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[mirror_ubuntu-bionic-kernel.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
29 #include "x86.h"
30 #include "tss.h"
31
32 /*
33 * Operand types
34 */
35 #define OpNone 0ull
36 #define OpImplicit 1ull /* No generic decode */
37 #define OpReg 2ull /* Register */
38 #define OpMem 3ull /* Memory */
39 #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */
40 #define OpDI 5ull /* ES:DI/EDI/RDI */
41 #define OpMem64 6ull /* Memory, 64-bit */
42 #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */
43 #define OpDX 8ull /* DX register */
44 #define OpCL 9ull /* CL register (for shifts) */
45 #define OpImmByte 10ull /* 8-bit sign extended immediate */
46 #define OpOne 11ull /* Implied 1 */
47 #define OpImm 12ull /* Sign extended up to 32-bit immediate */
48 #define OpMem16 13ull /* Memory operand (16-bit). */
49 #define OpMem32 14ull /* Memory operand (32-bit). */
50 #define OpImmU 15ull /* Immediate operand, zero extended */
51 #define OpSI 16ull /* SI/ESI/RSI */
52 #define OpImmFAddr 17ull /* Immediate far address */
53 #define OpMemFAddr 18ull /* Far address in memory */
54 #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */
55 #define OpES 20ull /* ES */
56 #define OpCS 21ull /* CS */
57 #define OpSS 22ull /* SS */
58 #define OpDS 23ull /* DS */
59 #define OpFS 24ull /* FS */
60 #define OpGS 25ull /* GS */
61 #define OpMem8 26ull /* 8-bit zero extended memory operand */
62 #define OpImm64 27ull /* Sign extended 16/32/64-bit immediate */
63 #define OpXLat 28ull /* memory at BX/EBX/RBX + zero-extended AL */
64 #define OpAccLo 29ull /* Low part of extended acc (AX/AX/EAX/RAX) */
65 #define OpAccHi 30ull /* High part of extended acc (-/DX/EDX/RDX) */
66
67 #define OpBits 5 /* Width of operand field */
68 #define OpMask ((1ull << OpBits) - 1)
69
70 /*
71 * Opcode effective-address decode tables.
72 * Note that we only emulate instructions that have at least one memory
73 * operand (excluding implicit stack references). We assume that stack
74 * references and instruction fetches will never occur in special memory
75 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
76 * not be handled.
77 */
78
79 /* Operand sizes: 8-bit operands or specified/overridden size. */
80 #define ByteOp (1<<0) /* 8-bit operands. */
81 /* Destination operand type. */
82 #define DstShift 1
83 #define ImplicitOps (OpImplicit << DstShift)
84 #define DstReg (OpReg << DstShift)
85 #define DstMem (OpMem << DstShift)
86 #define DstAcc (OpAcc << DstShift)
87 #define DstDI (OpDI << DstShift)
88 #define DstMem64 (OpMem64 << DstShift)
89 #define DstImmUByte (OpImmUByte << DstShift)
90 #define DstDX (OpDX << DstShift)
91 #define DstAccLo (OpAccLo << DstShift)
92 #define DstMask (OpMask << DstShift)
93 /* Source operand type. */
94 #define SrcShift 6
95 #define SrcNone (OpNone << SrcShift)
96 #define SrcReg (OpReg << SrcShift)
97 #define SrcMem (OpMem << SrcShift)
98 #define SrcMem16 (OpMem16 << SrcShift)
99 #define SrcMem32 (OpMem32 << SrcShift)
100 #define SrcImm (OpImm << SrcShift)
101 #define SrcImmByte (OpImmByte << SrcShift)
102 #define SrcOne (OpOne << SrcShift)
103 #define SrcImmUByte (OpImmUByte << SrcShift)
104 #define SrcImmU (OpImmU << SrcShift)
105 #define SrcSI (OpSI << SrcShift)
106 #define SrcXLat (OpXLat << SrcShift)
107 #define SrcImmFAddr (OpImmFAddr << SrcShift)
108 #define SrcMemFAddr (OpMemFAddr << SrcShift)
109 #define SrcAcc (OpAcc << SrcShift)
110 #define SrcImmU16 (OpImmU16 << SrcShift)
111 #define SrcImm64 (OpImm64 << SrcShift)
112 #define SrcDX (OpDX << SrcShift)
113 #define SrcMem8 (OpMem8 << SrcShift)
114 #define SrcAccHi (OpAccHi << SrcShift)
115 #define SrcMask (OpMask << SrcShift)
116 #define BitOp (1<<11)
117 #define MemAbs (1<<12) /* Memory operand is absolute displacement */
118 #define String (1<<13) /* String instruction (rep capable) */
119 #define Stack (1<<14) /* Stack instruction (push/pop) */
120 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */
121 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */
122 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */
123 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */
124 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */
125 #define Escape (5<<15) /* Escape to coprocessor instruction */
126 #define InstrDual (6<<15) /* Alternate instruction decoding of mod == 3 */
127 #define Sse (1<<18) /* SSE Vector instruction */
128 /* Generic ModRM decode. */
129 #define ModRM (1<<19)
130 /* Destination is only written; never read. */
131 #define Mov (1<<20)
132 /* Misc flags */
133 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */
134 #define EmulateOnUD (1<<22) /* Emulate if unsupported by the host */
135 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
136 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */
137 #define Undefined (1<<25) /* No Such Instruction */
138 #define Lock (1<<26) /* lock prefix is allowed for the instruction */
139 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
140 #define No64 (1<<28)
141 #define PageTable (1 << 29) /* instruction used to write page table */
142 #define NotImpl (1 << 30) /* instruction is not implemented */
143 /* Source 2 operand type */
144 #define Src2Shift (31)
145 #define Src2None (OpNone << Src2Shift)
146 #define Src2Mem (OpMem << Src2Shift)
147 #define Src2CL (OpCL << Src2Shift)
148 #define Src2ImmByte (OpImmByte << Src2Shift)
149 #define Src2One (OpOne << Src2Shift)
150 #define Src2Imm (OpImm << Src2Shift)
151 #define Src2ES (OpES << Src2Shift)
152 #define Src2CS (OpCS << Src2Shift)
153 #define Src2SS (OpSS << Src2Shift)
154 #define Src2DS (OpDS << Src2Shift)
155 #define Src2FS (OpFS << Src2Shift)
156 #define Src2GS (OpGS << Src2Shift)
157 #define Src2Mask (OpMask << Src2Shift)
158 #define Mmx ((u64)1 << 40) /* MMX Vector instruction */
159 #define Aligned ((u64)1 << 41) /* Explicitly aligned (e.g. MOVDQA) */
160 #define Unaligned ((u64)1 << 42) /* Explicitly unaligned (e.g. MOVDQU) */
161 #define Avx ((u64)1 << 43) /* Advanced Vector Extensions */
162 #define Fastop ((u64)1 << 44) /* Use opcode::u.fastop */
163 #define NoWrite ((u64)1 << 45) /* No writeback */
164 #define SrcWrite ((u64)1 << 46) /* Write back src operand */
165 #define NoMod ((u64)1 << 47) /* Mod field is ignored */
166 #define Intercept ((u64)1 << 48) /* Has valid intercept field */
167 #define CheckPerm ((u64)1 << 49) /* Has valid check_perm field */
168 #define NoBigReal ((u64)1 << 50) /* No big real mode */
169 #define PrivUD ((u64)1 << 51) /* #UD instead of #GP on CPL > 0 */
170 #define NearBranch ((u64)1 << 52) /* Near branches */
171 #define No16 ((u64)1 << 53) /* No 16 bit operand */
172
173 #define DstXacc (DstAccLo | SrcAccHi | SrcWrite)
174
175 #define X2(x...) x, x
176 #define X3(x...) X2(x), x
177 #define X4(x...) X2(x), X2(x)
178 #define X5(x...) X4(x), x
179 #define X6(x...) X4(x), X2(x)
180 #define X7(x...) X4(x), X3(x)
181 #define X8(x...) X4(x), X4(x)
182 #define X16(x...) X8(x), X8(x)
183
184 #define NR_FASTOP (ilog2(sizeof(ulong)) + 1)
185 #define FASTOP_SIZE 8
186
187 /*
188 * fastop functions have a special calling convention:
189 *
190 * dst: rax (in/out)
191 * src: rdx (in/out)
192 * src2: rcx (in)
193 * flags: rflags (in/out)
194 * ex: rsi (in:fastop pointer, out:zero if exception)
195 *
196 * Moreover, they are all exactly FASTOP_SIZE bytes long, so functions for
197 * different operand sizes can be reached by calculation, rather than a jump
198 * table (which would be bigger than the code).
199 *
200 * fastop functions are declared as taking a never-defined fastop parameter,
201 * so they can't be called from C directly.
202 */
203
204 struct fastop;
205
206 struct opcode {
207 u64 flags : 56;
208 u64 intercept : 8;
209 union {
210 int (*execute)(struct x86_emulate_ctxt *ctxt);
211 const struct opcode *group;
212 const struct group_dual *gdual;
213 const struct gprefix *gprefix;
214 const struct escape *esc;
215 const struct instr_dual *idual;
216 void (*fastop)(struct fastop *fake);
217 } u;
218 int (*check_perm)(struct x86_emulate_ctxt *ctxt);
219 };
220
221 struct group_dual {
222 struct opcode mod012[8];
223 struct opcode mod3[8];
224 };
225
226 struct gprefix {
227 struct opcode pfx_no;
228 struct opcode pfx_66;
229 struct opcode pfx_f2;
230 struct opcode pfx_f3;
231 };
232
233 struct escape {
234 struct opcode op[8];
235 struct opcode high[64];
236 };
237
238 struct instr_dual {
239 struct opcode mod012;
240 struct opcode mod3;
241 };
242
243 /* EFLAGS bit definitions. */
244 #define EFLG_ID (1<<21)
245 #define EFLG_VIP (1<<20)
246 #define EFLG_VIF (1<<19)
247 #define EFLG_AC (1<<18)
248 #define EFLG_VM (1<<17)
249 #define EFLG_RF (1<<16)
250 #define EFLG_IOPL (3<<12)
251 #define EFLG_NT (1<<14)
252 #define EFLG_OF (1<<11)
253 #define EFLG_DF (1<<10)
254 #define EFLG_IF (1<<9)
255 #define EFLG_TF (1<<8)
256 #define EFLG_SF (1<<7)
257 #define EFLG_ZF (1<<6)
258 #define EFLG_AF (1<<4)
259 #define EFLG_PF (1<<2)
260 #define EFLG_CF (1<<0)
261
262 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a
263 #define EFLG_RESERVED_ONE_MASK 2
264
265 static ulong reg_read(struct x86_emulate_ctxt *ctxt, unsigned nr)
266 {
267 if (!(ctxt->regs_valid & (1 << nr))) {
268 ctxt->regs_valid |= 1 << nr;
269 ctxt->_regs[nr] = ctxt->ops->read_gpr(ctxt, nr);
270 }
271 return ctxt->_regs[nr];
272 }
273
274 static ulong *reg_write(struct x86_emulate_ctxt *ctxt, unsigned nr)
275 {
276 ctxt->regs_valid |= 1 << nr;
277 ctxt->regs_dirty |= 1 << nr;
278 return &ctxt->_regs[nr];
279 }
280
281 static ulong *reg_rmw(struct x86_emulate_ctxt *ctxt, unsigned nr)
282 {
283 reg_read(ctxt, nr);
284 return reg_write(ctxt, nr);
285 }
286
287 static void writeback_registers(struct x86_emulate_ctxt *ctxt)
288 {
289 unsigned reg;
290
291 for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16)
292 ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]);
293 }
294
295 static void invalidate_registers(struct x86_emulate_ctxt *ctxt)
296 {
297 ctxt->regs_dirty = 0;
298 ctxt->regs_valid = 0;
299 }
300
301 /*
302 * These EFLAGS bits are restored from saved value during emulation, and
303 * any changes are written back to the saved value after emulation.
304 */
305 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
306
307 #ifdef CONFIG_X86_64
308 #define ON64(x) x
309 #else
310 #define ON64(x)
311 #endif
312
313 static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *));
314
315 #define FOP_ALIGN ".align " __stringify(FASTOP_SIZE) " \n\t"
316 #define FOP_RET "ret \n\t"
317
318 #define FOP_START(op) \
319 extern void em_##op(struct fastop *fake); \
320 asm(".pushsection .text, \"ax\" \n\t" \
321 ".global em_" #op " \n\t" \
322 FOP_ALIGN \
323 "em_" #op ": \n\t"
324
325 #define FOP_END \
326 ".popsection")
327
328 #define FOPNOP() FOP_ALIGN FOP_RET
329
330 #define FOP1E(op, dst) \
331 FOP_ALIGN "10: " #op " %" #dst " \n\t" FOP_RET
332
333 #define FOP1EEX(op, dst) \
334 FOP1E(op, dst) _ASM_EXTABLE(10b, kvm_fastop_exception)
335
336 #define FASTOP1(op) \
337 FOP_START(op) \
338 FOP1E(op##b, al) \
339 FOP1E(op##w, ax) \
340 FOP1E(op##l, eax) \
341 ON64(FOP1E(op##q, rax)) \
342 FOP_END
343
344 /* 1-operand, using src2 (for MUL/DIV r/m) */
345 #define FASTOP1SRC2(op, name) \
346 FOP_START(name) \
347 FOP1E(op, cl) \
348 FOP1E(op, cx) \
349 FOP1E(op, ecx) \
350 ON64(FOP1E(op, rcx)) \
351 FOP_END
352
353 /* 1-operand, using src2 (for MUL/DIV r/m), with exceptions */
354 #define FASTOP1SRC2EX(op, name) \
355 FOP_START(name) \
356 FOP1EEX(op, cl) \
357 FOP1EEX(op, cx) \
358 FOP1EEX(op, ecx) \
359 ON64(FOP1EEX(op, rcx)) \
360 FOP_END
361
362 #define FOP2E(op, dst, src) \
363 FOP_ALIGN #op " %" #src ", %" #dst " \n\t" FOP_RET
364
365 #define FASTOP2(op) \
366 FOP_START(op) \
367 FOP2E(op##b, al, dl) \
368 FOP2E(op##w, ax, dx) \
369 FOP2E(op##l, eax, edx) \
370 ON64(FOP2E(op##q, rax, rdx)) \
371 FOP_END
372
373 /* 2 operand, word only */
374 #define FASTOP2W(op) \
375 FOP_START(op) \
376 FOPNOP() \
377 FOP2E(op##w, ax, dx) \
378 FOP2E(op##l, eax, edx) \
379 ON64(FOP2E(op##q, rax, rdx)) \
380 FOP_END
381
382 /* 2 operand, src is CL */
383 #define FASTOP2CL(op) \
384 FOP_START(op) \
385 FOP2E(op##b, al, cl) \
386 FOP2E(op##w, ax, cl) \
387 FOP2E(op##l, eax, cl) \
388 ON64(FOP2E(op##q, rax, cl)) \
389 FOP_END
390
391 /* 2 operand, src and dest are reversed */
392 #define FASTOP2R(op, name) \
393 FOP_START(name) \
394 FOP2E(op##b, dl, al) \
395 FOP2E(op##w, dx, ax) \
396 FOP2E(op##l, edx, eax) \
397 ON64(FOP2E(op##q, rdx, rax)) \
398 FOP_END
399
400 #define FOP3E(op, dst, src, src2) \
401 FOP_ALIGN #op " %" #src2 ", %" #src ", %" #dst " \n\t" FOP_RET
402
403 /* 3-operand, word-only, src2=cl */
404 #define FASTOP3WCL(op) \
405 FOP_START(op) \
406 FOPNOP() \
407 FOP3E(op##w, ax, dx, cl) \
408 FOP3E(op##l, eax, edx, cl) \
409 ON64(FOP3E(op##q, rax, rdx, cl)) \
410 FOP_END
411
412 /* Special case for SETcc - 1 instruction per cc */
413 #define FOP_SETCC(op) ".align 4; " #op " %al; ret \n\t"
414
415 asm(".global kvm_fastop_exception \n"
416 "kvm_fastop_exception: xor %esi, %esi; ret");
417
418 FOP_START(setcc)
419 FOP_SETCC(seto)
420 FOP_SETCC(setno)
421 FOP_SETCC(setc)
422 FOP_SETCC(setnc)
423 FOP_SETCC(setz)
424 FOP_SETCC(setnz)
425 FOP_SETCC(setbe)
426 FOP_SETCC(setnbe)
427 FOP_SETCC(sets)
428 FOP_SETCC(setns)
429 FOP_SETCC(setp)
430 FOP_SETCC(setnp)
431 FOP_SETCC(setl)
432 FOP_SETCC(setnl)
433 FOP_SETCC(setle)
434 FOP_SETCC(setnle)
435 FOP_END;
436
437 FOP_START(salc) "pushf; sbb %al, %al; popf \n\t" FOP_RET
438 FOP_END;
439
440 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
441 enum x86_intercept intercept,
442 enum x86_intercept_stage stage)
443 {
444 struct x86_instruction_info info = {
445 .intercept = intercept,
446 .rep_prefix = ctxt->rep_prefix,
447 .modrm_mod = ctxt->modrm_mod,
448 .modrm_reg = ctxt->modrm_reg,
449 .modrm_rm = ctxt->modrm_rm,
450 .src_val = ctxt->src.val64,
451 .dst_val = ctxt->dst.val64,
452 .src_bytes = ctxt->src.bytes,
453 .dst_bytes = ctxt->dst.bytes,
454 .ad_bytes = ctxt->ad_bytes,
455 .next_rip = ctxt->eip,
456 };
457
458 return ctxt->ops->intercept(ctxt, &info, stage);
459 }
460
461 static void assign_masked(ulong *dest, ulong src, ulong mask)
462 {
463 *dest = (*dest & ~mask) | (src & mask);
464 }
465
466 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
467 {
468 return (1UL << (ctxt->ad_bytes << 3)) - 1;
469 }
470
471 static ulong stack_mask(struct x86_emulate_ctxt *ctxt)
472 {
473 u16 sel;
474 struct desc_struct ss;
475
476 if (ctxt->mode == X86EMUL_MODE_PROT64)
477 return ~0UL;
478 ctxt->ops->get_segment(ctxt, &sel, &ss, NULL, VCPU_SREG_SS);
479 return ~0U >> ((ss.d ^ 1) * 16); /* d=0: 0xffff; d=1: 0xffffffff */
480 }
481
482 static int stack_size(struct x86_emulate_ctxt *ctxt)
483 {
484 return (__fls(stack_mask(ctxt)) + 1) >> 3;
485 }
486
487 /* Access/update address held in a register, based on addressing mode. */
488 static inline unsigned long
489 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg)
490 {
491 if (ctxt->ad_bytes == sizeof(unsigned long))
492 return reg;
493 else
494 return reg & ad_mask(ctxt);
495 }
496
497 static inline unsigned long
498 register_address(struct x86_emulate_ctxt *ctxt, int reg)
499 {
500 return address_mask(ctxt, reg_read(ctxt, reg));
501 }
502
503 static void masked_increment(ulong *reg, ulong mask, int inc)
504 {
505 assign_masked(reg, *reg + inc, mask);
506 }
507
508 static inline void
509 register_address_increment(struct x86_emulate_ctxt *ctxt, int reg, int inc)
510 {
511 ulong mask;
512
513 if (ctxt->ad_bytes == sizeof(unsigned long))
514 mask = ~0UL;
515 else
516 mask = ad_mask(ctxt);
517 masked_increment(reg_rmw(ctxt, reg), mask, inc);
518 }
519
520 static void rsp_increment(struct x86_emulate_ctxt *ctxt, int inc)
521 {
522 masked_increment(reg_rmw(ctxt, VCPU_REGS_RSP), stack_mask(ctxt), inc);
523 }
524
525 static u32 desc_limit_scaled(struct desc_struct *desc)
526 {
527 u32 limit = get_desc_limit(desc);
528
529 return desc->g ? (limit << 12) | 0xfff : limit;
530 }
531
532 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
533 {
534 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
535 return 0;
536
537 return ctxt->ops->get_cached_segment_base(ctxt, seg);
538 }
539
540 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
541 u32 error, bool valid)
542 {
543 WARN_ON(vec > 0x1f);
544 ctxt->exception.vector = vec;
545 ctxt->exception.error_code = error;
546 ctxt->exception.error_code_valid = valid;
547 return X86EMUL_PROPAGATE_FAULT;
548 }
549
550 static int emulate_db(struct x86_emulate_ctxt *ctxt)
551 {
552 return emulate_exception(ctxt, DB_VECTOR, 0, false);
553 }
554
555 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
556 {
557 return emulate_exception(ctxt, GP_VECTOR, err, true);
558 }
559
560 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err)
561 {
562 return emulate_exception(ctxt, SS_VECTOR, err, true);
563 }
564
565 static int emulate_ud(struct x86_emulate_ctxt *ctxt)
566 {
567 return emulate_exception(ctxt, UD_VECTOR, 0, false);
568 }
569
570 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)
571 {
572 return emulate_exception(ctxt, TS_VECTOR, err, true);
573 }
574
575 static int emulate_de(struct x86_emulate_ctxt *ctxt)
576 {
577 return emulate_exception(ctxt, DE_VECTOR, 0, false);
578 }
579
580 static int emulate_nm(struct x86_emulate_ctxt *ctxt)
581 {
582 return emulate_exception(ctxt, NM_VECTOR, 0, false);
583 }
584
585 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
586 {
587 u16 selector;
588 struct desc_struct desc;
589
590 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg);
591 return selector;
592 }
593
594 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector,
595 unsigned seg)
596 {
597 u16 dummy;
598 u32 base3;
599 struct desc_struct desc;
600
601 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg);
602 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg);
603 }
604
605 /*
606 * x86 defines three classes of vector instructions: explicitly
607 * aligned, explicitly unaligned, and the rest, which change behaviour
608 * depending on whether they're AVX encoded or not.
609 *
610 * Also included is CMPXCHG16B which is not a vector instruction, yet it is
611 * subject to the same check.
612 */
613 static bool insn_aligned(struct x86_emulate_ctxt *ctxt, unsigned size)
614 {
615 if (likely(size < 16))
616 return false;
617
618 if (ctxt->d & Aligned)
619 return true;
620 else if (ctxt->d & Unaligned)
621 return false;
622 else if (ctxt->d & Avx)
623 return false;
624 else
625 return true;
626 }
627
628 static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
629 struct segmented_address addr,
630 unsigned *max_size, unsigned size,
631 bool write, bool fetch,
632 enum x86emul_mode mode, ulong *linear)
633 {
634 struct desc_struct desc;
635 bool usable;
636 ulong la;
637 u32 lim;
638 u16 sel;
639
640 la = seg_base(ctxt, addr.seg) + addr.ea;
641 *max_size = 0;
642 switch (mode) {
643 case X86EMUL_MODE_PROT64:
644 if (is_noncanonical_address(la))
645 goto bad;
646
647 *max_size = min_t(u64, ~0u, (1ull << 48) - la);
648 if (size > *max_size)
649 goto bad;
650 break;
651 default:
652 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
653 addr.seg);
654 if (!usable)
655 goto bad;
656 /* code segment in protected mode or read-only data segment */
657 if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8))
658 || !(desc.type & 2)) && write)
659 goto bad;
660 /* unreadable code segment */
661 if (!fetch && (desc.type & 8) && !(desc.type & 2))
662 goto bad;
663 lim = desc_limit_scaled(&desc);
664 if (!(desc.type & 8) && (desc.type & 4)) {
665 /* expand-down segment */
666 if (addr.ea <= lim)
667 goto bad;
668 lim = desc.d ? 0xffffffff : 0xffff;
669 }
670 if (addr.ea > lim)
671 goto bad;
672 *max_size = min_t(u64, ~0u, (u64)lim + 1 - addr.ea);
673 if (size > *max_size)
674 goto bad;
675 la &= (u32)-1;
676 break;
677 }
678 if (insn_aligned(ctxt, size) && ((la & (size - 1)) != 0))
679 return emulate_gp(ctxt, 0);
680 *linear = la;
681 return X86EMUL_CONTINUE;
682 bad:
683 if (addr.seg == VCPU_SREG_SS)
684 return emulate_ss(ctxt, 0);
685 else
686 return emulate_gp(ctxt, 0);
687 }
688
689 static int linearize(struct x86_emulate_ctxt *ctxt,
690 struct segmented_address addr,
691 unsigned size, bool write,
692 ulong *linear)
693 {
694 unsigned max_size;
695 return __linearize(ctxt, addr, &max_size, size, write, false,
696 ctxt->mode, linear);
697 }
698
699 static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst,
700 enum x86emul_mode mode)
701 {
702 ulong linear;
703 int rc;
704 unsigned max_size;
705 struct segmented_address addr = { .seg = VCPU_SREG_CS,
706 .ea = dst };
707
708 if (ctxt->op_bytes != sizeof(unsigned long))
709 addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1);
710 rc = __linearize(ctxt, addr, &max_size, 1, false, true, mode, &linear);
711 if (rc == X86EMUL_CONTINUE)
712 ctxt->_eip = addr.ea;
713 return rc;
714 }
715
716 static inline int assign_eip_near(struct x86_emulate_ctxt *ctxt, ulong dst)
717 {
718 return assign_eip(ctxt, dst, ctxt->mode);
719 }
720
721 static int assign_eip_far(struct x86_emulate_ctxt *ctxt, ulong dst,
722 const struct desc_struct *cs_desc)
723 {
724 enum x86emul_mode mode = ctxt->mode;
725
726 #ifdef CONFIG_X86_64
727 if (ctxt->mode >= X86EMUL_MODE_PROT32 && cs_desc->l) {
728 u64 efer = 0;
729
730 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
731 if (efer & EFER_LMA)
732 mode = X86EMUL_MODE_PROT64;
733 }
734 #endif
735 if (mode == X86EMUL_MODE_PROT16 || mode == X86EMUL_MODE_PROT32)
736 mode = cs_desc->d ? X86EMUL_MODE_PROT32 : X86EMUL_MODE_PROT16;
737 return assign_eip(ctxt, dst, mode);
738 }
739
740 static inline int jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
741 {
742 return assign_eip_near(ctxt, ctxt->_eip + rel);
743 }
744
745 static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
746 struct segmented_address addr,
747 void *data,
748 unsigned size)
749 {
750 int rc;
751 ulong linear;
752
753 rc = linearize(ctxt, addr, size, false, &linear);
754 if (rc != X86EMUL_CONTINUE)
755 return rc;
756 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
757 }
758
759 /*
760 * Prefetch the remaining bytes of the instruction without crossing page
761 * boundary if they are not in fetch_cache yet.
762 */
763 static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
764 {
765 int rc;
766 unsigned size, max_size;
767 unsigned long linear;
768 int cur_size = ctxt->fetch.end - ctxt->fetch.data;
769 struct segmented_address addr = { .seg = VCPU_SREG_CS,
770 .ea = ctxt->eip + cur_size };
771
772 /*
773 * We do not know exactly how many bytes will be needed, and
774 * __linearize is expensive, so fetch as much as possible. We
775 * just have to avoid going beyond the 15 byte limit, the end
776 * of the segment, or the end of the page.
777 *
778 * __linearize is called with size 0 so that it does not do any
779 * boundary check itself. Instead, we use max_size to check
780 * against op_size.
781 */
782 rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode,
783 &linear);
784 if (unlikely(rc != X86EMUL_CONTINUE))
785 return rc;
786
787 size = min_t(unsigned, 15UL ^ cur_size, max_size);
788 size = min_t(unsigned, size, PAGE_SIZE - offset_in_page(linear));
789
790 /*
791 * One instruction can only straddle two pages,
792 * and one has been loaded at the beginning of
793 * x86_decode_insn. So, if not enough bytes
794 * still, we must have hit the 15-byte boundary.
795 */
796 if (unlikely(size < op_size))
797 return emulate_gp(ctxt, 0);
798
799 rc = ctxt->ops->fetch(ctxt, linear, ctxt->fetch.end,
800 size, &ctxt->exception);
801 if (unlikely(rc != X86EMUL_CONTINUE))
802 return rc;
803 ctxt->fetch.end += size;
804 return X86EMUL_CONTINUE;
805 }
806
807 static __always_inline int do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt,
808 unsigned size)
809 {
810 unsigned done_size = ctxt->fetch.end - ctxt->fetch.ptr;
811
812 if (unlikely(done_size < size))
813 return __do_insn_fetch_bytes(ctxt, size - done_size);
814 else
815 return X86EMUL_CONTINUE;
816 }
817
818 /* Fetch next part of the instruction being emulated. */
819 #define insn_fetch(_type, _ctxt) \
820 ({ _type _x; \
821 \
822 rc = do_insn_fetch_bytes(_ctxt, sizeof(_type)); \
823 if (rc != X86EMUL_CONTINUE) \
824 goto done; \
825 ctxt->_eip += sizeof(_type); \
826 _x = *(_type __aligned(1) *) ctxt->fetch.ptr; \
827 ctxt->fetch.ptr += sizeof(_type); \
828 _x; \
829 })
830
831 #define insn_fetch_arr(_arr, _size, _ctxt) \
832 ({ \
833 rc = do_insn_fetch_bytes(_ctxt, _size); \
834 if (rc != X86EMUL_CONTINUE) \
835 goto done; \
836 ctxt->_eip += (_size); \
837 memcpy(_arr, ctxt->fetch.ptr, _size); \
838 ctxt->fetch.ptr += (_size); \
839 })
840
841 /*
842 * Given the 'reg' portion of a ModRM byte, and a register block, return a
843 * pointer into the block that addresses the relevant register.
844 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
845 */
846 static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_reg,
847 int byteop)
848 {
849 void *p;
850 int highbyte_regs = (ctxt->rex_prefix == 0) && byteop;
851
852 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
853 p = (unsigned char *)reg_rmw(ctxt, modrm_reg & 3) + 1;
854 else
855 p = reg_rmw(ctxt, modrm_reg);
856 return p;
857 }
858
859 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
860 struct segmented_address addr,
861 u16 *size, unsigned long *address, int op_bytes)
862 {
863 int rc;
864
865 if (op_bytes == 2)
866 op_bytes = 3;
867 *address = 0;
868 rc = segmented_read_std(ctxt, addr, size, 2);
869 if (rc != X86EMUL_CONTINUE)
870 return rc;
871 addr.ea += 2;
872 rc = segmented_read_std(ctxt, addr, address, op_bytes);
873 return rc;
874 }
875
876 FASTOP2(add);
877 FASTOP2(or);
878 FASTOP2(adc);
879 FASTOP2(sbb);
880 FASTOP2(and);
881 FASTOP2(sub);
882 FASTOP2(xor);
883 FASTOP2(cmp);
884 FASTOP2(test);
885
886 FASTOP1SRC2(mul, mul_ex);
887 FASTOP1SRC2(imul, imul_ex);
888 FASTOP1SRC2EX(div, div_ex);
889 FASTOP1SRC2EX(idiv, idiv_ex);
890
891 FASTOP3WCL(shld);
892 FASTOP3WCL(shrd);
893
894 FASTOP2W(imul);
895
896 FASTOP1(not);
897 FASTOP1(neg);
898 FASTOP1(inc);
899 FASTOP1(dec);
900
901 FASTOP2CL(rol);
902 FASTOP2CL(ror);
903 FASTOP2CL(rcl);
904 FASTOP2CL(rcr);
905 FASTOP2CL(shl);
906 FASTOP2CL(shr);
907 FASTOP2CL(sar);
908
909 FASTOP2W(bsf);
910 FASTOP2W(bsr);
911 FASTOP2W(bt);
912 FASTOP2W(bts);
913 FASTOP2W(btr);
914 FASTOP2W(btc);
915
916 FASTOP2(xadd);
917
918 FASTOP2R(cmp, cmp_r);
919
920 static u8 test_cc(unsigned int condition, unsigned long flags)
921 {
922 u8 rc;
923 void (*fop)(void) = (void *)em_setcc + 4 * (condition & 0xf);
924
925 flags = (flags & EFLAGS_MASK) | X86_EFLAGS_IF;
926 asm("push %[flags]; popf; call *%[fastop]"
927 : "=a"(rc) : [fastop]"r"(fop), [flags]"r"(flags));
928 return rc;
929 }
930
931 static void fetch_register_operand(struct operand *op)
932 {
933 switch (op->bytes) {
934 case 1:
935 op->val = *(u8 *)op->addr.reg;
936 break;
937 case 2:
938 op->val = *(u16 *)op->addr.reg;
939 break;
940 case 4:
941 op->val = *(u32 *)op->addr.reg;
942 break;
943 case 8:
944 op->val = *(u64 *)op->addr.reg;
945 break;
946 }
947 }
948
949 static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
950 {
951 ctxt->ops->get_fpu(ctxt);
952 switch (reg) {
953 case 0: asm("movdqa %%xmm0, %0" : "=m"(*data)); break;
954 case 1: asm("movdqa %%xmm1, %0" : "=m"(*data)); break;
955 case 2: asm("movdqa %%xmm2, %0" : "=m"(*data)); break;
956 case 3: asm("movdqa %%xmm3, %0" : "=m"(*data)); break;
957 case 4: asm("movdqa %%xmm4, %0" : "=m"(*data)); break;
958 case 5: asm("movdqa %%xmm5, %0" : "=m"(*data)); break;
959 case 6: asm("movdqa %%xmm6, %0" : "=m"(*data)); break;
960 case 7: asm("movdqa %%xmm7, %0" : "=m"(*data)); break;
961 #ifdef CONFIG_X86_64
962 case 8: asm("movdqa %%xmm8, %0" : "=m"(*data)); break;
963 case 9: asm("movdqa %%xmm9, %0" : "=m"(*data)); break;
964 case 10: asm("movdqa %%xmm10, %0" : "=m"(*data)); break;
965 case 11: asm("movdqa %%xmm11, %0" : "=m"(*data)); break;
966 case 12: asm("movdqa %%xmm12, %0" : "=m"(*data)); break;
967 case 13: asm("movdqa %%xmm13, %0" : "=m"(*data)); break;
968 case 14: asm("movdqa %%xmm14, %0" : "=m"(*data)); break;
969 case 15: asm("movdqa %%xmm15, %0" : "=m"(*data)); break;
970 #endif
971 default: BUG();
972 }
973 ctxt->ops->put_fpu(ctxt);
974 }
975
976 static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
977 int reg)
978 {
979 ctxt->ops->get_fpu(ctxt);
980 switch (reg) {
981 case 0: asm("movdqa %0, %%xmm0" : : "m"(*data)); break;
982 case 1: asm("movdqa %0, %%xmm1" : : "m"(*data)); break;
983 case 2: asm("movdqa %0, %%xmm2" : : "m"(*data)); break;
984 case 3: asm("movdqa %0, %%xmm3" : : "m"(*data)); break;
985 case 4: asm("movdqa %0, %%xmm4" : : "m"(*data)); break;
986 case 5: asm("movdqa %0, %%xmm5" : : "m"(*data)); break;
987 case 6: asm("movdqa %0, %%xmm6" : : "m"(*data)); break;
988 case 7: asm("movdqa %0, %%xmm7" : : "m"(*data)); break;
989 #ifdef CONFIG_X86_64
990 case 8: asm("movdqa %0, %%xmm8" : : "m"(*data)); break;
991 case 9: asm("movdqa %0, %%xmm9" : : "m"(*data)); break;
992 case 10: asm("movdqa %0, %%xmm10" : : "m"(*data)); break;
993 case 11: asm("movdqa %0, %%xmm11" : : "m"(*data)); break;
994 case 12: asm("movdqa %0, %%xmm12" : : "m"(*data)); break;
995 case 13: asm("movdqa %0, %%xmm13" : : "m"(*data)); break;
996 case 14: asm("movdqa %0, %%xmm14" : : "m"(*data)); break;
997 case 15: asm("movdqa %0, %%xmm15" : : "m"(*data)); break;
998 #endif
999 default: BUG();
1000 }
1001 ctxt->ops->put_fpu(ctxt);
1002 }
1003
1004 static void read_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
1005 {
1006 ctxt->ops->get_fpu(ctxt);
1007 switch (reg) {
1008 case 0: asm("movq %%mm0, %0" : "=m"(*data)); break;
1009 case 1: asm("movq %%mm1, %0" : "=m"(*data)); break;
1010 case 2: asm("movq %%mm2, %0" : "=m"(*data)); break;
1011 case 3: asm("movq %%mm3, %0" : "=m"(*data)); break;
1012 case 4: asm("movq %%mm4, %0" : "=m"(*data)); break;
1013 case 5: asm("movq %%mm5, %0" : "=m"(*data)); break;
1014 case 6: asm("movq %%mm6, %0" : "=m"(*data)); break;
1015 case 7: asm("movq %%mm7, %0" : "=m"(*data)); break;
1016 default: BUG();
1017 }
1018 ctxt->ops->put_fpu(ctxt);
1019 }
1020
1021 static void write_mmx_reg(struct x86_emulate_ctxt *ctxt, u64 *data, int reg)
1022 {
1023 ctxt->ops->get_fpu(ctxt);
1024 switch (reg) {
1025 case 0: asm("movq %0, %%mm0" : : "m"(*data)); break;
1026 case 1: asm("movq %0, %%mm1" : : "m"(*data)); break;
1027 case 2: asm("movq %0, %%mm2" : : "m"(*data)); break;
1028 case 3: asm("movq %0, %%mm3" : : "m"(*data)); break;
1029 case 4: asm("movq %0, %%mm4" : : "m"(*data)); break;
1030 case 5: asm("movq %0, %%mm5" : : "m"(*data)); break;
1031 case 6: asm("movq %0, %%mm6" : : "m"(*data)); break;
1032 case 7: asm("movq %0, %%mm7" : : "m"(*data)); break;
1033 default: BUG();
1034 }
1035 ctxt->ops->put_fpu(ctxt);
1036 }
1037
1038 static int em_fninit(struct x86_emulate_ctxt *ctxt)
1039 {
1040 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1041 return emulate_nm(ctxt);
1042
1043 ctxt->ops->get_fpu(ctxt);
1044 asm volatile("fninit");
1045 ctxt->ops->put_fpu(ctxt);
1046 return X86EMUL_CONTINUE;
1047 }
1048
1049 static int em_fnstcw(struct x86_emulate_ctxt *ctxt)
1050 {
1051 u16 fcw;
1052
1053 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1054 return emulate_nm(ctxt);
1055
1056 ctxt->ops->get_fpu(ctxt);
1057 asm volatile("fnstcw %0": "+m"(fcw));
1058 ctxt->ops->put_fpu(ctxt);
1059
1060 /* force 2 byte destination */
1061 ctxt->dst.bytes = 2;
1062 ctxt->dst.val = fcw;
1063
1064 return X86EMUL_CONTINUE;
1065 }
1066
1067 static int em_fnstsw(struct x86_emulate_ctxt *ctxt)
1068 {
1069 u16 fsw;
1070
1071 if (ctxt->ops->get_cr(ctxt, 0) & (X86_CR0_TS | X86_CR0_EM))
1072 return emulate_nm(ctxt);
1073
1074 ctxt->ops->get_fpu(ctxt);
1075 asm volatile("fnstsw %0": "+m"(fsw));
1076 ctxt->ops->put_fpu(ctxt);
1077
1078 /* force 2 byte destination */
1079 ctxt->dst.bytes = 2;
1080 ctxt->dst.val = fsw;
1081
1082 return X86EMUL_CONTINUE;
1083 }
1084
1085 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
1086 struct operand *op)
1087 {
1088 unsigned reg = ctxt->modrm_reg;
1089
1090 if (!(ctxt->d & ModRM))
1091 reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3);
1092
1093 if (ctxt->d & Sse) {
1094 op->type = OP_XMM;
1095 op->bytes = 16;
1096 op->addr.xmm = reg;
1097 read_sse_reg(ctxt, &op->vec_val, reg);
1098 return;
1099 }
1100 if (ctxt->d & Mmx) {
1101 reg &= 7;
1102 op->type = OP_MM;
1103 op->bytes = 8;
1104 op->addr.mm = reg;
1105 return;
1106 }
1107
1108 op->type = OP_REG;
1109 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
1110 op->addr.reg = decode_register(ctxt, reg, ctxt->d & ByteOp);
1111
1112 fetch_register_operand(op);
1113 op->orig_val = op->val;
1114 }
1115
1116 static void adjust_modrm_seg(struct x86_emulate_ctxt *ctxt, int base_reg)
1117 {
1118 if (base_reg == VCPU_REGS_RSP || base_reg == VCPU_REGS_RBP)
1119 ctxt->modrm_seg = VCPU_SREG_SS;
1120 }
1121
1122 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
1123 struct operand *op)
1124 {
1125 u8 sib;
1126 int index_reg, base_reg, scale;
1127 int rc = X86EMUL_CONTINUE;
1128 ulong modrm_ea = 0;
1129
1130 ctxt->modrm_reg = ((ctxt->rex_prefix << 1) & 8); /* REX.R */
1131 index_reg = (ctxt->rex_prefix << 2) & 8; /* REX.X */
1132 base_reg = (ctxt->rex_prefix << 3) & 8; /* REX.B */
1133
1134 ctxt->modrm_mod = (ctxt->modrm & 0xc0) >> 6;
1135 ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3;
1136 ctxt->modrm_rm = base_reg | (ctxt->modrm & 0x07);
1137 ctxt->modrm_seg = VCPU_SREG_DS;
1138
1139 if (ctxt->modrm_mod == 3 || (ctxt->d & NoMod)) {
1140 op->type = OP_REG;
1141 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
1142 op->addr.reg = decode_register(ctxt, ctxt->modrm_rm,
1143 ctxt->d & ByteOp);
1144 if (ctxt->d & Sse) {
1145 op->type = OP_XMM;
1146 op->bytes = 16;
1147 op->addr.xmm = ctxt->modrm_rm;
1148 read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
1149 return rc;
1150 }
1151 if (ctxt->d & Mmx) {
1152 op->type = OP_MM;
1153 op->bytes = 8;
1154 op->addr.mm = ctxt->modrm_rm & 7;
1155 return rc;
1156 }
1157 fetch_register_operand(op);
1158 return rc;
1159 }
1160
1161 op->type = OP_MEM;
1162
1163 if (ctxt->ad_bytes == 2) {
1164 unsigned bx = reg_read(ctxt, VCPU_REGS_RBX);
1165 unsigned bp = reg_read(ctxt, VCPU_REGS_RBP);
1166 unsigned si = reg_read(ctxt, VCPU_REGS_RSI);
1167 unsigned di = reg_read(ctxt, VCPU_REGS_RDI);
1168
1169 /* 16-bit ModR/M decode. */
1170 switch (ctxt->modrm_mod) {
1171 case 0:
1172 if (ctxt->modrm_rm == 6)
1173 modrm_ea += insn_fetch(u16, ctxt);
1174 break;
1175 case 1:
1176 modrm_ea += insn_fetch(s8, ctxt);
1177 break;
1178 case 2:
1179 modrm_ea += insn_fetch(u16, ctxt);
1180 break;
1181 }
1182 switch (ctxt->modrm_rm) {
1183 case 0:
1184 modrm_ea += bx + si;
1185 break;
1186 case 1:
1187 modrm_ea += bx + di;
1188 break;
1189 case 2:
1190 modrm_ea += bp + si;
1191 break;
1192 case 3:
1193 modrm_ea += bp + di;
1194 break;
1195 case 4:
1196 modrm_ea += si;
1197 break;
1198 case 5:
1199 modrm_ea += di;
1200 break;
1201 case 6:
1202 if (ctxt->modrm_mod != 0)
1203 modrm_ea += bp;
1204 break;
1205 case 7:
1206 modrm_ea += bx;
1207 break;
1208 }
1209 if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 ||
1210 (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0))
1211 ctxt->modrm_seg = VCPU_SREG_SS;
1212 modrm_ea = (u16)modrm_ea;
1213 } else {
1214 /* 32/64-bit ModR/M decode. */
1215 if ((ctxt->modrm_rm & 7) == 4) {
1216 sib = insn_fetch(u8, ctxt);
1217 index_reg |= (sib >> 3) & 7;
1218 base_reg |= sib & 7;
1219 scale = sib >> 6;
1220
1221 if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0)
1222 modrm_ea += insn_fetch(s32, ctxt);
1223 else {
1224 modrm_ea += reg_read(ctxt, base_reg);
1225 adjust_modrm_seg(ctxt, base_reg);
1226 }
1227 if (index_reg != 4)
1228 modrm_ea += reg_read(ctxt, index_reg) << scale;
1229 } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) {
1230 modrm_ea += insn_fetch(s32, ctxt);
1231 if (ctxt->mode == X86EMUL_MODE_PROT64)
1232 ctxt->rip_relative = 1;
1233 } else {
1234 base_reg = ctxt->modrm_rm;
1235 modrm_ea += reg_read(ctxt, base_reg);
1236 adjust_modrm_seg(ctxt, base_reg);
1237 }
1238 switch (ctxt->modrm_mod) {
1239 case 1:
1240 modrm_ea += insn_fetch(s8, ctxt);
1241 break;
1242 case 2:
1243 modrm_ea += insn_fetch(s32, ctxt);
1244 break;
1245 }
1246 }
1247 op->addr.mem.ea = modrm_ea;
1248 if (ctxt->ad_bytes != 8)
1249 ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
1250
1251 done:
1252 return rc;
1253 }
1254
1255 static int decode_abs(struct x86_emulate_ctxt *ctxt,
1256 struct operand *op)
1257 {
1258 int rc = X86EMUL_CONTINUE;
1259
1260 op->type = OP_MEM;
1261 switch (ctxt->ad_bytes) {
1262 case 2:
1263 op->addr.mem.ea = insn_fetch(u16, ctxt);
1264 break;
1265 case 4:
1266 op->addr.mem.ea = insn_fetch(u32, ctxt);
1267 break;
1268 case 8:
1269 op->addr.mem.ea = insn_fetch(u64, ctxt);
1270 break;
1271 }
1272 done:
1273 return rc;
1274 }
1275
1276 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt)
1277 {
1278 long sv = 0, mask;
1279
1280 if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) {
1281 mask = ~((long)ctxt->dst.bytes * 8 - 1);
1282
1283 if (ctxt->src.bytes == 2)
1284 sv = (s16)ctxt->src.val & (s16)mask;
1285 else if (ctxt->src.bytes == 4)
1286 sv = (s32)ctxt->src.val & (s32)mask;
1287 else
1288 sv = (s64)ctxt->src.val & (s64)mask;
1289
1290 ctxt->dst.addr.mem.ea = address_mask(ctxt,
1291 ctxt->dst.addr.mem.ea + (sv >> 3));
1292 }
1293
1294 /* only subword offset */
1295 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
1296 }
1297
1298 static int read_emulated(struct x86_emulate_ctxt *ctxt,
1299 unsigned long addr, void *dest, unsigned size)
1300 {
1301 int rc;
1302 struct read_cache *mc = &ctxt->mem_read;
1303
1304 if (mc->pos < mc->end)
1305 goto read_cached;
1306
1307 WARN_ON((mc->end + size) >= sizeof(mc->data));
1308
1309 rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, size,
1310 &ctxt->exception);
1311 if (rc != X86EMUL_CONTINUE)
1312 return rc;
1313
1314 mc->end += size;
1315
1316 read_cached:
1317 memcpy(dest, mc->data + mc->pos, size);
1318 mc->pos += size;
1319 return X86EMUL_CONTINUE;
1320 }
1321
1322 static int segmented_read(struct x86_emulate_ctxt *ctxt,
1323 struct segmented_address addr,
1324 void *data,
1325 unsigned size)
1326 {
1327 int rc;
1328 ulong linear;
1329
1330 rc = linearize(ctxt, addr, size, false, &linear);
1331 if (rc != X86EMUL_CONTINUE)
1332 return rc;
1333 return read_emulated(ctxt, linear, data, size);
1334 }
1335
1336 static int segmented_write(struct x86_emulate_ctxt *ctxt,
1337 struct segmented_address addr,
1338 const void *data,
1339 unsigned size)
1340 {
1341 int rc;
1342 ulong linear;
1343
1344 rc = linearize(ctxt, addr, size, true, &linear);
1345 if (rc != X86EMUL_CONTINUE)
1346 return rc;
1347 return ctxt->ops->write_emulated(ctxt, linear, data, size,
1348 &ctxt->exception);
1349 }
1350
1351 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
1352 struct segmented_address addr,
1353 const void *orig_data, const void *data,
1354 unsigned size)
1355 {
1356 int rc;
1357 ulong linear;
1358
1359 rc = linearize(ctxt, addr, size, true, &linear);
1360 if (rc != X86EMUL_CONTINUE)
1361 return rc;
1362 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data,
1363 size, &ctxt->exception);
1364 }
1365
1366 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
1367 unsigned int size, unsigned short port,
1368 void *dest)
1369 {
1370 struct read_cache *rc = &ctxt->io_read;
1371
1372 if (rc->pos == rc->end) { /* refill pio read ahead */
1373 unsigned int in_page, n;
1374 unsigned int count = ctxt->rep_prefix ?
1375 address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) : 1;
1376 in_page = (ctxt->eflags & EFLG_DF) ?
1377 offset_in_page(reg_read(ctxt, VCPU_REGS_RDI)) :
1378 PAGE_SIZE - offset_in_page(reg_read(ctxt, VCPU_REGS_RDI));
1379 n = min3(in_page, (unsigned int)sizeof(rc->data) / size, count);
1380 if (n == 0)
1381 n = 1;
1382 rc->pos = rc->end = 0;
1383 if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n))
1384 return 0;
1385 rc->end = n * size;
1386 }
1387
1388 if (ctxt->rep_prefix && (ctxt->d & String) &&
1389 !(ctxt->eflags & EFLG_DF)) {
1390 ctxt->dst.data = rc->data + rc->pos;
1391 ctxt->dst.type = OP_MEM_STR;
1392 ctxt->dst.count = (rc->end - rc->pos) / size;
1393 rc->pos = rc->end;
1394 } else {
1395 memcpy(dest, rc->data + rc->pos, size);
1396 rc->pos += size;
1397 }
1398 return 1;
1399 }
1400
1401 static int read_interrupt_descriptor(struct x86_emulate_ctxt *ctxt,
1402 u16 index, struct desc_struct *desc)
1403 {
1404 struct desc_ptr dt;
1405 ulong addr;
1406
1407 ctxt->ops->get_idt(ctxt, &dt);
1408
1409 if (dt.size < index * 8 + 7)
1410 return emulate_gp(ctxt, index << 3 | 0x2);
1411
1412 addr = dt.address + index * 8;
1413 return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1414 &ctxt->exception);
1415 }
1416
1417 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
1418 u16 selector, struct desc_ptr *dt)
1419 {
1420 const struct x86_emulate_ops *ops = ctxt->ops;
1421 u32 base3 = 0;
1422
1423 if (selector & 1 << 2) {
1424 struct desc_struct desc;
1425 u16 sel;
1426
1427 memset (dt, 0, sizeof *dt);
1428 if (!ops->get_segment(ctxt, &sel, &desc, &base3,
1429 VCPU_SREG_LDTR))
1430 return;
1431
1432 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
1433 dt->address = get_desc_base(&desc) | ((u64)base3 << 32);
1434 } else
1435 ops->get_gdt(ctxt, dt);
1436 }
1437
1438 /* allowed just for 8 bytes segments */
1439 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1440 u16 selector, struct desc_struct *desc,
1441 ulong *desc_addr_p)
1442 {
1443 struct desc_ptr dt;
1444 u16 index = selector >> 3;
1445 ulong addr;
1446
1447 get_descriptor_table_ptr(ctxt, selector, &dt);
1448
1449 if (dt.size < index * 8 + 7)
1450 return emulate_gp(ctxt, selector & 0xfffc);
1451
1452 *desc_addr_p = addr = dt.address + index * 8;
1453 return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1454 &ctxt->exception);
1455 }
1456
1457 /* allowed just for 8 bytes segments */
1458 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1459 u16 selector, struct desc_struct *desc)
1460 {
1461 struct desc_ptr dt;
1462 u16 index = selector >> 3;
1463 ulong addr;
1464
1465 get_descriptor_table_ptr(ctxt, selector, &dt);
1466
1467 if (dt.size < index * 8 + 7)
1468 return emulate_gp(ctxt, selector & 0xfffc);
1469
1470 addr = dt.address + index * 8;
1471 return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,
1472 &ctxt->exception);
1473 }
1474
1475 /* Does not support long mode */
1476 static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1477 u16 selector, int seg, u8 cpl,
1478 bool in_task_switch,
1479 struct desc_struct *desc)
1480 {
1481 struct desc_struct seg_desc, old_desc;
1482 u8 dpl, rpl;
1483 unsigned err_vec = GP_VECTOR;
1484 u32 err_code = 0;
1485 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
1486 ulong desc_addr;
1487 int ret;
1488 u16 dummy;
1489 u32 base3 = 0;
1490
1491 memset(&seg_desc, 0, sizeof seg_desc);
1492
1493 if (ctxt->mode == X86EMUL_MODE_REAL) {
1494 /* set real mode segment descriptor (keep limit etc. for
1495 * unreal mode) */
1496 ctxt->ops->get_segment(ctxt, &dummy, &seg_desc, NULL, seg);
1497 set_desc_base(&seg_desc, selector << 4);
1498 goto load;
1499 } else if (seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86) {
1500 /* VM86 needs a clean new segment descriptor */
1501 set_desc_base(&seg_desc, selector << 4);
1502 set_desc_limit(&seg_desc, 0xffff);
1503 seg_desc.type = 3;
1504 seg_desc.p = 1;
1505 seg_desc.s = 1;
1506 seg_desc.dpl = 3;
1507 goto load;
1508 }
1509
1510 rpl = selector & 3;
1511
1512 /* NULL selector is not valid for TR, CS and SS (except for long mode) */
1513 if ((seg == VCPU_SREG_CS
1514 || (seg == VCPU_SREG_SS
1515 && (ctxt->mode != X86EMUL_MODE_PROT64 || rpl != cpl))
1516 || seg == VCPU_SREG_TR)
1517 && null_selector)
1518 goto exception;
1519
1520 /* TR should be in GDT only */
1521 if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
1522 goto exception;
1523
1524 if (null_selector) /* for NULL selector skip all following checks */
1525 goto load;
1526
1527 ret = read_segment_descriptor(ctxt, selector, &seg_desc, &desc_addr);
1528 if (ret != X86EMUL_CONTINUE)
1529 return ret;
1530
1531 err_code = selector & 0xfffc;
1532 err_vec = in_task_switch ? TS_VECTOR : GP_VECTOR;
1533
1534 /* can't load system descriptor into segment selector */
1535 if (seg <= VCPU_SREG_GS && !seg_desc.s)
1536 goto exception;
1537
1538 if (!seg_desc.p) {
1539 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
1540 goto exception;
1541 }
1542
1543 dpl = seg_desc.dpl;
1544
1545 switch (seg) {
1546 case VCPU_SREG_SS:
1547 /*
1548 * segment is not a writable data segment or segment
1549 * selector's RPL != CPL or segment selector's RPL != CPL
1550 */
1551 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
1552 goto exception;
1553 break;
1554 case VCPU_SREG_CS:
1555 if (!(seg_desc.type & 8))
1556 goto exception;
1557
1558 if (seg_desc.type & 4) {
1559 /* conforming */
1560 if (dpl > cpl)
1561 goto exception;
1562 } else {
1563 /* nonconforming */
1564 if (rpl > cpl || dpl != cpl)
1565 goto exception;
1566 }
1567 /* in long-mode d/b must be clear if l is set */
1568 if (seg_desc.d && seg_desc.l) {
1569 u64 efer = 0;
1570
1571 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
1572 if (efer & EFER_LMA)
1573 goto exception;
1574 }
1575
1576 /* CS(RPL) <- CPL */
1577 selector = (selector & 0xfffc) | cpl;
1578 break;
1579 case VCPU_SREG_TR:
1580 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1581 goto exception;
1582 old_desc = seg_desc;
1583 seg_desc.type |= 2; /* busy */
1584 ret = ctxt->ops->cmpxchg_emulated(ctxt, desc_addr, &old_desc, &seg_desc,
1585 sizeof(seg_desc), &ctxt->exception);
1586 if (ret != X86EMUL_CONTINUE)
1587 return ret;
1588 break;
1589 case VCPU_SREG_LDTR:
1590 if (seg_desc.s || seg_desc.type != 2)
1591 goto exception;
1592 break;
1593 default: /* DS, ES, FS, or GS */
1594 /*
1595 * segment is not a data or readable code segment or
1596 * ((segment is a data or nonconforming code segment)
1597 * and (both RPL and CPL > DPL))
1598 */
1599 if ((seg_desc.type & 0xa) == 0x8 ||
1600 (((seg_desc.type & 0xc) != 0xc) &&
1601 (rpl > dpl && cpl > dpl)))
1602 goto exception;
1603 break;
1604 }
1605
1606 if (seg_desc.s) {
1607 /* mark segment as accessed */
1608 seg_desc.type |= 1;
1609 ret = write_segment_descriptor(ctxt, selector, &seg_desc);
1610 if (ret != X86EMUL_CONTINUE)
1611 return ret;
1612 } else if (ctxt->mode == X86EMUL_MODE_PROT64) {
1613 ret = ctxt->ops->read_std(ctxt, desc_addr+8, &base3,
1614 sizeof(base3), &ctxt->exception);
1615 if (ret != X86EMUL_CONTINUE)
1616 return ret;
1617 if (is_noncanonical_address(get_desc_base(&seg_desc) |
1618 ((u64)base3 << 32)))
1619 return emulate_gp(ctxt, 0);
1620 }
1621 load:
1622 ctxt->ops->set_segment(ctxt, selector, &seg_desc, base3, seg);
1623 if (desc)
1624 *desc = seg_desc;
1625 return X86EMUL_CONTINUE;
1626 exception:
1627 return emulate_exception(ctxt, err_vec, err_code, true);
1628 }
1629
1630 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1631 u16 selector, int seg)
1632 {
1633 u8 cpl = ctxt->ops->cpl(ctxt);
1634 return __load_segment_descriptor(ctxt, selector, seg, cpl, false, NULL);
1635 }
1636
1637 static void write_register_operand(struct operand *op)
1638 {
1639 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
1640 switch (op->bytes) {
1641 case 1:
1642 *(u8 *)op->addr.reg = (u8)op->val;
1643 break;
1644 case 2:
1645 *(u16 *)op->addr.reg = (u16)op->val;
1646 break;
1647 case 4:
1648 *op->addr.reg = (u32)op->val;
1649 break; /* 64b: zero-extend */
1650 case 8:
1651 *op->addr.reg = op->val;
1652 break;
1653 }
1654 }
1655
1656 static int writeback(struct x86_emulate_ctxt *ctxt, struct operand *op)
1657 {
1658 switch (op->type) {
1659 case OP_REG:
1660 write_register_operand(op);
1661 break;
1662 case OP_MEM:
1663 if (ctxt->lock_prefix)
1664 return segmented_cmpxchg(ctxt,
1665 op->addr.mem,
1666 &op->orig_val,
1667 &op->val,
1668 op->bytes);
1669 else
1670 return segmented_write(ctxt,
1671 op->addr.mem,
1672 &op->val,
1673 op->bytes);
1674 break;
1675 case OP_MEM_STR:
1676 return segmented_write(ctxt,
1677 op->addr.mem,
1678 op->data,
1679 op->bytes * op->count);
1680 break;
1681 case OP_XMM:
1682 write_sse_reg(ctxt, &op->vec_val, op->addr.xmm);
1683 break;
1684 case OP_MM:
1685 write_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
1686 break;
1687 case OP_NONE:
1688 /* no writeback */
1689 break;
1690 default:
1691 break;
1692 }
1693 return X86EMUL_CONTINUE;
1694 }
1695
1696 static int push(struct x86_emulate_ctxt *ctxt, void *data, int bytes)
1697 {
1698 struct segmented_address addr;
1699
1700 rsp_increment(ctxt, -bytes);
1701 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt);
1702 addr.seg = VCPU_SREG_SS;
1703
1704 return segmented_write(ctxt, addr, data, bytes);
1705 }
1706
1707 static int em_push(struct x86_emulate_ctxt *ctxt)
1708 {
1709 /* Disable writeback. */
1710 ctxt->dst.type = OP_NONE;
1711 return push(ctxt, &ctxt->src.val, ctxt->op_bytes);
1712 }
1713
1714 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1715 void *dest, int len)
1716 {
1717 int rc;
1718 struct segmented_address addr;
1719
1720 addr.ea = reg_read(ctxt, VCPU_REGS_RSP) & stack_mask(ctxt);
1721 addr.seg = VCPU_SREG_SS;
1722 rc = segmented_read(ctxt, addr, dest, len);
1723 if (rc != X86EMUL_CONTINUE)
1724 return rc;
1725
1726 rsp_increment(ctxt, len);
1727 return rc;
1728 }
1729
1730 static int em_pop(struct x86_emulate_ctxt *ctxt)
1731 {
1732 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1733 }
1734
1735 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1736 void *dest, int len)
1737 {
1738 int rc;
1739 unsigned long val, change_mask;
1740 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1741 int cpl = ctxt->ops->cpl(ctxt);
1742
1743 rc = emulate_pop(ctxt, &val, len);
1744 if (rc != X86EMUL_CONTINUE)
1745 return rc;
1746
1747 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
1748 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_AC | EFLG_ID;
1749
1750 switch(ctxt->mode) {
1751 case X86EMUL_MODE_PROT64:
1752 case X86EMUL_MODE_PROT32:
1753 case X86EMUL_MODE_PROT16:
1754 if (cpl == 0)
1755 change_mask |= EFLG_IOPL;
1756 if (cpl <= iopl)
1757 change_mask |= EFLG_IF;
1758 break;
1759 case X86EMUL_MODE_VM86:
1760 if (iopl < 3)
1761 return emulate_gp(ctxt, 0);
1762 change_mask |= EFLG_IF;
1763 break;
1764 default: /* real mode */
1765 change_mask |= (EFLG_IOPL | EFLG_IF);
1766 break;
1767 }
1768
1769 *(unsigned long *)dest =
1770 (ctxt->eflags & ~change_mask) | (val & change_mask);
1771
1772 return rc;
1773 }
1774
1775 static int em_popf(struct x86_emulate_ctxt *ctxt)
1776 {
1777 ctxt->dst.type = OP_REG;
1778 ctxt->dst.addr.reg = &ctxt->eflags;
1779 ctxt->dst.bytes = ctxt->op_bytes;
1780 return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1781 }
1782
1783 static int em_enter(struct x86_emulate_ctxt *ctxt)
1784 {
1785 int rc;
1786 unsigned frame_size = ctxt->src.val;
1787 unsigned nesting_level = ctxt->src2.val & 31;
1788 ulong rbp;
1789
1790 if (nesting_level)
1791 return X86EMUL_UNHANDLEABLE;
1792
1793 rbp = reg_read(ctxt, VCPU_REGS_RBP);
1794 rc = push(ctxt, &rbp, stack_size(ctxt));
1795 if (rc != X86EMUL_CONTINUE)
1796 return rc;
1797 assign_masked(reg_rmw(ctxt, VCPU_REGS_RBP), reg_read(ctxt, VCPU_REGS_RSP),
1798 stack_mask(ctxt));
1799 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP),
1800 reg_read(ctxt, VCPU_REGS_RSP) - frame_size,
1801 stack_mask(ctxt));
1802 return X86EMUL_CONTINUE;
1803 }
1804
1805 static int em_leave(struct x86_emulate_ctxt *ctxt)
1806 {
1807 assign_masked(reg_rmw(ctxt, VCPU_REGS_RSP), reg_read(ctxt, VCPU_REGS_RBP),
1808 stack_mask(ctxt));
1809 return emulate_pop(ctxt, reg_rmw(ctxt, VCPU_REGS_RBP), ctxt->op_bytes);
1810 }
1811
1812 static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
1813 {
1814 int seg = ctxt->src2.val;
1815
1816 ctxt->src.val = get_segment_selector(ctxt, seg);
1817 if (ctxt->op_bytes == 4) {
1818 rsp_increment(ctxt, -2);
1819 ctxt->op_bytes = 2;
1820 }
1821
1822 return em_push(ctxt);
1823 }
1824
1825 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt)
1826 {
1827 int seg = ctxt->src2.val;
1828 unsigned long selector;
1829 int rc;
1830
1831 rc = emulate_pop(ctxt, &selector, ctxt->op_bytes);
1832 if (rc != X86EMUL_CONTINUE)
1833 return rc;
1834
1835 if (ctxt->modrm_reg == VCPU_SREG_SS)
1836 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
1837
1838 rc = load_segment_descriptor(ctxt, (u16)selector, seg);
1839 return rc;
1840 }
1841
1842 static int em_pusha(struct x86_emulate_ctxt *ctxt)
1843 {
1844 unsigned long old_esp = reg_read(ctxt, VCPU_REGS_RSP);
1845 int rc = X86EMUL_CONTINUE;
1846 int reg = VCPU_REGS_RAX;
1847
1848 while (reg <= VCPU_REGS_RDI) {
1849 (reg == VCPU_REGS_RSP) ?
1850 (ctxt->src.val = old_esp) : (ctxt->src.val = reg_read(ctxt, reg));
1851
1852 rc = em_push(ctxt);
1853 if (rc != X86EMUL_CONTINUE)
1854 return rc;
1855
1856 ++reg;
1857 }
1858
1859 return rc;
1860 }
1861
1862 static int em_pushf(struct x86_emulate_ctxt *ctxt)
1863 {
1864 ctxt->src.val = (unsigned long)ctxt->eflags & ~EFLG_VM;
1865 return em_push(ctxt);
1866 }
1867
1868 static int em_popa(struct x86_emulate_ctxt *ctxt)
1869 {
1870 int rc = X86EMUL_CONTINUE;
1871 int reg = VCPU_REGS_RDI;
1872
1873 while (reg >= VCPU_REGS_RAX) {
1874 if (reg == VCPU_REGS_RSP) {
1875 rsp_increment(ctxt, ctxt->op_bytes);
1876 --reg;
1877 }
1878
1879 rc = emulate_pop(ctxt, reg_rmw(ctxt, reg), ctxt->op_bytes);
1880 if (rc != X86EMUL_CONTINUE)
1881 break;
1882 --reg;
1883 }
1884 return rc;
1885 }
1886
1887 static int __emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1888 {
1889 const struct x86_emulate_ops *ops = ctxt->ops;
1890 int rc;
1891 struct desc_ptr dt;
1892 gva_t cs_addr;
1893 gva_t eip_addr;
1894 u16 cs, eip;
1895
1896 /* TODO: Add limit checks */
1897 ctxt->src.val = ctxt->eflags;
1898 rc = em_push(ctxt);
1899 if (rc != X86EMUL_CONTINUE)
1900 return rc;
1901
1902 ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC);
1903
1904 ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS);
1905 rc = em_push(ctxt);
1906 if (rc != X86EMUL_CONTINUE)
1907 return rc;
1908
1909 ctxt->src.val = ctxt->_eip;
1910 rc = em_push(ctxt);
1911 if (rc != X86EMUL_CONTINUE)
1912 return rc;
1913
1914 ops->get_idt(ctxt, &dt);
1915
1916 eip_addr = dt.address + (irq << 2);
1917 cs_addr = dt.address + (irq << 2) + 2;
1918
1919 rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);
1920 if (rc != X86EMUL_CONTINUE)
1921 return rc;
1922
1923 rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);
1924 if (rc != X86EMUL_CONTINUE)
1925 return rc;
1926
1927 rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS);
1928 if (rc != X86EMUL_CONTINUE)
1929 return rc;
1930
1931 ctxt->_eip = eip;
1932
1933 return rc;
1934 }
1935
1936 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1937 {
1938 int rc;
1939
1940 invalidate_registers(ctxt);
1941 rc = __emulate_int_real(ctxt, irq);
1942 if (rc == X86EMUL_CONTINUE)
1943 writeback_registers(ctxt);
1944 return rc;
1945 }
1946
1947 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq)
1948 {
1949 switch(ctxt->mode) {
1950 case X86EMUL_MODE_REAL:
1951 return __emulate_int_real(ctxt, irq);
1952 case X86EMUL_MODE_VM86:
1953 case X86EMUL_MODE_PROT16:
1954 case X86EMUL_MODE_PROT32:
1955 case X86EMUL_MODE_PROT64:
1956 default:
1957 /* Protected mode interrupts unimplemented yet */
1958 return X86EMUL_UNHANDLEABLE;
1959 }
1960 }
1961
1962 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
1963 {
1964 int rc = X86EMUL_CONTINUE;
1965 unsigned long temp_eip = 0;
1966 unsigned long temp_eflags = 0;
1967 unsigned long cs = 0;
1968 unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF |
1969 EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF |
1970 EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */
1971 unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP;
1972
1973 /* TODO: Add stack limit check */
1974
1975 rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes);
1976
1977 if (rc != X86EMUL_CONTINUE)
1978 return rc;
1979
1980 if (temp_eip & ~0xffff)
1981 return emulate_gp(ctxt, 0);
1982
1983 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
1984
1985 if (rc != X86EMUL_CONTINUE)
1986 return rc;
1987
1988 rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes);
1989
1990 if (rc != X86EMUL_CONTINUE)
1991 return rc;
1992
1993 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
1994
1995 if (rc != X86EMUL_CONTINUE)
1996 return rc;
1997
1998 ctxt->_eip = temp_eip;
1999
2000
2001 if (ctxt->op_bytes == 4)
2002 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
2003 else if (ctxt->op_bytes == 2) {
2004 ctxt->eflags &= ~0xffff;
2005 ctxt->eflags |= temp_eflags;
2006 }
2007
2008 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
2009 ctxt->eflags |= EFLG_RESERVED_ONE_MASK;
2010
2011 return rc;
2012 }
2013
2014 static int em_iret(struct x86_emulate_ctxt *ctxt)
2015 {
2016 switch(ctxt->mode) {
2017 case X86EMUL_MODE_REAL:
2018 return emulate_iret_real(ctxt);
2019 case X86EMUL_MODE_VM86:
2020 case X86EMUL_MODE_PROT16:
2021 case X86EMUL_MODE_PROT32:
2022 case X86EMUL_MODE_PROT64:
2023 default:
2024 /* iret from protected mode unimplemented yet */
2025 return X86EMUL_UNHANDLEABLE;
2026 }
2027 }
2028
2029 static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
2030 {
2031 int rc;
2032 unsigned short sel, old_sel;
2033 struct desc_struct old_desc, new_desc;
2034 const struct x86_emulate_ops *ops = ctxt->ops;
2035 u8 cpl = ctxt->ops->cpl(ctxt);
2036
2037 /* Assignment of RIP may only fail in 64-bit mode */
2038 if (ctxt->mode == X86EMUL_MODE_PROT64)
2039 ops->get_segment(ctxt, &old_sel, &old_desc, NULL,
2040 VCPU_SREG_CS);
2041
2042 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2043
2044 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, false,
2045 &new_desc);
2046 if (rc != X86EMUL_CONTINUE)
2047 return rc;
2048
2049 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc);
2050 if (rc != X86EMUL_CONTINUE) {
2051 WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
2052 /* assigning eip failed; restore the old cs */
2053 ops->set_segment(ctxt, old_sel, &old_desc, 0, VCPU_SREG_CS);
2054 return rc;
2055 }
2056 return rc;
2057 }
2058
2059 static int em_jmp_abs(struct x86_emulate_ctxt *ctxt)
2060 {
2061 return assign_eip_near(ctxt, ctxt->src.val);
2062 }
2063
2064 static int em_call_near_abs(struct x86_emulate_ctxt *ctxt)
2065 {
2066 int rc;
2067 long int old_eip;
2068
2069 old_eip = ctxt->_eip;
2070 rc = assign_eip_near(ctxt, ctxt->src.val);
2071 if (rc != X86EMUL_CONTINUE)
2072 return rc;
2073 ctxt->src.val = old_eip;
2074 rc = em_push(ctxt);
2075 return rc;
2076 }
2077
2078 static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt)
2079 {
2080 u64 old = ctxt->dst.orig_val64;
2081
2082 if (ctxt->dst.bytes == 16)
2083 return X86EMUL_UNHANDLEABLE;
2084
2085 if (((u32) (old >> 0) != (u32) reg_read(ctxt, VCPU_REGS_RAX)) ||
2086 ((u32) (old >> 32) != (u32) reg_read(ctxt, VCPU_REGS_RDX))) {
2087 *reg_write(ctxt, VCPU_REGS_RAX) = (u32) (old >> 0);
2088 *reg_write(ctxt, VCPU_REGS_RDX) = (u32) (old >> 32);
2089 ctxt->eflags &= ~EFLG_ZF;
2090 } else {
2091 ctxt->dst.val64 = ((u64)reg_read(ctxt, VCPU_REGS_RCX) << 32) |
2092 (u32) reg_read(ctxt, VCPU_REGS_RBX);
2093
2094 ctxt->eflags |= EFLG_ZF;
2095 }
2096 return X86EMUL_CONTINUE;
2097 }
2098
2099 static int em_ret(struct x86_emulate_ctxt *ctxt)
2100 {
2101 int rc;
2102 unsigned long eip;
2103
2104 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
2105 if (rc != X86EMUL_CONTINUE)
2106 return rc;
2107
2108 return assign_eip_near(ctxt, eip);
2109 }
2110
2111 static int em_ret_far(struct x86_emulate_ctxt *ctxt)
2112 {
2113 int rc;
2114 unsigned long eip, cs;
2115 u16 old_cs;
2116 int cpl = ctxt->ops->cpl(ctxt);
2117 struct desc_struct old_desc, new_desc;
2118 const struct x86_emulate_ops *ops = ctxt->ops;
2119
2120 if (ctxt->mode == X86EMUL_MODE_PROT64)
2121 ops->get_segment(ctxt, &old_cs, &old_desc, NULL,
2122 VCPU_SREG_CS);
2123
2124 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
2125 if (rc != X86EMUL_CONTINUE)
2126 return rc;
2127 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
2128 if (rc != X86EMUL_CONTINUE)
2129 return rc;
2130 /* Outer-privilege level return is not implemented */
2131 if (ctxt->mode >= X86EMUL_MODE_PROT16 && (cs & 3) > cpl)
2132 return X86EMUL_UNHANDLEABLE;
2133 rc = __load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS, 0, false,
2134 &new_desc);
2135 if (rc != X86EMUL_CONTINUE)
2136 return rc;
2137 rc = assign_eip_far(ctxt, eip, &new_desc);
2138 if (rc != X86EMUL_CONTINUE) {
2139 WARN_ON(ctxt->mode != X86EMUL_MODE_PROT64);
2140 ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
2141 }
2142 return rc;
2143 }
2144
2145 static int em_ret_far_imm(struct x86_emulate_ctxt *ctxt)
2146 {
2147 int rc;
2148
2149 rc = em_ret_far(ctxt);
2150 if (rc != X86EMUL_CONTINUE)
2151 return rc;
2152 rsp_increment(ctxt, ctxt->src.val);
2153 return X86EMUL_CONTINUE;
2154 }
2155
2156 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
2157 {
2158 /* Save real source value, then compare EAX against destination. */
2159 ctxt->dst.orig_val = ctxt->dst.val;
2160 ctxt->dst.val = reg_read(ctxt, VCPU_REGS_RAX);
2161 ctxt->src.orig_val = ctxt->src.val;
2162 ctxt->src.val = ctxt->dst.orig_val;
2163 fastop(ctxt, em_cmp);
2164
2165 if (ctxt->eflags & EFLG_ZF) {
2166 /* Success: write back to memory. */
2167 ctxt->dst.val = ctxt->src.orig_val;
2168 } else {
2169 /* Failure: write the value we saw to EAX. */
2170 ctxt->dst.type = OP_REG;
2171 ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
2172 ctxt->dst.val = ctxt->dst.orig_val;
2173 }
2174 return X86EMUL_CONTINUE;
2175 }
2176
2177 static int em_lseg(struct x86_emulate_ctxt *ctxt)
2178 {
2179 int seg = ctxt->src2.val;
2180 unsigned short sel;
2181 int rc;
2182
2183 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2184
2185 rc = load_segment_descriptor(ctxt, sel, seg);
2186 if (rc != X86EMUL_CONTINUE)
2187 return rc;
2188
2189 ctxt->dst.val = ctxt->src.val;
2190 return rc;
2191 }
2192
2193 static void
2194 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
2195 struct desc_struct *cs, struct desc_struct *ss)
2196 {
2197 cs->l = 0; /* will be adjusted later */
2198 set_desc_base(cs, 0); /* flat segment */
2199 cs->g = 1; /* 4kb granularity */
2200 set_desc_limit(cs, 0xfffff); /* 4GB limit */
2201 cs->type = 0x0b; /* Read, Execute, Accessed */
2202 cs->s = 1;
2203 cs->dpl = 0; /* will be adjusted later */
2204 cs->p = 1;
2205 cs->d = 1;
2206 cs->avl = 0;
2207
2208 set_desc_base(ss, 0); /* flat segment */
2209 set_desc_limit(ss, 0xfffff); /* 4GB limit */
2210 ss->g = 1; /* 4kb granularity */
2211 ss->s = 1;
2212 ss->type = 0x03; /* Read/Write, Accessed */
2213 ss->d = 1; /* 32bit stack segment */
2214 ss->dpl = 0;
2215 ss->p = 1;
2216 ss->l = 0;
2217 ss->avl = 0;
2218 }
2219
2220 static bool vendor_intel(struct x86_emulate_ctxt *ctxt)
2221 {
2222 u32 eax, ebx, ecx, edx;
2223
2224 eax = ecx = 0;
2225 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2226 return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx
2227 && ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx
2228 && edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx;
2229 }
2230
2231 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
2232 {
2233 const struct x86_emulate_ops *ops = ctxt->ops;
2234 u32 eax, ebx, ecx, edx;
2235
2236 /*
2237 * syscall should always be enabled in longmode - so only become
2238 * vendor specific (cpuid) if other modes are active...
2239 */
2240 if (ctxt->mode == X86EMUL_MODE_PROT64)
2241 return true;
2242
2243 eax = 0x00000000;
2244 ecx = 0x00000000;
2245 ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
2246 /*
2247 * Intel ("GenuineIntel")
2248 * remark: Intel CPUs only support "syscall" in 64bit
2249 * longmode. Also an 64bit guest with a
2250 * 32bit compat-app running will #UD !! While this
2251 * behaviour can be fixed (by emulating) into AMD
2252 * response - CPUs of AMD can't behave like Intel.
2253 */
2254 if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx &&
2255 ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx &&
2256 edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx)
2257 return false;
2258
2259 /* AMD ("AuthenticAMD") */
2260 if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx &&
2261 ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx &&
2262 edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
2263 return true;
2264
2265 /* AMD ("AMDisbetter!") */
2266 if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx &&
2267 ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx &&
2268 edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
2269 return true;
2270
2271 /* default: (not Intel, not AMD), apply Intel's stricter rules... */
2272 return false;
2273 }
2274
2275 static int em_syscall(struct x86_emulate_ctxt *ctxt)
2276 {
2277 const struct x86_emulate_ops *ops = ctxt->ops;
2278 struct desc_struct cs, ss;
2279 u64 msr_data;
2280 u16 cs_sel, ss_sel;
2281 u64 efer = 0;
2282
2283 /* syscall is not available in real mode */
2284 if (ctxt->mode == X86EMUL_MODE_REAL ||
2285 ctxt->mode == X86EMUL_MODE_VM86)
2286 return emulate_ud(ctxt);
2287
2288 if (!(em_syscall_is_enabled(ctxt)))
2289 return emulate_ud(ctxt);
2290
2291 ops->get_msr(ctxt, MSR_EFER, &efer);
2292 setup_syscalls_segments(ctxt, &cs, &ss);
2293
2294 if (!(efer & EFER_SCE))
2295 return emulate_ud(ctxt);
2296
2297 ops->get_msr(ctxt, MSR_STAR, &msr_data);
2298 msr_data >>= 32;
2299 cs_sel = (u16)(msr_data & 0xfffc);
2300 ss_sel = (u16)(msr_data + 8);
2301
2302 if (efer & EFER_LMA) {
2303 cs.d = 0;
2304 cs.l = 1;
2305 }
2306 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2307 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2308
2309 *reg_write(ctxt, VCPU_REGS_RCX) = ctxt->_eip;
2310 if (efer & EFER_LMA) {
2311 #ifdef CONFIG_X86_64
2312 *reg_write(ctxt, VCPU_REGS_R11) = ctxt->eflags;
2313
2314 ops->get_msr(ctxt,
2315 ctxt->mode == X86EMUL_MODE_PROT64 ?
2316 MSR_LSTAR : MSR_CSTAR, &msr_data);
2317 ctxt->_eip = msr_data;
2318
2319 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data);
2320 ctxt->eflags &= ~msr_data;
2321 ctxt->eflags |= EFLG_RESERVED_ONE_MASK;
2322 #endif
2323 } else {
2324 /* legacy mode */
2325 ops->get_msr(ctxt, MSR_STAR, &msr_data);
2326 ctxt->_eip = (u32)msr_data;
2327
2328 ctxt->eflags &= ~(EFLG_VM | EFLG_IF);
2329 }
2330
2331 return X86EMUL_CONTINUE;
2332 }
2333
2334 static int em_sysenter(struct x86_emulate_ctxt *ctxt)
2335 {
2336 const struct x86_emulate_ops *ops = ctxt->ops;
2337 struct desc_struct cs, ss;
2338 u64 msr_data;
2339 u16 cs_sel, ss_sel;
2340 u64 efer = 0;
2341
2342 ops->get_msr(ctxt, MSR_EFER, &efer);
2343 /* inject #GP if in real mode */
2344 if (ctxt->mode == X86EMUL_MODE_REAL)
2345 return emulate_gp(ctxt, 0);
2346
2347 /*
2348 * Not recognized on AMD in compat mode (but is recognized in legacy
2349 * mode).
2350 */
2351 if ((ctxt->mode == X86EMUL_MODE_PROT32) && (efer & EFER_LMA)
2352 && !vendor_intel(ctxt))
2353 return emulate_ud(ctxt);
2354
2355 /* sysenter/sysexit have not been tested in 64bit mode. */
2356 if (ctxt->mode == X86EMUL_MODE_PROT64)
2357 return X86EMUL_UNHANDLEABLE;
2358
2359 setup_syscalls_segments(ctxt, &cs, &ss);
2360
2361 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2362 switch (ctxt->mode) {
2363 case X86EMUL_MODE_PROT32:
2364 if ((msr_data & 0xfffc) == 0x0)
2365 return emulate_gp(ctxt, 0);
2366 break;
2367 case X86EMUL_MODE_PROT64:
2368 if (msr_data == 0x0)
2369 return emulate_gp(ctxt, 0);
2370 break;
2371 default:
2372 break;
2373 }
2374
2375 ctxt->eflags &= ~(EFLG_VM | EFLG_IF);
2376 cs_sel = (u16)msr_data;
2377 cs_sel &= ~SELECTOR_RPL_MASK;
2378 ss_sel = cs_sel + 8;
2379 ss_sel &= ~SELECTOR_RPL_MASK;
2380 if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) {
2381 cs.d = 0;
2382 cs.l = 1;
2383 }
2384
2385 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2386 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2387
2388 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
2389 ctxt->_eip = msr_data;
2390
2391 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
2392 *reg_write(ctxt, VCPU_REGS_RSP) = msr_data;
2393
2394 return X86EMUL_CONTINUE;
2395 }
2396
2397 static int em_sysexit(struct x86_emulate_ctxt *ctxt)
2398 {
2399 const struct x86_emulate_ops *ops = ctxt->ops;
2400 struct desc_struct cs, ss;
2401 u64 msr_data, rcx, rdx;
2402 int usermode;
2403 u16 cs_sel = 0, ss_sel = 0;
2404
2405 /* inject #GP if in real mode or Virtual 8086 mode */
2406 if (ctxt->mode == X86EMUL_MODE_REAL ||
2407 ctxt->mode == X86EMUL_MODE_VM86)
2408 return emulate_gp(ctxt, 0);
2409
2410 setup_syscalls_segments(ctxt, &cs, &ss);
2411
2412 if ((ctxt->rex_prefix & 0x8) != 0x0)
2413 usermode = X86EMUL_MODE_PROT64;
2414 else
2415 usermode = X86EMUL_MODE_PROT32;
2416
2417 rcx = reg_read(ctxt, VCPU_REGS_RCX);
2418 rdx = reg_read(ctxt, VCPU_REGS_RDX);
2419
2420 cs.dpl = 3;
2421 ss.dpl = 3;
2422 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2423 switch (usermode) {
2424 case X86EMUL_MODE_PROT32:
2425 cs_sel = (u16)(msr_data + 16);
2426 if ((msr_data & 0xfffc) == 0x0)
2427 return emulate_gp(ctxt, 0);
2428 ss_sel = (u16)(msr_data + 24);
2429 rcx = (u32)rcx;
2430 rdx = (u32)rdx;
2431 break;
2432 case X86EMUL_MODE_PROT64:
2433 cs_sel = (u16)(msr_data + 32);
2434 if (msr_data == 0x0)
2435 return emulate_gp(ctxt, 0);
2436 ss_sel = cs_sel + 8;
2437 cs.d = 0;
2438 cs.l = 1;
2439 if (is_noncanonical_address(rcx) ||
2440 is_noncanonical_address(rdx))
2441 return emulate_gp(ctxt, 0);
2442 break;
2443 }
2444 cs_sel |= SELECTOR_RPL_MASK;
2445 ss_sel |= SELECTOR_RPL_MASK;
2446
2447 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2448 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2449
2450 ctxt->_eip = rdx;
2451 *reg_write(ctxt, VCPU_REGS_RSP) = rcx;
2452
2453 return X86EMUL_CONTINUE;
2454 }
2455
2456 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt)
2457 {
2458 int iopl;
2459 if (ctxt->mode == X86EMUL_MODE_REAL)
2460 return false;
2461 if (ctxt->mode == X86EMUL_MODE_VM86)
2462 return true;
2463 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
2464 return ctxt->ops->cpl(ctxt) > iopl;
2465 }
2466
2467 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
2468 u16 port, u16 len)
2469 {
2470 const struct x86_emulate_ops *ops = ctxt->ops;
2471 struct desc_struct tr_seg;
2472 u32 base3;
2473 int r;
2474 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7;
2475 unsigned mask = (1 << len) - 1;
2476 unsigned long base;
2477
2478 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR);
2479 if (!tr_seg.p)
2480 return false;
2481 if (desc_limit_scaled(&tr_seg) < 103)
2482 return false;
2483 base = get_desc_base(&tr_seg);
2484 #ifdef CONFIG_X86_64
2485 base |= ((u64)base3) << 32;
2486 #endif
2487 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL);
2488 if (r != X86EMUL_CONTINUE)
2489 return false;
2490 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
2491 return false;
2492 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL);
2493 if (r != X86EMUL_CONTINUE)
2494 return false;
2495 if ((perm >> bit_idx) & mask)
2496 return false;
2497 return true;
2498 }
2499
2500 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
2501 u16 port, u16 len)
2502 {
2503 if (ctxt->perm_ok)
2504 return true;
2505
2506 if (emulator_bad_iopl(ctxt))
2507 if (!emulator_io_port_access_allowed(ctxt, port, len))
2508 return false;
2509
2510 ctxt->perm_ok = true;
2511
2512 return true;
2513 }
2514
2515 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
2516 struct tss_segment_16 *tss)
2517 {
2518 tss->ip = ctxt->_eip;
2519 tss->flag = ctxt->eflags;
2520 tss->ax = reg_read(ctxt, VCPU_REGS_RAX);
2521 tss->cx = reg_read(ctxt, VCPU_REGS_RCX);
2522 tss->dx = reg_read(ctxt, VCPU_REGS_RDX);
2523 tss->bx = reg_read(ctxt, VCPU_REGS_RBX);
2524 tss->sp = reg_read(ctxt, VCPU_REGS_RSP);
2525 tss->bp = reg_read(ctxt, VCPU_REGS_RBP);
2526 tss->si = reg_read(ctxt, VCPU_REGS_RSI);
2527 tss->di = reg_read(ctxt, VCPU_REGS_RDI);
2528
2529 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2530 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2531 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2532 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2533 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2534 }
2535
2536 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
2537 struct tss_segment_16 *tss)
2538 {
2539 int ret;
2540 u8 cpl;
2541
2542 ctxt->_eip = tss->ip;
2543 ctxt->eflags = tss->flag | 2;
2544 *reg_write(ctxt, VCPU_REGS_RAX) = tss->ax;
2545 *reg_write(ctxt, VCPU_REGS_RCX) = tss->cx;
2546 *reg_write(ctxt, VCPU_REGS_RDX) = tss->dx;
2547 *reg_write(ctxt, VCPU_REGS_RBX) = tss->bx;
2548 *reg_write(ctxt, VCPU_REGS_RSP) = tss->sp;
2549 *reg_write(ctxt, VCPU_REGS_RBP) = tss->bp;
2550 *reg_write(ctxt, VCPU_REGS_RSI) = tss->si;
2551 *reg_write(ctxt, VCPU_REGS_RDI) = tss->di;
2552
2553 /*
2554 * SDM says that segment selectors are loaded before segment
2555 * descriptors
2556 */
2557 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR);
2558 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2559 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2560 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2561 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2562
2563 cpl = tss->cs & 3;
2564
2565 /*
2566 * Now load segment descriptors. If fault happens at this stage
2567 * it is handled in a context of new task
2568 */
2569 ret = __load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR, cpl,
2570 true, NULL);
2571 if (ret != X86EMUL_CONTINUE)
2572 return ret;
2573 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl,
2574 true, NULL);
2575 if (ret != X86EMUL_CONTINUE)
2576 return ret;
2577 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl,
2578 true, NULL);
2579 if (ret != X86EMUL_CONTINUE)
2580 return ret;
2581 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl,
2582 true, NULL);
2583 if (ret != X86EMUL_CONTINUE)
2584 return ret;
2585 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl,
2586 true, NULL);
2587 if (ret != X86EMUL_CONTINUE)
2588 return ret;
2589
2590 return X86EMUL_CONTINUE;
2591 }
2592
2593 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
2594 u16 tss_selector, u16 old_tss_sel,
2595 ulong old_tss_base, struct desc_struct *new_desc)
2596 {
2597 const struct x86_emulate_ops *ops = ctxt->ops;
2598 struct tss_segment_16 tss_seg;
2599 int ret;
2600 u32 new_tss_base = get_desc_base(new_desc);
2601
2602 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2603 &ctxt->exception);
2604 if (ret != X86EMUL_CONTINUE)
2605 return ret;
2606
2607 save_state_to_tss16(ctxt, &tss_seg);
2608
2609 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2610 &ctxt->exception);
2611 if (ret != X86EMUL_CONTINUE)
2612 return ret;
2613
2614 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2615 &ctxt->exception);
2616 if (ret != X86EMUL_CONTINUE)
2617 return ret;
2618
2619 if (old_tss_sel != 0xffff) {
2620 tss_seg.prev_task_link = old_tss_sel;
2621
2622 ret = ops->write_std(ctxt, new_tss_base,
2623 &tss_seg.prev_task_link,
2624 sizeof tss_seg.prev_task_link,
2625 &ctxt->exception);
2626 if (ret != X86EMUL_CONTINUE)
2627 return ret;
2628 }
2629
2630 return load_state_from_tss16(ctxt, &tss_seg);
2631 }
2632
2633 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
2634 struct tss_segment_32 *tss)
2635 {
2636 /* CR3 and ldt selector are not saved intentionally */
2637 tss->eip = ctxt->_eip;
2638 tss->eflags = ctxt->eflags;
2639 tss->eax = reg_read(ctxt, VCPU_REGS_RAX);
2640 tss->ecx = reg_read(ctxt, VCPU_REGS_RCX);
2641 tss->edx = reg_read(ctxt, VCPU_REGS_RDX);
2642 tss->ebx = reg_read(ctxt, VCPU_REGS_RBX);
2643 tss->esp = reg_read(ctxt, VCPU_REGS_RSP);
2644 tss->ebp = reg_read(ctxt, VCPU_REGS_RBP);
2645 tss->esi = reg_read(ctxt, VCPU_REGS_RSI);
2646 tss->edi = reg_read(ctxt, VCPU_REGS_RDI);
2647
2648 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2649 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2650 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2651 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2652 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS);
2653 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS);
2654 }
2655
2656 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
2657 struct tss_segment_32 *tss)
2658 {
2659 int ret;
2660 u8 cpl;
2661
2662 if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
2663 return emulate_gp(ctxt, 0);
2664 ctxt->_eip = tss->eip;
2665 ctxt->eflags = tss->eflags | 2;
2666
2667 /* General purpose registers */
2668 *reg_write(ctxt, VCPU_REGS_RAX) = tss->eax;
2669 *reg_write(ctxt, VCPU_REGS_RCX) = tss->ecx;
2670 *reg_write(ctxt, VCPU_REGS_RDX) = tss->edx;
2671 *reg_write(ctxt, VCPU_REGS_RBX) = tss->ebx;
2672 *reg_write(ctxt, VCPU_REGS_RSP) = tss->esp;
2673 *reg_write(ctxt, VCPU_REGS_RBP) = tss->ebp;
2674 *reg_write(ctxt, VCPU_REGS_RSI) = tss->esi;
2675 *reg_write(ctxt, VCPU_REGS_RDI) = tss->edi;
2676
2677 /*
2678 * SDM says that segment selectors are loaded before segment
2679 * descriptors. This is important because CPL checks will
2680 * use CS.RPL.
2681 */
2682 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
2683 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2684 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2685 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2686 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2687 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS);
2688 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
2689
2690 /*
2691 * If we're switching between Protected Mode and VM86, we need to make
2692 * sure to update the mode before loading the segment descriptors so
2693 * that the selectors are interpreted correctly.
2694 */
2695 if (ctxt->eflags & X86_EFLAGS_VM) {
2696 ctxt->mode = X86EMUL_MODE_VM86;
2697 cpl = 3;
2698 } else {
2699 ctxt->mode = X86EMUL_MODE_PROT32;
2700 cpl = tss->cs & 3;
2701 }
2702
2703 /*
2704 * Now load segment descriptors. If fault happenes at this stage
2705 * it is handled in a context of new task
2706 */
2707 ret = __load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR,
2708 cpl, true, NULL);
2709 if (ret != X86EMUL_CONTINUE)
2710 return ret;
2711 ret = __load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES, cpl,
2712 true, NULL);
2713 if (ret != X86EMUL_CONTINUE)
2714 return ret;
2715 ret = __load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS, cpl,
2716 true, NULL);
2717 if (ret != X86EMUL_CONTINUE)
2718 return ret;
2719 ret = __load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS, cpl,
2720 true, NULL);
2721 if (ret != X86EMUL_CONTINUE)
2722 return ret;
2723 ret = __load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS, cpl,
2724 true, NULL);
2725 if (ret != X86EMUL_CONTINUE)
2726 return ret;
2727 ret = __load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS, cpl,
2728 true, NULL);
2729 if (ret != X86EMUL_CONTINUE)
2730 return ret;
2731 ret = __load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS, cpl,
2732 true, NULL);
2733 if (ret != X86EMUL_CONTINUE)
2734 return ret;
2735
2736 return X86EMUL_CONTINUE;
2737 }
2738
2739 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
2740 u16 tss_selector, u16 old_tss_sel,
2741 ulong old_tss_base, struct desc_struct *new_desc)
2742 {
2743 const struct x86_emulate_ops *ops = ctxt->ops;
2744 struct tss_segment_32 tss_seg;
2745 int ret;
2746 u32 new_tss_base = get_desc_base(new_desc);
2747 u32 eip_offset = offsetof(struct tss_segment_32, eip);
2748 u32 ldt_sel_offset = offsetof(struct tss_segment_32, ldt_selector);
2749
2750 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2751 &ctxt->exception);
2752 if (ret != X86EMUL_CONTINUE)
2753 /* FIXME: need to provide precise fault address */
2754 return ret;
2755
2756 save_state_to_tss32(ctxt, &tss_seg);
2757
2758 /* Only GP registers and segment selectors are saved */
2759 ret = ops->write_std(ctxt, old_tss_base + eip_offset, &tss_seg.eip,
2760 ldt_sel_offset - eip_offset, &ctxt->exception);
2761 if (ret != X86EMUL_CONTINUE)
2762 /* FIXME: need to provide precise fault address */
2763 return ret;
2764
2765 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2766 &ctxt->exception);
2767 if (ret != X86EMUL_CONTINUE)
2768 /* FIXME: need to provide precise fault address */
2769 return ret;
2770
2771 if (old_tss_sel != 0xffff) {
2772 tss_seg.prev_task_link = old_tss_sel;
2773
2774 ret = ops->write_std(ctxt, new_tss_base,
2775 &tss_seg.prev_task_link,
2776 sizeof tss_seg.prev_task_link,
2777 &ctxt->exception);
2778 if (ret != X86EMUL_CONTINUE)
2779 /* FIXME: need to provide precise fault address */
2780 return ret;
2781 }
2782
2783 return load_state_from_tss32(ctxt, &tss_seg);
2784 }
2785
2786 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
2787 u16 tss_selector, int idt_index, int reason,
2788 bool has_error_code, u32 error_code)
2789 {
2790 const struct x86_emulate_ops *ops = ctxt->ops;
2791 struct desc_struct curr_tss_desc, next_tss_desc;
2792 int ret;
2793 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR);
2794 ulong old_tss_base =
2795 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR);
2796 u32 desc_limit;
2797 ulong desc_addr;
2798
2799 /* FIXME: old_tss_base == ~0 ? */
2800
2801 ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc, &desc_addr);
2802 if (ret != X86EMUL_CONTINUE)
2803 return ret;
2804 ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc, &desc_addr);
2805 if (ret != X86EMUL_CONTINUE)
2806 return ret;
2807
2808 /* FIXME: check that next_tss_desc is tss */
2809
2810 /*
2811 * Check privileges. The three cases are task switch caused by...
2812 *
2813 * 1. jmp/call/int to task gate: Check against DPL of the task gate
2814 * 2. Exception/IRQ/iret: No check is performed
2815 * 3. jmp/call to TSS/task-gate: No check is performed since the
2816 * hardware checks it before exiting.
2817 */
2818 if (reason == TASK_SWITCH_GATE) {
2819 if (idt_index != -1) {
2820 /* Software interrupts */
2821 struct desc_struct task_gate_desc;
2822 int dpl;
2823
2824 ret = read_interrupt_descriptor(ctxt, idt_index,
2825 &task_gate_desc);
2826 if (ret != X86EMUL_CONTINUE)
2827 return ret;
2828
2829 dpl = task_gate_desc.dpl;
2830 if ((tss_selector & 3) > dpl || ops->cpl(ctxt) > dpl)
2831 return emulate_gp(ctxt, (idt_index << 3) | 0x2);
2832 }
2833 }
2834
2835 desc_limit = desc_limit_scaled(&next_tss_desc);
2836 if (!next_tss_desc.p ||
2837 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
2838 desc_limit < 0x2b)) {
2839 return emulate_ts(ctxt, tss_selector & 0xfffc);
2840 }
2841
2842 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
2843 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
2844 write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
2845 }
2846
2847 if (reason == TASK_SWITCH_IRET)
2848 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
2849
2850 /* set back link to prev task only if NT bit is set in eflags
2851 note that old_tss_sel is not used after this point */
2852 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
2853 old_tss_sel = 0xffff;
2854
2855 if (next_tss_desc.type & 8)
2856 ret = task_switch_32(ctxt, tss_selector, old_tss_sel,
2857 old_tss_base, &next_tss_desc);
2858 else
2859 ret = task_switch_16(ctxt, tss_selector, old_tss_sel,
2860 old_tss_base, &next_tss_desc);
2861 if (ret != X86EMUL_CONTINUE)
2862 return ret;
2863
2864 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
2865 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
2866
2867 if (reason != TASK_SWITCH_IRET) {
2868 next_tss_desc.type |= (1 << 1); /* set busy flag */
2869 write_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
2870 }
2871
2872 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS);
2873 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR);
2874
2875 if (has_error_code) {
2876 ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
2877 ctxt->lock_prefix = 0;
2878 ctxt->src.val = (unsigned long) error_code;
2879 ret = em_push(ctxt);
2880 }
2881
2882 return ret;
2883 }
2884
2885 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
2886 u16 tss_selector, int idt_index, int reason,
2887 bool has_error_code, u32 error_code)
2888 {
2889 int rc;
2890
2891 invalidate_registers(ctxt);
2892 ctxt->_eip = ctxt->eip;
2893 ctxt->dst.type = OP_NONE;
2894
2895 rc = emulator_do_task_switch(ctxt, tss_selector, idt_index, reason,
2896 has_error_code, error_code);
2897
2898 if (rc == X86EMUL_CONTINUE) {
2899 ctxt->eip = ctxt->_eip;
2900 writeback_registers(ctxt);
2901 }
2902
2903 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
2904 }
2905
2906 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, int reg,
2907 struct operand *op)
2908 {
2909 int df = (ctxt->eflags & EFLG_DF) ? -op->count : op->count;
2910
2911 register_address_increment(ctxt, reg, df * op->bytes);
2912 op->addr.mem.ea = register_address(ctxt, reg);
2913 }
2914
2915 static int em_das(struct x86_emulate_ctxt *ctxt)
2916 {
2917 u8 al, old_al;
2918 bool af, cf, old_cf;
2919
2920 cf = ctxt->eflags & X86_EFLAGS_CF;
2921 al = ctxt->dst.val;
2922
2923 old_al = al;
2924 old_cf = cf;
2925 cf = false;
2926 af = ctxt->eflags & X86_EFLAGS_AF;
2927 if ((al & 0x0f) > 9 || af) {
2928 al -= 6;
2929 cf = old_cf | (al >= 250);
2930 af = true;
2931 } else {
2932 af = false;
2933 }
2934 if (old_al > 0x99 || old_cf) {
2935 al -= 0x60;
2936 cf = true;
2937 }
2938
2939 ctxt->dst.val = al;
2940 /* Set PF, ZF, SF */
2941 ctxt->src.type = OP_IMM;
2942 ctxt->src.val = 0;
2943 ctxt->src.bytes = 1;
2944 fastop(ctxt, em_or);
2945 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);
2946 if (cf)
2947 ctxt->eflags |= X86_EFLAGS_CF;
2948 if (af)
2949 ctxt->eflags |= X86_EFLAGS_AF;
2950 return X86EMUL_CONTINUE;
2951 }
2952
2953 static int em_aam(struct x86_emulate_ctxt *ctxt)
2954 {
2955 u8 al, ah;
2956
2957 if (ctxt->src.val == 0)
2958 return emulate_de(ctxt);
2959
2960 al = ctxt->dst.val & 0xff;
2961 ah = al / ctxt->src.val;
2962 al %= ctxt->src.val;
2963
2964 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al | (ah << 8);
2965
2966 /* Set PF, ZF, SF */
2967 ctxt->src.type = OP_IMM;
2968 ctxt->src.val = 0;
2969 ctxt->src.bytes = 1;
2970 fastop(ctxt, em_or);
2971
2972 return X86EMUL_CONTINUE;
2973 }
2974
2975 static int em_aad(struct x86_emulate_ctxt *ctxt)
2976 {
2977 u8 al = ctxt->dst.val & 0xff;
2978 u8 ah = (ctxt->dst.val >> 8) & 0xff;
2979
2980 al = (al + (ah * ctxt->src.val)) & 0xff;
2981
2982 ctxt->dst.val = (ctxt->dst.val & 0xffff0000) | al;
2983
2984 /* Set PF, ZF, SF */
2985 ctxt->src.type = OP_IMM;
2986 ctxt->src.val = 0;
2987 ctxt->src.bytes = 1;
2988 fastop(ctxt, em_or);
2989
2990 return X86EMUL_CONTINUE;
2991 }
2992
2993 static int em_call(struct x86_emulate_ctxt *ctxt)
2994 {
2995 int rc;
2996 long rel = ctxt->src.val;
2997
2998 ctxt->src.val = (unsigned long)ctxt->_eip;
2999 rc = jmp_rel(ctxt, rel);
3000 if (rc != X86EMUL_CONTINUE)
3001 return rc;
3002 return em_push(ctxt);
3003 }
3004
3005 static int em_call_far(struct x86_emulate_ctxt *ctxt)
3006 {
3007 u16 sel, old_cs;
3008 ulong old_eip;
3009 int rc;
3010 struct desc_struct old_desc, new_desc;
3011 const struct x86_emulate_ops *ops = ctxt->ops;
3012 int cpl = ctxt->ops->cpl(ctxt);
3013
3014 old_eip = ctxt->_eip;
3015 ops->get_segment(ctxt, &old_cs, &old_desc, NULL, VCPU_SREG_CS);
3016
3017 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
3018 rc = __load_segment_descriptor(ctxt, sel, VCPU_SREG_CS, cpl, false,
3019 &new_desc);
3020 if (rc != X86EMUL_CONTINUE)
3021 return X86EMUL_CONTINUE;
3022
3023 rc = assign_eip_far(ctxt, ctxt->src.val, &new_desc);
3024 if (rc != X86EMUL_CONTINUE)
3025 goto fail;
3026
3027 ctxt->src.val = old_cs;
3028 rc = em_push(ctxt);
3029 if (rc != X86EMUL_CONTINUE)
3030 goto fail;
3031
3032 ctxt->src.val = old_eip;
3033 rc = em_push(ctxt);
3034 /* If we failed, we tainted the memory, but the very least we should
3035 restore cs */
3036 if (rc != X86EMUL_CONTINUE)
3037 goto fail;
3038 return rc;
3039 fail:
3040 ops->set_segment(ctxt, old_cs, &old_desc, 0, VCPU_SREG_CS);
3041 return rc;
3042
3043 }
3044
3045 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
3046 {
3047 int rc;
3048 unsigned long eip;
3049
3050 rc = emulate_pop(ctxt, &eip, ctxt->op_bytes);
3051 if (rc != X86EMUL_CONTINUE)
3052 return rc;
3053 rc = assign_eip_near(ctxt, eip);
3054 if (rc != X86EMUL_CONTINUE)
3055 return rc;
3056 rsp_increment(ctxt, ctxt->src.val);
3057 return X86EMUL_CONTINUE;
3058 }
3059
3060 static int em_xchg(struct x86_emulate_ctxt *ctxt)
3061 {
3062 /* Write back the register source. */
3063 ctxt->src.val = ctxt->dst.val;
3064 write_register_operand(&ctxt->src);
3065
3066 /* Write back the memory destination with implicit LOCK prefix. */
3067 ctxt->dst.val = ctxt->src.orig_val;
3068 ctxt->lock_prefix = 1;
3069 return X86EMUL_CONTINUE;
3070 }
3071
3072 static int em_imul_3op(struct x86_emulate_ctxt *ctxt)
3073 {
3074 ctxt->dst.val = ctxt->src2.val;
3075 return fastop(ctxt, em_imul);
3076 }
3077
3078 static int em_cwd(struct x86_emulate_ctxt *ctxt)
3079 {
3080 ctxt->dst.type = OP_REG;
3081 ctxt->dst.bytes = ctxt->src.bytes;
3082 ctxt->dst.addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
3083 ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1);
3084
3085 return X86EMUL_CONTINUE;
3086 }
3087
3088 static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
3089 {
3090 u64 tsc = 0;
3091
3092 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc);
3093 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)tsc;
3094 *reg_write(ctxt, VCPU_REGS_RDX) = tsc >> 32;
3095 return X86EMUL_CONTINUE;
3096 }
3097
3098 static int em_rdpmc(struct x86_emulate_ctxt *ctxt)
3099 {
3100 u64 pmc;
3101
3102 if (ctxt->ops->read_pmc(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &pmc))
3103 return emulate_gp(ctxt, 0);
3104 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)pmc;
3105 *reg_write(ctxt, VCPU_REGS_RDX) = pmc >> 32;
3106 return X86EMUL_CONTINUE;
3107 }
3108
3109 static int em_mov(struct x86_emulate_ctxt *ctxt)
3110 {
3111 memcpy(ctxt->dst.valptr, ctxt->src.valptr, sizeof(ctxt->src.valptr));
3112 return X86EMUL_CONTINUE;
3113 }
3114
3115 #define FFL(x) bit(X86_FEATURE_##x)
3116
3117 static int em_movbe(struct x86_emulate_ctxt *ctxt)
3118 {
3119 u32 ebx, ecx, edx, eax = 1;
3120 u16 tmp;
3121
3122 /*
3123 * Check MOVBE is set in the guest-visible CPUID leaf.
3124 */
3125 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
3126 if (!(ecx & FFL(MOVBE)))
3127 return emulate_ud(ctxt);
3128
3129 switch (ctxt->op_bytes) {
3130 case 2:
3131 /*
3132 * From MOVBE definition: "...When the operand size is 16 bits,
3133 * the upper word of the destination register remains unchanged
3134 * ..."
3135 *
3136 * Both casting ->valptr and ->val to u16 breaks strict aliasing
3137 * rules so we have to do the operation almost per hand.
3138 */
3139 tmp = (u16)ctxt->src.val;
3140 ctxt->dst.val &= ~0xffffUL;
3141 ctxt->dst.val |= (unsigned long)swab16(tmp);
3142 break;
3143 case 4:
3144 ctxt->dst.val = swab32((u32)ctxt->src.val);
3145 break;
3146 case 8:
3147 ctxt->dst.val = swab64(ctxt->src.val);
3148 break;
3149 default:
3150 BUG();
3151 }
3152 return X86EMUL_CONTINUE;
3153 }
3154
3155 static int em_cr_write(struct x86_emulate_ctxt *ctxt)
3156 {
3157 if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val))
3158 return emulate_gp(ctxt, 0);
3159
3160 /* Disable writeback. */
3161 ctxt->dst.type = OP_NONE;
3162 return X86EMUL_CONTINUE;
3163 }
3164
3165 static int em_dr_write(struct x86_emulate_ctxt *ctxt)
3166 {
3167 unsigned long val;
3168
3169 if (ctxt->mode == X86EMUL_MODE_PROT64)
3170 val = ctxt->src.val & ~0ULL;
3171 else
3172 val = ctxt->src.val & ~0U;
3173
3174 /* #UD condition is already handled. */
3175 if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0)
3176 return emulate_gp(ctxt, 0);
3177
3178 /* Disable writeback. */
3179 ctxt->dst.type = OP_NONE;
3180 return X86EMUL_CONTINUE;
3181 }
3182
3183 static int em_wrmsr(struct x86_emulate_ctxt *ctxt)
3184 {
3185 u64 msr_data;
3186
3187 msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX)
3188 | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32);
3189 if (ctxt->ops->set_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), msr_data))
3190 return emulate_gp(ctxt, 0);
3191
3192 return X86EMUL_CONTINUE;
3193 }
3194
3195 static int em_rdmsr(struct x86_emulate_ctxt *ctxt)
3196 {
3197 u64 msr_data;
3198
3199 if (ctxt->ops->get_msr(ctxt, reg_read(ctxt, VCPU_REGS_RCX), &msr_data))
3200 return emulate_gp(ctxt, 0);
3201
3202 *reg_write(ctxt, VCPU_REGS_RAX) = (u32)msr_data;
3203 *reg_write(ctxt, VCPU_REGS_RDX) = msr_data >> 32;
3204 return X86EMUL_CONTINUE;
3205 }
3206
3207 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
3208 {
3209 if (ctxt->modrm_reg > VCPU_SREG_GS)
3210 return emulate_ud(ctxt);
3211
3212 ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);
3213 if (ctxt->dst.bytes == 4 && ctxt->dst.type == OP_MEM)
3214 ctxt->dst.bytes = 2;
3215 return X86EMUL_CONTINUE;
3216 }
3217
3218 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
3219 {
3220 u16 sel = ctxt->src.val;
3221
3222 if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS)
3223 return emulate_ud(ctxt);
3224
3225 if (ctxt->modrm_reg == VCPU_SREG_SS)
3226 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
3227
3228 /* Disable writeback. */
3229 ctxt->dst.type = OP_NONE;
3230 return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);
3231 }
3232
3233 static int em_lldt(struct x86_emulate_ctxt *ctxt)
3234 {
3235 u16 sel = ctxt->src.val;
3236
3237 /* Disable writeback. */
3238 ctxt->dst.type = OP_NONE;
3239 return load_segment_descriptor(ctxt, sel, VCPU_SREG_LDTR);
3240 }
3241
3242 static int em_ltr(struct x86_emulate_ctxt *ctxt)
3243 {
3244 u16 sel = ctxt->src.val;
3245
3246 /* Disable writeback. */
3247 ctxt->dst.type = OP_NONE;
3248 return load_segment_descriptor(ctxt, sel, VCPU_SREG_TR);
3249 }
3250
3251 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
3252 {
3253 int rc;
3254 ulong linear;
3255
3256 rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear);
3257 if (rc == X86EMUL_CONTINUE)
3258 ctxt->ops->invlpg(ctxt, linear);
3259 /* Disable writeback. */
3260 ctxt->dst.type = OP_NONE;
3261 return X86EMUL_CONTINUE;
3262 }
3263
3264 static int em_clts(struct x86_emulate_ctxt *ctxt)
3265 {
3266 ulong cr0;
3267
3268 cr0 = ctxt->ops->get_cr(ctxt, 0);
3269 cr0 &= ~X86_CR0_TS;
3270 ctxt->ops->set_cr(ctxt, 0, cr0);
3271 return X86EMUL_CONTINUE;
3272 }
3273
3274 static int em_vmcall(struct x86_emulate_ctxt *ctxt)
3275 {
3276 int rc = ctxt->ops->fix_hypercall(ctxt);
3277
3278 if (rc != X86EMUL_CONTINUE)
3279 return rc;
3280
3281 /* Let the processor re-execute the fixed hypercall */
3282 ctxt->_eip = ctxt->eip;
3283 /* Disable writeback. */
3284 ctxt->dst.type = OP_NONE;
3285 return X86EMUL_CONTINUE;
3286 }
3287
3288 static int emulate_store_desc_ptr(struct x86_emulate_ctxt *ctxt,
3289 void (*get)(struct x86_emulate_ctxt *ctxt,
3290 struct desc_ptr *ptr))
3291 {
3292 struct desc_ptr desc_ptr;
3293
3294 if (ctxt->mode == X86EMUL_MODE_PROT64)
3295 ctxt->op_bytes = 8;
3296 get(ctxt, &desc_ptr);
3297 if (ctxt->op_bytes == 2) {
3298 ctxt->op_bytes = 4;
3299 desc_ptr.address &= 0x00ffffff;
3300 }
3301 /* Disable writeback. */
3302 ctxt->dst.type = OP_NONE;
3303 return segmented_write(ctxt, ctxt->dst.addr.mem,
3304 &desc_ptr, 2 + ctxt->op_bytes);
3305 }
3306
3307 static int em_sgdt(struct x86_emulate_ctxt *ctxt)
3308 {
3309 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_gdt);
3310 }
3311
3312 static int em_sidt(struct x86_emulate_ctxt *ctxt)
3313 {
3314 return emulate_store_desc_ptr(ctxt, ctxt->ops->get_idt);
3315 }
3316
3317 static int em_lgdt_lidt(struct x86_emulate_ctxt *ctxt, bool lgdt)
3318 {
3319 struct desc_ptr desc_ptr;
3320 int rc;
3321
3322 if (ctxt->mode == X86EMUL_MODE_PROT64)
3323 ctxt->op_bytes = 8;
3324 rc = read_descriptor(ctxt, ctxt->src.addr.mem,
3325 &desc_ptr.size, &desc_ptr.address,
3326 ctxt->op_bytes);
3327 if (rc != X86EMUL_CONTINUE)
3328 return rc;
3329 if (ctxt->mode == X86EMUL_MODE_PROT64 &&
3330 is_noncanonical_address(desc_ptr.address))
3331 return emulate_gp(ctxt, 0);
3332 if (lgdt)
3333 ctxt->ops->set_gdt(ctxt, &desc_ptr);
3334 else
3335 ctxt->ops->set_idt(ctxt, &desc_ptr);
3336 /* Disable writeback. */
3337 ctxt->dst.type = OP_NONE;
3338 return X86EMUL_CONTINUE;
3339 }
3340
3341 static int em_lgdt(struct x86_emulate_ctxt *ctxt)
3342 {
3343 return em_lgdt_lidt(ctxt, true);
3344 }
3345
3346 static int em_vmmcall(struct x86_emulate_ctxt *ctxt)
3347 {
3348 int rc;
3349
3350 rc = ctxt->ops->fix_hypercall(ctxt);
3351
3352 /* Disable writeback. */
3353 ctxt->dst.type = OP_NONE;
3354 return rc;
3355 }
3356
3357 static int em_lidt(struct x86_emulate_ctxt *ctxt)
3358 {
3359 return em_lgdt_lidt(ctxt, false);
3360 }
3361
3362 static int em_smsw(struct x86_emulate_ctxt *ctxt)
3363 {
3364 if (ctxt->dst.type == OP_MEM)
3365 ctxt->dst.bytes = 2;
3366 ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0);
3367 return X86EMUL_CONTINUE;
3368 }
3369
3370 static int em_lmsw(struct x86_emulate_ctxt *ctxt)
3371 {
3372 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul)
3373 | (ctxt->src.val & 0x0f));
3374 ctxt->dst.type = OP_NONE;
3375 return X86EMUL_CONTINUE;
3376 }
3377
3378 static int em_loop(struct x86_emulate_ctxt *ctxt)
3379 {
3380 int rc = X86EMUL_CONTINUE;
3381
3382 register_address_increment(ctxt, VCPU_REGS_RCX, -1);
3383 if ((address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) != 0) &&
3384 (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags)))
3385 rc = jmp_rel(ctxt, ctxt->src.val);
3386
3387 return rc;
3388 }
3389
3390 static int em_jcxz(struct x86_emulate_ctxt *ctxt)
3391 {
3392 int rc = X86EMUL_CONTINUE;
3393
3394 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0)
3395 rc = jmp_rel(ctxt, ctxt->src.val);
3396
3397 return rc;
3398 }
3399
3400 static int em_in(struct x86_emulate_ctxt *ctxt)
3401 {
3402 if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val,
3403 &ctxt->dst.val))
3404 return X86EMUL_IO_NEEDED;
3405
3406 return X86EMUL_CONTINUE;
3407 }
3408
3409 static int em_out(struct x86_emulate_ctxt *ctxt)
3410 {
3411 ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val,
3412 &ctxt->src.val, 1);
3413 /* Disable writeback. */
3414 ctxt->dst.type = OP_NONE;
3415 return X86EMUL_CONTINUE;
3416 }
3417
3418 static int em_cli(struct x86_emulate_ctxt *ctxt)
3419 {
3420 if (emulator_bad_iopl(ctxt))
3421 return emulate_gp(ctxt, 0);
3422
3423 ctxt->eflags &= ~X86_EFLAGS_IF;
3424 return X86EMUL_CONTINUE;
3425 }
3426
3427 static int em_sti(struct x86_emulate_ctxt *ctxt)
3428 {
3429 if (emulator_bad_iopl(ctxt))
3430 return emulate_gp(ctxt, 0);
3431
3432 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
3433 ctxt->eflags |= X86_EFLAGS_IF;
3434 return X86EMUL_CONTINUE;
3435 }
3436
3437 static int em_cpuid(struct x86_emulate_ctxt *ctxt)
3438 {
3439 u32 eax, ebx, ecx, edx;
3440
3441 eax = reg_read(ctxt, VCPU_REGS_RAX);
3442 ecx = reg_read(ctxt, VCPU_REGS_RCX);
3443 ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
3444 *reg_write(ctxt, VCPU_REGS_RAX) = eax;
3445 *reg_write(ctxt, VCPU_REGS_RBX) = ebx;
3446 *reg_write(ctxt, VCPU_REGS_RCX) = ecx;
3447 *reg_write(ctxt, VCPU_REGS_RDX) = edx;
3448 return X86EMUL_CONTINUE;
3449 }
3450
3451 static int em_sahf(struct x86_emulate_ctxt *ctxt)
3452 {
3453 u32 flags;
3454
3455 flags = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF;
3456 flags &= *reg_rmw(ctxt, VCPU_REGS_RAX) >> 8;
3457
3458 ctxt->eflags &= ~0xffUL;
3459 ctxt->eflags |= flags | X86_EFLAGS_FIXED;
3460 return X86EMUL_CONTINUE;
3461 }
3462
3463 static int em_lahf(struct x86_emulate_ctxt *ctxt)
3464 {
3465 *reg_rmw(ctxt, VCPU_REGS_RAX) &= ~0xff00UL;
3466 *reg_rmw(ctxt, VCPU_REGS_RAX) |= (ctxt->eflags & 0xff) << 8;
3467 return X86EMUL_CONTINUE;
3468 }
3469
3470 static int em_bswap(struct x86_emulate_ctxt *ctxt)
3471 {
3472 switch (ctxt->op_bytes) {
3473 #ifdef CONFIG_X86_64
3474 case 8:
3475 asm("bswap %0" : "+r"(ctxt->dst.val));
3476 break;
3477 #endif
3478 default:
3479 asm("bswap %0" : "+r"(*(u32 *)&ctxt->dst.val));
3480 break;
3481 }
3482 return X86EMUL_CONTINUE;
3483 }
3484
3485 static int em_clflush(struct x86_emulate_ctxt *ctxt)
3486 {
3487 /* emulating clflush regardless of cpuid */
3488 return X86EMUL_CONTINUE;
3489 }
3490
3491 static bool valid_cr(int nr)
3492 {
3493 switch (nr) {
3494 case 0:
3495 case 2 ... 4:
3496 case 8:
3497 return true;
3498 default:
3499 return false;
3500 }
3501 }
3502
3503 static int check_cr_read(struct x86_emulate_ctxt *ctxt)
3504 {
3505 if (!valid_cr(ctxt->modrm_reg))
3506 return emulate_ud(ctxt);
3507
3508 return X86EMUL_CONTINUE;
3509 }
3510
3511 static int check_cr_write(struct x86_emulate_ctxt *ctxt)
3512 {
3513 u64 new_val = ctxt->src.val64;
3514 int cr = ctxt->modrm_reg;
3515 u64 efer = 0;
3516
3517 static u64 cr_reserved_bits[] = {
3518 0xffffffff00000000ULL,
3519 0, 0, 0, /* CR3 checked later */
3520 CR4_RESERVED_BITS,
3521 0, 0, 0,
3522 CR8_RESERVED_BITS,
3523 };
3524
3525 if (!valid_cr(cr))
3526 return emulate_ud(ctxt);
3527
3528 if (new_val & cr_reserved_bits[cr])
3529 return emulate_gp(ctxt, 0);
3530
3531 switch (cr) {
3532 case 0: {
3533 u64 cr4;
3534 if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) ||
3535 ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD)))
3536 return emulate_gp(ctxt, 0);
3537
3538 cr4 = ctxt->ops->get_cr(ctxt, 4);
3539 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3540
3541 if ((new_val & X86_CR0_PG) && (efer & EFER_LME) &&
3542 !(cr4 & X86_CR4_PAE))
3543 return emulate_gp(ctxt, 0);
3544
3545 break;
3546 }
3547 case 3: {
3548 u64 rsvd = 0;
3549
3550 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3551 if (efer & EFER_LMA)
3552 rsvd = CR3_L_MODE_RESERVED_BITS & ~CR3_PCID_INVD;
3553
3554 if (new_val & rsvd)
3555 return emulate_gp(ctxt, 0);
3556
3557 break;
3558 }
3559 case 4: {
3560 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3561
3562 if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE))
3563 return emulate_gp(ctxt, 0);
3564
3565 break;
3566 }
3567 }
3568
3569 return X86EMUL_CONTINUE;
3570 }
3571
3572 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt)
3573 {
3574 unsigned long dr7;
3575
3576 ctxt->ops->get_dr(ctxt, 7, &dr7);
3577
3578 /* Check if DR7.Global_Enable is set */
3579 return dr7 & (1 << 13);
3580 }
3581
3582 static int check_dr_read(struct x86_emulate_ctxt *ctxt)
3583 {
3584 int dr = ctxt->modrm_reg;
3585 u64 cr4;
3586
3587 if (dr > 7)
3588 return emulate_ud(ctxt);
3589
3590 cr4 = ctxt->ops->get_cr(ctxt, 4);
3591 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
3592 return emulate_ud(ctxt);
3593
3594 if (check_dr7_gd(ctxt)) {
3595 ulong dr6;
3596
3597 ctxt->ops->get_dr(ctxt, 6, &dr6);
3598 dr6 &= ~15;
3599 dr6 |= DR6_BD | DR6_RTM;
3600 ctxt->ops->set_dr(ctxt, 6, dr6);
3601 return emulate_db(ctxt);
3602 }
3603
3604 return X86EMUL_CONTINUE;
3605 }
3606
3607 static int check_dr_write(struct x86_emulate_ctxt *ctxt)
3608 {
3609 u64 new_val = ctxt->src.val64;
3610 int dr = ctxt->modrm_reg;
3611
3612 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL))
3613 return emulate_gp(ctxt, 0);
3614
3615 return check_dr_read(ctxt);
3616 }
3617
3618 static int check_svme(struct x86_emulate_ctxt *ctxt)
3619 {
3620 u64 efer;
3621
3622 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3623
3624 if (!(efer & EFER_SVME))
3625 return emulate_ud(ctxt);
3626
3627 return X86EMUL_CONTINUE;
3628 }
3629
3630 static int check_svme_pa(struct x86_emulate_ctxt *ctxt)
3631 {
3632 u64 rax = reg_read(ctxt, VCPU_REGS_RAX);
3633
3634 /* Valid physical address? */
3635 if (rax & 0xffff000000000000ULL)
3636 return emulate_gp(ctxt, 0);
3637
3638 return check_svme(ctxt);
3639 }
3640
3641 static int check_rdtsc(struct x86_emulate_ctxt *ctxt)
3642 {
3643 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3644
3645 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt))
3646 return emulate_ud(ctxt);
3647
3648 return X86EMUL_CONTINUE;
3649 }
3650
3651 static int check_rdpmc(struct x86_emulate_ctxt *ctxt)
3652 {
3653 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3654 u64 rcx = reg_read(ctxt, VCPU_REGS_RCX);
3655
3656 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) ||
3657 ctxt->ops->check_pmc(ctxt, rcx))
3658 return emulate_gp(ctxt, 0);
3659
3660 return X86EMUL_CONTINUE;
3661 }
3662
3663 static int check_perm_in(struct x86_emulate_ctxt *ctxt)
3664 {
3665 ctxt->dst.bytes = min(ctxt->dst.bytes, 4u);
3666 if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes))
3667 return emulate_gp(ctxt, 0);
3668
3669 return X86EMUL_CONTINUE;
3670 }
3671
3672 static int check_perm_out(struct x86_emulate_ctxt *ctxt)
3673 {
3674 ctxt->src.bytes = min(ctxt->src.bytes, 4u);
3675 if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes))
3676 return emulate_gp(ctxt, 0);
3677
3678 return X86EMUL_CONTINUE;
3679 }
3680
3681 #define D(_y) { .flags = (_y) }
3682 #define DI(_y, _i) { .flags = (_y)|Intercept, .intercept = x86_intercept_##_i }
3683 #define DIP(_y, _i, _p) { .flags = (_y)|Intercept|CheckPerm, \
3684 .intercept = x86_intercept_##_i, .check_perm = (_p) }
3685 #define N D(NotImpl)
3686 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) }
3687 #define G(_f, _g) { .flags = ((_f) | Group | ModRM), .u.group = (_g) }
3688 #define GD(_f, _g) { .flags = ((_f) | GroupDual | ModRM), .u.gdual = (_g) }
3689 #define ID(_f, _i) { .flags = ((_f) | InstrDual | ModRM), .u.idual = (_i) }
3690 #define E(_f, _e) { .flags = ((_f) | Escape | ModRM), .u.esc = (_e) }
3691 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
3692 #define F(_f, _e) { .flags = (_f) | Fastop, .u.fastop = (_e) }
3693 #define II(_f, _e, _i) \
3694 { .flags = (_f)|Intercept, .u.execute = (_e), .intercept = x86_intercept_##_i }
3695 #define IIP(_f, _e, _i, _p) \
3696 { .flags = (_f)|Intercept|CheckPerm, .u.execute = (_e), \
3697 .intercept = x86_intercept_##_i, .check_perm = (_p) }
3698 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }
3699
3700 #define D2bv(_f) D((_f) | ByteOp), D(_f)
3701 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p)
3702 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e)
3703 #define F2bv(_f, _e) F((_f) | ByteOp, _e), F(_f, _e)
3704 #define I2bvIP(_f, _e, _i, _p) \
3705 IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p)
3706
3707 #define F6ALU(_f, _e) F2bv((_f) | DstMem | SrcReg | ModRM, _e), \
3708 F2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \
3709 F2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)
3710
3711 static const struct opcode group7_rm0[] = {
3712 N,
3713 I(SrcNone | Priv | EmulateOnUD, em_vmcall),
3714 N, N, N, N, N, N,
3715 };
3716
3717 static const struct opcode group7_rm1[] = {
3718 DI(SrcNone | Priv, monitor),
3719 DI(SrcNone | Priv, mwait),
3720 N, N, N, N, N, N,
3721 };
3722
3723 static const struct opcode group7_rm3[] = {
3724 DIP(SrcNone | Prot | Priv, vmrun, check_svme_pa),
3725 II(SrcNone | Prot | EmulateOnUD, em_vmmcall, vmmcall),
3726 DIP(SrcNone | Prot | Priv, vmload, check_svme_pa),
3727 DIP(SrcNone | Prot | Priv, vmsave, check_svme_pa),
3728 DIP(SrcNone | Prot | Priv, stgi, check_svme),
3729 DIP(SrcNone | Prot | Priv, clgi, check_svme),
3730 DIP(SrcNone | Prot | Priv, skinit, check_svme),
3731 DIP(SrcNone | Prot | Priv, invlpga, check_svme),
3732 };
3733
3734 static const struct opcode group7_rm7[] = {
3735 N,
3736 DIP(SrcNone, rdtscp, check_rdtsc),
3737 N, N, N, N, N, N,
3738 };
3739
3740 static const struct opcode group1[] = {
3741 F(Lock, em_add),
3742 F(Lock | PageTable, em_or),
3743 F(Lock, em_adc),
3744 F(Lock, em_sbb),
3745 F(Lock | PageTable, em_and),
3746 F(Lock, em_sub),
3747 F(Lock, em_xor),
3748 F(NoWrite, em_cmp),
3749 };
3750
3751 static const struct opcode group1A[] = {
3752 I(DstMem | SrcNone | Mov | Stack, em_pop), N, N, N, N, N, N, N,
3753 };
3754
3755 static const struct opcode group2[] = {
3756 F(DstMem | ModRM, em_rol),
3757 F(DstMem | ModRM, em_ror),
3758 F(DstMem | ModRM, em_rcl),
3759 F(DstMem | ModRM, em_rcr),
3760 F(DstMem | ModRM, em_shl),
3761 F(DstMem | ModRM, em_shr),
3762 F(DstMem | ModRM, em_shl),
3763 F(DstMem | ModRM, em_sar),
3764 };
3765
3766 static const struct opcode group3[] = {
3767 F(DstMem | SrcImm | NoWrite, em_test),
3768 F(DstMem | SrcImm | NoWrite, em_test),
3769 F(DstMem | SrcNone | Lock, em_not),
3770 F(DstMem | SrcNone | Lock, em_neg),
3771 F(DstXacc | Src2Mem, em_mul_ex),
3772 F(DstXacc | Src2Mem, em_imul_ex),
3773 F(DstXacc | Src2Mem, em_div_ex),
3774 F(DstXacc | Src2Mem, em_idiv_ex),
3775 };
3776
3777 static const struct opcode group4[] = {
3778 F(ByteOp | DstMem | SrcNone | Lock, em_inc),
3779 F(ByteOp | DstMem | SrcNone | Lock, em_dec),
3780 N, N, N, N, N, N,
3781 };
3782
3783 static const struct opcode group5[] = {
3784 F(DstMem | SrcNone | Lock, em_inc),
3785 F(DstMem | SrcNone | Lock, em_dec),
3786 I(SrcMem | NearBranch, em_call_near_abs),
3787 I(SrcMemFAddr | ImplicitOps | Stack, em_call_far),
3788 I(SrcMem | NearBranch, em_jmp_abs),
3789 I(SrcMemFAddr | ImplicitOps, em_jmp_far),
3790 I(SrcMem | Stack, em_push), D(Undefined),
3791 };
3792
3793 static const struct opcode group6[] = {
3794 DI(Prot, sldt),
3795 DI(Prot, str),
3796 II(Prot | Priv | SrcMem16, em_lldt, lldt),
3797 II(Prot | Priv | SrcMem16, em_ltr, ltr),
3798 N, N, N, N,
3799 };
3800
3801 static const struct group_dual group7 = { {
3802 II(Mov | DstMem, em_sgdt, sgdt),
3803 II(Mov | DstMem, em_sidt, sidt),
3804 II(SrcMem | Priv, em_lgdt, lgdt),
3805 II(SrcMem | Priv, em_lidt, lidt),
3806 II(SrcNone | DstMem | Mov, em_smsw, smsw), N,
3807 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw),
3808 II(SrcMem | ByteOp | Priv | NoAccess, em_invlpg, invlpg),
3809 }, {
3810 EXT(0, group7_rm0),
3811 EXT(0, group7_rm1),
3812 N, EXT(0, group7_rm3),
3813 II(SrcNone | DstMem | Mov, em_smsw, smsw), N,
3814 II(SrcMem16 | Mov | Priv, em_lmsw, lmsw),
3815 EXT(0, group7_rm7),
3816 } };
3817
3818 static const struct opcode group8[] = {
3819 N, N, N, N,
3820 F(DstMem | SrcImmByte | NoWrite, em_bt),
3821 F(DstMem | SrcImmByte | Lock | PageTable, em_bts),
3822 F(DstMem | SrcImmByte | Lock, em_btr),
3823 F(DstMem | SrcImmByte | Lock | PageTable, em_btc),
3824 };
3825
3826 static const struct group_dual group9 = { {
3827 N, I(DstMem64 | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N,
3828 }, {
3829 N, N, N, N, N, N, N, N,
3830 } };
3831
3832 static const struct opcode group11[] = {
3833 I(DstMem | SrcImm | Mov | PageTable, em_mov),
3834 X7(D(Undefined)),
3835 };
3836
3837 static const struct gprefix pfx_0f_ae_7 = {
3838 I(SrcMem | ByteOp, em_clflush), N, N, N,
3839 };
3840
3841 static const struct group_dual group15 = { {
3842 N, N, N, N, N, N, N, GP(0, &pfx_0f_ae_7),
3843 }, {
3844 N, N, N, N, N, N, N, N,
3845 } };
3846
3847 static const struct gprefix pfx_0f_6f_0f_7f = {
3848 I(Mmx, em_mov), I(Sse | Aligned, em_mov), N, I(Sse | Unaligned, em_mov),
3849 };
3850
3851 static const struct instr_dual instr_dual_0f_2b = {
3852 I(0, em_mov), N
3853 };
3854
3855 static const struct gprefix pfx_0f_2b = {
3856 ID(0, &instr_dual_0f_2b), ID(0, &instr_dual_0f_2b), N, N,
3857 };
3858
3859 static const struct gprefix pfx_0f_28_0f_29 = {
3860 I(Aligned, em_mov), I(Aligned, em_mov), N, N,
3861 };
3862
3863 static const struct gprefix pfx_0f_e7 = {
3864 N, I(Sse, em_mov), N, N,
3865 };
3866
3867 static const struct escape escape_d9 = { {
3868 N, N, N, N, N, N, N, I(DstMem, em_fnstcw),
3869 }, {
3870 /* 0xC0 - 0xC7 */
3871 N, N, N, N, N, N, N, N,
3872 /* 0xC8 - 0xCF */
3873 N, N, N, N, N, N, N, N,
3874 /* 0xD0 - 0xC7 */
3875 N, N, N, N, N, N, N, N,
3876 /* 0xD8 - 0xDF */
3877 N, N, N, N, N, N, N, N,
3878 /* 0xE0 - 0xE7 */
3879 N, N, N, N, N, N, N, N,
3880 /* 0xE8 - 0xEF */
3881 N, N, N, N, N, N, N, N,
3882 /* 0xF0 - 0xF7 */
3883 N, N, N, N, N, N, N, N,
3884 /* 0xF8 - 0xFF */
3885 N, N, N, N, N, N, N, N,
3886 } };
3887
3888 static const struct escape escape_db = { {
3889 N, N, N, N, N, N, N, N,
3890 }, {
3891 /* 0xC0 - 0xC7 */
3892 N, N, N, N, N, N, N, N,
3893 /* 0xC8 - 0xCF */
3894 N, N, N, N, N, N, N, N,
3895 /* 0xD0 - 0xC7 */
3896 N, N, N, N, N, N, N, N,
3897 /* 0xD8 - 0xDF */
3898 N, N, N, N, N, N, N, N,
3899 /* 0xE0 - 0xE7 */
3900 N, N, N, I(ImplicitOps, em_fninit), N, N, N, N,
3901 /* 0xE8 - 0xEF */
3902 N, N, N, N, N, N, N, N,
3903 /* 0xF0 - 0xF7 */
3904 N, N, N, N, N, N, N, N,
3905 /* 0xF8 - 0xFF */
3906 N, N, N, N, N, N, N, N,
3907 } };
3908
3909 static const struct escape escape_dd = { {
3910 N, N, N, N, N, N, N, I(DstMem, em_fnstsw),
3911 }, {
3912 /* 0xC0 - 0xC7 */
3913 N, N, N, N, N, N, N, N,
3914 /* 0xC8 - 0xCF */
3915 N, N, N, N, N, N, N, N,
3916 /* 0xD0 - 0xC7 */
3917 N, N, N, N, N, N, N, N,
3918 /* 0xD8 - 0xDF */
3919 N, N, N, N, N, N, N, N,
3920 /* 0xE0 - 0xE7 */
3921 N, N, N, N, N, N, N, N,
3922 /* 0xE8 - 0xEF */
3923 N, N, N, N, N, N, N, N,
3924 /* 0xF0 - 0xF7 */
3925 N, N, N, N, N, N, N, N,
3926 /* 0xF8 - 0xFF */
3927 N, N, N, N, N, N, N, N,
3928 } };
3929
3930 static const struct instr_dual instr_dual_0f_c3 = {
3931 I(DstMem | SrcReg | ModRM | No16 | Mov, em_mov), N
3932 };
3933
3934 static const struct opcode opcode_table[256] = {
3935 /* 0x00 - 0x07 */
3936 F6ALU(Lock, em_add),
3937 I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg),
3938 I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg),
3939 /* 0x08 - 0x0F */
3940 F6ALU(Lock | PageTable, em_or),
3941 I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg),
3942 N,
3943 /* 0x10 - 0x17 */
3944 F6ALU(Lock, em_adc),
3945 I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg),
3946 I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg),
3947 /* 0x18 - 0x1F */
3948 F6ALU(Lock, em_sbb),
3949 I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg),
3950 I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg),
3951 /* 0x20 - 0x27 */
3952 F6ALU(Lock | PageTable, em_and), N, N,
3953 /* 0x28 - 0x2F */
3954 F6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),
3955 /* 0x30 - 0x37 */
3956 F6ALU(Lock, em_xor), N, N,
3957 /* 0x38 - 0x3F */
3958 F6ALU(NoWrite, em_cmp), N, N,
3959 /* 0x40 - 0x4F */
3960 X8(F(DstReg, em_inc)), X8(F(DstReg, em_dec)),
3961 /* 0x50 - 0x57 */
3962 X8(I(SrcReg | Stack, em_push)),
3963 /* 0x58 - 0x5F */
3964 X8(I(DstReg | Stack, em_pop)),
3965 /* 0x60 - 0x67 */
3966 I(ImplicitOps | Stack | No64, em_pusha),
3967 I(ImplicitOps | Stack | No64, em_popa),
3968 N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ ,
3969 N, N, N, N,
3970 /* 0x68 - 0x6F */
3971 I(SrcImm | Mov | Stack, em_push),
3972 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
3973 I(SrcImmByte | Mov | Stack, em_push),
3974 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
3975 I2bvIP(DstDI | SrcDX | Mov | String | Unaligned, em_in, ins, check_perm_in), /* insb, insw/insd */
3976 I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */
3977 /* 0x70 - 0x7F */
3978 X16(D(SrcImmByte | NearBranch)),
3979 /* 0x80 - 0x87 */
3980 G(ByteOp | DstMem | SrcImm, group1),
3981 G(DstMem | SrcImm, group1),
3982 G(ByteOp | DstMem | SrcImm | No64, group1),
3983 G(DstMem | SrcImmByte, group1),
3984 F2bv(DstMem | SrcReg | ModRM | NoWrite, em_test),
3985 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg),
3986 /* 0x88 - 0x8F */
3987 I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov),
3988 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
3989 I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg),
3990 D(ModRM | SrcMem | NoAccess | DstReg),
3991 I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm),
3992 G(0, group1A),
3993 /* 0x90 - 0x97 */
3994 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)),
3995 /* 0x98 - 0x9F */
3996 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
3997 I(SrcImmFAddr | No64, em_call_far), N,
3998 II(ImplicitOps | Stack, em_pushf, pushf),
3999 II(ImplicitOps | Stack, em_popf, popf),
4000 I(ImplicitOps, em_sahf), I(ImplicitOps, em_lahf),
4001 /* 0xA0 - 0xA7 */
4002 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
4003 I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov),
4004 I2bv(SrcSI | DstDI | Mov | String, em_mov),
4005 F2bv(SrcSI | DstDI | String | NoWrite, em_cmp_r),
4006 /* 0xA8 - 0xAF */
4007 F2bv(DstAcc | SrcImm | NoWrite, em_test),
4008 I2bv(SrcAcc | DstDI | Mov | String, em_mov),
4009 I2bv(SrcSI | DstAcc | Mov | String, em_mov),
4010 F2bv(SrcAcc | DstDI | String | NoWrite, em_cmp_r),
4011 /* 0xB0 - 0xB7 */
4012 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
4013 /* 0xB8 - 0xBF */
4014 X8(I(DstReg | SrcImm64 | Mov, em_mov)),
4015 /* 0xC0 - 0xC7 */
4016 G(ByteOp | Src2ImmByte, group2), G(Src2ImmByte, group2),
4017 I(ImplicitOps | NearBranch | SrcImmU16, em_ret_near_imm),
4018 I(ImplicitOps | NearBranch, em_ret),
4019 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),
4020 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
4021 G(ByteOp, group11), G(0, group11),
4022 /* 0xC8 - 0xCF */
4023 I(Stack | SrcImmU16 | Src2ImmByte, em_enter), I(Stack, em_leave),
4024 I(ImplicitOps | Stack | SrcImmU16, em_ret_far_imm),
4025 I(ImplicitOps | Stack, em_ret_far),
4026 D(ImplicitOps), DI(SrcImmByte, intn),
4027 D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
4028 /* 0xD0 - 0xD7 */
4029 G(Src2One | ByteOp, group2), G(Src2One, group2),
4030 G(Src2CL | ByteOp, group2), G(Src2CL, group2),
4031 I(DstAcc | SrcImmUByte | No64, em_aam),
4032 I(DstAcc | SrcImmUByte | No64, em_aad),
4033 F(DstAcc | ByteOp | No64, em_salc),
4034 I(DstAcc | SrcXLat | ByteOp, em_mov),
4035 /* 0xD8 - 0xDF */
4036 N, E(0, &escape_d9), N, E(0, &escape_db), N, E(0, &escape_dd), N, N,
4037 /* 0xE0 - 0xE7 */
4038 X3(I(SrcImmByte | NearBranch, em_loop)),
4039 I(SrcImmByte | NearBranch, em_jcxz),
4040 I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in),
4041 I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out),
4042 /* 0xE8 - 0xEF */
4043 I(SrcImm | NearBranch, em_call), D(SrcImm | ImplicitOps | NearBranch),
4044 I(SrcImmFAddr | No64, em_jmp_far),
4045 D(SrcImmByte | ImplicitOps | NearBranch),
4046 I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in),
4047 I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out),
4048 /* 0xF0 - 0xF7 */
4049 N, DI(ImplicitOps, icebp), N, N,
4050 DI(ImplicitOps | Priv, hlt), D(ImplicitOps),
4051 G(ByteOp, group3), G(0, group3),
4052 /* 0xF8 - 0xFF */
4053 D(ImplicitOps), D(ImplicitOps),
4054 I(ImplicitOps, em_cli), I(ImplicitOps, em_sti),
4055 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5),
4056 };
4057
4058 static const struct opcode twobyte_table[256] = {
4059 /* 0x00 - 0x0F */
4060 G(0, group6), GD(0, &group7), N, N,
4061 N, I(ImplicitOps | EmulateOnUD, em_syscall),
4062 II(ImplicitOps | Priv, em_clts, clts), N,
4063 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N,
4064 N, D(ImplicitOps | ModRM | SrcMem | NoAccess), N, N,
4065 /* 0x10 - 0x1F */
4066 N, N, N, N, N, N, N, N,
4067 D(ImplicitOps | ModRM | SrcMem | NoAccess),
4068 N, N, N, N, N, N, D(ImplicitOps | ModRM | SrcMem | NoAccess),
4069 /* 0x20 - 0x2F */
4070 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, cr_read, check_cr_read),
4071 DIP(ModRM | DstMem | Priv | Op3264 | NoMod, dr_read, check_dr_read),
4072 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_cr_write, cr_write,
4073 check_cr_write),
4074 IIP(ModRM | SrcMem | Priv | Op3264 | NoMod, em_dr_write, dr_write,
4075 check_dr_write),
4076 N, N, N, N,
4077 GP(ModRM | DstReg | SrcMem | Mov | Sse, &pfx_0f_28_0f_29),
4078 GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_28_0f_29),
4079 N, GP(ModRM | DstMem | SrcReg | Mov | Sse, &pfx_0f_2b),
4080 N, N, N, N,
4081 /* 0x30 - 0x3F */
4082 II(ImplicitOps | Priv, em_wrmsr, wrmsr),
4083 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
4084 II(ImplicitOps | Priv, em_rdmsr, rdmsr),
4085 IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc),
4086 I(ImplicitOps | EmulateOnUD, em_sysenter),
4087 I(ImplicitOps | Priv | EmulateOnUD, em_sysexit),
4088 N, N,
4089 N, N, N, N, N, N, N, N,
4090 /* 0x40 - 0x4F */
4091 X16(D(DstReg | SrcMem | ModRM)),
4092 /* 0x50 - 0x5F */
4093 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
4094 /* 0x60 - 0x6F */
4095 N, N, N, N,
4096 N, N, N, N,
4097 N, N, N, N,
4098 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f),
4099 /* 0x70 - 0x7F */
4100 N, N, N, N,
4101 N, N, N, N,
4102 N, N, N, N,
4103 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),
4104 /* 0x80 - 0x8F */
4105 X16(D(SrcImm | NearBranch)),
4106 /* 0x90 - 0x9F */
4107 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
4108 /* 0xA0 - 0xA7 */
4109 I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
4110 II(ImplicitOps, em_cpuid, cpuid),
4111 F(DstMem | SrcReg | ModRM | BitOp | NoWrite, em_bt),
4112 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shld),
4113 F(DstMem | SrcReg | Src2CL | ModRM, em_shld), N, N,
4114 /* 0xA8 - 0xAF */
4115 I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
4116 DI(ImplicitOps, rsm),
4117 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
4118 F(DstMem | SrcReg | Src2ImmByte | ModRM, em_shrd),
4119 F(DstMem | SrcReg | Src2CL | ModRM, em_shrd),
4120 GD(0, &group15), F(DstReg | SrcMem | ModRM, em_imul),
4121 /* 0xB0 - 0xB7 */
4122 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
4123 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
4124 F(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
4125 I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
4126 I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
4127 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
4128 /* 0xB8 - 0xBF */
4129 N, N,
4130 G(BitOp, group8),
4131 F(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
4132 F(DstReg | SrcMem | ModRM, em_bsf), F(DstReg | SrcMem | ModRM, em_bsr),
4133 D(DstReg | SrcMem8 | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
4134 /* 0xC0 - 0xC7 */
4135 F2bv(DstMem | SrcReg | ModRM | SrcWrite | Lock, em_xadd),
4136 N, ID(0, &instr_dual_0f_c3),
4137 N, N, N, GD(0, &group9),
4138 /* 0xC8 - 0xCF */
4139 X8(I(DstReg, em_bswap)),
4140 /* 0xD0 - 0xDF */
4141 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
4142 /* 0xE0 - 0xEF */
4143 N, N, N, N, N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_e7),
4144 N, N, N, N, N, N, N, N,
4145 /* 0xF0 - 0xFF */
4146 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N
4147 };
4148
4149 static const struct instr_dual instr_dual_0f_38_f0 = {
4150 I(DstReg | SrcMem | Mov, em_movbe), N
4151 };
4152
4153 static const struct instr_dual instr_dual_0f_38_f1 = {
4154 I(DstMem | SrcReg | Mov, em_movbe), N
4155 };
4156
4157 static const struct gprefix three_byte_0f_38_f0 = {
4158 ID(0, &instr_dual_0f_38_f0), N, N, N
4159 };
4160
4161 static const struct gprefix three_byte_0f_38_f1 = {
4162 ID(0, &instr_dual_0f_38_f1), N, N, N
4163 };
4164
4165 /*
4166 * Insns below are selected by the prefix which indexed by the third opcode
4167 * byte.
4168 */
4169 static const struct opcode opcode_map_0f_38[256] = {
4170 /* 0x00 - 0x7f */
4171 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N),
4172 /* 0x80 - 0xef */
4173 X16(N), X16(N), X16(N), X16(N), X16(N), X16(N), X16(N),
4174 /* 0xf0 - 0xf1 */
4175 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f0),
4176 GP(EmulateOnUD | ModRM, &three_byte_0f_38_f1),
4177 /* 0xf2 - 0xff */
4178 N, N, X4(N), X8(N)
4179 };
4180
4181 #undef D
4182 #undef N
4183 #undef G
4184 #undef GD
4185 #undef I
4186 #undef GP
4187 #undef EXT
4188
4189 #undef D2bv
4190 #undef D2bvIP
4191 #undef I2bv
4192 #undef I2bvIP
4193 #undef I6ALU
4194
4195 static unsigned imm_size(struct x86_emulate_ctxt *ctxt)
4196 {
4197 unsigned size;
4198
4199 size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4200 if (size == 8)
4201 size = 4;
4202 return size;
4203 }
4204
4205 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op,
4206 unsigned size, bool sign_extension)
4207 {
4208 int rc = X86EMUL_CONTINUE;
4209
4210 op->type = OP_IMM;
4211 op->bytes = size;
4212 op->addr.mem.ea = ctxt->_eip;
4213 /* NB. Immediates are sign-extended as necessary. */
4214 switch (op->bytes) {
4215 case 1:
4216 op->val = insn_fetch(s8, ctxt);
4217 break;
4218 case 2:
4219 op->val = insn_fetch(s16, ctxt);
4220 break;
4221 case 4:
4222 op->val = insn_fetch(s32, ctxt);
4223 break;
4224 case 8:
4225 op->val = insn_fetch(s64, ctxt);
4226 break;
4227 }
4228 if (!sign_extension) {
4229 switch (op->bytes) {
4230 case 1:
4231 op->val &= 0xff;
4232 break;
4233 case 2:
4234 op->val &= 0xffff;
4235 break;
4236 case 4:
4237 op->val &= 0xffffffff;
4238 break;
4239 }
4240 }
4241 done:
4242 return rc;
4243 }
4244
4245 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
4246 unsigned d)
4247 {
4248 int rc = X86EMUL_CONTINUE;
4249
4250 switch (d) {
4251 case OpReg:
4252 decode_register_operand(ctxt, op);
4253 break;
4254 case OpImmUByte:
4255 rc = decode_imm(ctxt, op, 1, false);
4256 break;
4257 case OpMem:
4258 ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4259 mem_common:
4260 *op = ctxt->memop;
4261 ctxt->memopp = op;
4262 if (ctxt->d & BitOp)
4263 fetch_bit_operand(ctxt);
4264 op->orig_val = op->val;
4265 break;
4266 case OpMem64:
4267 ctxt->memop.bytes = (ctxt->op_bytes == 8) ? 16 : 8;
4268 goto mem_common;
4269 case OpAcc:
4270 op->type = OP_REG;
4271 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4272 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
4273 fetch_register_operand(op);
4274 op->orig_val = op->val;
4275 break;
4276 case OpAccLo:
4277 op->type = OP_REG;
4278 op->bytes = (ctxt->d & ByteOp) ? 2 : ctxt->op_bytes;
4279 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RAX);
4280 fetch_register_operand(op);
4281 op->orig_val = op->val;
4282 break;
4283 case OpAccHi:
4284 if (ctxt->d & ByteOp) {
4285 op->type = OP_NONE;
4286 break;
4287 }
4288 op->type = OP_REG;
4289 op->bytes = ctxt->op_bytes;
4290 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
4291 fetch_register_operand(op);
4292 op->orig_val = op->val;
4293 break;
4294 case OpDI:
4295 op->type = OP_MEM;
4296 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4297 op->addr.mem.ea =
4298 register_address(ctxt, VCPU_REGS_RDI);
4299 op->addr.mem.seg = VCPU_SREG_ES;
4300 op->val = 0;
4301 op->count = 1;
4302 break;
4303 case OpDX:
4304 op->type = OP_REG;
4305 op->bytes = 2;
4306 op->addr.reg = reg_rmw(ctxt, VCPU_REGS_RDX);
4307 fetch_register_operand(op);
4308 break;
4309 case OpCL:
4310 op->bytes = 1;
4311 op->val = reg_read(ctxt, VCPU_REGS_RCX) & 0xff;
4312 break;
4313 case OpImmByte:
4314 rc = decode_imm(ctxt, op, 1, true);
4315 break;
4316 case OpOne:
4317 op->bytes = 1;
4318 op->val = 1;
4319 break;
4320 case OpImm:
4321 rc = decode_imm(ctxt, op, imm_size(ctxt), true);
4322 break;
4323 case OpImm64:
4324 rc = decode_imm(ctxt, op, ctxt->op_bytes, true);
4325 break;
4326 case OpMem8:
4327 ctxt->memop.bytes = 1;
4328 if (ctxt->memop.type == OP_REG) {
4329 ctxt->memop.addr.reg = decode_register(ctxt,
4330 ctxt->modrm_rm, true);
4331 fetch_register_operand(&ctxt->memop);
4332 }
4333 goto mem_common;
4334 case OpMem16:
4335 ctxt->memop.bytes = 2;
4336 goto mem_common;
4337 case OpMem32:
4338 ctxt->memop.bytes = 4;
4339 goto mem_common;
4340 case OpImmU16:
4341 rc = decode_imm(ctxt, op, 2, false);
4342 break;
4343 case OpImmU:
4344 rc = decode_imm(ctxt, op, imm_size(ctxt), false);
4345 break;
4346 case OpSI:
4347 op->type = OP_MEM;
4348 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4349 op->addr.mem.ea =
4350 register_address(ctxt, VCPU_REGS_RSI);
4351 op->addr.mem.seg = ctxt->seg_override;
4352 op->val = 0;
4353 op->count = 1;
4354 break;
4355 case OpXLat:
4356 op->type = OP_MEM;
4357 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
4358 op->addr.mem.ea =
4359 address_mask(ctxt,
4360 reg_read(ctxt, VCPU_REGS_RBX) +
4361 (reg_read(ctxt, VCPU_REGS_RAX) & 0xff));
4362 op->addr.mem.seg = ctxt->seg_override;
4363 op->val = 0;
4364 break;
4365 case OpImmFAddr:
4366 op->type = OP_IMM;
4367 op->addr.mem.ea = ctxt->_eip;
4368 op->bytes = ctxt->op_bytes + 2;
4369 insn_fetch_arr(op->valptr, op->bytes, ctxt);
4370 break;
4371 case OpMemFAddr:
4372 ctxt->memop.bytes = ctxt->op_bytes + 2;
4373 goto mem_common;
4374 case OpES:
4375 op->val = VCPU_SREG_ES;
4376 break;
4377 case OpCS:
4378 op->val = VCPU_SREG_CS;
4379 break;
4380 case OpSS:
4381 op->val = VCPU_SREG_SS;
4382 break;
4383 case OpDS:
4384 op->val = VCPU_SREG_DS;
4385 break;
4386 case OpFS:
4387 op->val = VCPU_SREG_FS;
4388 break;
4389 case OpGS:
4390 op->val = VCPU_SREG_GS;
4391 break;
4392 case OpImplicit:
4393 /* Special instructions do their own operand decoding. */
4394 default:
4395 op->type = OP_NONE; /* Disable writeback. */
4396 break;
4397 }
4398
4399 done:
4400 return rc;
4401 }
4402
4403 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
4404 {
4405 int rc = X86EMUL_CONTINUE;
4406 int mode = ctxt->mode;
4407 int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
4408 bool op_prefix = false;
4409 bool has_seg_override = false;
4410 struct opcode opcode;
4411
4412 ctxt->memop.type = OP_NONE;
4413 ctxt->memopp = NULL;
4414 ctxt->_eip = ctxt->eip;
4415 ctxt->fetch.ptr = ctxt->fetch.data;
4416 ctxt->fetch.end = ctxt->fetch.data + insn_len;
4417 ctxt->opcode_len = 1;
4418 if (insn_len > 0)
4419 memcpy(ctxt->fetch.data, insn, insn_len);
4420 else {
4421 rc = __do_insn_fetch_bytes(ctxt, 1);
4422 if (rc != X86EMUL_CONTINUE)
4423 return rc;
4424 }
4425
4426 switch (mode) {
4427 case X86EMUL_MODE_REAL:
4428 case X86EMUL_MODE_VM86:
4429 case X86EMUL_MODE_PROT16:
4430 def_op_bytes = def_ad_bytes = 2;
4431 break;
4432 case X86EMUL_MODE_PROT32:
4433 def_op_bytes = def_ad_bytes = 4;
4434 break;
4435 #ifdef CONFIG_X86_64
4436 case X86EMUL_MODE_PROT64:
4437 def_op_bytes = 4;
4438 def_ad_bytes = 8;
4439 break;
4440 #endif
4441 default:
4442 return EMULATION_FAILED;
4443 }
4444
4445 ctxt->op_bytes = def_op_bytes;
4446 ctxt->ad_bytes = def_ad_bytes;
4447
4448 /* Legacy prefixes. */
4449 for (;;) {
4450 switch (ctxt->b = insn_fetch(u8, ctxt)) {
4451 case 0x66: /* operand-size override */
4452 op_prefix = true;
4453 /* switch between 2/4 bytes */
4454 ctxt->op_bytes = def_op_bytes ^ 6;
4455 break;
4456 case 0x67: /* address-size override */
4457 if (mode == X86EMUL_MODE_PROT64)
4458 /* switch between 4/8 bytes */
4459 ctxt->ad_bytes = def_ad_bytes ^ 12;
4460 else
4461 /* switch between 2/4 bytes */
4462 ctxt->ad_bytes = def_ad_bytes ^ 6;
4463 break;
4464 case 0x26: /* ES override */
4465 case 0x2e: /* CS override */
4466 case 0x36: /* SS override */
4467 case 0x3e: /* DS override */
4468 has_seg_override = true;
4469 ctxt->seg_override = (ctxt->b >> 3) & 3;
4470 break;
4471 case 0x64: /* FS override */
4472 case 0x65: /* GS override */
4473 has_seg_override = true;
4474 ctxt->seg_override = ctxt->b & 7;
4475 break;
4476 case 0x40 ... 0x4f: /* REX */
4477 if (mode != X86EMUL_MODE_PROT64)
4478 goto done_prefixes;
4479 ctxt->rex_prefix = ctxt->b;
4480 continue;
4481 case 0xf0: /* LOCK */
4482 ctxt->lock_prefix = 1;
4483 break;
4484 case 0xf2: /* REPNE/REPNZ */
4485 case 0xf3: /* REP/REPE/REPZ */
4486 ctxt->rep_prefix = ctxt->b;
4487 break;
4488 default:
4489 goto done_prefixes;
4490 }
4491
4492 /* Any legacy prefix after a REX prefix nullifies its effect. */
4493
4494 ctxt->rex_prefix = 0;
4495 }
4496
4497 done_prefixes:
4498
4499 /* REX prefix. */
4500 if (ctxt->rex_prefix & 8)
4501 ctxt->op_bytes = 8; /* REX.W */
4502
4503 /* Opcode byte(s). */
4504 opcode = opcode_table[ctxt->b];
4505 /* Two-byte opcode? */
4506 if (ctxt->b == 0x0f) {
4507 ctxt->opcode_len = 2;
4508 ctxt->b = insn_fetch(u8, ctxt);
4509 opcode = twobyte_table[ctxt->b];
4510
4511 /* 0F_38 opcode map */
4512 if (ctxt->b == 0x38) {
4513 ctxt->opcode_len = 3;
4514 ctxt->b = insn_fetch(u8, ctxt);
4515 opcode = opcode_map_0f_38[ctxt->b];
4516 }
4517 }
4518 ctxt->d = opcode.flags;
4519
4520 if (ctxt->d & ModRM)
4521 ctxt->modrm = insn_fetch(u8, ctxt);
4522
4523 /* vex-prefix instructions are not implemented */
4524 if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) &&
4525 (mode == X86EMUL_MODE_PROT64 || (ctxt->modrm & 0xc0) == 0xc0)) {
4526 ctxt->d = NotImpl;
4527 }
4528
4529 while (ctxt->d & GroupMask) {
4530 switch (ctxt->d & GroupMask) {
4531 case Group:
4532 goffset = (ctxt->modrm >> 3) & 7;
4533 opcode = opcode.u.group[goffset];
4534 break;
4535 case GroupDual:
4536 goffset = (ctxt->modrm >> 3) & 7;
4537 if ((ctxt->modrm >> 6) == 3)
4538 opcode = opcode.u.gdual->mod3[goffset];
4539 else
4540 opcode = opcode.u.gdual->mod012[goffset];
4541 break;
4542 case RMExt:
4543 goffset = ctxt->modrm & 7;
4544 opcode = opcode.u.group[goffset];
4545 break;
4546 case Prefix:
4547 if (ctxt->rep_prefix && op_prefix)
4548 return EMULATION_FAILED;
4549 simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
4550 switch (simd_prefix) {
4551 case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
4552 case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
4553 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
4554 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
4555 }
4556 break;
4557 case Escape:
4558 if (ctxt->modrm > 0xbf)
4559 opcode = opcode.u.esc->high[ctxt->modrm - 0xc0];
4560 else
4561 opcode = opcode.u.esc->op[(ctxt->modrm >> 3) & 7];
4562 break;
4563 case InstrDual:
4564 if ((ctxt->modrm >> 6) == 3)
4565 opcode = opcode.u.idual->mod3;
4566 else
4567 opcode = opcode.u.idual->mod012;
4568 break;
4569 default:
4570 return EMULATION_FAILED;
4571 }
4572
4573 ctxt->d &= ~(u64)GroupMask;
4574 ctxt->d |= opcode.flags;
4575 }
4576
4577 /* Unrecognised? */
4578 if (ctxt->d == 0)
4579 return EMULATION_FAILED;
4580
4581 ctxt->execute = opcode.u.execute;
4582
4583 if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD)))
4584 return EMULATION_FAILED;
4585
4586 if (unlikely(ctxt->d &
4587 (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm|NearBranch|
4588 No16))) {
4589 /*
4590 * These are copied unconditionally here, and checked unconditionally
4591 * in x86_emulate_insn.
4592 */
4593 ctxt->check_perm = opcode.check_perm;
4594 ctxt->intercept = opcode.intercept;
4595
4596 if (ctxt->d & NotImpl)
4597 return EMULATION_FAILED;
4598
4599 if (mode == X86EMUL_MODE_PROT64) {
4600 if (ctxt->op_bytes == 4 && (ctxt->d & Stack))
4601 ctxt->op_bytes = 8;
4602 else if (ctxt->d & NearBranch)
4603 ctxt->op_bytes = 8;
4604 }
4605
4606 if (ctxt->d & Op3264) {
4607 if (mode == X86EMUL_MODE_PROT64)
4608 ctxt->op_bytes = 8;
4609 else
4610 ctxt->op_bytes = 4;
4611 }
4612
4613 if ((ctxt->d & No16) && ctxt->op_bytes == 2)
4614 ctxt->op_bytes = 4;
4615
4616 if (ctxt->d & Sse)
4617 ctxt->op_bytes = 16;
4618 else if (ctxt->d & Mmx)
4619 ctxt->op_bytes = 8;
4620 }
4621
4622 /* ModRM and SIB bytes. */
4623 if (ctxt->d & ModRM) {
4624 rc = decode_modrm(ctxt, &ctxt->memop);
4625 if (!has_seg_override) {
4626 has_seg_override = true;
4627 ctxt->seg_override = ctxt->modrm_seg;
4628 }
4629 } else if (ctxt->d & MemAbs)
4630 rc = decode_abs(ctxt, &ctxt->memop);
4631 if (rc != X86EMUL_CONTINUE)
4632 goto done;
4633
4634 if (!has_seg_override)
4635 ctxt->seg_override = VCPU_SREG_DS;
4636
4637 ctxt->memop.addr.mem.seg = ctxt->seg_override;
4638
4639 /*
4640 * Decode and fetch the source operand: register, memory
4641 * or immediate.
4642 */
4643 rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask);
4644 if (rc != X86EMUL_CONTINUE)
4645 goto done;
4646
4647 /*
4648 * Decode and fetch the second source operand: register, memory
4649 * or immediate.
4650 */
4651 rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask);
4652 if (rc != X86EMUL_CONTINUE)
4653 goto done;
4654
4655 /* Decode and fetch the destination operand: register or memory. */
4656 rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
4657
4658 if (ctxt->rip_relative)
4659 ctxt->memopp->addr.mem.ea = address_mask(ctxt,
4660 ctxt->memopp->addr.mem.ea + ctxt->_eip);
4661
4662 done:
4663 return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
4664 }
4665
4666 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt)
4667 {
4668 return ctxt->d & PageTable;
4669 }
4670
4671 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
4672 {
4673 /* The second termination condition only applies for REPE
4674 * and REPNE. Test if the repeat string operation prefix is
4675 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
4676 * corresponding termination condition according to:
4677 * - if REPE/REPZ and ZF = 0 then done
4678 * - if REPNE/REPNZ and ZF = 1 then done
4679 */
4680 if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) ||
4681 (ctxt->b == 0xae) || (ctxt->b == 0xaf))
4682 && (((ctxt->rep_prefix == REPE_PREFIX) &&
4683 ((ctxt->eflags & EFLG_ZF) == 0))
4684 || ((ctxt->rep_prefix == REPNE_PREFIX) &&
4685 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
4686 return true;
4687
4688 return false;
4689 }
4690
4691 static int flush_pending_x87_faults(struct x86_emulate_ctxt *ctxt)
4692 {
4693 bool fault = false;
4694
4695 ctxt->ops->get_fpu(ctxt);
4696 asm volatile("1: fwait \n\t"
4697 "2: \n\t"
4698 ".pushsection .fixup,\"ax\" \n\t"
4699 "3: \n\t"
4700 "movb $1, %[fault] \n\t"
4701 "jmp 2b \n\t"
4702 ".popsection \n\t"
4703 _ASM_EXTABLE(1b, 3b)
4704 : [fault]"+qm"(fault));
4705 ctxt->ops->put_fpu(ctxt);
4706
4707 if (unlikely(fault))
4708 return emulate_exception(ctxt, MF_VECTOR, 0, false);
4709
4710 return X86EMUL_CONTINUE;
4711 }
4712
4713 static void fetch_possible_mmx_operand(struct x86_emulate_ctxt *ctxt,
4714 struct operand *op)
4715 {
4716 if (op->type == OP_MM)
4717 read_mmx_reg(ctxt, &op->mm_val, op->addr.mm);
4718 }
4719
4720 static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))
4721 {
4722 ulong flags = (ctxt->eflags & EFLAGS_MASK) | X86_EFLAGS_IF;
4723 if (!(ctxt->d & ByteOp))
4724 fop += __ffs(ctxt->dst.bytes) * FASTOP_SIZE;
4725 asm("push %[flags]; popf; call *%[fastop]; pushf; pop %[flags]\n"
4726 : "+a"(ctxt->dst.val), "+d"(ctxt->src.val), [flags]"+D"(flags),
4727 [fastop]"+S"(fop)
4728 : "c"(ctxt->src2.val));
4729 ctxt->eflags = (ctxt->eflags & ~EFLAGS_MASK) | (flags & EFLAGS_MASK);
4730 if (!fop) /* exception is returned in fop variable */
4731 return emulate_de(ctxt);
4732 return X86EMUL_CONTINUE;
4733 }
4734
4735 void init_decode_cache(struct x86_emulate_ctxt *ctxt)
4736 {
4737 memset(&ctxt->rip_relative, 0,
4738 (void *)&ctxt->modrm - (void *)&ctxt->rip_relative);
4739
4740 ctxt->io_read.pos = 0;
4741 ctxt->io_read.end = 0;
4742 ctxt->mem_read.end = 0;
4743 }
4744
4745 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
4746 {
4747 const struct x86_emulate_ops *ops = ctxt->ops;
4748 int rc = X86EMUL_CONTINUE;
4749 int saved_dst_type = ctxt->dst.type;
4750
4751 ctxt->mem_read.pos = 0;
4752
4753 /* LOCK prefix is allowed only with some instructions */
4754 if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) {
4755 rc = emulate_ud(ctxt);
4756 goto done;
4757 }
4758
4759 if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) {
4760 rc = emulate_ud(ctxt);
4761 goto done;
4762 }
4763
4764 if (unlikely(ctxt->d &
4765 (No64|Undefined|Sse|Mmx|Intercept|CheckPerm|Priv|Prot|String))) {
4766 if ((ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) ||
4767 (ctxt->d & Undefined)) {
4768 rc = emulate_ud(ctxt);
4769 goto done;
4770 }
4771
4772 if (((ctxt->d & (Sse|Mmx)) && ((ops->get_cr(ctxt, 0) & X86_CR0_EM)))
4773 || ((ctxt->d & Sse) && !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) {
4774 rc = emulate_ud(ctxt);
4775 goto done;
4776 }
4777
4778 if ((ctxt->d & (Sse|Mmx)) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) {
4779 rc = emulate_nm(ctxt);
4780 goto done;
4781 }
4782
4783 if (ctxt->d & Mmx) {
4784 rc = flush_pending_x87_faults(ctxt);
4785 if (rc != X86EMUL_CONTINUE)
4786 goto done;
4787 /*
4788 * Now that we know the fpu is exception safe, we can fetch
4789 * operands from it.
4790 */
4791 fetch_possible_mmx_operand(ctxt, &ctxt->src);
4792 fetch_possible_mmx_operand(ctxt, &ctxt->src2);
4793 if (!(ctxt->d & Mov))
4794 fetch_possible_mmx_operand(ctxt, &ctxt->dst);
4795 }
4796
4797 if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
4798 rc = emulator_check_intercept(ctxt, ctxt->intercept,
4799 X86_ICPT_PRE_EXCEPT);
4800 if (rc != X86EMUL_CONTINUE)
4801 goto done;
4802 }
4803
4804 /* Privileged instruction can be executed only in CPL=0 */
4805 if ((ctxt->d & Priv) && ops->cpl(ctxt)) {
4806 if (ctxt->d & PrivUD)
4807 rc = emulate_ud(ctxt);
4808 else
4809 rc = emulate_gp(ctxt, 0);
4810 goto done;
4811 }
4812
4813 /* Instruction can only be executed in protected mode */
4814 if ((ctxt->d & Prot) && ctxt->mode < X86EMUL_MODE_PROT16) {
4815 rc = emulate_ud(ctxt);
4816 goto done;
4817 }
4818
4819 /* Do instruction specific permission checks */
4820 if (ctxt->d & CheckPerm) {
4821 rc = ctxt->check_perm(ctxt);
4822 if (rc != X86EMUL_CONTINUE)
4823 goto done;
4824 }
4825
4826 if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
4827 rc = emulator_check_intercept(ctxt, ctxt->intercept,
4828 X86_ICPT_POST_EXCEPT);
4829 if (rc != X86EMUL_CONTINUE)
4830 goto done;
4831 }
4832
4833 if (ctxt->rep_prefix && (ctxt->d & String)) {
4834 /* All REP prefixes have the same first termination condition */
4835 if (address_mask(ctxt, reg_read(ctxt, VCPU_REGS_RCX)) == 0) {
4836 ctxt->eip = ctxt->_eip;
4837 ctxt->eflags &= ~EFLG_RF;
4838 goto done;
4839 }
4840 }
4841 }
4842
4843 if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) {
4844 rc = segmented_read(ctxt, ctxt->src.addr.mem,
4845 ctxt->src.valptr, ctxt->src.bytes);
4846 if (rc != X86EMUL_CONTINUE)
4847 goto done;
4848 ctxt->src.orig_val64 = ctxt->src.val64;
4849 }
4850
4851 if (ctxt->src2.type == OP_MEM) {
4852 rc = segmented_read(ctxt, ctxt->src2.addr.mem,
4853 &ctxt->src2.val, ctxt->src2.bytes);
4854 if (rc != X86EMUL_CONTINUE)
4855 goto done;
4856 }
4857
4858 if ((ctxt->d & DstMask) == ImplicitOps)
4859 goto special_insn;
4860
4861
4862 if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) {
4863 /* optimisation - avoid slow emulated read if Mov */
4864 rc = segmented_read(ctxt, ctxt->dst.addr.mem,
4865 &ctxt->dst.val, ctxt->dst.bytes);
4866 if (rc != X86EMUL_CONTINUE)
4867 goto done;
4868 }
4869 ctxt->dst.orig_val = ctxt->dst.val;
4870
4871 special_insn:
4872
4873 if (unlikely(ctxt->guest_mode) && (ctxt->d & Intercept)) {
4874 rc = emulator_check_intercept(ctxt, ctxt->intercept,
4875 X86_ICPT_POST_MEMACCESS);
4876 if (rc != X86EMUL_CONTINUE)
4877 goto done;
4878 }
4879
4880 if (ctxt->rep_prefix && (ctxt->d & String))
4881 ctxt->eflags |= EFLG_RF;
4882 else
4883 ctxt->eflags &= ~EFLG_RF;
4884
4885 if (ctxt->execute) {
4886 if (ctxt->d & Fastop) {
4887 void (*fop)(struct fastop *) = (void *)ctxt->execute;
4888 rc = fastop(ctxt, fop);
4889 if (rc != X86EMUL_CONTINUE)
4890 goto done;
4891 goto writeback;
4892 }
4893 rc = ctxt->execute(ctxt);
4894 if (rc != X86EMUL_CONTINUE)
4895 goto done;
4896 goto writeback;
4897 }
4898
4899 if (ctxt->opcode_len == 2)
4900 goto twobyte_insn;
4901 else if (ctxt->opcode_len == 3)
4902 goto threebyte_insn;
4903
4904 switch (ctxt->b) {
4905 case 0x63: /* movsxd */
4906 if (ctxt->mode != X86EMUL_MODE_PROT64)
4907 goto cannot_emulate;
4908 ctxt->dst.val = (s32) ctxt->src.val;
4909 break;
4910 case 0x70 ... 0x7f: /* jcc (short) */
4911 if (test_cc(ctxt->b, ctxt->eflags))
4912 rc = jmp_rel(ctxt, ctxt->src.val);
4913 break;
4914 case 0x8d: /* lea r16/r32, m */
4915 ctxt->dst.val = ctxt->src.addr.mem.ea;
4916 break;
4917 case 0x90 ... 0x97: /* nop / xchg reg, rax */
4918 if (ctxt->dst.addr.reg == reg_rmw(ctxt, VCPU_REGS_RAX))
4919 ctxt->dst.type = OP_NONE;
4920 else
4921 rc = em_xchg(ctxt);
4922 break;
4923 case 0x98: /* cbw/cwde/cdqe */
4924 switch (ctxt->op_bytes) {
4925 case 2: ctxt->dst.val = (s8)ctxt->dst.val; break;
4926 case 4: ctxt->dst.val = (s16)ctxt->dst.val; break;
4927 case 8: ctxt->dst.val = (s32)ctxt->dst.val; break;
4928 }
4929 break;
4930 case 0xcc: /* int3 */
4931 rc = emulate_int(ctxt, 3);
4932 break;
4933 case 0xcd: /* int n */
4934 rc = emulate_int(ctxt, ctxt->src.val);
4935 break;
4936 case 0xce: /* into */
4937 if (ctxt->eflags & EFLG_OF)
4938 rc = emulate_int(ctxt, 4);
4939 break;
4940 case 0xe9: /* jmp rel */
4941 case 0xeb: /* jmp rel short */
4942 rc = jmp_rel(ctxt, ctxt->src.val);
4943 ctxt->dst.type = OP_NONE; /* Disable writeback. */
4944 break;
4945 case 0xf4: /* hlt */
4946 ctxt->ops->halt(ctxt);
4947 break;
4948 case 0xf5: /* cmc */
4949 /* complement carry flag from eflags reg */
4950 ctxt->eflags ^= EFLG_CF;
4951 break;
4952 case 0xf8: /* clc */
4953 ctxt->eflags &= ~EFLG_CF;
4954 break;
4955 case 0xf9: /* stc */
4956 ctxt->eflags |= EFLG_CF;
4957 break;
4958 case 0xfc: /* cld */
4959 ctxt->eflags &= ~EFLG_DF;
4960 break;
4961 case 0xfd: /* std */
4962 ctxt->eflags |= EFLG_DF;
4963 break;
4964 default:
4965 goto cannot_emulate;
4966 }
4967
4968 if (rc != X86EMUL_CONTINUE)
4969 goto done;
4970
4971 writeback:
4972 if (ctxt->d & SrcWrite) {
4973 BUG_ON(ctxt->src.type == OP_MEM || ctxt->src.type == OP_MEM_STR);
4974 rc = writeback(ctxt, &ctxt->src);
4975 if (rc != X86EMUL_CONTINUE)
4976 goto done;
4977 }
4978 if (!(ctxt->d & NoWrite)) {
4979 rc = writeback(ctxt, &ctxt->dst);
4980 if (rc != X86EMUL_CONTINUE)
4981 goto done;
4982 }
4983
4984 /*
4985 * restore dst type in case the decoding will be reused
4986 * (happens for string instruction )
4987 */
4988 ctxt->dst.type = saved_dst_type;
4989
4990 if ((ctxt->d & SrcMask) == SrcSI)
4991 string_addr_inc(ctxt, VCPU_REGS_RSI, &ctxt->src);
4992
4993 if ((ctxt->d & DstMask) == DstDI)
4994 string_addr_inc(ctxt, VCPU_REGS_RDI, &ctxt->dst);
4995
4996 if (ctxt->rep_prefix && (ctxt->d & String)) {
4997 unsigned int count;
4998 struct read_cache *r = &ctxt->io_read;
4999 if ((ctxt->d & SrcMask) == SrcSI)
5000 count = ctxt->src.count;
5001 else
5002 count = ctxt->dst.count;
5003 register_address_increment(ctxt, VCPU_REGS_RCX, -count);
5004
5005 if (!string_insn_completed(ctxt)) {
5006 /*
5007 * Re-enter guest when pio read ahead buffer is empty
5008 * or, if it is not used, after each 1024 iteration.
5009 */
5010 if ((r->end != 0 || reg_read(ctxt, VCPU_REGS_RCX) & 0x3ff) &&
5011 (r->end == 0 || r->end != r->pos)) {
5012 /*
5013 * Reset read cache. Usually happens before
5014 * decode, but since instruction is restarted
5015 * we have to do it here.
5016 */
5017 ctxt->mem_read.end = 0;
5018 writeback_registers(ctxt);
5019 return EMULATION_RESTART;
5020 }
5021 goto done; /* skip rip writeback */
5022 }
5023 ctxt->eflags &= ~EFLG_RF;
5024 }
5025
5026 ctxt->eip = ctxt->_eip;
5027
5028 done:
5029 if (rc == X86EMUL_PROPAGATE_FAULT) {
5030 WARN_ON(ctxt->exception.vector > 0x1f);
5031 ctxt->have_exception = true;
5032 }
5033 if (rc == X86EMUL_INTERCEPTED)
5034 return EMULATION_INTERCEPTED;
5035
5036 if (rc == X86EMUL_CONTINUE)
5037 writeback_registers(ctxt);
5038
5039 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
5040
5041 twobyte_insn:
5042 switch (ctxt->b) {
5043 case 0x09: /* wbinvd */
5044 (ctxt->ops->wbinvd)(ctxt);
5045 break;
5046 case 0x08: /* invd */
5047 case 0x0d: /* GrpP (prefetch) */
5048 case 0x18: /* Grp16 (prefetch/nop) */
5049 case 0x1f: /* nop */
5050 break;
5051 case 0x20: /* mov cr, reg */
5052 ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg);
5053 break;
5054 case 0x21: /* mov from dr to reg */
5055 ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val);
5056 break;
5057 case 0x40 ... 0x4f: /* cmov */
5058 if (test_cc(ctxt->b, ctxt->eflags))
5059 ctxt->dst.val = ctxt->src.val;
5060 else if (ctxt->mode != X86EMUL_MODE_PROT64 ||
5061 ctxt->op_bytes != 4)
5062 ctxt->dst.type = OP_NONE; /* no writeback */
5063 break;
5064 case 0x80 ... 0x8f: /* jnz rel, etc*/
5065 if (test_cc(ctxt->b, ctxt->eflags))
5066 rc = jmp_rel(ctxt, ctxt->src.val);
5067 break;
5068 case 0x90 ... 0x9f: /* setcc r/m8 */
5069 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
5070 break;
5071 case 0xb6 ... 0xb7: /* movzx */
5072 ctxt->dst.bytes = ctxt->op_bytes;
5073 ctxt->dst.val = (ctxt->src.bytes == 1) ? (u8) ctxt->src.val
5074 : (u16) ctxt->src.val;
5075 break;
5076 case 0xbe ... 0xbf: /* movsx */
5077 ctxt->dst.bytes = ctxt->op_bytes;
5078 ctxt->dst.val = (ctxt->src.bytes == 1) ? (s8) ctxt->src.val :
5079 (s16) ctxt->src.val;
5080 break;
5081 default:
5082 goto cannot_emulate;
5083 }
5084
5085 threebyte_insn:
5086
5087 if (rc != X86EMUL_CONTINUE)
5088 goto done;
5089
5090 goto writeback;
5091
5092 cannot_emulate:
5093 return EMULATION_FAILED;
5094 }
5095
5096 void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt)
5097 {
5098 invalidate_registers(ctxt);
5099 }
5100
5101 void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt)
5102 {
5103 writeback_registers(ctxt);
5104 }
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