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KVM: x86 emulator: define callbacks for using the guest fpu within the emulator
[deliverable/linux.git] / arch / x86 / kvm / emulate.c
1 /******************************************************************************
2 * emulate.c
3 *
4 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
5 *
6 * Copyright (c) 2005 Keir Fraser
7 *
8 * Linux coding style, mod r/m decoder, segment base fixes, real-mode
9 * privileged instructions:
10 *
11 * Copyright (C) 2006 Qumranet
12 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
13 *
14 * Avi Kivity <avi@qumranet.com>
15 * Yaniv Kamay <yaniv@qumranet.com>
16 *
17 * This work is licensed under the terms of the GNU GPL, version 2. See
18 * the COPYING file in the top-level directory.
19 *
20 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
21 */
22
23 #include <linux/kvm_host.h>
24 #include "kvm_cache_regs.h"
25 #include <linux/module.h>
26 #include <asm/kvm_emulate.h>
27
28 #include "x86.h"
29 #include "tss.h"
30
31 /*
32 * Opcode effective-address decode tables.
33 * Note that we only emulate instructions that have at least one memory
34 * operand (excluding implicit stack references). We assume that stack
35 * references and instruction fetches will never occur in special memory
36 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
37 * not be handled.
38 */
39
40 /* Operand sizes: 8-bit operands or specified/overridden size. */
41 #define ByteOp (1<<0) /* 8-bit operands. */
42 /* Destination operand type. */
43 #define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */
44 #define DstReg (2<<1) /* Register operand. */
45 #define DstMem (3<<1) /* Memory operand. */
46 #define DstAcc (4<<1) /* Destination Accumulator */
47 #define DstDI (5<<1) /* Destination is in ES:(E)DI */
48 #define DstMem64 (6<<1) /* 64bit memory operand */
49 #define DstImmUByte (7<<1) /* 8-bit unsigned immediate operand */
50 #define DstMask (7<<1)
51 /* Source operand type. */
52 #define SrcNone (0<<4) /* No source operand. */
53 #define SrcReg (1<<4) /* Register operand. */
54 #define SrcMem (2<<4) /* Memory operand. */
55 #define SrcMem16 (3<<4) /* Memory operand (16-bit). */
56 #define SrcMem32 (4<<4) /* Memory operand (32-bit). */
57 #define SrcImm (5<<4) /* Immediate operand. */
58 #define SrcImmByte (6<<4) /* 8-bit sign-extended immediate operand. */
59 #define SrcOne (7<<4) /* Implied '1' */
60 #define SrcImmUByte (8<<4) /* 8-bit unsigned immediate operand. */
61 #define SrcImmU (9<<4) /* Immediate operand, unsigned */
62 #define SrcSI (0xa<<4) /* Source is in the DS:RSI */
63 #define SrcImmFAddr (0xb<<4) /* Source is immediate far address */
64 #define SrcMemFAddr (0xc<<4) /* Source is far address in memory */
65 #define SrcAcc (0xd<<4) /* Source Accumulator */
66 #define SrcImmU16 (0xe<<4) /* Immediate operand, unsigned, 16 bits */
67 #define SrcMask (0xf<<4)
68 /* Generic ModRM decode. */
69 #define ModRM (1<<8)
70 /* Destination is only written; never read. */
71 #define Mov (1<<9)
72 #define BitOp (1<<10)
73 #define MemAbs (1<<11) /* Memory operand is absolute displacement */
74 #define String (1<<12) /* String instruction (rep capable) */
75 #define Stack (1<<13) /* Stack instruction (push/pop) */
76 #define Group (1<<14) /* Bits 3:5 of modrm byte extend opcode */
77 #define GroupDual (1<<15) /* Alternate decoding of mod == 3 */
78 /* Misc flags */
79 #define VendorSpecific (1<<22) /* Vendor specific instruction */
80 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
81 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */
82 #define Undefined (1<<25) /* No Such Instruction */
83 #define Lock (1<<26) /* lock prefix is allowed for the instruction */
84 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
85 #define No64 (1<<28)
86 /* Source 2 operand type */
87 #define Src2None (0<<29)
88 #define Src2CL (1<<29)
89 #define Src2ImmByte (2<<29)
90 #define Src2One (3<<29)
91 #define Src2Imm (4<<29)
92 #define Src2Mask (7<<29)
93
94 #define X2(x...) x, x
95 #define X3(x...) X2(x), x
96 #define X4(x...) X2(x), X2(x)
97 #define X5(x...) X4(x), x
98 #define X6(x...) X4(x), X2(x)
99 #define X7(x...) X4(x), X3(x)
100 #define X8(x...) X4(x), X4(x)
101 #define X16(x...) X8(x), X8(x)
102
103 struct opcode {
104 u32 flags;
105 union {
106 int (*execute)(struct x86_emulate_ctxt *ctxt);
107 struct opcode *group;
108 struct group_dual *gdual;
109 } u;
110 };
111
112 struct group_dual {
113 struct opcode mod012[8];
114 struct opcode mod3[8];
115 };
116
117 /* EFLAGS bit definitions. */
118 #define EFLG_ID (1<<21)
119 #define EFLG_VIP (1<<20)
120 #define EFLG_VIF (1<<19)
121 #define EFLG_AC (1<<18)
122 #define EFLG_VM (1<<17)
123 #define EFLG_RF (1<<16)
124 #define EFLG_IOPL (3<<12)
125 #define EFLG_NT (1<<14)
126 #define EFLG_OF (1<<11)
127 #define EFLG_DF (1<<10)
128 #define EFLG_IF (1<<9)
129 #define EFLG_TF (1<<8)
130 #define EFLG_SF (1<<7)
131 #define EFLG_ZF (1<<6)
132 #define EFLG_AF (1<<4)
133 #define EFLG_PF (1<<2)
134 #define EFLG_CF (1<<0)
135
136 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a
137 #define EFLG_RESERVED_ONE_MASK 2
138
139 /*
140 * Instruction emulation:
141 * Most instructions are emulated directly via a fragment of inline assembly
142 * code. This allows us to save/restore EFLAGS and thus very easily pick up
143 * any modified flags.
144 */
145
146 #if defined(CONFIG_X86_64)
147 #define _LO32 "k" /* force 32-bit operand */
148 #define _STK "%%rsp" /* stack pointer */
149 #elif defined(__i386__)
150 #define _LO32 "" /* force 32-bit operand */
151 #define _STK "%%esp" /* stack pointer */
152 #endif
153
154 /*
155 * These EFLAGS bits are restored from saved value during emulation, and
156 * any changes are written back to the saved value after emulation.
157 */
158 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
159
160 /* Before executing instruction: restore necessary bits in EFLAGS. */
161 #define _PRE_EFLAGS(_sav, _msk, _tmp) \
162 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \
163 "movl %"_sav",%"_LO32 _tmp"; " \
164 "push %"_tmp"; " \
165 "push %"_tmp"; " \
166 "movl %"_msk",%"_LO32 _tmp"; " \
167 "andl %"_LO32 _tmp",("_STK"); " \
168 "pushf; " \
169 "notl %"_LO32 _tmp"; " \
170 "andl %"_LO32 _tmp",("_STK"); " \
171 "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \
172 "pop %"_tmp"; " \
173 "orl %"_LO32 _tmp",("_STK"); " \
174 "popf; " \
175 "pop %"_sav"; "
176
177 /* After executing instruction: write-back necessary bits in EFLAGS. */
178 #define _POST_EFLAGS(_sav, _msk, _tmp) \
179 /* _sav |= EFLAGS & _msk; */ \
180 "pushf; " \
181 "pop %"_tmp"; " \
182 "andl %"_msk",%"_LO32 _tmp"; " \
183 "orl %"_LO32 _tmp",%"_sav"; "
184
185 #ifdef CONFIG_X86_64
186 #define ON64(x) x
187 #else
188 #define ON64(x)
189 #endif
190
191 #define ____emulate_2op(_op, _src, _dst, _eflags, _x, _y, _suffix, _dsttype) \
192 do { \
193 __asm__ __volatile__ ( \
194 _PRE_EFLAGS("0", "4", "2") \
195 _op _suffix " %"_x"3,%1; " \
196 _POST_EFLAGS("0", "4", "2") \
197 : "=m" (_eflags), "+q" (*(_dsttype*)&(_dst).val),\
198 "=&r" (_tmp) \
199 : _y ((_src).val), "i" (EFLAGS_MASK)); \
200 } while (0)
201
202
203 /* Raw emulation: instruction has two explicit operands. */
204 #define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \
205 do { \
206 unsigned long _tmp; \
207 \
208 switch ((_dst).bytes) { \
209 case 2: \
210 ____emulate_2op(_op,_src,_dst,_eflags,_wx,_wy,"w",u16);\
211 break; \
212 case 4: \
213 ____emulate_2op(_op,_src,_dst,_eflags,_lx,_ly,"l",u32);\
214 break; \
215 case 8: \
216 ON64(____emulate_2op(_op,_src,_dst,_eflags,_qx,_qy,"q",u64)); \
217 break; \
218 } \
219 } while (0)
220
221 #define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \
222 do { \
223 unsigned long _tmp; \
224 switch ((_dst).bytes) { \
225 case 1: \
226 ____emulate_2op(_op,_src,_dst,_eflags,_bx,_by,"b",u8); \
227 break; \
228 default: \
229 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
230 _wx, _wy, _lx, _ly, _qx, _qy); \
231 break; \
232 } \
233 } while (0)
234
235 /* Source operand is byte-sized and may be restricted to just %cl. */
236 #define emulate_2op_SrcB(_op, _src, _dst, _eflags) \
237 __emulate_2op(_op, _src, _dst, _eflags, \
238 "b", "c", "b", "c", "b", "c", "b", "c")
239
240 /* Source operand is byte, word, long or quad sized. */
241 #define emulate_2op_SrcV(_op, _src, _dst, _eflags) \
242 __emulate_2op(_op, _src, _dst, _eflags, \
243 "b", "q", "w", "r", _LO32, "r", "", "r")
244
245 /* Source operand is word, long or quad sized. */
246 #define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \
247 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
248 "w", "r", _LO32, "r", "", "r")
249
250 /* Instruction has three operands and one operand is stored in ECX register */
251 #define __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, _suffix, _type) \
252 do { \
253 unsigned long _tmp; \
254 _type _clv = (_cl).val; \
255 _type _srcv = (_src).val; \
256 _type _dstv = (_dst).val; \
257 \
258 __asm__ __volatile__ ( \
259 _PRE_EFLAGS("0", "5", "2") \
260 _op _suffix " %4,%1 \n" \
261 _POST_EFLAGS("0", "5", "2") \
262 : "=m" (_eflags), "+r" (_dstv), "=&r" (_tmp) \
263 : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \
264 ); \
265 \
266 (_cl).val = (unsigned long) _clv; \
267 (_src).val = (unsigned long) _srcv; \
268 (_dst).val = (unsigned long) _dstv; \
269 } while (0)
270
271 #define emulate_2op_cl(_op, _cl, _src, _dst, _eflags) \
272 do { \
273 switch ((_dst).bytes) { \
274 case 2: \
275 __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \
276 "w", unsigned short); \
277 break; \
278 case 4: \
279 __emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \
280 "l", unsigned int); \
281 break; \
282 case 8: \
283 ON64(__emulate_2op_cl(_op, _cl, _src, _dst, _eflags, \
284 "q", unsigned long)); \
285 break; \
286 } \
287 } while (0)
288
289 #define __emulate_1op(_op, _dst, _eflags, _suffix) \
290 do { \
291 unsigned long _tmp; \
292 \
293 __asm__ __volatile__ ( \
294 _PRE_EFLAGS("0", "3", "2") \
295 _op _suffix " %1; " \
296 _POST_EFLAGS("0", "3", "2") \
297 : "=m" (_eflags), "+m" ((_dst).val), \
298 "=&r" (_tmp) \
299 : "i" (EFLAGS_MASK)); \
300 } while (0)
301
302 /* Instruction has only one explicit operand (no source operand). */
303 #define emulate_1op(_op, _dst, _eflags) \
304 do { \
305 switch ((_dst).bytes) { \
306 case 1: __emulate_1op(_op, _dst, _eflags, "b"); break; \
307 case 2: __emulate_1op(_op, _dst, _eflags, "w"); break; \
308 case 4: __emulate_1op(_op, _dst, _eflags, "l"); break; \
309 case 8: ON64(__emulate_1op(_op, _dst, _eflags, "q")); break; \
310 } \
311 } while (0)
312
313 #define __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags, _suffix) \
314 do { \
315 unsigned long _tmp; \
316 \
317 __asm__ __volatile__ ( \
318 _PRE_EFLAGS("0", "4", "1") \
319 _op _suffix " %5; " \
320 _POST_EFLAGS("0", "4", "1") \
321 : "=m" (_eflags), "=&r" (_tmp), \
322 "+a" (_rax), "+d" (_rdx) \
323 : "i" (EFLAGS_MASK), "m" ((_src).val), \
324 "a" (_rax), "d" (_rdx)); \
325 } while (0)
326
327 #define __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, _eflags, _suffix, _ex) \
328 do { \
329 unsigned long _tmp; \
330 \
331 __asm__ __volatile__ ( \
332 _PRE_EFLAGS("0", "5", "1") \
333 "1: \n\t" \
334 _op _suffix " %6; " \
335 "2: \n\t" \
336 _POST_EFLAGS("0", "5", "1") \
337 ".pushsection .fixup,\"ax\" \n\t" \
338 "3: movb $1, %4 \n\t" \
339 "jmp 2b \n\t" \
340 ".popsection \n\t" \
341 _ASM_EXTABLE(1b, 3b) \
342 : "=m" (_eflags), "=&r" (_tmp), \
343 "+a" (_rax), "+d" (_rdx), "+qm"(_ex) \
344 : "i" (EFLAGS_MASK), "m" ((_src).val), \
345 "a" (_rax), "d" (_rdx)); \
346 } while (0)
347
348 /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */
349 #define emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags) \
350 do { \
351 switch((_src).bytes) { \
352 case 1: __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags, "b"); break; \
353 case 2: __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags, "w"); break; \
354 case 4: __emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags, "l"); break; \
355 case 8: ON64(__emulate_1op_rax_rdx(_op, _src, _rax, _rdx, _eflags, "q")); break; \
356 } \
357 } while (0)
358
359 #define emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, _eflags, _ex) \
360 do { \
361 switch((_src).bytes) { \
362 case 1: \
363 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
364 _eflags, "b", _ex); \
365 break; \
366 case 2: \
367 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
368 _eflags, "w", _ex); \
369 break; \
370 case 4: \
371 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
372 _eflags, "l", _ex); \
373 break; \
374 case 8: ON64( \
375 __emulate_1op_rax_rdx_ex(_op, _src, _rax, _rdx, \
376 _eflags, "q", _ex)); \
377 break; \
378 } \
379 } while (0)
380
381 /* Fetch next part of the instruction being emulated. */
382 #define insn_fetch(_type, _size, _eip) \
383 ({ unsigned long _x; \
384 rc = do_insn_fetch(ctxt, ops, (_eip), &_x, (_size)); \
385 if (rc != X86EMUL_CONTINUE) \
386 goto done; \
387 (_eip) += (_size); \
388 (_type)_x; \
389 })
390
391 #define insn_fetch_arr(_arr, _size, _eip) \
392 ({ rc = do_insn_fetch(ctxt, ops, (_eip), _arr, (_size)); \
393 if (rc != X86EMUL_CONTINUE) \
394 goto done; \
395 (_eip) += (_size); \
396 })
397
398 static inline unsigned long ad_mask(struct decode_cache *c)
399 {
400 return (1UL << (c->ad_bytes << 3)) - 1;
401 }
402
403 /* Access/update address held in a register, based on addressing mode. */
404 static inline unsigned long
405 address_mask(struct decode_cache *c, unsigned long reg)
406 {
407 if (c->ad_bytes == sizeof(unsigned long))
408 return reg;
409 else
410 return reg & ad_mask(c);
411 }
412
413 static inline unsigned long
414 register_address(struct decode_cache *c, unsigned long reg)
415 {
416 return address_mask(c, reg);
417 }
418
419 static inline void
420 register_address_increment(struct decode_cache *c, unsigned long *reg, int inc)
421 {
422 if (c->ad_bytes == sizeof(unsigned long))
423 *reg += inc;
424 else
425 *reg = (*reg & ~ad_mask(c)) | ((*reg + inc) & ad_mask(c));
426 }
427
428 static inline void jmp_rel(struct decode_cache *c, int rel)
429 {
430 register_address_increment(c, &c->eip, rel);
431 }
432
433 static void set_seg_override(struct decode_cache *c, int seg)
434 {
435 c->has_seg_override = true;
436 c->seg_override = seg;
437 }
438
439 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt,
440 struct x86_emulate_ops *ops, int seg)
441 {
442 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
443 return 0;
444
445 return ops->get_cached_segment_base(seg, ctxt->vcpu);
446 }
447
448 static unsigned seg_override(struct x86_emulate_ctxt *ctxt,
449 struct x86_emulate_ops *ops,
450 struct decode_cache *c)
451 {
452 if (!c->has_seg_override)
453 return 0;
454
455 return c->seg_override;
456 }
457
458 static ulong linear(struct x86_emulate_ctxt *ctxt,
459 struct segmented_address addr)
460 {
461 struct decode_cache *c = &ctxt->decode;
462 ulong la;
463
464 la = seg_base(ctxt, ctxt->ops, addr.seg) + addr.ea;
465 if (c->ad_bytes != 8)
466 la &= (u32)-1;
467 return la;
468 }
469
470 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
471 u32 error, bool valid)
472 {
473 ctxt->exception.vector = vec;
474 ctxt->exception.error_code = error;
475 ctxt->exception.error_code_valid = valid;
476 return X86EMUL_PROPAGATE_FAULT;
477 }
478
479 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
480 {
481 return emulate_exception(ctxt, GP_VECTOR, err, true);
482 }
483
484 static int emulate_ud(struct x86_emulate_ctxt *ctxt)
485 {
486 return emulate_exception(ctxt, UD_VECTOR, 0, false);
487 }
488
489 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)
490 {
491 return emulate_exception(ctxt, TS_VECTOR, err, true);
492 }
493
494 static int emulate_de(struct x86_emulate_ctxt *ctxt)
495 {
496 return emulate_exception(ctxt, DE_VECTOR, 0, false);
497 }
498
499 static int do_fetch_insn_byte(struct x86_emulate_ctxt *ctxt,
500 struct x86_emulate_ops *ops,
501 unsigned long eip, u8 *dest)
502 {
503 struct fetch_cache *fc = &ctxt->decode.fetch;
504 int rc;
505 int size, cur_size;
506
507 if (eip == fc->end) {
508 cur_size = fc->end - fc->start;
509 size = min(15UL - cur_size, PAGE_SIZE - offset_in_page(eip));
510 rc = ops->fetch(ctxt->cs_base + eip, fc->data + cur_size,
511 size, ctxt->vcpu, &ctxt->exception);
512 if (rc != X86EMUL_CONTINUE)
513 return rc;
514 fc->end += size;
515 }
516 *dest = fc->data[eip - fc->start];
517 return X86EMUL_CONTINUE;
518 }
519
520 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt,
521 struct x86_emulate_ops *ops,
522 unsigned long eip, void *dest, unsigned size)
523 {
524 int rc;
525
526 /* x86 instructions are limited to 15 bytes. */
527 if (eip + size - ctxt->eip > 15)
528 return X86EMUL_UNHANDLEABLE;
529 while (size--) {
530 rc = do_fetch_insn_byte(ctxt, ops, eip++, dest++);
531 if (rc != X86EMUL_CONTINUE)
532 return rc;
533 }
534 return X86EMUL_CONTINUE;
535 }
536
537 /*
538 * Given the 'reg' portion of a ModRM byte, and a register block, return a
539 * pointer into the block that addresses the relevant register.
540 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
541 */
542 static void *decode_register(u8 modrm_reg, unsigned long *regs,
543 int highbyte_regs)
544 {
545 void *p;
546
547 p = &regs[modrm_reg];
548 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
549 p = (unsigned char *)&regs[modrm_reg & 3] + 1;
550 return p;
551 }
552
553 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
554 struct x86_emulate_ops *ops,
555 struct segmented_address addr,
556 u16 *size, unsigned long *address, int op_bytes)
557 {
558 int rc;
559
560 if (op_bytes == 2)
561 op_bytes = 3;
562 *address = 0;
563 rc = ops->read_std(linear(ctxt, addr), (unsigned long *)size, 2,
564 ctxt->vcpu, &ctxt->exception);
565 if (rc != X86EMUL_CONTINUE)
566 return rc;
567 addr.ea += 2;
568 rc = ops->read_std(linear(ctxt, addr), address, op_bytes,
569 ctxt->vcpu, &ctxt->exception);
570 return rc;
571 }
572
573 static int test_cc(unsigned int condition, unsigned int flags)
574 {
575 int rc = 0;
576
577 switch ((condition & 15) >> 1) {
578 case 0: /* o */
579 rc |= (flags & EFLG_OF);
580 break;
581 case 1: /* b/c/nae */
582 rc |= (flags & EFLG_CF);
583 break;
584 case 2: /* z/e */
585 rc |= (flags & EFLG_ZF);
586 break;
587 case 3: /* be/na */
588 rc |= (flags & (EFLG_CF|EFLG_ZF));
589 break;
590 case 4: /* s */
591 rc |= (flags & EFLG_SF);
592 break;
593 case 5: /* p/pe */
594 rc |= (flags & EFLG_PF);
595 break;
596 case 7: /* le/ng */
597 rc |= (flags & EFLG_ZF);
598 /* fall through */
599 case 6: /* l/nge */
600 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
601 break;
602 }
603
604 /* Odd condition identifiers (lsb == 1) have inverted sense. */
605 return (!!rc ^ (condition & 1));
606 }
607
608 static void fetch_register_operand(struct operand *op)
609 {
610 switch (op->bytes) {
611 case 1:
612 op->val = *(u8 *)op->addr.reg;
613 break;
614 case 2:
615 op->val = *(u16 *)op->addr.reg;
616 break;
617 case 4:
618 op->val = *(u32 *)op->addr.reg;
619 break;
620 case 8:
621 op->val = *(u64 *)op->addr.reg;
622 break;
623 }
624 }
625
626 static void decode_register_operand(struct operand *op,
627 struct decode_cache *c,
628 int inhibit_bytereg)
629 {
630 unsigned reg = c->modrm_reg;
631 int highbyte_regs = c->rex_prefix == 0;
632
633 if (!(c->d & ModRM))
634 reg = (c->b & 7) | ((c->rex_prefix & 1) << 3);
635 op->type = OP_REG;
636 if ((c->d & ByteOp) && !inhibit_bytereg) {
637 op->addr.reg = decode_register(reg, c->regs, highbyte_regs);
638 op->bytes = 1;
639 } else {
640 op->addr.reg = decode_register(reg, c->regs, 0);
641 op->bytes = c->op_bytes;
642 }
643 fetch_register_operand(op);
644 op->orig_val = op->val;
645 }
646
647 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
648 struct x86_emulate_ops *ops,
649 struct operand *op)
650 {
651 struct decode_cache *c = &ctxt->decode;
652 u8 sib;
653 int index_reg = 0, base_reg = 0, scale;
654 int rc = X86EMUL_CONTINUE;
655 ulong modrm_ea = 0;
656
657 if (c->rex_prefix) {
658 c->modrm_reg = (c->rex_prefix & 4) << 1; /* REX.R */
659 index_reg = (c->rex_prefix & 2) << 2; /* REX.X */
660 c->modrm_rm = base_reg = (c->rex_prefix & 1) << 3; /* REG.B */
661 }
662
663 c->modrm = insn_fetch(u8, 1, c->eip);
664 c->modrm_mod |= (c->modrm & 0xc0) >> 6;
665 c->modrm_reg |= (c->modrm & 0x38) >> 3;
666 c->modrm_rm |= (c->modrm & 0x07);
667 c->modrm_seg = VCPU_SREG_DS;
668
669 if (c->modrm_mod == 3) {
670 op->type = OP_REG;
671 op->bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
672 op->addr.reg = decode_register(c->modrm_rm,
673 c->regs, c->d & ByteOp);
674 fetch_register_operand(op);
675 return rc;
676 }
677
678 op->type = OP_MEM;
679
680 if (c->ad_bytes == 2) {
681 unsigned bx = c->regs[VCPU_REGS_RBX];
682 unsigned bp = c->regs[VCPU_REGS_RBP];
683 unsigned si = c->regs[VCPU_REGS_RSI];
684 unsigned di = c->regs[VCPU_REGS_RDI];
685
686 /* 16-bit ModR/M decode. */
687 switch (c->modrm_mod) {
688 case 0:
689 if (c->modrm_rm == 6)
690 modrm_ea += insn_fetch(u16, 2, c->eip);
691 break;
692 case 1:
693 modrm_ea += insn_fetch(s8, 1, c->eip);
694 break;
695 case 2:
696 modrm_ea += insn_fetch(u16, 2, c->eip);
697 break;
698 }
699 switch (c->modrm_rm) {
700 case 0:
701 modrm_ea += bx + si;
702 break;
703 case 1:
704 modrm_ea += bx + di;
705 break;
706 case 2:
707 modrm_ea += bp + si;
708 break;
709 case 3:
710 modrm_ea += bp + di;
711 break;
712 case 4:
713 modrm_ea += si;
714 break;
715 case 5:
716 modrm_ea += di;
717 break;
718 case 6:
719 if (c->modrm_mod != 0)
720 modrm_ea += bp;
721 break;
722 case 7:
723 modrm_ea += bx;
724 break;
725 }
726 if (c->modrm_rm == 2 || c->modrm_rm == 3 ||
727 (c->modrm_rm == 6 && c->modrm_mod != 0))
728 c->modrm_seg = VCPU_SREG_SS;
729 modrm_ea = (u16)modrm_ea;
730 } else {
731 /* 32/64-bit ModR/M decode. */
732 if ((c->modrm_rm & 7) == 4) {
733 sib = insn_fetch(u8, 1, c->eip);
734 index_reg |= (sib >> 3) & 7;
735 base_reg |= sib & 7;
736 scale = sib >> 6;
737
738 if ((base_reg & 7) == 5 && c->modrm_mod == 0)
739 modrm_ea += insn_fetch(s32, 4, c->eip);
740 else
741 modrm_ea += c->regs[base_reg];
742 if (index_reg != 4)
743 modrm_ea += c->regs[index_reg] << scale;
744 } else if ((c->modrm_rm & 7) == 5 && c->modrm_mod == 0) {
745 if (ctxt->mode == X86EMUL_MODE_PROT64)
746 c->rip_relative = 1;
747 } else
748 modrm_ea += c->regs[c->modrm_rm];
749 switch (c->modrm_mod) {
750 case 0:
751 if (c->modrm_rm == 5)
752 modrm_ea += insn_fetch(s32, 4, c->eip);
753 break;
754 case 1:
755 modrm_ea += insn_fetch(s8, 1, c->eip);
756 break;
757 case 2:
758 modrm_ea += insn_fetch(s32, 4, c->eip);
759 break;
760 }
761 }
762 op->addr.mem.ea = modrm_ea;
763 done:
764 return rc;
765 }
766
767 static int decode_abs(struct x86_emulate_ctxt *ctxt,
768 struct x86_emulate_ops *ops,
769 struct operand *op)
770 {
771 struct decode_cache *c = &ctxt->decode;
772 int rc = X86EMUL_CONTINUE;
773
774 op->type = OP_MEM;
775 switch (c->ad_bytes) {
776 case 2:
777 op->addr.mem.ea = insn_fetch(u16, 2, c->eip);
778 break;
779 case 4:
780 op->addr.mem.ea = insn_fetch(u32, 4, c->eip);
781 break;
782 case 8:
783 op->addr.mem.ea = insn_fetch(u64, 8, c->eip);
784 break;
785 }
786 done:
787 return rc;
788 }
789
790 static void fetch_bit_operand(struct decode_cache *c)
791 {
792 long sv = 0, mask;
793
794 if (c->dst.type == OP_MEM && c->src.type == OP_REG) {
795 mask = ~(c->dst.bytes * 8 - 1);
796
797 if (c->src.bytes == 2)
798 sv = (s16)c->src.val & (s16)mask;
799 else if (c->src.bytes == 4)
800 sv = (s32)c->src.val & (s32)mask;
801
802 c->dst.addr.mem.ea += (sv >> 3);
803 }
804
805 /* only subword offset */
806 c->src.val &= (c->dst.bytes << 3) - 1;
807 }
808
809 static int read_emulated(struct x86_emulate_ctxt *ctxt,
810 struct x86_emulate_ops *ops,
811 unsigned long addr, void *dest, unsigned size)
812 {
813 int rc;
814 struct read_cache *mc = &ctxt->decode.mem_read;
815
816 while (size) {
817 int n = min(size, 8u);
818 size -= n;
819 if (mc->pos < mc->end)
820 goto read_cached;
821
822 rc = ops->read_emulated(addr, mc->data + mc->end, n,
823 &ctxt->exception, ctxt->vcpu);
824 if (rc != X86EMUL_CONTINUE)
825 return rc;
826 mc->end += n;
827
828 read_cached:
829 memcpy(dest, mc->data + mc->pos, n);
830 mc->pos += n;
831 dest += n;
832 addr += n;
833 }
834 return X86EMUL_CONTINUE;
835 }
836
837 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
838 struct x86_emulate_ops *ops,
839 unsigned int size, unsigned short port,
840 void *dest)
841 {
842 struct read_cache *rc = &ctxt->decode.io_read;
843
844 if (rc->pos == rc->end) { /* refill pio read ahead */
845 struct decode_cache *c = &ctxt->decode;
846 unsigned int in_page, n;
847 unsigned int count = c->rep_prefix ?
848 address_mask(c, c->regs[VCPU_REGS_RCX]) : 1;
849 in_page = (ctxt->eflags & EFLG_DF) ?
850 offset_in_page(c->regs[VCPU_REGS_RDI]) :
851 PAGE_SIZE - offset_in_page(c->regs[VCPU_REGS_RDI]);
852 n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size,
853 count);
854 if (n == 0)
855 n = 1;
856 rc->pos = rc->end = 0;
857 if (!ops->pio_in_emulated(size, port, rc->data, n, ctxt->vcpu))
858 return 0;
859 rc->end = n * size;
860 }
861
862 memcpy(dest, rc->data + rc->pos, size);
863 rc->pos += size;
864 return 1;
865 }
866
867 static u32 desc_limit_scaled(struct desc_struct *desc)
868 {
869 u32 limit = get_desc_limit(desc);
870
871 return desc->g ? (limit << 12) | 0xfff : limit;
872 }
873
874 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
875 struct x86_emulate_ops *ops,
876 u16 selector, struct desc_ptr *dt)
877 {
878 if (selector & 1 << 2) {
879 struct desc_struct desc;
880 memset (dt, 0, sizeof *dt);
881 if (!ops->get_cached_descriptor(&desc, NULL, VCPU_SREG_LDTR,
882 ctxt->vcpu))
883 return;
884
885 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
886 dt->address = get_desc_base(&desc);
887 } else
888 ops->get_gdt(dt, ctxt->vcpu);
889 }
890
891 /* allowed just for 8 bytes segments */
892 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
893 struct x86_emulate_ops *ops,
894 u16 selector, struct desc_struct *desc)
895 {
896 struct desc_ptr dt;
897 u16 index = selector >> 3;
898 int ret;
899 ulong addr;
900
901 get_descriptor_table_ptr(ctxt, ops, selector, &dt);
902
903 if (dt.size < index * 8 + 7)
904 return emulate_gp(ctxt, selector & 0xfffc);
905 addr = dt.address + index * 8;
906 ret = ops->read_std(addr, desc, sizeof *desc, ctxt->vcpu,
907 &ctxt->exception);
908
909 return ret;
910 }
911
912 /* allowed just for 8 bytes segments */
913 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
914 struct x86_emulate_ops *ops,
915 u16 selector, struct desc_struct *desc)
916 {
917 struct desc_ptr dt;
918 u16 index = selector >> 3;
919 ulong addr;
920 int ret;
921
922 get_descriptor_table_ptr(ctxt, ops, selector, &dt);
923
924 if (dt.size < index * 8 + 7)
925 return emulate_gp(ctxt, selector & 0xfffc);
926
927 addr = dt.address + index * 8;
928 ret = ops->write_std(addr, desc, sizeof *desc, ctxt->vcpu,
929 &ctxt->exception);
930
931 return ret;
932 }
933
934 /* Does not support long mode */
935 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
936 struct x86_emulate_ops *ops,
937 u16 selector, int seg)
938 {
939 struct desc_struct seg_desc;
940 u8 dpl, rpl, cpl;
941 unsigned err_vec = GP_VECTOR;
942 u32 err_code = 0;
943 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
944 int ret;
945
946 memset(&seg_desc, 0, sizeof seg_desc);
947
948 if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86)
949 || ctxt->mode == X86EMUL_MODE_REAL) {
950 /* set real mode segment descriptor */
951 set_desc_base(&seg_desc, selector << 4);
952 set_desc_limit(&seg_desc, 0xffff);
953 seg_desc.type = 3;
954 seg_desc.p = 1;
955 seg_desc.s = 1;
956 goto load;
957 }
958
959 /* NULL selector is not valid for TR, CS and SS */
960 if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR)
961 && null_selector)
962 goto exception;
963
964 /* TR should be in GDT only */
965 if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
966 goto exception;
967
968 if (null_selector) /* for NULL selector skip all following checks */
969 goto load;
970
971 ret = read_segment_descriptor(ctxt, ops, selector, &seg_desc);
972 if (ret != X86EMUL_CONTINUE)
973 return ret;
974
975 err_code = selector & 0xfffc;
976 err_vec = GP_VECTOR;
977
978 /* can't load system descriptor into segment selecor */
979 if (seg <= VCPU_SREG_GS && !seg_desc.s)
980 goto exception;
981
982 if (!seg_desc.p) {
983 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
984 goto exception;
985 }
986
987 rpl = selector & 3;
988 dpl = seg_desc.dpl;
989 cpl = ops->cpl(ctxt->vcpu);
990
991 switch (seg) {
992 case VCPU_SREG_SS:
993 /*
994 * segment is not a writable data segment or segment
995 * selector's RPL != CPL or segment selector's RPL != CPL
996 */
997 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
998 goto exception;
999 break;
1000 case VCPU_SREG_CS:
1001 if (!(seg_desc.type & 8))
1002 goto exception;
1003
1004 if (seg_desc.type & 4) {
1005 /* conforming */
1006 if (dpl > cpl)
1007 goto exception;
1008 } else {
1009 /* nonconforming */
1010 if (rpl > cpl || dpl != cpl)
1011 goto exception;
1012 }
1013 /* CS(RPL) <- CPL */
1014 selector = (selector & 0xfffc) | cpl;
1015 break;
1016 case VCPU_SREG_TR:
1017 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1018 goto exception;
1019 break;
1020 case VCPU_SREG_LDTR:
1021 if (seg_desc.s || seg_desc.type != 2)
1022 goto exception;
1023 break;
1024 default: /* DS, ES, FS, or GS */
1025 /*
1026 * segment is not a data or readable code segment or
1027 * ((segment is a data or nonconforming code segment)
1028 * and (both RPL and CPL > DPL))
1029 */
1030 if ((seg_desc.type & 0xa) == 0x8 ||
1031 (((seg_desc.type & 0xc) != 0xc) &&
1032 (rpl > dpl && cpl > dpl)))
1033 goto exception;
1034 break;
1035 }
1036
1037 if (seg_desc.s) {
1038 /* mark segment as accessed */
1039 seg_desc.type |= 1;
1040 ret = write_segment_descriptor(ctxt, ops, selector, &seg_desc);
1041 if (ret != X86EMUL_CONTINUE)
1042 return ret;
1043 }
1044 load:
1045 ops->set_segment_selector(selector, seg, ctxt->vcpu);
1046 ops->set_cached_descriptor(&seg_desc, 0, seg, ctxt->vcpu);
1047 return X86EMUL_CONTINUE;
1048 exception:
1049 emulate_exception(ctxt, err_vec, err_code, true);
1050 return X86EMUL_PROPAGATE_FAULT;
1051 }
1052
1053 static void write_register_operand(struct operand *op)
1054 {
1055 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
1056 switch (op->bytes) {
1057 case 1:
1058 *(u8 *)op->addr.reg = (u8)op->val;
1059 break;
1060 case 2:
1061 *(u16 *)op->addr.reg = (u16)op->val;
1062 break;
1063 case 4:
1064 *op->addr.reg = (u32)op->val;
1065 break; /* 64b: zero-extend */
1066 case 8:
1067 *op->addr.reg = op->val;
1068 break;
1069 }
1070 }
1071
1072 static inline int writeback(struct x86_emulate_ctxt *ctxt,
1073 struct x86_emulate_ops *ops)
1074 {
1075 int rc;
1076 struct decode_cache *c = &ctxt->decode;
1077
1078 switch (c->dst.type) {
1079 case OP_REG:
1080 write_register_operand(&c->dst);
1081 break;
1082 case OP_MEM:
1083 if (c->lock_prefix)
1084 rc = ops->cmpxchg_emulated(
1085 linear(ctxt, c->dst.addr.mem),
1086 &c->dst.orig_val,
1087 &c->dst.val,
1088 c->dst.bytes,
1089 &ctxt->exception,
1090 ctxt->vcpu);
1091 else
1092 rc = ops->write_emulated(
1093 linear(ctxt, c->dst.addr.mem),
1094 &c->dst.val,
1095 c->dst.bytes,
1096 &ctxt->exception,
1097 ctxt->vcpu);
1098 if (rc != X86EMUL_CONTINUE)
1099 return rc;
1100 break;
1101 case OP_NONE:
1102 /* no writeback */
1103 break;
1104 default:
1105 break;
1106 }
1107 return X86EMUL_CONTINUE;
1108 }
1109
1110 static inline void emulate_push(struct x86_emulate_ctxt *ctxt,
1111 struct x86_emulate_ops *ops)
1112 {
1113 struct decode_cache *c = &ctxt->decode;
1114
1115 c->dst.type = OP_MEM;
1116 c->dst.bytes = c->op_bytes;
1117 c->dst.val = c->src.val;
1118 register_address_increment(c, &c->regs[VCPU_REGS_RSP], -c->op_bytes);
1119 c->dst.addr.mem.ea = register_address(c, c->regs[VCPU_REGS_RSP]);
1120 c->dst.addr.mem.seg = VCPU_SREG_SS;
1121 }
1122
1123 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1124 struct x86_emulate_ops *ops,
1125 void *dest, int len)
1126 {
1127 struct decode_cache *c = &ctxt->decode;
1128 int rc;
1129 struct segmented_address addr;
1130
1131 addr.ea = register_address(c, c->regs[VCPU_REGS_RSP]);
1132 addr.seg = VCPU_SREG_SS;
1133 rc = read_emulated(ctxt, ops, linear(ctxt, addr), dest, len);
1134 if (rc != X86EMUL_CONTINUE)
1135 return rc;
1136
1137 register_address_increment(c, &c->regs[VCPU_REGS_RSP], len);
1138 return rc;
1139 }
1140
1141 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1142 struct x86_emulate_ops *ops,
1143 void *dest, int len)
1144 {
1145 int rc;
1146 unsigned long val, change_mask;
1147 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1148 int cpl = ops->cpl(ctxt->vcpu);
1149
1150 rc = emulate_pop(ctxt, ops, &val, len);
1151 if (rc != X86EMUL_CONTINUE)
1152 return rc;
1153
1154 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
1155 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID;
1156
1157 switch(ctxt->mode) {
1158 case X86EMUL_MODE_PROT64:
1159 case X86EMUL_MODE_PROT32:
1160 case X86EMUL_MODE_PROT16:
1161 if (cpl == 0)
1162 change_mask |= EFLG_IOPL;
1163 if (cpl <= iopl)
1164 change_mask |= EFLG_IF;
1165 break;
1166 case X86EMUL_MODE_VM86:
1167 if (iopl < 3)
1168 return emulate_gp(ctxt, 0);
1169 change_mask |= EFLG_IF;
1170 break;
1171 default: /* real mode */
1172 change_mask |= (EFLG_IOPL | EFLG_IF);
1173 break;
1174 }
1175
1176 *(unsigned long *)dest =
1177 (ctxt->eflags & ~change_mask) | (val & change_mask);
1178
1179 return rc;
1180 }
1181
1182 static void emulate_push_sreg(struct x86_emulate_ctxt *ctxt,
1183 struct x86_emulate_ops *ops, int seg)
1184 {
1185 struct decode_cache *c = &ctxt->decode;
1186
1187 c->src.val = ops->get_segment_selector(seg, ctxt->vcpu);
1188
1189 emulate_push(ctxt, ops);
1190 }
1191
1192 static int emulate_pop_sreg(struct x86_emulate_ctxt *ctxt,
1193 struct x86_emulate_ops *ops, int seg)
1194 {
1195 struct decode_cache *c = &ctxt->decode;
1196 unsigned long selector;
1197 int rc;
1198
1199 rc = emulate_pop(ctxt, ops, &selector, c->op_bytes);
1200 if (rc != X86EMUL_CONTINUE)
1201 return rc;
1202
1203 rc = load_segment_descriptor(ctxt, ops, (u16)selector, seg);
1204 return rc;
1205 }
1206
1207 static int emulate_pusha(struct x86_emulate_ctxt *ctxt,
1208 struct x86_emulate_ops *ops)
1209 {
1210 struct decode_cache *c = &ctxt->decode;
1211 unsigned long old_esp = c->regs[VCPU_REGS_RSP];
1212 int rc = X86EMUL_CONTINUE;
1213 int reg = VCPU_REGS_RAX;
1214
1215 while (reg <= VCPU_REGS_RDI) {
1216 (reg == VCPU_REGS_RSP) ?
1217 (c->src.val = old_esp) : (c->src.val = c->regs[reg]);
1218
1219 emulate_push(ctxt, ops);
1220
1221 rc = writeback(ctxt, ops);
1222 if (rc != X86EMUL_CONTINUE)
1223 return rc;
1224
1225 ++reg;
1226 }
1227
1228 /* Disable writeback. */
1229 c->dst.type = OP_NONE;
1230
1231 return rc;
1232 }
1233
1234 static int emulate_popa(struct x86_emulate_ctxt *ctxt,
1235 struct x86_emulate_ops *ops)
1236 {
1237 struct decode_cache *c = &ctxt->decode;
1238 int rc = X86EMUL_CONTINUE;
1239 int reg = VCPU_REGS_RDI;
1240
1241 while (reg >= VCPU_REGS_RAX) {
1242 if (reg == VCPU_REGS_RSP) {
1243 register_address_increment(c, &c->regs[VCPU_REGS_RSP],
1244 c->op_bytes);
1245 --reg;
1246 }
1247
1248 rc = emulate_pop(ctxt, ops, &c->regs[reg], c->op_bytes);
1249 if (rc != X86EMUL_CONTINUE)
1250 break;
1251 --reg;
1252 }
1253 return rc;
1254 }
1255
1256 int emulate_int_real(struct x86_emulate_ctxt *ctxt,
1257 struct x86_emulate_ops *ops, int irq)
1258 {
1259 struct decode_cache *c = &ctxt->decode;
1260 int rc;
1261 struct desc_ptr dt;
1262 gva_t cs_addr;
1263 gva_t eip_addr;
1264 u16 cs, eip;
1265
1266 /* TODO: Add limit checks */
1267 c->src.val = ctxt->eflags;
1268 emulate_push(ctxt, ops);
1269 rc = writeback(ctxt, ops);
1270 if (rc != X86EMUL_CONTINUE)
1271 return rc;
1272
1273 ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC);
1274
1275 c->src.val = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);
1276 emulate_push(ctxt, ops);
1277 rc = writeback(ctxt, ops);
1278 if (rc != X86EMUL_CONTINUE)
1279 return rc;
1280
1281 c->src.val = c->eip;
1282 emulate_push(ctxt, ops);
1283 rc = writeback(ctxt, ops);
1284 if (rc != X86EMUL_CONTINUE)
1285 return rc;
1286
1287 c->dst.type = OP_NONE;
1288
1289 ops->get_idt(&dt, ctxt->vcpu);
1290
1291 eip_addr = dt.address + (irq << 2);
1292 cs_addr = dt.address + (irq << 2) + 2;
1293
1294 rc = ops->read_std(cs_addr, &cs, 2, ctxt->vcpu, &ctxt->exception);
1295 if (rc != X86EMUL_CONTINUE)
1296 return rc;
1297
1298 rc = ops->read_std(eip_addr, &eip, 2, ctxt->vcpu, &ctxt->exception);
1299 if (rc != X86EMUL_CONTINUE)
1300 return rc;
1301
1302 rc = load_segment_descriptor(ctxt, ops, cs, VCPU_SREG_CS);
1303 if (rc != X86EMUL_CONTINUE)
1304 return rc;
1305
1306 c->eip = eip;
1307
1308 return rc;
1309 }
1310
1311 static int emulate_int(struct x86_emulate_ctxt *ctxt,
1312 struct x86_emulate_ops *ops, int irq)
1313 {
1314 switch(ctxt->mode) {
1315 case X86EMUL_MODE_REAL:
1316 return emulate_int_real(ctxt, ops, irq);
1317 case X86EMUL_MODE_VM86:
1318 case X86EMUL_MODE_PROT16:
1319 case X86EMUL_MODE_PROT32:
1320 case X86EMUL_MODE_PROT64:
1321 default:
1322 /* Protected mode interrupts unimplemented yet */
1323 return X86EMUL_UNHANDLEABLE;
1324 }
1325 }
1326
1327 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt,
1328 struct x86_emulate_ops *ops)
1329 {
1330 struct decode_cache *c = &ctxt->decode;
1331 int rc = X86EMUL_CONTINUE;
1332 unsigned long temp_eip = 0;
1333 unsigned long temp_eflags = 0;
1334 unsigned long cs = 0;
1335 unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF |
1336 EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF |
1337 EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */
1338 unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP;
1339
1340 /* TODO: Add stack limit check */
1341
1342 rc = emulate_pop(ctxt, ops, &temp_eip, c->op_bytes);
1343
1344 if (rc != X86EMUL_CONTINUE)
1345 return rc;
1346
1347 if (temp_eip & ~0xffff)
1348 return emulate_gp(ctxt, 0);
1349
1350 rc = emulate_pop(ctxt, ops, &cs, c->op_bytes);
1351
1352 if (rc != X86EMUL_CONTINUE)
1353 return rc;
1354
1355 rc = emulate_pop(ctxt, ops, &temp_eflags, c->op_bytes);
1356
1357 if (rc != X86EMUL_CONTINUE)
1358 return rc;
1359
1360 rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS);
1361
1362 if (rc != X86EMUL_CONTINUE)
1363 return rc;
1364
1365 c->eip = temp_eip;
1366
1367
1368 if (c->op_bytes == 4)
1369 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
1370 else if (c->op_bytes == 2) {
1371 ctxt->eflags &= ~0xffff;
1372 ctxt->eflags |= temp_eflags;
1373 }
1374
1375 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
1376 ctxt->eflags |= EFLG_RESERVED_ONE_MASK;
1377
1378 return rc;
1379 }
1380
1381 static inline int emulate_iret(struct x86_emulate_ctxt *ctxt,
1382 struct x86_emulate_ops* ops)
1383 {
1384 switch(ctxt->mode) {
1385 case X86EMUL_MODE_REAL:
1386 return emulate_iret_real(ctxt, ops);
1387 case X86EMUL_MODE_VM86:
1388 case X86EMUL_MODE_PROT16:
1389 case X86EMUL_MODE_PROT32:
1390 case X86EMUL_MODE_PROT64:
1391 default:
1392 /* iret from protected mode unimplemented yet */
1393 return X86EMUL_UNHANDLEABLE;
1394 }
1395 }
1396
1397 static inline int emulate_grp1a(struct x86_emulate_ctxt *ctxt,
1398 struct x86_emulate_ops *ops)
1399 {
1400 struct decode_cache *c = &ctxt->decode;
1401
1402 return emulate_pop(ctxt, ops, &c->dst.val, c->dst.bytes);
1403 }
1404
1405 static inline void emulate_grp2(struct x86_emulate_ctxt *ctxt)
1406 {
1407 struct decode_cache *c = &ctxt->decode;
1408 switch (c->modrm_reg) {
1409 case 0: /* rol */
1410 emulate_2op_SrcB("rol", c->src, c->dst, ctxt->eflags);
1411 break;
1412 case 1: /* ror */
1413 emulate_2op_SrcB("ror", c->src, c->dst, ctxt->eflags);
1414 break;
1415 case 2: /* rcl */
1416 emulate_2op_SrcB("rcl", c->src, c->dst, ctxt->eflags);
1417 break;
1418 case 3: /* rcr */
1419 emulate_2op_SrcB("rcr", c->src, c->dst, ctxt->eflags);
1420 break;
1421 case 4: /* sal/shl */
1422 case 6: /* sal/shl */
1423 emulate_2op_SrcB("sal", c->src, c->dst, ctxt->eflags);
1424 break;
1425 case 5: /* shr */
1426 emulate_2op_SrcB("shr", c->src, c->dst, ctxt->eflags);
1427 break;
1428 case 7: /* sar */
1429 emulate_2op_SrcB("sar", c->src, c->dst, ctxt->eflags);
1430 break;
1431 }
1432 }
1433
1434 static inline int emulate_grp3(struct x86_emulate_ctxt *ctxt,
1435 struct x86_emulate_ops *ops)
1436 {
1437 struct decode_cache *c = &ctxt->decode;
1438 unsigned long *rax = &c->regs[VCPU_REGS_RAX];
1439 unsigned long *rdx = &c->regs[VCPU_REGS_RDX];
1440 u8 de = 0;
1441
1442 switch (c->modrm_reg) {
1443 case 0 ... 1: /* test */
1444 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
1445 break;
1446 case 2: /* not */
1447 c->dst.val = ~c->dst.val;
1448 break;
1449 case 3: /* neg */
1450 emulate_1op("neg", c->dst, ctxt->eflags);
1451 break;
1452 case 4: /* mul */
1453 emulate_1op_rax_rdx("mul", c->src, *rax, *rdx, ctxt->eflags);
1454 break;
1455 case 5: /* imul */
1456 emulate_1op_rax_rdx("imul", c->src, *rax, *rdx, ctxt->eflags);
1457 break;
1458 case 6: /* div */
1459 emulate_1op_rax_rdx_ex("div", c->src, *rax, *rdx,
1460 ctxt->eflags, de);
1461 break;
1462 case 7: /* idiv */
1463 emulate_1op_rax_rdx_ex("idiv", c->src, *rax, *rdx,
1464 ctxt->eflags, de);
1465 break;
1466 default:
1467 return X86EMUL_UNHANDLEABLE;
1468 }
1469 if (de)
1470 return emulate_de(ctxt);
1471 return X86EMUL_CONTINUE;
1472 }
1473
1474 static inline int emulate_grp45(struct x86_emulate_ctxt *ctxt,
1475 struct x86_emulate_ops *ops)
1476 {
1477 struct decode_cache *c = &ctxt->decode;
1478
1479 switch (c->modrm_reg) {
1480 case 0: /* inc */
1481 emulate_1op("inc", c->dst, ctxt->eflags);
1482 break;
1483 case 1: /* dec */
1484 emulate_1op("dec", c->dst, ctxt->eflags);
1485 break;
1486 case 2: /* call near abs */ {
1487 long int old_eip;
1488 old_eip = c->eip;
1489 c->eip = c->src.val;
1490 c->src.val = old_eip;
1491 emulate_push(ctxt, ops);
1492 break;
1493 }
1494 case 4: /* jmp abs */
1495 c->eip = c->src.val;
1496 break;
1497 case 6: /* push */
1498 emulate_push(ctxt, ops);
1499 break;
1500 }
1501 return X86EMUL_CONTINUE;
1502 }
1503
1504 static inline int emulate_grp9(struct x86_emulate_ctxt *ctxt,
1505 struct x86_emulate_ops *ops)
1506 {
1507 struct decode_cache *c = &ctxt->decode;
1508 u64 old = c->dst.orig_val64;
1509
1510 if (((u32) (old >> 0) != (u32) c->regs[VCPU_REGS_RAX]) ||
1511 ((u32) (old >> 32) != (u32) c->regs[VCPU_REGS_RDX])) {
1512 c->regs[VCPU_REGS_RAX] = (u32) (old >> 0);
1513 c->regs[VCPU_REGS_RDX] = (u32) (old >> 32);
1514 ctxt->eflags &= ~EFLG_ZF;
1515 } else {
1516 c->dst.val64 = ((u64)c->regs[VCPU_REGS_RCX] << 32) |
1517 (u32) c->regs[VCPU_REGS_RBX];
1518
1519 ctxt->eflags |= EFLG_ZF;
1520 }
1521 return X86EMUL_CONTINUE;
1522 }
1523
1524 static int emulate_ret_far(struct x86_emulate_ctxt *ctxt,
1525 struct x86_emulate_ops *ops)
1526 {
1527 struct decode_cache *c = &ctxt->decode;
1528 int rc;
1529 unsigned long cs;
1530
1531 rc = emulate_pop(ctxt, ops, &c->eip, c->op_bytes);
1532 if (rc != X86EMUL_CONTINUE)
1533 return rc;
1534 if (c->op_bytes == 4)
1535 c->eip = (u32)c->eip;
1536 rc = emulate_pop(ctxt, ops, &cs, c->op_bytes);
1537 if (rc != X86EMUL_CONTINUE)
1538 return rc;
1539 rc = load_segment_descriptor(ctxt, ops, (u16)cs, VCPU_SREG_CS);
1540 return rc;
1541 }
1542
1543 static int emulate_load_segment(struct x86_emulate_ctxt *ctxt,
1544 struct x86_emulate_ops *ops, int seg)
1545 {
1546 struct decode_cache *c = &ctxt->decode;
1547 unsigned short sel;
1548 int rc;
1549
1550 memcpy(&sel, c->src.valptr + c->op_bytes, 2);
1551
1552 rc = load_segment_descriptor(ctxt, ops, sel, seg);
1553 if (rc != X86EMUL_CONTINUE)
1554 return rc;
1555
1556 c->dst.val = c->src.val;
1557 return rc;
1558 }
1559
1560 static inline void
1561 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
1562 struct x86_emulate_ops *ops, struct desc_struct *cs,
1563 struct desc_struct *ss)
1564 {
1565 memset(cs, 0, sizeof(struct desc_struct));
1566 ops->get_cached_descriptor(cs, NULL, VCPU_SREG_CS, ctxt->vcpu);
1567 memset(ss, 0, sizeof(struct desc_struct));
1568
1569 cs->l = 0; /* will be adjusted later */
1570 set_desc_base(cs, 0); /* flat segment */
1571 cs->g = 1; /* 4kb granularity */
1572 set_desc_limit(cs, 0xfffff); /* 4GB limit */
1573 cs->type = 0x0b; /* Read, Execute, Accessed */
1574 cs->s = 1;
1575 cs->dpl = 0; /* will be adjusted later */
1576 cs->p = 1;
1577 cs->d = 1;
1578
1579 set_desc_base(ss, 0); /* flat segment */
1580 set_desc_limit(ss, 0xfffff); /* 4GB limit */
1581 ss->g = 1; /* 4kb granularity */
1582 ss->s = 1;
1583 ss->type = 0x03; /* Read/Write, Accessed */
1584 ss->d = 1; /* 32bit stack segment */
1585 ss->dpl = 0;
1586 ss->p = 1;
1587 }
1588
1589 static int
1590 emulate_syscall(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
1591 {
1592 struct decode_cache *c = &ctxt->decode;
1593 struct desc_struct cs, ss;
1594 u64 msr_data;
1595 u16 cs_sel, ss_sel;
1596
1597 /* syscall is not available in real mode */
1598 if (ctxt->mode == X86EMUL_MODE_REAL ||
1599 ctxt->mode == X86EMUL_MODE_VM86)
1600 return emulate_ud(ctxt);
1601
1602 setup_syscalls_segments(ctxt, ops, &cs, &ss);
1603
1604 ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data);
1605 msr_data >>= 32;
1606 cs_sel = (u16)(msr_data & 0xfffc);
1607 ss_sel = (u16)(msr_data + 8);
1608
1609 if (is_long_mode(ctxt->vcpu)) {
1610 cs.d = 0;
1611 cs.l = 1;
1612 }
1613 ops->set_cached_descriptor(&cs, 0, VCPU_SREG_CS, ctxt->vcpu);
1614 ops->set_segment_selector(cs_sel, VCPU_SREG_CS, ctxt->vcpu);
1615 ops->set_cached_descriptor(&ss, 0, VCPU_SREG_SS, ctxt->vcpu);
1616 ops->set_segment_selector(ss_sel, VCPU_SREG_SS, ctxt->vcpu);
1617
1618 c->regs[VCPU_REGS_RCX] = c->eip;
1619 if (is_long_mode(ctxt->vcpu)) {
1620 #ifdef CONFIG_X86_64
1621 c->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF;
1622
1623 ops->get_msr(ctxt->vcpu,
1624 ctxt->mode == X86EMUL_MODE_PROT64 ?
1625 MSR_LSTAR : MSR_CSTAR, &msr_data);
1626 c->eip = msr_data;
1627
1628 ops->get_msr(ctxt->vcpu, MSR_SYSCALL_MASK, &msr_data);
1629 ctxt->eflags &= ~(msr_data | EFLG_RF);
1630 #endif
1631 } else {
1632 /* legacy mode */
1633 ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data);
1634 c->eip = (u32)msr_data;
1635
1636 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1637 }
1638
1639 return X86EMUL_CONTINUE;
1640 }
1641
1642 static int
1643 emulate_sysenter(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
1644 {
1645 struct decode_cache *c = &ctxt->decode;
1646 struct desc_struct cs, ss;
1647 u64 msr_data;
1648 u16 cs_sel, ss_sel;
1649
1650 /* inject #GP if in real mode */
1651 if (ctxt->mode == X86EMUL_MODE_REAL)
1652 return emulate_gp(ctxt, 0);
1653
1654 /* XXX sysenter/sysexit have not been tested in 64bit mode.
1655 * Therefore, we inject an #UD.
1656 */
1657 if (ctxt->mode == X86EMUL_MODE_PROT64)
1658 return emulate_ud(ctxt);
1659
1660 setup_syscalls_segments(ctxt, ops, &cs, &ss);
1661
1662 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data);
1663 switch (ctxt->mode) {
1664 case X86EMUL_MODE_PROT32:
1665 if ((msr_data & 0xfffc) == 0x0)
1666 return emulate_gp(ctxt, 0);
1667 break;
1668 case X86EMUL_MODE_PROT64:
1669 if (msr_data == 0x0)
1670 return emulate_gp(ctxt, 0);
1671 break;
1672 }
1673
1674 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1675 cs_sel = (u16)msr_data;
1676 cs_sel &= ~SELECTOR_RPL_MASK;
1677 ss_sel = cs_sel + 8;
1678 ss_sel &= ~SELECTOR_RPL_MASK;
1679 if (ctxt->mode == X86EMUL_MODE_PROT64
1680 || is_long_mode(ctxt->vcpu)) {
1681 cs.d = 0;
1682 cs.l = 1;
1683 }
1684
1685 ops->set_cached_descriptor(&cs, 0, VCPU_SREG_CS, ctxt->vcpu);
1686 ops->set_segment_selector(cs_sel, VCPU_SREG_CS, ctxt->vcpu);
1687 ops->set_cached_descriptor(&ss, 0, VCPU_SREG_SS, ctxt->vcpu);
1688 ops->set_segment_selector(ss_sel, VCPU_SREG_SS, ctxt->vcpu);
1689
1690 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_EIP, &msr_data);
1691 c->eip = msr_data;
1692
1693 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_ESP, &msr_data);
1694 c->regs[VCPU_REGS_RSP] = msr_data;
1695
1696 return X86EMUL_CONTINUE;
1697 }
1698
1699 static int
1700 emulate_sysexit(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
1701 {
1702 struct decode_cache *c = &ctxt->decode;
1703 struct desc_struct cs, ss;
1704 u64 msr_data;
1705 int usermode;
1706 u16 cs_sel, ss_sel;
1707
1708 /* inject #GP if in real mode or Virtual 8086 mode */
1709 if (ctxt->mode == X86EMUL_MODE_REAL ||
1710 ctxt->mode == X86EMUL_MODE_VM86)
1711 return emulate_gp(ctxt, 0);
1712
1713 setup_syscalls_segments(ctxt, ops, &cs, &ss);
1714
1715 if ((c->rex_prefix & 0x8) != 0x0)
1716 usermode = X86EMUL_MODE_PROT64;
1717 else
1718 usermode = X86EMUL_MODE_PROT32;
1719
1720 cs.dpl = 3;
1721 ss.dpl = 3;
1722 ops->get_msr(ctxt->vcpu, MSR_IA32_SYSENTER_CS, &msr_data);
1723 switch (usermode) {
1724 case X86EMUL_MODE_PROT32:
1725 cs_sel = (u16)(msr_data + 16);
1726 if ((msr_data & 0xfffc) == 0x0)
1727 return emulate_gp(ctxt, 0);
1728 ss_sel = (u16)(msr_data + 24);
1729 break;
1730 case X86EMUL_MODE_PROT64:
1731 cs_sel = (u16)(msr_data + 32);
1732 if (msr_data == 0x0)
1733 return emulate_gp(ctxt, 0);
1734 ss_sel = cs_sel + 8;
1735 cs.d = 0;
1736 cs.l = 1;
1737 break;
1738 }
1739 cs_sel |= SELECTOR_RPL_MASK;
1740 ss_sel |= SELECTOR_RPL_MASK;
1741
1742 ops->set_cached_descriptor(&cs, 0, VCPU_SREG_CS, ctxt->vcpu);
1743 ops->set_segment_selector(cs_sel, VCPU_SREG_CS, ctxt->vcpu);
1744 ops->set_cached_descriptor(&ss, 0, VCPU_SREG_SS, ctxt->vcpu);
1745 ops->set_segment_selector(ss_sel, VCPU_SREG_SS, ctxt->vcpu);
1746
1747 c->eip = c->regs[VCPU_REGS_RDX];
1748 c->regs[VCPU_REGS_RSP] = c->regs[VCPU_REGS_RCX];
1749
1750 return X86EMUL_CONTINUE;
1751 }
1752
1753 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt,
1754 struct x86_emulate_ops *ops)
1755 {
1756 int iopl;
1757 if (ctxt->mode == X86EMUL_MODE_REAL)
1758 return false;
1759 if (ctxt->mode == X86EMUL_MODE_VM86)
1760 return true;
1761 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1762 return ops->cpl(ctxt->vcpu) > iopl;
1763 }
1764
1765 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
1766 struct x86_emulate_ops *ops,
1767 u16 port, u16 len)
1768 {
1769 struct desc_struct tr_seg;
1770 u32 base3;
1771 int r;
1772 u16 io_bitmap_ptr, perm, bit_idx = port & 0x7;
1773 unsigned mask = (1 << len) - 1;
1774 unsigned long base;
1775
1776 ops->get_cached_descriptor(&tr_seg, &base3, VCPU_SREG_TR, ctxt->vcpu);
1777 if (!tr_seg.p)
1778 return false;
1779 if (desc_limit_scaled(&tr_seg) < 103)
1780 return false;
1781 base = get_desc_base(&tr_seg);
1782 #ifdef CONFIG_X86_64
1783 base |= ((u64)base3) << 32;
1784 #endif
1785 r = ops->read_std(base + 102, &io_bitmap_ptr, 2, ctxt->vcpu, NULL);
1786 if (r != X86EMUL_CONTINUE)
1787 return false;
1788 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
1789 return false;
1790 r = ops->read_std(base + io_bitmap_ptr + port/8, &perm, 2, ctxt->vcpu,
1791 NULL);
1792 if (r != X86EMUL_CONTINUE)
1793 return false;
1794 if ((perm >> bit_idx) & mask)
1795 return false;
1796 return true;
1797 }
1798
1799 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
1800 struct x86_emulate_ops *ops,
1801 u16 port, u16 len)
1802 {
1803 if (ctxt->perm_ok)
1804 return true;
1805
1806 if (emulator_bad_iopl(ctxt, ops))
1807 if (!emulator_io_port_access_allowed(ctxt, ops, port, len))
1808 return false;
1809
1810 ctxt->perm_ok = true;
1811
1812 return true;
1813 }
1814
1815 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
1816 struct x86_emulate_ops *ops,
1817 struct tss_segment_16 *tss)
1818 {
1819 struct decode_cache *c = &ctxt->decode;
1820
1821 tss->ip = c->eip;
1822 tss->flag = ctxt->eflags;
1823 tss->ax = c->regs[VCPU_REGS_RAX];
1824 tss->cx = c->regs[VCPU_REGS_RCX];
1825 tss->dx = c->regs[VCPU_REGS_RDX];
1826 tss->bx = c->regs[VCPU_REGS_RBX];
1827 tss->sp = c->regs[VCPU_REGS_RSP];
1828 tss->bp = c->regs[VCPU_REGS_RBP];
1829 tss->si = c->regs[VCPU_REGS_RSI];
1830 tss->di = c->regs[VCPU_REGS_RDI];
1831
1832 tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu);
1833 tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);
1834 tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu);
1835 tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu);
1836 tss->ldt = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu);
1837 }
1838
1839 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
1840 struct x86_emulate_ops *ops,
1841 struct tss_segment_16 *tss)
1842 {
1843 struct decode_cache *c = &ctxt->decode;
1844 int ret;
1845
1846 c->eip = tss->ip;
1847 ctxt->eflags = tss->flag | 2;
1848 c->regs[VCPU_REGS_RAX] = tss->ax;
1849 c->regs[VCPU_REGS_RCX] = tss->cx;
1850 c->regs[VCPU_REGS_RDX] = tss->dx;
1851 c->regs[VCPU_REGS_RBX] = tss->bx;
1852 c->regs[VCPU_REGS_RSP] = tss->sp;
1853 c->regs[VCPU_REGS_RBP] = tss->bp;
1854 c->regs[VCPU_REGS_RSI] = tss->si;
1855 c->regs[VCPU_REGS_RDI] = tss->di;
1856
1857 /*
1858 * SDM says that segment selectors are loaded before segment
1859 * descriptors
1860 */
1861 ops->set_segment_selector(tss->ldt, VCPU_SREG_LDTR, ctxt->vcpu);
1862 ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu);
1863 ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu);
1864 ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu);
1865 ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu);
1866
1867 /*
1868 * Now load segment descriptors. If fault happenes at this stage
1869 * it is handled in a context of new task
1870 */
1871 ret = load_segment_descriptor(ctxt, ops, tss->ldt, VCPU_SREG_LDTR);
1872 if (ret != X86EMUL_CONTINUE)
1873 return ret;
1874 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES);
1875 if (ret != X86EMUL_CONTINUE)
1876 return ret;
1877 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS);
1878 if (ret != X86EMUL_CONTINUE)
1879 return ret;
1880 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS);
1881 if (ret != X86EMUL_CONTINUE)
1882 return ret;
1883 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS);
1884 if (ret != X86EMUL_CONTINUE)
1885 return ret;
1886
1887 return X86EMUL_CONTINUE;
1888 }
1889
1890 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
1891 struct x86_emulate_ops *ops,
1892 u16 tss_selector, u16 old_tss_sel,
1893 ulong old_tss_base, struct desc_struct *new_desc)
1894 {
1895 struct tss_segment_16 tss_seg;
1896 int ret;
1897 u32 new_tss_base = get_desc_base(new_desc);
1898
1899 ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
1900 &ctxt->exception);
1901 if (ret != X86EMUL_CONTINUE)
1902 /* FIXME: need to provide precise fault address */
1903 return ret;
1904
1905 save_state_to_tss16(ctxt, ops, &tss_seg);
1906
1907 ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
1908 &ctxt->exception);
1909 if (ret != X86EMUL_CONTINUE)
1910 /* FIXME: need to provide precise fault address */
1911 return ret;
1912
1913 ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
1914 &ctxt->exception);
1915 if (ret != X86EMUL_CONTINUE)
1916 /* FIXME: need to provide precise fault address */
1917 return ret;
1918
1919 if (old_tss_sel != 0xffff) {
1920 tss_seg.prev_task_link = old_tss_sel;
1921
1922 ret = ops->write_std(new_tss_base,
1923 &tss_seg.prev_task_link,
1924 sizeof tss_seg.prev_task_link,
1925 ctxt->vcpu, &ctxt->exception);
1926 if (ret != X86EMUL_CONTINUE)
1927 /* FIXME: need to provide precise fault address */
1928 return ret;
1929 }
1930
1931 return load_state_from_tss16(ctxt, ops, &tss_seg);
1932 }
1933
1934 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
1935 struct x86_emulate_ops *ops,
1936 struct tss_segment_32 *tss)
1937 {
1938 struct decode_cache *c = &ctxt->decode;
1939
1940 tss->cr3 = ops->get_cr(3, ctxt->vcpu);
1941 tss->eip = c->eip;
1942 tss->eflags = ctxt->eflags;
1943 tss->eax = c->regs[VCPU_REGS_RAX];
1944 tss->ecx = c->regs[VCPU_REGS_RCX];
1945 tss->edx = c->regs[VCPU_REGS_RDX];
1946 tss->ebx = c->regs[VCPU_REGS_RBX];
1947 tss->esp = c->regs[VCPU_REGS_RSP];
1948 tss->ebp = c->regs[VCPU_REGS_RBP];
1949 tss->esi = c->regs[VCPU_REGS_RSI];
1950 tss->edi = c->regs[VCPU_REGS_RDI];
1951
1952 tss->es = ops->get_segment_selector(VCPU_SREG_ES, ctxt->vcpu);
1953 tss->cs = ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);
1954 tss->ss = ops->get_segment_selector(VCPU_SREG_SS, ctxt->vcpu);
1955 tss->ds = ops->get_segment_selector(VCPU_SREG_DS, ctxt->vcpu);
1956 tss->fs = ops->get_segment_selector(VCPU_SREG_FS, ctxt->vcpu);
1957 tss->gs = ops->get_segment_selector(VCPU_SREG_GS, ctxt->vcpu);
1958 tss->ldt_selector = ops->get_segment_selector(VCPU_SREG_LDTR, ctxt->vcpu);
1959 }
1960
1961 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
1962 struct x86_emulate_ops *ops,
1963 struct tss_segment_32 *tss)
1964 {
1965 struct decode_cache *c = &ctxt->decode;
1966 int ret;
1967
1968 if (ops->set_cr(3, tss->cr3, ctxt->vcpu))
1969 return emulate_gp(ctxt, 0);
1970 c->eip = tss->eip;
1971 ctxt->eflags = tss->eflags | 2;
1972 c->regs[VCPU_REGS_RAX] = tss->eax;
1973 c->regs[VCPU_REGS_RCX] = tss->ecx;
1974 c->regs[VCPU_REGS_RDX] = tss->edx;
1975 c->regs[VCPU_REGS_RBX] = tss->ebx;
1976 c->regs[VCPU_REGS_RSP] = tss->esp;
1977 c->regs[VCPU_REGS_RBP] = tss->ebp;
1978 c->regs[VCPU_REGS_RSI] = tss->esi;
1979 c->regs[VCPU_REGS_RDI] = tss->edi;
1980
1981 /*
1982 * SDM says that segment selectors are loaded before segment
1983 * descriptors
1984 */
1985 ops->set_segment_selector(tss->ldt_selector, VCPU_SREG_LDTR, ctxt->vcpu);
1986 ops->set_segment_selector(tss->es, VCPU_SREG_ES, ctxt->vcpu);
1987 ops->set_segment_selector(tss->cs, VCPU_SREG_CS, ctxt->vcpu);
1988 ops->set_segment_selector(tss->ss, VCPU_SREG_SS, ctxt->vcpu);
1989 ops->set_segment_selector(tss->ds, VCPU_SREG_DS, ctxt->vcpu);
1990 ops->set_segment_selector(tss->fs, VCPU_SREG_FS, ctxt->vcpu);
1991 ops->set_segment_selector(tss->gs, VCPU_SREG_GS, ctxt->vcpu);
1992
1993 /*
1994 * Now load segment descriptors. If fault happenes at this stage
1995 * it is handled in a context of new task
1996 */
1997 ret = load_segment_descriptor(ctxt, ops, tss->ldt_selector, VCPU_SREG_LDTR);
1998 if (ret != X86EMUL_CONTINUE)
1999 return ret;
2000 ret = load_segment_descriptor(ctxt, ops, tss->es, VCPU_SREG_ES);
2001 if (ret != X86EMUL_CONTINUE)
2002 return ret;
2003 ret = load_segment_descriptor(ctxt, ops, tss->cs, VCPU_SREG_CS);
2004 if (ret != X86EMUL_CONTINUE)
2005 return ret;
2006 ret = load_segment_descriptor(ctxt, ops, tss->ss, VCPU_SREG_SS);
2007 if (ret != X86EMUL_CONTINUE)
2008 return ret;
2009 ret = load_segment_descriptor(ctxt, ops, tss->ds, VCPU_SREG_DS);
2010 if (ret != X86EMUL_CONTINUE)
2011 return ret;
2012 ret = load_segment_descriptor(ctxt, ops, tss->fs, VCPU_SREG_FS);
2013 if (ret != X86EMUL_CONTINUE)
2014 return ret;
2015 ret = load_segment_descriptor(ctxt, ops, tss->gs, VCPU_SREG_GS);
2016 if (ret != X86EMUL_CONTINUE)
2017 return ret;
2018
2019 return X86EMUL_CONTINUE;
2020 }
2021
2022 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
2023 struct x86_emulate_ops *ops,
2024 u16 tss_selector, u16 old_tss_sel,
2025 ulong old_tss_base, struct desc_struct *new_desc)
2026 {
2027 struct tss_segment_32 tss_seg;
2028 int ret;
2029 u32 new_tss_base = get_desc_base(new_desc);
2030
2031 ret = ops->read_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2032 &ctxt->exception);
2033 if (ret != X86EMUL_CONTINUE)
2034 /* FIXME: need to provide precise fault address */
2035 return ret;
2036
2037 save_state_to_tss32(ctxt, ops, &tss_seg);
2038
2039 ret = ops->write_std(old_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2040 &ctxt->exception);
2041 if (ret != X86EMUL_CONTINUE)
2042 /* FIXME: need to provide precise fault address */
2043 return ret;
2044
2045 ret = ops->read_std(new_tss_base, &tss_seg, sizeof tss_seg, ctxt->vcpu,
2046 &ctxt->exception);
2047 if (ret != X86EMUL_CONTINUE)
2048 /* FIXME: need to provide precise fault address */
2049 return ret;
2050
2051 if (old_tss_sel != 0xffff) {
2052 tss_seg.prev_task_link = old_tss_sel;
2053
2054 ret = ops->write_std(new_tss_base,
2055 &tss_seg.prev_task_link,
2056 sizeof tss_seg.prev_task_link,
2057 ctxt->vcpu, &ctxt->exception);
2058 if (ret != X86EMUL_CONTINUE)
2059 /* FIXME: need to provide precise fault address */
2060 return ret;
2061 }
2062
2063 return load_state_from_tss32(ctxt, ops, &tss_seg);
2064 }
2065
2066 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
2067 struct x86_emulate_ops *ops,
2068 u16 tss_selector, int reason,
2069 bool has_error_code, u32 error_code)
2070 {
2071 struct desc_struct curr_tss_desc, next_tss_desc;
2072 int ret;
2073 u16 old_tss_sel = ops->get_segment_selector(VCPU_SREG_TR, ctxt->vcpu);
2074 ulong old_tss_base =
2075 ops->get_cached_segment_base(VCPU_SREG_TR, ctxt->vcpu);
2076 u32 desc_limit;
2077
2078 /* FIXME: old_tss_base == ~0 ? */
2079
2080 ret = read_segment_descriptor(ctxt, ops, tss_selector, &next_tss_desc);
2081 if (ret != X86EMUL_CONTINUE)
2082 return ret;
2083 ret = read_segment_descriptor(ctxt, ops, old_tss_sel, &curr_tss_desc);
2084 if (ret != X86EMUL_CONTINUE)
2085 return ret;
2086
2087 /* FIXME: check that next_tss_desc is tss */
2088
2089 if (reason != TASK_SWITCH_IRET) {
2090 if ((tss_selector & 3) > next_tss_desc.dpl ||
2091 ops->cpl(ctxt->vcpu) > next_tss_desc.dpl)
2092 return emulate_gp(ctxt, 0);
2093 }
2094
2095 desc_limit = desc_limit_scaled(&next_tss_desc);
2096 if (!next_tss_desc.p ||
2097 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
2098 desc_limit < 0x2b)) {
2099 emulate_ts(ctxt, tss_selector & 0xfffc);
2100 return X86EMUL_PROPAGATE_FAULT;
2101 }
2102
2103 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
2104 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
2105 write_segment_descriptor(ctxt, ops, old_tss_sel,
2106 &curr_tss_desc);
2107 }
2108
2109 if (reason == TASK_SWITCH_IRET)
2110 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
2111
2112 /* set back link to prev task only if NT bit is set in eflags
2113 note that old_tss_sel is not used afetr this point */
2114 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
2115 old_tss_sel = 0xffff;
2116
2117 if (next_tss_desc.type & 8)
2118 ret = task_switch_32(ctxt, ops, tss_selector, old_tss_sel,
2119 old_tss_base, &next_tss_desc);
2120 else
2121 ret = task_switch_16(ctxt, ops, tss_selector, old_tss_sel,
2122 old_tss_base, &next_tss_desc);
2123 if (ret != X86EMUL_CONTINUE)
2124 return ret;
2125
2126 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
2127 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
2128
2129 if (reason != TASK_SWITCH_IRET) {
2130 next_tss_desc.type |= (1 << 1); /* set busy flag */
2131 write_segment_descriptor(ctxt, ops, tss_selector,
2132 &next_tss_desc);
2133 }
2134
2135 ops->set_cr(0, ops->get_cr(0, ctxt->vcpu) | X86_CR0_TS, ctxt->vcpu);
2136 ops->set_cached_descriptor(&next_tss_desc, 0, VCPU_SREG_TR, ctxt->vcpu);
2137 ops->set_segment_selector(tss_selector, VCPU_SREG_TR, ctxt->vcpu);
2138
2139 if (has_error_code) {
2140 struct decode_cache *c = &ctxt->decode;
2141
2142 c->op_bytes = c->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
2143 c->lock_prefix = 0;
2144 c->src.val = (unsigned long) error_code;
2145 emulate_push(ctxt, ops);
2146 }
2147
2148 return ret;
2149 }
2150
2151 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
2152 u16 tss_selector, int reason,
2153 bool has_error_code, u32 error_code)
2154 {
2155 struct x86_emulate_ops *ops = ctxt->ops;
2156 struct decode_cache *c = &ctxt->decode;
2157 int rc;
2158
2159 c->eip = ctxt->eip;
2160 c->dst.type = OP_NONE;
2161
2162 rc = emulator_do_task_switch(ctxt, ops, tss_selector, reason,
2163 has_error_code, error_code);
2164
2165 if (rc == X86EMUL_CONTINUE) {
2166 rc = writeback(ctxt, ops);
2167 if (rc == X86EMUL_CONTINUE)
2168 ctxt->eip = c->eip;
2169 }
2170
2171 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
2172 }
2173
2174 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned seg,
2175 int reg, struct operand *op)
2176 {
2177 struct decode_cache *c = &ctxt->decode;
2178 int df = (ctxt->eflags & EFLG_DF) ? -1 : 1;
2179
2180 register_address_increment(c, &c->regs[reg], df * op->bytes);
2181 op->addr.mem.ea = register_address(c, c->regs[reg]);
2182 op->addr.mem.seg = seg;
2183 }
2184
2185 static int em_push(struct x86_emulate_ctxt *ctxt)
2186 {
2187 emulate_push(ctxt, ctxt->ops);
2188 return X86EMUL_CONTINUE;
2189 }
2190
2191 static int em_das(struct x86_emulate_ctxt *ctxt)
2192 {
2193 struct decode_cache *c = &ctxt->decode;
2194 u8 al, old_al;
2195 bool af, cf, old_cf;
2196
2197 cf = ctxt->eflags & X86_EFLAGS_CF;
2198 al = c->dst.val;
2199
2200 old_al = al;
2201 old_cf = cf;
2202 cf = false;
2203 af = ctxt->eflags & X86_EFLAGS_AF;
2204 if ((al & 0x0f) > 9 || af) {
2205 al -= 6;
2206 cf = old_cf | (al >= 250);
2207 af = true;
2208 } else {
2209 af = false;
2210 }
2211 if (old_al > 0x99 || old_cf) {
2212 al -= 0x60;
2213 cf = true;
2214 }
2215
2216 c->dst.val = al;
2217 /* Set PF, ZF, SF */
2218 c->src.type = OP_IMM;
2219 c->src.val = 0;
2220 c->src.bytes = 1;
2221 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags);
2222 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);
2223 if (cf)
2224 ctxt->eflags |= X86_EFLAGS_CF;
2225 if (af)
2226 ctxt->eflags |= X86_EFLAGS_AF;
2227 return X86EMUL_CONTINUE;
2228 }
2229
2230 static int em_call_far(struct x86_emulate_ctxt *ctxt)
2231 {
2232 struct decode_cache *c = &ctxt->decode;
2233 u16 sel, old_cs;
2234 ulong old_eip;
2235 int rc;
2236
2237 old_cs = ctxt->ops->get_segment_selector(VCPU_SREG_CS, ctxt->vcpu);
2238 old_eip = c->eip;
2239
2240 memcpy(&sel, c->src.valptr + c->op_bytes, 2);
2241 if (load_segment_descriptor(ctxt, ctxt->ops, sel, VCPU_SREG_CS))
2242 return X86EMUL_CONTINUE;
2243
2244 c->eip = 0;
2245 memcpy(&c->eip, c->src.valptr, c->op_bytes);
2246
2247 c->src.val = old_cs;
2248 emulate_push(ctxt, ctxt->ops);
2249 rc = writeback(ctxt, ctxt->ops);
2250 if (rc != X86EMUL_CONTINUE)
2251 return rc;
2252
2253 c->src.val = old_eip;
2254 emulate_push(ctxt, ctxt->ops);
2255 rc = writeback(ctxt, ctxt->ops);
2256 if (rc != X86EMUL_CONTINUE)
2257 return rc;
2258
2259 c->dst.type = OP_NONE;
2260
2261 return X86EMUL_CONTINUE;
2262 }
2263
2264 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
2265 {
2266 struct decode_cache *c = &ctxt->decode;
2267 int rc;
2268
2269 c->dst.type = OP_REG;
2270 c->dst.addr.reg = &c->eip;
2271 c->dst.bytes = c->op_bytes;
2272 rc = emulate_pop(ctxt, ctxt->ops, &c->dst.val, c->op_bytes);
2273 if (rc != X86EMUL_CONTINUE)
2274 return rc;
2275 register_address_increment(c, &c->regs[VCPU_REGS_RSP], c->src.val);
2276 return X86EMUL_CONTINUE;
2277 }
2278
2279 static int em_imul(struct x86_emulate_ctxt *ctxt)
2280 {
2281 struct decode_cache *c = &ctxt->decode;
2282
2283 emulate_2op_SrcV_nobyte("imul", c->src, c->dst, ctxt->eflags);
2284 return X86EMUL_CONTINUE;
2285 }
2286
2287 static int em_imul_3op(struct x86_emulate_ctxt *ctxt)
2288 {
2289 struct decode_cache *c = &ctxt->decode;
2290
2291 c->dst.val = c->src2.val;
2292 return em_imul(ctxt);
2293 }
2294
2295 static int em_cwd(struct x86_emulate_ctxt *ctxt)
2296 {
2297 struct decode_cache *c = &ctxt->decode;
2298
2299 c->dst.type = OP_REG;
2300 c->dst.bytes = c->src.bytes;
2301 c->dst.addr.reg = &c->regs[VCPU_REGS_RDX];
2302 c->dst.val = ~((c->src.val >> (c->src.bytes * 8 - 1)) - 1);
2303
2304 return X86EMUL_CONTINUE;
2305 }
2306
2307 static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
2308 {
2309 unsigned cpl = ctxt->ops->cpl(ctxt->vcpu);
2310 struct decode_cache *c = &ctxt->decode;
2311 u64 tsc = 0;
2312
2313 if (cpl > 0 && (ctxt->ops->get_cr(4, ctxt->vcpu) & X86_CR4_TSD))
2314 return emulate_gp(ctxt, 0);
2315 ctxt->ops->get_msr(ctxt->vcpu, MSR_IA32_TSC, &tsc);
2316 c->regs[VCPU_REGS_RAX] = (u32)tsc;
2317 c->regs[VCPU_REGS_RDX] = tsc >> 32;
2318 return X86EMUL_CONTINUE;
2319 }
2320
2321 static int em_mov(struct x86_emulate_ctxt *ctxt)
2322 {
2323 struct decode_cache *c = &ctxt->decode;
2324 c->dst.val = c->src.val;
2325 return X86EMUL_CONTINUE;
2326 }
2327
2328 #define D(_y) { .flags = (_y) }
2329 #define N D(0)
2330 #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
2331 #define GD(_f, _g) { .flags = ((_f) | Group | GroupDual), .u.gdual = (_g) }
2332 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
2333
2334 #define D2bv(_f) D((_f) | ByteOp), D(_f)
2335 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e)
2336
2337 #define D6ALU(_f) D2bv((_f) | DstMem | SrcReg | ModRM), \
2338 D2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock), \
2339 D2bv(((_f) & ~Lock) | DstAcc | SrcImm)
2340
2341
2342 static struct opcode group1[] = {
2343 X7(D(Lock)), N
2344 };
2345
2346 static struct opcode group1A[] = {
2347 D(DstMem | SrcNone | ModRM | Mov | Stack), N, N, N, N, N, N, N,
2348 };
2349
2350 static struct opcode group3[] = {
2351 D(DstMem | SrcImm | ModRM), D(DstMem | SrcImm | ModRM),
2352 D(DstMem | SrcNone | ModRM | Lock), D(DstMem | SrcNone | ModRM | Lock),
2353 X4(D(SrcMem | ModRM)),
2354 };
2355
2356 static struct opcode group4[] = {
2357 D(ByteOp | DstMem | SrcNone | ModRM | Lock), D(ByteOp | DstMem | SrcNone | ModRM | Lock),
2358 N, N, N, N, N, N,
2359 };
2360
2361 static struct opcode group5[] = {
2362 D(DstMem | SrcNone | ModRM | Lock), D(DstMem | SrcNone | ModRM | Lock),
2363 D(SrcMem | ModRM | Stack),
2364 I(SrcMemFAddr | ModRM | ImplicitOps | Stack, em_call_far),
2365 D(SrcMem | ModRM | Stack), D(SrcMemFAddr | ModRM | ImplicitOps),
2366 D(SrcMem | ModRM | Stack), N,
2367 };
2368
2369 static struct group_dual group7 = { {
2370 N, N, D(ModRM | SrcMem | Priv), D(ModRM | SrcMem | Priv),
2371 D(SrcNone | ModRM | DstMem | Mov), N,
2372 D(SrcMem16 | ModRM | Mov | Priv),
2373 D(SrcMem | ModRM | ByteOp | Priv | NoAccess),
2374 }, {
2375 D(SrcNone | ModRM | Priv | VendorSpecific), N,
2376 N, D(SrcNone | ModRM | Priv | VendorSpecific),
2377 D(SrcNone | ModRM | DstMem | Mov), N,
2378 D(SrcMem16 | ModRM | Mov | Priv), N,
2379 } };
2380
2381 static struct opcode group8[] = {
2382 N, N, N, N,
2383 D(DstMem | SrcImmByte | ModRM), D(DstMem | SrcImmByte | ModRM | Lock),
2384 D(DstMem | SrcImmByte | ModRM | Lock), D(DstMem | SrcImmByte | ModRM | Lock),
2385 };
2386
2387 static struct group_dual group9 = { {
2388 N, D(DstMem64 | ModRM | Lock), N, N, N, N, N, N,
2389 }, {
2390 N, N, N, N, N, N, N, N,
2391 } };
2392
2393 static struct opcode group11[] = {
2394 I(DstMem | SrcImm | ModRM | Mov, em_mov), X7(D(Undefined)),
2395 };
2396
2397 static struct opcode opcode_table[256] = {
2398 /* 0x00 - 0x07 */
2399 D6ALU(Lock),
2400 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
2401 /* 0x08 - 0x0F */
2402 D6ALU(Lock),
2403 D(ImplicitOps | Stack | No64), N,
2404 /* 0x10 - 0x17 */
2405 D6ALU(Lock),
2406 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
2407 /* 0x18 - 0x1F */
2408 D6ALU(Lock),
2409 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
2410 /* 0x20 - 0x27 */
2411 D6ALU(Lock), N, N,
2412 /* 0x28 - 0x2F */
2413 D6ALU(Lock), N, I(ByteOp | DstAcc | No64, em_das),
2414 /* 0x30 - 0x37 */
2415 D6ALU(Lock), N, N,
2416 /* 0x38 - 0x3F */
2417 D6ALU(0), N, N,
2418 /* 0x40 - 0x4F */
2419 X16(D(DstReg)),
2420 /* 0x50 - 0x57 */
2421 X8(I(SrcReg | Stack, em_push)),
2422 /* 0x58 - 0x5F */
2423 X8(D(DstReg | Stack)),
2424 /* 0x60 - 0x67 */
2425 D(ImplicitOps | Stack | No64), D(ImplicitOps | Stack | No64),
2426 N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ ,
2427 N, N, N, N,
2428 /* 0x68 - 0x6F */
2429 I(SrcImm | Mov | Stack, em_push),
2430 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
2431 I(SrcImmByte | Mov | Stack, em_push),
2432 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
2433 D2bv(DstDI | Mov | String), /* insb, insw/insd */
2434 D2bv(SrcSI | ImplicitOps | String), /* outsb, outsw/outsd */
2435 /* 0x70 - 0x7F */
2436 X16(D(SrcImmByte)),
2437 /* 0x80 - 0x87 */
2438 G(ByteOp | DstMem | SrcImm | ModRM | Group, group1),
2439 G(DstMem | SrcImm | ModRM | Group, group1),
2440 G(ByteOp | DstMem | SrcImm | ModRM | No64 | Group, group1),
2441 G(DstMem | SrcImmByte | ModRM | Group, group1),
2442 D2bv(DstMem | SrcReg | ModRM), D2bv(DstMem | SrcReg | ModRM | Lock),
2443 /* 0x88 - 0x8F */
2444 I2bv(DstMem | SrcReg | ModRM | Mov, em_mov),
2445 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
2446 D(DstMem | SrcNone | ModRM | Mov), D(ModRM | SrcMem | NoAccess | DstReg),
2447 D(ImplicitOps | SrcMem16 | ModRM), G(0, group1A),
2448 /* 0x90 - 0x97 */
2449 X8(D(SrcAcc | DstReg)),
2450 /* 0x98 - 0x9F */
2451 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
2452 I(SrcImmFAddr | No64, em_call_far), N,
2453 D(ImplicitOps | Stack), D(ImplicitOps | Stack), N, N,
2454 /* 0xA0 - 0xA7 */
2455 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
2456 I2bv(DstMem | SrcAcc | Mov | MemAbs, em_mov),
2457 I2bv(SrcSI | DstDI | Mov | String, em_mov),
2458 D2bv(SrcSI | DstDI | String),
2459 /* 0xA8 - 0xAF */
2460 D2bv(DstAcc | SrcImm),
2461 I2bv(SrcAcc | DstDI | Mov | String, em_mov),
2462 I2bv(SrcSI | DstAcc | Mov | String, em_mov),
2463 D2bv(SrcAcc | DstDI | String),
2464 /* 0xB0 - 0xB7 */
2465 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
2466 /* 0xB8 - 0xBF */
2467 X8(I(DstReg | SrcImm | Mov, em_mov)),
2468 /* 0xC0 - 0xC7 */
2469 D2bv(DstMem | SrcImmByte | ModRM),
2470 I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),
2471 D(ImplicitOps | Stack),
2472 D(DstReg | SrcMemFAddr | ModRM | No64), D(DstReg | SrcMemFAddr | ModRM | No64),
2473 G(ByteOp, group11), G(0, group11),
2474 /* 0xC8 - 0xCF */
2475 N, N, N, D(ImplicitOps | Stack),
2476 D(ImplicitOps), D(SrcImmByte), D(ImplicitOps | No64), D(ImplicitOps),
2477 /* 0xD0 - 0xD7 */
2478 D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM),
2479 N, N, N, N,
2480 /* 0xD8 - 0xDF */
2481 N, N, N, N, N, N, N, N,
2482 /* 0xE0 - 0xE7 */
2483 X4(D(SrcImmByte)),
2484 D2bv(SrcImmUByte | DstAcc), D2bv(SrcAcc | DstImmUByte),
2485 /* 0xE8 - 0xEF */
2486 D(SrcImm | Stack), D(SrcImm | ImplicitOps),
2487 D(SrcImmFAddr | No64), D(SrcImmByte | ImplicitOps),
2488 D2bv(SrcNone | DstAcc), D2bv(SrcAcc | ImplicitOps),
2489 /* 0xF0 - 0xF7 */
2490 N, N, N, N,
2491 D(ImplicitOps | Priv), D(ImplicitOps), G(ByteOp, group3), G(0, group3),
2492 /* 0xF8 - 0xFF */
2493 D(ImplicitOps), D(ImplicitOps), D(ImplicitOps), D(ImplicitOps),
2494 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5),
2495 };
2496
2497 static struct opcode twobyte_table[256] = {
2498 /* 0x00 - 0x0F */
2499 N, GD(0, &group7), N, N,
2500 N, D(ImplicitOps | VendorSpecific), D(ImplicitOps | Priv), N,
2501 D(ImplicitOps | Priv), D(ImplicitOps | Priv), N, N,
2502 N, D(ImplicitOps | ModRM), N, N,
2503 /* 0x10 - 0x1F */
2504 N, N, N, N, N, N, N, N, D(ImplicitOps | ModRM), N, N, N, N, N, N, N,
2505 /* 0x20 - 0x2F */
2506 D(ModRM | DstMem | Priv | Op3264), D(ModRM | DstMem | Priv | Op3264),
2507 D(ModRM | SrcMem | Priv | Op3264), D(ModRM | SrcMem | Priv | Op3264),
2508 N, N, N, N,
2509 N, N, N, N, N, N, N, N,
2510 /* 0x30 - 0x3F */
2511 D(ImplicitOps | Priv), I(ImplicitOps, em_rdtsc),
2512 D(ImplicitOps | Priv), N,
2513 D(ImplicitOps | VendorSpecific), D(ImplicitOps | Priv | VendorSpecific),
2514 N, N,
2515 N, N, N, N, N, N, N, N,
2516 /* 0x40 - 0x4F */
2517 X16(D(DstReg | SrcMem | ModRM | Mov)),
2518 /* 0x50 - 0x5F */
2519 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
2520 /* 0x60 - 0x6F */
2521 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
2522 /* 0x70 - 0x7F */
2523 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
2524 /* 0x80 - 0x8F */
2525 X16(D(SrcImm)),
2526 /* 0x90 - 0x9F */
2527 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
2528 /* 0xA0 - 0xA7 */
2529 D(ImplicitOps | Stack), D(ImplicitOps | Stack),
2530 N, D(DstMem | SrcReg | ModRM | BitOp),
2531 D(DstMem | SrcReg | Src2ImmByte | ModRM),
2532 D(DstMem | SrcReg | Src2CL | ModRM), N, N,
2533 /* 0xA8 - 0xAF */
2534 D(ImplicitOps | Stack), D(ImplicitOps | Stack),
2535 N, D(DstMem | SrcReg | ModRM | BitOp | Lock),
2536 D(DstMem | SrcReg | Src2ImmByte | ModRM),
2537 D(DstMem | SrcReg | Src2CL | ModRM),
2538 D(ModRM), I(DstReg | SrcMem | ModRM, em_imul),
2539 /* 0xB0 - 0xB7 */
2540 D2bv(DstMem | SrcReg | ModRM | Lock),
2541 D(DstReg | SrcMemFAddr | ModRM), D(DstMem | SrcReg | ModRM | BitOp | Lock),
2542 D(DstReg | SrcMemFAddr | ModRM), D(DstReg | SrcMemFAddr | ModRM),
2543 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
2544 /* 0xB8 - 0xBF */
2545 N, N,
2546 G(BitOp, group8), D(DstMem | SrcReg | ModRM | BitOp | Lock),
2547 D(DstReg | SrcMem | ModRM), D(DstReg | SrcMem | ModRM),
2548 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
2549 /* 0xC0 - 0xCF */
2550 D2bv(DstMem | SrcReg | ModRM | Lock),
2551 N, D(DstMem | SrcReg | ModRM | Mov),
2552 N, N, N, GD(0, &group9),
2553 N, N, N, N, N, N, N, N,
2554 /* 0xD0 - 0xDF */
2555 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
2556 /* 0xE0 - 0xEF */
2557 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
2558 /* 0xF0 - 0xFF */
2559 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N
2560 };
2561
2562 #undef D
2563 #undef N
2564 #undef G
2565 #undef GD
2566 #undef I
2567
2568 #undef D2bv
2569 #undef I2bv
2570 #undef D6ALU
2571
2572 static unsigned imm_size(struct decode_cache *c)
2573 {
2574 unsigned size;
2575
2576 size = (c->d & ByteOp) ? 1 : c->op_bytes;
2577 if (size == 8)
2578 size = 4;
2579 return size;
2580 }
2581
2582 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op,
2583 unsigned size, bool sign_extension)
2584 {
2585 struct decode_cache *c = &ctxt->decode;
2586 struct x86_emulate_ops *ops = ctxt->ops;
2587 int rc = X86EMUL_CONTINUE;
2588
2589 op->type = OP_IMM;
2590 op->bytes = size;
2591 op->addr.mem.ea = c->eip;
2592 /* NB. Immediates are sign-extended as necessary. */
2593 switch (op->bytes) {
2594 case 1:
2595 op->val = insn_fetch(s8, 1, c->eip);
2596 break;
2597 case 2:
2598 op->val = insn_fetch(s16, 2, c->eip);
2599 break;
2600 case 4:
2601 op->val = insn_fetch(s32, 4, c->eip);
2602 break;
2603 }
2604 if (!sign_extension) {
2605 switch (op->bytes) {
2606 case 1:
2607 op->val &= 0xff;
2608 break;
2609 case 2:
2610 op->val &= 0xffff;
2611 break;
2612 case 4:
2613 op->val &= 0xffffffff;
2614 break;
2615 }
2616 }
2617 done:
2618 return rc;
2619 }
2620
2621 int
2622 x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
2623 {
2624 struct x86_emulate_ops *ops = ctxt->ops;
2625 struct decode_cache *c = &ctxt->decode;
2626 int rc = X86EMUL_CONTINUE;
2627 int mode = ctxt->mode;
2628 int def_op_bytes, def_ad_bytes, dual, goffset;
2629 struct opcode opcode, *g_mod012, *g_mod3;
2630 struct operand memop = { .type = OP_NONE };
2631
2632 c->eip = ctxt->eip;
2633 c->fetch.start = c->eip;
2634 c->fetch.end = c->fetch.start + insn_len;
2635 if (insn_len > 0)
2636 memcpy(c->fetch.data, insn, insn_len);
2637 ctxt->cs_base = seg_base(ctxt, ops, VCPU_SREG_CS);
2638
2639 switch (mode) {
2640 case X86EMUL_MODE_REAL:
2641 case X86EMUL_MODE_VM86:
2642 case X86EMUL_MODE_PROT16:
2643 def_op_bytes = def_ad_bytes = 2;
2644 break;
2645 case X86EMUL_MODE_PROT32:
2646 def_op_bytes = def_ad_bytes = 4;
2647 break;
2648 #ifdef CONFIG_X86_64
2649 case X86EMUL_MODE_PROT64:
2650 def_op_bytes = 4;
2651 def_ad_bytes = 8;
2652 break;
2653 #endif
2654 default:
2655 return -1;
2656 }
2657
2658 c->op_bytes = def_op_bytes;
2659 c->ad_bytes = def_ad_bytes;
2660
2661 /* Legacy prefixes. */
2662 for (;;) {
2663 switch (c->b = insn_fetch(u8, 1, c->eip)) {
2664 case 0x66: /* operand-size override */
2665 /* switch between 2/4 bytes */
2666 c->op_bytes = def_op_bytes ^ 6;
2667 break;
2668 case 0x67: /* address-size override */
2669 if (mode == X86EMUL_MODE_PROT64)
2670 /* switch between 4/8 bytes */
2671 c->ad_bytes = def_ad_bytes ^ 12;
2672 else
2673 /* switch between 2/4 bytes */
2674 c->ad_bytes = def_ad_bytes ^ 6;
2675 break;
2676 case 0x26: /* ES override */
2677 case 0x2e: /* CS override */
2678 case 0x36: /* SS override */
2679 case 0x3e: /* DS override */
2680 set_seg_override(c, (c->b >> 3) & 3);
2681 break;
2682 case 0x64: /* FS override */
2683 case 0x65: /* GS override */
2684 set_seg_override(c, c->b & 7);
2685 break;
2686 case 0x40 ... 0x4f: /* REX */
2687 if (mode != X86EMUL_MODE_PROT64)
2688 goto done_prefixes;
2689 c->rex_prefix = c->b;
2690 continue;
2691 case 0xf0: /* LOCK */
2692 c->lock_prefix = 1;
2693 break;
2694 case 0xf2: /* REPNE/REPNZ */
2695 case 0xf3: /* REP/REPE/REPZ */
2696 c->rep_prefix = c->b;
2697 break;
2698 default:
2699 goto done_prefixes;
2700 }
2701
2702 /* Any legacy prefix after a REX prefix nullifies its effect. */
2703
2704 c->rex_prefix = 0;
2705 }
2706
2707 done_prefixes:
2708
2709 /* REX prefix. */
2710 if (c->rex_prefix & 8)
2711 c->op_bytes = 8; /* REX.W */
2712
2713 /* Opcode byte(s). */
2714 opcode = opcode_table[c->b];
2715 /* Two-byte opcode? */
2716 if (c->b == 0x0f) {
2717 c->twobyte = 1;
2718 c->b = insn_fetch(u8, 1, c->eip);
2719 opcode = twobyte_table[c->b];
2720 }
2721 c->d = opcode.flags;
2722
2723 if (c->d & Group) {
2724 dual = c->d & GroupDual;
2725 c->modrm = insn_fetch(u8, 1, c->eip);
2726 --c->eip;
2727
2728 if (c->d & GroupDual) {
2729 g_mod012 = opcode.u.gdual->mod012;
2730 g_mod3 = opcode.u.gdual->mod3;
2731 } else
2732 g_mod012 = g_mod3 = opcode.u.group;
2733
2734 c->d &= ~(Group | GroupDual);
2735
2736 goffset = (c->modrm >> 3) & 7;
2737
2738 if ((c->modrm >> 6) == 3)
2739 opcode = g_mod3[goffset];
2740 else
2741 opcode = g_mod012[goffset];
2742 c->d |= opcode.flags;
2743 }
2744
2745 c->execute = opcode.u.execute;
2746
2747 /* Unrecognised? */
2748 if (c->d == 0 || (c->d & Undefined))
2749 return -1;
2750
2751 if (!(c->d & VendorSpecific) && ctxt->only_vendor_specific_insn)
2752 return -1;
2753
2754 if (mode == X86EMUL_MODE_PROT64 && (c->d & Stack))
2755 c->op_bytes = 8;
2756
2757 if (c->d & Op3264) {
2758 if (mode == X86EMUL_MODE_PROT64)
2759 c->op_bytes = 8;
2760 else
2761 c->op_bytes = 4;
2762 }
2763
2764 /* ModRM and SIB bytes. */
2765 if (c->d & ModRM) {
2766 rc = decode_modrm(ctxt, ops, &memop);
2767 if (!c->has_seg_override)
2768 set_seg_override(c, c->modrm_seg);
2769 } else if (c->d & MemAbs)
2770 rc = decode_abs(ctxt, ops, &memop);
2771 if (rc != X86EMUL_CONTINUE)
2772 goto done;
2773
2774 if (!c->has_seg_override)
2775 set_seg_override(c, VCPU_SREG_DS);
2776
2777 memop.addr.mem.seg = seg_override(ctxt, ops, c);
2778
2779 if (memop.type == OP_MEM && c->ad_bytes != 8)
2780 memop.addr.mem.ea = (u32)memop.addr.mem.ea;
2781
2782 if (memop.type == OP_MEM && c->rip_relative)
2783 memop.addr.mem.ea += c->eip;
2784
2785 /*
2786 * Decode and fetch the source operand: register, memory
2787 * or immediate.
2788 */
2789 switch (c->d & SrcMask) {
2790 case SrcNone:
2791 break;
2792 case SrcReg:
2793 decode_register_operand(&c->src, c, 0);
2794 break;
2795 case SrcMem16:
2796 memop.bytes = 2;
2797 goto srcmem_common;
2798 case SrcMem32:
2799 memop.bytes = 4;
2800 goto srcmem_common;
2801 case SrcMem:
2802 memop.bytes = (c->d & ByteOp) ? 1 :
2803 c->op_bytes;
2804 srcmem_common:
2805 c->src = memop;
2806 break;
2807 case SrcImmU16:
2808 rc = decode_imm(ctxt, &c->src, 2, false);
2809 break;
2810 case SrcImm:
2811 rc = decode_imm(ctxt, &c->src, imm_size(c), true);
2812 break;
2813 case SrcImmU:
2814 rc = decode_imm(ctxt, &c->src, imm_size(c), false);
2815 break;
2816 case SrcImmByte:
2817 rc = decode_imm(ctxt, &c->src, 1, true);
2818 break;
2819 case SrcImmUByte:
2820 rc = decode_imm(ctxt, &c->src, 1, false);
2821 break;
2822 case SrcAcc:
2823 c->src.type = OP_REG;
2824 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
2825 c->src.addr.reg = &c->regs[VCPU_REGS_RAX];
2826 fetch_register_operand(&c->src);
2827 break;
2828 case SrcOne:
2829 c->src.bytes = 1;
2830 c->src.val = 1;
2831 break;
2832 case SrcSI:
2833 c->src.type = OP_MEM;
2834 c->src.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
2835 c->src.addr.mem.ea =
2836 register_address(c, c->regs[VCPU_REGS_RSI]);
2837 c->src.addr.mem.seg = seg_override(ctxt, ops, c),
2838 c->src.val = 0;
2839 break;
2840 case SrcImmFAddr:
2841 c->src.type = OP_IMM;
2842 c->src.addr.mem.ea = c->eip;
2843 c->src.bytes = c->op_bytes + 2;
2844 insn_fetch_arr(c->src.valptr, c->src.bytes, c->eip);
2845 break;
2846 case SrcMemFAddr:
2847 memop.bytes = c->op_bytes + 2;
2848 goto srcmem_common;
2849 break;
2850 }
2851
2852 if (rc != X86EMUL_CONTINUE)
2853 goto done;
2854
2855 /*
2856 * Decode and fetch the second source operand: register, memory
2857 * or immediate.
2858 */
2859 switch (c->d & Src2Mask) {
2860 case Src2None:
2861 break;
2862 case Src2CL:
2863 c->src2.bytes = 1;
2864 c->src2.val = c->regs[VCPU_REGS_RCX] & 0x8;
2865 break;
2866 case Src2ImmByte:
2867 rc = decode_imm(ctxt, &c->src2, 1, true);
2868 break;
2869 case Src2One:
2870 c->src2.bytes = 1;
2871 c->src2.val = 1;
2872 break;
2873 case Src2Imm:
2874 rc = decode_imm(ctxt, &c->src2, imm_size(c), true);
2875 break;
2876 }
2877
2878 if (rc != X86EMUL_CONTINUE)
2879 goto done;
2880
2881 /* Decode and fetch the destination operand: register or memory. */
2882 switch (c->d & DstMask) {
2883 case DstReg:
2884 decode_register_operand(&c->dst, c,
2885 c->twobyte && (c->b == 0xb6 || c->b == 0xb7));
2886 break;
2887 case DstImmUByte:
2888 c->dst.type = OP_IMM;
2889 c->dst.addr.mem.ea = c->eip;
2890 c->dst.bytes = 1;
2891 c->dst.val = insn_fetch(u8, 1, c->eip);
2892 break;
2893 case DstMem:
2894 case DstMem64:
2895 c->dst = memop;
2896 if ((c->d & DstMask) == DstMem64)
2897 c->dst.bytes = 8;
2898 else
2899 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
2900 if (c->d & BitOp)
2901 fetch_bit_operand(c);
2902 c->dst.orig_val = c->dst.val;
2903 break;
2904 case DstAcc:
2905 c->dst.type = OP_REG;
2906 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
2907 c->dst.addr.reg = &c->regs[VCPU_REGS_RAX];
2908 fetch_register_operand(&c->dst);
2909 c->dst.orig_val = c->dst.val;
2910 break;
2911 case DstDI:
2912 c->dst.type = OP_MEM;
2913 c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
2914 c->dst.addr.mem.ea =
2915 register_address(c, c->regs[VCPU_REGS_RDI]);
2916 c->dst.addr.mem.seg = VCPU_SREG_ES;
2917 c->dst.val = 0;
2918 break;
2919 case ImplicitOps:
2920 /* Special instructions do their own operand decoding. */
2921 default:
2922 c->dst.type = OP_NONE; /* Disable writeback. */
2923 return 0;
2924 }
2925
2926 done:
2927 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
2928 }
2929
2930 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
2931 {
2932 struct decode_cache *c = &ctxt->decode;
2933
2934 /* The second termination condition only applies for REPE
2935 * and REPNE. Test if the repeat string operation prefix is
2936 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
2937 * corresponding termination condition according to:
2938 * - if REPE/REPZ and ZF = 0 then done
2939 * - if REPNE/REPNZ and ZF = 1 then done
2940 */
2941 if (((c->b == 0xa6) || (c->b == 0xa7) ||
2942 (c->b == 0xae) || (c->b == 0xaf))
2943 && (((c->rep_prefix == REPE_PREFIX) &&
2944 ((ctxt->eflags & EFLG_ZF) == 0))
2945 || ((c->rep_prefix == REPNE_PREFIX) &&
2946 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
2947 return true;
2948
2949 return false;
2950 }
2951
2952 int
2953 x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
2954 {
2955 struct x86_emulate_ops *ops = ctxt->ops;
2956 u64 msr_data;
2957 struct decode_cache *c = &ctxt->decode;
2958 int rc = X86EMUL_CONTINUE;
2959 int saved_dst_type = c->dst.type;
2960 int irq; /* Used for int 3, int, and into */
2961
2962 ctxt->decode.mem_read.pos = 0;
2963
2964 if (ctxt->mode == X86EMUL_MODE_PROT64 && (c->d & No64)) {
2965 rc = emulate_ud(ctxt);
2966 goto done;
2967 }
2968
2969 /* LOCK prefix is allowed only with some instructions */
2970 if (c->lock_prefix && (!(c->d & Lock) || c->dst.type != OP_MEM)) {
2971 rc = emulate_ud(ctxt);
2972 goto done;
2973 }
2974
2975 if ((c->d & SrcMask) == SrcMemFAddr && c->src.type != OP_MEM) {
2976 rc = emulate_ud(ctxt);
2977 goto done;
2978 }
2979
2980 /* Privileged instruction can be executed only in CPL=0 */
2981 if ((c->d & Priv) && ops->cpl(ctxt->vcpu)) {
2982 rc = emulate_gp(ctxt, 0);
2983 goto done;
2984 }
2985
2986 if (c->rep_prefix && (c->d & String)) {
2987 /* All REP prefixes have the same first termination condition */
2988 if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0) {
2989 ctxt->eip = c->eip;
2990 goto done;
2991 }
2992 }
2993
2994 if ((c->src.type == OP_MEM) && !(c->d & NoAccess)) {
2995 rc = read_emulated(ctxt, ops, linear(ctxt, c->src.addr.mem),
2996 c->src.valptr, c->src.bytes);
2997 if (rc != X86EMUL_CONTINUE)
2998 goto done;
2999 c->src.orig_val64 = c->src.val64;
3000 }
3001
3002 if (c->src2.type == OP_MEM) {
3003 rc = read_emulated(ctxt, ops, linear(ctxt, c->src2.addr.mem),
3004 &c->src2.val, c->src2.bytes);
3005 if (rc != X86EMUL_CONTINUE)
3006 goto done;
3007 }
3008
3009 if ((c->d & DstMask) == ImplicitOps)
3010 goto special_insn;
3011
3012
3013 if ((c->dst.type == OP_MEM) && !(c->d & Mov)) {
3014 /* optimisation - avoid slow emulated read if Mov */
3015 rc = read_emulated(ctxt, ops, linear(ctxt, c->dst.addr.mem),
3016 &c->dst.val, c->dst.bytes);
3017 if (rc != X86EMUL_CONTINUE)
3018 goto done;
3019 }
3020 c->dst.orig_val = c->dst.val;
3021
3022 special_insn:
3023
3024 if (c->execute) {
3025 rc = c->execute(ctxt);
3026 if (rc != X86EMUL_CONTINUE)
3027 goto done;
3028 goto writeback;
3029 }
3030
3031 if (c->twobyte)
3032 goto twobyte_insn;
3033
3034 switch (c->b) {
3035 case 0x00 ... 0x05:
3036 add: /* add */
3037 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags);
3038 break;
3039 case 0x06: /* push es */
3040 emulate_push_sreg(ctxt, ops, VCPU_SREG_ES);
3041 break;
3042 case 0x07: /* pop es */
3043 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_ES);
3044 break;
3045 case 0x08 ... 0x0d:
3046 or: /* or */
3047 emulate_2op_SrcV("or", c->src, c->dst, ctxt->eflags);
3048 break;
3049 case 0x0e: /* push cs */
3050 emulate_push_sreg(ctxt, ops, VCPU_SREG_CS);
3051 break;
3052 case 0x10 ... 0x15:
3053 adc: /* adc */
3054 emulate_2op_SrcV("adc", c->src, c->dst, ctxt->eflags);
3055 break;
3056 case 0x16: /* push ss */
3057 emulate_push_sreg(ctxt, ops, VCPU_SREG_SS);
3058 break;
3059 case 0x17: /* pop ss */
3060 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_SS);
3061 break;
3062 case 0x18 ... 0x1d:
3063 sbb: /* sbb */
3064 emulate_2op_SrcV("sbb", c->src, c->dst, ctxt->eflags);
3065 break;
3066 case 0x1e: /* push ds */
3067 emulate_push_sreg(ctxt, ops, VCPU_SREG_DS);
3068 break;
3069 case 0x1f: /* pop ds */
3070 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_DS);
3071 break;
3072 case 0x20 ... 0x25:
3073 and: /* and */
3074 emulate_2op_SrcV("and", c->src, c->dst, ctxt->eflags);
3075 break;
3076 case 0x28 ... 0x2d:
3077 sub: /* sub */
3078 emulate_2op_SrcV("sub", c->src, c->dst, ctxt->eflags);
3079 break;
3080 case 0x30 ... 0x35:
3081 xor: /* xor */
3082 emulate_2op_SrcV("xor", c->src, c->dst, ctxt->eflags);
3083 break;
3084 case 0x38 ... 0x3d:
3085 cmp: /* cmp */
3086 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
3087 break;
3088 case 0x40 ... 0x47: /* inc r16/r32 */
3089 emulate_1op("inc", c->dst, ctxt->eflags);
3090 break;
3091 case 0x48 ... 0x4f: /* dec r16/r32 */
3092 emulate_1op("dec", c->dst, ctxt->eflags);
3093 break;
3094 case 0x58 ... 0x5f: /* pop reg */
3095 pop_instruction:
3096 rc = emulate_pop(ctxt, ops, &c->dst.val, c->op_bytes);
3097 break;
3098 case 0x60: /* pusha */
3099 rc = emulate_pusha(ctxt, ops);
3100 break;
3101 case 0x61: /* popa */
3102 rc = emulate_popa(ctxt, ops);
3103 break;
3104 case 0x63: /* movsxd */
3105 if (ctxt->mode != X86EMUL_MODE_PROT64)
3106 goto cannot_emulate;
3107 c->dst.val = (s32) c->src.val;
3108 break;
3109 case 0x6c: /* insb */
3110 case 0x6d: /* insw/insd */
3111 c->src.val = c->regs[VCPU_REGS_RDX];
3112 goto do_io_in;
3113 case 0x6e: /* outsb */
3114 case 0x6f: /* outsw/outsd */
3115 c->dst.val = c->regs[VCPU_REGS_RDX];
3116 goto do_io_out;
3117 break;
3118 case 0x70 ... 0x7f: /* jcc (short) */
3119 if (test_cc(c->b, ctxt->eflags))
3120 jmp_rel(c, c->src.val);
3121 break;
3122 case 0x80 ... 0x83: /* Grp1 */
3123 switch (c->modrm_reg) {
3124 case 0:
3125 goto add;
3126 case 1:
3127 goto or;
3128 case 2:
3129 goto adc;
3130 case 3:
3131 goto sbb;
3132 case 4:
3133 goto and;
3134 case 5:
3135 goto sub;
3136 case 6:
3137 goto xor;
3138 case 7:
3139 goto cmp;
3140 }
3141 break;
3142 case 0x84 ... 0x85:
3143 test:
3144 emulate_2op_SrcV("test", c->src, c->dst, ctxt->eflags);
3145 break;
3146 case 0x86 ... 0x87: /* xchg */
3147 xchg:
3148 /* Write back the register source. */
3149 c->src.val = c->dst.val;
3150 write_register_operand(&c->src);
3151 /*
3152 * Write back the memory destination with implicit LOCK
3153 * prefix.
3154 */
3155 c->dst.val = c->src.orig_val;
3156 c->lock_prefix = 1;
3157 break;
3158 case 0x8c: /* mov r/m, sreg */
3159 if (c->modrm_reg > VCPU_SREG_GS) {
3160 rc = emulate_ud(ctxt);
3161 goto done;
3162 }
3163 c->dst.val = ops->get_segment_selector(c->modrm_reg, ctxt->vcpu);
3164 break;
3165 case 0x8d: /* lea r16/r32, m */
3166 c->dst.val = c->src.addr.mem.ea;
3167 break;
3168 case 0x8e: { /* mov seg, r/m16 */
3169 uint16_t sel;
3170
3171 sel = c->src.val;
3172
3173 if (c->modrm_reg == VCPU_SREG_CS ||
3174 c->modrm_reg > VCPU_SREG_GS) {
3175 rc = emulate_ud(ctxt);
3176 goto done;
3177 }
3178
3179 if (c->modrm_reg == VCPU_SREG_SS)
3180 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
3181
3182 rc = load_segment_descriptor(ctxt, ops, sel, c->modrm_reg);
3183
3184 c->dst.type = OP_NONE; /* Disable writeback. */
3185 break;
3186 }
3187 case 0x8f: /* pop (sole member of Grp1a) */
3188 rc = emulate_grp1a(ctxt, ops);
3189 break;
3190 case 0x90 ... 0x97: /* nop / xchg reg, rax */
3191 if (c->dst.addr.reg == &c->regs[VCPU_REGS_RAX])
3192 break;
3193 goto xchg;
3194 case 0x98: /* cbw/cwde/cdqe */
3195 switch (c->op_bytes) {
3196 case 2: c->dst.val = (s8)c->dst.val; break;
3197 case 4: c->dst.val = (s16)c->dst.val; break;
3198 case 8: c->dst.val = (s32)c->dst.val; break;
3199 }
3200 break;
3201 case 0x9c: /* pushf */
3202 c->src.val = (unsigned long) ctxt->eflags;
3203 emulate_push(ctxt, ops);
3204 break;
3205 case 0x9d: /* popf */
3206 c->dst.type = OP_REG;
3207 c->dst.addr.reg = &ctxt->eflags;
3208 c->dst.bytes = c->op_bytes;
3209 rc = emulate_popf(ctxt, ops, &c->dst.val, c->op_bytes);
3210 break;
3211 case 0xa6 ... 0xa7: /* cmps */
3212 c->dst.type = OP_NONE; /* Disable writeback. */
3213 goto cmp;
3214 case 0xa8 ... 0xa9: /* test ax, imm */
3215 goto test;
3216 case 0xae ... 0xaf: /* scas */
3217 goto cmp;
3218 case 0xc0 ... 0xc1:
3219 emulate_grp2(ctxt);
3220 break;
3221 case 0xc3: /* ret */
3222 c->dst.type = OP_REG;
3223 c->dst.addr.reg = &c->eip;
3224 c->dst.bytes = c->op_bytes;
3225 goto pop_instruction;
3226 case 0xc4: /* les */
3227 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_ES);
3228 break;
3229 case 0xc5: /* lds */
3230 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_DS);
3231 break;
3232 case 0xcb: /* ret far */
3233 rc = emulate_ret_far(ctxt, ops);
3234 break;
3235 case 0xcc: /* int3 */
3236 irq = 3;
3237 goto do_interrupt;
3238 case 0xcd: /* int n */
3239 irq = c->src.val;
3240 do_interrupt:
3241 rc = emulate_int(ctxt, ops, irq);
3242 break;
3243 case 0xce: /* into */
3244 if (ctxt->eflags & EFLG_OF) {
3245 irq = 4;
3246 goto do_interrupt;
3247 }
3248 break;
3249 case 0xcf: /* iret */
3250 rc = emulate_iret(ctxt, ops);
3251 break;
3252 case 0xd0 ... 0xd1: /* Grp2 */
3253 emulate_grp2(ctxt);
3254 break;
3255 case 0xd2 ... 0xd3: /* Grp2 */
3256 c->src.val = c->regs[VCPU_REGS_RCX];
3257 emulate_grp2(ctxt);
3258 break;
3259 case 0xe0 ... 0xe2: /* loop/loopz/loopnz */
3260 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
3261 if (address_mask(c, c->regs[VCPU_REGS_RCX]) != 0 &&
3262 (c->b == 0xe2 || test_cc(c->b ^ 0x5, ctxt->eflags)))
3263 jmp_rel(c, c->src.val);
3264 break;
3265 case 0xe3: /* jcxz/jecxz/jrcxz */
3266 if (address_mask(c, c->regs[VCPU_REGS_RCX]) == 0)
3267 jmp_rel(c, c->src.val);
3268 break;
3269 case 0xe4: /* inb */
3270 case 0xe5: /* in */
3271 goto do_io_in;
3272 case 0xe6: /* outb */
3273 case 0xe7: /* out */
3274 goto do_io_out;
3275 case 0xe8: /* call (near) */ {
3276 long int rel = c->src.val;
3277 c->src.val = (unsigned long) c->eip;
3278 jmp_rel(c, rel);
3279 emulate_push(ctxt, ops);
3280 break;
3281 }
3282 case 0xe9: /* jmp rel */
3283 goto jmp;
3284 case 0xea: { /* jmp far */
3285 unsigned short sel;
3286 jump_far:
3287 memcpy(&sel, c->src.valptr + c->op_bytes, 2);
3288
3289 if (load_segment_descriptor(ctxt, ops, sel, VCPU_SREG_CS))
3290 goto done;
3291
3292 c->eip = 0;
3293 memcpy(&c->eip, c->src.valptr, c->op_bytes);
3294 break;
3295 }
3296 case 0xeb:
3297 jmp: /* jmp rel short */
3298 jmp_rel(c, c->src.val);
3299 c->dst.type = OP_NONE; /* Disable writeback. */
3300 break;
3301 case 0xec: /* in al,dx */
3302 case 0xed: /* in (e/r)ax,dx */
3303 c->src.val = c->regs[VCPU_REGS_RDX];
3304 do_io_in:
3305 c->dst.bytes = min(c->dst.bytes, 4u);
3306 if (!emulator_io_permited(ctxt, ops, c->src.val, c->dst.bytes)) {
3307 rc = emulate_gp(ctxt, 0);
3308 goto done;
3309 }
3310 if (!pio_in_emulated(ctxt, ops, c->dst.bytes, c->src.val,
3311 &c->dst.val))
3312 goto done; /* IO is needed */
3313 break;
3314 case 0xee: /* out dx,al */
3315 case 0xef: /* out dx,(e/r)ax */
3316 c->dst.val = c->regs[VCPU_REGS_RDX];
3317 do_io_out:
3318 c->src.bytes = min(c->src.bytes, 4u);
3319 if (!emulator_io_permited(ctxt, ops, c->dst.val,
3320 c->src.bytes)) {
3321 rc = emulate_gp(ctxt, 0);
3322 goto done;
3323 }
3324 ops->pio_out_emulated(c->src.bytes, c->dst.val,
3325 &c->src.val, 1, ctxt->vcpu);
3326 c->dst.type = OP_NONE; /* Disable writeback. */
3327 break;
3328 case 0xf4: /* hlt */
3329 ctxt->vcpu->arch.halt_request = 1;
3330 break;
3331 case 0xf5: /* cmc */
3332 /* complement carry flag from eflags reg */
3333 ctxt->eflags ^= EFLG_CF;
3334 break;
3335 case 0xf6 ... 0xf7: /* Grp3 */
3336 rc = emulate_grp3(ctxt, ops);
3337 break;
3338 case 0xf8: /* clc */
3339 ctxt->eflags &= ~EFLG_CF;
3340 break;
3341 case 0xf9: /* stc */
3342 ctxt->eflags |= EFLG_CF;
3343 break;
3344 case 0xfa: /* cli */
3345 if (emulator_bad_iopl(ctxt, ops)) {
3346 rc = emulate_gp(ctxt, 0);
3347 goto done;
3348 } else
3349 ctxt->eflags &= ~X86_EFLAGS_IF;
3350 break;
3351 case 0xfb: /* sti */
3352 if (emulator_bad_iopl(ctxt, ops)) {
3353 rc = emulate_gp(ctxt, 0);
3354 goto done;
3355 } else {
3356 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
3357 ctxt->eflags |= X86_EFLAGS_IF;
3358 }
3359 break;
3360 case 0xfc: /* cld */
3361 ctxt->eflags &= ~EFLG_DF;
3362 break;
3363 case 0xfd: /* std */
3364 ctxt->eflags |= EFLG_DF;
3365 break;
3366 case 0xfe: /* Grp4 */
3367 grp45:
3368 rc = emulate_grp45(ctxt, ops);
3369 break;
3370 case 0xff: /* Grp5 */
3371 if (c->modrm_reg == 5)
3372 goto jump_far;
3373 goto grp45;
3374 default:
3375 goto cannot_emulate;
3376 }
3377
3378 if (rc != X86EMUL_CONTINUE)
3379 goto done;
3380
3381 writeback:
3382 rc = writeback(ctxt, ops);
3383 if (rc != X86EMUL_CONTINUE)
3384 goto done;
3385
3386 /*
3387 * restore dst type in case the decoding will be reused
3388 * (happens for string instruction )
3389 */
3390 c->dst.type = saved_dst_type;
3391
3392 if ((c->d & SrcMask) == SrcSI)
3393 string_addr_inc(ctxt, seg_override(ctxt, ops, c),
3394 VCPU_REGS_RSI, &c->src);
3395
3396 if ((c->d & DstMask) == DstDI)
3397 string_addr_inc(ctxt, VCPU_SREG_ES, VCPU_REGS_RDI,
3398 &c->dst);
3399
3400 if (c->rep_prefix && (c->d & String)) {
3401 struct read_cache *r = &ctxt->decode.io_read;
3402 register_address_increment(c, &c->regs[VCPU_REGS_RCX], -1);
3403
3404 if (!string_insn_completed(ctxt)) {
3405 /*
3406 * Re-enter guest when pio read ahead buffer is empty
3407 * or, if it is not used, after each 1024 iteration.
3408 */
3409 if ((r->end != 0 || c->regs[VCPU_REGS_RCX] & 0x3ff) &&
3410 (r->end == 0 || r->end != r->pos)) {
3411 /*
3412 * Reset read cache. Usually happens before
3413 * decode, but since instruction is restarted
3414 * we have to do it here.
3415 */
3416 ctxt->decode.mem_read.end = 0;
3417 return EMULATION_RESTART;
3418 }
3419 goto done; /* skip rip writeback */
3420 }
3421 }
3422
3423 ctxt->eip = c->eip;
3424
3425 done:
3426 if (rc == X86EMUL_PROPAGATE_FAULT)
3427 ctxt->have_exception = true;
3428 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
3429
3430 twobyte_insn:
3431 switch (c->b) {
3432 case 0x01: /* lgdt, lidt, lmsw */
3433 switch (c->modrm_reg) {
3434 u16 size;
3435 unsigned long address;
3436
3437 case 0: /* vmcall */
3438 if (c->modrm_mod != 3 || c->modrm_rm != 1)
3439 goto cannot_emulate;
3440
3441 rc = kvm_fix_hypercall(ctxt->vcpu);
3442 if (rc != X86EMUL_CONTINUE)
3443 goto done;
3444
3445 /* Let the processor re-execute the fixed hypercall */
3446 c->eip = ctxt->eip;
3447 /* Disable writeback. */
3448 c->dst.type = OP_NONE;
3449 break;
3450 case 2: /* lgdt */
3451 rc = read_descriptor(ctxt, ops, c->src.addr.mem,
3452 &size, &address, c->op_bytes);
3453 if (rc != X86EMUL_CONTINUE)
3454 goto done;
3455 realmode_lgdt(ctxt->vcpu, size, address);
3456 /* Disable writeback. */
3457 c->dst.type = OP_NONE;
3458 break;
3459 case 3: /* lidt/vmmcall */
3460 if (c->modrm_mod == 3) {
3461 switch (c->modrm_rm) {
3462 case 1:
3463 rc = kvm_fix_hypercall(ctxt->vcpu);
3464 break;
3465 default:
3466 goto cannot_emulate;
3467 }
3468 } else {
3469 rc = read_descriptor(ctxt, ops, c->src.addr.mem,
3470 &size, &address,
3471 c->op_bytes);
3472 if (rc != X86EMUL_CONTINUE)
3473 goto done;
3474 realmode_lidt(ctxt->vcpu, size, address);
3475 }
3476 /* Disable writeback. */
3477 c->dst.type = OP_NONE;
3478 break;
3479 case 4: /* smsw */
3480 c->dst.bytes = 2;
3481 c->dst.val = ops->get_cr(0, ctxt->vcpu);
3482 break;
3483 case 6: /* lmsw */
3484 ops->set_cr(0, (ops->get_cr(0, ctxt->vcpu) & ~0x0eul) |
3485 (c->src.val & 0x0f), ctxt->vcpu);
3486 c->dst.type = OP_NONE;
3487 break;
3488 case 5: /* not defined */
3489 emulate_ud(ctxt);
3490 rc = X86EMUL_PROPAGATE_FAULT;
3491 goto done;
3492 case 7: /* invlpg*/
3493 emulate_invlpg(ctxt->vcpu,
3494 linear(ctxt, c->src.addr.mem));
3495 /* Disable writeback. */
3496 c->dst.type = OP_NONE;
3497 break;
3498 default:
3499 goto cannot_emulate;
3500 }
3501 break;
3502 case 0x05: /* syscall */
3503 rc = emulate_syscall(ctxt, ops);
3504 break;
3505 case 0x06:
3506 emulate_clts(ctxt->vcpu);
3507 break;
3508 case 0x09: /* wbinvd */
3509 kvm_emulate_wbinvd(ctxt->vcpu);
3510 break;
3511 case 0x08: /* invd */
3512 case 0x0d: /* GrpP (prefetch) */
3513 case 0x18: /* Grp16 (prefetch/nop) */
3514 break;
3515 case 0x20: /* mov cr, reg */
3516 switch (c->modrm_reg) {
3517 case 1:
3518 case 5 ... 7:
3519 case 9 ... 15:
3520 emulate_ud(ctxt);
3521 rc = X86EMUL_PROPAGATE_FAULT;
3522 goto done;
3523 }
3524 c->dst.val = ops->get_cr(c->modrm_reg, ctxt->vcpu);
3525 break;
3526 case 0x21: /* mov from dr to reg */
3527 if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
3528 (c->modrm_reg == 4 || c->modrm_reg == 5)) {
3529 emulate_ud(ctxt);
3530 rc = X86EMUL_PROPAGATE_FAULT;
3531 goto done;
3532 }
3533 ops->get_dr(c->modrm_reg, &c->dst.val, ctxt->vcpu);
3534 break;
3535 case 0x22: /* mov reg, cr */
3536 if (ops->set_cr(c->modrm_reg, c->src.val, ctxt->vcpu)) {
3537 emulate_gp(ctxt, 0);
3538 rc = X86EMUL_PROPAGATE_FAULT;
3539 goto done;
3540 }
3541 c->dst.type = OP_NONE;
3542 break;
3543 case 0x23: /* mov from reg to dr */
3544 if ((ops->get_cr(4, ctxt->vcpu) & X86_CR4_DE) &&
3545 (c->modrm_reg == 4 || c->modrm_reg == 5)) {
3546 emulate_ud(ctxt);
3547 rc = X86EMUL_PROPAGATE_FAULT;
3548 goto done;
3549 }
3550
3551 if (ops->set_dr(c->modrm_reg, c->src.val &
3552 ((ctxt->mode == X86EMUL_MODE_PROT64) ?
3553 ~0ULL : ~0U), ctxt->vcpu) < 0) {
3554 /* #UD condition is already handled by the code above */
3555 emulate_gp(ctxt, 0);
3556 rc = X86EMUL_PROPAGATE_FAULT;
3557 goto done;
3558 }
3559
3560 c->dst.type = OP_NONE; /* no writeback */
3561 break;
3562 case 0x30:
3563 /* wrmsr */
3564 msr_data = (u32)c->regs[VCPU_REGS_RAX]
3565 | ((u64)c->regs[VCPU_REGS_RDX] << 32);
3566 if (ops->set_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], msr_data)) {
3567 emulate_gp(ctxt, 0);
3568 rc = X86EMUL_PROPAGATE_FAULT;
3569 goto done;
3570 }
3571 rc = X86EMUL_CONTINUE;
3572 break;
3573 case 0x32:
3574 /* rdmsr */
3575 if (ops->get_msr(ctxt->vcpu, c->regs[VCPU_REGS_RCX], &msr_data)) {
3576 emulate_gp(ctxt, 0);
3577 rc = X86EMUL_PROPAGATE_FAULT;
3578 goto done;
3579 } else {
3580 c->regs[VCPU_REGS_RAX] = (u32)msr_data;
3581 c->regs[VCPU_REGS_RDX] = msr_data >> 32;
3582 }
3583 rc = X86EMUL_CONTINUE;
3584 break;
3585 case 0x34: /* sysenter */
3586 rc = emulate_sysenter(ctxt, ops);
3587 break;
3588 case 0x35: /* sysexit */
3589 rc = emulate_sysexit(ctxt, ops);
3590 break;
3591 case 0x40 ... 0x4f: /* cmov */
3592 c->dst.val = c->dst.orig_val = c->src.val;
3593 if (!test_cc(c->b, ctxt->eflags))
3594 c->dst.type = OP_NONE; /* no writeback */
3595 break;
3596 case 0x80 ... 0x8f: /* jnz rel, etc*/
3597 if (test_cc(c->b, ctxt->eflags))
3598 jmp_rel(c, c->src.val);
3599 break;
3600 case 0x90 ... 0x9f: /* setcc r/m8 */
3601 c->dst.val = test_cc(c->b, ctxt->eflags);
3602 break;
3603 case 0xa0: /* push fs */
3604 emulate_push_sreg(ctxt, ops, VCPU_SREG_FS);
3605 break;
3606 case 0xa1: /* pop fs */
3607 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_FS);
3608 break;
3609 case 0xa3:
3610 bt: /* bt */
3611 c->dst.type = OP_NONE;
3612 /* only subword offset */
3613 c->src.val &= (c->dst.bytes << 3) - 1;
3614 emulate_2op_SrcV_nobyte("bt", c->src, c->dst, ctxt->eflags);
3615 break;
3616 case 0xa4: /* shld imm8, r, r/m */
3617 case 0xa5: /* shld cl, r, r/m */
3618 emulate_2op_cl("shld", c->src2, c->src, c->dst, ctxt->eflags);
3619 break;
3620 case 0xa8: /* push gs */
3621 emulate_push_sreg(ctxt, ops, VCPU_SREG_GS);
3622 break;
3623 case 0xa9: /* pop gs */
3624 rc = emulate_pop_sreg(ctxt, ops, VCPU_SREG_GS);
3625 break;
3626 case 0xab:
3627 bts: /* bts */
3628 emulate_2op_SrcV_nobyte("bts", c->src, c->dst, ctxt->eflags);
3629 break;
3630 case 0xac: /* shrd imm8, r, r/m */
3631 case 0xad: /* shrd cl, r, r/m */
3632 emulate_2op_cl("shrd", c->src2, c->src, c->dst, ctxt->eflags);
3633 break;
3634 case 0xae: /* clflush */
3635 break;
3636 case 0xb0 ... 0xb1: /* cmpxchg */
3637 /*
3638 * Save real source value, then compare EAX against
3639 * destination.
3640 */
3641 c->src.orig_val = c->src.val;
3642 c->src.val = c->regs[VCPU_REGS_RAX];
3643 emulate_2op_SrcV("cmp", c->src, c->dst, ctxt->eflags);
3644 if (ctxt->eflags & EFLG_ZF) {
3645 /* Success: write back to memory. */
3646 c->dst.val = c->src.orig_val;
3647 } else {
3648 /* Failure: write the value we saw to EAX. */
3649 c->dst.type = OP_REG;
3650 c->dst.addr.reg = (unsigned long *)&c->regs[VCPU_REGS_RAX];
3651 }
3652 break;
3653 case 0xb2: /* lss */
3654 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_SS);
3655 break;
3656 case 0xb3:
3657 btr: /* btr */
3658 emulate_2op_SrcV_nobyte("btr", c->src, c->dst, ctxt->eflags);
3659 break;
3660 case 0xb4: /* lfs */
3661 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_FS);
3662 break;
3663 case 0xb5: /* lgs */
3664 rc = emulate_load_segment(ctxt, ops, VCPU_SREG_GS);
3665 break;
3666 case 0xb6 ... 0xb7: /* movzx */
3667 c->dst.bytes = c->op_bytes;
3668 c->dst.val = (c->d & ByteOp) ? (u8) c->src.val
3669 : (u16) c->src.val;
3670 break;
3671 case 0xba: /* Grp8 */
3672 switch (c->modrm_reg & 3) {
3673 case 0:
3674 goto bt;
3675 case 1:
3676 goto bts;
3677 case 2:
3678 goto btr;
3679 case 3:
3680 goto btc;
3681 }
3682 break;
3683 case 0xbb:
3684 btc: /* btc */
3685 emulate_2op_SrcV_nobyte("btc", c->src, c->dst, ctxt->eflags);
3686 break;
3687 case 0xbc: { /* bsf */
3688 u8 zf;
3689 __asm__ ("bsf %2, %0; setz %1"
3690 : "=r"(c->dst.val), "=q"(zf)
3691 : "r"(c->src.val));
3692 ctxt->eflags &= ~X86_EFLAGS_ZF;
3693 if (zf) {
3694 ctxt->eflags |= X86_EFLAGS_ZF;
3695 c->dst.type = OP_NONE; /* Disable writeback. */
3696 }
3697 break;
3698 }
3699 case 0xbd: { /* bsr */
3700 u8 zf;
3701 __asm__ ("bsr %2, %0; setz %1"
3702 : "=r"(c->dst.val), "=q"(zf)
3703 : "r"(c->src.val));
3704 ctxt->eflags &= ~X86_EFLAGS_ZF;
3705 if (zf) {
3706 ctxt->eflags |= X86_EFLAGS_ZF;
3707 c->dst.type = OP_NONE; /* Disable writeback. */
3708 }
3709 break;
3710 }
3711 case 0xbe ... 0xbf: /* movsx */
3712 c->dst.bytes = c->op_bytes;
3713 c->dst.val = (c->d & ByteOp) ? (s8) c->src.val :
3714 (s16) c->src.val;
3715 break;
3716 case 0xc0 ... 0xc1: /* xadd */
3717 emulate_2op_SrcV("add", c->src, c->dst, ctxt->eflags);
3718 /* Write back the register source. */
3719 c->src.val = c->dst.orig_val;
3720 write_register_operand(&c->src);
3721 break;
3722 case 0xc3: /* movnti */
3723 c->dst.bytes = c->op_bytes;
3724 c->dst.val = (c->op_bytes == 4) ? (u32) c->src.val :
3725 (u64) c->src.val;
3726 break;
3727 case 0xc7: /* Grp9 (cmpxchg8b) */
3728 rc = emulate_grp9(ctxt, ops);
3729 break;
3730 default:
3731 goto cannot_emulate;
3732 }
3733
3734 if (rc != X86EMUL_CONTINUE)
3735 goto done;
3736
3737 goto writeback;
3738
3739 cannot_emulate:
3740 return -1;
3741 }
Linux kernel - Deliverables
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