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MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / arch / x86 / kvm / emulate.c
blobf1e3be18a08ff9507ee98f1020896167efe36932
1 /******************************************************************************
2 * emulate.c
3 *
4 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
5 *
6 * Copyright (c) 2005 Keir Fraser
7 *
8 * Linux coding style, mod r/m decoder, segment base fixes, real-mode
9 * privileged instructions:
10 *
11 * Copyright (C) 2006 Qumranet
12 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
13 *
14 * Avi Kivity <avi@qumranet.com>
15 * Yaniv Kamay <yaniv@qumranet.com>
16 *
17 * This work is licensed under the terms of the GNU GPL, version 2. See
18 * the COPYING file in the top-level directory.
19 *
20 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
21 */
22
23 #include <linux/kvm_host.h>
24 #include "kvm_cache_regs.h"
25 #include <linux/module.h>
26 #include <asm/kvm_emulate.h>
27
28 #include "x86.h"
29 #include "tss.h"
30
31 /*
32 * Operand types
33 */
34 #define OpNone 0ull
35 #define OpImplicit 1ull /* No generic decode */
36 #define OpReg 2ull /* Register */
37 #define OpMem 3ull /* Memory */
38 #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */
39 #define OpDI 5ull /* ES:DI/EDI/RDI */
40 #define OpMem64 6ull /* Memory, 64-bit */
41 #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */
42 #define OpDX 8ull /* DX register */
43 #define OpCL 9ull /* CL register (for shifts) */
44 #define OpImmByte 10ull /* 8-bit sign extended immediate */
45 #define OpOne 11ull /* Implied 1 */
46 #define OpImm 12ull /* Sign extended immediate */
47 #define OpMem16 13ull /* Memory operand (16-bit). */
48 #define OpMem32 14ull /* Memory operand (32-bit). */
49 #define OpImmU 15ull /* Immediate operand, zero extended */
50 #define OpSI 16ull /* SI/ESI/RSI */
51 #define OpImmFAddr 17ull /* Immediate far address */
52 #define OpMemFAddr 18ull /* Far address in memory */
53 #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */
54 #define OpES 20ull /* ES */
55 #define OpCS 21ull /* CS */
56 #define OpSS 22ull /* SS */
57 #define OpDS 23ull /* DS */
58 #define OpFS 24ull /* FS */
59 #define OpGS 25ull /* GS */
60
61 #define OpBits 5 /* Width of operand field */
62 #define OpMask ((1ull << OpBits) - 1)
63
64 /*
65 * Opcode effective-address decode tables.
66 * Note that we only emulate instructions that have at least one memory
67 * operand (excluding implicit stack references). We assume that stack
68 * references and instruction fetches will never occur in special memory
69 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
70 * not be handled.
71 */
72
73 /* Operand sizes: 8-bit operands or specified/overridden size. */
74 #define ByteOp (1<<0) /* 8-bit operands. */
75 /* Destination operand type. */
76 #define DstShift 1
77 #define ImplicitOps (OpImplicit << DstShift)
78 #define DstReg (OpReg << DstShift)
79 #define DstMem (OpMem << DstShift)
80 #define DstAcc (OpAcc << DstShift)
81 #define DstDI (OpDI << DstShift)
82 #define DstMem64 (OpMem64 << DstShift)
83 #define DstImmUByte (OpImmUByte << DstShift)
84 #define DstDX (OpDX << DstShift)
85 #define DstMask (OpMask << DstShift)
86 /* Source operand type. */
87 #define SrcShift 6
88 #define SrcNone (OpNone << SrcShift)
89 #define SrcReg (OpReg << SrcShift)
90 #define SrcMem (OpMem << SrcShift)
91 #define SrcMem16 (OpMem16 << SrcShift)
92 #define SrcMem32 (OpMem32 << SrcShift)
93 #define SrcImm (OpImm << SrcShift)
94 #define SrcImmByte (OpImmByte << SrcShift)
95 #define SrcOne (OpOne << SrcShift)
96 #define SrcImmUByte (OpImmUByte << SrcShift)
97 #define SrcImmU (OpImmU << SrcShift)
98 #define SrcSI (OpSI << SrcShift)
99 #define SrcImmFAddr (OpImmFAddr << SrcShift)
100 #define SrcMemFAddr (OpMemFAddr << SrcShift)
101 #define SrcAcc (OpAcc << SrcShift)
102 #define SrcImmU16 (OpImmU16 << SrcShift)
103 #define SrcDX (OpDX << SrcShift)
104 #define SrcMask (OpMask << SrcShift)
105 #define BitOp (1<<11)
106 #define MemAbs (1<<12) /* Memory operand is absolute displacement */
107 #define String (1<<13) /* String instruction (rep capable) */
108 #define Stack (1<<14) /* Stack instruction (push/pop) */
109 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */
110 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */
111 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */
112 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */
113 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */
114 #define Sse (1<<18) /* SSE Vector instruction */
115 /* Generic ModRM decode. */
116 #define ModRM (1<<19)
117 /* Destination is only written; never read. */
118 #define Mov (1<<20)
119 /* Misc flags */
120 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */
121 #define VendorSpecific (1<<22) /* Vendor specific instruction */
122 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
123 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */
124 #define Undefined (1<<25) /* No Such Instruction */
125 #define Lock (1<<26) /* lock prefix is allowed for the instruction */
126 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
127 #define No64 (1<<28)
128 /* Source 2 operand type */
129 #define Src2Shift (29)
130 #define Src2None (OpNone << Src2Shift)
131 #define Src2CL (OpCL << Src2Shift)
132 #define Src2ImmByte (OpImmByte << Src2Shift)
133 #define Src2One (OpOne << Src2Shift)
134 #define Src2Imm (OpImm << Src2Shift)
135 #define Src2ES (OpES << Src2Shift)
136 #define Src2CS (OpCS << Src2Shift)
137 #define Src2SS (OpSS << Src2Shift)
138 #define Src2DS (OpDS << Src2Shift)
139 #define Src2FS (OpFS << Src2Shift)
140 #define Src2GS (OpGS << Src2Shift)
141 #define Src2Mask (OpMask << Src2Shift)
142
143 #define X2(x...) x, x
144 #define X3(x...) X2(x), x
145 #define X4(x...) X2(x), X2(x)
146 #define X5(x...) X4(x), x
147 #define X6(x...) X4(x), X2(x)
148 #define X7(x...) X4(x), X3(x)
149 #define X8(x...) X4(x), X4(x)
150 #define X16(x...) X8(x), X8(x)
151
152 struct opcode {
153 u64 flags : 56;
154 u64 intercept : 8;
155 union {
156 int (*execute)(struct x86_emulate_ctxt *ctxt);
157 struct opcode *group;
158 struct group_dual *gdual;
159 struct gprefix *gprefix;
160 } u;
161 int (*check_perm)(struct x86_emulate_ctxt *ctxt);
162 };
163
164 struct group_dual {
165 struct opcode mod012[8];
166 struct opcode mod3[8];
167 };
168
169 struct gprefix {
170 struct opcode pfx_no;
171 struct opcode pfx_66;
172 struct opcode pfx_f2;
173 struct opcode pfx_f3;
174 };
175
176 /* EFLAGS bit definitions. */
177 #define EFLG_ID (1<<21)
178 #define EFLG_VIP (1<<20)
179 #define EFLG_VIF (1<<19)
180 #define EFLG_AC (1<<18)
181 #define EFLG_VM (1<<17)
182 #define EFLG_RF (1<<16)
183 #define EFLG_IOPL (3<<12)
184 #define EFLG_NT (1<<14)
185 #define EFLG_OF (1<<11)
186 #define EFLG_DF (1<<10)
187 #define EFLG_IF (1<<9)
188 #define EFLG_TF (1<<8)
189 #define EFLG_SF (1<<7)
190 #define EFLG_ZF (1<<6)
191 #define EFLG_AF (1<<4)
192 #define EFLG_PF (1<<2)
193 #define EFLG_CF (1<<0)
194
195 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a
196 #define EFLG_RESERVED_ONE_MASK 2
197
198 /*
199 * Instruction emulation:
200 * Most instructions are emulated directly via a fragment of inline assembly
201 * code. This allows us to save/restore EFLAGS and thus very easily pick up
202 * any modified flags.
203 */
204
205 #if defined(CONFIG_X86_64)
206 #define _LO32 "k" /* force 32-bit operand */
207 #define _STK "%%rsp" /* stack pointer */
208 #elif defined(__i386__)
209 #define _LO32 "" /* force 32-bit operand */
210 #define _STK "%%esp" /* stack pointer */
211 #endif
212
213 /*
214 * These EFLAGS bits are restored from saved value during emulation, and
215 * any changes are written back to the saved value after emulation.
216 */
217 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
218
219 /* Before executing instruction: restore necessary bits in EFLAGS. */
220 #define _PRE_EFLAGS(_sav, _msk, _tmp) \
221 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \
222 "movl %"_sav",%"_LO32 _tmp"; " \
223 "push %"_tmp"; " \
224 "push %"_tmp"; " \
225 "movl %"_msk",%"_LO32 _tmp"; " \
226 "andl %"_LO32 _tmp",("_STK"); " \
227 "pushf; " \
228 "notl %"_LO32 _tmp"; " \
229 "andl %"_LO32 _tmp",("_STK"); " \
230 "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \
231 "pop %"_tmp"; " \
232 "orl %"_LO32 _tmp",("_STK"); " \
233 "popf; " \
234 "pop %"_sav"; "
235
236 /* After executing instruction: write-back necessary bits in EFLAGS. */
237 #define _POST_EFLAGS(_sav, _msk, _tmp) \
238 /* _sav |= EFLAGS & _msk; */ \
239 "pushf; " \
240 "pop %"_tmp"; " \
241 "andl %"_msk",%"_LO32 _tmp"; " \
242 "orl %"_LO32 _tmp",%"_sav"; "
243
244 #ifdef CONFIG_X86_64
245 #define ON64(x) x
246 #else
247 #define ON64(x)
248 #endif
249
250 #define ____emulate_2op(ctxt, _op, _x, _y, _suffix, _dsttype) \
251 do { \
252 __asm__ __volatile__ ( \
253 _PRE_EFLAGS("0", "4", "2") \
254 _op _suffix " %"_x"3,%1; " \
255 _POST_EFLAGS("0", "4", "2") \
256 : "=m" ((ctxt)->eflags), \
257 "+q" (*(_dsttype*)&(ctxt)->dst.val), \
258 "=&r" (_tmp) \
259 : _y ((ctxt)->src.val), "i" (EFLAGS_MASK)); \
260 } while (0)
261
262
263 /* Raw emulation: instruction has two explicit operands. */
264 #define __emulate_2op_nobyte(ctxt,_op,_wx,_wy,_lx,_ly,_qx,_qy) \
265 do { \
266 unsigned long _tmp; \
267 \
268 switch ((ctxt)->dst.bytes) { \
269 case 2: \
270 ____emulate_2op(ctxt,_op,_wx,_wy,"w",u16); \
271 break; \
272 case 4: \
273 ____emulate_2op(ctxt,_op,_lx,_ly,"l",u32); \
274 break; \
275 case 8: \
276 ON64(____emulate_2op(ctxt,_op,_qx,_qy,"q",u64)); \
277 break; \
278 } \
279 } while (0)
280
281 #define __emulate_2op(ctxt,_op,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \
282 do { \
283 unsigned long _tmp; \
284 switch ((ctxt)->dst.bytes) { \
285 case 1: \
286 ____emulate_2op(ctxt,_op,_bx,_by,"b",u8); \
287 break; \
288 default: \
289 __emulate_2op_nobyte(ctxt, _op, \
290 _wx, _wy, _lx, _ly, _qx, _qy); \
291 break; \
292 } \
293 } while (0)
294
295 /* Source operand is byte-sized and may be restricted to just %cl. */
296 #define emulate_2op_SrcB(ctxt, _op) \
297 __emulate_2op(ctxt, _op, "b", "c", "b", "c", "b", "c", "b", "c")
298
299 /* Source operand is byte, word, long or quad sized. */
300 #define emulate_2op_SrcV(ctxt, _op) \
301 __emulate_2op(ctxt, _op, "b", "q", "w", "r", _LO32, "r", "", "r")
302
303 /* Source operand is word, long or quad sized. */
304 #define emulate_2op_SrcV_nobyte(ctxt, _op) \
305 __emulate_2op_nobyte(ctxt, _op, "w", "r", _LO32, "r", "", "r")
306
307 /* Instruction has three operands and one operand is stored in ECX register */
308 #define __emulate_2op_cl(ctxt, _op, _suffix, _type) \
309 do { \
310 unsigned long _tmp; \
311 _type _clv = (ctxt)->src2.val; \
312 _type _srcv = (ctxt)->src.val; \
313 _type _dstv = (ctxt)->dst.val; \
314 \
315 __asm__ __volatile__ ( \
316 _PRE_EFLAGS("0", "5", "2") \
317 _op _suffix " %4,%1 \n" \
318 _POST_EFLAGS("0", "5", "2") \
319 : "=m" ((ctxt)->eflags), "+r" (_dstv), "=&r" (_tmp) \
320 : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \
321 ); \
322 \
323 (ctxt)->src2.val = (unsigned long) _clv; \
324 (ctxt)->src2.val = (unsigned long) _srcv; \
325 (ctxt)->dst.val = (unsigned long) _dstv; \
326 } while (0)
327
328 #define emulate_2op_cl(ctxt, _op) \
329 do { \
330 switch ((ctxt)->dst.bytes) { \
331 case 2: \
332 __emulate_2op_cl(ctxt, _op, "w", u16); \
333 break; \
334 case 4: \
335 __emulate_2op_cl(ctxt, _op, "l", u32); \
336 break; \
337 case 8: \
338 ON64(__emulate_2op_cl(ctxt, _op, "q", ulong)); \
339 break; \
340 } \
341 } while (0)
342
343 #define __emulate_1op(ctxt, _op, _suffix) \
344 do { \
345 unsigned long _tmp; \
346 \
347 __asm__ __volatile__ ( \
348 _PRE_EFLAGS("0", "3", "2") \
349 _op _suffix " %1; " \
350 _POST_EFLAGS("0", "3", "2") \
351 : "=m" ((ctxt)->eflags), "+m" ((ctxt)->dst.val), \
352 "=&r" (_tmp) \
353 : "i" (EFLAGS_MASK)); \
354 } while (0)
355
356 /* Instruction has only one explicit operand (no source operand). */
357 #define emulate_1op(ctxt, _op) \
358 do { \
359 switch ((ctxt)->dst.bytes) { \
360 case 1: __emulate_1op(ctxt, _op, "b"); break; \
361 case 2: __emulate_1op(ctxt, _op, "w"); break; \
362 case 4: __emulate_1op(ctxt, _op, "l"); break; \
363 case 8: ON64(__emulate_1op(ctxt, _op, "q")); break; \
364 } \
365 } while (0)
366
367 #define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \
368 do { \
369 unsigned long _tmp; \
370 ulong *rax = &(ctxt)->regs[VCPU_REGS_RAX]; \
371 ulong *rdx = &(ctxt)->regs[VCPU_REGS_RDX]; \
372 \
373 __asm__ __volatile__ ( \
374 _PRE_EFLAGS("0", "5", "1") \
375 "1: \n\t" \
376 _op _suffix " %6; " \
377 "2: \n\t" \
378 _POST_EFLAGS("0", "5", "1") \
379 ".pushsection .fixup,\"ax\" \n\t" \
380 "3: movb $1, %4 \n\t" \
381 "jmp 2b \n\t" \
382 ".popsection \n\t" \
383 _ASM_EXTABLE(1b, 3b) \
384 : "=m" ((ctxt)->eflags), "=&r" (_tmp), \
385 "+a" (*rax), "+d" (*rdx), "+qm"(_ex) \
386 : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val), \
387 "a" (*rax), "d" (*rdx)); \
388 } while (0)
389
390 /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */
391 #define emulate_1op_rax_rdx(ctxt, _op, _ex) \
392 do { \
393 switch((ctxt)->src.bytes) { \
394 case 1: \
395 __emulate_1op_rax_rdx(ctxt, _op, "b", _ex); \
396 break; \
397 case 2: \
398 __emulate_1op_rax_rdx(ctxt, _op, "w", _ex); \
399 break; \
400 case 4: \
401 __emulate_1op_rax_rdx(ctxt, _op, "l", _ex); \
402 break; \
403 case 8: ON64( \
404 __emulate_1op_rax_rdx(ctxt, _op, "q", _ex)); \
405 break; \
406 } \
407 } while (0)
408
409 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
410 enum x86_intercept intercept,
411 enum x86_intercept_stage stage)
412 {
413 struct x86_instruction_info info = {
414 .intercept = intercept,
415 .rep_prefix = ctxt->rep_prefix,
416 .modrm_mod = ctxt->modrm_mod,
417 .modrm_reg = ctxt->modrm_reg,
418 .modrm_rm = ctxt->modrm_rm,
419 .src_val = ctxt->src.val64,
420 .src_bytes = ctxt->src.bytes,
421 .dst_bytes = ctxt->dst.bytes,
422 .ad_bytes = ctxt->ad_bytes,
423 .next_rip = ctxt->eip,
424 };
425
426 return ctxt->ops->intercept(ctxt, &info, stage);
427 }
428
429 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
430 {
431 return (1UL << (ctxt->ad_bytes << 3)) - 1;
432 }
433
434 /* Access/update address held in a register, based on addressing mode. */
435 static inline unsigned long
436 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg)
437 {
438 if (ctxt->ad_bytes == sizeof(unsigned long))
439 return reg;
440 else
441 return reg & ad_mask(ctxt);
442 }
443
444 static inline unsigned long
445 register_address(struct x86_emulate_ctxt *ctxt, unsigned long reg)
446 {
447 return address_mask(ctxt, reg);
448 }
449
450 static inline void
451 register_address_increment(struct x86_emulate_ctxt *ctxt, unsigned long *reg, int inc)
452 {
453 if (ctxt->ad_bytes == sizeof(unsigned long))
454 *reg += inc;
455 else
456 *reg = (*reg & ~ad_mask(ctxt)) | ((*reg + inc) & ad_mask(ctxt));
457 }
458
459 static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
460 {
461 register_address_increment(ctxt, &ctxt->_eip, rel);
462 }
463
464 static u32 desc_limit_scaled(struct desc_struct *desc)
465 {
466 u32 limit = get_desc_limit(desc);
467
468 return desc->g ? (limit << 12) | 0xfff : limit;
469 }
470
471 static void set_seg_override(struct x86_emulate_ctxt *ctxt, int seg)
472 {
473 ctxt->has_seg_override = true;
474 ctxt->seg_override = seg;
475 }
476
477 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
478 {
479 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
480 return 0;
481
482 return ctxt->ops->get_cached_segment_base(ctxt, seg);
483 }
484
485 static unsigned seg_override(struct x86_emulate_ctxt *ctxt)
486 {
487 if (!ctxt->has_seg_override)
488 return 0;
489
490 return ctxt->seg_override;
491 }
492
493 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
494 u32 error, bool valid)
495 {
496 ctxt->exception.vector = vec;
497 ctxt->exception.error_code = error;
498 ctxt->exception.error_code_valid = valid;
499 return X86EMUL_PROPAGATE_FAULT;
500 }
501
502 static int emulate_db(struct x86_emulate_ctxt *ctxt)
503 {
504 return emulate_exception(ctxt, DB_VECTOR, 0, false);
505 }
506
507 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
508 {
509 return emulate_exception(ctxt, GP_VECTOR, err, true);
510 }
511
512 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err)
513 {
514 return emulate_exception(ctxt, SS_VECTOR, err, true);
515 }
516
517 static int emulate_ud(struct x86_emulate_ctxt *ctxt)
518 {
519 return emulate_exception(ctxt, UD_VECTOR, 0, false);
520 }
521
522 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)
523 {
524 return emulate_exception(ctxt, TS_VECTOR, err, true);
525 }
526
527 static int emulate_de(struct x86_emulate_ctxt *ctxt)
528 {
529 return emulate_exception(ctxt, DE_VECTOR, 0, false);
530 }
531
532 static int emulate_nm(struct x86_emulate_ctxt *ctxt)
533 {
534 return emulate_exception(ctxt, NM_VECTOR, 0, false);
535 }
536
537 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
538 {
539 u16 selector;
540 struct desc_struct desc;
541
542 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg);
543 return selector;
544 }
545
546 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector,
547 unsigned seg)
548 {
549 u16 dummy;
550 u32 base3;
551 struct desc_struct desc;
552
553 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg);
554 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg);
555 }
556
557 static int __linearize(struct x86_emulate_ctxt *ctxt,
558 struct segmented_address addr,
559 unsigned size, bool write, bool fetch,
560 ulong *linear)
561 {
562 struct desc_struct desc;
563 bool usable;
564 ulong la;
565 u32 lim;
566 u16 sel;
567 unsigned cpl, rpl;
568
569 la = seg_base(ctxt, addr.seg) + addr.ea;
570 switch (ctxt->mode) {
571 case X86EMUL_MODE_REAL:
572 break;
573 case X86EMUL_MODE_PROT64:
574 if (((signed long)la << 16) >> 16 != la)
575 return emulate_gp(ctxt, 0);
576 break;
577 default:
578 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
579 addr.seg);
580 if (!usable)
581 goto bad;
582 /* code segment or read-only data segment */
583 if (((desc.type & 8) || !(desc.type & 2)) && write)
584 goto bad;
585 /* unreadable code segment */
586 if (!fetch && (desc.type & 8) && !(desc.type & 2))
587 goto bad;
588 lim = desc_limit_scaled(&desc);
589 if ((desc.type & 8) || !(desc.type & 4)) {
590 /* expand-up segment */
591 if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim)
592 goto bad;
593 } else {
594 /* exapand-down segment */
595 if (addr.ea <= lim || (u32)(addr.ea + size - 1) <= lim)
596 goto bad;
597 lim = desc.d ? 0xffffffff : 0xffff;
598 if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim)
599 goto bad;
600 }
601 cpl = ctxt->ops->cpl(ctxt);
602 rpl = sel & 3;
603 cpl = max(cpl, rpl);
604 if (!(desc.type & 8)) {
605 /* data segment */
606 if (cpl > desc.dpl)
607 goto bad;
608 } else if ((desc.type & 8) && !(desc.type & 4)) {
609 /* nonconforming code segment */
610 if (cpl != desc.dpl)
611 goto bad;
612 } else if ((desc.type & 8) && (desc.type & 4)) {
613 /* conforming code segment */
614 if (cpl < desc.dpl)
615 goto bad;
616 }
617 break;
618 }
619 if (fetch ? ctxt->mode != X86EMUL_MODE_PROT64 : ctxt->ad_bytes != 8)
620 la &= (u32)-1;
621 *linear = la;
622 return X86EMUL_CONTINUE;
623 bad:
624 if (addr.seg == VCPU_SREG_SS)
625 return emulate_ss(ctxt, addr.seg);
626 else
627 return emulate_gp(ctxt, addr.seg);
628 }
629
630 static int linearize(struct x86_emulate_ctxt *ctxt,
631 struct segmented_address addr,
632 unsigned size, bool write,
633 ulong *linear)
634 {
635 return __linearize(ctxt, addr, size, write, false, linear);
636 }
637
638
639 static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
640 struct segmented_address addr,
641 void *data,
642 unsigned size)
643 {
644 int rc;
645 ulong linear;
646
647 rc = linearize(ctxt, addr, size, false, &linear);
648 if (rc != X86EMUL_CONTINUE)
649 return rc;
650 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
651 }
652
653 /*
654 * Fetch the next byte of the instruction being emulated which is pointed to
655 * by ctxt->_eip, then increment ctxt->_eip.
656 *
657 * Also prefetch the remaining bytes of the instruction without crossing page
658 * boundary if they are not in fetch_cache yet.
659 */
660 static int do_insn_fetch_byte(struct x86_emulate_ctxt *ctxt, u8 *dest)
661 {
662 struct fetch_cache *fc = &ctxt->fetch;
663 int rc;
664 int size, cur_size;
665
666 if (ctxt->_eip == fc->end) {
667 unsigned long linear;
668 struct segmented_address addr = { .seg = VCPU_SREG_CS,
669 .ea = ctxt->_eip };
670 cur_size = fc->end - fc->start;
671 size = min(15UL - cur_size,
672 PAGE_SIZE - offset_in_page(ctxt->_eip));
673 rc = __linearize(ctxt, addr, size, false, true, &linear);
674 if (unlikely(rc != X86EMUL_CONTINUE))
675 return rc;
676 rc = ctxt->ops->fetch(ctxt, linear, fc->data + cur_size,
677 size, &ctxt->exception);
678 if (unlikely(rc != X86EMUL_CONTINUE))
679 return rc;
680 fc->end += size;
681 }
682 *dest = fc->data[ctxt->_eip - fc->start];
683 ctxt->_eip++;
684 return X86EMUL_CONTINUE;
685 }
686
687 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt,
688 void *dest, unsigned size)
689 {
690 int rc;
691
692 /* x86 instructions are limited to 15 bytes. */
693 if (unlikely(ctxt->_eip + size - ctxt->eip > 15))
694 return X86EMUL_UNHANDLEABLE;
695 while (size--) {
696 rc = do_insn_fetch_byte(ctxt, dest++);
697 if (rc != X86EMUL_CONTINUE)
698 return rc;
699 }
700 return X86EMUL_CONTINUE;
701 }
702
703 /* Fetch next part of the instruction being emulated. */
704 #define insn_fetch(_type, _ctxt) \
705 ({ unsigned long _x; \
706 rc = do_insn_fetch(_ctxt, &_x, sizeof(_type)); \
707 if (rc != X86EMUL_CONTINUE) \
708 goto done; \
709 (_type)_x; \
710 })
711
712 #define insn_fetch_arr(_arr, _size, _ctxt) \
713 ({ rc = do_insn_fetch(_ctxt, _arr, (_size)); \
714 if (rc != X86EMUL_CONTINUE) \
715 goto done; \
716 })
717
718 /*
719 * Given the 'reg' portion of a ModRM byte, and a register block, return a
720 * pointer into the block that addresses the relevant register.
721 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
722 */
723 static void *decode_register(u8 modrm_reg, unsigned long *regs,
724 int highbyte_regs)
725 {
726 void *p;
727
728 p = &regs[modrm_reg];
729 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
730 p = (unsigned char *)&regs[modrm_reg & 3] + 1;
731 return p;
732 }
733
734 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
735 struct segmented_address addr,
736 u16 *size, unsigned long *address, int op_bytes)
737 {
738 int rc;
739
740 if (op_bytes == 2)
741 op_bytes = 3;
742 *address = 0;
743 rc = segmented_read_std(ctxt, addr, size, 2);
744 if (rc != X86EMUL_CONTINUE)
745 return rc;
746 addr.ea += 2;
747 rc = segmented_read_std(ctxt, addr, address, op_bytes);
748 return rc;
749 }
750
751 static int test_cc(unsigned int condition, unsigned int flags)
752 {
753 int rc = 0;
754
755 switch ((condition & 15) >> 1) {
756 case 0: /* o */
757 rc |= (flags & EFLG_OF);
758 break;
759 case 1: /* b/c/nae */
760 rc |= (flags & EFLG_CF);
761 break;
762 case 2: /* z/e */
763 rc |= (flags & EFLG_ZF);
764 break;
765 case 3: /* be/na */
766 rc |= (flags & (EFLG_CF|EFLG_ZF));
767 break;
768 case 4: /* s */
769 rc |= (flags & EFLG_SF);
770 break;
771 case 5: /* p/pe */
772 rc |= (flags & EFLG_PF);
773 break;
774 case 7: /* le/ng */
775 rc |= (flags & EFLG_ZF);
776 /* fall through */
777 case 6: /* l/nge */
778 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
779 break;
780 }
781
782 /* Odd condition identifiers (lsb == 1) have inverted sense. */
783 return (!!rc ^ (condition & 1));
784 }
785
786 static void fetch_register_operand(struct operand *op)
787 {
788 switch (op->bytes) {
789 case 1:
790 op->val = *(u8 *)op->addr.reg;
791 break;
792 case 2:
793 op->val = *(u16 *)op->addr.reg;
794 break;
795 case 4:
796 op->val = *(u32 *)op->addr.reg;
797 break;
798 case 8:
799 op->val = *(u64 *)op->addr.reg;
800 break;
801 }
802 }
803
804 static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
805 {
806 ctxt->ops->get_fpu(ctxt);
807 switch (reg) {
808 case 0: asm("movdqu %%xmm0, %0" : "=m"(*data)); break;
809 case 1: asm("movdqu %%xmm1, %0" : "=m"(*data)); break;
810 case 2: asm("movdqu %%xmm2, %0" : "=m"(*data)); break;
811 case 3: asm("movdqu %%xmm3, %0" : "=m"(*data)); break;
812 case 4: asm("movdqu %%xmm4, %0" : "=m"(*data)); break;
813 case 5: asm("movdqu %%xmm5, %0" : "=m"(*data)); break;
814 case 6: asm("movdqu %%xmm6, %0" : "=m"(*data)); break;
815 case 7: asm("movdqu %%xmm7, %0" : "=m"(*data)); break;
816 #ifdef CONFIG_X86_64
817 case 8: asm("movdqu %%xmm8, %0" : "=m"(*data)); break;
818 case 9: asm("movdqu %%xmm9, %0" : "=m"(*data)); break;
819 case 10: asm("movdqu %%xmm10, %0" : "=m"(*data)); break;
820 case 11: asm("movdqu %%xmm11, %0" : "=m"(*data)); break;
821 case 12: asm("movdqu %%xmm12, %0" : "=m"(*data)); break;
822 case 13: asm("movdqu %%xmm13, %0" : "=m"(*data)); break;
823 case 14: asm("movdqu %%xmm14, %0" : "=m"(*data)); break;
824 case 15: asm("movdqu %%xmm15, %0" : "=m"(*data)); break;
825 #endif
826 default: BUG();
827 }
828 ctxt->ops->put_fpu(ctxt);
829 }
830
831 static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
832 int reg)
833 {
834 ctxt->ops->get_fpu(ctxt);
835 switch (reg) {
836 case 0: asm("movdqu %0, %%xmm0" : : "m"(*data)); break;
837 case 1: asm("movdqu %0, %%xmm1" : : "m"(*data)); break;
838 case 2: asm("movdqu %0, %%xmm2" : : "m"(*data)); break;
839 case 3: asm("movdqu %0, %%xmm3" : : "m"(*data)); break;
840 case 4: asm("movdqu %0, %%xmm4" : : "m"(*data)); break;
841 case 5: asm("movdqu %0, %%xmm5" : : "m"(*data)); break;
842 case 6: asm("movdqu %0, %%xmm6" : : "m"(*data)); break;
843 case 7: asm("movdqu %0, %%xmm7" : : "m"(*data)); break;
844 #ifdef CONFIG_X86_64
845 case 8: asm("movdqu %0, %%xmm8" : : "m"(*data)); break;
846 case 9: asm("movdqu %0, %%xmm9" : : "m"(*data)); break;
847 case 10: asm("movdqu %0, %%xmm10" : : "m"(*data)); break;
848 case 11: asm("movdqu %0, %%xmm11" : : "m"(*data)); break;
849 case 12: asm("movdqu %0, %%xmm12" : : "m"(*data)); break;
850 case 13: asm("movdqu %0, %%xmm13" : : "m"(*data)); break;
851 case 14: asm("movdqu %0, %%xmm14" : : "m"(*data)); break;
852 case 15: asm("movdqu %0, %%xmm15" : : "m"(*data)); break;
853 #endif
854 default: BUG();
855 }
856 ctxt->ops->put_fpu(ctxt);
857 }
858
859 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
860 struct operand *op,
861 int inhibit_bytereg)
862 {
863 unsigned reg = ctxt->modrm_reg;
864 int highbyte_regs = ctxt->rex_prefix == 0;
865
866 if (!(ctxt->d & ModRM))
867 reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3);
868
869 if (ctxt->d & Sse) {
870 op->type = OP_XMM;
871 op->bytes = 16;
872 op->addr.xmm = reg;
873 read_sse_reg(ctxt, &op->vec_val, reg);
874 return;
875 }
876
877 op->type = OP_REG;
878 if ((ctxt->d & ByteOp) && !inhibit_bytereg) {
879 op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);
880 op->bytes = 1;
881 } else {
882 op->addr.reg = decode_register(reg, ctxt->regs, 0);
883 op->bytes = ctxt->op_bytes;
884 }
885 fetch_register_operand(op);
886 op->orig_val = op->val;
887 }
888
889 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
890 struct operand *op)
891 {
892 u8 sib;
893 int index_reg = 0, base_reg = 0, scale;
894 int rc = X86EMUL_CONTINUE;
895 ulong modrm_ea = 0;
896
897 if (ctxt->rex_prefix) {
898 ctxt->modrm_reg = (ctxt->rex_prefix & 4) << 1; /* REX.R */
899 index_reg = (ctxt->rex_prefix & 2) << 2; /* REX.X */
900 ctxt->modrm_rm = base_reg = (ctxt->rex_prefix & 1) << 3; /* REG.B */
901 }
902
903 ctxt->modrm = insn_fetch(u8, ctxt);
904 ctxt->modrm_mod |= (ctxt->modrm & 0xc0) >> 6;
905 ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3;
906 ctxt->modrm_rm |= (ctxt->modrm & 0x07);
907 ctxt->modrm_seg = VCPU_SREG_DS;
908
909 if (ctxt->modrm_mod == 3) {
910 op->type = OP_REG;
911 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
912 op->addr.reg = decode_register(ctxt->modrm_rm,
913 ctxt->regs, ctxt->d & ByteOp);
914 if (ctxt->d & Sse) {
915 op->type = OP_XMM;
916 op->bytes = 16;
917 op->addr.xmm = ctxt->modrm_rm;
918 read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
919 return rc;
920 }
921 fetch_register_operand(op);
922 return rc;
923 }
924
925 op->type = OP_MEM;
926
927 if (ctxt->ad_bytes == 2) {
928 unsigned bx = ctxt->regs[VCPU_REGS_RBX];
929 unsigned bp = ctxt->regs[VCPU_REGS_RBP];
930 unsigned si = ctxt->regs[VCPU_REGS_RSI];
931 unsigned di = ctxt->regs[VCPU_REGS_RDI];
932
933 /* 16-bit ModR/M decode. */
934 switch (ctxt->modrm_mod) {
935 case 0:
936 if (ctxt->modrm_rm == 6)
937 modrm_ea += insn_fetch(u16, ctxt);
938 break;
939 case 1:
940 modrm_ea += insn_fetch(s8, ctxt);
941 break;
942 case 2:
943 modrm_ea += insn_fetch(u16, ctxt);
944 break;
945 }
946 switch (ctxt->modrm_rm) {
947 case 0:
948 modrm_ea += bx + si;
949 break;
950 case 1:
951 modrm_ea += bx + di;
952 break;
953 case 2:
954 modrm_ea += bp + si;
955 break;
956 case 3:
957 modrm_ea += bp + di;
958 break;
959 case 4:
960 modrm_ea += si;
961 break;
962 case 5:
963 modrm_ea += di;
964 break;
965 case 6:
966 if (ctxt->modrm_mod != 0)
967 modrm_ea += bp;
968 break;
969 case 7:
970 modrm_ea += bx;
971 break;
972 }
973 if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 ||
974 (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0))
975 ctxt->modrm_seg = VCPU_SREG_SS;
976 modrm_ea = (u16)modrm_ea;
977 } else {
978 /* 32/64-bit ModR/M decode. */
979 if ((ctxt->modrm_rm & 7) == 4) {
980 sib = insn_fetch(u8, ctxt);
981 index_reg |= (sib >> 3) & 7;
982 base_reg |= sib & 7;
983 scale = sib >> 6;
984
985 if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0)
986 modrm_ea += insn_fetch(s32, ctxt);
987 else
988 modrm_ea += ctxt->regs[base_reg];
989 if (index_reg != 4)
990 modrm_ea += ctxt->regs[index_reg] << scale;
991 } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) {
992 if (ctxt->mode == X86EMUL_MODE_PROT64)
993 ctxt->rip_relative = 1;
994 } else
995 modrm_ea += ctxt->regs[ctxt->modrm_rm];
996 switch (ctxt->modrm_mod) {
997 case 0:
998 if (ctxt->modrm_rm == 5)
999 modrm_ea += insn_fetch(s32, ctxt);
1000 break;
1001 case 1:
1002 modrm_ea += insn_fetch(s8, ctxt);
1003 break;
1004 case 2:
1005 modrm_ea += insn_fetch(s32, ctxt);
1006 break;
1007 }
1008 }
1009 op->addr.mem.ea = modrm_ea;
1010 done:
1011 return rc;
1012 }
1013
1014 static int decode_abs(struct x86_emulate_ctxt *ctxt,
1015 struct operand *op)
1016 {
1017 int rc = X86EMUL_CONTINUE;
1018
1019 op->type = OP_MEM;
1020 switch (ctxt->ad_bytes) {
1021 case 2:
1022 op->addr.mem.ea = insn_fetch(u16, ctxt);
1023 break;
1024 case 4:
1025 op->addr.mem.ea = insn_fetch(u32, ctxt);
1026 break;
1027 case 8:
1028 op->addr.mem.ea = insn_fetch(u64, ctxt);
1029 break;
1030 }
1031 done:
1032 return rc;
1033 }
1034
1035 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt)
1036 {
1037 long sv = 0, mask;
1038
1039 if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) {
1040 mask = ~(ctxt->dst.bytes * 8 - 1);
1041
1042 if (ctxt->src.bytes == 2)
1043 sv = (s16)ctxt->src.val & (s16)mask;
1044 else if (ctxt->src.bytes == 4)
1045 sv = (s32)ctxt->src.val & (s32)mask;
1046
1047 ctxt->dst.addr.mem.ea += (sv >> 3);
1048 }
1049
1050 /* only subword offset */
1051 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
1052 }
1053
1054 static int read_emulated(struct x86_emulate_ctxt *ctxt,
1055 unsigned long addr, void *dest, unsigned size)
1056 {
1057 int rc;
1058 struct read_cache *mc = &ctxt->mem_read;
1059
1060 while (size) {
1061 int n = min(size, 8u);
1062 size -= n;
1063 if (mc->pos < mc->end)
1064 goto read_cached;
1065
1066 rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, n,
1067 &ctxt->exception);
1068 if (rc != X86EMUL_CONTINUE)
1069 return rc;
1070 mc->end += n;
1071
1072 read_cached:
1073 memcpy(dest, mc->data + mc->pos, n);
1074 mc->pos += n;
1075 dest += n;
1076 addr += n;
1077 }
1078 return X86EMUL_CONTINUE;
1079 }
1080
1081 static int segmented_read(struct x86_emulate_ctxt *ctxt,
1082 struct segmented_address addr,
1083 void *data,
1084 unsigned size)
1085 {
1086 int rc;
1087 ulong linear;
1088
1089 rc = linearize(ctxt, addr, size, false, &linear);
1090 if (rc != X86EMUL_CONTINUE)
1091 return rc;
1092 return read_emulated(ctxt, linear, data, size);
1093 }
1094
1095 static int segmented_write(struct x86_emulate_ctxt *ctxt,
1096 struct segmented_address addr,
1097 const void *data,
1098 unsigned size)
1099 {
1100 int rc;
1101 ulong linear;
1102
1103 rc = linearize(ctxt, addr, size, true, &linear);
1104 if (rc != X86EMUL_CONTINUE)
1105 return rc;
1106 return ctxt->ops->write_emulated(ctxt, linear, data, size,
1107 &ctxt->exception);
1108 }
1109
1110 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
1111 struct segmented_address addr,
1112 const void *orig_data, const void *data,
1113 unsigned size)
1114 {
1115 int rc;
1116 ulong linear;
1117
1118 rc = linearize(ctxt, addr, size, true, &linear);
1119 if (rc != X86EMUL_CONTINUE)
1120 return rc;
1121 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data,
1122 size, &ctxt->exception);
1123 }
1124
1125 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
1126 unsigned int size, unsigned short port,
1127 void *dest)
1128 {
1129 struct read_cache *rc = &ctxt->io_read;
1130
1131 if (rc->pos == rc->end) { /* refill pio read ahead */
1132 unsigned int in_page, n;
1133 unsigned int count = ctxt->rep_prefix ?
1134 address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) : 1;
1135 in_page = (ctxt->eflags & EFLG_DF) ?
1136 offset_in_page(ctxt->regs[VCPU_REGS_RDI]) :
1137 PAGE_SIZE - offset_in_page(ctxt->regs[VCPU_REGS_RDI]);
1138 n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size,
1139 count);
1140 if (n == 0)
1141 n = 1;
1142 rc->pos = rc->end = 0;
1143 if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n))
1144 return 0;
1145 rc->end = n * size;
1146 }
1147
1148 memcpy(dest, rc->data + rc->pos, size);
1149 rc->pos += size;
1150 return 1;
1151 }
1152
1153 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
1154 u16 selector, struct desc_ptr *dt)
1155 {
1156 struct x86_emulate_ops *ops = ctxt->ops;
1157
1158 if (selector & 1 << 2) {
1159 struct desc_struct desc;
1160 u16 sel;
1161
1162 memset (dt, 0, sizeof *dt);
1163 if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR))
1164 return;
1165
1166 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
1167 dt->address = get_desc_base(&desc);
1168 } else
1169 ops->get_gdt(ctxt, dt);
1170 }
1171
1172 /* allowed just for 8 bytes segments */
1173 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1174 u16 selector, struct desc_struct *desc)
1175 {
1176 struct desc_ptr dt;
1177 u16 index = selector >> 3;
1178 ulong addr;
1179
1180 get_descriptor_table_ptr(ctxt, selector, &dt);
1181
1182 if (dt.size < index * 8 + 7)
1183 return emulate_gp(ctxt, selector & 0xfffc);
1184
1185 addr = dt.address + index * 8;
1186 return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1187 &ctxt->exception);
1188 }
1189
1190 /* allowed just for 8 bytes segments */
1191 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1192 u16 selector, struct desc_struct *desc)
1193 {
1194 struct desc_ptr dt;
1195 u16 index = selector >> 3;
1196 ulong addr;
1197
1198 get_descriptor_table_ptr(ctxt, selector, &dt);
1199
1200 if (dt.size < index * 8 + 7)
1201 return emulate_gp(ctxt, selector & 0xfffc);
1202
1203 addr = dt.address + index * 8;
1204 return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,
1205 &ctxt->exception);
1206 }
1207
1208 /* Does not support long mode */
1209 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1210 u16 selector, int seg)
1211 {
1212 struct desc_struct seg_desc;
1213 u8 dpl, rpl, cpl;
1214 unsigned err_vec = GP_VECTOR;
1215 u32 err_code = 0;
1216 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
1217 int ret;
1218
1219 memset(&seg_desc, 0, sizeof seg_desc);
1220
1221 if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86)
1222 || ctxt->mode == X86EMUL_MODE_REAL) {
1223 /* set real mode segment descriptor */
1224 set_desc_base(&seg_desc, selector << 4);
1225 set_desc_limit(&seg_desc, 0xffff);
1226 seg_desc.type = 3;
1227 seg_desc.p = 1;
1228 seg_desc.s = 1;
1229 goto load;
1230 }
1231
1232 /* NULL selector is not valid for TR, CS and SS */
1233 if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR)
1234 && null_selector)
1235 goto exception;
1236
1237 /* TR should be in GDT only */
1238 if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
1239 goto exception;
1240
1241 if (null_selector) /* for NULL selector skip all following checks */
1242 goto load;
1243
1244 ret = read_segment_descriptor(ctxt, selector, &seg_desc);
1245 if (ret != X86EMUL_CONTINUE)
1246 return ret;
1247
1248 err_code = selector & 0xfffc;
1249 err_vec = GP_VECTOR;
1250
1251 /* can't load system descriptor into segment selecor */
1252 if (seg <= VCPU_SREG_GS && !seg_desc.s)
1253 goto exception;
1254
1255 if (!seg_desc.p) {
1256 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
1257 goto exception;
1258 }
1259
1260 rpl = selector & 3;
1261 dpl = seg_desc.dpl;
1262 cpl = ctxt->ops->cpl(ctxt);
1263
1264 switch (seg) {
1265 case VCPU_SREG_SS:
1266 /*
1267 * segment is not a writable data segment or segment
1268 * selector's RPL != CPL or segment selector's RPL != CPL
1269 */
1270 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
1271 goto exception;
1272 break;
1273 case VCPU_SREG_CS:
1274 if (!(seg_desc.type & 8))
1275 goto exception;
1276
1277 if (seg_desc.type & 4) {
1278 /* conforming */
1279 if (dpl > cpl)
1280 goto exception;
1281 } else {
1282 /* nonconforming */
1283 if (rpl > cpl || dpl != cpl)
1284 goto exception;
1285 }
1286 /* CS(RPL) <- CPL */
1287 selector = (selector & 0xfffc) | cpl;
1288 break;
1289 case VCPU_SREG_TR:
1290 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1291 goto exception;
1292 break;
1293 case VCPU_SREG_LDTR:
1294 if (seg_desc.s || seg_desc.type != 2)
1295 goto exception;
1296 break;
1297 default: /* DS, ES, FS, or GS */
1298 /*
1299 * segment is not a data or readable code segment or
1300 * ((segment is a data or nonconforming code segment)
1301 * and (both RPL and CPL > DPL))
1302 */
1303 if ((seg_desc.type & 0xa) == 0x8 ||
1304 (((seg_desc.type & 0xc) != 0xc) &&
1305 (rpl > dpl && cpl > dpl)))
1306 goto exception;
1307 break;
1308 }
1309
1310 if (seg_desc.s) {
1311 /* mark segment as accessed */
1312 seg_desc.type |= 1;
1313 ret = write_segment_descriptor(ctxt, selector, &seg_desc);
1314 if (ret != X86EMUL_CONTINUE)
1315 return ret;
1316 }
1317 load:
1318 ctxt->ops->set_segment(ctxt, selector, &seg_desc, 0, seg);
1319 return X86EMUL_CONTINUE;
1320 exception:
1321 emulate_exception(ctxt, err_vec, err_code, true);
1322 return X86EMUL_PROPAGATE_FAULT;
1323 }
1324
1325 static void write_register_operand(struct operand *op)
1326 {
1327 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
1328 switch (op->bytes) {
1329 case 1:
1330 *(u8 *)op->addr.reg = (u8)op->val;
1331 break;
1332 case 2:
1333 *(u16 *)op->addr.reg = (u16)op->val;
1334 break;
1335 case 4:
1336 *op->addr.reg = (u32)op->val;
1337 break; /* 64b: zero-extend */
1338 case 8:
1339 *op->addr.reg = op->val;
1340 break;
1341 }
1342 }
1343
1344 static int writeback(struct x86_emulate_ctxt *ctxt)
1345 {
1346 int rc;
1347
1348 switch (ctxt->dst.type) {
1349 case OP_REG:
1350 write_register_operand(&ctxt->dst);
1351 break;
1352 case OP_MEM:
1353 if (ctxt->lock_prefix)
1354 rc = segmented_cmpxchg(ctxt,
1355 ctxt->dst.addr.mem,
1356 &ctxt->dst.orig_val,
1357 &ctxt->dst.val,
1358 ctxt->dst.bytes);
1359 else
1360 rc = segmented_write(ctxt,
1361 ctxt->dst.addr.mem,
1362 &ctxt->dst.val,
1363 ctxt->dst.bytes);
1364 if (rc != X86EMUL_CONTINUE)
1365 return rc;
1366 break;
1367 case OP_XMM:
1368 write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm);
1369 break;
1370 case OP_NONE:
1371 /* no writeback */
1372 break;
1373 default:
1374 break;
1375 }
1376 return X86EMUL_CONTINUE;
1377 }
1378
1379 static int em_push(struct x86_emulate_ctxt *ctxt)
1380 {
1381 struct segmented_address addr;
1382
1383 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], -ctxt->op_bytes);
1384 addr.ea = register_address(ctxt, ctxt->regs[VCPU_REGS_RSP]);
1385 addr.seg = VCPU_SREG_SS;
1386
1387 /* Disable writeback. */
1388 ctxt->dst.type = OP_NONE;
1389 return segmented_write(ctxt, addr, &ctxt->src.val, ctxt->op_bytes);
1390 }
1391
1392 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1393 void *dest, int len)
1394 {
1395 int rc;
1396 struct segmented_address addr;
1397
1398 addr.ea = register_address(ctxt, ctxt->regs[VCPU_REGS_RSP]);
1399 addr.seg = VCPU_SREG_SS;
1400 rc = segmented_read(ctxt, addr, dest, len);
1401 if (rc != X86EMUL_CONTINUE)
1402 return rc;
1403
1404 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], len);
1405 return rc;
1406 }
1407
1408 static int em_pop(struct x86_emulate_ctxt *ctxt)
1409 {
1410 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1411 }
1412
1413 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1414 void *dest, int len)
1415 {
1416 int rc;
1417 unsigned long val, change_mask;
1418 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1419 int cpl = ctxt->ops->cpl(ctxt);
1420
1421 rc = emulate_pop(ctxt, &val, len);
1422 if (rc != X86EMUL_CONTINUE)
1423 return rc;
1424
1425 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
1426 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID;
1427
1428 switch(ctxt->mode) {
1429 case X86EMUL_MODE_PROT64:
1430 case X86EMUL_MODE_PROT32:
1431 case X86EMUL_MODE_PROT16:
1432 if (cpl == 0)
1433 change_mask |= EFLG_IOPL;
1434 if (cpl <= iopl)
1435 change_mask |= EFLG_IF;
1436 break;
1437 case X86EMUL_MODE_VM86:
1438 if (iopl < 3)
1439 return emulate_gp(ctxt, 0);
1440 change_mask |= EFLG_IF;
1441 break;
1442 default: /* real mode */
1443 change_mask |= (EFLG_IOPL | EFLG_IF);
1444 break;
1445 }
1446
1447 *(unsigned long *)dest =
1448 (ctxt->eflags & ~change_mask) | (val & change_mask);
1449
1450 return rc;
1451 }
1452
1453 static int em_popf(struct x86_emulate_ctxt *ctxt)
1454 {
1455 ctxt->dst.type = OP_REG;
1456 ctxt->dst.addr.reg = &ctxt->eflags;
1457 ctxt->dst.bytes = ctxt->op_bytes;
1458 return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1459 }
1460
1461 static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
1462 {
1463 int seg = ctxt->src2.val;
1464
1465 ctxt->src.val = get_segment_selector(ctxt, seg);
1466
1467 return em_push(ctxt);
1468 }
1469
1470 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt)
1471 {
1472 int seg = ctxt->src2.val;
1473 unsigned long selector;
1474 int rc;
1475
1476 rc = emulate_pop(ctxt, &selector, ctxt->op_bytes);
1477 if (rc != X86EMUL_CONTINUE)
1478 return rc;
1479
1480 rc = load_segment_descriptor(ctxt, (u16)selector, seg);
1481 return rc;
1482 }
1483
1484 static int em_pusha(struct x86_emulate_ctxt *ctxt)
1485 {
1486 unsigned long old_esp = ctxt->regs[VCPU_REGS_RSP];
1487 int rc = X86EMUL_CONTINUE;
1488 int reg = VCPU_REGS_RAX;
1489
1490 while (reg <= VCPU_REGS_RDI) {
1491 (reg == VCPU_REGS_RSP) ?
1492 (ctxt->src.val = old_esp) : (ctxt->src.val = ctxt->regs[reg]);
1493
1494 rc = em_push(ctxt);
1495 if (rc != X86EMUL_CONTINUE)
1496 return rc;
1497
1498 ++reg;
1499 }
1500
1501 return rc;
1502 }
1503
1504 static int em_pushf(struct x86_emulate_ctxt *ctxt)
1505 {
1506 ctxt->src.val = (unsigned long)ctxt->eflags;
1507 return em_push(ctxt);
1508 }
1509
1510 static int em_popa(struct x86_emulate_ctxt *ctxt)
1511 {
1512 int rc = X86EMUL_CONTINUE;
1513 int reg = VCPU_REGS_RDI;
1514
1515 while (reg >= VCPU_REGS_RAX) {
1516 if (reg == VCPU_REGS_RSP) {
1517 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP],
1518 ctxt->op_bytes);
1519 --reg;
1520 }
1521
1522 rc = emulate_pop(ctxt, &ctxt->regs[reg], ctxt->op_bytes);
1523 if (rc != X86EMUL_CONTINUE)
1524 break;
1525 --reg;
1526 }
1527 return rc;
1528 }
1529
1530 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1531 {
1532 struct x86_emulate_ops *ops = ctxt->ops;
1533 int rc;
1534 struct desc_ptr dt;
1535 gva_t cs_addr;
1536 gva_t eip_addr;
1537 u16 cs, eip;
1538
1539 /* TODO: Add limit checks */
1540 ctxt->src.val = ctxt->eflags;
1541 rc = em_push(ctxt);
1542 if (rc != X86EMUL_CONTINUE)
1543 return rc;
1544
1545 ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC);
1546
1547 ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS);
1548 rc = em_push(ctxt);
1549 if (rc != X86EMUL_CONTINUE)
1550 return rc;
1551
1552 ctxt->src.val = ctxt->_eip;
1553 rc = em_push(ctxt);
1554 if (rc != X86EMUL_CONTINUE)
1555 return rc;
1556
1557 ops->get_idt(ctxt, &dt);
1558
1559 eip_addr = dt.address + (irq << 2);
1560 cs_addr = dt.address + (irq << 2) + 2;
1561
1562 rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);
1563 if (rc != X86EMUL_CONTINUE)
1564 return rc;
1565
1566 rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);
1567 if (rc != X86EMUL_CONTINUE)
1568 return rc;
1569
1570 rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS);
1571 if (rc != X86EMUL_CONTINUE)
1572 return rc;
1573
1574 ctxt->_eip = eip;
1575
1576 return rc;
1577 }
1578
1579 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq)
1580 {
1581 switch(ctxt->mode) {
1582 case X86EMUL_MODE_REAL:
1583 return emulate_int_real(ctxt, irq);
1584 case X86EMUL_MODE_VM86:
1585 case X86EMUL_MODE_PROT16:
1586 case X86EMUL_MODE_PROT32:
1587 case X86EMUL_MODE_PROT64:
1588 default:
1589 /* Protected mode interrupts unimplemented yet */
1590 return X86EMUL_UNHANDLEABLE;
1591 }
1592 }
1593
1594 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
1595 {
1596 int rc = X86EMUL_CONTINUE;
1597 unsigned long temp_eip = 0;
1598 unsigned long temp_eflags = 0;
1599 unsigned long cs = 0;
1600 unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF |
1601 EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF |
1602 EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */
1603 unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP;
1604
1605 /* TODO: Add stack limit check */
1606
1607 rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes);
1608
1609 if (rc != X86EMUL_CONTINUE)
1610 return rc;
1611
1612 if (temp_eip & ~0xffff)
1613 return emulate_gp(ctxt, 0);
1614
1615 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
1616
1617 if (rc != X86EMUL_CONTINUE)
1618 return rc;
1619
1620 rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes);
1621
1622 if (rc != X86EMUL_CONTINUE)
1623 return rc;
1624
1625 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
1626
1627 if (rc != X86EMUL_CONTINUE)
1628 return rc;
1629
1630 ctxt->_eip = temp_eip;
1631
1632
1633 if (ctxt->op_bytes == 4)
1634 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
1635 else if (ctxt->op_bytes == 2) {
1636 ctxt->eflags &= ~0xffff;
1637 ctxt->eflags |= temp_eflags;
1638 }
1639
1640 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
1641 ctxt->eflags |= EFLG_RESERVED_ONE_MASK;
1642
1643 return rc;
1644 }
1645
1646 static int em_iret(struct x86_emulate_ctxt *ctxt)
1647 {
1648 switch(ctxt->mode) {
1649 case X86EMUL_MODE_REAL:
1650 return emulate_iret_real(ctxt);
1651 case X86EMUL_MODE_VM86:
1652 case X86EMUL_MODE_PROT16:
1653 case X86EMUL_MODE_PROT32:
1654 case X86EMUL_MODE_PROT64:
1655 default:
1656 /* iret from protected mode unimplemented yet */
1657 return X86EMUL_UNHANDLEABLE;
1658 }
1659 }
1660
1661 static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
1662 {
1663 int rc;
1664 unsigned short sel;
1665
1666 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
1667
1668 rc = load_segment_descriptor(ctxt, sel, VCPU_SREG_CS);
1669 if (rc != X86EMUL_CONTINUE)
1670 return rc;
1671
1672 ctxt->_eip = 0;
1673 memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
1674 return X86EMUL_CONTINUE;
1675 }
1676
1677 static int em_grp1a(struct x86_emulate_ctxt *ctxt)
1678 {
1679 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->dst.bytes);
1680 }
1681
1682 static int em_grp2(struct x86_emulate_ctxt *ctxt)
1683 {
1684 switch (ctxt->modrm_reg) {
1685 case 0: /* rol */
1686 emulate_2op_SrcB(ctxt, "rol");
1687 break;
1688 case 1: /* ror */
1689 emulate_2op_SrcB(ctxt, "ror");
1690 break;
1691 case 2: /* rcl */
1692 emulate_2op_SrcB(ctxt, "rcl");
1693 break;
1694 case 3: /* rcr */
1695 emulate_2op_SrcB(ctxt, "rcr");
1696 break;
1697 case 4: /* sal/shl */
1698 case 6: /* sal/shl */
1699 emulate_2op_SrcB(ctxt, "sal");
1700 break;
1701 case 5: /* shr */
1702 emulate_2op_SrcB(ctxt, "shr");
1703 break;
1704 case 7: /* sar */
1705 emulate_2op_SrcB(ctxt, "sar");
1706 break;
1707 }
1708 return X86EMUL_CONTINUE;
1709 }
1710
1711 static int em_not(struct x86_emulate_ctxt *ctxt)
1712 {
1713 ctxt->dst.val = ~ctxt->dst.val;
1714 return X86EMUL_CONTINUE;
1715 }
1716
1717 static int em_neg(struct x86_emulate_ctxt *ctxt)
1718 {
1719 emulate_1op(ctxt, "neg");
1720 return X86EMUL_CONTINUE;
1721 }
1722
1723 static int em_mul_ex(struct x86_emulate_ctxt *ctxt)
1724 {
1725 u8 ex = 0;
1726
1727 emulate_1op_rax_rdx(ctxt, "mul", ex);
1728 return X86EMUL_CONTINUE;
1729 }
1730
1731 static int em_imul_ex(struct x86_emulate_ctxt *ctxt)
1732 {
1733 u8 ex = 0;
1734
1735 emulate_1op_rax_rdx(ctxt, "imul", ex);
1736 return X86EMUL_CONTINUE;
1737 }
1738
1739 static int em_div_ex(struct x86_emulate_ctxt *ctxt)
1740 {
1741 u8 de = 0;
1742
1743 emulate_1op_rax_rdx(ctxt, "div", de);
1744 if (de)
1745 return emulate_de(ctxt);
1746 return X86EMUL_CONTINUE;
1747 }
1748
1749 static int em_idiv_ex(struct x86_emulate_ctxt *ctxt)
1750 {
1751 u8 de = 0;
1752
1753 emulate_1op_rax_rdx(ctxt, "idiv", de);
1754 if (de)
1755 return emulate_de(ctxt);
1756 return X86EMUL_CONTINUE;
1757 }
1758
1759 static int em_grp45(struct x86_emulate_ctxt *ctxt)
1760 {
1761 int rc = X86EMUL_CONTINUE;
1762
1763 switch (ctxt->modrm_reg) {
1764 case 0: /* inc */
1765 emulate_1op(ctxt, "inc");
1766 break;
1767 case 1: /* dec */
1768 emulate_1op(ctxt, "dec");
1769 break;
1770 case 2: /* call near abs */ {
1771 long int old_eip;
1772 old_eip = ctxt->_eip;
1773 ctxt->_eip = ctxt->src.val;
1774 ctxt->src.val = old_eip;
1775 rc = em_push(ctxt);
1776 break;
1777 }
1778 case 4: /* jmp abs */
1779 ctxt->_eip = ctxt->src.val;
1780 break;
1781 case 5: /* jmp far */
1782 rc = em_jmp_far(ctxt);
1783 break;
1784 case 6: /* push */
1785 rc = em_push(ctxt);
1786 break;
1787 }
1788 return rc;
1789 }
1790
1791 static int em_grp9(struct x86_emulate_ctxt *ctxt)
1792 {
1793 u64 old = ctxt->dst.orig_val64;
1794
1795 if (((u32) (old >> 0) != (u32) ctxt->regs[VCPU_REGS_RAX]) ||
1796 ((u32) (old >> 32) != (u32) ctxt->regs[VCPU_REGS_RDX])) {
1797 ctxt->regs[VCPU_REGS_RAX] = (u32) (old >> 0);
1798 ctxt->regs[VCPU_REGS_RDX] = (u32) (old >> 32);
1799 ctxt->eflags &= ~EFLG_ZF;
1800 } else {
1801 ctxt->dst.val64 = ((u64)ctxt->regs[VCPU_REGS_RCX] << 32) |
1802 (u32) ctxt->regs[VCPU_REGS_RBX];
1803
1804 ctxt->eflags |= EFLG_ZF;
1805 }
1806 return X86EMUL_CONTINUE;
1807 }
1808
1809 static int em_ret(struct x86_emulate_ctxt *ctxt)
1810 {
1811 ctxt->dst.type = OP_REG;
1812 ctxt->dst.addr.reg = &ctxt->_eip;
1813 ctxt->dst.bytes = ctxt->op_bytes;
1814 return em_pop(ctxt);
1815 }
1816
1817 static int em_ret_far(struct x86_emulate_ctxt *ctxt)
1818 {
1819 int rc;
1820 unsigned long cs;
1821
1822 rc = emulate_pop(ctxt, &ctxt->_eip, ctxt->op_bytes);
1823 if (rc != X86EMUL_CONTINUE)
1824 return rc;
1825 if (ctxt->op_bytes == 4)
1826 ctxt->_eip = (u32)ctxt->_eip;
1827 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
1828 if (rc != X86EMUL_CONTINUE)
1829 return rc;
1830 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
1831 return rc;
1832 }
1833
1834 static int em_lseg(struct x86_emulate_ctxt *ctxt)
1835 {
1836 int seg = ctxt->src2.val;
1837 unsigned short sel;
1838 int rc;
1839
1840 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
1841
1842 rc = load_segment_descriptor(ctxt, sel, seg);
1843 if (rc != X86EMUL_CONTINUE)
1844 return rc;
1845
1846 ctxt->dst.val = ctxt->src.val;
1847 return rc;
1848 }
1849
1850 static void
1851 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
1852 struct desc_struct *cs, struct desc_struct *ss)
1853 {
1854 u16 selector;
1855
1856 memset(cs, 0, sizeof(struct desc_struct));
1857 ctxt->ops->get_segment(ctxt, &selector, cs, NULL, VCPU_SREG_CS);
1858 memset(ss, 0, sizeof(struct desc_struct));
1859
1860 cs->l = 0; /* will be adjusted later */
1861 set_desc_base(cs, 0); /* flat segment */
1862 cs->g = 1; /* 4kb granularity */
1863 set_desc_limit(cs, 0xfffff); /* 4GB limit */
1864 cs->type = 0x0b; /* Read, Execute, Accessed */
1865 cs->s = 1;
1866 cs->dpl = 0; /* will be adjusted later */
1867 cs->p = 1;
1868 cs->d = 1;
1869
1870 set_desc_base(ss, 0); /* flat segment */
1871 set_desc_limit(ss, 0xfffff); /* 4GB limit */
1872 ss->g = 1; /* 4kb granularity */
1873 ss->s = 1;
1874 ss->type = 0x03; /* Read/Write, Accessed */
1875 ss->d = 1; /* 32bit stack segment */
1876 ss->dpl = 0;
1877 ss->p = 1;
1878 }
1879
1880 static int em_syscall(struct x86_emulate_ctxt *ctxt)
1881 {
1882 struct x86_emulate_ops *ops = ctxt->ops;
1883 struct desc_struct cs, ss;
1884 u64 msr_data;
1885 u16 cs_sel, ss_sel;
1886 u64 efer = 0;
1887
1888 /* syscall is not available in real mode */
1889 if (ctxt->mode == X86EMUL_MODE_REAL ||
1890 ctxt->mode == X86EMUL_MODE_VM86)
1891 return emulate_ud(ctxt);
1892
1893 ops->get_msr(ctxt, MSR_EFER, &efer);
1894 setup_syscalls_segments(ctxt, &cs, &ss);
1895
1896 ops->get_msr(ctxt, MSR_STAR, &msr_data);
1897 msr_data >>= 32;
1898 cs_sel = (u16)(msr_data & 0xfffc);
1899 ss_sel = (u16)(msr_data + 8);
1900
1901 if (efer & EFER_LMA) {
1902 cs.d = 0;
1903 cs.l = 1;
1904 }
1905 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
1906 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
1907
1908 ctxt->regs[VCPU_REGS_RCX] = ctxt->_eip;
1909 if (efer & EFER_LMA) {
1910 #ifdef CONFIG_X86_64
1911 ctxt->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF;
1912
1913 ops->get_msr(ctxt,
1914 ctxt->mode == X86EMUL_MODE_PROT64 ?
1915 MSR_LSTAR : MSR_CSTAR, &msr_data);
1916 ctxt->_eip = msr_data;
1917
1918 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data);
1919 ctxt->eflags &= ~(msr_data | EFLG_RF);
1920 #endif
1921 } else {
1922 /* legacy mode */
1923 ops->get_msr(ctxt, MSR_STAR, &msr_data);
1924 ctxt->_eip = (u32)msr_data;
1925
1926 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1927 }
1928
1929 return X86EMUL_CONTINUE;
1930 }
1931
1932 static int em_sysenter(struct x86_emulate_ctxt *ctxt)
1933 {
1934 struct x86_emulate_ops *ops = ctxt->ops;
1935 struct desc_struct cs, ss;
1936 u64 msr_data;
1937 u16 cs_sel, ss_sel;
1938 u64 efer = 0;
1939
1940 ops->get_msr(ctxt, MSR_EFER, &efer);
1941 /* inject #GP if in real mode */
1942 if (ctxt->mode == X86EMUL_MODE_REAL)
1943 return emulate_gp(ctxt, 0);
1944
1945 /* XXX sysenter/sysexit have not been tested in 64bit mode.
1946 * Therefore, we inject an #UD.
1947 */
1948 if (ctxt->mode == X86EMUL_MODE_PROT64)
1949 return emulate_ud(ctxt);
1950
1951 setup_syscalls_segments(ctxt, &cs, &ss);
1952
1953 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
1954 switch (ctxt->mode) {
1955 case X86EMUL_MODE_PROT32:
1956 if ((msr_data & 0xfffc) == 0x0)
1957 return emulate_gp(ctxt, 0);
1958 break;
1959 case X86EMUL_MODE_PROT64:
1960 if (msr_data == 0x0)
1961 return emulate_gp(ctxt, 0);
1962 break;
1963 }
1964
1965 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1966 cs_sel = (u16)msr_data;
1967 cs_sel &= ~SELECTOR_RPL_MASK;
1968 ss_sel = cs_sel + 8;
1969 ss_sel &= ~SELECTOR_RPL_MASK;
1970 if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) {
1971 cs.d = 0;
1972 cs.l = 1;
1973 }
1974
1975 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
1976 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
1977
1978 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
1979 ctxt->_eip = msr_data;
1980
1981 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
1982 ctxt->regs[VCPU_REGS_RSP] = msr_data;
1983
1984 return X86EMUL_CONTINUE;
1985 }
1986
1987 static int em_sysexit(struct x86_emulate_ctxt *ctxt)
1988 {
1989 struct x86_emulate_ops *ops = ctxt->ops;
1990 struct desc_struct cs, ss;
1991 u64 msr_data;
1992 int usermode;
1993 u16 cs_sel = 0, ss_sel = 0;
1994
1995 /* inject #GP if in real mode or Virtual 8086 mode */
1996 if (ctxt->mode == X86EMUL_MODE_REAL ||
1997 ctxt->mode == X86EMUL_MODE_VM86)
1998 return emulate_gp(ctxt, 0);
1999
2000 setup_syscalls_segments(ctxt, &cs, &ss);
2001
2002 if ((ctxt->rex_prefix & 0x8) != 0x0)
2003 usermode = X86EMUL_MODE_PROT64;
2004 else
2005 usermode = X86EMUL_MODE_PROT32;
2006
2007 cs.dpl = 3;
2008 ss.dpl = 3;
2009 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2010 switch (usermode) {
2011 case X86EMUL_MODE_PROT32:
2012 cs_sel = (u16)(msr_data + 16);
2013 if ((msr_data & 0xfffc) == 0x0)
2014 return emulate_gp(ctxt, 0);
2015 ss_sel = (u16)(msr_data + 24);
2016 break;
2017 case X86EMUL_MODE_PROT64:
2018 cs_sel = (u16)(msr_data + 32);
2019 if (msr_data == 0x0)
2020 return emulate_gp(ctxt, 0);
2021 ss_sel = cs_sel + 8;
2022 cs.d = 0;
2023 cs.l = 1;
2024 break;
2025 }
2026 cs_sel |= SELECTOR_RPL_MASK;
2027 ss_sel |= SELECTOR_RPL_MASK;
2028
2029 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2030 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2031
2032 ctxt->_eip = ctxt->regs[VCPU_REGS_RDX];
2033 ctxt->regs[VCPU_REGS_RSP] = ctxt->regs[VCPU_REGS_RCX];
2034
2035 return X86EMUL_CONTINUE;
2036 }
2037
2038 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt)
2039 {
2040 int iopl;
2041 if (ctxt->mode == X86EMUL_MODE_REAL)
2042 return false;
2043 if (ctxt->mode == X86EMUL_MODE_VM86)
2044 return true;
2045 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
2046 return ctxt->ops->cpl(ctxt) > iopl;
2047 }
2048
2049 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
2050 u16 port, u16 len)
2051 {
2052 struct x86_emulate_ops *ops = ctxt->ops;
2053 struct desc_struct tr_seg;
2054 u32 base3;
2055 int r;
2056 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7;
2057 unsigned mask = (1 << len) - 1;
2058 unsigned long base;
2059
2060 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR);
2061 if (!tr_seg.p)
2062 return false;
2063 if (desc_limit_scaled(&tr_seg) < 103)
2064 return false;
2065 base = get_desc_base(&tr_seg);
2066 #ifdef CONFIG_X86_64
2067 base |= ((u64)base3) << 32;
2068 #endif
2069 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL);
2070 if (r != X86EMUL_CONTINUE)
2071 return false;
2072 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
2073 return false;
2074 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL);
2075 if (r != X86EMUL_CONTINUE)
2076 return false;
2077 if ((perm >> bit_idx) & mask)
2078 return false;
2079 return true;
2080 }
2081
2082 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
2083 u16 port, u16 len)
2084 {
2085 if (ctxt->perm_ok)
2086 return true;
2087
2088 if (emulator_bad_iopl(ctxt))
2089 if (!emulator_io_port_access_allowed(ctxt, port, len))
2090 return false;
2091
2092 ctxt->perm_ok = true;
2093
2094 return true;
2095 }
2096
2097 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
2098 struct tss_segment_16 *tss)
2099 {
2100 tss->ip = ctxt->_eip;
2101 tss->flag = ctxt->eflags;
2102 tss->ax = ctxt->regs[VCPU_REGS_RAX];
2103 tss->cx = ctxt->regs[VCPU_REGS_RCX];
2104 tss->dx = ctxt->regs[VCPU_REGS_RDX];
2105 tss->bx = ctxt->regs[VCPU_REGS_RBX];
2106 tss->sp = ctxt->regs[VCPU_REGS_RSP];
2107 tss->bp = ctxt->regs[VCPU_REGS_RBP];
2108 tss->si = ctxt->regs[VCPU_REGS_RSI];
2109 tss->di = ctxt->regs[VCPU_REGS_RDI];
2110
2111 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2112 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2113 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2114 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2115 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2116 }
2117
2118 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
2119 struct tss_segment_16 *tss)
2120 {
2121 int ret;
2122
2123 ctxt->_eip = tss->ip;
2124 ctxt->eflags = tss->flag | 2;
2125 ctxt->regs[VCPU_REGS_RAX] = tss->ax;
2126 ctxt->regs[VCPU_REGS_RCX] = tss->cx;
2127 ctxt->regs[VCPU_REGS_RDX] = tss->dx;
2128 ctxt->regs[VCPU_REGS_RBX] = tss->bx;
2129 ctxt->regs[VCPU_REGS_RSP] = tss->sp;
2130 ctxt->regs[VCPU_REGS_RBP] = tss->bp;
2131 ctxt->regs[VCPU_REGS_RSI] = tss->si;
2132 ctxt->regs[VCPU_REGS_RDI] = tss->di;
2133
2134 /*
2135 * SDM says that segment selectors are loaded before segment
2136 * descriptors
2137 */
2138 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR);
2139 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2140 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2141 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2142 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2143
2144 /*
2145 * Now load segment descriptors. If fault happenes at this stage
2146 * it is handled in a context of new task
2147 */
2148 ret = load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR);
2149 if (ret != X86EMUL_CONTINUE)
2150 return ret;
2151 ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
2152 if (ret != X86EMUL_CONTINUE)
2153 return ret;
2154 ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
2155 if (ret != X86EMUL_CONTINUE)
2156 return ret;
2157 ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
2158 if (ret != X86EMUL_CONTINUE)
2159 return ret;
2160 ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
2161 if (ret != X86EMUL_CONTINUE)
2162 return ret;
2163
2164 return X86EMUL_CONTINUE;
2165 }
2166
2167 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
2168 u16 tss_selector, u16 old_tss_sel,
2169 ulong old_tss_base, struct desc_struct *new_desc)
2170 {
2171 struct x86_emulate_ops *ops = ctxt->ops;
2172 struct tss_segment_16 tss_seg;
2173 int ret;
2174 u32 new_tss_base = get_desc_base(new_desc);
2175
2176 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2177 &ctxt->exception);
2178 if (ret != X86EMUL_CONTINUE)
2179 /* FIXME: need to provide precise fault address */
2180 return ret;
2181
2182 save_state_to_tss16(ctxt, &tss_seg);
2183
2184 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2185 &ctxt->exception);
2186 if (ret != X86EMUL_CONTINUE)
2187 /* FIXME: need to provide precise fault address */
2188 return ret;
2189
2190 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2191 &ctxt->exception);
2192 if (ret != X86EMUL_CONTINUE)
2193 /* FIXME: need to provide precise fault address */
2194 return ret;
2195
2196 if (old_tss_sel != 0xffff) {
2197 tss_seg.prev_task_link = old_tss_sel;
2198
2199 ret = ops->write_std(ctxt, new_tss_base,
2200 &tss_seg.prev_task_link,
2201 sizeof tss_seg.prev_task_link,
2202 &ctxt->exception);
2203 if (ret != X86EMUL_CONTINUE)
2204 /* FIXME: need to provide precise fault address */
2205 return ret;
2206 }
2207
2208 return load_state_from_tss16(ctxt, &tss_seg);
2209 }
2210
2211 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
2212 struct tss_segment_32 *tss)
2213 {
2214 tss->cr3 = ctxt->ops->get_cr(ctxt, 3);
2215 tss->eip = ctxt->_eip;
2216 tss->eflags = ctxt->eflags;
2217 tss->eax = ctxt->regs[VCPU_REGS_RAX];
2218 tss->ecx = ctxt->regs[VCPU_REGS_RCX];
2219 tss->edx = ctxt->regs[VCPU_REGS_RDX];
2220 tss->ebx = ctxt->regs[VCPU_REGS_RBX];
2221 tss->esp = ctxt->regs[VCPU_REGS_RSP];
2222 tss->ebp = ctxt->regs[VCPU_REGS_RBP];
2223 tss->esi = ctxt->regs[VCPU_REGS_RSI];
2224 tss->edi = ctxt->regs[VCPU_REGS_RDI];
2225
2226 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2227 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2228 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2229 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2230 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS);
2231 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS);
2232 tss->ldt_selector = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2233 }
2234
2235 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
2236 struct tss_segment_32 *tss)
2237 {
2238 int ret;
2239
2240 if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
2241 return emulate_gp(ctxt, 0);
2242 ctxt->_eip = tss->eip;
2243 ctxt->eflags = tss->eflags | 2;
2244 ctxt->regs[VCPU_REGS_RAX] = tss->eax;
2245 ctxt->regs[VCPU_REGS_RCX] = tss->ecx;
2246 ctxt->regs[VCPU_REGS_RDX] = tss->edx;
2247 ctxt->regs[VCPU_REGS_RBX] = tss->ebx;
2248 ctxt->regs[VCPU_REGS_RSP] = tss->esp;
2249 ctxt->regs[VCPU_REGS_RBP] = tss->ebp;
2250 ctxt->regs[VCPU_REGS_RSI] = tss->esi;
2251 ctxt->regs[VCPU_REGS_RDI] = tss->edi;
2252
2253 /*
2254 * SDM says that segment selectors are loaded before segment
2255 * descriptors
2256 */
2257 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
2258 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2259 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2260 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2261 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2262 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS);
2263 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
2264
2265 /*
2266 * Now load segment descriptors. If fault happenes at this stage
2267 * it is handled in a context of new task
2268 */
2269 ret = load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
2270 if (ret != X86EMUL_CONTINUE)
2271 return ret;
2272 ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
2273 if (ret != X86EMUL_CONTINUE)
2274 return ret;
2275 ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
2276 if (ret != X86EMUL_CONTINUE)
2277 return ret;
2278 ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
2279 if (ret != X86EMUL_CONTINUE)
2280 return ret;
2281 ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
2282 if (ret != X86EMUL_CONTINUE)
2283 return ret;
2284 ret = load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS);
2285 if (ret != X86EMUL_CONTINUE)
2286 return ret;
2287 ret = load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS);
2288 if (ret != X86EMUL_CONTINUE)
2289 return ret;
2290
2291 return X86EMUL_CONTINUE;
2292 }
2293
2294 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
2295 u16 tss_selector, u16 old_tss_sel,
2296 ulong old_tss_base, struct desc_struct *new_desc)
2297 {
2298 struct x86_emulate_ops *ops = ctxt->ops;
2299 struct tss_segment_32 tss_seg;
2300 int ret;
2301 u32 new_tss_base = get_desc_base(new_desc);
2302
2303 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2304 &ctxt->exception);
2305 if (ret != X86EMUL_CONTINUE)
2306 /* FIXME: need to provide precise fault address */
2307 return ret;
2308
2309 save_state_to_tss32(ctxt, &tss_seg);
2310
2311 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2312 &ctxt->exception);
2313 if (ret != X86EMUL_CONTINUE)
2314 /* FIXME: need to provide precise fault address */
2315 return ret;
2316
2317 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2318 &ctxt->exception);
2319 if (ret != X86EMUL_CONTINUE)
2320 /* FIXME: need to provide precise fault address */
2321 return ret;
2322
2323 if (old_tss_sel != 0xffff) {
2324 tss_seg.prev_task_link = old_tss_sel;
2325
2326 ret = ops->write_std(ctxt, new_tss_base,
2327 &tss_seg.prev_task_link,
2328 sizeof tss_seg.prev_task_link,
2329 &ctxt->exception);
2330 if (ret != X86EMUL_CONTINUE)
2331 /* FIXME: need to provide precise fault address */
2332 return ret;
2333 }
2334
2335 return load_state_from_tss32(ctxt, &tss_seg);
2336 }
2337
2338 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
2339 u16 tss_selector, int reason,
2340 bool has_error_code, u32 error_code)
2341 {
2342 struct x86_emulate_ops *ops = ctxt->ops;
2343 struct desc_struct curr_tss_desc, next_tss_desc;
2344 int ret;
2345 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR);
2346 ulong old_tss_base =
2347 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR);
2348 u32 desc_limit;
2349
2350 /* FIXME: old_tss_base == ~0 ? */
2351
2352 ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
2353 if (ret != X86EMUL_CONTINUE)
2354 return ret;
2355 ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
2356 if (ret != X86EMUL_CONTINUE)
2357 return ret;
2358
2359 /* FIXME: check that next_tss_desc is tss */
2360
2361 if (reason != TASK_SWITCH_IRET) {
2362 if ((tss_selector & 3) > next_tss_desc.dpl ||
2363 ops->cpl(ctxt) > next_tss_desc.dpl)
2364 return emulate_gp(ctxt, 0);
2365 }
2366
2367 desc_limit = desc_limit_scaled(&next_tss_desc);
2368 if (!next_tss_desc.p ||
2369 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
2370 desc_limit < 0x2b)) {
2371 emulate_ts(ctxt, tss_selector & 0xfffc);
2372 return X86EMUL_PROPAGATE_FAULT;
2373 }
2374
2375 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
2376 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
2377 write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
2378 }
2379
2380 if (reason == TASK_SWITCH_IRET)
2381 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
2382
2383 /* set back link to prev task only if NT bit is set in eflags
2384 note that old_tss_sel is not used afetr this point */
2385 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
2386 old_tss_sel = 0xffff;
2387
2388 if (next_tss_desc.type & 8)
2389 ret = task_switch_32(ctxt, tss_selector, old_tss_sel,
2390 old_tss_base, &next_tss_desc);
2391 else
2392 ret = task_switch_16(ctxt, tss_selector, old_tss_sel,
2393 old_tss_base, &next_tss_desc);
2394 if (ret != X86EMUL_CONTINUE)
2395 return ret;
2396
2397 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
2398 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
2399
2400 if (reason != TASK_SWITCH_IRET) {
2401 next_tss_desc.type |= (1 << 1); /* set busy flag */
2402 write_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
2403 }
2404
2405 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS);
2406 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR);
2407
2408 if (has_error_code) {
2409 ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
2410 ctxt->lock_prefix = 0;
2411 ctxt->src.val = (unsigned long) error_code;
2412 ret = em_push(ctxt);
2413 }
2414
2415 return ret;
2416 }
2417
2418 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
2419 u16 tss_selector, int reason,
2420 bool has_error_code, u32 error_code)
2421 {
2422 int rc;
2423
2424 ctxt->_eip = ctxt->eip;
2425 ctxt->dst.type = OP_NONE;
2426
2427 rc = emulator_do_task_switch(ctxt, tss_selector, reason,
2428 has_error_code, error_code);
2429
2430 if (rc == X86EMUL_CONTINUE)
2431 ctxt->eip = ctxt->_eip;
2432
2433 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
2434 }
2435
2436 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned seg,
2437 int reg, struct operand *op)
2438 {
2439 int df = (ctxt->eflags & EFLG_DF) ? -1 : 1;
2440
2441 register_address_increment(ctxt, &ctxt->regs[reg], df * op->bytes);
2442 op->addr.mem.ea = register_address(ctxt, ctxt->regs[reg]);
2443 op->addr.mem.seg = seg;
2444 }
2445
2446 static int em_das(struct x86_emulate_ctxt *ctxt)
2447 {
2448 u8 al, old_al;
2449 bool af, cf, old_cf;
2450
2451 cf = ctxt->eflags & X86_EFLAGS_CF;
2452 al = ctxt->dst.val;
2453
2454 old_al = al;
2455 old_cf = cf;
2456 cf = false;
2457 af = ctxt->eflags & X86_EFLAGS_AF;
2458 if ((al & 0x0f) > 9 || af) {
2459 al -= 6;
2460 cf = old_cf | (al >= 250);
2461 af = true;
2462 } else {
2463 af = false;
2464 }
2465 if (old_al > 0x99 || old_cf) {
2466 al -= 0x60;
2467 cf = true;
2468 }
2469
2470 ctxt->dst.val = al;
2471 /* Set PF, ZF, SF */
2472 ctxt->src.type = OP_IMM;
2473 ctxt->src.val = 0;
2474 ctxt->src.bytes = 1;
2475 emulate_2op_SrcV(ctxt, "or");
2476 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);
2477 if (cf)
2478 ctxt->eflags |= X86_EFLAGS_CF;
2479 if (af)
2480 ctxt->eflags |= X86_EFLAGS_AF;
2481 return X86EMUL_CONTINUE;
2482 }
2483
2484 static int em_call_far(struct x86_emulate_ctxt *ctxt)
2485 {
2486 u16 sel, old_cs;
2487 ulong old_eip;
2488 int rc;
2489
2490 old_cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2491 old_eip = ctxt->_eip;
2492
2493 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2494 if (load_segment_descriptor(ctxt, sel, VCPU_SREG_CS))
2495 return X86EMUL_CONTINUE;
2496
2497 ctxt->_eip = 0;
2498 memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
2499
2500 ctxt->src.val = old_cs;
2501 rc = em_push(ctxt);
2502 if (rc != X86EMUL_CONTINUE)
2503 return rc;
2504
2505 ctxt->src.val = old_eip;
2506 return em_push(ctxt);
2507 }
2508
2509 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
2510 {
2511 int rc;
2512
2513 ctxt->dst.type = OP_REG;
2514 ctxt->dst.addr.reg = &ctxt->_eip;
2515 ctxt->dst.bytes = ctxt->op_bytes;
2516 rc = emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
2517 if (rc != X86EMUL_CONTINUE)
2518 return rc;
2519 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], ctxt->src.val);
2520 return X86EMUL_CONTINUE;
2521 }
2522
2523 static int em_add(struct x86_emulate_ctxt *ctxt)
2524 {
2525 emulate_2op_SrcV(ctxt, "add");
2526 return X86EMUL_CONTINUE;
2527 }
2528
2529 static int em_or(struct x86_emulate_ctxt *ctxt)
2530 {
2531 emulate_2op_SrcV(ctxt, "or");
2532 return X86EMUL_CONTINUE;
2533 }
2534
2535 static int em_adc(struct x86_emulate_ctxt *ctxt)
2536 {
2537 emulate_2op_SrcV(ctxt, "adc");
2538 return X86EMUL_CONTINUE;
2539 }
2540
2541 static int em_sbb(struct x86_emulate_ctxt *ctxt)
2542 {
2543 emulate_2op_SrcV(ctxt, "sbb");
2544 return X86EMUL_CONTINUE;
2545 }
2546
2547 static int em_and(struct x86_emulate_ctxt *ctxt)
2548 {
2549 emulate_2op_SrcV(ctxt, "and");
2550 return X86EMUL_CONTINUE;
2551 }
2552
2553 static int em_sub(struct x86_emulate_ctxt *ctxt)
2554 {
2555 emulate_2op_SrcV(ctxt, "sub");
2556 return X86EMUL_CONTINUE;
2557 }
2558
2559 static int em_xor(struct x86_emulate_ctxt *ctxt)
2560 {
2561 emulate_2op_SrcV(ctxt, "xor");
2562 return X86EMUL_CONTINUE;
2563 }
2564
2565 static int em_cmp(struct x86_emulate_ctxt *ctxt)
2566 {
2567 emulate_2op_SrcV(ctxt, "cmp");
2568 /* Disable writeback. */
2569 ctxt->dst.type = OP_NONE;
2570 return X86EMUL_CONTINUE;
2571 }
2572
2573 static int em_test(struct x86_emulate_ctxt *ctxt)
2574 {
2575 emulate_2op_SrcV(ctxt, "test");
2576 /* Disable writeback. */
2577 ctxt->dst.type = OP_NONE;
2578 return X86EMUL_CONTINUE;
2579 }
2580
2581 static int em_xchg(struct x86_emulate_ctxt *ctxt)
2582 {
2583 /* Write back the register source. */
2584 ctxt->src.val = ctxt->dst.val;
2585 write_register_operand(&ctxt->src);
2586
2587 /* Write back the memory destination with implicit LOCK prefix. */
2588 ctxt->dst.val = ctxt->src.orig_val;
2589 ctxt->lock_prefix = 1;
2590 return X86EMUL_CONTINUE;
2591 }
2592
2593 static int em_imul(struct x86_emulate_ctxt *ctxt)
2594 {
2595 emulate_2op_SrcV_nobyte(ctxt, "imul");
2596 return X86EMUL_CONTINUE;
2597 }
2598
2599 static int em_imul_3op(struct x86_emulate_ctxt *ctxt)
2600 {
2601 ctxt->dst.val = ctxt->src2.val;
2602 return em_imul(ctxt);
2603 }
2604
2605 static int em_cwd(struct x86_emulate_ctxt *ctxt)
2606 {
2607 ctxt->dst.type = OP_REG;
2608 ctxt->dst.bytes = ctxt->src.bytes;
2609 ctxt->dst.addr.reg = &ctxt->regs[VCPU_REGS_RDX];
2610 ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1);
2611
2612 return X86EMUL_CONTINUE;
2613 }
2614
2615 static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
2616 {
2617 u64 tsc = 0;
2618
2619 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc);
2620 ctxt->regs[VCPU_REGS_RAX] = (u32)tsc;
2621 ctxt->regs[VCPU_REGS_RDX] = tsc >> 32;
2622 return X86EMUL_CONTINUE;
2623 }
2624
2625 static int em_mov(struct x86_emulate_ctxt *ctxt)
2626 {
2627 ctxt->dst.val = ctxt->src.val;
2628 return X86EMUL_CONTINUE;
2629 }
2630
2631 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
2632 {
2633 if (ctxt->modrm_reg > VCPU_SREG_GS)
2634 return emulate_ud(ctxt);
2635
2636 ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);
2637 return X86EMUL_CONTINUE;
2638 }
2639
2640 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
2641 {
2642 u16 sel = ctxt->src.val;
2643
2644 if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS)
2645 return emulate_ud(ctxt);
2646
2647 if (ctxt->modrm_reg == VCPU_SREG_SS)
2648 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
2649
2650 /* Disable writeback. */
2651 ctxt->dst.type = OP_NONE;
2652 return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);
2653 }
2654
2655 static int em_movdqu(struct x86_emulate_ctxt *ctxt)
2656 {
2657 memcpy(&ctxt->dst.vec_val, &ctxt->src.vec_val, ctxt->op_bytes);
2658 return X86EMUL_CONTINUE;
2659 }
2660
2661 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
2662 {
2663 int rc;
2664 ulong linear;
2665
2666 rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear);
2667 if (rc == X86EMUL_CONTINUE)
2668 ctxt->ops->invlpg(ctxt, linear);
2669 /* Disable writeback. */
2670 ctxt->dst.type = OP_NONE;
2671 return X86EMUL_CONTINUE;
2672 }
2673
2674 static int em_clts(struct x86_emulate_ctxt *ctxt)
2675 {
2676 ulong cr0;
2677
2678 cr0 = ctxt->ops->get_cr(ctxt, 0);
2679 cr0 &= ~X86_CR0_TS;
2680 ctxt->ops->set_cr(ctxt, 0, cr0);
2681 return X86EMUL_CONTINUE;
2682 }
2683
2684 static int em_vmcall(struct x86_emulate_ctxt *ctxt)
2685 {
2686 int rc;
2687
2688 if (ctxt->modrm_mod != 3 || ctxt->modrm_rm != 1)
2689 return X86EMUL_UNHANDLEABLE;
2690
2691 rc = ctxt->ops->fix_hypercall(ctxt);
2692 if (rc != X86EMUL_CONTINUE)
2693 return rc;
2694
2695 /* Let the processor re-execute the fixed hypercall */
2696 ctxt->_eip = ctxt->eip;
2697 /* Disable writeback. */
2698 ctxt->dst.type = OP_NONE;
2699 return X86EMUL_CONTINUE;
2700 }
2701
2702 static int em_lgdt(struct x86_emulate_ctxt *ctxt)
2703 {
2704 struct desc_ptr desc_ptr;
2705 int rc;
2706
2707 rc = read_descriptor(ctxt, ctxt->src.addr.mem,
2708 &desc_ptr.size, &desc_ptr.address,
2709 ctxt->op_bytes);
2710 if (rc != X86EMUL_CONTINUE)
2711 return rc;
2712 ctxt->ops->set_gdt(ctxt, &desc_ptr);
2713 /* Disable writeback. */
2714 ctxt->dst.type = OP_NONE;
2715 return X86EMUL_CONTINUE;
2716 }
2717
2718 static int em_vmmcall(struct x86_emulate_ctxt *ctxt)
2719 {
2720 int rc;
2721
2722 rc = ctxt->ops->fix_hypercall(ctxt);
2723
2724 /* Disable writeback. */
2725 ctxt->dst.type = OP_NONE;
2726 return rc;
2727 }
2728
2729 static int em_lidt(struct x86_emulate_ctxt *ctxt)
2730 {
2731 struct desc_ptr desc_ptr;
2732 int rc;
2733
2734 rc = read_descriptor(ctxt, ctxt->src.addr.mem,
2735 &desc_ptr.size, &desc_ptr.address,
2736 ctxt->op_bytes);
2737 if (rc != X86EMUL_CONTINUE)
2738 return rc;
2739 ctxt->ops->set_idt(ctxt, &desc_ptr);
2740 /* Disable writeback. */
2741 ctxt->dst.type = OP_NONE;
2742 return X86EMUL_CONTINUE;
2743 }
2744
2745 static int em_smsw(struct x86_emulate_ctxt *ctxt)
2746 {
2747 ctxt->dst.bytes = 2;
2748 ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0);
2749 return X86EMUL_CONTINUE;
2750 }
2751
2752 static int em_lmsw(struct x86_emulate_ctxt *ctxt)
2753 {
2754 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul)
2755 | (ctxt->src.val & 0x0f));
2756 ctxt->dst.type = OP_NONE;
2757 return X86EMUL_CONTINUE;
2758 }
2759
2760 static int em_loop(struct x86_emulate_ctxt *ctxt)
2761 {
2762 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1);
2763 if ((address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) != 0) &&
2764 (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags)))
2765 jmp_rel(ctxt, ctxt->src.val);
2766
2767 return X86EMUL_CONTINUE;
2768 }
2769
2770 static int em_jcxz(struct x86_emulate_ctxt *ctxt)
2771 {
2772 if (address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) == 0)
2773 jmp_rel(ctxt, ctxt->src.val);
2774
2775 return X86EMUL_CONTINUE;
2776 }
2777
2778 static int em_cli(struct x86_emulate_ctxt *ctxt)
2779 {
2780 if (emulator_bad_iopl(ctxt))
2781 return emulate_gp(ctxt, 0);
2782
2783 ctxt->eflags &= ~X86_EFLAGS_IF;
2784 return X86EMUL_CONTINUE;
2785 }
2786
2787 static int em_sti(struct x86_emulate_ctxt *ctxt)
2788 {
2789 if (emulator_bad_iopl(ctxt))
2790 return emulate_gp(ctxt, 0);
2791
2792 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
2793 ctxt->eflags |= X86_EFLAGS_IF;
2794 return X86EMUL_CONTINUE;
2795 }
2796
2797 static bool valid_cr(int nr)
2798 {
2799 switch (nr) {
2800 case 0:
2801 case 2 ... 4:
2802 case 8:
2803 return true;
2804 default:
2805 return false;
2806 }
2807 }
2808
2809 static int check_cr_read(struct x86_emulate_ctxt *ctxt)
2810 {
2811 if (!valid_cr(ctxt->modrm_reg))
2812 return emulate_ud(ctxt);
2813
2814 return X86EMUL_CONTINUE;
2815 }
2816
2817 static int check_cr_write(struct x86_emulate_ctxt *ctxt)
2818 {
2819 u64 new_val = ctxt->src.val64;
2820 int cr = ctxt->modrm_reg;
2821 u64 efer = 0;
2822
2823 static u64 cr_reserved_bits[] = {
2824 0xffffffff00000000ULL,
2825 0, 0, 0, /* CR3 checked later */
2826 CR4_RESERVED_BITS,
2827 0, 0, 0,
2828 CR8_RESERVED_BITS,
2829 };
2830
2831 if (!valid_cr(cr))
2832 return emulate_ud(ctxt);
2833
2834 if (new_val & cr_reserved_bits[cr])
2835 return emulate_gp(ctxt, 0);
2836
2837 switch (cr) {
2838 case 0: {
2839 u64 cr4;
2840 if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) ||
2841 ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD)))
2842 return emulate_gp(ctxt, 0);
2843
2844 cr4 = ctxt->ops->get_cr(ctxt, 4);
2845 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
2846
2847 if ((new_val & X86_CR0_PG) && (efer & EFER_LME) &&
2848 !(cr4 & X86_CR4_PAE))
2849 return emulate_gp(ctxt, 0);
2850
2851 break;
2852 }
2853 case 3: {
2854 u64 rsvd = 0;
2855
2856 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
2857 if (efer & EFER_LMA)
2858 rsvd = CR3_L_MODE_RESERVED_BITS;
2859 else if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PAE)
2860 rsvd = CR3_PAE_RESERVED_BITS;
2861 else if (ctxt->ops->get_cr(ctxt, 0) & X86_CR0_PG)
2862 rsvd = CR3_NONPAE_RESERVED_BITS;
2863
2864 if (new_val & rsvd)
2865 return emulate_gp(ctxt, 0);
2866
2867 break;
2868 }
2869 case 4: {
2870 u64 cr4;
2871
2872 cr4 = ctxt->ops->get_cr(ctxt, 4);
2873 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
2874
2875 if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE))
2876 return emulate_gp(ctxt, 0);
2877
2878 break;
2879 }
2880 }
2881
2882 return X86EMUL_CONTINUE;
2883 }
2884
2885 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt)
2886 {
2887 unsigned long dr7;
2888
2889 ctxt->ops->get_dr(ctxt, 7, &dr7);
2890
2891 /* Check if DR7.Global_Enable is set */
2892 return dr7 & (1 << 13);
2893 }
2894
2895 static int check_dr_read(struct x86_emulate_ctxt *ctxt)
2896 {
2897 int dr = ctxt->modrm_reg;
2898 u64 cr4;
2899
2900 if (dr > 7)
2901 return emulate_ud(ctxt);
2902
2903 cr4 = ctxt->ops->get_cr(ctxt, 4);
2904 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
2905 return emulate_ud(ctxt);
2906
2907 if (check_dr7_gd(ctxt))
2908 return emulate_db(ctxt);
2909
2910 return X86EMUL_CONTINUE;
2911 }
2912
2913 static int check_dr_write(struct x86_emulate_ctxt *ctxt)
2914 {
2915 u64 new_val = ctxt->src.val64;
2916 int dr = ctxt->modrm_reg;
2917
2918 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL))
2919 return emulate_gp(ctxt, 0);
2920
2921 return check_dr_read(ctxt);
2922 }
2923
2924 static int check_svme(struct x86_emulate_ctxt *ctxt)
2925 {
2926 u64 efer;
2927
2928 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
2929
2930 if (!(efer & EFER_SVME))
2931 return emulate_ud(ctxt);
2932
2933 return X86EMUL_CONTINUE;
2934 }
2935
2936 static int check_svme_pa(struct x86_emulate_ctxt *ctxt)
2937 {
2938 u64 rax = ctxt->regs[VCPU_REGS_RAX];
2939
2940 /* Valid physical address? */
2941 if (rax & 0xffff000000000000ULL)
2942 return emulate_gp(ctxt, 0);
2943
2944 return check_svme(ctxt);
2945 }
2946
2947 static int check_rdtsc(struct x86_emulate_ctxt *ctxt)
2948 {
2949 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
2950
2951 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt))
2952 return emulate_ud(ctxt);
2953
2954 return X86EMUL_CONTINUE;
2955 }
2956
2957 static int check_rdpmc(struct x86_emulate_ctxt *ctxt)
2958 {
2959 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
2960 u64 rcx = ctxt->regs[VCPU_REGS_RCX];
2961
2962 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) ||
2963 (rcx > 3))
2964 return emulate_gp(ctxt, 0);
2965
2966 return X86EMUL_CONTINUE;
2967 }
2968
2969 static int check_perm_in(struct x86_emulate_ctxt *ctxt)
2970 {
2971 ctxt->dst.bytes = min(ctxt->dst.bytes, 4u);
2972 if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes))
2973 return emulate_gp(ctxt, 0);
2974
2975 return X86EMUL_CONTINUE;
2976 }
2977
2978 static int check_perm_out(struct x86_emulate_ctxt *ctxt)
2979 {
2980 ctxt->src.bytes = min(ctxt->src.bytes, 4u);
2981 if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes))
2982 return emulate_gp(ctxt, 0);
2983
2984 return X86EMUL_CONTINUE;
2985 }
2986
2987 #define D(_y) { .flags = (_y) }
2988 #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i }
2989 #define DIP(_y, _i, _p) { .flags = (_y), .intercept = x86_intercept_##_i, \
2990 .check_perm = (_p) }
2991 #define N D(0)
2992 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) }
2993 #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
2994 #define GD(_f, _g) { .flags = ((_f) | GroupDual), .u.gdual = (_g) }
2995 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
2996 #define II(_f, _e, _i) \
2997 { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i }
2998 #define IIP(_f, _e, _i, _p) \
2999 { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i, \
3000 .check_perm = (_p) }
3001 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }
3002
3003 #define D2bv(_f) D((_f) | ByteOp), D(_f)
3004 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p)
3005 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e)
3006
3007 #define I6ALU(_f, _e) I2bv((_f) | DstMem | SrcReg | ModRM, _e), \
3008 I2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \
3009 I2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)
3010
3011 static struct opcode group7_rm1[] = {
3012 DI(SrcNone | ModRM | Priv, monitor),
3013 DI(SrcNone | ModRM | Priv, mwait),
3014 N, N, N, N, N, N,
3015 };
3016
3017 static struct opcode group7_rm3[] = {
3018 DIP(SrcNone | ModRM | Prot | Priv, vmrun, check_svme_pa),
3019 II(SrcNone | ModRM | Prot | VendorSpecific, em_vmmcall, vmmcall),
3020 DIP(SrcNone | ModRM | Prot | Priv, vmload, check_svme_pa),
3021 DIP(SrcNone | ModRM | Prot | Priv, vmsave, check_svme_pa),
3022 DIP(SrcNone | ModRM | Prot | Priv, stgi, check_svme),
3023 DIP(SrcNone | ModRM | Prot | Priv, clgi, check_svme),
3024 DIP(SrcNone | ModRM | Prot | Priv, skinit, check_svme),
3025 DIP(SrcNone | ModRM | Prot | Priv, invlpga, check_svme),
3026 };
3027
3028 static struct opcode group7_rm7[] = {
3029 N,
3030 DIP(SrcNone | ModRM, rdtscp, check_rdtsc),
3031 N, N, N, N, N, N,
3032 };
3033
3034 static struct opcode group1[] = {
3035 I(Lock, em_add),
3036 I(Lock, em_or),
3037 I(Lock, em_adc),
3038 I(Lock, em_sbb),
3039 I(Lock, em_and),
3040 I(Lock, em_sub),
3041 I(Lock, em_xor),
3042 I(0, em_cmp),
3043 };
3044
3045 static struct opcode group1A[] = {
3046 D(DstMem | SrcNone | ModRM | Mov | Stack), N, N, N, N, N, N, N,
3047 };
3048
3049 static struct opcode group3[] = {
3050 I(DstMem | SrcImm | ModRM, em_test),
3051 I(DstMem | SrcImm | ModRM, em_test),
3052 I(DstMem | SrcNone | ModRM | Lock, em_not),
3053 I(DstMem | SrcNone | ModRM | Lock, em_neg),
3054 I(SrcMem | ModRM, em_mul_ex),
3055 I(SrcMem | ModRM, em_imul_ex),
3056 I(SrcMem | ModRM, em_div_ex),
3057 I(SrcMem | ModRM, em_idiv_ex),
3058 };
3059
3060 static struct opcode group4[] = {
3061 D(ByteOp | DstMem | SrcNone | ModRM | Lock), D(ByteOp | DstMem | SrcNone | ModRM | Lock),
3062 N, N, N, N, N, N,
3063 };
3064
3065 static struct opcode group5[] = {
3066 D(DstMem | SrcNone | ModRM | Lock), D(DstMem | SrcNone | ModRM | Lock),
3067 D(SrcMem | ModRM | Stack),
3068 I(SrcMemFAddr | ModRM | ImplicitOps | Stack, em_call_far),
3069 D(SrcMem | ModRM | Stack), D(SrcMemFAddr | ModRM | ImplicitOps),
3070 D(SrcMem | ModRM | Stack), N,
3071 };
3072
3073 static struct opcode group6[] = {
3074 DI(ModRM | Prot, sldt),
3075 DI(ModRM | Prot, str),
3076 DI(ModRM | Prot | Priv, lldt),
3077 DI(ModRM | Prot | Priv, ltr),
3078 N, N, N, N,
3079 };
3080
3081 static struct group_dual group7 = { {
3082 DI(ModRM | Mov | DstMem | Priv, sgdt),
3083 DI(ModRM | Mov | DstMem | Priv, sidt),
3084 II(ModRM | SrcMem | Priv, em_lgdt, lgdt),
3085 II(ModRM | SrcMem | Priv, em_lidt, lidt),
3086 II(SrcNone | ModRM | DstMem | Mov, em_smsw, smsw), N,
3087 II(SrcMem16 | ModRM | Mov | Priv, em_lmsw, lmsw),
3088 II(SrcMem | ModRM | ByteOp | Priv | NoAccess, em_invlpg, invlpg),
3089 }, {
3090 I(SrcNone | ModRM | Priv | VendorSpecific, em_vmcall),
3091 EXT(0, group7_rm1),
3092 N, EXT(0, group7_rm3),
3093 II(SrcNone | ModRM | DstMem | Mov, em_smsw, smsw), N,
3094 II(SrcMem16 | ModRM | Mov | Priv, em_lmsw, lmsw), EXT(0, group7_rm7),
3095 } };
3096
3097 static struct opcode group8[] = {
3098 N, N, N, N,
3099 D(DstMem | SrcImmByte | ModRM), D(DstMem | SrcImmByte | ModRM | Lock),
3100 D(DstMem | SrcImmByte | ModRM | Lock), D(DstMem | SrcImmByte | ModRM | Lock),
3101 };
3102
3103 static struct group_dual group9 = { {
3104 N, D(DstMem64 | ModRM | Lock), N, N, N, N, N, N,
3105 }, {
3106 N, N, N, N, N, N, N, N,
3107 } };
3108
3109 static struct opcode group11[] = {
3110 I(DstMem | SrcImm | ModRM | Mov, em_mov), X7(D(Undefined)),
3111 };
3112
3113 static struct gprefix pfx_0f_6f_0f_7f = {
3114 N, N, N, I(Sse, em_movdqu),
3115 };
3116
3117 static struct opcode opcode_table[256] = {
3118 /* 0x00 - 0x07 */
3119 I6ALU(Lock, em_add),
3120 I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg),
3121 I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg),
3122 /* 0x08 - 0x0F */
3123 I6ALU(Lock, em_or),
3124 I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg),
3125 N,
3126 /* 0x10 - 0x17 */
3127 I6ALU(Lock, em_adc),
3128 I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg),
3129 I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg),
3130 /* 0x18 - 0x1F */
3131 I6ALU(Lock, em_sbb),
3132 I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg),
3133 I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg),
3134 /* 0x20 - 0x27 */
3135 I6ALU(Lock, em_and), N, N,
3136 /* 0x28 - 0x2F */
3137 I6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),
3138 /* 0x30 - 0x37 */
3139 I6ALU(Lock, em_xor), N, N,
3140 /* 0x38 - 0x3F */
3141 I6ALU(0, em_cmp), N, N,
3142 /* 0x40 - 0x4F */
3143 X16(D(DstReg)),
3144 /* 0x50 - 0x57 */
3145 X8(I(SrcReg | Stack, em_push)),
3146 /* 0x58 - 0x5F */
3147 X8(I(DstReg | Stack, em_pop)),
3148 /* 0x60 - 0x67 */
3149 I(ImplicitOps | Stack | No64, em_pusha),
3150 I(ImplicitOps | Stack | No64, em_popa),
3151 N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ ,
3152 N, N, N, N,
3153 /* 0x68 - 0x6F */
3154 I(SrcImm | Mov | Stack, em_push),
3155 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
3156 I(SrcImmByte | Mov | Stack, em_push),
3157 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
3158 D2bvIP(DstDI | SrcDX | Mov | String, ins, check_perm_in), /* insb, insw/insd */
3159 D2bvIP(SrcSI | DstDX | String, outs, check_perm_out), /* outsb, outsw/outsd */
3160 /* 0x70 - 0x7F */
3161 X16(D(SrcImmByte)),
3162 /* 0x80 - 0x87 */
3163 G(ByteOp | DstMem | SrcImm | ModRM | Group, group1),
3164 G(DstMem | SrcImm | ModRM | Group, group1),
3165 G(ByteOp | DstMem | SrcImm | ModRM | No64 | Group, group1),
3166 G(DstMem | SrcImmByte | ModRM | Group, group1),
3167 I2bv(DstMem | SrcReg | ModRM, em_test),
3168 I2bv(DstMem | SrcReg | ModRM | Lock, em_xchg),
3169 /* 0x88 - 0x8F */
3170 I2bv(DstMem | SrcReg | ModRM | Mov, em_mov),
3171 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
3172 I(DstMem | SrcNone | ModRM | Mov, em_mov_rm_sreg),
3173 D(ModRM | SrcMem | NoAccess | DstReg),
3174 I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm),
3175 G(0, group1A),
3176 /* 0x90 - 0x97 */
3177 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)),
3178 /* 0x98 - 0x9F */
3179 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
3180 I(SrcImmFAddr | No64, em_call_far), N,
3181 II(ImplicitOps | Stack, em_pushf, pushf),
3182 II(ImplicitOps | Stack, em_popf, popf), N, N,
3183 /* 0xA0 - 0xA7 */
3184 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
3185 I2bv(DstMem | SrcAcc | Mov | MemAbs, em_mov),
3186 I2bv(SrcSI | DstDI | Mov | String, em_mov),
3187 I2bv(SrcSI | DstDI | String, em_cmp),
3188 /* 0xA8 - 0xAF */
3189 I2bv(DstAcc | SrcImm, em_test),
3190 I2bv(SrcAcc | DstDI | Mov | String, em_mov),
3191 I2bv(SrcSI | DstAcc | Mov | String, em_mov),
3192 I2bv(SrcAcc | DstDI | String, em_cmp),
3193 /* 0xB0 - 0xB7 */
3194 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
3195 /* 0xB8 - 0xBF */
3196 X8(I(DstReg | SrcImm | Mov, em_mov)),
3197 /* 0xC0 - 0xC7 */
3198 D2bv(DstMem | SrcImmByte | ModRM),
3199 I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),
3200 I(ImplicitOps | Stack, em_ret),
3201 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),
3202 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
3203 G(ByteOp, group11), G(0, group11),
3204 /* 0xC8 - 0xCF */
3205 N, N, N, I(ImplicitOps | Stack, em_ret_far),
3206 D(ImplicitOps), DI(SrcImmByte, intn),
3207 D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
3208 /* 0xD0 - 0xD7 */
3209 D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM),
3210 N, N, N, N,
3211 /* 0xD8 - 0xDF */
3212 N, N, N, N, N, N, N, N,
3213 /* 0xE0 - 0xE7 */
3214 X3(I(SrcImmByte, em_loop)),
3215 I(SrcImmByte, em_jcxz),
3216 D2bvIP(SrcImmUByte | DstAcc, in, check_perm_in),
3217 D2bvIP(SrcAcc | DstImmUByte, out, check_perm_out),
3218 /* 0xE8 - 0xEF */
3219 D(SrcImm | Stack), D(SrcImm | ImplicitOps),
3220 I(SrcImmFAddr | No64, em_jmp_far), D(SrcImmByte | ImplicitOps),
3221 D2bvIP(SrcDX | DstAcc, in, check_perm_in),
3222 D2bvIP(SrcAcc | DstDX, out, check_perm_out),
3223 /* 0xF0 - 0xF7 */
3224 N, DI(ImplicitOps, icebp), N, N,
3225 DI(ImplicitOps | Priv, hlt), D(ImplicitOps),
3226 G(ByteOp, group3), G(0, group3),
3227 /* 0xF8 - 0xFF */
3228 D(ImplicitOps), D(ImplicitOps),
3229 I(ImplicitOps, em_cli), I(ImplicitOps, em_sti),
3230 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5),
3231 };
3232
3233 static struct opcode twobyte_table[256] = {
3234 /* 0x00 - 0x0F */
3235 G(0, group6), GD(0, &group7), N, N,
3236 N, I(ImplicitOps | VendorSpecific, em_syscall),
3237 II(ImplicitOps | Priv, em_clts, clts), N,
3238 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N,
3239 N, D(ImplicitOps | ModRM), N, N,
3240 /* 0x10 - 0x1F */
3241 N, N, N, N, N, N, N, N, D(ImplicitOps | ModRM), N, N, N, N, N, N, N,
3242 /* 0x20 - 0x2F */
3243 DIP(ModRM | DstMem | Priv | Op3264, cr_read, check_cr_read),
3244 DIP(ModRM | DstMem | Priv | Op3264, dr_read, check_dr_read),
3245 DIP(ModRM | SrcMem | Priv | Op3264, cr_write, check_cr_write),
3246 DIP(ModRM | SrcMem | Priv | Op3264, dr_write, check_dr_write),
3247 N, N, N, N,
3248 N, N, N, N, N, N, N, N,
3249 /* 0x30 - 0x3F */
3250 DI(ImplicitOps | Priv, wrmsr),
3251 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
3252 DI(ImplicitOps | Priv, rdmsr),
3253 DIP(ImplicitOps | Priv, rdpmc, check_rdpmc),
3254 I(ImplicitOps | VendorSpecific, em_sysenter),
3255 I(ImplicitOps | Priv | VendorSpecific, em_sysexit),
3256 N, N,
3257 N, N, N, N, N, N, N, N,
3258 /* 0x40 - 0x4F */
3259 X16(D(DstReg | SrcMem | ModRM | Mov)),
3260 /* 0x50 - 0x5F */
3261 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3262 /* 0x60 - 0x6F */
3263 N, N, N, N,
3264 N, N, N, N,
3265 N, N, N, N,
3266 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f),
3267 /* 0x70 - 0x7F */
3268 N, N, N, N,
3269 N, N, N, N,
3270 N, N, N, N,
3271 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),
3272 /* 0x80 - 0x8F */
3273 X16(D(SrcImm)),
3274 /* 0x90 - 0x9F */
3275 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
3276 /* 0xA0 - 0xA7 */
3277 I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
3278 DI(ImplicitOps, cpuid), D(DstMem | SrcReg | ModRM | BitOp),
3279 D(DstMem | SrcReg | Src2ImmByte | ModRM),
3280 D(DstMem | SrcReg | Src2CL | ModRM), N, N,
3281 /* 0xA8 - 0xAF */
3282 I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
3283 DI(ImplicitOps, rsm), D(DstMem | SrcReg | ModRM | BitOp | Lock),
3284 D(DstMem | SrcReg | Src2ImmByte | ModRM),
3285 D(DstMem | SrcReg | Src2CL | ModRM),
3286 D(ModRM), I(DstReg | SrcMem | ModRM, em_imul),
3287 /* 0xB0 - 0xB7 */
3288 D2bv(DstMem | SrcReg | ModRM | Lock),
3289 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
3290 D(DstMem | SrcReg | ModRM | BitOp | Lock),
3291 I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
3292 I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
3293 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
3294 /* 0xB8 - 0xBF */
3295 N, N,
3296 G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock),
3297 D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM),
3298 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
3299 /* 0xC0 - 0xCF */
3300 D2bv(DstMem | SrcReg | ModRM | Lock),
3301 N, D(DstMem | SrcReg | ModRM | Mov),
3302 N, N, N, GD(0, &group9),
3303 N, N, N, N, N, N, N, N,
3304 /* 0xD0 - 0xDF */
3305 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3306 /* 0xE0 - 0xEF */
3307 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3308 /* 0xF0 - 0xFF */
3309 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N
3310 };
3311
3312 #undef D
3313 #undef N
3314 #undef G
3315 #undef GD
3316 #undef I
3317 #undef GP
3318 #undef EXT
3319
3320 #undef D2bv
3321 #undef D2bvIP
3322 #undef I2bv
3323 #undef I6ALU
3324
3325 static unsigned imm_size(struct x86_emulate_ctxt *ctxt)
3326 {
3327 unsigned size;
3328
3329 size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3330 if (size == 8)
3331 size = 4;
3332 return size;
3333 }
3334
3335 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op,
3336 unsigned size, bool sign_extension)
3337 {
3338 int rc = X86EMUL_CONTINUE;
3339
3340 op->type = OP_IMM;
3341 op->bytes = size;
3342 op->addr.mem.ea = ctxt->_eip;
3343 /* NB. Immediates are sign-extended as necessary. */
3344 switch (op->bytes) {
3345 case 1:
3346 op->val = insn_fetch(s8, ctxt);
3347 break;
3348 case 2:
3349 op->val = insn_fetch(s16, ctxt);
3350 break;
3351 case 4:
3352 op->val = insn_fetch(s32, ctxt);
3353 break;
3354 }
3355 if (!sign_extension) {
3356 switch (op->bytes) {
3357 case 1:
3358 op->val &= 0xff;
3359 break;
3360 case 2:
3361 op->val &= 0xffff;
3362 break;
3363 case 4:
3364 op->val &= 0xffffffff;
3365 break;
3366 }
3367 }
3368 done:
3369 return rc;
3370 }
3371
3372 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
3373 unsigned d)
3374 {
3375 int rc = X86EMUL_CONTINUE;
3376
3377 switch (d) {
3378 case OpReg:
3379 decode_register_operand(ctxt, op,
3380 op == &ctxt->dst &&
3381 ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));
3382 break;
3383 case OpImmUByte:
3384 rc = decode_imm(ctxt, op, 1, false);
3385 break;
3386 case OpMem:
3387 ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3388 mem_common:
3389 *op = ctxt->memop;
3390 ctxt->memopp = op;
3391 if ((ctxt->d & BitOp) && op == &ctxt->dst)
3392 fetch_bit_operand(ctxt);
3393 op->orig_val = op->val;
3394 break;
3395 case OpMem64:
3396 ctxt->memop.bytes = 8;
3397 goto mem_common;
3398 case OpAcc:
3399 op->type = OP_REG;
3400 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3401 op->addr.reg = &ctxt->regs[VCPU_REGS_RAX];
3402 fetch_register_operand(op);
3403 op->orig_val = op->val;
3404 break;
3405 case OpDI:
3406 op->type = OP_MEM;
3407 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3408 op->addr.mem.ea =
3409 register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]);
3410 op->addr.mem.seg = VCPU_SREG_ES;
3411 op->val = 0;
3412 break;
3413 case OpDX:
3414 op->type = OP_REG;
3415 op->bytes = 2;
3416 op->addr.reg = &ctxt->regs[VCPU_REGS_RDX];
3417 fetch_register_operand(op);
3418 break;
3419 case OpCL:
3420 op->bytes = 1;
3421 op->val = ctxt->regs[VCPU_REGS_RCX] & 0xff;
3422 break;
3423 case OpImmByte:
3424 rc = decode_imm(ctxt, op, 1, true);
3425 break;
3426 case OpOne:
3427 op->bytes = 1;
3428 op->val = 1;
3429 break;
3430 case OpImm:
3431 rc = decode_imm(ctxt, op, imm_size(ctxt), true);
3432 break;
3433 case OpMem16:
3434 ctxt->memop.bytes = 2;
3435 goto mem_common;
3436 case OpMem32:
3437 ctxt->memop.bytes = 4;
3438 goto mem_common;
3439 case OpImmU16:
3440 rc = decode_imm(ctxt, op, 2, false);
3441 break;
3442 case OpImmU:
3443 rc = decode_imm(ctxt, op, imm_size(ctxt), false);
3444 break;
3445 case OpSI:
3446 op->type = OP_MEM;
3447 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3448 op->addr.mem.ea =
3449 register_address(ctxt, ctxt->regs[VCPU_REGS_RSI]);
3450 op->addr.mem.seg = seg_override(ctxt);
3451 op->val = 0;
3452 break;
3453 case OpImmFAddr:
3454 op->type = OP_IMM;
3455 op->addr.mem.ea = ctxt->_eip;
3456 op->bytes = ctxt->op_bytes + 2;
3457 insn_fetch_arr(op->valptr, op->bytes, ctxt);
3458 break;
3459 case OpMemFAddr:
3460 ctxt->memop.bytes = ctxt->op_bytes + 2;
3461 goto mem_common;
3462 case OpES:
3463 op->val = VCPU_SREG_ES;
3464 break;
3465 case OpCS:
3466 op->val = VCPU_SREG_CS;
3467 break;
3468 case OpSS:
3469 op->val = VCPU_SREG_SS;
3470 break;
3471 case OpDS:
3472 op->val = VCPU_SREG_DS;
3473 break;
3474 case OpFS:
3475 op->val = VCPU_SREG_FS;
3476 break;
3477 case OpGS:
3478 op->val = VCPU_SREG_GS;
3479 break;
3480 case OpImplicit:
3481 /* Special instructions do their own operand decoding. */
3482 default:
3483 op->type = OP_NONE; /* Disable writeback. */
3484 break;
3485 }
3486
3487 done:
3488 return rc;
3489 }
3490
3491 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
3492 {
3493 int rc = X86EMUL_CONTINUE;
3494 int mode = ctxt->mode;
3495 int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
3496 bool op_prefix = false;
3497 struct opcode opcode;
3498
3499 ctxt->memop.type = OP_NONE;
3500 ctxt->memopp = NULL;
3501 ctxt->_eip = ctxt->eip;
3502 ctxt->fetch.start = ctxt->_eip;
3503 ctxt->fetch.end = ctxt->fetch.start + insn_len;
3504 if (insn_len > 0)
3505 memcpy(ctxt->fetch.data, insn, insn_len);
3506
3507 switch (mode) {
3508 case X86EMUL_MODE_REAL:
3509 case X86EMUL_MODE_VM86:
3510 case X86EMUL_MODE_PROT16:
3511 def_op_bytes = def_ad_bytes = 2;
3512 break;
3513 case X86EMUL_MODE_PROT32:
3514 def_op_bytes = def_ad_bytes = 4;
3515 break;
3516 #ifdef CONFIG_X86_64
3517 case X86EMUL_MODE_PROT64:
3518 def_op_bytes = 4;
3519 def_ad_bytes = 8;
3520 break;
3521 #endif
3522 default:
3523 return EMULATION_FAILED;
3524 }
3525
3526 ctxt->op_bytes = def_op_bytes;
3527 ctxt->ad_bytes = def_ad_bytes;
3528
3529 /* Legacy prefixes. */
3530 for (;;) {
3531 switch (ctxt->b = insn_fetch(u8, ctxt)) {
3532 case 0x66: /* operand-size override */
3533 op_prefix = true;
3534 /* switch between 2/4 bytes */
3535 ctxt->op_bytes = def_op_bytes ^ 6;
3536 break;
3537 case 0x67: /* address-size override */
3538 if (mode == X86EMUL_MODE_PROT64)
3539 /* switch between 4/8 bytes */
3540 ctxt->ad_bytes = def_ad_bytes ^ 12;
3541 else
3542 /* switch between 2/4 bytes */
3543 ctxt->ad_bytes = def_ad_bytes ^ 6;
3544 break;
3545 case 0x26: /* ES override */
3546 case 0x2e: /* CS override */
3547 case 0x36: /* SS override */
3548 case 0x3e: /* DS override */
3549 set_seg_override(ctxt, (ctxt->b >> 3) & 3);
3550 break;
3551 case 0x64: /* FS override */
3552 case 0x65: /* GS override */
3553 set_seg_override(ctxt, ctxt->b & 7);
3554 break;
3555 case 0x40 ... 0x4f: /* REX */
3556 if (mode != X86EMUL_MODE_PROT64)
3557 goto done_prefixes;
3558 ctxt->rex_prefix = ctxt->b;
3559 continue;
3560 case 0xf0: /* LOCK */
3561 ctxt->lock_prefix = 1;
3562 break;
3563 case 0xf2: /* REPNE/REPNZ */
3564 case 0xf3: /* REP/REPE/REPZ */
3565 ctxt->rep_prefix = ctxt->b;
3566 break;
3567 default:
3568 goto done_prefixes;
3569 }
3570
3571 /* Any legacy prefix after a REX prefix nullifies its effect. */
3572
3573 ctxt->rex_prefix = 0;
3574 }
3575
3576 done_prefixes:
3577
3578 /* REX prefix. */
3579 if (ctxt->rex_prefix & 8)
3580 ctxt->op_bytes = 8; /* REX.W */
3581
3582 /* Opcode byte(s). */
3583 opcode = opcode_table[ctxt->b];
3584 /* Two-byte opcode? */
3585 if (ctxt->b == 0x0f) {
3586 ctxt->twobyte = 1;
3587 ctxt->b = insn_fetch(u8, ctxt);
3588 opcode = twobyte_table[ctxt->b];
3589 }
3590 ctxt->d = opcode.flags;
3591
3592 while (ctxt->d & GroupMask) {
3593 switch (ctxt->d & GroupMask) {
3594 case Group:
3595 ctxt->modrm = insn_fetch(u8, ctxt);
3596 --ctxt->_eip;
3597 goffset = (ctxt->modrm >> 3) & 7;
3598 opcode = opcode.u.group[goffset];
3599 break;
3600 case GroupDual:
3601 ctxt->modrm = insn_fetch(u8, ctxt);
3602 --ctxt->_eip;
3603 goffset = (ctxt->modrm >> 3) & 7;
3604 if ((ctxt->modrm >> 6) == 3)
3605 opcode = opcode.u.gdual->mod3[goffset];
3606 else
3607 opcode = opcode.u.gdual->mod012[goffset];
3608 break;
3609 case RMExt:
3610 goffset = ctxt->modrm & 7;
3611 opcode = opcode.u.group[goffset];
3612 break;
3613 case Prefix:
3614 if (ctxt->rep_prefix && op_prefix)
3615 return EMULATION_FAILED;
3616 simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
3617 switch (simd_prefix) {
3618 case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
3619 case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
3620 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
3621 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
3622 }
3623 break;
3624 default:
3625 return EMULATION_FAILED;
3626 }
3627
3628 ctxt->d &= ~(u64)GroupMask;
3629 ctxt->d |= opcode.flags;
3630 }
3631
3632 ctxt->execute = opcode.u.execute;
3633 ctxt->check_perm = opcode.check_perm;
3634 ctxt->intercept = opcode.intercept;
3635
3636 /* Unrecognised? */
3637 if (ctxt->d == 0 || (ctxt->d & Undefined))
3638 return EMULATION_FAILED;
3639
3640 if (!(ctxt->d & VendorSpecific) && ctxt->only_vendor_specific_insn)
3641 return EMULATION_FAILED;
3642
3643 if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack))
3644 ctxt->op_bytes = 8;
3645
3646 if (ctxt->d & Op3264) {
3647 if (mode == X86EMUL_MODE_PROT64)
3648 ctxt->op_bytes = 8;
3649 else
3650 ctxt->op_bytes = 4;
3651 }
3652
3653 if (ctxt->d & Sse)
3654 ctxt->op_bytes = 16;
3655
3656 /* ModRM and SIB bytes. */
3657 if (ctxt->d & ModRM) {
3658 rc = decode_modrm(ctxt, &ctxt->memop);
3659 if (!ctxt->has_seg_override)
3660 set_seg_override(ctxt, ctxt->modrm_seg);
3661 } else if (ctxt->d & MemAbs)
3662 rc = decode_abs(ctxt, &ctxt->memop);
3663 if (rc != X86EMUL_CONTINUE)
3664 goto done;
3665
3666 if (!ctxt->has_seg_override)
3667 set_seg_override(ctxt, VCPU_SREG_DS);
3668
3669 ctxt->memop.addr.mem.seg = seg_override(ctxt);
3670
3671 if (ctxt->memop.type == OP_MEM && ctxt->ad_bytes != 8)
3672 ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
3673
3674 /*
3675 * Decode and fetch the source operand: register, memory
3676 * or immediate.
3677 */
3678 rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask);
3679 if (rc != X86EMUL_CONTINUE)
3680 goto done;
3681
3682 /*
3683 * Decode and fetch the second source operand: register, memory
3684 * or immediate.
3685 */
3686 rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask);
3687 if (rc != X86EMUL_CONTINUE)
3688 goto done;
3689
3690 /* Decode and fetch the destination operand: register or memory. */
3691 rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
3692
3693 done:
3694 if (ctxt->memopp && ctxt->memopp->type == OP_MEM && ctxt->rip_relative)
3695 ctxt->memopp->addr.mem.ea += ctxt->_eip;
3696
3697 return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
3698 }
3699
3700 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
3701 {
3702 /* The second termination condition only applies for REPE
3703 * and REPNE. Test if the repeat string operation prefix is
3704 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
3705 * corresponding termination condition according to:
3706 * - if REPE/REPZ and ZF = 0 then done
3707 * - if REPNE/REPNZ and ZF = 1 then done
3708 */
3709 if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) ||
3710 (ctxt->b == 0xae) || (ctxt->b == 0xaf))
3711 && (((ctxt->rep_prefix == REPE_PREFIX) &&
3712 ((ctxt->eflags & EFLG_ZF) == 0))
3713 || ((ctxt->rep_prefix == REPNE_PREFIX) &&
3714 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
3715 return true;
3716
3717 return false;
3718 }
3719
3720 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
3721 {
3722 struct x86_emulate_ops *ops = ctxt->ops;
3723 u64 msr_data;
3724 int rc = X86EMUL_CONTINUE;
3725 int saved_dst_type = ctxt->dst.type;
3726
3727 ctxt->mem_read.pos = 0;
3728
3729 if (ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) {
3730 rc = emulate_ud(ctxt);
3731 goto done;
3732 }
3733
3734 /* LOCK prefix is allowed only with some instructions */
3735 if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) {
3736 rc = emulate_ud(ctxt);
3737 goto done;
3738 }
3739
3740 if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) {
3741 rc = emulate_ud(ctxt);
3742 goto done;
3743 }
3744
3745 if ((ctxt->d & Sse)
3746 && ((ops->get_cr(ctxt, 0) & X86_CR0_EM)
3747 || !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) {
3748 rc = emulate_ud(ctxt);
3749 goto done;
3750 }
3751
3752 if ((ctxt->d & Sse) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) {
3753 rc = emulate_nm(ctxt);
3754 goto done;
3755 }
3756
3757 if (unlikely(ctxt->guest_mode) && ctxt->intercept) {
3758 rc = emulator_check_intercept(ctxt, ctxt->intercept,
3759 X86_ICPT_PRE_EXCEPT);
3760 if (rc != X86EMUL_CONTINUE)
3761 goto done;
3762 }
3763
3764 /* Privileged instruction can be executed only in CPL=0 */
3765 if ((ctxt->d & Priv) && ops->cpl(ctxt)) {
3766 rc = emulate_gp(ctxt, 0);
3767 goto done;
3768 }
3769
3770 /* Instruction can only be executed in protected mode */
3771 if ((ctxt->d & Prot) && !(ctxt->mode & X86EMUL_MODE_PROT)) {
3772 rc = emulate_ud(ctxt);
3773 goto done;
3774 }
3775
3776 /* Do instruction specific permission checks */
3777 if (ctxt->check_perm) {
3778 rc = ctxt->check_perm(ctxt);
3779 if (rc != X86EMUL_CONTINUE)
3780 goto done;
3781 }
3782
3783 if (unlikely(ctxt->guest_mode) && ctxt->intercept) {
3784 rc = emulator_check_intercept(ctxt, ctxt->intercept,
3785 X86_ICPT_POST_EXCEPT);
3786 if (rc != X86EMUL_CONTINUE)
3787 goto done;
3788 }
3789
3790 if (ctxt->rep_prefix && (ctxt->d & String)) {
3791 /* All REP prefixes have the same first termination condition */
3792 if (address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) == 0) {
3793 ctxt->eip = ctxt->_eip;
3794 goto done;
3795 }
3796 }
3797
3798 if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) {
3799 rc = segmented_read(ctxt, ctxt->src.addr.mem,
3800 ctxt->src.valptr, ctxt->src.bytes);
3801 if (rc != X86EMUL_CONTINUE)
3802 goto done;
3803 ctxt->src.orig_val64 = ctxt->src.val64;
3804 }
3805
3806 if (ctxt->src2.type == OP_MEM) {
3807 rc = segmented_read(ctxt, ctxt->src2.addr.mem,
3808 &ctxt->src2.val, ctxt->src2.bytes);
3809 if (rc != X86EMUL_CONTINUE)
3810 goto done;
3811 }
3812
3813 if ((ctxt->d & DstMask) == ImplicitOps)
3814 goto special_insn;
3815
3816
3817 if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) {
3818 /* optimisation - avoid slow emulated read if Mov */
3819 rc = segmented_read(ctxt, ctxt->dst.addr.mem,
3820 &ctxt->dst.val, ctxt->dst.bytes);
3821 if (rc != X86EMUL_CONTINUE)
3822 goto done;
3823 }
3824 ctxt->dst.orig_val = ctxt->dst.val;
3825
3826 special_insn:
3827
3828 if (unlikely(ctxt->guest_mode) && ctxt->intercept) {
3829 rc = emulator_check_intercept(ctxt, ctxt->intercept,
3830 X86_ICPT_POST_MEMACCESS);
3831 if (rc != X86EMUL_CONTINUE)
3832 goto done;
3833 }
3834
3835 if (ctxt->execute) {
3836 rc = ctxt->execute(ctxt);
3837 if (rc != X86EMUL_CONTINUE)
3838 goto done;
3839 goto writeback;
3840 }
3841
3842 if (ctxt->twobyte)
3843 goto twobyte_insn;
3844
3845 switch (ctxt->b) {
3846 case 0x40 ... 0x47: /* inc r16/r32 */
3847 emulate_1op(ctxt, "inc");
3848 break;
3849 case 0x48 ... 0x4f: /* dec r16/r32 */
3850 emulate_1op(ctxt, "dec");
3851 break;
3852 case 0x63: /* movsxd */
3853 if (ctxt->mode != X86EMUL_MODE_PROT64)
3854 goto cannot_emulate;
3855 ctxt->dst.val = (s32) ctxt->src.val;
3856 break;
3857 case 0x6c: /* insb */
3858 case 0x6d: /* insw/insd */
3859 ctxt->src.val = ctxt->regs[VCPU_REGS_RDX];
3860 goto do_io_in;
3861 case 0x6e: /* outsb */
3862 case 0x6f: /* outsw/outsd */
3863 ctxt->dst.val = ctxt->regs[VCPU_REGS_RDX];
3864 goto do_io_out;
3865 break;
3866 case 0x70 ... 0x7f: /* jcc (short) */
3867 if (test_cc(ctxt->b, ctxt->eflags))
3868 jmp_rel(ctxt, ctxt->src.val);
3869 break;
3870 case 0x8d: /* lea r16/r32, m */
3871 ctxt->dst.val = ctxt->src.addr.mem.ea;
3872 break;
3873 case 0x8f: /* pop (sole member of Grp1a) */
3874 rc = em_grp1a(ctxt);
3875 break;
3876 case 0x90 ... 0x97: /* nop / xchg reg, rax */
3877 if (ctxt->dst.addr.reg == &ctxt->regs[VCPU_REGS_RAX])
3878 break;
3879 rc = em_xchg(ctxt);
3880 break;
3881 case 0x98: /* cbw/cwde/cdqe */
3882 switch (ctxt->op_bytes) {
3883 case 2: ctxt->dst.val = (s8)ctxt->dst.val; break;
3884 case 4: ctxt->dst.val = (s16)ctxt->dst.val; break;
3885 case 8: ctxt->dst.val = (s32)ctxt->dst.val; break;
3886 }
3887 break;
3888 case 0xc0 ... 0xc1:
3889 rc = em_grp2(ctxt);
3890 break;
3891 case 0xcc: /* int3 */
3892 rc = emulate_int(ctxt, 3);
3893 break;
3894 case 0xcd: /* int n */
3895 rc = emulate_int(ctxt, ctxt->src.val);
3896 break;
3897 case 0xce: /* into */
3898 if (ctxt->eflags & EFLG_OF)
3899 rc = emulate_int(ctxt, 4);
3900 break;
3901 case 0xd0 ... 0xd1: /* Grp2 */
3902 rc = em_grp2(ctxt);
3903 break;
3904 case 0xd2 ... 0xd3: /* Grp2 */
3905 ctxt->src.val = ctxt->regs[VCPU_REGS_RCX];
3906 rc = em_grp2(ctxt);
3907 break;
3908 case 0xe4: /* inb */
3909 case 0xe5: /* in */
3910 goto do_io_in;
3911 case 0xe6: /* outb */
3912 case 0xe7: /* out */
3913 goto do_io_out;
3914 case 0xe8: /* call (near) */ {
3915 long int rel = ctxt->src.val;
3916 ctxt->src.val = (unsigned long) ctxt->_eip;
3917 jmp_rel(ctxt, rel);
3918 rc = em_push(ctxt);
3919 break;
3920 }
3921 case 0xe9: /* jmp rel */
3922 case 0xeb: /* jmp rel short */
3923 jmp_rel(ctxt, ctxt->src.val);
3924 ctxt->dst.type = OP_NONE; /* Disable writeback. */
3925 break;
3926 case 0xec: /* in al,dx */
3927 case 0xed: /* in (e/r)ax,dx */
3928 do_io_in:
3929 if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val,
3930 &ctxt->dst.val))
3931 goto done; /* IO is needed */
3932 break;
3933 case 0xee: /* out dx,al */
3934 case 0xef: /* out dx,(e/r)ax */
3935 do_io_out:
3936 ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val,
3937 &ctxt->src.val, 1);
3938 ctxt->dst.type = OP_NONE; /* Disable writeback. */
3939 break;
3940 case 0xf4: /* hlt */
3941 ctxt->ops->halt(ctxt);
3942 break;
3943 case 0xf5: /* cmc */
3944 /* complement carry flag from eflags reg */
3945 ctxt->eflags ^= EFLG_CF;
3946 break;
3947 case 0xf8: /* clc */
3948 ctxt->eflags &= ~EFLG_CF;
3949 break;
3950 case 0xf9: /* stc */
3951 ctxt->eflags |= EFLG_CF;
3952 break;
3953 case 0xfc: /* cld */
3954 ctxt->eflags &= ~EFLG_DF;
3955 break;
3956 case 0xfd: /* std */
3957 ctxt->eflags |= EFLG_DF;
3958 break;
3959 case 0xfe: /* Grp4 */
3960 rc = em_grp45(ctxt);
3961 break;
3962 case 0xff: /* Grp5 */
3963 rc = em_grp45(ctxt);
3964 break;
3965 default:
3966 goto cannot_emulate;
3967 }
3968
3969 if (rc != X86EMUL_CONTINUE)
3970 goto done;
3971
3972 writeback:
3973 rc = writeback(ctxt);
3974 if (rc != X86EMUL_CONTINUE)
3975 goto done;
3976
3977 /*
3978 * restore dst type in case the decoding will be reused
3979 * (happens for string instruction )
3980 */
3981 ctxt->dst.type = saved_dst_type;
3982
3983 if ((ctxt->d & SrcMask) == SrcSI)
3984 string_addr_inc(ctxt, seg_override(ctxt),
3985 VCPU_REGS_RSI, &ctxt->src);
3986
3987 if ((ctxt->d & DstMask) == DstDI)
3988 string_addr_inc(ctxt, VCPU_SREG_ES, VCPU_REGS_RDI,
3989 &ctxt->dst);
3990
3991 if (ctxt->rep_prefix && (ctxt->d & String)) {
3992 struct read_cache *r = &ctxt->io_read;
3993 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1);
3994
3995 if (!string_insn_completed(ctxt)) {
3996 /*
3997 * Re-enter guest when pio read ahead buffer is empty
3998 * or, if it is not used, after each 1024 iteration.
3999 */
4000 if ((r->end != 0 || ctxt->regs[VCPU_REGS_RCX] & 0x3ff) &&
4001 (r->end == 0 || r->end != r->pos)) {
4002 /*
4003 * Reset read cache. Usually happens before
4004 * decode, but since instruction is restarted
4005 * we have to do it here.
4006 */
4007 ctxt->mem_read.end = 0;
4008 return EMULATION_RESTART;
4009 }
4010 goto done; /* skip rip writeback */
4011 }
4012 }
4013
4014 ctxt->eip = ctxt->_eip;
4015
4016 done:
4017 if (rc == X86EMUL_PROPAGATE_FAULT)
4018 ctxt->have_exception = true;
4019 if (rc == X86EMUL_INTERCEPTED)
4020 return EMULATION_INTERCEPTED;
4021
4022 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
4023
4024 twobyte_insn:
4025 switch (ctxt->b) {
4026 case 0x09: /* wbinvd */
4027 (ctxt->ops->wbinvd)(ctxt);
4028 break;
4029 case 0x08: /* invd */
4030 case 0x0d: /* GrpP (prefetch) */
4031 case 0x18: /* Grp16 (prefetch/nop) */
4032 break;
4033 case 0x20: /* mov cr, reg */
4034 ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg);
4035 break;
4036 case 0x21: /* mov from dr to reg */
4037 ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val);
4038 break;
4039 case 0x22: /* mov reg, cr */
4040 if (ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val)) {
4041 emulate_gp(ctxt, 0);
4042 rc = X86EMUL_PROPAGATE_FAULT;
4043 goto done;
4044 }
4045 ctxt->dst.type = OP_NONE;
4046 break;
4047 case 0x23: /* mov from reg to dr */
4048 if (ops->set_dr(ctxt, ctxt->modrm_reg, ctxt->src.val &
4049 ((ctxt->mode == X86EMUL_MODE_PROT64) ?
4050 ~0ULL : ~0U)) < 0) {
4051 /* #UD condition is already handled by the code above */
4052 emulate_gp(ctxt, 0);
4053 rc = X86EMUL_PROPAGATE_FAULT;
4054 goto done;
4055 }
4056
4057 ctxt->dst.type = OP_NONE; /* no writeback */
4058 break;
4059 case 0x30:
4060 /* wrmsr */
4061 msr_data = (u32)ctxt->regs[VCPU_REGS_RAX]
4062 | ((u64)ctxt->regs[VCPU_REGS_RDX] << 32);
4063 if (ops->set_msr(ctxt, ctxt->regs[VCPU_REGS_RCX], msr_data)) {
4064 emulate_gp(ctxt, 0);
4065 rc = X86EMUL_PROPAGATE_FAULT;
4066 goto done;
4067 }
4068 rc = X86EMUL_CONTINUE;
4069 break;
4070 case 0x32:
4071 /* rdmsr */
4072 if (ops->get_msr(ctxt, ctxt->regs[VCPU_REGS_RCX], &msr_data)) {
4073 emulate_gp(ctxt, 0);
4074 rc = X86EMUL_PROPAGATE_FAULT;
4075 goto done;
4076 } else {
4077 ctxt->regs[VCPU_REGS_RAX] = (u32)msr_data;
4078 ctxt->regs[VCPU_REGS_RDX] = msr_data >> 32;
4079 }
4080 rc = X86EMUL_CONTINUE;
4081 break;
4082 case 0x40 ... 0x4f: /* cmov */
4083 ctxt->dst.val = ctxt->dst.orig_val = ctxt->src.val;
4084 if (!test_cc(ctxt->b, ctxt->eflags))
4085 ctxt->dst.type = OP_NONE; /* no writeback */
4086 break;
4087 case 0x80 ... 0x8f: /* jnz rel, etc*/
4088 if (test_cc(ctxt->b, ctxt->eflags))
4089 jmp_rel(ctxt, ctxt->src.val);
4090 break;
4091 case 0x90 ... 0x9f: /* setcc r/m8 */
4092 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
4093 break;
4094 case 0xa3:
4095 bt: /* bt */
4096 ctxt->dst.type = OP_NONE;
4097 /* only subword offset */
4098 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
4099 emulate_2op_SrcV_nobyte(ctxt, "bt");
4100 break;
4101 case 0xa4: /* shld imm8, r, r/m */
4102 case 0xa5: /* shld cl, r, r/m */
4103 emulate_2op_cl(ctxt, "shld");
4104 break;
4105 case 0xab:
4106 bts: /* bts */
4107 emulate_2op_SrcV_nobyte(ctxt, "bts");
4108 break;
4109 case 0xac: /* shrd imm8, r, r/m */
4110 case 0xad: /* shrd cl, r, r/m */
4111 emulate_2op_cl(ctxt, "shrd");
4112 break;
4113 case 0xae: /* clflush */
4114 break;
4115 case 0xb0 ... 0xb1: /* cmpxchg */
4116 /*
4117 * Save real source value, then compare EAX against
4118 * destination.
4119 */
4120 ctxt->src.orig_val = ctxt->src.val;
4121 ctxt->src.val = ctxt->regs[VCPU_REGS_RAX];
4122 emulate_2op_SrcV(ctxt, "cmp");
4123 if (ctxt->eflags & EFLG_ZF) {
4124 /* Success: write back to memory. */
4125 ctxt->dst.val = ctxt->src.orig_val;
4126 } else {
4127 /* Failure: write the value we saw to EAX. */
4128 ctxt->dst.type = OP_REG;
4129 ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX];
4130 }
4131 break;
4132 case 0xb3:
4133 btr: /* btr */
4134 emulate_2op_SrcV_nobyte(ctxt, "btr");
4135 break;
4136 case 0xb6 ... 0xb7: /* movzx */
4137 ctxt->dst.bytes = ctxt->op_bytes;
4138 ctxt->dst.val = (ctxt->d & ByteOp) ? (u8) ctxt->src.val
4139 : (u16) ctxt->src.val;
4140 break;
4141 case 0xba: /* Grp8 */
4142 switch (ctxt->modrm_reg & 3) {
4143 case 0:
4144 goto bt;
4145 case 1:
4146 goto bts;
4147 case 2:
4148 goto btr;
4149 case 3:
4150 goto btc;
4151 }
4152 break;
4153 case 0xbb:
4154 btc: /* btc */
4155 emulate_2op_SrcV_nobyte(ctxt, "btc");
4156 break;
4157 case 0xbc: { /* bsf */
4158 u8 zf;
4159 __asm__ ("bsf %2, %0; setz %1"
4160 : "=r"(ctxt->dst.val), "=q"(zf)
4161 : "r"(ctxt->src.val));
4162 ctxt->eflags &= ~X86_EFLAGS_ZF;
4163 if (zf) {
4164 ctxt->eflags |= X86_EFLAGS_ZF;
4165 ctxt->dst.type = OP_NONE; /* Disable writeback. */
4166 }
4167 break;
4168 }
4169 case 0xbd: { /* bsr */
4170 u8 zf;
4171 __asm__ ("bsr %2, %0; setz %1"
4172 : "=r"(ctxt->dst.val), "=q"(zf)
4173 : "r"(ctxt->src.val));
4174 ctxt->eflags &= ~X86_EFLAGS_ZF;
4175 if (zf) {
4176 ctxt->eflags |= X86_EFLAGS_ZF;
4177 ctxt->dst.type = OP_NONE; /* Disable writeback. */
4178 }
4179 break;
4180 }
4181 case 0xbe ... 0xbf: /* movsx */
4182 ctxt->dst.bytes = ctxt->op_bytes;
4183 ctxt->dst.val = (ctxt->d & ByteOp) ? (s8) ctxt->src.val :
4184 (s16) ctxt->src.val;
4185 break;
4186 case 0xc0 ... 0xc1: /* xadd */
4187 emulate_2op_SrcV(ctxt, "add");
4188 /* Write back the register source. */
4189 ctxt->src.val = ctxt->dst.orig_val;
4190 write_register_operand(&ctxt->src);
4191 break;
4192 case 0xc3: /* movnti */
4193 ctxt->dst.bytes = ctxt->op_bytes;
4194 ctxt->dst.val = (ctxt->op_bytes == 4) ? (u32) ctxt->src.val :
4195 (u64) ctxt->src.val;
4196 break;
4197 case 0xc7: /* Grp9 (cmpxchg8b) */
4198 rc = em_grp9(ctxt);
4199 break;
4200 default:
4201 goto cannot_emulate;
4202 }
4203
4204 if (rc != X86EMUL_CONTINUE)
4205 goto done;
4206
4207 goto writeback;
4208
4209 cannot_emulate:
4210 return EMULATION_FAILED;
4211 }
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