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc),
4428 I(ImplicitOps | EmulateOnUD, em_sysenter),
4429 I(ImplicitOps | Priv | EmulateOnUD, em_sysexit),
4430 N, N,
4431 N, N, N, N, N, N, N, N,
4432 /* 0x40 - 0x4F */
4433 X16(D(DstReg | SrcMem | ModRM)),
4434 /* 0x50 - 0x5F */
4435 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
4436 /* 0x60 - 0x6F */
4437 N, N, N, N,
4438 N, N, N, N,
4439 N, N, N, N,
4440 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f),
4441 /* 0x70 - 0x7F */
4442 N, N, N, N,
4443 N, N, N, N,
4444 N, N, N, N,
4445 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),
4446 /* 0x80 - 0x8F */
4447 X16(D(SrcImm | NearBranch)),
4448 /* 0x90 - 0x9F */
4449 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
4450 /* 0xA0 - 0xA7 */
4451 I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
4452 II(ImplicitOps, em_cpuid, cpuid),
4453 F(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt),
4454 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld),
4455 F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N,
4456 /* 0xA8 - 0xAF */
4457 I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
4458 II(No64 | EmulateOnUD | ImplicitOps, em_rsm, rsm),
4459 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
4460 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
4461 F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
4462 GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul),
4463 /* 0xB0 - 0xB7 */
4464 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable | SrcWrite, em_cmpxchg),
4465 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
4466 F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
4467 I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
4468 I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
4469 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
4470 /* 0xB8 - 0xBF */
4471 N, N,
4472 G(BitOp, group8),
4473 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
4474 I(DstReg | SrcMem | ModRM, em_bsf_c),
4475 I(DstReg | SrcMem | ModRM, em_bsr_c),
4476 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
4477 /* 0xC0 - 0xC7 */
4478 F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),
4479 N, ID(0, &instr_dual_0f_c3),
4480 N, N, N, GD(0, &group9),
4481 /* 0xC8 - 0xCF */
4482 X8(I(DstReg, em_bswap)),
4483 /* 0xD0 - 0xDF */
4484 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
4485 /* 0xE0 - 0xEF */
4486 N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_e7),
4487 N, N, N, N, N, N, N, N,
4488 /* 0xF0 - 0xFF */
4489 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N
4490 };
4491
4492 static const struct instr_dual instr_dual_0f_38_f0 = {
4493 I(DstReg | SrcMem | Mov, em_movbe), N
4494 };
4495
4496 static const struct instr_dual instr_dual_0f_38_f1 = {
4497 I(DstMem | SrcReg | Mov, em_movbe), N
4498 };
4499
4500 static const struct gprefix three_byte_0f_38_f0 = {
4501 ID(0, &instr_dual_0f_38_f0), N, N, N
4502 };
4503
4504 static const struct gprefix three_byte_0f_38_f1 = {
4505 ID(0, &instr_dual_0f_38_f1), N, N, N
4506 };
4507
4508 /*
4509 * Insns below are selected by the prefix which indexed by the third opcode
4510 * byte.
4511 */
4512 static const struct opcode opcode_map_0f_38[256] = {
4513 /* 0x00 - 0x7f */
4514 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N),
4515 /* 0x80 - 0xef */
4516 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N),
4517 /* 0xf0 - 0xf1 */
4518 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f0),
4519 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f1),
4520 /* 0xf2 - 0xff */
4521 N, N, X4(N), X8(N)
4522 };
4523
4524 #undef D
4525 #undef N
4526 #undef G
4527 #undef GD
4528 #undef I
4529 #undef GP
4530 #undef EXT
4531 #undef MD
4532 #undef ID
4533
4534 #undef D2bv
4535 #undef D2bvIP
4536 #undef I2bv
4537 #undef I2bvIP
4538 #undef I6ALU
4539
4540 static unsigned imm_size(struct x86_emulate_ctxt *ctxt)
4541 {
4542 unsigned size;
4543
4544 size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4545 if (size == 8)
4546 size = 4;
4547 return size;
4548 }
4549
4550 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op,
4551 unsigned size, bool sign_extension)
4552 {
4553 int rc = X86EMUL_CONTINUE;
4554
4555 op->type = OP_IMM;
4556 op->bytes = size;
4557 op->addr.mem.ea = ctxt->_eip;
4558 /* NB. Immediates are sign-extended as necessary. */
4559 switch (op->bytes) {
4560 case 1:
4561 op->val = insn_fetch(s8, ctxt);
4562 break;
4563 case 2:
4564 op->val = insn_fetch(s16, ctxt);
4565 break;
4566 case 4:
4567 op->val = insn_fetch(s32, ctxt);
4568 break;
4569 case 8:
4570 op->val = insn_fetch(s64, ctxt);
4571 break;
4572 }
4573 if (!sign_extension) {
4574 switch (op->bytes) {
4575 case 1:
4576 op->val &= 0xff;
4577 break;
4578 case 2:
4579 op->val &= 0xffff;
4580 break;
4581 case 4:
4582 op->val &= 0xffffffff;
4583 break;
4584 }
4585 }
4586 done:
4587 return rc;
4588 }
4589
4590 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
4591 unsigned d)
4592 {
4593 int rc = X86EMUL_CONTINUE;
4594
4595 switch (d) {
4596 case OpReg:
4597 decode_register_operand(ctxt, op);
4598 break;
4599 case OpImmUByte:
4600 rc = decode_imm(ctxt, op, 1, false);
4601 break;
4602 case OpMem:
4603 ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4604 mem_common:
4605 *op = ctxt->memop;
4606 ctxt->memopp = op;
4607 if (ctxt->d & BitOp)
4608 fetch_bit_operand(ctxt);
4609 op->orig_val = op->val;
4610 break;
4611 case OpMem64:
4612 ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8;
4613 goto mem_common;
4614 case OpAcc:
4615 op->type = OP_REG;
4616 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4617 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
4618 fetch_register_operand(op);
4619 op->orig_val = op->val;
4620 break;
4621 case OpAccLo:
4622 op->type = OP_REG;
4623 op->bytes = (ctxt->d & ByteOp) ? 2 : ctxt->op_bytes;
4624 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
4625 fetch_register_operand(op);
4626 op->orig_val = op->val;
4627 break;
4628 case OpAccHi:
4629 if (ctxt->d & ByteOp) {
4630 op->type = OP_NONE;
4631 break;
4632 }
4633 op->type = OP_REG;
4634 op->bytes = ctxt->op_bytes;
4635 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
4636 fetch_register_operand(op);
4637 op->orig_val = op->val;
4638 break;
4639 case OpDI:
4640 op->type = OP_MEM;
4641 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4642 op->addr.mem.ea =
4643 register_address(ctxt, VCPU_REGS_RDI);
4644 op->addr.mem.seg = VCPU_SREG_ES;
4645 op->val = 0;
4646 op->count = 1;
4647 break;
4648 case OpDX:
4649 op->type = OP_REG;
4650 op->bytes = 2;
4651 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
4652 fetch_register_operand(op);
4653 break;
4654 case OpCL:
4655 op->type = OP_IMM;
4656 op->bytes = 1;
4657 op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff;
4658 break;
4659 case OpImmByte:
4660 rc = decode_imm(ctxt, op, 1, true);
4661 break;
4662 case OpOne:
4663 op->type = OP_IMM;
4664 op->bytes = 1;
4665 op->val = 1;
4666 break;
4667 case OpImm:
4668 rc = decode_imm(ctxt, op, imm_size(ctxt), true);
4669 break;
4670 case OpImm64:
4671 rc = decode_imm(ctxt, op, ctxt->op_bytes, true);
4672 break;
4673 case OpMem8:
4674 ctxt->memop.bytes = 1;
4675 if (ctxt->memop.type == OP_REG) {
4676 ctxt->memop.addr.reg = decode_register(ctxt,
4677 ctxt->modrm_rm, true);
4678 fetch_register_operand(&ctxt->memop);
4679 }
4680 goto mem_common;
4681 case OpMem16:
4682 ctxt->memop.bytes = 2;
4683 goto mem_common;
4684 case OpMem32:
4685 ctxt->memop.bytes = 4;
4686 goto mem_common;
4687 case OpImmU16:
4688 rc = decode_imm(ctxt, op, 2, false);
4689 break;
4690 case OpImmU:
4691 rc = decode_imm(ctxt, op, imm_size(ctxt), false);
4692 break;
4693 case OpSI:
4694 op->type = OP_MEM;
4695 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4696 op->addr.mem.ea =
4697 register_address(ctxt, VCPU_REGS_RSI);
4698 op->addr.mem.seg = ctxt->seg_override;
4699 op->val = 0;
4700 op->count = 1;
4701 break;
4702 case OpXLat:
4703 op->type = OP_MEM;
4704 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4705 op->addr.mem.ea =
4706 address_mask(ctxt,
4707 reg_read(ctxt, VCPU_REGS_RBX) +
4708 (reg_read(ctxt, VCPU_REGS_RAX) & 0xff));
4709 op->addr.mem.seg = ctxt->seg_override;
4710 op->val = 0;
4711 break;
4712 case OpImmFAddr:
4713 op->type = OP_IMM;
4714 op->addr.mem.ea = ctxt->_eip;
4715 op->bytes = ctxt->op_bytes + 2;
4716 insn_fetch_arr(op->valptr, op->bytes, ctxt);
4717 break;
4718 case OpMemFAddr:
4719 ctxt->memop.bytes = ctxt->op_bytes + 2;
4720 goto mem_common;
4721 case OpES:
4722 op->type = OP_IMM;
4723 op->val = VCPU_SREG_ES;
4724 break;
4725 case OpCS:
4726 op->type = OP_IMM;
4727 op->val = VCPU_SREG_CS;
4728 break;
4729 case OpSS:
4730 op->type = OP_IMM;
4731 op->val = VCPU_SREG_SS;
4732 break;
4733 case OpDS:
4734 op->type = OP_IMM;
4735 op->val = VCPU_SREG_DS;
4736 break;
4737 case OpFS:
4738 op->type = OP_IMM;
4739 op->val = VCPU_SREG_FS;
4740 break;
4741 case OpGS:
4742 op->type = OP_IMM;
4743 op->val = VCPU_SREG_GS;
4744 break;
4745 case OpImplicit:
4746 /* Special instructions do their own operand decoding. */
4747 default:
4748 op->type = OP_NONE; /* Disable writeback. */
4749 break;
4750 }
4751
4752 done:
4753 return rc;
4754 }
4755
4756 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
4757 {
4758 int rc = X86EMUL_CONTINUE;
4759 int mode = ctxt->mode;
4760 int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
4761 bool op_prefix = false;
4762 bool has_seg_override = false;
4763 struct opcode opcode;
4764
4765 ctxt->memop.type = OP_NONE;
4766 ctxt->memopp = NULL;
4767 ctxt->_eip = ctxt->eip;
4768 ctxt->fetch.ptr = ctxt->fetch.data;
4769 ctxt->fetch.end = ctxt->fetch.data + insn_len;
4770 ctxt->opcode_len = 1;
4771 if (insn_len > 0)
4772 memcpy(ctxt->fetch.data, insn, insn_len);
4773 else {
4774 rc = __do_insn_fetch_bytes(ctxt, 1);
4775 if (rc != X86EMUL_CONTINUE)
4776 return rc;
4777 }
4778
4779 switch (mode) {
4780 case X86EMUL_MODE_REAL:
4781 case X86EMUL_MODE_VM86:
4782 case X86EMUL_MODE_PROT16:
4783 def_op_bytes = def_ad_bytes = 2;
4784 break;
4785 case X86EMUL_MODE_PROT32:
4786 def_op_bytes = def_ad_bytes = 4;
4787 break;
4788 #ifdef CONFIG_X86_64
4789 case X86EMUL_MODE_PROT64:
4790 def_op_bytes = 4;
4791 def_ad_bytes = 8;
4792 break;
4793 #endif
4794 default:
4795 return EMULATION_FAILED;
4796 }
4797
4798 ctxt->op_bytes = def_op_bytes;
4799 ctxt->ad_bytes = def_ad_bytes;
4800
4801 /* Legacy prefixes. */
4802 for (;;) {
4803 switch (ctxt->b = insn_fetch(u8, ctxt)) {
4804 case 0x66: /* operand-size override */
4805 op_prefix = true;
4806 /* switch between 2/4 bytes */
4807 ctxt->op_bytes = def_op_bytes ^ 6;
4808 break;
4809 case 0x67: /* address-size override */
4810 if (mode == X86EMUL_MODE_PROT64)
4811 /* switch between 4/8 bytes */
4812 ctxt->ad_bytes = def_ad_bytes ^ 12;
4813 else
4814 /* switch between 2/4 bytes */
4815 ctxt->ad_bytes = def_ad_bytes ^ 6;
4816 break;
4817 case 0x26: /* ES override */
4818 case 0x2e: /* CS override */
4819 case 0x36: /* SS override */
4820 case 0x3e: /* DS override */
4821 has_seg_override = true;
4822 ctxt->seg_override = (ctxt->b >> 3) & 3;
4823 break;
4824 case 0x64: /* FS override */
4825 case 0x65: /* GS override */
4826 has_seg_override = true;
4827 ctxt->seg_override = ctxt->b & 7;
4828 break;
4829 case 0x40 ... 0x4f: /* REX */
4830 if (mode != X86EMUL_MODE_PROT64)
4831 goto done_prefixes;
4832 ctxt->rex_prefix = ctxt->b;
4833 continue;
4834 case 0xf0: /* LOCK */
4835 ctxt->lock_prefix = 1;
4836 break;
4837 case 0xf2: /* REPNE/REPNZ */
4838 case 0xf3: /* REP/REPE/REPZ */
4839 ctxt->rep_prefix = ctxt->b;
4840 break;
4841 default:
4842 goto done_prefixes;
4843 }
4844
4845 /* Any legacy prefix after a REX prefix nullifies its effect. */
4846
4847 ctxt->rex_prefix = 0;
4848 }
4849
4850 done_prefixes:
4851
4852 /* REX prefix. */
4853 if (ctxt->rex_prefix & 8)
4854 ctxt->op_bytes = 8; /* REX.W */
4855
4856 /* Opcode byte(s). */
4857 opcode = opcode_table[ctxt->b];
4858 /* Two-byte opcode? */
4859 if (ctxt->b == 0x0f) {
4860 ctxt->opcode_len = 2;
4861 ctxt->b = insn_fetch(u8, ctxt);
4862 opcode = twobyte_table[ctxt->b];
4863
4864 /* 0F_38 opcode map */
4865 if (ctxt->b == 0x38) {
4866 ctxt->opcode_len = 3;
4867 ctxt->b = insn_fetch(u8, ctxt);
4868 opcode = opcode_map_0f_38[ctxt->b];
4869 }
4870 }
4871 ctxt->d = opcode.flags;
4872
4873 if (ctxt->d & ModRM)
4874 ctxt->modrm = insn_fetch(u8, ctxt);
4875
4876 /* vex-prefix instructions are not implemented */
4877 if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) &&
4878 (mode == X86EMUL_MODE_PROT64 || (ctxt->modrm & 0xc0) == 0xc0)) {
4879 ctxt->d = NotImpl;
4880 }
4881
4882 while (ctxt->d & GroupMask) {
4883 switch (ctxt->d & GroupMask) {
4884 case Group:
4885 goffset = (ctxt->modrm >> 3) & 7;
4886 opcode = opcode.u.group[goffset];
4887 break;
4888 case GroupDual:
4889 goffset = (ctxt->modrm >> 3) & 7;
4890 if ((ctxt->modrm >> 6) == 3)
4891 opcode = opcode.u.gdual->mod3[goffset];
4892 else
4893 opcode = opcode.u.gdual->mod012[goffset];
4894 break;
4895 case RMExt:
4896 goffset = ctxt->modrm & 7;
4897 opcode = opcode.u.group[goffset];
4898 break;
4899 case Prefix:
4900 if (ctxt->rep_prefix && op_prefix)
4901 return EMULATION_FAILED;
4902 simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
4903 switch (simd_prefix) {
4904 case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
4905 case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
4906 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
4907 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
4908 }
4909 break;
4910 case Escape:
4911 if (ctxt->modrm > 0xbf)
4912 opcode = opcode.u.esc->high[ctxt->modrm - 0xc0];
4913 else
4914 opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7];
4915 break;
4916 case InstrDual:
4917 if ((ctxt->modrm >> 6) == 3)
4918 opcode = opcode.u.idual->mod3;
4919 else
4920 opcode = opcode.u.idual->mod012;
4921 break;
4922 case ModeDual:
4923 if (ctxt->mode == X86EMUL_MODE_PROT64)
4924 opcode = opcode.u.mdual->mode64;
4925 else
4926 opcode = opcode.u.mdual->mode32;
4927 break;
4928 default:
4929 return EMULATION_FAILED;
4930 }
4931
4932 ctxt->d &= ~(u64)GroupMask;
4933 ctxt->d |= opcode.flags;
4934 }
4935
4936 /* Unrecognised? */
4937 if (ctxt->d == 0)
4938 return EMULATION_FAILED;
4939
4940 ctxt->execute = opcode.u.execute;
4941
4942 if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD)))
4943 return EMULATION_FAILED;
4944
4945 if (unlikely(ctxt->d &
4946 (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch|
4947 No16))) {
4948 /*
4949 * These are copied unconditionally here, and checked unconditionally
4950 * in x86_emulate_insn.
4951 */
4952 ctxt->check_perm = opcode.check_perm;
4953 ctxt->intercept = opcode.intercept;
4954
4955 if (ctxt->d & NotImpl)
4956 return EMULATION_FAILED;
4957
4958 if (mode == X86EMUL_MODE_PROT64) {
4959 if (ctxt->op_bytes == 4 && (ctxt->d & Stack))
4960 ctxt->op_bytes = 8;
4961 else if (ctxt->d & NearBranch)
4962 ctxt->op_bytes = 8;
4963 }
4964
4965 if (ctxt->d & Op3264) {
4966 if (mode == X86EMUL_MODE_PROT64)
4967 ctxt->op_bytes = 8;
4968 else
4969 ctxt->op_bytes = 4;
4970 }
4971
4972 if ((ctxt->d & No16) && ctxt->op_bytes == 2)
4973 ctxt->op_bytes = 4;
4974
4975 if (ctxt->d & Sse)
4976 ctxt->op_bytes = 16;
4977 else if (ctxt->d & Mmx)
4978 ctxt->op_bytes = 8;
4979 }
4980
4981 /* ModRM and SIB bytes. */
4982 if (ctxt->d & ModRM) {
4983 rc = decode_modrm(ctxt, &ctxt->memop);
4984 if (!has_seg_override) {
4985 has_seg_override = true;
4986 ctxt->seg_override = ctxt->modrm_seg;
4987 }
4988 } else if (ctxt->d & MemAbs)
4989 rc = decode_abs(ctxt, &ctxt->memop);
4990 if (rc != X86EMUL_CONTINUE)
4991 goto done;
4992
4993 if (!has_seg_override)
4994 ctxt->seg_override = VCPU_SREG_DS;
4995
4996 ctxt->memop.addr.mem.seg = ctxt->seg_override;
4997
4998 /*
4999 * Decode and fetch the source operand: register, memory
5000 * or immediate.
5001 */
5002 rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask);
5003 if (rc != X86EMUL_CONTINUE)
5004 goto done;
5005
5006 /*
5007 * Decode and fetch the second source operand: register, memory
5008 * or immediate.
5009 */
5010 rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask);
5011 if (rc != X86EMUL_CONTINUE)
5012 goto done;
5013
5014 /* Decode and fetch the destination operand: register or memory. */
5015 rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
5016
5017 if (ctxt->rip_relative)
5018 ctxt->memopp->addr.mem.ea = address_mask(ctxt,
5019 ctxt->memopp->addr.mem.ea + ctxt->_eip);
5020
5021 done:
5022 return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
5023 }
5024
5025 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt)
5026 {
5027 return ctxt->d & PageTable;
5028 }
5029
5030 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
5031 {
5032 /* The second termination condition only applies for REPE
5033 * and REPNE. Test if the repeat string operation prefix is
5034 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
5035 * corresponding termination condition according to:
5036 * - if REPE/REPZ and ZF = 0 then done
5037 * - if REPNE/REPNZ and ZF = 1 then done
5038 */
5039 if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) ||
5040 (ctxt->b == 0xae) || (ctxt->b == 0xaf))
5041 && (((ctxt->rep_prefix == REPE_PREFIX) &&
5042 ((ctxt->eflags & X86_EFLAGS_ZF) == 0))
5043 || ((ctxt->rep_prefix == REPNE_PREFIX) &&
5044 ((ctxt->eflags & X86_EFLAGS_ZF) == X86_EFLAGS_ZF))))
5045 return true;
5046
5047 return false;
5048 }
5049
5050 static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
5051 {
5052 bool fault = false;
5053
5054 ctxt->ops->get_fpu(ctxt);
5055 asm volatile("1: fwait \n\t"
5056 "2: \n\t"
5057 ".pushsection .fixup,\"ax\" \n\t"
5058 "3: \n\t"
5059 "movb $1, %[fault] \n\t"
5060 "jmp 2b \n\t"
5061 ".popsection \n\t"
5062 _ASM_EXTABLE(1b, 3b)
5063 : [fault]"+qm"(fault));
5064 ctxt->ops->put_fpu(ctxt);
5065
5066 if (unlikely(fault))
5067 return emulate_exception(ctxt, MF_VECTOR, 0, false);
5068
5069 return X86EMUL_CONTINUE;
5070 }
5071
5072 static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt,
5073 struct operand *op)
5074 {
5075 if (op->type == OP_MM)
5076 read_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
5077 }
5078
5079 static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))
5080 {
5081 ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF;
5082 if (!(ctxt->d & ByteOp))
5083 fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE;
5084 asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n"
5085 : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags),
5086 [fastop]"+S"(fop)
5087 : "c"(ctxt->src2.val));
5088 ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK);
5089 if (!fop) /* exception is returned in fop variable */
5090 return emulate_de(ctxt);
5091 return X86EMUL_CONTINUE;
5092 }
5093
5094 void init_decode_cache(struct x86_emulate_ctxt *ctxt)
5095 {
5096 memset(&ctxt->rip_relative, 0,
5097 (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
5098
5099 ctxt->io_read.pos = 0;
5100 ctxt->io_read.end = 0;
5101 ctxt->mem_read.end = 0;
5102 }
5103
5104 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
5105 {
5106 const struct x86_emulate_ops *ops = ctxt->ops;
5107 int rc = X86EMUL_CONTINUE;
5108 int saved_dst_type = ctxt->dst.type;
5109
5110 ctxt->mem_read.pos = 0;
5111
5112 /* LOCK prefix is allowed only with some instructions */
5113 if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) {
5114 rc = emulate_ud(ctxt);
5115 goto done;
5116 }
5117
5118 if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) {
5119 rc = emulate_ud(ctxt);
5120 goto done;
5121 }
5122
5123 if (unlikely(ctxt->d &
5124 (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) {
5125 if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) ||
5126 (ctxt->d & Undefined)) {
5127 rc = emulate_ud(ctxt);
5128 goto done;
5129 }
5130
5131 if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM)))
5132 || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) {
5133 rc = emulate_ud(ctxt);
5134 goto done;
5135 }
5136
5137 if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) {
5138 rc = emulate_nm(ctxt);
5139 goto done;
5140 }
5141
5142 if (ctxt->d & Mmx) {
5143 rc = flush_pending_x87_faults(ctxt);
5144 if (rc != X86EMUL_CONTINUE)
5145 goto done;
5146 /*
5147 * Now that we know the fpu is exception safe, we can fetch
5148 * operands from it.
5149 */
5150 fetch_possible_mmx_operand(ctxt, &ctxt->src);
5151 fetch_possible_mmx_operand(ctxt, &ctxt->src2);
5152 if (!(ctxt->d & Mov))
5153 fetch_possible_mmx_operand(ctxt, &ctxt->dst);
5154 }
5155
5156 if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && ctxt->intercept) {
5157 rc = emulator_check_intercept(ctxt, ctxt->intercept,
5158 X86_ICPT_PRE_EXCEPT);
5159 if (rc != X86EMUL_CONTINUE)
5160 goto done;
5161 }
5162
5163 /* Instruction can only be executed in protected mode */
5164 if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) {
5165 rc = emulate_ud(ctxt);
5166 goto done;
5167 }
5168
5169 /* Privileged instruction can be executed only in CPL=0 */
5170 if ((ctxt->d & Priv) && ops->cpl(ctxt)) {
5171 if (ctxt->d & PrivUD)
5172 rc = emulate_ud(ctxt);
5173 else
5174 rc = emulate_gp(ctxt, 0);
5175 goto done;
5176 }
5177
5178 /* Do instruction specific permission checks */
5179 if (ctxt->d & CheckPerm) {
5180 rc = ctxt->check_perm(ctxt);
5181 if (rc != X86EMUL_CONTINUE)
5182 goto done;
5183 }
5184
5185 if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) {
5186 rc = emulator_check_intercept(ctxt, ctxt->intercept,
5187 X86_ICPT_POST_EXCEPT);
5188 if (rc != X86EMUL_CONTINUE)
5189 goto done;
5190 }
5191
5192 if (ctxt->rep_prefix && (ctxt->d & String)) {
5193 /* All REP prefixes have the same first termination condition */
5194 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) {
5195 string_registers_quirk(ctxt);
5196 ctxt->eip = ctxt->_eip;
5197 ctxt->eflags &= ~X86_EFLAGS_RF;
5198 goto done;
5199 }
5200 }
5201 }
5202
5203 if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) {
5204 rc = segmented_read(ctxt, ctxt->src.addr.mem,
5205 ctxt->src.valptr, ctxt->src.bytes);
5206 if (rc != X86EMUL_CONTINUE)
5207 goto done;
5208 ctxt->src.orig_val64 = ctxt->src.val64;
5209 }
5210
5211 if (ctxt->src2.type == OP_MEM) {
5212 rc = segmented_read(ctxt, ctxt->src2.addr.mem,
5213 &ctxt->src2.val, ctxt->src2.bytes);
5214 if (rc != X86EMUL_CONTINUE)
5215 goto done;
5216 }
5217
5218 if ((ctxt->d & DstMask) == ImplicitOps)
5219 goto special_insn;
5220
5221
5222 if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) {
5223 /* optimisation - avoid slow emulated read if Mov */
5224 rc = segmented_read(ctxt, ctxt->dst.addr.mem,
5225 &ctxt->dst.val, ctxt->dst.bytes);
5226 if (rc != X86EMUL_CONTINUE) {
5227 if (!(ctxt->d & NoWrite) &&
5228 rc == X86EMUL_PROPAGATE_FAULT &&
5229 ctxt->exception.vector == PF_VECTOR)
5230 ctxt->exception.error_code |= PFERR_WRITE_MASK;
5231 goto done;
5232 }
5233 }
5234 /* Copy full 64-bit value for CMPXCHG8B. */
5235 ctxt->dst.orig_val64 = ctxt->dst.val64;
5236
5237 special_insn:
5238
5239 if (unlikely(ctxt->emul_flags & X86EMUL_GUEST_MASK) && (ctxt->d & Intercept)) {
5240 rc = emulator_check_intercept(ctxt, ctxt->intercept,
5241 X86_ICPT_POST_MEMACCESS);
5242 if (rc != X86EMUL_CONTINUE)
5243 goto done;
5244 }
5245
5246 if (ctxt->rep_prefix && (ctxt->d & String))
5247 ctxt->eflags |= X86_EFLAGS_RF;
5248 else
5249 ctxt->eflags &= ~X86_EFLAGS_RF;
5250
5251 if (ctxt->execute) {
5252 if (ctxt->d & Fastop) {
5253 void (*fop)(struct fastop *) = (void *)ctxt->execute;
5254 rc = fastop(ctxt, fop);
5255 if (rc != X86EMUL_CONTINUE)
5256 goto done;
5257 goto writeback;
5258 }
5259 rc = ctxt->execute(ctxt);
5260 if (rc != X86EMUL_CONTINUE)
5261 goto done;
5262 goto writeback;
5263 }
5264
5265 if (ctxt->opcode_len == 2)
5266 goto twobyte_insn;
5267 else if (ctxt->opcode_len == 3)
5268 goto threebyte_insn;
5269
5270 switch (ctxt->b) {
5271 case 0x70 ... 0x7f: /* jcc (short) */
5272 if (test_cc(ctxt->b, ctxt->eflags))
5273 rc = jmp_rel(ctxt, ctxt->src.val);
5274 break;
5275 case 0x8d: /* lea r16/r32, m */
5276 ctxt->dst.val = ctxt->src.addr.mem.ea;
5277 break;
5278 case 0x90 ... 0x97: /* nop / xchg reg, rax */
5279 if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX))
5280 ctxt->dst.type = OP_NONE;
5281 else
5282 rc = em_xchg(ctxt);
5283 break;
5284 case 0x98: /* cbw/cwde/cdqe */
5285 switch (ctxt->op_bytes) {
5286 case 2: ctxt->dst.val = (s8)ctxt->dst.val; break;
5287 case 4: ctxt->dst.val = (s16)ctxt->dst.val; break;
5288 case 8: ctxt->dst.val = (s32)ctxt->dst.val; break;
5289 }
5290 break;
5291 case 0xcc: /* int3 */
5292 rc = emulate_int(ctxt, 3);
5293 break;
5294 case 0xcd: /* int n */
5295 rc = emulate_int(ctxt, ctxt->src.val);
5296 break;
5297 case 0xce: /* into */
5298 if (ctxt->eflags & X86_EFLAGS_OF)
5299 rc = emulate_int(ctxt, 4);
5300 break;
5301 case 0xe9: /* jmp rel */
5302 case 0xeb: /* jmp rel short */
5303 rc = jmp_rel(ctxt, ctxt->src.val);
5304 ctxt->dst.type = OP_NONE; /* Disable writeback. */
5305 break;
5306 case 0xf4: /* hlt */
5307 ctxt->ops->halt(ctxt);
5308 break;
5309 case 0xf5: /* cmc */
5310 /* complement carry flag from eflags reg */
5311 ctxt->eflags ^= X86_EFLAGS_CF;
5312 break;
5313 case 0xf8: /* clc */
5314 ctxt->eflags &= ~X86_EFLAGS_CF;
5315 break;
5316 case 0xf9: /* stc */
5317 ctxt->eflags |= X86_EFLAGS_CF;
5318 break;
5319 case 0xfc: /* cld */
5320 ctxt->eflags &= ~X86_EFLAGS_DF;
5321 break;
5322 case 0xfd: /* std */
5323 ctxt->eflags |= X86_EFLAGS_DF;
5324 break;
5325 default:
5326 goto cannot_emulate;
5327 }
5328
5329 if (rc != X86EMUL_CONTINUE)
5330 goto done;
5331
5332 writeback:
5333 if (ctxt->d & SrcWrite) {
5334 BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR);
5335 rc = writeback(ctxt, &ctxt->src);
5336 if (rc != X86EMUL_CONTINUE)
5337 goto done;
5338 }
5339 if (!(ctxt->d & NoWrite)) {
5340 rc = writeback(ctxt, &ctxt->dst);
5341 if (rc != X86EMUL_CONTINUE)
5342 goto done;
5343 }
5344
5345 /*
5346 * restore dst type in case the decoding will be reused
5347 * (happens for string instruction )
5348 */
5349 ctxt->dst.type = saved_dst_type;
5350
5351 if ((ctxt->d & SrcMask) == SrcSI)
5352 string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src);
5353
5354 if ((ctxt->d & DstMask) == DstDI)
5355 string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst);
5356
5357 if (ctxt->rep_prefix && (ctxt->d & String)) {
5358 unsigned int count;
5359 struct read_cache *r = &ctxt->io_read;
5360 if ((ctxt->d & SrcMask) == SrcSI)
5361 count = ctxt->src.count;
5362 else
5363 count = ctxt->dst.count;
5364 register_address_increment(ctxt, VCPU_REGS_RCX, -count);
5365
5366 if (!string_insn_completed(ctxt)) {
5367 /*
5368 * Re-enter guest when pio read ahead buffer is empty
5369 * or, if it is not used, after each 1024 iteration.
5370 */
5371 if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) &&
5372 (r->end == 0 || r->end != r->pos)) {
5373 /*
5374 * Reset read cache. Usually happens before
5375 * decode, but since instruction is restarted
5376 * we have to do it here.
5377 */
5378 ctxt->mem_read.end = 0;
5379 writeback_registers(ctxt);
5380 return EMULATION_RESTART;
5381 }
5382 goto done; /* skip rip writeback */
5383 }
5384 ctxt->eflags &= ~X86_EFLAGS_RF;
5385 }
5386
5387 ctxt->eip = ctxt->_eip;
5388
5389 done:
5390 if (rc == X86EMUL_PROPAGATE_FAULT) {
5391 WARN_ON(ctxt->exception.vector > 0x1f);
5392 ctxt->have_exception = true;
5393 }
5394 if (rc == X86EMUL_INTERCEPTED)
5395 return EMULATION_INTERCEPTED;
5396
5397 if (rc == X86EMUL_CONTINUE)
5398 writeback_registers(ctxt);
5399
5400 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
5401
5402 twobyte_insn:
5403 switch (ctxt->b) {
5404 case 0x09: /* wbinvd */
5405 (ctxt->ops->wbinvd)(ctxt);
5406 break;
5407 case 0x08: /* invd */
5408 case 0x0d: /* GrpP (prefetch) */
5409 case 0x18: /* Grp16 (prefetch/nop) */
5410 case 0x1f: /* nop */
5411 break;
5412 case 0x20: /* mov cr, reg */
5413 ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg);
5414 break;
5415 case 0x21: /* mov from dr to reg */
5416 ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val);
5417 break;
5418 case 0x40 ... 0x4f: /* cmov */
5419 if (test_cc(ctxt->b, ctxt->eflags))
5420 ctxt->dst.val = ctxt->src.val;
5421 else if (ctxt->op_bytes != 4)
5422 ctxt->dst.type = OP_NONE; /* no writeback */
5423 break;
5424 case 0x80 ... 0x8f: /* jnz rel, etc*/
5425 if (test_cc(ctxt->b, ctxt->eflags))
5426 rc = jmp_rel(ctxt, ctxt->src.val);
5427 break;
5428 case 0x90 ... 0x9f: /* setcc r/m8 */
5429 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
5430 break;
5431 case 0xb6 ... 0xb7: /* movzx */
5432 ctxt->dst.bytes = ctxt->op_bytes;
5433 ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val
5434 : (u16) ctxt->src.val;
5435 break;
5436 case 0xbe ... 0xbf: /* movsx */
5437 ctxt->dst.bytes = ctxt->op_bytes;
5438 ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val :
5439 (s16) ctxt->src.val;
5440 break;
5441 default:
5442 goto cannot_emulate;
5443 }
5444
5445 threebyte_insn:
5446
5447 if (rc != X86EMUL_CONTINUE)
5448 goto done;
5449
5450 goto writeback;
5451
5452 cannot_emulate:
5453 return EMULATION_FAILED;
5454 }
5455
5456 void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt)
5457 {
5458 invalidate_registers(ctxt);
5459 }
5460
5461 void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt)
5462 {
5463 writeback_registers(ctxt);
5464 }
Linux kernel - Deliverables
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