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Merge tag 'v3.3.7' into 3.3/master
[zen-stable.git] / arch / x86 / kvm / emulate.c
blob0982507b962a736f3e643d454d4b38c2b1cd1c29
1 /******************************************************************************
2 * emulate.c
3 *
4 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator.
5 *
6 * Copyright (c) 2005 Keir Fraser
7 *
8 * Linux coding style, mod r/m decoder, segment base fixes, real-mode
9 * privileged instructions:
10 *
11 * Copyright (C) 2006 Qumranet
12 * Copyright 2010 Red Hat, Inc. and/or its affiliates.
13 *
14 * Avi Kivity <avi@qumranet.com>
15 * Yaniv Kamay <yaniv@qumranet.com>
16 *
17 * This work is licensed under the terms of the GNU GPL, version 2. See
18 * the COPYING file in the top-level directory.
19 *
20 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
21 */
22
23 #include <linux/kvm_host.h>
24 #include "kvm_cache_regs.h"
25 #include <linux/module.h>
26 #include <asm/kvm_emulate.h>
27
28 #include "x86.h"
29 #include "tss.h"
30
31 /*
32 * Operand types
33 */
34 #define OpNone 0ull
35 #define OpImplicit 1ull /* No generic decode */
36 #define OpReg 2ull /* Register */
37 #define OpMem 3ull /* Memory */
38 #define OpAcc 4ull /* Accumulator: AL/AX/EAX/RAX */
39 #define OpDI 5ull /* ES:DI/EDI/RDI */
40 #define OpMem64 6ull /* Memory, 64-bit */
41 #define OpImmUByte 7ull /* Zero-extended 8-bit immediate */
42 #define OpDX 8ull /* DX register */
43 #define OpCL 9ull /* CL register (for shifts) */
44 #define OpImmByte 10ull /* 8-bit sign extended immediate */
45 #define OpOne 11ull /* Implied 1 */
46 #define OpImm 12ull /* Sign extended immediate */
47 #define OpMem16 13ull /* Memory operand (16-bit). */
48 #define OpMem32 14ull /* Memory operand (32-bit). */
49 #define OpImmU 15ull /* Immediate operand, zero extended */
50 #define OpSI 16ull /* SI/ESI/RSI */
51 #define OpImmFAddr 17ull /* Immediate far address */
52 #define OpMemFAddr 18ull /* Far address in memory */
53 #define OpImmU16 19ull /* Immediate operand, 16 bits, zero extended */
54 #define OpES 20ull /* ES */
55 #define OpCS 21ull /* CS */
56 #define OpSS 22ull /* SS */
57 #define OpDS 23ull /* DS */
58 #define OpFS 24ull /* FS */
59 #define OpGS 25ull /* GS */
60
61 #define OpBits 5 /* Width of operand field */
62 #define OpMask ((1ull << OpBits) - 1)
63
64 /*
65 * Opcode effective-address decode tables.
66 * Note that we only emulate instructions that have at least one memory
67 * operand (excluding implicit stack references). We assume that stack
68 * references and instruction fetches will never occur in special memory
69 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
70 * not be handled.
71 */
72
73 /* Operand sizes: 8-bit operands or specified/overridden size. */
74 #define ByteOp (1<<0) /* 8-bit operands. */
75 /* Destination operand type. */
76 #define DstShift 1
77 #define ImplicitOps (OpImplicit << DstShift)
78 #define DstReg (OpReg << DstShift)
79 #define DstMem (OpMem << DstShift)
80 #define DstAcc (OpAcc << DstShift)
81 #define DstDI (OpDI << DstShift)
82 #define DstMem64 (OpMem64 << DstShift)
83 #define DstImmUByte (OpImmUByte << DstShift)
84 #define DstDX (OpDX << DstShift)
85 #define DstMask (OpMask << DstShift)
86 /* Source operand type. */
87 #define SrcShift 6
88 #define SrcNone (OpNone << SrcShift)
89 #define SrcReg (OpReg << SrcShift)
90 #define SrcMem (OpMem << SrcShift)
91 #define SrcMem16 (OpMem16 << SrcShift)
92 #define SrcMem32 (OpMem32 << SrcShift)
93 #define SrcImm (OpImm << SrcShift)
94 #define SrcImmByte (OpImmByte << SrcShift)
95 #define SrcOne (OpOne << SrcShift)
96 #define SrcImmUByte (OpImmUByte << SrcShift)
97 #define SrcImmU (OpImmU << SrcShift)
98 #define SrcSI (OpSI << SrcShift)
99 #define SrcImmFAddr (OpImmFAddr << SrcShift)
100 #define SrcMemFAddr (OpMemFAddr << SrcShift)
101 #define SrcAcc (OpAcc << SrcShift)
102 #define SrcImmU16 (OpImmU16 << SrcShift)
103 #define SrcDX (OpDX << SrcShift)
104 #define SrcMask (OpMask << SrcShift)
105 #define BitOp (1<<11)
106 #define MemAbs (1<<12) /* Memory operand is absolute displacement */
107 #define String (1<<13) /* String instruction (rep capable) */
108 #define Stack (1<<14) /* Stack instruction (push/pop) */
109 #define GroupMask (7<<15) /* Opcode uses one of the group mechanisms */
110 #define Group (1<<15) /* Bits 3:5 of modrm byte extend opcode */
111 #define GroupDual (2<<15) /* Alternate decoding of mod == 3 */
112 #define Prefix (3<<15) /* Instruction varies with 66/f2/f3 prefix */
113 #define RMExt (4<<15) /* Opcode extension in ModRM r/m if mod == 3 */
114 #define Sse (1<<18) /* SSE Vector instruction */
115 /* Generic ModRM decode. */
116 #define ModRM (1<<19)
117 /* Destination is only written; never read. */
118 #define Mov (1<<20)
119 /* Misc flags */
120 #define Prot (1<<21) /* instruction generates #UD if not in prot-mode */
121 #define VendorSpecific (1<<22) /* Vendor specific instruction */
122 #define NoAccess (1<<23) /* Don't access memory (lea/invlpg/verr etc) */
123 #define Op3264 (1<<24) /* Operand is 64b in long mode, 32b otherwise */
124 #define Undefined (1<<25) /* No Such Instruction */
125 #define Lock (1<<26) /* lock prefix is allowed for the instruction */
126 #define Priv (1<<27) /* instruction generates #GP if current CPL != 0 */
127 #define No64 (1<<28)
128 #define PageTable (1 << 29) /* instruction used to write page table */
129 /* Source 2 operand type */
130 #define Src2Shift (30)
131 #define Src2None (OpNone << Src2Shift)
132 #define Src2CL (OpCL << Src2Shift)
133 #define Src2ImmByte (OpImmByte << Src2Shift)
134 #define Src2One (OpOne << Src2Shift)
135 #define Src2Imm (OpImm << Src2Shift)
136 #define Src2ES (OpES << Src2Shift)
137 #define Src2CS (OpCS << Src2Shift)
138 #define Src2SS (OpSS << Src2Shift)
139 #define Src2DS (OpDS << Src2Shift)
140 #define Src2FS (OpFS << Src2Shift)
141 #define Src2GS (OpGS << Src2Shift)
142 #define Src2Mask (OpMask << Src2Shift)
143
144 #define X2(x...) x, x
145 #define X3(x...) X2(x), x
146 #define X4(x...) X2(x), X2(x)
147 #define X5(x...) X4(x), x
148 #define X6(x...) X4(x), X2(x)
149 #define X7(x...) X4(x), X3(x)
150 #define X8(x...) X4(x), X4(x)
151 #define X16(x...) X8(x), X8(x)
152
153 struct opcode {
154 u64 flags : 56;
155 u64 intercept : 8;
156 union {
157 int (*execute)(struct x86_emulate_ctxt *ctxt);
158 struct opcode *group;
159 struct group_dual *gdual;
160 struct gprefix *gprefix;
161 } u;
162 int (*check_perm)(struct x86_emulate_ctxt *ctxt);
163 };
164
165 struct group_dual {
166 struct opcode mod012[8];
167 struct opcode mod3[8];
168 };
169
170 struct gprefix {
171 struct opcode pfx_no;
172 struct opcode pfx_66;
173 struct opcode pfx_f2;
174 struct opcode pfx_f3;
175 };
176
177 /* EFLAGS bit definitions. */
178 #define EFLG_ID (1<<21)
179 #define EFLG_VIP (1<<20)
180 #define EFLG_VIF (1<<19)
181 #define EFLG_AC (1<<18)
182 #define EFLG_VM (1<<17)
183 #define EFLG_RF (1<<16)
184 #define EFLG_IOPL (3<<12)
185 #define EFLG_NT (1<<14)
186 #define EFLG_OF (1<<11)
187 #define EFLG_DF (1<<10)
188 #define EFLG_IF (1<<9)
189 #define EFLG_TF (1<<8)
190 #define EFLG_SF (1<<7)
191 #define EFLG_ZF (1<<6)
192 #define EFLG_AF (1<<4)
193 #define EFLG_PF (1<<2)
194 #define EFLG_CF (1<<0)
195
196 #define EFLG_RESERVED_ZEROS_MASK 0xffc0802a
197 #define EFLG_RESERVED_ONE_MASK 2
198
199 /*
200 * Instruction emulation:
201 * Most instructions are emulated directly via a fragment of inline assembly
202 * code. This allows us to save/restore EFLAGS and thus very easily pick up
203 * any modified flags.
204 */
205
206 #if defined(CONFIG_X86_64)
207 #define _LO32 "k" /* force 32-bit operand */
208 #define _STK "%%rsp" /* stack pointer */
209 #elif defined(__i386__)
210 #define _LO32 "" /* force 32-bit operand */
211 #define _STK "%%esp" /* stack pointer */
212 #endif
213
214 /*
215 * These EFLAGS bits are restored from saved value during emulation, and
216 * any changes are written back to the saved value after emulation.
217 */
218 #define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
219
220 /* Before executing instruction: restore necessary bits in EFLAGS. */
221 #define _PRE_EFLAGS(_sav, _msk, _tmp) \
222 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); _sav &= ~_msk; */ \
223 "movl %"_sav",%"_LO32 _tmp"; " \
224 "push %"_tmp"; " \
225 "push %"_tmp"; " \
226 "movl %"_msk",%"_LO32 _tmp"; " \
227 "andl %"_LO32 _tmp",("_STK"); " \
228 "pushf; " \
229 "notl %"_LO32 _tmp"; " \
230 "andl %"_LO32 _tmp",("_STK"); " \
231 "andl %"_LO32 _tmp","__stringify(BITS_PER_LONG/4)"("_STK"); " \
232 "pop %"_tmp"; " \
233 "orl %"_LO32 _tmp",("_STK"); " \
234 "popf; " \
235 "pop %"_sav"; "
236
237 /* After executing instruction: write-back necessary bits in EFLAGS. */
238 #define _POST_EFLAGS(_sav, _msk, _tmp) \
239 /* _sav |= EFLAGS & _msk; */ \
240 "pushf; " \
241 "pop %"_tmp"; " \
242 "andl %"_msk",%"_LO32 _tmp"; " \
243 "orl %"_LO32 _tmp",%"_sav"; "
244
245 #ifdef CONFIG_X86_64
246 #define ON64(x) x
247 #else
248 #define ON64(x)
249 #endif
250
251 #define ____emulate_2op(ctxt, _op, _x, _y, _suffix, _dsttype) \
252 do { \
253 __asm__ __volatile__ ( \
254 _PRE_EFLAGS("0", "4", "2") \
255 _op _suffix " %"_x"3,%1; " \
256 _POST_EFLAGS("0", "4", "2") \
257 : "=m" ((ctxt)->eflags), \
258 "+q" (*(_dsttype*)&(ctxt)->dst.val), \
259 "=&r" (_tmp) \
260 : _y ((ctxt)->src.val), "i" (EFLAGS_MASK)); \
261 } while (0)
262
263
264 /* Raw emulation: instruction has two explicit operands. */
265 #define __emulate_2op_nobyte(ctxt,_op,_wx,_wy,_lx,_ly,_qx,_qy) \
266 do { \
267 unsigned long _tmp; \
268 \
269 switch ((ctxt)->dst.bytes) { \
270 case 2: \
271 ____emulate_2op(ctxt,_op,_wx,_wy,"w",u16); \
272 break; \
273 case 4: \
274 ____emulate_2op(ctxt,_op,_lx,_ly,"l",u32); \
275 break; \
276 case 8: \
277 ON64(____emulate_2op(ctxt,_op,_qx,_qy,"q",u64)); \
278 break; \
279 } \
280 } while (0)
281
282 #define __emulate_2op(ctxt,_op,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \
283 do { \
284 unsigned long _tmp; \
285 switch ((ctxt)->dst.bytes) { \
286 case 1: \
287 ____emulate_2op(ctxt,_op,_bx,_by,"b",u8); \
288 break; \
289 default: \
290 __emulate_2op_nobyte(ctxt, _op, \
291 _wx, _wy, _lx, _ly, _qx, _qy); \
292 break; \
293 } \
294 } while (0)
295
296 /* Source operand is byte-sized and may be restricted to just %cl. */
297 #define emulate_2op_SrcB(ctxt, _op) \
298 __emulate_2op(ctxt, _op, "b", "c", "b", "c", "b", "c", "b", "c")
299
300 /* Source operand is byte, word, long or quad sized. */
301 #define emulate_2op_SrcV(ctxt, _op) \
302 __emulate_2op(ctxt, _op, "b", "q", "w", "r", _LO32, "r", "", "r")
303
304 /* Source operand is word, long or quad sized. */
305 #define emulate_2op_SrcV_nobyte(ctxt, _op) \
306 __emulate_2op_nobyte(ctxt, _op, "w", "r", _LO32, "r", "", "r")
307
308 /* Instruction has three operands and one operand is stored in ECX register */
309 #define __emulate_2op_cl(ctxt, _op, _suffix, _type) \
310 do { \
311 unsigned long _tmp; \
312 _type _clv = (ctxt)->src2.val; \
313 _type _srcv = (ctxt)->src.val; \
314 _type _dstv = (ctxt)->dst.val; \
315 \
316 __asm__ __volatile__ ( \
317 _PRE_EFLAGS("0", "5", "2") \
318 _op _suffix " %4,%1 \n" \
319 _POST_EFLAGS("0", "5", "2") \
320 : "=m" ((ctxt)->eflags), "+r" (_dstv), "=&r" (_tmp) \
321 : "c" (_clv) , "r" (_srcv), "i" (EFLAGS_MASK) \
322 ); \
323 \
324 (ctxt)->src2.val = (unsigned long) _clv; \
325 (ctxt)->src2.val = (unsigned long) _srcv; \
326 (ctxt)->dst.val = (unsigned long) _dstv; \
327 } while (0)
328
329 #define emulate_2op_cl(ctxt, _op) \
330 do { \
331 switch ((ctxt)->dst.bytes) { \
332 case 2: \
333 __emulate_2op_cl(ctxt, _op, "w", u16); \
334 break; \
335 case 4: \
336 __emulate_2op_cl(ctxt, _op, "l", u32); \
337 break; \
338 case 8: \
339 ON64(__emulate_2op_cl(ctxt, _op, "q", ulong)); \
340 break; \
341 } \
342 } while (0)
343
344 #define __emulate_1op(ctxt, _op, _suffix) \
345 do { \
346 unsigned long _tmp; \
347 \
348 __asm__ __volatile__ ( \
349 _PRE_EFLAGS("0", "3", "2") \
350 _op _suffix " %1; " \
351 _POST_EFLAGS("0", "3", "2") \
352 : "=m" ((ctxt)->eflags), "+m" ((ctxt)->dst.val), \
353 "=&r" (_tmp) \
354 : "i" (EFLAGS_MASK)); \
355 } while (0)
356
357 /* Instruction has only one explicit operand (no source operand). */
358 #define emulate_1op(ctxt, _op) \
359 do { \
360 switch ((ctxt)->dst.bytes) { \
361 case 1: __emulate_1op(ctxt, _op, "b"); break; \
362 case 2: __emulate_1op(ctxt, _op, "w"); break; \
363 case 4: __emulate_1op(ctxt, _op, "l"); break; \
364 case 8: ON64(__emulate_1op(ctxt, _op, "q")); break; \
365 } \
366 } while (0)
367
368 #define __emulate_1op_rax_rdx(ctxt, _op, _suffix, _ex) \
369 do { \
370 unsigned long _tmp; \
371 ulong *rax = &(ctxt)->regs[VCPU_REGS_RAX]; \
372 ulong *rdx = &(ctxt)->regs[VCPU_REGS_RDX]; \
373 \
374 __asm__ __volatile__ ( \
375 _PRE_EFLAGS("0", "5", "1") \
376 "1: \n\t" \
377 _op _suffix " %6; " \
378 "2: \n\t" \
379 _POST_EFLAGS("0", "5", "1") \
380 ".pushsection .fixup,\"ax\" \n\t" \
381 "3: movb $1, %4 \n\t" \
382 "jmp 2b \n\t" \
383 ".popsection \n\t" \
384 _ASM_EXTABLE(1b, 3b) \
385 : "=m" ((ctxt)->eflags), "=&r" (_tmp), \
386 "+a" (*rax), "+d" (*rdx), "+qm"(_ex) \
387 : "i" (EFLAGS_MASK), "m" ((ctxt)->src.val), \
388 "a" (*rax), "d" (*rdx)); \
389 } while (0)
390
391 /* instruction has only one source operand, destination is implicit (e.g. mul, div, imul, idiv) */
392 #define emulate_1op_rax_rdx(ctxt, _op, _ex) \
393 do { \
394 switch((ctxt)->src.bytes) { \
395 case 1: \
396 __emulate_1op_rax_rdx(ctxt, _op, "b", _ex); \
397 break; \
398 case 2: \
399 __emulate_1op_rax_rdx(ctxt, _op, "w", _ex); \
400 break; \
401 case 4: \
402 __emulate_1op_rax_rdx(ctxt, _op, "l", _ex); \
403 break; \
404 case 8: ON64( \
405 __emulate_1op_rax_rdx(ctxt, _op, "q", _ex)); \
406 break; \
407 } \
408 } while (0)
409
410 static int emulator_check_intercept(struct x86_emulate_ctxt *ctxt,
411 enum x86_intercept intercept,
412 enum x86_intercept_stage stage)
413 {
414 struct x86_instruction_info info = {
415 .intercept = intercept,
416 .rep_prefix = ctxt->rep_prefix,
417 .modrm_mod = ctxt->modrm_mod,
418 .modrm_reg = ctxt->modrm_reg,
419 .modrm_rm = ctxt->modrm_rm,
420 .src_val = ctxt->src.val64,
421 .src_bytes = ctxt->src.bytes,
422 .dst_bytes = ctxt->dst.bytes,
423 .ad_bytes = ctxt->ad_bytes,
424 .next_rip = ctxt->eip,
425 };
426
427 return ctxt->ops->intercept(ctxt, &info, stage);
428 }
429
430 static inline unsigned long ad_mask(struct x86_emulate_ctxt *ctxt)
431 {
432 return (1UL << (ctxt->ad_bytes << 3)) - 1;
433 }
434
435 /* Access/update address held in a register, based on addressing mode. */
436 static inline unsigned long
437 address_mask(struct x86_emulate_ctxt *ctxt, unsigned long reg)
438 {
439 if (ctxt->ad_bytes == sizeof(unsigned long))
440 return reg;
441 else
442 return reg & ad_mask(ctxt);
443 }
444
445 static inline unsigned long
446 register_address(struct x86_emulate_ctxt *ctxt, unsigned long reg)
447 {
448 return address_mask(ctxt, reg);
449 }
450
451 static inline void
452 register_address_increment(struct x86_emulate_ctxt *ctxt, unsigned long *reg, int inc)
453 {
454 if (ctxt->ad_bytes == sizeof(unsigned long))
455 *reg += inc;
456 else
457 *reg = (*reg & ~ad_mask(ctxt)) | ((*reg + inc) & ad_mask(ctxt));
458 }
459
460 static inline void jmp_rel(struct x86_emulate_ctxt *ctxt, int rel)
461 {
462 register_address_increment(ctxt, &ctxt->_eip, rel);
463 }
464
465 static u32 desc_limit_scaled(struct desc_struct *desc)
466 {
467 u32 limit = get_desc_limit(desc);
468
469 return desc->g ? (limit << 12) | 0xfff : limit;
470 }
471
472 static void set_seg_override(struct x86_emulate_ctxt *ctxt, int seg)
473 {
474 ctxt->has_seg_override = true;
475 ctxt->seg_override = seg;
476 }
477
478 static unsigned long seg_base(struct x86_emulate_ctxt *ctxt, int seg)
479 {
480 if (ctxt->mode == X86EMUL_MODE_PROT64 && seg < VCPU_SREG_FS)
481 return 0;
482
483 return ctxt->ops->get_cached_segment_base(ctxt, seg);
484 }
485
486 static unsigned seg_override(struct x86_emulate_ctxt *ctxt)
487 {
488 if (!ctxt->has_seg_override)
489 return 0;
490
491 return ctxt->seg_override;
492 }
493
494 static int emulate_exception(struct x86_emulate_ctxt *ctxt, int vec,
495 u32 error, bool valid)
496 {
497 ctxt->exception.vector = vec;
498 ctxt->exception.error_code = error;
499 ctxt->exception.error_code_valid = valid;
500 return X86EMUL_PROPAGATE_FAULT;
501 }
502
503 static int emulate_db(struct x86_emulate_ctxt *ctxt)
504 {
505 return emulate_exception(ctxt, DB_VECTOR, 0, false);
506 }
507
508 static int emulate_gp(struct x86_emulate_ctxt *ctxt, int err)
509 {
510 return emulate_exception(ctxt, GP_VECTOR, err, true);
511 }
512
513 static int emulate_ss(struct x86_emulate_ctxt *ctxt, int err)
514 {
515 return emulate_exception(ctxt, SS_VECTOR, err, true);
516 }
517
518 static int emulate_ud(struct x86_emulate_ctxt *ctxt)
519 {
520 return emulate_exception(ctxt, UD_VECTOR, 0, false);
521 }
522
523 static int emulate_ts(struct x86_emulate_ctxt *ctxt, int err)
524 {
525 return emulate_exception(ctxt, TS_VECTOR, err, true);
526 }
527
528 static int emulate_de(struct x86_emulate_ctxt *ctxt)
529 {
530 return emulate_exception(ctxt, DE_VECTOR, 0, false);
531 }
532
533 static int emulate_nm(struct x86_emulate_ctxt *ctxt)
534 {
535 return emulate_exception(ctxt, NM_VECTOR, 0, false);
536 }
537
538 static u16 get_segment_selector(struct x86_emulate_ctxt *ctxt, unsigned seg)
539 {
540 u16 selector;
541 struct desc_struct desc;
542
543 ctxt->ops->get_segment(ctxt, &selector, &desc, NULL, seg);
544 return selector;
545 }
546
547 static void set_segment_selector(struct x86_emulate_ctxt *ctxt, u16 selector,
548 unsigned seg)
549 {
550 u16 dummy;
551 u32 base3;
552 struct desc_struct desc;
553
554 ctxt->ops->get_segment(ctxt, &dummy, &desc, &base3, seg);
555 ctxt->ops->set_segment(ctxt, selector, &desc, base3, seg);
556 }
557
558 static int __linearize(struct x86_emulate_ctxt *ctxt,
559 struct segmented_address addr,
560 unsigned size, bool write, bool fetch,
561 ulong *linear)
562 {
563 struct desc_struct desc;
564 bool usable;
565 ulong la;
566 u32 lim;
567 u16 sel;
568 unsigned cpl, rpl;
569
570 la = seg_base(ctxt, addr.seg) + addr.ea;
571 switch (ctxt->mode) {
572 case X86EMUL_MODE_REAL:
573 break;
574 case X86EMUL_MODE_PROT64:
575 if (((signed long)la << 16) >> 16 != la)
576 return emulate_gp(ctxt, 0);
577 break;
578 default:
579 usable = ctxt->ops->get_segment(ctxt, &sel, &desc, NULL,
580 addr.seg);
581 if (!usable)
582 goto bad;
583 /* code segment or read-only data segment */
584 if (((desc.type & 8) || !(desc.type & 2)) && write)
585 goto bad;
586 /* unreadable code segment */
587 if (!fetch && (desc.type & 8) && !(desc.type & 2))
588 goto bad;
589 lim = desc_limit_scaled(&desc);
590 if ((desc.type & 8) || !(desc.type & 4)) {
591 /* expand-up segment */
592 if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim)
593 goto bad;
594 } else {
595 /* exapand-down segment */
596 if (addr.ea <= lim || (u32)(addr.ea + size - 1) <= lim)
597 goto bad;
598 lim = desc.d ? 0xffffffff : 0xffff;
599 if (addr.ea > lim || (u32)(addr.ea + size - 1) > lim)
600 goto bad;
601 }
602 cpl = ctxt->ops->cpl(ctxt);
603 rpl = sel & 3;
604 cpl = max(cpl, rpl);
605 if (!(desc.type & 8)) {
606 /* data segment */
607 if (cpl > desc.dpl)
608 goto bad;
609 } else if ((desc.type & 8) && !(desc.type & 4)) {
610 /* nonconforming code segment */
611 if (cpl != desc.dpl)
612 goto bad;
613 } else if ((desc.type & 8) && (desc.type & 4)) {
614 /* conforming code segment */
615 if (cpl < desc.dpl)
616 goto bad;
617 }
618 break;
619 }
620 if (fetch ? ctxt->mode != X86EMUL_MODE_PROT64 : ctxt->ad_bytes != 8)
621 la &= (u32)-1;
622 *linear = la;
623 return X86EMUL_CONTINUE;
624 bad:
625 if (addr.seg == VCPU_SREG_SS)
626 return emulate_ss(ctxt, addr.seg);
627 else
628 return emulate_gp(ctxt, addr.seg);
629 }
630
631 static int linearize(struct x86_emulate_ctxt *ctxt,
632 struct segmented_address addr,
633 unsigned size, bool write,
634 ulong *linear)
635 {
636 return __linearize(ctxt, addr, size, write, false, linear);
637 }
638
639
640 static int segmented_read_std(struct x86_emulate_ctxt *ctxt,
641 struct segmented_address addr,
642 void *data,
643 unsigned size)
644 {
645 int rc;
646 ulong linear;
647
648 rc = linearize(ctxt, addr, size, false, &linear);
649 if (rc != X86EMUL_CONTINUE)
650 return rc;
651 return ctxt->ops->read_std(ctxt, linear, data, size, &ctxt->exception);
652 }
653
654 /*
655 * Fetch the next byte of the instruction being emulated which is pointed to
656 * by ctxt->_eip, then increment ctxt->_eip.
657 *
658 * Also prefetch the remaining bytes of the instruction without crossing page
659 * boundary if they are not in fetch_cache yet.
660 */
661 static int do_insn_fetch_byte(struct x86_emulate_ctxt *ctxt, u8 *dest)
662 {
663 struct fetch_cache *fc = &ctxt->fetch;
664 int rc;
665 int size, cur_size;
666
667 if (ctxt->_eip == fc->end) {
668 unsigned long linear;
669 struct segmented_address addr = { .seg = VCPU_SREG_CS,
670 .ea = ctxt->_eip };
671 cur_size = fc->end - fc->start;
672 size = min(15UL - cur_size,
673 PAGE_SIZE - offset_in_page(ctxt->_eip));
674 rc = __linearize(ctxt, addr, size, false, true, &linear);
675 if (unlikely(rc != X86EMUL_CONTINUE))
676 return rc;
677 rc = ctxt->ops->fetch(ctxt, linear, fc->data + cur_size,
678 size, &ctxt->exception);
679 if (unlikely(rc != X86EMUL_CONTINUE))
680 return rc;
681 fc->end += size;
682 }
683 *dest = fc->data[ctxt->_eip - fc->start];
684 ctxt->_eip++;
685 return X86EMUL_CONTINUE;
686 }
687
688 static int do_insn_fetch(struct x86_emulate_ctxt *ctxt,
689 void *dest, unsigned size)
690 {
691 int rc;
692
693 /* x86 instructions are limited to 15 bytes. */
694 if (unlikely(ctxt->_eip + size - ctxt->eip > 15))
695 return X86EMUL_UNHANDLEABLE;
696 while (size--) {
697 rc = do_insn_fetch_byte(ctxt, dest++);
698 if (rc != X86EMUL_CONTINUE)
699 return rc;
700 }
701 return X86EMUL_CONTINUE;
702 }
703
704 /* Fetch next part of the instruction being emulated. */
705 #define insn_fetch(_type, _ctxt) \
706 ({ unsigned long _x; \
707 rc = do_insn_fetch(_ctxt, &_x, sizeof(_type)); \
708 if (rc != X86EMUL_CONTINUE) \
709 goto done; \
710 (_type)_x; \
711 })
712
713 #define insn_fetch_arr(_arr, _size, _ctxt) \
714 ({ rc = do_insn_fetch(_ctxt, _arr, (_size)); \
715 if (rc != X86EMUL_CONTINUE) \
716 goto done; \
717 })
718
719 /*
720 * Given the 'reg' portion of a ModRM byte, and a register block, return a
721 * pointer into the block that addresses the relevant register.
722 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
723 */
724 static void *decode_register(u8 modrm_reg, unsigned long *regs,
725 int highbyte_regs)
726 {
727 void *p;
728
729 p = &regs[modrm_reg];
730 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
731 p = (unsigned char *)&regs[modrm_reg & 3] + 1;
732 return p;
733 }
734
735 static int read_descriptor(struct x86_emulate_ctxt *ctxt,
736 struct segmented_address addr,
737 u16 *size, unsigned long *address, int op_bytes)
738 {
739 int rc;
740
741 if (op_bytes == 2)
742 op_bytes = 3;
743 *address = 0;
744 rc = segmented_read_std(ctxt, addr, size, 2);
745 if (rc != X86EMUL_CONTINUE)
746 return rc;
747 addr.ea += 2;
748 rc = segmented_read_std(ctxt, addr, address, op_bytes);
749 return rc;
750 }
751
752 static int test_cc(unsigned int condition, unsigned int flags)
753 {
754 int rc = 0;
755
756 switch ((condition & 15) >> 1) {
757 case 0: /* o */
758 rc |= (flags & EFLG_OF);
759 break;
760 case 1: /* b/c/nae */
761 rc |= (flags & EFLG_CF);
762 break;
763 case 2: /* z/e */
764 rc |= (flags & EFLG_ZF);
765 break;
766 case 3: /* be/na */
767 rc |= (flags & (EFLG_CF|EFLG_ZF));
768 break;
769 case 4: /* s */
770 rc |= (flags & EFLG_SF);
771 break;
772 case 5: /* p/pe */
773 rc |= (flags & EFLG_PF);
774 break;
775 case 7: /* le/ng */
776 rc |= (flags & EFLG_ZF);
777 /* fall through */
778 case 6: /* l/nge */
779 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
780 break;
781 }
782
783 /* Odd condition identifiers (lsb == 1) have inverted sense. */
784 return (!!rc ^ (condition & 1));
785 }
786
787 static void fetch_register_operand(struct operand *op)
788 {
789 switch (op->bytes) {
790 case 1:
791 op->val = *(u8 *)op->addr.reg;
792 break;
793 case 2:
794 op->val = *(u16 *)op->addr.reg;
795 break;
796 case 4:
797 op->val = *(u32 *)op->addr.reg;
798 break;
799 case 8:
800 op->val = *(u64 *)op->addr.reg;
801 break;
802 }
803 }
804
805 static void read_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data, int reg)
806 {
807 ctxt->ops->get_fpu(ctxt);
808 switch (reg) {
809 case 0: asm("movdqu %%xmm0, %0" : "=m"(*data)); break;
810 case 1: asm("movdqu %%xmm1, %0" : "=m"(*data)); break;
811 case 2: asm("movdqu %%xmm2, %0" : "=m"(*data)); break;
812 case 3: asm("movdqu %%xmm3, %0" : "=m"(*data)); break;
813 case 4: asm("movdqu %%xmm4, %0" : "=m"(*data)); break;
814 case 5: asm("movdqu %%xmm5, %0" : "=m"(*data)); break;
815 case 6: asm("movdqu %%xmm6, %0" : "=m"(*data)); break;
816 case 7: asm("movdqu %%xmm7, %0" : "=m"(*data)); break;
817 #ifdef CONFIG_X86_64
818 case 8: asm("movdqu %%xmm8, %0" : "=m"(*data)); break;
819 case 9: asm("movdqu %%xmm9, %0" : "=m"(*data)); break;
820 case 10: asm("movdqu %%xmm10, %0" : "=m"(*data)); break;
821 case 11: asm("movdqu %%xmm11, %0" : "=m"(*data)); break;
822 case 12: asm("movdqu %%xmm12, %0" : "=m"(*data)); break;
823 case 13: asm("movdqu %%xmm13, %0" : "=m"(*data)); break;
824 case 14: asm("movdqu %%xmm14, %0" : "=m"(*data)); break;
825 case 15: asm("movdqu %%xmm15, %0" : "=m"(*data)); break;
826 #endif
827 default: BUG();
828 }
829 ctxt->ops->put_fpu(ctxt);
830 }
831
832 static void write_sse_reg(struct x86_emulate_ctxt *ctxt, sse128_t *data,
833 int reg)
834 {
835 ctxt->ops->get_fpu(ctxt);
836 switch (reg) {
837 case 0: asm("movdqu %0, %%xmm0" : : "m"(*data)); break;
838 case 1: asm("movdqu %0, %%xmm1" : : "m"(*data)); break;
839 case 2: asm("movdqu %0, %%xmm2" : : "m"(*data)); break;
840 case 3: asm("movdqu %0, %%xmm3" : : "m"(*data)); break;
841 case 4: asm("movdqu %0, %%xmm4" : : "m"(*data)); break;
842 case 5: asm("movdqu %0, %%xmm5" : : "m"(*data)); break;
843 case 6: asm("movdqu %0, %%xmm6" : : "m"(*data)); break;
844 case 7: asm("movdqu %0, %%xmm7" : : "m"(*data)); break;
845 #ifdef CONFIG_X86_64
846 case 8: asm("movdqu %0, %%xmm8" : : "m"(*data)); break;
847 case 9: asm("movdqu %0, %%xmm9" : : "m"(*data)); break;
848 case 10: asm("movdqu %0, %%xmm10" : : "m"(*data)); break;
849 case 11: asm("movdqu %0, %%xmm11" : : "m"(*data)); break;
850 case 12: asm("movdqu %0, %%xmm12" : : "m"(*data)); break;
851 case 13: asm("movdqu %0, %%xmm13" : : "m"(*data)); break;
852 case 14: asm("movdqu %0, %%xmm14" : : "m"(*data)); break;
853 case 15: asm("movdqu %0, %%xmm15" : : "m"(*data)); break;
854 #endif
855 default: BUG();
856 }
857 ctxt->ops->put_fpu(ctxt);
858 }
859
860 static void decode_register_operand(struct x86_emulate_ctxt *ctxt,
861 struct operand *op,
862 int inhibit_bytereg)
863 {
864 unsigned reg = ctxt->modrm_reg;
865 int highbyte_regs = ctxt->rex_prefix == 0;
866
867 if (!(ctxt->d & ModRM))
868 reg = (ctxt->b & 7) | ((ctxt->rex_prefix & 1) << 3);
869
870 if (ctxt->d & Sse) {
871 op->type = OP_XMM;
872 op->bytes = 16;
873 op->addr.xmm = reg;
874 read_sse_reg(ctxt, &op->vec_val, reg);
875 return;
876 }
877
878 op->type = OP_REG;
879 if ((ctxt->d & ByteOp) && !inhibit_bytereg) {
880 op->addr.reg = decode_register(reg, ctxt->regs, highbyte_regs);
881 op->bytes = 1;
882 } else {
883 op->addr.reg = decode_register(reg, ctxt->regs, 0);
884 op->bytes = ctxt->op_bytes;
885 }
886 fetch_register_operand(op);
887 op->orig_val = op->val;
888 }
889
890 static int decode_modrm(struct x86_emulate_ctxt *ctxt,
891 struct operand *op)
892 {
893 u8 sib;
894 int index_reg = 0, base_reg = 0, scale;
895 int rc = X86EMUL_CONTINUE;
896 ulong modrm_ea = 0;
897
898 if (ctxt->rex_prefix) {
899 ctxt->modrm_reg = (ctxt->rex_prefix & 4) << 1; /* REX.R */
900 index_reg = (ctxt->rex_prefix & 2) << 2; /* REX.X */
901 ctxt->modrm_rm = base_reg = (ctxt->rex_prefix & 1) << 3; /* REG.B */
902 }
903
904 ctxt->modrm = insn_fetch(u8, ctxt);
905 ctxt->modrm_mod |= (ctxt->modrm & 0xc0) >> 6;
906 ctxt->modrm_reg |= (ctxt->modrm & 0x38) >> 3;
907 ctxt->modrm_rm |= (ctxt->modrm & 0x07);
908 ctxt->modrm_seg = VCPU_SREG_DS;
909
910 if (ctxt->modrm_mod == 3) {
911 op->type = OP_REG;
912 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
913 op->addr.reg = decode_register(ctxt->modrm_rm,
914 ctxt->regs, ctxt->d & ByteOp);
915 if (ctxt->d & Sse) {
916 op->type = OP_XMM;
917 op->bytes = 16;
918 op->addr.xmm = ctxt->modrm_rm;
919 read_sse_reg(ctxt, &op->vec_val, ctxt->modrm_rm);
920 return rc;
921 }
922 fetch_register_operand(op);
923 return rc;
924 }
925
926 op->type = OP_MEM;
927
928 if (ctxt->ad_bytes == 2) {
929 unsigned bx = ctxt->regs[VCPU_REGS_RBX];
930 unsigned bp = ctxt->regs[VCPU_REGS_RBP];
931 unsigned si = ctxt->regs[VCPU_REGS_RSI];
932 unsigned di = ctxt->regs[VCPU_REGS_RDI];
933
934 /* 16-bit ModR/M decode. */
935 switch (ctxt->modrm_mod) {
936 case 0:
937 if (ctxt->modrm_rm == 6)
938 modrm_ea += insn_fetch(u16, ctxt);
939 break;
940 case 1:
941 modrm_ea += insn_fetch(s8, ctxt);
942 break;
943 case 2:
944 modrm_ea += insn_fetch(u16, ctxt);
945 break;
946 }
947 switch (ctxt->modrm_rm) {
948 case 0:
949 modrm_ea += bx + si;
950 break;
951 case 1:
952 modrm_ea += bx + di;
953 break;
954 case 2:
955 modrm_ea += bp + si;
956 break;
957 case 3:
958 modrm_ea += bp + di;
959 break;
960 case 4:
961 modrm_ea += si;
962 break;
963 case 5:
964 modrm_ea += di;
965 break;
966 case 6:
967 if (ctxt->modrm_mod != 0)
968 modrm_ea += bp;
969 break;
970 case 7:
971 modrm_ea += bx;
972 break;
973 }
974 if (ctxt->modrm_rm == 2 || ctxt->modrm_rm == 3 ||
975 (ctxt->modrm_rm == 6 && ctxt->modrm_mod != 0))
976 ctxt->modrm_seg = VCPU_SREG_SS;
977 modrm_ea = (u16)modrm_ea;
978 } else {
979 /* 32/64-bit ModR/M decode. */
980 if ((ctxt->modrm_rm & 7) == 4) {
981 sib = insn_fetch(u8, ctxt);
982 index_reg |= (sib >> 3) & 7;
983 base_reg |= sib & 7;
984 scale = sib >> 6;
985
986 if ((base_reg & 7) == 5 && ctxt->modrm_mod == 0)
987 modrm_ea += insn_fetch(s32, ctxt);
988 else
989 modrm_ea += ctxt->regs[base_reg];
990 if (index_reg != 4)
991 modrm_ea += ctxt->regs[index_reg] << scale;
992 } else if ((ctxt->modrm_rm & 7) == 5 && ctxt->modrm_mod == 0) {
993 if (ctxt->mode == X86EMUL_MODE_PROT64)
994 ctxt->rip_relative = 1;
995 } else
996 modrm_ea += ctxt->regs[ctxt->modrm_rm];
997 switch (ctxt->modrm_mod) {
998 case 0:
999 if (ctxt->modrm_rm == 5)
1000 modrm_ea += insn_fetch(s32, ctxt);
1001 break;
1002 case 1:
1003 modrm_ea += insn_fetch(s8, ctxt);
1004 break;
1005 case 2:
1006 modrm_ea += insn_fetch(s32, ctxt);
1007 break;
1008 }
1009 }
1010 op->addr.mem.ea = modrm_ea;
1011 done:
1012 return rc;
1013 }
1014
1015 static int decode_abs(struct x86_emulate_ctxt *ctxt,
1016 struct operand *op)
1017 {
1018 int rc = X86EMUL_CONTINUE;
1019
1020 op->type = OP_MEM;
1021 switch (ctxt->ad_bytes) {
1022 case 2:
1023 op->addr.mem.ea = insn_fetch(u16, ctxt);
1024 break;
1025 case 4:
1026 op->addr.mem.ea = insn_fetch(u32, ctxt);
1027 break;
1028 case 8:
1029 op->addr.mem.ea = insn_fetch(u64, ctxt);
1030 break;
1031 }
1032 done:
1033 return rc;
1034 }
1035
1036 static void fetch_bit_operand(struct x86_emulate_ctxt *ctxt)
1037 {
1038 long sv = 0, mask;
1039
1040 if (ctxt->dst.type == OP_MEM && ctxt->src.type == OP_REG) {
1041 mask = ~(ctxt->dst.bytes * 8 - 1);
1042
1043 if (ctxt->src.bytes == 2)
1044 sv = (s16)ctxt->src.val & (s16)mask;
1045 else if (ctxt->src.bytes == 4)
1046 sv = (s32)ctxt->src.val & (s32)mask;
1047
1048 ctxt->dst.addr.mem.ea += (sv >> 3);
1049 }
1050
1051 /* only subword offset */
1052 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
1053 }
1054
1055 static int read_emulated(struct x86_emulate_ctxt *ctxt,
1056 unsigned long addr, void *dest, unsigned size)
1057 {
1058 int rc;
1059 struct read_cache *mc = &ctxt->mem_read;
1060
1061 while (size) {
1062 int n = min(size, 8u);
1063 size -= n;
1064 if (mc->pos < mc->end)
1065 goto read_cached;
1066
1067 rc = ctxt->ops->read_emulated(ctxt, addr, mc->data + mc->end, n,
1068 &ctxt->exception);
1069 if (rc != X86EMUL_CONTINUE)
1070 return rc;
1071 mc->end += n;
1072
1073 read_cached:
1074 memcpy(dest, mc->data + mc->pos, n);
1075 mc->pos += n;
1076 dest += n;
1077 addr += n;
1078 }
1079 return X86EMUL_CONTINUE;
1080 }
1081
1082 static int segmented_read(struct x86_emulate_ctxt *ctxt,
1083 struct segmented_address addr,
1084 void *data,
1085 unsigned size)
1086 {
1087 int rc;
1088 ulong linear;
1089
1090 rc = linearize(ctxt, addr, size, false, &linear);
1091 if (rc != X86EMUL_CONTINUE)
1092 return rc;
1093 return read_emulated(ctxt, linear, data, size);
1094 }
1095
1096 static int segmented_write(struct x86_emulate_ctxt *ctxt,
1097 struct segmented_address addr,
1098 const void *data,
1099 unsigned size)
1100 {
1101 int rc;
1102 ulong linear;
1103
1104 rc = linearize(ctxt, addr, size, true, &linear);
1105 if (rc != X86EMUL_CONTINUE)
1106 return rc;
1107 return ctxt->ops->write_emulated(ctxt, linear, data, size,
1108 &ctxt->exception);
1109 }
1110
1111 static int segmented_cmpxchg(struct x86_emulate_ctxt *ctxt,
1112 struct segmented_address addr,
1113 const void *orig_data, const void *data,
1114 unsigned size)
1115 {
1116 int rc;
1117 ulong linear;
1118
1119 rc = linearize(ctxt, addr, size, true, &linear);
1120 if (rc != X86EMUL_CONTINUE)
1121 return rc;
1122 return ctxt->ops->cmpxchg_emulated(ctxt, linear, orig_data, data,
1123 size, &ctxt->exception);
1124 }
1125
1126 static int pio_in_emulated(struct x86_emulate_ctxt *ctxt,
1127 unsigned int size, unsigned short port,
1128 void *dest)
1129 {
1130 struct read_cache *rc = &ctxt->io_read;
1131
1132 if (rc->pos == rc->end) { /* refill pio read ahead */
1133 unsigned int in_page, n;
1134 unsigned int count = ctxt->rep_prefix ?
1135 address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) : 1;
1136 in_page = (ctxt->eflags & EFLG_DF) ?
1137 offset_in_page(ctxt->regs[VCPU_REGS_RDI]) :
1138 PAGE_SIZE - offset_in_page(ctxt->regs[VCPU_REGS_RDI]);
1139 n = min(min(in_page, (unsigned int)sizeof(rc->data)) / size,
1140 count);
1141 if (n == 0)
1142 n = 1;
1143 rc->pos = rc->end = 0;
1144 if (!ctxt->ops->pio_in_emulated(ctxt, size, port, rc->data, n))
1145 return 0;
1146 rc->end = n * size;
1147 }
1148
1149 memcpy(dest, rc->data + rc->pos, size);
1150 rc->pos += size;
1151 return 1;
1152 }
1153
1154 static void get_descriptor_table_ptr(struct x86_emulate_ctxt *ctxt,
1155 u16 selector, struct desc_ptr *dt)
1156 {
1157 struct x86_emulate_ops *ops = ctxt->ops;
1158
1159 if (selector & 1 << 2) {
1160 struct desc_struct desc;
1161 u16 sel;
1162
1163 memset (dt, 0, sizeof *dt);
1164 if (!ops->get_segment(ctxt, &sel, &desc, NULL, VCPU_SREG_LDTR))
1165 return;
1166
1167 dt->size = desc_limit_scaled(&desc); /* what if limit > 65535? */
1168 dt->address = get_desc_base(&desc);
1169 } else
1170 ops->get_gdt(ctxt, dt);
1171 }
1172
1173 /* allowed just for 8 bytes segments */
1174 static int read_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1175 u16 selector, struct desc_struct *desc)
1176 {
1177 struct desc_ptr dt;
1178 u16 index = selector >> 3;
1179 ulong addr;
1180
1181 get_descriptor_table_ptr(ctxt, selector, &dt);
1182
1183 if (dt.size < index * 8 + 7)
1184 return emulate_gp(ctxt, selector & 0xfffc);
1185
1186 addr = dt.address + index * 8;
1187 return ctxt->ops->read_std(ctxt, addr, desc, sizeof *desc,
1188 &ctxt->exception);
1189 }
1190
1191 /* allowed just for 8 bytes segments */
1192 static int write_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1193 u16 selector, struct desc_struct *desc)
1194 {
1195 struct desc_ptr dt;
1196 u16 index = selector >> 3;
1197 ulong addr;
1198
1199 get_descriptor_table_ptr(ctxt, selector, &dt);
1200
1201 if (dt.size < index * 8 + 7)
1202 return emulate_gp(ctxt, selector & 0xfffc);
1203
1204 addr = dt.address + index * 8;
1205 return ctxt->ops->write_std(ctxt, addr, desc, sizeof *desc,
1206 &ctxt->exception);
1207 }
1208
1209 /* Does not support long mode */
1210 static int load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
1211 u16 selector, int seg)
1212 {
1213 struct desc_struct seg_desc;
1214 u8 dpl, rpl, cpl;
1215 unsigned err_vec = GP_VECTOR;
1216 u32 err_code = 0;
1217 bool null_selector = !(selector & ~0x3); /* 0000-0003 are null */
1218 int ret;
1219
1220 memset(&seg_desc, 0, sizeof seg_desc);
1221
1222 if ((seg <= VCPU_SREG_GS && ctxt->mode == X86EMUL_MODE_VM86)
1223 || ctxt->mode == X86EMUL_MODE_REAL) {
1224 /* set real mode segment descriptor */
1225 set_desc_base(&seg_desc, selector << 4);
1226 set_desc_limit(&seg_desc, 0xffff);
1227 seg_desc.type = 3;
1228 seg_desc.p = 1;
1229 seg_desc.s = 1;
1230 goto load;
1231 }
1232
1233 /* NULL selector is not valid for TR, CS and SS */
1234 if ((seg == VCPU_SREG_CS || seg == VCPU_SREG_SS || seg == VCPU_SREG_TR)
1235 && null_selector)
1236 goto exception;
1237
1238 /* TR should be in GDT only */
1239 if (seg == VCPU_SREG_TR && (selector & (1 << 2)))
1240 goto exception;
1241
1242 if (null_selector) /* for NULL selector skip all following checks */
1243 goto load;
1244
1245 ret = read_segment_descriptor(ctxt, selector, &seg_desc);
1246 if (ret != X86EMUL_CONTINUE)
1247 return ret;
1248
1249 err_code = selector & 0xfffc;
1250 err_vec = GP_VECTOR;
1251
1252 /* can't load system descriptor into segment selecor */
1253 if (seg <= VCPU_SREG_GS && !seg_desc.s)
1254 goto exception;
1255
1256 if (!seg_desc.p) {
1257 err_vec = (seg == VCPU_SREG_SS) ? SS_VECTOR : NP_VECTOR;
1258 goto exception;
1259 }
1260
1261 rpl = selector & 3;
1262 dpl = seg_desc.dpl;
1263 cpl = ctxt->ops->cpl(ctxt);
1264
1265 switch (seg) {
1266 case VCPU_SREG_SS:
1267 /*
1268 * segment is not a writable data segment or segment
1269 * selector's RPL != CPL or segment selector's RPL != CPL
1270 */
1271 if (rpl != cpl || (seg_desc.type & 0xa) != 0x2 || dpl != cpl)
1272 goto exception;
1273 break;
1274 case VCPU_SREG_CS:
1275 if (!(seg_desc.type & 8))
1276 goto exception;
1277
1278 if (seg_desc.type & 4) {
1279 /* conforming */
1280 if (dpl > cpl)
1281 goto exception;
1282 } else {
1283 /* nonconforming */
1284 if (rpl > cpl || dpl != cpl)
1285 goto exception;
1286 }
1287 /* CS(RPL) <- CPL */
1288 selector = (selector & 0xfffc) | cpl;
1289 break;
1290 case VCPU_SREG_TR:
1291 if (seg_desc.s || (seg_desc.type != 1 && seg_desc.type != 9))
1292 goto exception;
1293 break;
1294 case VCPU_SREG_LDTR:
1295 if (seg_desc.s || seg_desc.type != 2)
1296 goto exception;
1297 break;
1298 default: /* DS, ES, FS, or GS */
1299 /*
1300 * segment is not a data or readable code segment or
1301 * ((segment is a data or nonconforming code segment)
1302 * and (both RPL and CPL > DPL))
1303 */
1304 if ((seg_desc.type & 0xa) == 0x8 ||
1305 (((seg_desc.type & 0xc) != 0xc) &&
1306 (rpl > dpl && cpl > dpl)))
1307 goto exception;
1308 break;
1309 }
1310
1311 if (seg_desc.s) {
1312 /* mark segment as accessed */
1313 seg_desc.type |= 1;
1314 ret = write_segment_descriptor(ctxt, selector, &seg_desc);
1315 if (ret != X86EMUL_CONTINUE)
1316 return ret;
1317 }
1318 load:
1319 ctxt->ops->set_segment(ctxt, selector, &seg_desc, 0, seg);
1320 return X86EMUL_CONTINUE;
1321 exception:
1322 emulate_exception(ctxt, err_vec, err_code, true);
1323 return X86EMUL_PROPAGATE_FAULT;
1324 }
1325
1326 static void write_register_operand(struct operand *op)
1327 {
1328 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
1329 switch (op->bytes) {
1330 case 1:
1331 *(u8 *)op->addr.reg = (u8)op->val;
1332 break;
1333 case 2:
1334 *(u16 *)op->addr.reg = (u16)op->val;
1335 break;
1336 case 4:
1337 *op->addr.reg = (u32)op->val;
1338 break; /* 64b: zero-extend */
1339 case 8:
1340 *op->addr.reg = op->val;
1341 break;
1342 }
1343 }
1344
1345 static int writeback(struct x86_emulate_ctxt *ctxt)
1346 {
1347 int rc;
1348
1349 switch (ctxt->dst.type) {
1350 case OP_REG:
1351 write_register_operand(&ctxt->dst);
1352 break;
1353 case OP_MEM:
1354 if (ctxt->lock_prefix)
1355 rc = segmented_cmpxchg(ctxt,
1356 ctxt->dst.addr.mem,
1357 &ctxt->dst.orig_val,
1358 &ctxt->dst.val,
1359 ctxt->dst.bytes);
1360 else
1361 rc = segmented_write(ctxt,
1362 ctxt->dst.addr.mem,
1363 &ctxt->dst.val,
1364 ctxt->dst.bytes);
1365 if (rc != X86EMUL_CONTINUE)
1366 return rc;
1367 break;
1368 case OP_XMM:
1369 write_sse_reg(ctxt, &ctxt->dst.vec_val, ctxt->dst.addr.xmm);
1370 break;
1371 case OP_NONE:
1372 /* no writeback */
1373 break;
1374 default:
1375 break;
1376 }
1377 return X86EMUL_CONTINUE;
1378 }
1379
1380 static int em_push(struct x86_emulate_ctxt *ctxt)
1381 {
1382 struct segmented_address addr;
1383
1384 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], -ctxt->op_bytes);
1385 addr.ea = register_address(ctxt, ctxt->regs[VCPU_REGS_RSP]);
1386 addr.seg = VCPU_SREG_SS;
1387
1388 /* Disable writeback. */
1389 ctxt->dst.type = OP_NONE;
1390 return segmented_write(ctxt, addr, &ctxt->src.val, ctxt->op_bytes);
1391 }
1392
1393 static int emulate_pop(struct x86_emulate_ctxt *ctxt,
1394 void *dest, int len)
1395 {
1396 int rc;
1397 struct segmented_address addr;
1398
1399 addr.ea = register_address(ctxt, ctxt->regs[VCPU_REGS_RSP]);
1400 addr.seg = VCPU_SREG_SS;
1401 rc = segmented_read(ctxt, addr, dest, len);
1402 if (rc != X86EMUL_CONTINUE)
1403 return rc;
1404
1405 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], len);
1406 return rc;
1407 }
1408
1409 static int em_pop(struct x86_emulate_ctxt *ctxt)
1410 {
1411 return emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1412 }
1413
1414 static int emulate_popf(struct x86_emulate_ctxt *ctxt,
1415 void *dest, int len)
1416 {
1417 int rc;
1418 unsigned long val, change_mask;
1419 int iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
1420 int cpl = ctxt->ops->cpl(ctxt);
1421
1422 rc = emulate_pop(ctxt, &val, len);
1423 if (rc != X86EMUL_CONTINUE)
1424 return rc;
1425
1426 change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
1427 | EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID;
1428
1429 switch(ctxt->mode) {
1430 case X86EMUL_MODE_PROT64:
1431 case X86EMUL_MODE_PROT32:
1432 case X86EMUL_MODE_PROT16:
1433 if (cpl == 0)
1434 change_mask |= EFLG_IOPL;
1435 if (cpl <= iopl)
1436 change_mask |= EFLG_IF;
1437 break;
1438 case X86EMUL_MODE_VM86:
1439 if (iopl < 3)
1440 return emulate_gp(ctxt, 0);
1441 change_mask |= EFLG_IF;
1442 break;
1443 default: /* real mode */
1444 change_mask |= (EFLG_IOPL | EFLG_IF);
1445 break;
1446 }
1447
1448 *(unsigned long *)dest =
1449 (ctxt->eflags & ~change_mask) | (val & change_mask);
1450
1451 return rc;
1452 }
1453
1454 static int em_popf(struct x86_emulate_ctxt *ctxt)
1455 {
1456 ctxt->dst.type = OP_REG;
1457 ctxt->dst.addr.reg = &ctxt->eflags;
1458 ctxt->dst.bytes = ctxt->op_bytes;
1459 return emulate_popf(ctxt, &ctxt->dst.val, ctxt->op_bytes);
1460 }
1461
1462 static int em_push_sreg(struct x86_emulate_ctxt *ctxt)
1463 {
1464 int seg = ctxt->src2.val;
1465
1466 ctxt->src.val = get_segment_selector(ctxt, seg);
1467
1468 return em_push(ctxt);
1469 }
1470
1471 static int em_pop_sreg(struct x86_emulate_ctxt *ctxt)
1472 {
1473 int seg = ctxt->src2.val;
1474 unsigned long selector;
1475 int rc;
1476
1477 rc = emulate_pop(ctxt, &selector, ctxt->op_bytes);
1478 if (rc != X86EMUL_CONTINUE)
1479 return rc;
1480
1481 rc = load_segment_descriptor(ctxt, (u16)selector, seg);
1482 return rc;
1483 }
1484
1485 static int em_pusha(struct x86_emulate_ctxt *ctxt)
1486 {
1487 unsigned long old_esp = ctxt->regs[VCPU_REGS_RSP];
1488 int rc = X86EMUL_CONTINUE;
1489 int reg = VCPU_REGS_RAX;
1490
1491 while (reg <= VCPU_REGS_RDI) {
1492 (reg == VCPU_REGS_RSP) ?
1493 (ctxt->src.val = old_esp) : (ctxt->src.val = ctxt->regs[reg]);
1494
1495 rc = em_push(ctxt);
1496 if (rc != X86EMUL_CONTINUE)
1497 return rc;
1498
1499 ++reg;
1500 }
1501
1502 return rc;
1503 }
1504
1505 static int em_pushf(struct x86_emulate_ctxt *ctxt)
1506 {
1507 ctxt->src.val = (unsigned long)ctxt->eflags;
1508 return em_push(ctxt);
1509 }
1510
1511 static int em_popa(struct x86_emulate_ctxt *ctxt)
1512 {
1513 int rc = X86EMUL_CONTINUE;
1514 int reg = VCPU_REGS_RDI;
1515
1516 while (reg >= VCPU_REGS_RAX) {
1517 if (reg == VCPU_REGS_RSP) {
1518 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP],
1519 ctxt->op_bytes);
1520 --reg;
1521 }
1522
1523 rc = emulate_pop(ctxt, &ctxt->regs[reg], ctxt->op_bytes);
1524 if (rc != X86EMUL_CONTINUE)
1525 break;
1526 --reg;
1527 }
1528 return rc;
1529 }
1530
1531 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq)
1532 {
1533 struct x86_emulate_ops *ops = ctxt->ops;
1534 int rc;
1535 struct desc_ptr dt;
1536 gva_t cs_addr;
1537 gva_t eip_addr;
1538 u16 cs, eip;
1539
1540 /* TODO: Add limit checks */
1541 ctxt->src.val = ctxt->eflags;
1542 rc = em_push(ctxt);
1543 if (rc != X86EMUL_CONTINUE)
1544 return rc;
1545
1546 ctxt->eflags &= ~(EFLG_IF | EFLG_TF | EFLG_AC);
1547
1548 ctxt->src.val = get_segment_selector(ctxt, VCPU_SREG_CS);
1549 rc = em_push(ctxt);
1550 if (rc != X86EMUL_CONTINUE)
1551 return rc;
1552
1553 ctxt->src.val = ctxt->_eip;
1554 rc = em_push(ctxt);
1555 if (rc != X86EMUL_CONTINUE)
1556 return rc;
1557
1558 ops->get_idt(ctxt, &dt);
1559
1560 eip_addr = dt.address + (irq << 2);
1561 cs_addr = dt.address + (irq << 2) + 2;
1562
1563 rc = ops->read_std(ctxt, cs_addr, &cs, 2, &ctxt->exception);
1564 if (rc != X86EMUL_CONTINUE)
1565 return rc;
1566
1567 rc = ops->read_std(ctxt, eip_addr, &eip, 2, &ctxt->exception);
1568 if (rc != X86EMUL_CONTINUE)
1569 return rc;
1570
1571 rc = load_segment_descriptor(ctxt, cs, VCPU_SREG_CS);
1572 if (rc != X86EMUL_CONTINUE)
1573 return rc;
1574
1575 ctxt->_eip = eip;
1576
1577 return rc;
1578 }
1579
1580 static int emulate_int(struct x86_emulate_ctxt *ctxt, int irq)
1581 {
1582 switch(ctxt->mode) {
1583 case X86EMUL_MODE_REAL:
1584 return emulate_int_real(ctxt, irq);
1585 case X86EMUL_MODE_VM86:
1586 case X86EMUL_MODE_PROT16:
1587 case X86EMUL_MODE_PROT32:
1588 case X86EMUL_MODE_PROT64:
1589 default:
1590 /* Protected mode interrupts unimplemented yet */
1591 return X86EMUL_UNHANDLEABLE;
1592 }
1593 }
1594
1595 static int emulate_iret_real(struct x86_emulate_ctxt *ctxt)
1596 {
1597 int rc = X86EMUL_CONTINUE;
1598 unsigned long temp_eip = 0;
1599 unsigned long temp_eflags = 0;
1600 unsigned long cs = 0;
1601 unsigned long mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_TF |
1602 EFLG_IF | EFLG_DF | EFLG_OF | EFLG_IOPL | EFLG_NT | EFLG_RF |
1603 EFLG_AC | EFLG_ID | (1 << 1); /* Last one is the reserved bit */
1604 unsigned long vm86_mask = EFLG_VM | EFLG_VIF | EFLG_VIP;
1605
1606 /* TODO: Add stack limit check */
1607
1608 rc = emulate_pop(ctxt, &temp_eip, ctxt->op_bytes);
1609
1610 if (rc != X86EMUL_CONTINUE)
1611 return rc;
1612
1613 if (temp_eip & ~0xffff)
1614 return emulate_gp(ctxt, 0);
1615
1616 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
1617
1618 if (rc != X86EMUL_CONTINUE)
1619 return rc;
1620
1621 rc = emulate_pop(ctxt, &temp_eflags, ctxt->op_bytes);
1622
1623 if (rc != X86EMUL_CONTINUE)
1624 return rc;
1625
1626 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
1627
1628 if (rc != X86EMUL_CONTINUE)
1629 return rc;
1630
1631 ctxt->_eip = temp_eip;
1632
1633
1634 if (ctxt->op_bytes == 4)
1635 ctxt->eflags = ((temp_eflags & mask) | (ctxt->eflags & vm86_mask));
1636 else if (ctxt->op_bytes == 2) {
1637 ctxt->eflags &= ~0xffff;
1638 ctxt->eflags |= temp_eflags;
1639 }
1640
1641 ctxt->eflags &= ~EFLG_RESERVED_ZEROS_MASK; /* Clear reserved zeros */
1642 ctxt->eflags |= EFLG_RESERVED_ONE_MASK;
1643
1644 return rc;
1645 }
1646
1647 static int em_iret(struct x86_emulate_ctxt *ctxt)
1648 {
1649 switch(ctxt->mode) {
1650 case X86EMUL_MODE_REAL:
1651 return emulate_iret_real(ctxt);
1652 case X86EMUL_MODE_VM86:
1653 case X86EMUL_MODE_PROT16:
1654 case X86EMUL_MODE_PROT32:
1655 case X86EMUL_MODE_PROT64:
1656 default:
1657 /* iret from protected mode unimplemented yet */
1658 return X86EMUL_UNHANDLEABLE;
1659 }
1660 }
1661
1662 static int em_jmp_far(struct x86_emulate_ctxt *ctxt)
1663 {
1664 int rc;
1665 unsigned short sel;
1666
1667 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
1668
1669 rc = load_segment_descriptor(ctxt, sel, VCPU_SREG_CS);
1670 if (rc != X86EMUL_CONTINUE)
1671 return rc;
1672
1673 ctxt->_eip = 0;
1674 memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
1675 return X86EMUL_CONTINUE;
1676 }
1677
1678 static int em_grp2(struct x86_emulate_ctxt *ctxt)
1679 {
1680 switch (ctxt->modrm_reg) {
1681 case 0: /* rol */
1682 emulate_2op_SrcB(ctxt, "rol");
1683 break;
1684 case 1: /* ror */
1685 emulate_2op_SrcB(ctxt, "ror");
1686 break;
1687 case 2: /* rcl */
1688 emulate_2op_SrcB(ctxt, "rcl");
1689 break;
1690 case 3: /* rcr */
1691 emulate_2op_SrcB(ctxt, "rcr");
1692 break;
1693 case 4: /* sal/shl */
1694 case 6: /* sal/shl */
1695 emulate_2op_SrcB(ctxt, "sal");
1696 break;
1697 case 5: /* shr */
1698 emulate_2op_SrcB(ctxt, "shr");
1699 break;
1700 case 7: /* sar */
1701 emulate_2op_SrcB(ctxt, "sar");
1702 break;
1703 }
1704 return X86EMUL_CONTINUE;
1705 }
1706
1707 static int em_not(struct x86_emulate_ctxt *ctxt)
1708 {
1709 ctxt->dst.val = ~ctxt->dst.val;
1710 return X86EMUL_CONTINUE;
1711 }
1712
1713 static int em_neg(struct x86_emulate_ctxt *ctxt)
1714 {
1715 emulate_1op(ctxt, "neg");
1716 return X86EMUL_CONTINUE;
1717 }
1718
1719 static int em_mul_ex(struct x86_emulate_ctxt *ctxt)
1720 {
1721 u8 ex = 0;
1722
1723 emulate_1op_rax_rdx(ctxt, "mul", ex);
1724 return X86EMUL_CONTINUE;
1725 }
1726
1727 static int em_imul_ex(struct x86_emulate_ctxt *ctxt)
1728 {
1729 u8 ex = 0;
1730
1731 emulate_1op_rax_rdx(ctxt, "imul", ex);
1732 return X86EMUL_CONTINUE;
1733 }
1734
1735 static int em_div_ex(struct x86_emulate_ctxt *ctxt)
1736 {
1737 u8 de = 0;
1738
1739 emulate_1op_rax_rdx(ctxt, "div", de);
1740 if (de)
1741 return emulate_de(ctxt);
1742 return X86EMUL_CONTINUE;
1743 }
1744
1745 static int em_idiv_ex(struct x86_emulate_ctxt *ctxt)
1746 {
1747 u8 de = 0;
1748
1749 emulate_1op_rax_rdx(ctxt, "idiv", de);
1750 if (de)
1751 return emulate_de(ctxt);
1752 return X86EMUL_CONTINUE;
1753 }
1754
1755 static int em_grp45(struct x86_emulate_ctxt *ctxt)
1756 {
1757 int rc = X86EMUL_CONTINUE;
1758
1759 switch (ctxt->modrm_reg) {
1760 case 0: /* inc */
1761 emulate_1op(ctxt, "inc");
1762 break;
1763 case 1: /* dec */
1764 emulate_1op(ctxt, "dec");
1765 break;
1766 case 2: /* call near abs */ {
1767 long int old_eip;
1768 old_eip = ctxt->_eip;
1769 ctxt->_eip = ctxt->src.val;
1770 ctxt->src.val = old_eip;
1771 rc = em_push(ctxt);
1772 break;
1773 }
1774 case 4: /* jmp abs */
1775 ctxt->_eip = ctxt->src.val;
1776 break;
1777 case 5: /* jmp far */
1778 rc = em_jmp_far(ctxt);
1779 break;
1780 case 6: /* push */
1781 rc = em_push(ctxt);
1782 break;
1783 }
1784 return rc;
1785 }
1786
1787 static int em_cmpxchg8b(struct x86_emulate_ctxt *ctxt)
1788 {
1789 u64 old = ctxt->dst.orig_val64;
1790
1791 if (((u32) (old >> 0) != (u32) ctxt->regs[VCPU_REGS_RAX]) ||
1792 ((u32) (old >> 32) != (u32) ctxt->regs[VCPU_REGS_RDX])) {
1793 ctxt->regs[VCPU_REGS_RAX] = (u32) (old >> 0);
1794 ctxt->regs[VCPU_REGS_RDX] = (u32) (old >> 32);
1795 ctxt->eflags &= ~EFLG_ZF;
1796 } else {
1797 ctxt->dst.val64 = ((u64)ctxt->regs[VCPU_REGS_RCX] << 32) |
1798 (u32) ctxt->regs[VCPU_REGS_RBX];
1799
1800 ctxt->eflags |= EFLG_ZF;
1801 }
1802 return X86EMUL_CONTINUE;
1803 }
1804
1805 static int em_ret(struct x86_emulate_ctxt *ctxt)
1806 {
1807 ctxt->dst.type = OP_REG;
1808 ctxt->dst.addr.reg = &ctxt->_eip;
1809 ctxt->dst.bytes = ctxt->op_bytes;
1810 return em_pop(ctxt);
1811 }
1812
1813 static int em_ret_far(struct x86_emulate_ctxt *ctxt)
1814 {
1815 int rc;
1816 unsigned long cs;
1817
1818 rc = emulate_pop(ctxt, &ctxt->_eip, ctxt->op_bytes);
1819 if (rc != X86EMUL_CONTINUE)
1820 return rc;
1821 if (ctxt->op_bytes == 4)
1822 ctxt->_eip = (u32)ctxt->_eip;
1823 rc = emulate_pop(ctxt, &cs, ctxt->op_bytes);
1824 if (rc != X86EMUL_CONTINUE)
1825 return rc;
1826 rc = load_segment_descriptor(ctxt, (u16)cs, VCPU_SREG_CS);
1827 return rc;
1828 }
1829
1830 static int em_cmpxchg(struct x86_emulate_ctxt *ctxt)
1831 {
1832 /* Save real source value, then compare EAX against destination. */
1833 ctxt->src.orig_val = ctxt->src.val;
1834 ctxt->src.val = ctxt->regs[VCPU_REGS_RAX];
1835 emulate_2op_SrcV(ctxt, "cmp");
1836
1837 if (ctxt->eflags & EFLG_ZF) {
1838 /* Success: write back to memory. */
1839 ctxt->dst.val = ctxt->src.orig_val;
1840 } else {
1841 /* Failure: write the value we saw to EAX. */
1842 ctxt->dst.type = OP_REG;
1843 ctxt->dst.addr.reg = (unsigned long *)&ctxt->regs[VCPU_REGS_RAX];
1844 }
1845 return X86EMUL_CONTINUE;
1846 }
1847
1848 static int em_lseg(struct x86_emulate_ctxt *ctxt)
1849 {
1850 int seg = ctxt->src2.val;
1851 unsigned short sel;
1852 int rc;
1853
1854 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
1855
1856 rc = load_segment_descriptor(ctxt, sel, seg);
1857 if (rc != X86EMUL_CONTINUE)
1858 return rc;
1859
1860 ctxt->dst.val = ctxt->src.val;
1861 return rc;
1862 }
1863
1864 static void
1865 setup_syscalls_segments(struct x86_emulate_ctxt *ctxt,
1866 struct desc_struct *cs, struct desc_struct *ss)
1867 {
1868 u16 selector;
1869
1870 memset(cs, 0, sizeof(struct desc_struct));
1871 ctxt->ops->get_segment(ctxt, &selector, cs, NULL, VCPU_SREG_CS);
1872 memset(ss, 0, sizeof(struct desc_struct));
1873
1874 cs->l = 0; /* will be adjusted later */
1875 set_desc_base(cs, 0); /* flat segment */
1876 cs->g = 1; /* 4kb granularity */
1877 set_desc_limit(cs, 0xfffff); /* 4GB limit */
1878 cs->type = 0x0b; /* Read, Execute, Accessed */
1879 cs->s = 1;
1880 cs->dpl = 0; /* will be adjusted later */
1881 cs->p = 1;
1882 cs->d = 1;
1883
1884 set_desc_base(ss, 0); /* flat segment */
1885 set_desc_limit(ss, 0xfffff); /* 4GB limit */
1886 ss->g = 1; /* 4kb granularity */
1887 ss->s = 1;
1888 ss->type = 0x03; /* Read/Write, Accessed */
1889 ss->d = 1; /* 32bit stack segment */
1890 ss->dpl = 0;
1891 ss->p = 1;
1892 }
1893
1894 static bool em_syscall_is_enabled(struct x86_emulate_ctxt *ctxt)
1895 {
1896 struct x86_emulate_ops *ops = ctxt->ops;
1897 u32 eax, ebx, ecx, edx;
1898
1899 /*
1900 * syscall should always be enabled in longmode - so only become
1901 * vendor specific (cpuid) if other modes are active...
1902 */
1903 if (ctxt->mode == X86EMUL_MODE_PROT64)
1904 return true;
1905
1906 eax = 0x00000000;
1907 ecx = 0x00000000;
1908 if (ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx)) {
1909 /*
1910 * Intel ("GenuineIntel")
1911 * remark: Intel CPUs only support "syscall" in 64bit
1912 * longmode. Also an 64bit guest with a
1913 * 32bit compat-app running will #UD !! While this
1914 * behaviour can be fixed (by emulating) into AMD
1915 * response - CPUs of AMD can't behave like Intel.
1916 */
1917 if (ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx &&
1918 ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx &&
1919 edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx)
1920 return false;
1921
1922 /* AMD ("AuthenticAMD") */
1923 if (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx &&
1924 ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx &&
1925 edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx)
1926 return true;
1927
1928 /* AMD ("AMDisbetter!") */
1929 if (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx &&
1930 ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx &&
1931 edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx)
1932 return true;
1933 }
1934
1935 /* default: (not Intel, not AMD), apply Intel's stricter rules... */
1936 return false;
1937 }
1938
1939 static int em_syscall(struct x86_emulate_ctxt *ctxt)
1940 {
1941 struct x86_emulate_ops *ops = ctxt->ops;
1942 struct desc_struct cs, ss;
1943 u64 msr_data;
1944 u16 cs_sel, ss_sel;
1945 u64 efer = 0;
1946
1947 /* syscall is not available in real mode */
1948 if (ctxt->mode == X86EMUL_MODE_REAL ||
1949 ctxt->mode == X86EMUL_MODE_VM86)
1950 return emulate_ud(ctxt);
1951
1952 if (!(em_syscall_is_enabled(ctxt)))
1953 return emulate_ud(ctxt);
1954
1955 ops->get_msr(ctxt, MSR_EFER, &efer);
1956 setup_syscalls_segments(ctxt, &cs, &ss);
1957
1958 if (!(efer & EFER_SCE))
1959 return emulate_ud(ctxt);
1960
1961 ops->get_msr(ctxt, MSR_STAR, &msr_data);
1962 msr_data >>= 32;
1963 cs_sel = (u16)(msr_data & 0xfffc);
1964 ss_sel = (u16)(msr_data + 8);
1965
1966 if (efer & EFER_LMA) {
1967 cs.d = 0;
1968 cs.l = 1;
1969 }
1970 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
1971 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
1972
1973 ctxt->regs[VCPU_REGS_RCX] = ctxt->_eip;
1974 if (efer & EFER_LMA) {
1975 #ifdef CONFIG_X86_64
1976 ctxt->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF;
1977
1978 ops->get_msr(ctxt,
1979 ctxt->mode == X86EMUL_MODE_PROT64 ?
1980 MSR_LSTAR : MSR_CSTAR, &msr_data);
1981 ctxt->_eip = msr_data;
1982
1983 ops->get_msr(ctxt, MSR_SYSCALL_MASK, &msr_data);
1984 ctxt->eflags &= ~(msr_data | EFLG_RF);
1985 #endif
1986 } else {
1987 /* legacy mode */
1988 ops->get_msr(ctxt, MSR_STAR, &msr_data);
1989 ctxt->_eip = (u32)msr_data;
1990
1991 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
1992 }
1993
1994 return X86EMUL_CONTINUE;
1995 }
1996
1997 static int em_sysenter(struct x86_emulate_ctxt *ctxt)
1998 {
1999 struct x86_emulate_ops *ops = ctxt->ops;
2000 struct desc_struct cs, ss;
2001 u64 msr_data;
2002 u16 cs_sel, ss_sel;
2003 u64 efer = 0;
2004
2005 ops->get_msr(ctxt, MSR_EFER, &efer);
2006 /* inject #GP if in real mode */
2007 if (ctxt->mode == X86EMUL_MODE_REAL)
2008 return emulate_gp(ctxt, 0);
2009
2010 /* XXX sysenter/sysexit have not been tested in 64bit mode.
2011 * Therefore, we inject an #UD.
2012 */
2013 if (ctxt->mode == X86EMUL_MODE_PROT64)
2014 return emulate_ud(ctxt);
2015
2016 setup_syscalls_segments(ctxt, &cs, &ss);
2017
2018 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2019 switch (ctxt->mode) {
2020 case X86EMUL_MODE_PROT32:
2021 if ((msr_data & 0xfffc) == 0x0)
2022 return emulate_gp(ctxt, 0);
2023 break;
2024 case X86EMUL_MODE_PROT64:
2025 if (msr_data == 0x0)
2026 return emulate_gp(ctxt, 0);
2027 break;
2028 }
2029
2030 ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF);
2031 cs_sel = (u16)msr_data;
2032 cs_sel &= ~SELECTOR_RPL_MASK;
2033 ss_sel = cs_sel + 8;
2034 ss_sel &= ~SELECTOR_RPL_MASK;
2035 if (ctxt->mode == X86EMUL_MODE_PROT64 || (efer & EFER_LMA)) {
2036 cs.d = 0;
2037 cs.l = 1;
2038 }
2039
2040 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2041 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2042
2043 ops->get_msr(ctxt, MSR_IA32_SYSENTER_EIP, &msr_data);
2044 ctxt->_eip = msr_data;
2045
2046 ops->get_msr(ctxt, MSR_IA32_SYSENTER_ESP, &msr_data);
2047 ctxt->regs[VCPU_REGS_RSP] = msr_data;
2048
2049 return X86EMUL_CONTINUE;
2050 }
2051
2052 static int em_sysexit(struct x86_emulate_ctxt *ctxt)
2053 {
2054 struct x86_emulate_ops *ops = ctxt->ops;
2055 struct desc_struct cs, ss;
2056 u64 msr_data;
2057 int usermode;
2058 u16 cs_sel = 0, ss_sel = 0;
2059
2060 /* inject #GP if in real mode or Virtual 8086 mode */
2061 if (ctxt->mode == X86EMUL_MODE_REAL ||
2062 ctxt->mode == X86EMUL_MODE_VM86)
2063 return emulate_gp(ctxt, 0);
2064
2065 setup_syscalls_segments(ctxt, &cs, &ss);
2066
2067 if ((ctxt->rex_prefix & 0x8) != 0x0)
2068 usermode = X86EMUL_MODE_PROT64;
2069 else
2070 usermode = X86EMUL_MODE_PROT32;
2071
2072 cs.dpl = 3;
2073 ss.dpl = 3;
2074 ops->get_msr(ctxt, MSR_IA32_SYSENTER_CS, &msr_data);
2075 switch (usermode) {
2076 case X86EMUL_MODE_PROT32:
2077 cs_sel = (u16)(msr_data + 16);
2078 if ((msr_data & 0xfffc) == 0x0)
2079 return emulate_gp(ctxt, 0);
2080 ss_sel = (u16)(msr_data + 24);
2081 break;
2082 case X86EMUL_MODE_PROT64:
2083 cs_sel = (u16)(msr_data + 32);
2084 if (msr_data == 0x0)
2085 return emulate_gp(ctxt, 0);
2086 ss_sel = cs_sel + 8;
2087 cs.d = 0;
2088 cs.l = 1;
2089 break;
2090 }
2091 cs_sel |= SELECTOR_RPL_MASK;
2092 ss_sel |= SELECTOR_RPL_MASK;
2093
2094 ops->set_segment(ctxt, cs_sel, &cs, 0, VCPU_SREG_CS);
2095 ops->set_segment(ctxt, ss_sel, &ss, 0, VCPU_SREG_SS);
2096
2097 ctxt->_eip = ctxt->regs[VCPU_REGS_RDX];
2098 ctxt->regs[VCPU_REGS_RSP] = ctxt->regs[VCPU_REGS_RCX];
2099
2100 return X86EMUL_CONTINUE;
2101 }
2102
2103 static bool emulator_bad_iopl(struct x86_emulate_ctxt *ctxt)
2104 {
2105 int iopl;
2106 if (ctxt->mode == X86EMUL_MODE_REAL)
2107 return false;
2108 if (ctxt->mode == X86EMUL_MODE_VM86)
2109 return true;
2110 iopl = (ctxt->eflags & X86_EFLAGS_IOPL) >> IOPL_SHIFT;
2111 return ctxt->ops->cpl(ctxt) > iopl;
2112 }
2113
2114 static bool emulator_io_port_access_allowed(struct x86_emulate_ctxt *ctxt,
2115 u16 port, u16 len)
2116 {
2117 struct x86_emulate_ops *ops = ctxt->ops;
2118 struct desc_struct tr_seg;
2119 u32 base3;
2120 int r;
2121 u16 tr, io_bitmap_ptr, perm, bit_idx = port & 0x7;
2122 unsigned mask = (1 << len) - 1;
2123 unsigned long base;
2124
2125 ops->get_segment(ctxt, &tr, &tr_seg, &base3, VCPU_SREG_TR);
2126 if (!tr_seg.p)
2127 return false;
2128 if (desc_limit_scaled(&tr_seg) < 103)
2129 return false;
2130 base = get_desc_base(&tr_seg);
2131 #ifdef CONFIG_X86_64
2132 base |= ((u64)base3) << 32;
2133 #endif
2134 r = ops->read_std(ctxt, base + 102, &io_bitmap_ptr, 2, NULL);
2135 if (r != X86EMUL_CONTINUE)
2136 return false;
2137 if (io_bitmap_ptr + port/8 > desc_limit_scaled(&tr_seg))
2138 return false;
2139 r = ops->read_std(ctxt, base + io_bitmap_ptr + port/8, &perm, 2, NULL);
2140 if (r != X86EMUL_CONTINUE)
2141 return false;
2142 if ((perm >> bit_idx) & mask)
2143 return false;
2144 return true;
2145 }
2146
2147 static bool emulator_io_permited(struct x86_emulate_ctxt *ctxt,
2148 u16 port, u16 len)
2149 {
2150 if (ctxt->perm_ok)
2151 return true;
2152
2153 if (emulator_bad_iopl(ctxt))
2154 if (!emulator_io_port_access_allowed(ctxt, port, len))
2155 return false;
2156
2157 ctxt->perm_ok = true;
2158
2159 return true;
2160 }
2161
2162 static void save_state_to_tss16(struct x86_emulate_ctxt *ctxt,
2163 struct tss_segment_16 *tss)
2164 {
2165 tss->ip = ctxt->_eip;
2166 tss->flag = ctxt->eflags;
2167 tss->ax = ctxt->regs[VCPU_REGS_RAX];
2168 tss->cx = ctxt->regs[VCPU_REGS_RCX];
2169 tss->dx = ctxt->regs[VCPU_REGS_RDX];
2170 tss->bx = ctxt->regs[VCPU_REGS_RBX];
2171 tss->sp = ctxt->regs[VCPU_REGS_RSP];
2172 tss->bp = ctxt->regs[VCPU_REGS_RBP];
2173 tss->si = ctxt->regs[VCPU_REGS_RSI];
2174 tss->di = ctxt->regs[VCPU_REGS_RDI];
2175
2176 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2177 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2178 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2179 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2180 tss->ldt = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2181 }
2182
2183 static int load_state_from_tss16(struct x86_emulate_ctxt *ctxt,
2184 struct tss_segment_16 *tss)
2185 {
2186 int ret;
2187
2188 ctxt->_eip = tss->ip;
2189 ctxt->eflags = tss->flag | 2;
2190 ctxt->regs[VCPU_REGS_RAX] = tss->ax;
2191 ctxt->regs[VCPU_REGS_RCX] = tss->cx;
2192 ctxt->regs[VCPU_REGS_RDX] = tss->dx;
2193 ctxt->regs[VCPU_REGS_RBX] = tss->bx;
2194 ctxt->regs[VCPU_REGS_RSP] = tss->sp;
2195 ctxt->regs[VCPU_REGS_RBP] = tss->bp;
2196 ctxt->regs[VCPU_REGS_RSI] = tss->si;
2197 ctxt->regs[VCPU_REGS_RDI] = tss->di;
2198
2199 /*
2200 * SDM says that segment selectors are loaded before segment
2201 * descriptors
2202 */
2203 set_segment_selector(ctxt, tss->ldt, VCPU_SREG_LDTR);
2204 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2205 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2206 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2207 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2208
2209 /*
2210 * Now load segment descriptors. If fault happenes at this stage
2211 * it is handled in a context of new task
2212 */
2213 ret = load_segment_descriptor(ctxt, tss->ldt, VCPU_SREG_LDTR);
2214 if (ret != X86EMUL_CONTINUE)
2215 return ret;
2216 ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
2217 if (ret != X86EMUL_CONTINUE)
2218 return ret;
2219 ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
2220 if (ret != X86EMUL_CONTINUE)
2221 return ret;
2222 ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
2223 if (ret != X86EMUL_CONTINUE)
2224 return ret;
2225 ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
2226 if (ret != X86EMUL_CONTINUE)
2227 return ret;
2228
2229 return X86EMUL_CONTINUE;
2230 }
2231
2232 static int task_switch_16(struct x86_emulate_ctxt *ctxt,
2233 u16 tss_selector, u16 old_tss_sel,
2234 ulong old_tss_base, struct desc_struct *new_desc)
2235 {
2236 struct x86_emulate_ops *ops = ctxt->ops;
2237 struct tss_segment_16 tss_seg;
2238 int ret;
2239 u32 new_tss_base = get_desc_base(new_desc);
2240
2241 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2242 &ctxt->exception);
2243 if (ret != X86EMUL_CONTINUE)
2244 /* FIXME: need to provide precise fault address */
2245 return ret;
2246
2247 save_state_to_tss16(ctxt, &tss_seg);
2248
2249 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2250 &ctxt->exception);
2251 if (ret != X86EMUL_CONTINUE)
2252 /* FIXME: need to provide precise fault address */
2253 return ret;
2254
2255 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2256 &ctxt->exception);
2257 if (ret != X86EMUL_CONTINUE)
2258 /* FIXME: need to provide precise fault address */
2259 return ret;
2260
2261 if (old_tss_sel != 0xffff) {
2262 tss_seg.prev_task_link = old_tss_sel;
2263
2264 ret = ops->write_std(ctxt, new_tss_base,
2265 &tss_seg.prev_task_link,
2266 sizeof tss_seg.prev_task_link,
2267 &ctxt->exception);
2268 if (ret != X86EMUL_CONTINUE)
2269 /* FIXME: need to provide precise fault address */
2270 return ret;
2271 }
2272
2273 return load_state_from_tss16(ctxt, &tss_seg);
2274 }
2275
2276 static void save_state_to_tss32(struct x86_emulate_ctxt *ctxt,
2277 struct tss_segment_32 *tss)
2278 {
2279 tss->cr3 = ctxt->ops->get_cr(ctxt, 3);
2280 tss->eip = ctxt->_eip;
2281 tss->eflags = ctxt->eflags;
2282 tss->eax = ctxt->regs[VCPU_REGS_RAX];
2283 tss->ecx = ctxt->regs[VCPU_REGS_RCX];
2284 tss->edx = ctxt->regs[VCPU_REGS_RDX];
2285 tss->ebx = ctxt->regs[VCPU_REGS_RBX];
2286 tss->esp = ctxt->regs[VCPU_REGS_RSP];
2287 tss->ebp = ctxt->regs[VCPU_REGS_RBP];
2288 tss->esi = ctxt->regs[VCPU_REGS_RSI];
2289 tss->edi = ctxt->regs[VCPU_REGS_RDI];
2290
2291 tss->es = get_segment_selector(ctxt, VCPU_SREG_ES);
2292 tss->cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2293 tss->ss = get_segment_selector(ctxt, VCPU_SREG_SS);
2294 tss->ds = get_segment_selector(ctxt, VCPU_SREG_DS);
2295 tss->fs = get_segment_selector(ctxt, VCPU_SREG_FS);
2296 tss->gs = get_segment_selector(ctxt, VCPU_SREG_GS);
2297 tss->ldt_selector = get_segment_selector(ctxt, VCPU_SREG_LDTR);
2298 }
2299
2300 static int load_state_from_tss32(struct x86_emulate_ctxt *ctxt,
2301 struct tss_segment_32 *tss)
2302 {
2303 int ret;
2304
2305 if (ctxt->ops->set_cr(ctxt, 3, tss->cr3))
2306 return emulate_gp(ctxt, 0);
2307 ctxt->_eip = tss->eip;
2308 ctxt->eflags = tss->eflags | 2;
2309 ctxt->regs[VCPU_REGS_RAX] = tss->eax;
2310 ctxt->regs[VCPU_REGS_RCX] = tss->ecx;
2311 ctxt->regs[VCPU_REGS_RDX] = tss->edx;
2312 ctxt->regs[VCPU_REGS_RBX] = tss->ebx;
2313 ctxt->regs[VCPU_REGS_RSP] = tss->esp;
2314 ctxt->regs[VCPU_REGS_RBP] = tss->ebp;
2315 ctxt->regs[VCPU_REGS_RSI] = tss->esi;
2316 ctxt->regs[VCPU_REGS_RDI] = tss->edi;
2317
2318 /*
2319 * SDM says that segment selectors are loaded before segment
2320 * descriptors
2321 */
2322 set_segment_selector(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
2323 set_segment_selector(ctxt, tss->es, VCPU_SREG_ES);
2324 set_segment_selector(ctxt, tss->cs, VCPU_SREG_CS);
2325 set_segment_selector(ctxt, tss->ss, VCPU_SREG_SS);
2326 set_segment_selector(ctxt, tss->ds, VCPU_SREG_DS);
2327 set_segment_selector(ctxt, tss->fs, VCPU_SREG_FS);
2328 set_segment_selector(ctxt, tss->gs, VCPU_SREG_GS);
2329
2330 /*
2331 * Now load segment descriptors. If fault happenes at this stage
2332 * it is handled in a context of new task
2333 */
2334 ret = load_segment_descriptor(ctxt, tss->ldt_selector, VCPU_SREG_LDTR);
2335 if (ret != X86EMUL_CONTINUE)
2336 return ret;
2337 ret = load_segment_descriptor(ctxt, tss->es, VCPU_SREG_ES);
2338 if (ret != X86EMUL_CONTINUE)
2339 return ret;
2340 ret = load_segment_descriptor(ctxt, tss->cs, VCPU_SREG_CS);
2341 if (ret != X86EMUL_CONTINUE)
2342 return ret;
2343 ret = load_segment_descriptor(ctxt, tss->ss, VCPU_SREG_SS);
2344 if (ret != X86EMUL_CONTINUE)
2345 return ret;
2346 ret = load_segment_descriptor(ctxt, tss->ds, VCPU_SREG_DS);
2347 if (ret != X86EMUL_CONTINUE)
2348 return ret;
2349 ret = load_segment_descriptor(ctxt, tss->fs, VCPU_SREG_FS);
2350 if (ret != X86EMUL_CONTINUE)
2351 return ret;
2352 ret = load_segment_descriptor(ctxt, tss->gs, VCPU_SREG_GS);
2353 if (ret != X86EMUL_CONTINUE)
2354 return ret;
2355
2356 return X86EMUL_CONTINUE;
2357 }
2358
2359 static int task_switch_32(struct x86_emulate_ctxt *ctxt,
2360 u16 tss_selector, u16 old_tss_sel,
2361 ulong old_tss_base, struct desc_struct *new_desc)
2362 {
2363 struct x86_emulate_ops *ops = ctxt->ops;
2364 struct tss_segment_32 tss_seg;
2365 int ret;
2366 u32 new_tss_base = get_desc_base(new_desc);
2367
2368 ret = ops->read_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2369 &ctxt->exception);
2370 if (ret != X86EMUL_CONTINUE)
2371 /* FIXME: need to provide precise fault address */
2372 return ret;
2373
2374 save_state_to_tss32(ctxt, &tss_seg);
2375
2376 ret = ops->write_std(ctxt, old_tss_base, &tss_seg, sizeof tss_seg,
2377 &ctxt->exception);
2378 if (ret != X86EMUL_CONTINUE)
2379 /* FIXME: need to provide precise fault address */
2380 return ret;
2381
2382 ret = ops->read_std(ctxt, new_tss_base, &tss_seg, sizeof tss_seg,
2383 &ctxt->exception);
2384 if (ret != X86EMUL_CONTINUE)
2385 /* FIXME: need to provide precise fault address */
2386 return ret;
2387
2388 if (old_tss_sel != 0xffff) {
2389 tss_seg.prev_task_link = old_tss_sel;
2390
2391 ret = ops->write_std(ctxt, new_tss_base,
2392 &tss_seg.prev_task_link,
2393 sizeof tss_seg.prev_task_link,
2394 &ctxt->exception);
2395 if (ret != X86EMUL_CONTINUE)
2396 /* FIXME: need to provide precise fault address */
2397 return ret;
2398 }
2399
2400 return load_state_from_tss32(ctxt, &tss_seg);
2401 }
2402
2403 static int emulator_do_task_switch(struct x86_emulate_ctxt *ctxt,
2404 u16 tss_selector, int reason,
2405 bool has_error_code, u32 error_code)
2406 {
2407 struct x86_emulate_ops *ops = ctxt->ops;
2408 struct desc_struct curr_tss_desc, next_tss_desc;
2409 int ret;
2410 u16 old_tss_sel = get_segment_selector(ctxt, VCPU_SREG_TR);
2411 ulong old_tss_base =
2412 ops->get_cached_segment_base(ctxt, VCPU_SREG_TR);
2413 u32 desc_limit;
2414
2415 /* FIXME: old_tss_base == ~0 ? */
2416
2417 ret = read_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
2418 if (ret != X86EMUL_CONTINUE)
2419 return ret;
2420 ret = read_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
2421 if (ret != X86EMUL_CONTINUE)
2422 return ret;
2423
2424 /* FIXME: check that next_tss_desc is tss */
2425
2426 if (reason != TASK_SWITCH_IRET) {
2427 if ((tss_selector & 3) > next_tss_desc.dpl ||
2428 ops->cpl(ctxt) > next_tss_desc.dpl)
2429 return emulate_gp(ctxt, 0);
2430 }
2431
2432 desc_limit = desc_limit_scaled(&next_tss_desc);
2433 if (!next_tss_desc.p ||
2434 ((desc_limit < 0x67 && (next_tss_desc.type & 8)) ||
2435 desc_limit < 0x2b)) {
2436 emulate_ts(ctxt, tss_selector & 0xfffc);
2437 return X86EMUL_PROPAGATE_FAULT;
2438 }
2439
2440 if (reason == TASK_SWITCH_IRET || reason == TASK_SWITCH_JMP) {
2441 curr_tss_desc.type &= ~(1 << 1); /* clear busy flag */
2442 write_segment_descriptor(ctxt, old_tss_sel, &curr_tss_desc);
2443 }
2444
2445 if (reason == TASK_SWITCH_IRET)
2446 ctxt->eflags = ctxt->eflags & ~X86_EFLAGS_NT;
2447
2448 /* set back link to prev task only if NT bit is set in eflags
2449 note that old_tss_sel is not used afetr this point */
2450 if (reason != TASK_SWITCH_CALL && reason != TASK_SWITCH_GATE)
2451 old_tss_sel = 0xffff;
2452
2453 if (next_tss_desc.type & 8)
2454 ret = task_switch_32(ctxt, tss_selector, old_tss_sel,
2455 old_tss_base, &next_tss_desc);
2456 else
2457 ret = task_switch_16(ctxt, tss_selector, old_tss_sel,
2458 old_tss_base, &next_tss_desc);
2459 if (ret != X86EMUL_CONTINUE)
2460 return ret;
2461
2462 if (reason == TASK_SWITCH_CALL || reason == TASK_SWITCH_GATE)
2463 ctxt->eflags = ctxt->eflags | X86_EFLAGS_NT;
2464
2465 if (reason != TASK_SWITCH_IRET) {
2466 next_tss_desc.type |= (1 << 1); /* set busy flag */
2467 write_segment_descriptor(ctxt, tss_selector, &next_tss_desc);
2468 }
2469
2470 ops->set_cr(ctxt, 0, ops->get_cr(ctxt, 0) | X86_CR0_TS);
2471 ops->set_segment(ctxt, tss_selector, &next_tss_desc, 0, VCPU_SREG_TR);
2472
2473 if (has_error_code) {
2474 ctxt->op_bytes = ctxt->ad_bytes = (next_tss_desc.type & 8) ? 4 : 2;
2475 ctxt->lock_prefix = 0;
2476 ctxt->src.val = (unsigned long) error_code;
2477 ret = em_push(ctxt);
2478 }
2479
2480 return ret;
2481 }
2482
2483 int emulator_task_switch(struct x86_emulate_ctxt *ctxt,
2484 u16 tss_selector, int reason,
2485 bool has_error_code, u32 error_code)
2486 {
2487 int rc;
2488
2489 ctxt->_eip = ctxt->eip;
2490 ctxt->dst.type = OP_NONE;
2491
2492 rc = emulator_do_task_switch(ctxt, tss_selector, reason,
2493 has_error_code, error_code);
2494
2495 if (rc == X86EMUL_CONTINUE)
2496 ctxt->eip = ctxt->_eip;
2497
2498 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
2499 }
2500
2501 static void string_addr_inc(struct x86_emulate_ctxt *ctxt, unsigned seg,
2502 int reg, struct operand *op)
2503 {
2504 int df = (ctxt->eflags & EFLG_DF) ? -1 : 1;
2505
2506 register_address_increment(ctxt, &ctxt->regs[reg], df * op->bytes);
2507 op->addr.mem.ea = register_address(ctxt, ctxt->regs[reg]);
2508 op->addr.mem.seg = seg;
2509 }
2510
2511 static int em_das(struct x86_emulate_ctxt *ctxt)
2512 {
2513 u8 al, old_al;
2514 bool af, cf, old_cf;
2515
2516 cf = ctxt->eflags & X86_EFLAGS_CF;
2517 al = ctxt->dst.val;
2518
2519 old_al = al;
2520 old_cf = cf;
2521 cf = false;
2522 af = ctxt->eflags & X86_EFLAGS_AF;
2523 if ((al & 0x0f) > 9 || af) {
2524 al -= 6;
2525 cf = old_cf | (al >= 250);
2526 af = true;
2527 } else {
2528 af = false;
2529 }
2530 if (old_al > 0x99 || old_cf) {
2531 al -= 0x60;
2532 cf = true;
2533 }
2534
2535 ctxt->dst.val = al;
2536 /* Set PF, ZF, SF */
2537 ctxt->src.type = OP_IMM;
2538 ctxt->src.val = 0;
2539 ctxt->src.bytes = 1;
2540 emulate_2op_SrcV(ctxt, "or");
2541 ctxt->eflags &= ~(X86_EFLAGS_AF | X86_EFLAGS_CF);
2542 if (cf)
2543 ctxt->eflags |= X86_EFLAGS_CF;
2544 if (af)
2545 ctxt->eflags |= X86_EFLAGS_AF;
2546 return X86EMUL_CONTINUE;
2547 }
2548
2549 static int em_call(struct x86_emulate_ctxt *ctxt)
2550 {
2551 long rel = ctxt->src.val;
2552
2553 ctxt->src.val = (unsigned long)ctxt->_eip;
2554 jmp_rel(ctxt, rel);
2555 return em_push(ctxt);
2556 }
2557
2558 static int em_call_far(struct x86_emulate_ctxt *ctxt)
2559 {
2560 u16 sel, old_cs;
2561 ulong old_eip;
2562 int rc;
2563
2564 old_cs = get_segment_selector(ctxt, VCPU_SREG_CS);
2565 old_eip = ctxt->_eip;
2566
2567 memcpy(&sel, ctxt->src.valptr + ctxt->op_bytes, 2);
2568 if (load_segment_descriptor(ctxt, sel, VCPU_SREG_CS))
2569 return X86EMUL_CONTINUE;
2570
2571 ctxt->_eip = 0;
2572 memcpy(&ctxt->_eip, ctxt->src.valptr, ctxt->op_bytes);
2573
2574 ctxt->src.val = old_cs;
2575 rc = em_push(ctxt);
2576 if (rc != X86EMUL_CONTINUE)
2577 return rc;
2578
2579 ctxt->src.val = old_eip;
2580 return em_push(ctxt);
2581 }
2582
2583 static int em_ret_near_imm(struct x86_emulate_ctxt *ctxt)
2584 {
2585 int rc;
2586
2587 ctxt->dst.type = OP_REG;
2588 ctxt->dst.addr.reg = &ctxt->_eip;
2589 ctxt->dst.bytes = ctxt->op_bytes;
2590 rc = emulate_pop(ctxt, &ctxt->dst.val, ctxt->op_bytes);
2591 if (rc != X86EMUL_CONTINUE)
2592 return rc;
2593 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RSP], ctxt->src.val);
2594 return X86EMUL_CONTINUE;
2595 }
2596
2597 static int em_add(struct x86_emulate_ctxt *ctxt)
2598 {
2599 emulate_2op_SrcV(ctxt, "add");
2600 return X86EMUL_CONTINUE;
2601 }
2602
2603 static int em_or(struct x86_emulate_ctxt *ctxt)
2604 {
2605 emulate_2op_SrcV(ctxt, "or");
2606 return X86EMUL_CONTINUE;
2607 }
2608
2609 static int em_adc(struct x86_emulate_ctxt *ctxt)
2610 {
2611 emulate_2op_SrcV(ctxt, "adc");
2612 return X86EMUL_CONTINUE;
2613 }
2614
2615 static int em_sbb(struct x86_emulate_ctxt *ctxt)
2616 {
2617 emulate_2op_SrcV(ctxt, "sbb");
2618 return X86EMUL_CONTINUE;
2619 }
2620
2621 static int em_and(struct x86_emulate_ctxt *ctxt)
2622 {
2623 emulate_2op_SrcV(ctxt, "and");
2624 return X86EMUL_CONTINUE;
2625 }
2626
2627 static int em_sub(struct x86_emulate_ctxt *ctxt)
2628 {
2629 emulate_2op_SrcV(ctxt, "sub");
2630 return X86EMUL_CONTINUE;
2631 }
2632
2633 static int em_xor(struct x86_emulate_ctxt *ctxt)
2634 {
2635 emulate_2op_SrcV(ctxt, "xor");
2636 return X86EMUL_CONTINUE;
2637 }
2638
2639 static int em_cmp(struct x86_emulate_ctxt *ctxt)
2640 {
2641 emulate_2op_SrcV(ctxt, "cmp");
2642 /* Disable writeback. */
2643 ctxt->dst.type = OP_NONE;
2644 return X86EMUL_CONTINUE;
2645 }
2646
2647 static int em_test(struct x86_emulate_ctxt *ctxt)
2648 {
2649 emulate_2op_SrcV(ctxt, "test");
2650 /* Disable writeback. */
2651 ctxt->dst.type = OP_NONE;
2652 return X86EMUL_CONTINUE;
2653 }
2654
2655 static int em_xchg(struct x86_emulate_ctxt *ctxt)
2656 {
2657 /* Write back the register source. */
2658 ctxt->src.val = ctxt->dst.val;
2659 write_register_operand(&ctxt->src);
2660
2661 /* Write back the memory destination with implicit LOCK prefix. */
2662 ctxt->dst.val = ctxt->src.orig_val;
2663 ctxt->lock_prefix = 1;
2664 return X86EMUL_CONTINUE;
2665 }
2666
2667 static int em_imul(struct x86_emulate_ctxt *ctxt)
2668 {
2669 emulate_2op_SrcV_nobyte(ctxt, "imul");
2670 return X86EMUL_CONTINUE;
2671 }
2672
2673 static int em_imul_3op(struct x86_emulate_ctxt *ctxt)
2674 {
2675 ctxt->dst.val = ctxt->src2.val;
2676 return em_imul(ctxt);
2677 }
2678
2679 static int em_cwd(struct x86_emulate_ctxt *ctxt)
2680 {
2681 ctxt->dst.type = OP_REG;
2682 ctxt->dst.bytes = ctxt->src.bytes;
2683 ctxt->dst.addr.reg = &ctxt->regs[VCPU_REGS_RDX];
2684 ctxt->dst.val = ~((ctxt->src.val >> (ctxt->src.bytes * 8 - 1)) - 1);
2685
2686 return X86EMUL_CONTINUE;
2687 }
2688
2689 static int em_rdtsc(struct x86_emulate_ctxt *ctxt)
2690 {
2691 u64 tsc = 0;
2692
2693 ctxt->ops->get_msr(ctxt, MSR_IA32_TSC, &tsc);
2694 ctxt->regs[VCPU_REGS_RAX] = (u32)tsc;
2695 ctxt->regs[VCPU_REGS_RDX] = tsc >> 32;
2696 return X86EMUL_CONTINUE;
2697 }
2698
2699 static int em_rdpmc(struct x86_emulate_ctxt *ctxt)
2700 {
2701 u64 pmc;
2702
2703 if (ctxt->ops->read_pmc(ctxt, ctxt->regs[VCPU_REGS_RCX], &pmc))
2704 return emulate_gp(ctxt, 0);
2705 ctxt->regs[VCPU_REGS_RAX] = (u32)pmc;
2706 ctxt->regs[VCPU_REGS_RDX] = pmc >> 32;
2707 return X86EMUL_CONTINUE;
2708 }
2709
2710 static int em_mov(struct x86_emulate_ctxt *ctxt)
2711 {
2712 ctxt->dst.val = ctxt->src.val;
2713 return X86EMUL_CONTINUE;
2714 }
2715
2716 static int em_cr_write(struct x86_emulate_ctxt *ctxt)
2717 {
2718 if (ctxt->ops->set_cr(ctxt, ctxt->modrm_reg, ctxt->src.val))
2719 return emulate_gp(ctxt, 0);
2720
2721 /* Disable writeback. */
2722 ctxt->dst.type = OP_NONE;
2723 return X86EMUL_CONTINUE;
2724 }
2725
2726 static int em_dr_write(struct x86_emulate_ctxt *ctxt)
2727 {
2728 unsigned long val;
2729
2730 if (ctxt->mode == X86EMUL_MODE_PROT64)
2731 val = ctxt->src.val & ~0ULL;
2732 else
2733 val = ctxt->src.val & ~0U;
2734
2735 /* #UD condition is already handled. */
2736 if (ctxt->ops->set_dr(ctxt, ctxt->modrm_reg, val) < 0)
2737 return emulate_gp(ctxt, 0);
2738
2739 /* Disable writeback. */
2740 ctxt->dst.type = OP_NONE;
2741 return X86EMUL_CONTINUE;
2742 }
2743
2744 static int em_wrmsr(struct x86_emulate_ctxt *ctxt)
2745 {
2746 u64 msr_data;
2747
2748 msr_data = (u32)ctxt->regs[VCPU_REGS_RAX]
2749 | ((u64)ctxt->regs[VCPU_REGS_RDX] << 32);
2750 if (ctxt->ops->set_msr(ctxt, ctxt->regs[VCPU_REGS_RCX], msr_data))
2751 return emulate_gp(ctxt, 0);
2752
2753 return X86EMUL_CONTINUE;
2754 }
2755
2756 static int em_rdmsr(struct x86_emulate_ctxt *ctxt)
2757 {
2758 u64 msr_data;
2759
2760 if (ctxt->ops->get_msr(ctxt, ctxt->regs[VCPU_REGS_RCX], &msr_data))
2761 return emulate_gp(ctxt, 0);
2762
2763 ctxt->regs[VCPU_REGS_RAX] = (u32)msr_data;
2764 ctxt->regs[VCPU_REGS_RDX] = msr_data >> 32;
2765 return X86EMUL_CONTINUE;
2766 }
2767
2768 static int em_mov_rm_sreg(struct x86_emulate_ctxt *ctxt)
2769 {
2770 if (ctxt->modrm_reg > VCPU_SREG_GS)
2771 return emulate_ud(ctxt);
2772
2773 ctxt->dst.val = get_segment_selector(ctxt, ctxt->modrm_reg);
2774 return X86EMUL_CONTINUE;
2775 }
2776
2777 static int em_mov_sreg_rm(struct x86_emulate_ctxt *ctxt)
2778 {
2779 u16 sel = ctxt->src.val;
2780
2781 if (ctxt->modrm_reg == VCPU_SREG_CS || ctxt->modrm_reg > VCPU_SREG_GS)
2782 return emulate_ud(ctxt);
2783
2784 if (ctxt->modrm_reg == VCPU_SREG_SS)
2785 ctxt->interruptibility = KVM_X86_SHADOW_INT_MOV_SS;
2786
2787 /* Disable writeback. */
2788 ctxt->dst.type = OP_NONE;
2789 return load_segment_descriptor(ctxt, sel, ctxt->modrm_reg);
2790 }
2791
2792 static int em_movdqu(struct x86_emulate_ctxt *ctxt)
2793 {
2794 memcpy(&ctxt->dst.vec_val, &ctxt->src.vec_val, ctxt->op_bytes);
2795 return X86EMUL_CONTINUE;
2796 }
2797
2798 static int em_invlpg(struct x86_emulate_ctxt *ctxt)
2799 {
2800 int rc;
2801 ulong linear;
2802
2803 rc = linearize(ctxt, ctxt->src.addr.mem, 1, false, &linear);
2804 if (rc == X86EMUL_CONTINUE)
2805 ctxt->ops->invlpg(ctxt, linear);
2806 /* Disable writeback. */
2807 ctxt->dst.type = OP_NONE;
2808 return X86EMUL_CONTINUE;
2809 }
2810
2811 static int em_clts(struct x86_emulate_ctxt *ctxt)
2812 {
2813 ulong cr0;
2814
2815 cr0 = ctxt->ops->get_cr(ctxt, 0);
2816 cr0 &= ~X86_CR0_TS;
2817 ctxt->ops->set_cr(ctxt, 0, cr0);
2818 return X86EMUL_CONTINUE;
2819 }
2820
2821 static int em_vmcall(struct x86_emulate_ctxt *ctxt)
2822 {
2823 int rc;
2824
2825 if (ctxt->modrm_mod != 3 || ctxt->modrm_rm != 1)
2826 return X86EMUL_UNHANDLEABLE;
2827
2828 rc = ctxt->ops->fix_hypercall(ctxt);
2829 if (rc != X86EMUL_CONTINUE)
2830 return rc;
2831
2832 /* Let the processor re-execute the fixed hypercall */
2833 ctxt->_eip = ctxt->eip;
2834 /* Disable writeback. */
2835 ctxt->dst.type = OP_NONE;
2836 return X86EMUL_CONTINUE;
2837 }
2838
2839 static int em_lgdt(struct x86_emulate_ctxt *ctxt)
2840 {
2841 struct desc_ptr desc_ptr;
2842 int rc;
2843
2844 rc = read_descriptor(ctxt, ctxt->src.addr.mem,
2845 &desc_ptr.size, &desc_ptr.address,
2846 ctxt->op_bytes);
2847 if (rc != X86EMUL_CONTINUE)
2848 return rc;
2849 ctxt->ops->set_gdt(ctxt, &desc_ptr);
2850 /* Disable writeback. */
2851 ctxt->dst.type = OP_NONE;
2852 return X86EMUL_CONTINUE;
2853 }
2854
2855 static int em_vmmcall(struct x86_emulate_ctxt *ctxt)
2856 {
2857 int rc;
2858
2859 rc = ctxt->ops->fix_hypercall(ctxt);
2860
2861 /* Disable writeback. */
2862 ctxt->dst.type = OP_NONE;
2863 return rc;
2864 }
2865
2866 static int em_lidt(struct x86_emulate_ctxt *ctxt)
2867 {
2868 struct desc_ptr desc_ptr;
2869 int rc;
2870
2871 rc = read_descriptor(ctxt, ctxt->src.addr.mem,
2872 &desc_ptr.size, &desc_ptr.address,
2873 ctxt->op_bytes);
2874 if (rc != X86EMUL_CONTINUE)
2875 return rc;
2876 ctxt->ops->set_idt(ctxt, &desc_ptr);
2877 /* Disable writeback. */
2878 ctxt->dst.type = OP_NONE;
2879 return X86EMUL_CONTINUE;
2880 }
2881
2882 static int em_smsw(struct x86_emulate_ctxt *ctxt)
2883 {
2884 ctxt->dst.bytes = 2;
2885 ctxt->dst.val = ctxt->ops->get_cr(ctxt, 0);
2886 return X86EMUL_CONTINUE;
2887 }
2888
2889 static int em_lmsw(struct x86_emulate_ctxt *ctxt)
2890 {
2891 ctxt->ops->set_cr(ctxt, 0, (ctxt->ops->get_cr(ctxt, 0) & ~0x0eul)
2892 | (ctxt->src.val & 0x0f));
2893 ctxt->dst.type = OP_NONE;
2894 return X86EMUL_CONTINUE;
2895 }
2896
2897 static int em_loop(struct x86_emulate_ctxt *ctxt)
2898 {
2899 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1);
2900 if ((address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) != 0) &&
2901 (ctxt->b == 0xe2 || test_cc(ctxt->b ^ 0x5, ctxt->eflags)))
2902 jmp_rel(ctxt, ctxt->src.val);
2903
2904 return X86EMUL_CONTINUE;
2905 }
2906
2907 static int em_jcxz(struct x86_emulate_ctxt *ctxt)
2908 {
2909 if (address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) == 0)
2910 jmp_rel(ctxt, ctxt->src.val);
2911
2912 return X86EMUL_CONTINUE;
2913 }
2914
2915 static int em_in(struct x86_emulate_ctxt *ctxt)
2916 {
2917 if (!pio_in_emulated(ctxt, ctxt->dst.bytes, ctxt->src.val,
2918 &ctxt->dst.val))
2919 return X86EMUL_IO_NEEDED;
2920
2921 return X86EMUL_CONTINUE;
2922 }
2923
2924 static int em_out(struct x86_emulate_ctxt *ctxt)
2925 {
2926 ctxt->ops->pio_out_emulated(ctxt, ctxt->src.bytes, ctxt->dst.val,
2927 &ctxt->src.val, 1);
2928 /* Disable writeback. */
2929 ctxt->dst.type = OP_NONE;
2930 return X86EMUL_CONTINUE;
2931 }
2932
2933 static int em_cli(struct x86_emulate_ctxt *ctxt)
2934 {
2935 if (emulator_bad_iopl(ctxt))
2936 return emulate_gp(ctxt, 0);
2937
2938 ctxt->eflags &= ~X86_EFLAGS_IF;
2939 return X86EMUL_CONTINUE;
2940 }
2941
2942 static int em_sti(struct x86_emulate_ctxt *ctxt)
2943 {
2944 if (emulator_bad_iopl(ctxt))
2945 return emulate_gp(ctxt, 0);
2946
2947 ctxt->interruptibility = KVM_X86_SHADOW_INT_STI;
2948 ctxt->eflags |= X86_EFLAGS_IF;
2949 return X86EMUL_CONTINUE;
2950 }
2951
2952 static int em_bt(struct x86_emulate_ctxt *ctxt)
2953 {
2954 /* Disable writeback. */
2955 ctxt->dst.type = OP_NONE;
2956 /* only subword offset */
2957 ctxt->src.val &= (ctxt->dst.bytes << 3) - 1;
2958
2959 emulate_2op_SrcV_nobyte(ctxt, "bt");
2960 return X86EMUL_CONTINUE;
2961 }
2962
2963 static int em_bts(struct x86_emulate_ctxt *ctxt)
2964 {
2965 emulate_2op_SrcV_nobyte(ctxt, "bts");
2966 return X86EMUL_CONTINUE;
2967 }
2968
2969 static int em_btr(struct x86_emulate_ctxt *ctxt)
2970 {
2971 emulate_2op_SrcV_nobyte(ctxt, "btr");
2972 return X86EMUL_CONTINUE;
2973 }
2974
2975 static int em_btc(struct x86_emulate_ctxt *ctxt)
2976 {
2977 emulate_2op_SrcV_nobyte(ctxt, "btc");
2978 return X86EMUL_CONTINUE;
2979 }
2980
2981 static int em_bsf(struct x86_emulate_ctxt *ctxt)
2982 {
2983 u8 zf;
2984
2985 __asm__ ("bsf %2, %0; setz %1"
2986 : "=r"(ctxt->dst.val), "=q"(zf)
2987 : "r"(ctxt->src.val));
2988
2989 ctxt->eflags &= ~X86_EFLAGS_ZF;
2990 if (zf) {
2991 ctxt->eflags |= X86_EFLAGS_ZF;
2992 /* Disable writeback. */
2993 ctxt->dst.type = OP_NONE;
2994 }
2995 return X86EMUL_CONTINUE;
2996 }
2997
2998 static int em_bsr(struct x86_emulate_ctxt *ctxt)
2999 {
3000 u8 zf;
3001
3002 __asm__ ("bsr %2, %0; setz %1"
3003 : "=r"(ctxt->dst.val), "=q"(zf)
3004 : "r"(ctxt->src.val));
3005
3006 ctxt->eflags &= ~X86_EFLAGS_ZF;
3007 if (zf) {
3008 ctxt->eflags |= X86_EFLAGS_ZF;
3009 /* Disable writeback. */
3010 ctxt->dst.type = OP_NONE;
3011 }
3012 return X86EMUL_CONTINUE;
3013 }
3014
3015 static bool valid_cr(int nr)
3016 {
3017 switch (nr) {
3018 case 0:
3019 case 2 ... 4:
3020 case 8:
3021 return true;
3022 default:
3023 return false;
3024 }
3025 }
3026
3027 static int check_cr_read(struct x86_emulate_ctxt *ctxt)
3028 {
3029 if (!valid_cr(ctxt->modrm_reg))
3030 return emulate_ud(ctxt);
3031
3032 return X86EMUL_CONTINUE;
3033 }
3034
3035 static int check_cr_write(struct x86_emulate_ctxt *ctxt)
3036 {
3037 u64 new_val = ctxt->src.val64;
3038 int cr = ctxt->modrm_reg;
3039 u64 efer = 0;
3040
3041 static u64 cr_reserved_bits[] = {
3042 0xffffffff00000000ULL,
3043 0, 0, 0, /* CR3 checked later */
3044 CR4_RESERVED_BITS,
3045 0, 0, 0,
3046 CR8_RESERVED_BITS,
3047 };
3048
3049 if (!valid_cr(cr))
3050 return emulate_ud(ctxt);
3051
3052 if (new_val & cr_reserved_bits[cr])
3053 return emulate_gp(ctxt, 0);
3054
3055 switch (cr) {
3056 case 0: {
3057 u64 cr4;
3058 if (((new_val & X86_CR0_PG) && !(new_val & X86_CR0_PE)) ||
3059 ((new_val & X86_CR0_NW) && !(new_val & X86_CR0_CD)))
3060 return emulate_gp(ctxt, 0);
3061
3062 cr4 = ctxt->ops->get_cr(ctxt, 4);
3063 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3064
3065 if ((new_val & X86_CR0_PG) && (efer & EFER_LME) &&
3066 !(cr4 & X86_CR4_PAE))
3067 return emulate_gp(ctxt, 0);
3068
3069 break;
3070 }
3071 case 3: {
3072 u64 rsvd = 0;
3073
3074 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3075 if (efer & EFER_LMA)
3076 rsvd = CR3_L_MODE_RESERVED_BITS;
3077 else if (ctxt->ops->get_cr(ctxt, 4) & X86_CR4_PAE)
3078 rsvd = CR3_PAE_RESERVED_BITS;
3079 else if (ctxt->ops->get_cr(ctxt, 0) & X86_CR0_PG)
3080 rsvd = CR3_NONPAE_RESERVED_BITS;
3081
3082 if (new_val & rsvd)
3083 return emulate_gp(ctxt, 0);
3084
3085 break;
3086 }
3087 case 4: {
3088 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3089
3090 if ((efer & EFER_LMA) && !(new_val & X86_CR4_PAE))
3091 return emulate_gp(ctxt, 0);
3092
3093 break;
3094 }
3095 }
3096
3097 return X86EMUL_CONTINUE;
3098 }
3099
3100 static int check_dr7_gd(struct x86_emulate_ctxt *ctxt)
3101 {
3102 unsigned long dr7;
3103
3104 ctxt->ops->get_dr(ctxt, 7, &dr7);
3105
3106 /* Check if DR7.Global_Enable is set */
3107 return dr7 & (1 << 13);
3108 }
3109
3110 static int check_dr_read(struct x86_emulate_ctxt *ctxt)
3111 {
3112 int dr = ctxt->modrm_reg;
3113 u64 cr4;
3114
3115 if (dr > 7)
3116 return emulate_ud(ctxt);
3117
3118 cr4 = ctxt->ops->get_cr(ctxt, 4);
3119 if ((cr4 & X86_CR4_DE) && (dr == 4 || dr == 5))
3120 return emulate_ud(ctxt);
3121
3122 if (check_dr7_gd(ctxt))
3123 return emulate_db(ctxt);
3124
3125 return X86EMUL_CONTINUE;
3126 }
3127
3128 static int check_dr_write(struct x86_emulate_ctxt *ctxt)
3129 {
3130 u64 new_val = ctxt->src.val64;
3131 int dr = ctxt->modrm_reg;
3132
3133 if ((dr == 6 || dr == 7) && (new_val & 0xffffffff00000000ULL))
3134 return emulate_gp(ctxt, 0);
3135
3136 return check_dr_read(ctxt);
3137 }
3138
3139 static int check_svme(struct x86_emulate_ctxt *ctxt)
3140 {
3141 u64 efer;
3142
3143 ctxt->ops->get_msr(ctxt, MSR_EFER, &efer);
3144
3145 if (!(efer & EFER_SVME))
3146 return emulate_ud(ctxt);
3147
3148 return X86EMUL_CONTINUE;
3149 }
3150
3151 static int check_svme_pa(struct x86_emulate_ctxt *ctxt)
3152 {
3153 u64 rax = ctxt->regs[VCPU_REGS_RAX];
3154
3155 /* Valid physical address? */
3156 if (rax & 0xffff000000000000ULL)
3157 return emulate_gp(ctxt, 0);
3158
3159 return check_svme(ctxt);
3160 }
3161
3162 static int check_rdtsc(struct x86_emulate_ctxt *ctxt)
3163 {
3164 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3165
3166 if (cr4 & X86_CR4_TSD && ctxt->ops->cpl(ctxt))
3167 return emulate_ud(ctxt);
3168
3169 return X86EMUL_CONTINUE;
3170 }
3171
3172 static int check_rdpmc(struct x86_emulate_ctxt *ctxt)
3173 {
3174 u64 cr4 = ctxt->ops->get_cr(ctxt, 4);
3175 u64 rcx = ctxt->regs[VCPU_REGS_RCX];
3176
3177 if ((!(cr4 & X86_CR4_PCE) && ctxt->ops->cpl(ctxt)) ||
3178 (rcx > 3))
3179 return emulate_gp(ctxt, 0);
3180
3181 return X86EMUL_CONTINUE;
3182 }
3183
3184 static int check_perm_in(struct x86_emulate_ctxt *ctxt)
3185 {
3186 ctxt->dst.bytes = min(ctxt->dst.bytes, 4u);
3187 if (!emulator_io_permited(ctxt, ctxt->src.val, ctxt->dst.bytes))
3188 return emulate_gp(ctxt, 0);
3189
3190 return X86EMUL_CONTINUE;
3191 }
3192
3193 static int check_perm_out(struct x86_emulate_ctxt *ctxt)
3194 {
3195 ctxt->src.bytes = min(ctxt->src.bytes, 4u);
3196 if (!emulator_io_permited(ctxt, ctxt->dst.val, ctxt->src.bytes))
3197 return emulate_gp(ctxt, 0);
3198
3199 return X86EMUL_CONTINUE;
3200 }
3201
3202 #define D(_y) { .flags = (_y) }
3203 #define DI(_y, _i) { .flags = (_y), .intercept = x86_intercept_##_i }
3204 #define DIP(_y, _i, _p) { .flags = (_y), .intercept = x86_intercept_##_i, \
3205 .check_perm = (_p) }
3206 #define N D(0)
3207 #define EXT(_f, _e) { .flags = ((_f) | RMExt), .u.group = (_e) }
3208 #define G(_f, _g) { .flags = ((_f) | Group), .u.group = (_g) }
3209 #define GD(_f, _g) { .flags = ((_f) | GroupDual), .u.gdual = (_g) }
3210 #define I(_f, _e) { .flags = (_f), .u.execute = (_e) }
3211 #define II(_f, _e, _i) \
3212 { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i }
3213 #define IIP(_f, _e, _i, _p) \
3214 { .flags = (_f), .u.execute = (_e), .intercept = x86_intercept_##_i, \
3215 .check_perm = (_p) }
3216 #define GP(_f, _g) { .flags = ((_f) | Prefix), .u.gprefix = (_g) }
3217
3218 #define D2bv(_f) D((_f) | ByteOp), D(_f)
3219 #define D2bvIP(_f, _i, _p) DIP((_f) | ByteOp, _i, _p), DIP(_f, _i, _p)
3220 #define I2bv(_f, _e) I((_f) | ByteOp, _e), I(_f, _e)
3221 #define I2bvIP(_f, _e, _i, _p) \
3222 IIP((_f) | ByteOp, _e, _i, _p), IIP(_f, _e, _i, _p)
3223
3224 #define I6ALU(_f, _e) I2bv((_f) | DstMem | SrcReg | ModRM, _e), \
3225 I2bv(((_f) | DstReg | SrcMem | ModRM) & ~Lock, _e), \
3226 I2bv(((_f) & ~Lock) | DstAcc | SrcImm, _e)
3227
3228 static struct opcode group7_rm1[] = {
3229 DI(SrcNone | ModRM | Priv, monitor),
3230 DI(SrcNone | ModRM | Priv, mwait),
3231 N, N, N, N, N, N,
3232 };
3233
3234 static struct opcode group7_rm3[] = {
3235 DIP(SrcNone | ModRM | Prot | Priv, vmrun, check_svme_pa),
3236 II(SrcNone | ModRM | Prot | VendorSpecific, em_vmmcall, vmmcall),
3237 DIP(SrcNone | ModRM | Prot | Priv, vmload, check_svme_pa),
3238 DIP(SrcNone | ModRM | Prot | Priv, vmsave, check_svme_pa),
3239 DIP(SrcNone | ModRM | Prot | Priv, stgi, check_svme),
3240 DIP(SrcNone | ModRM | Prot | Priv, clgi, check_svme),
3241 DIP(SrcNone | ModRM | Prot | Priv, skinit, check_svme),
3242 DIP(SrcNone | ModRM | Prot | Priv, invlpga, check_svme),
3243 };
3244
3245 static struct opcode group7_rm7[] = {
3246 N,
3247 DIP(SrcNone | ModRM, rdtscp, check_rdtsc),
3248 N, N, N, N, N, N,
3249 };
3250
3251 static struct opcode group1[] = {
3252 I(Lock, em_add),
3253 I(Lock | PageTable, em_or),
3254 I(Lock, em_adc),
3255 I(Lock, em_sbb),
3256 I(Lock | PageTable, em_and),
3257 I(Lock, em_sub),
3258 I(Lock, em_xor),
3259 I(0, em_cmp),
3260 };
3261
3262 static struct opcode group1A[] = {
3263 I(DstMem | SrcNone | ModRM | Mov | Stack, em_pop), N, N, N, N, N, N, N,
3264 };
3265
3266 static struct opcode group3[] = {
3267 I(DstMem | SrcImm | ModRM, em_test),
3268 I(DstMem | SrcImm | ModRM, em_test),
3269 I(DstMem | SrcNone | ModRM | Lock, em_not),
3270 I(DstMem | SrcNone | ModRM | Lock, em_neg),
3271 I(SrcMem | ModRM, em_mul_ex),
3272 I(SrcMem | ModRM, em_imul_ex),
3273 I(SrcMem | ModRM, em_div_ex),
3274 I(SrcMem | ModRM, em_idiv_ex),
3275 };
3276
3277 static struct opcode group4[] = {
3278 I(ByteOp | DstMem | SrcNone | ModRM | Lock, em_grp45),
3279 I(ByteOp | DstMem | SrcNone | ModRM | Lock, em_grp45),
3280 N, N, N, N, N, N,
3281 };
3282
3283 static struct opcode group5[] = {
3284 I(DstMem | SrcNone | ModRM | Lock, em_grp45),
3285 I(DstMem | SrcNone | ModRM | Lock, em_grp45),
3286 I(SrcMem | ModRM | Stack, em_grp45),
3287 I(SrcMemFAddr | ModRM | ImplicitOps | Stack, em_call_far),
3288 I(SrcMem | ModRM | Stack, em_grp45),
3289 I(SrcMemFAddr | ModRM | ImplicitOps, em_grp45),
3290 I(SrcMem | ModRM | Stack, em_grp45), N,
3291 };
3292
3293 static struct opcode group6[] = {
3294 DI(ModRM | Prot, sldt),
3295 DI(ModRM | Prot, str),
3296 DI(ModRM | Prot | Priv, lldt),
3297 DI(ModRM | Prot | Priv, ltr),
3298 N, N, N, N,
3299 };
3300
3301 static struct group_dual group7 = { {
3302 DI(ModRM | Mov | DstMem | Priv, sgdt),
3303 DI(ModRM | Mov | DstMem | Priv, sidt),
3304 II(ModRM | SrcMem | Priv, em_lgdt, lgdt),
3305 II(ModRM | SrcMem | Priv, em_lidt, lidt),
3306 II(SrcNone | ModRM | DstMem | Mov, em_smsw, smsw), N,
3307 II(SrcMem16 | ModRM | Mov | Priv, em_lmsw, lmsw),
3308 II(SrcMem | ModRM | ByteOp | Priv | NoAccess, em_invlpg, invlpg),
3309 }, {
3310 I(SrcNone | ModRM | Priv | VendorSpecific, em_vmcall),
3311 EXT(0, group7_rm1),
3312 N, EXT(0, group7_rm3),
3313 II(SrcNone | ModRM | DstMem | Mov, em_smsw, smsw), N,
3314 II(SrcMem16 | ModRM | Mov | Priv, em_lmsw, lmsw), EXT(0, group7_rm7),
3315 } };
3316
3317 static struct opcode group8[] = {
3318 N, N, N, N,
3319 I(DstMem | SrcImmByte | ModRM, em_bt),
3320 I(DstMem | SrcImmByte | ModRM | Lock | PageTable, em_bts),
3321 I(DstMem | SrcImmByte | ModRM | Lock, em_btr),
3322 I(DstMem | SrcImmByte | ModRM | Lock | PageTable, em_btc),
3323 };
3324
3325 static struct group_dual group9 = { {
3326 N, I(DstMem64 | ModRM | Lock | PageTable, em_cmpxchg8b), N, N, N, N, N, N,
3327 }, {
3328 N, N, N, N, N, N, N, N,
3329 } };
3330
3331 static struct opcode group11[] = {
3332 I(DstMem | SrcImm | ModRM | Mov | PageTable, em_mov),
3333 X7(D(Undefined)),
3334 };
3335
3336 static struct gprefix pfx_0f_6f_0f_7f = {
3337 N, N, N, I(Sse, em_movdqu),
3338 };
3339
3340 static struct opcode opcode_table[256] = {
3341 /* 0x00 - 0x07 */
3342 I6ALU(Lock, em_add),
3343 I(ImplicitOps | Stack | No64 | Src2ES, em_push_sreg),
3344 I(ImplicitOps | Stack | No64 | Src2ES, em_pop_sreg),
3345 /* 0x08 - 0x0F */
3346 I6ALU(Lock | PageTable, em_or),
3347 I(ImplicitOps | Stack | No64 | Src2CS, em_push_sreg),
3348 N,
3349 /* 0x10 - 0x17 */
3350 I6ALU(Lock, em_adc),
3351 I(ImplicitOps | Stack | No64 | Src2SS, em_push_sreg),
3352 I(ImplicitOps | Stack | No64 | Src2SS, em_pop_sreg),
3353 /* 0x18 - 0x1F */
3354 I6ALU(Lock, em_sbb),
3355 I(ImplicitOps | Stack | No64 | Src2DS, em_push_sreg),
3356 I(ImplicitOps | Stack | No64 | Src2DS, em_pop_sreg),
3357 /* 0x20 - 0x27 */
3358 I6ALU(Lock | PageTable, em_and), N, N,
3359 /* 0x28 - 0x2F */
3360 I6ALU(Lock, em_sub), N, I(ByteOp | DstAcc | No64, em_das),
3361 /* 0x30 - 0x37 */
3362 I6ALU(Lock, em_xor), N, N,
3363 /* 0x38 - 0x3F */
3364 I6ALU(0, em_cmp), N, N,
3365 /* 0x40 - 0x4F */
3366 X16(D(DstReg)),
3367 /* 0x50 - 0x57 */
3368 X8(I(SrcReg | Stack, em_push)),
3369 /* 0x58 - 0x5F */
3370 X8(I(DstReg | Stack, em_pop)),
3371 /* 0x60 - 0x67 */
3372 I(ImplicitOps | Stack | No64, em_pusha),
3373 I(ImplicitOps | Stack | No64, em_popa),
3374 N, D(DstReg | SrcMem32 | ModRM | Mov) /* movsxd (x86/64) */ ,
3375 N, N, N, N,
3376 /* 0x68 - 0x6F */
3377 I(SrcImm | Mov | Stack, em_push),
3378 I(DstReg | SrcMem | ModRM | Src2Imm, em_imul_3op),
3379 I(SrcImmByte | Mov | Stack, em_push),
3380 I(DstReg | SrcMem | ModRM | Src2ImmByte, em_imul_3op),
3381 I2bvIP(DstDI | SrcDX | Mov | String, em_in, ins, check_perm_in), /* insb, insw/insd */
3382 I2bvIP(SrcSI | DstDX | String, em_out, outs, check_perm_out), /* outsb, outsw/outsd */
3383 /* 0x70 - 0x7F */
3384 X16(D(SrcImmByte)),
3385 /* 0x80 - 0x87 */
3386 G(ByteOp | DstMem | SrcImm | ModRM | Group, group1),
3387 G(DstMem | SrcImm | ModRM | Group, group1),
3388 G(ByteOp | DstMem | SrcImm | ModRM | No64 | Group, group1),
3389 G(DstMem | SrcImmByte | ModRM | Group, group1),
3390 I2bv(DstMem | SrcReg | ModRM, em_test),
3391 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_xchg),
3392 /* 0x88 - 0x8F */
3393 I2bv(DstMem | SrcReg | ModRM | Mov | PageTable, em_mov),
3394 I2bv(DstReg | SrcMem | ModRM | Mov, em_mov),
3395 I(DstMem | SrcNone | ModRM | Mov | PageTable, em_mov_rm_sreg),
3396 D(ModRM | SrcMem | NoAccess | DstReg),
3397 I(ImplicitOps | SrcMem16 | ModRM, em_mov_sreg_rm),
3398 G(0, group1A),
3399 /* 0x90 - 0x97 */
3400 DI(SrcAcc | DstReg, pause), X7(D(SrcAcc | DstReg)),
3401 /* 0x98 - 0x9F */
3402 D(DstAcc | SrcNone), I(ImplicitOps | SrcAcc, em_cwd),
3403 I(SrcImmFAddr | No64, em_call_far), N,
3404 II(ImplicitOps | Stack, em_pushf, pushf),
3405 II(ImplicitOps | Stack, em_popf, popf), N, N,
3406 /* 0xA0 - 0xA7 */
3407 I2bv(DstAcc | SrcMem | Mov | MemAbs, em_mov),
3408 I2bv(DstMem | SrcAcc | Mov | MemAbs | PageTable, em_mov),
3409 I2bv(SrcSI | DstDI | Mov | String, em_mov),
3410 I2bv(SrcSI | DstDI | String, em_cmp),
3411 /* 0xA8 - 0xAF */
3412 I2bv(DstAcc | SrcImm, em_test),
3413 I2bv(SrcAcc | DstDI | Mov | String, em_mov),
3414 I2bv(SrcSI | DstAcc | Mov | String, em_mov),
3415 I2bv(SrcAcc | DstDI | String, em_cmp),
3416 /* 0xB0 - 0xB7 */
3417 X8(I(ByteOp | DstReg | SrcImm | Mov, em_mov)),
3418 /* 0xB8 - 0xBF */
3419 X8(I(DstReg | SrcImm | Mov, em_mov)),
3420 /* 0xC0 - 0xC7 */
3421 D2bv(DstMem | SrcImmByte | ModRM),
3422 I(ImplicitOps | Stack | SrcImmU16, em_ret_near_imm),
3423 I(ImplicitOps | Stack, em_ret),
3424 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2ES, em_lseg),
3425 I(DstReg | SrcMemFAddr | ModRM | No64 | Src2DS, em_lseg),
3426 G(ByteOp, group11), G(0, group11),
3427 /* 0xC8 - 0xCF */
3428 N, N, N, I(ImplicitOps | Stack, em_ret_far),
3429 D(ImplicitOps), DI(SrcImmByte, intn),
3430 D(ImplicitOps | No64), II(ImplicitOps, em_iret, iret),
3431 /* 0xD0 - 0xD7 */
3432 D2bv(DstMem | SrcOne | ModRM), D2bv(DstMem | ModRM),
3433 N, N, N, N,
3434 /* 0xD8 - 0xDF */
3435 N, N, N, N, N, N, N, N,
3436 /* 0xE0 - 0xE7 */
3437 X3(I(SrcImmByte, em_loop)),
3438 I(SrcImmByte, em_jcxz),
3439 I2bvIP(SrcImmUByte | DstAcc, em_in, in, check_perm_in),
3440 I2bvIP(SrcAcc | DstImmUByte, em_out, out, check_perm_out),
3441 /* 0xE8 - 0xEF */
3442 I(SrcImm | Stack, em_call), D(SrcImm | ImplicitOps),
3443 I(SrcImmFAddr | No64, em_jmp_far), D(SrcImmByte | ImplicitOps),
3444 I2bvIP(SrcDX | DstAcc, em_in, in, check_perm_in),
3445 I2bvIP(SrcAcc | DstDX, em_out, out, check_perm_out),
3446 /* 0xF0 - 0xF7 */
3447 N, DI(ImplicitOps, icebp), N, N,
3448 DI(ImplicitOps | Priv, hlt), D(ImplicitOps),
3449 G(ByteOp, group3), G(0, group3),
3450 /* 0xF8 - 0xFF */
3451 D(ImplicitOps), D(ImplicitOps),
3452 I(ImplicitOps, em_cli), I(ImplicitOps, em_sti),
3453 D(ImplicitOps), D(ImplicitOps), G(0, group4), G(0, group5),
3454 };
3455
3456 static struct opcode twobyte_table[256] = {
3457 /* 0x00 - 0x0F */
3458 G(0, group6), GD(0, &group7), N, N,
3459 N, I(ImplicitOps | VendorSpecific, em_syscall),
3460 II(ImplicitOps | Priv, em_clts, clts), N,
3461 DI(ImplicitOps | Priv, invd), DI(ImplicitOps | Priv, wbinvd), N, N,
3462 N, D(ImplicitOps | ModRM), N, N,
3463 /* 0x10 - 0x1F */
3464 N, N, N, N, N, N, N, N, D(ImplicitOps | ModRM), N, N, N, N, N, N, N,
3465 /* 0x20 - 0x2F */
3466 DIP(ModRM | DstMem | Priv | Op3264, cr_read, check_cr_read),
3467 DIP(ModRM | DstMem | Priv | Op3264, dr_read, check_dr_read),
3468 IIP(ModRM | SrcMem | Priv | Op3264, em_cr_write, cr_write, check_cr_write),
3469 IIP(ModRM | SrcMem | Priv | Op3264, em_dr_write, dr_write, check_dr_write),
3470 N, N, N, N,
3471 N, N, N, N, N, N, N, N,
3472 /* 0x30 - 0x3F */
3473 II(ImplicitOps | Priv, em_wrmsr, wrmsr),
3474 IIP(ImplicitOps, em_rdtsc, rdtsc, check_rdtsc),
3475 II(ImplicitOps | Priv, em_rdmsr, rdmsr),
3476 IIP(ImplicitOps, em_rdpmc, rdpmc, check_rdpmc),
3477 I(ImplicitOps | VendorSpecific, em_sysenter),
3478 I(ImplicitOps | Priv | VendorSpecific, em_sysexit),
3479 N, N,
3480 N, N, N, N, N, N, N, N,
3481 /* 0x40 - 0x4F */
3482 X16(D(DstReg | SrcMem | ModRM | Mov)),
3483 /* 0x50 - 0x5F */
3484 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3485 /* 0x60 - 0x6F */
3486 N, N, N, N,
3487 N, N, N, N,
3488 N, N, N, N,
3489 N, N, N, GP(SrcMem | DstReg | ModRM | Mov, &pfx_0f_6f_0f_7f),
3490 /* 0x70 - 0x7F */
3491 N, N, N, N,
3492 N, N, N, N,
3493 N, N, N, N,
3494 N, N, N, GP(SrcReg | DstMem | ModRM | Mov, &pfx_0f_6f_0f_7f),
3495 /* 0x80 - 0x8F */
3496 X16(D(SrcImm)),
3497 /* 0x90 - 0x9F */
3498 X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
3499 /* 0xA0 - 0xA7 */
3500 I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
3501 DI(ImplicitOps, cpuid), I(DstMem | SrcReg | ModRM | BitOp, em_bt),
3502 D(DstMem | SrcReg | Src2ImmByte | ModRM),
3503 D(DstMem | SrcReg | Src2CL | ModRM), N, N,
3504 /* 0xA8 - 0xAF */
3505 I(Stack | Src2GS, em_push_sreg), I(Stack | Src2GS, em_pop_sreg),
3506 DI(ImplicitOps, rsm),
3507 I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_bts),
3508 D(DstMem | SrcReg | Src2ImmByte | ModRM),
3509 D(DstMem | SrcReg | Src2CL | ModRM),
3510 D(ModRM), I(DstReg | SrcMem | ModRM, em_imul),
3511 /* 0xB0 - 0xB7 */
3512 I2bv(DstMem | SrcReg | ModRM | Lock | PageTable, em_cmpxchg),
3513 I(DstReg | SrcMemFAddr | ModRM | Src2SS, em_lseg),
3514 I(DstMem | SrcReg | ModRM | BitOp | Lock, em_btr),
3515 I(DstReg | SrcMemFAddr | ModRM | Src2FS, em_lseg),
3516 I(DstReg | SrcMemFAddr | ModRM | Src2GS, em_lseg),
3517 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
3518 /* 0xB8 - 0xBF */
3519 N, N,
3520 G(BitOp, group8),
3521 I(DstMem | SrcReg | ModRM | BitOp | Lock | PageTable, em_btc),
3522 I(DstReg | SrcMem | ModRM, em_bsf), I(DstReg | SrcMem | ModRM, em_bsr),
3523 D(ByteOp | DstReg | SrcMem | ModRM | Mov), D(DstReg | SrcMem16 | ModRM | Mov),
3524 /* 0xC0 - 0xCF */
3525 D2bv(DstMem | SrcReg | ModRM | Lock),
3526 N, D(DstMem | SrcReg | ModRM | Mov),
3527 N, N, N, GD(0, &group9),
3528 N, N, N, N, N, N, N, N,
3529 /* 0xD0 - 0xDF */
3530 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3531 /* 0xE0 - 0xEF */
3532 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N,
3533 /* 0xF0 - 0xFF */
3534 N, N, N, N, N, N, N, N, N, N, N, N, N, N, N, N
3535 };
3536
3537 #undef D
3538 #undef N
3539 #undef G
3540 #undef GD
3541 #undef I
3542 #undef GP
3543 #undef EXT
3544
3545 #undef D2bv
3546 #undef D2bvIP
3547 #undef I2bv
3548 #undef I2bvIP
3549 #undef I6ALU
3550
3551 static unsigned imm_size(struct x86_emulate_ctxt *ctxt)
3552 {
3553 unsigned size;
3554
3555 size = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3556 if (size == 8)
3557 size = 4;
3558 return size;
3559 }
3560
3561 static int decode_imm(struct x86_emulate_ctxt *ctxt, struct operand *op,
3562 unsigned size, bool sign_extension)
3563 {
3564 int rc = X86EMUL_CONTINUE;
3565
3566 op->type = OP_IMM;
3567 op->bytes = size;
3568 op->addr.mem.ea = ctxt->_eip;
3569 /* NB. Immediates are sign-extended as necessary. */
3570 switch (op->bytes) {
3571 case 1:
3572 op->val = insn_fetch(s8, ctxt);
3573 break;
3574 case 2:
3575 op->val = insn_fetch(s16, ctxt);
3576 break;
3577 case 4:
3578 op->val = insn_fetch(s32, ctxt);
3579 break;
3580 }
3581 if (!sign_extension) {
3582 switch (op->bytes) {
3583 case 1:
3584 op->val &= 0xff;
3585 break;
3586 case 2:
3587 op->val &= 0xffff;
3588 break;
3589 case 4:
3590 op->val &= 0xffffffff;
3591 break;
3592 }
3593 }
3594 done:
3595 return rc;
3596 }
3597
3598 static int decode_operand(struct x86_emulate_ctxt *ctxt, struct operand *op,
3599 unsigned d)
3600 {
3601 int rc = X86EMUL_CONTINUE;
3602
3603 switch (d) {
3604 case OpReg:
3605 decode_register_operand(ctxt, op,
3606 op == &ctxt->dst &&
3607 ctxt->twobyte && (ctxt->b == 0xb6 || ctxt->b == 0xb7));
3608 break;
3609 case OpImmUByte:
3610 rc = decode_imm(ctxt, op, 1, false);
3611 break;
3612 case OpMem:
3613 ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3614 mem_common:
3615 *op = ctxt->memop;
3616 ctxt->memopp = op;
3617 if ((ctxt->d & BitOp) && op == &ctxt->dst)
3618 fetch_bit_operand(ctxt);
3619 op->orig_val = op->val;
3620 break;
3621 case OpMem64:
3622 ctxt->memop.bytes = 8;
3623 goto mem_common;
3624 case OpAcc:
3625 op->type = OP_REG;
3626 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3627 op->addr.reg = &ctxt->regs[VCPU_REGS_RAX];
3628 fetch_register_operand(op);
3629 op->orig_val = op->val;
3630 break;
3631 case OpDI:
3632 op->type = OP_MEM;
3633 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3634 op->addr.mem.ea =
3635 register_address(ctxt, ctxt->regs[VCPU_REGS_RDI]);
3636 op->addr.mem.seg = VCPU_SREG_ES;
3637 op->val = 0;
3638 break;
3639 case OpDX:
3640 op->type = OP_REG;
3641 op->bytes = 2;
3642 op->addr.reg = &ctxt->regs[VCPU_REGS_RDX];
3643 fetch_register_operand(op);
3644 break;
3645 case OpCL:
3646 op->bytes = 1;
3647 op->val = ctxt->regs[VCPU_REGS_RCX] & 0xff;
3648 break;
3649 case OpImmByte:
3650 rc = decode_imm(ctxt, op, 1, true);
3651 break;
3652 case OpOne:
3653 op->bytes = 1;
3654 op->val = 1;
3655 break;
3656 case OpImm:
3657 rc = decode_imm(ctxt, op, imm_size(ctxt), true);
3658 break;
3659 case OpMem16:
3660 ctxt->memop.bytes = 2;
3661 goto mem_common;
3662 case OpMem32:
3663 ctxt->memop.bytes = 4;
3664 goto mem_common;
3665 case OpImmU16:
3666 rc = decode_imm(ctxt, op, 2, false);
3667 break;
3668 case OpImmU:
3669 rc = decode_imm(ctxt, op, imm_size(ctxt), false);
3670 break;
3671 case OpSI:
3672 op->type = OP_MEM;
3673 op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
3674 op->addr.mem.ea =
3675 register_address(ctxt, ctxt->regs[VCPU_REGS_RSI]);
3676 op->addr.mem.seg = seg_override(ctxt);
3677 op->val = 0;
3678 break;
3679 case OpImmFAddr:
3680 op->type = OP_IMM;
3681 op->addr.mem.ea = ctxt->_eip;
3682 op->bytes = ctxt->op_bytes + 2;
3683 insn_fetch_arr(op->valptr, op->bytes, ctxt);
3684 break;
3685 case OpMemFAddr:
3686 ctxt->memop.bytes = ctxt->op_bytes + 2;
3687 goto mem_common;
3688 case OpES:
3689 op->val = VCPU_SREG_ES;
3690 break;
3691 case OpCS:
3692 op->val = VCPU_SREG_CS;
3693 break;
3694 case OpSS:
3695 op->val = VCPU_SREG_SS;
3696 break;
3697 case OpDS:
3698 op->val = VCPU_SREG_DS;
3699 break;
3700 case OpFS:
3701 op->val = VCPU_SREG_FS;
3702 break;
3703 case OpGS:
3704 op->val = VCPU_SREG_GS;
3705 break;
3706 case OpImplicit:
3707 /* Special instructions do their own operand decoding. */
3708 default:
3709 op->type = OP_NONE; /* Disable writeback. */
3710 break;
3711 }
3712
3713 done:
3714 return rc;
3715 }
3716
3717 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
3718 {
3719 int rc = X86EMUL_CONTINUE;
3720 int mode = ctxt->mode;
3721 int def_op_bytes, def_ad_bytes, goffset, simd_prefix;
3722 bool op_prefix = false;
3723 struct opcode opcode;
3724
3725 ctxt->memop.type = OP_NONE;
3726 ctxt->memopp = NULL;
3727 ctxt->_eip = ctxt->eip;
3728 ctxt->fetch.start = ctxt->_eip;
3729 ctxt->fetch.end = ctxt->fetch.start + insn_len;
3730 if (insn_len > 0)
3731 memcpy(ctxt->fetch.data, insn, insn_len);
3732
3733 switch (mode) {
3734 case X86EMUL_MODE_REAL:
3735 case X86EMUL_MODE_VM86:
3736 case X86EMUL_MODE_PROT16:
3737 def_op_bytes = def_ad_bytes = 2;
3738 break;
3739 case X86EMUL_MODE_PROT32:
3740 def_op_bytes = def_ad_bytes = 4;
3741 break;
3742 #ifdef CONFIG_X86_64
3743 case X86EMUL_MODE_PROT64:
3744 def_op_bytes = 4;
3745 def_ad_bytes = 8;
3746 break;
3747 #endif
3748 default:
3749 return EMULATION_FAILED;
3750 }
3751
3752 ctxt->op_bytes = def_op_bytes;
3753 ctxt->ad_bytes = def_ad_bytes;
3754
3755 /* Legacy prefixes. */
3756 for (;;) {
3757 switch (ctxt->b = insn_fetch(u8, ctxt)) {
3758 case 0x66: /* operand-size override */
3759 op_prefix = true;
3760 /* switch between 2/4 bytes */
3761 ctxt->op_bytes = def_op_bytes ^ 6;
3762 break;
3763 case 0x67: /* address-size override */
3764 if (mode == X86EMUL_MODE_PROT64)
3765 /* switch between 4/8 bytes */
3766 ctxt->ad_bytes = def_ad_bytes ^ 12;
3767 else
3768 /* switch between 2/4 bytes */
3769 ctxt->ad_bytes = def_ad_bytes ^ 6;
3770 break;
3771 case 0x26: /* ES override */
3772 case 0x2e: /* CS override */
3773 case 0x36: /* SS override */
3774 case 0x3e: /* DS override */
3775 set_seg_override(ctxt, (ctxt->b >> 3) & 3);
3776 break;
3777 case 0x64: /* FS override */
3778 case 0x65: /* GS override */
3779 set_seg_override(ctxt, ctxt->b & 7);
3780 break;
3781 case 0x40 ... 0x4f: /* REX */
3782 if (mode != X86EMUL_MODE_PROT64)
3783 goto done_prefixes;
3784 ctxt->rex_prefix = ctxt->b;
3785 continue;
3786 case 0xf0: /* LOCK */
3787 ctxt->lock_prefix = 1;
3788 break;
3789 case 0xf2: /* REPNE/REPNZ */
3790 case 0xf3: /* REP/REPE/REPZ */
3791 ctxt->rep_prefix = ctxt->b;
3792 break;
3793 default:
3794 goto done_prefixes;
3795 }
3796
3797 /* Any legacy prefix after a REX prefix nullifies its effect. */
3798
3799 ctxt->rex_prefix = 0;
3800 }
3801
3802 done_prefixes:
3803
3804 /* REX prefix. */
3805 if (ctxt->rex_prefix & 8)
3806 ctxt->op_bytes = 8; /* REX.W */
3807
3808 /* Opcode byte(s). */
3809 opcode = opcode_table[ctxt->b];
3810 /* Two-byte opcode? */
3811 if (ctxt->b == 0x0f) {
3812 ctxt->twobyte = 1;
3813 ctxt->b = insn_fetch(u8, ctxt);
3814 opcode = twobyte_table[ctxt->b];
3815 }
3816 ctxt->d = opcode.flags;
3817
3818 while (ctxt->d & GroupMask) {
3819 switch (ctxt->d & GroupMask) {
3820 case Group:
3821 ctxt->modrm = insn_fetch(u8, ctxt);
3822 --ctxt->_eip;
3823 goffset = (ctxt->modrm >> 3) & 7;
3824 opcode = opcode.u.group[goffset];
3825 break;
3826 case GroupDual:
3827 ctxt->modrm = insn_fetch(u8, ctxt);
3828 --ctxt->_eip;
3829 goffset = (ctxt->modrm >> 3) & 7;
3830 if ((ctxt->modrm >> 6) == 3)
3831 opcode = opcode.u.gdual->mod3[goffset];
3832 else
3833 opcode = opcode.u.gdual->mod012[goffset];
3834 break;
3835 case RMExt:
3836 goffset = ctxt->modrm & 7;
3837 opcode = opcode.u.group[goffset];
3838 break;
3839 case Prefix:
3840 if (ctxt->rep_prefix && op_prefix)
3841 return EMULATION_FAILED;
3842 simd_prefix = op_prefix ? 0x66 : ctxt->rep_prefix;
3843 switch (simd_prefix) {
3844 case 0x00: opcode = opcode.u.gprefix->pfx_no; break;
3845 case 0x66: opcode = opcode.u.gprefix->pfx_66; break;
3846 case 0xf2: opcode = opcode.u.gprefix->pfx_f2; break;
3847 case 0xf3: opcode = opcode.u.gprefix->pfx_f3; break;
3848 }
3849 break;
3850 default:
3851 return EMULATION_FAILED;
3852 }
3853
3854 ctxt->d &= ~(u64)GroupMask;
3855 ctxt->d |= opcode.flags;
3856 }
3857
3858 ctxt->execute = opcode.u.execute;
3859 ctxt->check_perm = opcode.check_perm;
3860 ctxt->intercept = opcode.intercept;
3861
3862 /* Unrecognised? */
3863 if (ctxt->d == 0 || (ctxt->d & Undefined))
3864 return EMULATION_FAILED;
3865
3866 if (!(ctxt->d & VendorSpecific) && ctxt->only_vendor_specific_insn)
3867 return EMULATION_FAILED;
3868
3869 if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack))
3870 ctxt->op_bytes = 8;
3871
3872 if (ctxt->d & Op3264) {
3873 if (mode == X86EMUL_MODE_PROT64)
3874 ctxt->op_bytes = 8;
3875 else
3876 ctxt->op_bytes = 4;
3877 }
3878
3879 if (ctxt->d & Sse)
3880 ctxt->op_bytes = 16;
3881
3882 /* ModRM and SIB bytes. */
3883 if (ctxt->d & ModRM) {
3884 rc = decode_modrm(ctxt, &ctxt->memop);
3885 if (!ctxt->has_seg_override)
3886 set_seg_override(ctxt, ctxt->modrm_seg);
3887 } else if (ctxt->d & MemAbs)
3888 rc = decode_abs(ctxt, &ctxt->memop);
3889 if (rc != X86EMUL_CONTINUE)
3890 goto done;
3891
3892 if (!ctxt->has_seg_override)
3893 set_seg_override(ctxt, VCPU_SREG_DS);
3894
3895 ctxt->memop.addr.mem.seg = seg_override(ctxt);
3896
3897 if (ctxt->memop.type == OP_MEM && ctxt->ad_bytes != 8)
3898 ctxt->memop.addr.mem.ea = (u32)ctxt->memop.addr.mem.ea;
3899
3900 /*
3901 * Decode and fetch the source operand: register, memory
3902 * or immediate.
3903 */
3904 rc = decode_operand(ctxt, &ctxt->src, (ctxt->d >> SrcShift) & OpMask);
3905 if (rc != X86EMUL_CONTINUE)
3906 goto done;
3907
3908 /*
3909 * Decode and fetch the second source operand: register, memory
3910 * or immediate.
3911 */
3912 rc = decode_operand(ctxt, &ctxt->src2, (ctxt->d >> Src2Shift) & OpMask);
3913 if (rc != X86EMUL_CONTINUE)
3914 goto done;
3915
3916 /* Decode and fetch the destination operand: register or memory. */
3917 rc = decode_operand(ctxt, &ctxt->dst, (ctxt->d >> DstShift) & OpMask);
3918
3919 done:
3920 if (ctxt->memopp && ctxt->memopp->type == OP_MEM && ctxt->rip_relative)
3921 ctxt->memopp->addr.mem.ea += ctxt->_eip;
3922
3923 return (rc != X86EMUL_CONTINUE) ? EMULATION_FAILED : EMULATION_OK;
3924 }
3925
3926 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt)
3927 {
3928 return ctxt->d & PageTable;
3929 }
3930
3931 static bool string_insn_completed(struct x86_emulate_ctxt *ctxt)
3932 {
3933 /* The second termination condition only applies for REPE
3934 * and REPNE. Test if the repeat string operation prefix is
3935 * REPE/REPZ or REPNE/REPNZ and if it's the case it tests the
3936 * corresponding termination condition according to:
3937 * - if REPE/REPZ and ZF = 0 then done
3938 * - if REPNE/REPNZ and ZF = 1 then done
3939 */
3940 if (((ctxt->b == 0xa6) || (ctxt->b == 0xa7) ||
3941 (ctxt->b == 0xae) || (ctxt->b == 0xaf))
3942 && (((ctxt->rep_prefix == REPE_PREFIX) &&
3943 ((ctxt->eflags & EFLG_ZF) == 0))
3944 || ((ctxt->rep_prefix == REPNE_PREFIX) &&
3945 ((ctxt->eflags & EFLG_ZF) == EFLG_ZF))))
3946 return true;
3947
3948 return false;
3949 }
3950
3951 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt)
3952 {
3953 struct x86_emulate_ops *ops = ctxt->ops;
3954 int rc = X86EMUL_CONTINUE;
3955 int saved_dst_type = ctxt->dst.type;
3956
3957 ctxt->mem_read.pos = 0;
3958
3959 if (ctxt->mode == X86EMUL_MODE_PROT64 && (ctxt->d & No64)) {
3960 rc = emulate_ud(ctxt);
3961 goto done;
3962 }
3963
3964 /* LOCK prefix is allowed only with some instructions */
3965 if (ctxt->lock_prefix && (!(ctxt->d & Lock) || ctxt->dst.type != OP_MEM)) {
3966 rc = emulate_ud(ctxt);
3967 goto done;
3968 }
3969
3970 if ((ctxt->d & SrcMask) == SrcMemFAddr && ctxt->src.type != OP_MEM) {
3971 rc = emulate_ud(ctxt);
3972 goto done;
3973 }
3974
3975 if ((ctxt->d & Sse)
3976 && ((ops->get_cr(ctxt, 0) & X86_CR0_EM)
3977 || !(ops->get_cr(ctxt, 4) & X86_CR4_OSFXSR))) {
3978 rc = emulate_ud(ctxt);
3979 goto done;
3980 }
3981
3982 if ((ctxt->d & Sse) && (ops->get_cr(ctxt, 0) & X86_CR0_TS)) {
3983 rc = emulate_nm(ctxt);
3984 goto done;
3985 }
3986
3987 if (unlikely(ctxt->guest_mode) && ctxt->intercept) {
3988 rc = emulator_check_intercept(ctxt, ctxt->intercept,
3989 X86_ICPT_PRE_EXCEPT);
3990 if (rc != X86EMUL_CONTINUE)
3991 goto done;
3992 }
3993
3994 /* Privileged instruction can be executed only in CPL=0 */
3995 if ((ctxt->d & Priv) && ops->cpl(ctxt)) {
3996 rc = emulate_gp(ctxt, 0);
3997 goto done;
3998 }
3999
4000 /* Instruction can only be executed in protected mode */
4001 if ((ctxt->d & Prot) && !(ctxt->mode & X86EMUL_MODE_PROT)) {
4002 rc = emulate_ud(ctxt);
4003 goto done;
4004 }
4005
4006 /* Do instruction specific permission checks */
4007 if (ctxt->check_perm) {
4008 rc = ctxt->check_perm(ctxt);
4009 if (rc != X86EMUL_CONTINUE)
4010 goto done;
4011 }
4012
4013 if (unlikely(ctxt->guest_mode) && ctxt->intercept) {
4014 rc = emulator_check_intercept(ctxt, ctxt->intercept,
4015 X86_ICPT_POST_EXCEPT);
4016 if (rc != X86EMUL_CONTINUE)
4017 goto done;
4018 }
4019
4020 if (ctxt->rep_prefix && (ctxt->d & String)) {
4021 /* All REP prefixes have the same first termination condition */
4022 if (address_mask(ctxt, ctxt->regs[VCPU_REGS_RCX]) == 0) {
4023 ctxt->eip = ctxt->_eip;
4024 goto done;
4025 }
4026 }
4027
4028 if ((ctxt->src.type == OP_MEM) && !(ctxt->d & NoAccess)) {
4029 rc = segmented_read(ctxt, ctxt->src.addr.mem,
4030 ctxt->src.valptr, ctxt->src.bytes);
4031 if (rc != X86EMUL_CONTINUE)
4032 goto done;
4033 ctxt->src.orig_val64 = ctxt->src.val64;
4034 }
4035
4036 if (ctxt->src2.type == OP_MEM) {
4037 rc = segmented_read(ctxt, ctxt->src2.addr.mem,
4038 &ctxt->src2.val, ctxt->src2.bytes);
4039 if (rc != X86EMUL_CONTINUE)
4040 goto done;
4041 }
4042
4043 if ((ctxt->d & DstMask) == ImplicitOps)
4044 goto special_insn;
4045
4046
4047 if ((ctxt->dst.type == OP_MEM) && !(ctxt->d & Mov)) {
4048 /* optimisation - avoid slow emulated read if Mov */
4049 rc = segmented_read(ctxt, ctxt->dst.addr.mem,
4050 &ctxt->dst.val, ctxt->dst.bytes);
4051 if (rc != X86EMUL_CONTINUE)
4052 goto done;
4053 }
4054 ctxt->dst.orig_val = ctxt->dst.val;
4055
4056 special_insn:
4057
4058 if (unlikely(ctxt->guest_mode) && ctxt->intercept) {
4059 rc = emulator_check_intercept(ctxt, ctxt->intercept,
4060 X86_ICPT_POST_MEMACCESS);
4061 if (rc != X86EMUL_CONTINUE)
4062 goto done;
4063 }
4064
4065 if (ctxt->execute) {
4066 rc = ctxt->execute(ctxt);
4067 if (rc != X86EMUL_CONTINUE)
4068 goto done;
4069 goto writeback;
4070 }
4071
4072 if (ctxt->twobyte)
4073 goto twobyte_insn;
4074
4075 switch (ctxt->b) {
4076 case 0x40 ... 0x47: /* inc r16/r32 */
4077 emulate_1op(ctxt, "inc");
4078 break;
4079 case 0x48 ... 0x4f: /* dec r16/r32 */
4080 emulate_1op(ctxt, "dec");
4081 break;
4082 case 0x63: /* movsxd */
4083 if (ctxt->mode != X86EMUL_MODE_PROT64)
4084 goto cannot_emulate;
4085 ctxt->dst.val = (s32) ctxt->src.val;
4086 break;
4087 case 0x70 ... 0x7f: /* jcc (short) */
4088 if (test_cc(ctxt->b, ctxt->eflags))
4089 jmp_rel(ctxt, ctxt->src.val);
4090 break;
4091 case 0x8d: /* lea r16/r32, m */
4092 ctxt->dst.val = ctxt->src.addr.mem.ea;
4093 break;
4094 case 0x90 ... 0x97: /* nop / xchg reg, rax */
4095 if (ctxt->dst.addr.reg == &ctxt->regs[VCPU_REGS_RAX])
4096 break;
4097 rc = em_xchg(ctxt);
4098 break;
4099 case 0x98: /* cbw/cwde/cdqe */
4100 switch (ctxt->op_bytes) {
4101 case 2: ctxt->dst.val = (s8)ctxt->dst.val; break;
4102 case 4: ctxt->dst.val = (s16)ctxt->dst.val; break;
4103 case 8: ctxt->dst.val = (s32)ctxt->dst.val; break;
4104 }
4105 break;
4106 case 0xc0 ... 0xc1:
4107 rc = em_grp2(ctxt);
4108 break;
4109 case 0xcc: /* int3 */
4110 rc = emulate_int(ctxt, 3);
4111 break;
4112 case 0xcd: /* int n */
4113 rc = emulate_int(ctxt, ctxt->src.val);
4114 break;
4115 case 0xce: /* into */
4116 if (ctxt->eflags & EFLG_OF)
4117 rc = emulate_int(ctxt, 4);
4118 break;
4119 case 0xd0 ... 0xd1: /* Grp2 */
4120 rc = em_grp2(ctxt);
4121 break;
4122 case 0xd2 ... 0xd3: /* Grp2 */
4123 ctxt->src.val = ctxt->regs[VCPU_REGS_RCX];
4124 rc = em_grp2(ctxt);
4125 break;
4126 case 0xe9: /* jmp rel */
4127 case 0xeb: /* jmp rel short */
4128 jmp_rel(ctxt, ctxt->src.val);
4129 ctxt->dst.type = OP_NONE; /* Disable writeback. */
4130 break;
4131 case 0xf4: /* hlt */
4132 ctxt->ops->halt(ctxt);
4133 break;
4134 case 0xf5: /* cmc */
4135 /* complement carry flag from eflags reg */
4136 ctxt->eflags ^= EFLG_CF;
4137 break;
4138 case 0xf8: /* clc */
4139 ctxt->eflags &= ~EFLG_CF;
4140 break;
4141 case 0xf9: /* stc */
4142 ctxt->eflags |= EFLG_CF;
4143 break;
4144 case 0xfc: /* cld */
4145 ctxt->eflags &= ~EFLG_DF;
4146 break;
4147 case 0xfd: /* std */
4148 ctxt->eflags |= EFLG_DF;
4149 break;
4150 default:
4151 goto cannot_emulate;
4152 }
4153
4154 if (rc != X86EMUL_CONTINUE)
4155 goto done;
4156
4157 writeback:
4158 rc = writeback(ctxt);
4159 if (rc != X86EMUL_CONTINUE)
4160 goto done;
4161
4162 /*
4163 * restore dst type in case the decoding will be reused
4164 * (happens for string instruction )
4165 */
4166 ctxt->dst.type = saved_dst_type;
4167
4168 if ((ctxt->d & SrcMask) == SrcSI)
4169 string_addr_inc(ctxt, seg_override(ctxt),
4170 VCPU_REGS_RSI, &ctxt->src);
4171
4172 if ((ctxt->d & DstMask) == DstDI)
4173 string_addr_inc(ctxt, VCPU_SREG_ES, VCPU_REGS_RDI,
4174 &ctxt->dst);
4175
4176 if (ctxt->rep_prefix && (ctxt->d & String)) {
4177 struct read_cache *r = &ctxt->io_read;
4178 register_address_increment(ctxt, &ctxt->regs[VCPU_REGS_RCX], -1);
4179
4180 if (!string_insn_completed(ctxt)) {
4181 /*
4182 * Re-enter guest when pio read ahead buffer is empty
4183 * or, if it is not used, after each 1024 iteration.
4184 */
4185 if ((r->end != 0 || ctxt->regs[VCPU_REGS_RCX] & 0x3ff) &&
4186 (r->end == 0 || r->end != r->pos)) {
4187 /*
4188 * Reset read cache. Usually happens before
4189 * decode, but since instruction is restarted
4190 * we have to do it here.
4191 */
4192 ctxt->mem_read.end = 0;
4193 return EMULATION_RESTART;
4194 }
4195 goto done; /* skip rip writeback */
4196 }
4197 }
4198
4199 ctxt->eip = ctxt->_eip;
4200
4201 done:
4202 if (rc == X86EMUL_PROPAGATE_FAULT)
4203 ctxt->have_exception = true;
4204 if (rc == X86EMUL_INTERCEPTED)
4205 return EMULATION_INTERCEPTED;
4206
4207 return (rc == X86EMUL_UNHANDLEABLE) ? EMULATION_FAILED : EMULATION_OK;
4208
4209 twobyte_insn:
4210 switch (ctxt->b) {
4211 case 0x09: /* wbinvd */
4212 (ctxt->ops->wbinvd)(ctxt);
4213 break;
4214 case 0x08: /* invd */
4215 case 0x0d: /* GrpP (prefetch) */
4216 case 0x18: /* Grp16 (prefetch/nop) */
4217 break;
4218 case 0x20: /* mov cr, reg */
4219 ctxt->dst.val = ops->get_cr(ctxt, ctxt->modrm_reg);
4220 break;
4221 case 0x21: /* mov from dr to reg */
4222 ops->get_dr(ctxt, ctxt->modrm_reg, &ctxt->dst.val);
4223 break;
4224 case 0x40 ... 0x4f: /* cmov */
4225 ctxt->dst.val = ctxt->dst.orig_val = ctxt->src.val;
4226 if (!test_cc(ctxt->b, ctxt->eflags))
4227 ctxt->dst.type = OP_NONE; /* no writeback */
4228 break;
4229 case 0x80 ... 0x8f: /* jnz rel, etc*/
4230 if (test_cc(ctxt->b, ctxt->eflags))
4231 jmp_rel(ctxt, ctxt->src.val);
4232 break;
4233 case 0x90 ... 0x9f: /* setcc r/m8 */
4234 ctxt->dst.val = test_cc(ctxt->b, ctxt->eflags);
4235 break;
4236 case 0xa4: /* shld imm8, r, r/m */
4237 case 0xa5: /* shld cl, r, r/m */
4238 emulate_2op_cl(ctxt, "shld");
4239 break;
4240 case 0xac: /* shrd imm8, r, r/m */
4241 case 0xad: /* shrd cl, r, r/m */
4242 emulate_2op_cl(ctxt, "shrd");
4243 break;
4244 case 0xae: /* clflush */
4245 break;
4246 case 0xb6 ... 0xb7: /* movzx */
4247 ctxt->dst.bytes = ctxt->op_bytes;
4248 ctxt->dst.val = (ctxt->d & ByteOp) ? (u8) ctxt->src.val
4249 : (u16) ctxt->src.val;
4250 break;
4251 case 0xbe ... 0xbf: /* movsx */
4252 ctxt->dst.bytes = ctxt->op_bytes;
4253 ctxt->dst.val = (ctxt->d & ByteOp) ? (s8) ctxt->src.val :
4254 (s16) ctxt->src.val;
4255 break;
4256 case 0xc0 ... 0xc1: /* xadd */
4257 emulate_2op_SrcV(ctxt, "add");
4258 /* Write back the register source. */
4259 ctxt->src.val = ctxt->dst.orig_val;
4260 write_register_operand(&ctxt->src);
4261 break;
4262 case 0xc3: /* movnti */
4263 ctxt->dst.bytes = ctxt->op_bytes;
4264 ctxt->dst.val = (ctxt->op_bytes == 4) ? (u32) ctxt->src.val :
4265 (u64) ctxt->src.val;
4266 break;
4267 default:
4268 goto cannot_emulate;
4269 }
4270
4271 if (rc != X86EMUL_CONTINUE)
4272 goto done;
4273
4274 goto writeback;
4275
4276 cannot_emulate:
4277 return EMULATION_FAILED;
4278 }