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diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c
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1/******************************************************************************
2 * x86_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 *
13 * Avi Kivity <avi@qumranet.com>
14 * Yaniv Kamay <yaniv@qumranet.com>
15 *
16 * This work is licensed under the terms of the GNU GPL, version 2. See
17 * the COPYING file in the top-level directory.
18 *
19 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
20 */
21
22#ifndef __KERNEL__
23#include <stdio.h>
24#include <stdint.h>
25#include <public/xen.h>
26#define DPRINTF(_f, _a ...) printf( _f , ## _a )
27#else
28#include "kvm.h"
29#define DPRINTF(x...) do {} while (0)
30#endif
31#include "x86_emulate.h"
32#include <linux/module.h>
33
34/*
35 * Opcode effective-address decode tables.
36 * Note that we only emulate instructions that have at least one memory
37 * operand (excluding implicit stack references). We assume that stack
38 * references and instruction fetches will never occur in special memory
39 * areas that require emulation. So, for example, 'mov <imm>,<reg>' need
40 * not be handled.
41 */
42
43/* Operand sizes: 8-bit operands or specified/overridden size. */
44#define ByteOp (1<<0) /* 8-bit operands. */
45/* Destination operand type. */
46#define ImplicitOps (1<<1) /* Implicit in opcode. No generic decode. */
47#define DstReg (2<<1) /* Register operand. */
48#define DstMem (3<<1) /* Memory operand. */
49#define DstMask (3<<1)
50/* Source operand type. */
51#define SrcNone (0<<3) /* No source operand. */
52#define SrcImplicit (0<<3) /* Source operand is implicit in the opcode. */
53#define SrcReg (1<<3) /* Register operand. */
54#define SrcMem (2<<3) /* Memory operand. */
55#define SrcMem16 (3<<3) /* Memory operand (16-bit). */
56#define SrcMem32 (4<<3) /* Memory operand (32-bit). */
57#define SrcImm (5<<3) /* Immediate operand. */
58#define SrcImmByte (6<<3) /* 8-bit sign-extended immediate operand. */
59#define SrcMask (7<<3)
60/* Generic ModRM decode. */
61#define ModRM (1<<6)
62/* Destination is only written; never read. */
63#define Mov (1<<7)
64#define BitOp (1<<8)
65
66static u8 opcode_table[256] = {
67 /* 0x00 - 0x07 */
68 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
69 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
70 0, 0, 0, 0,
71 /* 0x08 - 0x0F */
72 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
73 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
74 0, 0, 0, 0,
75 /* 0x10 - 0x17 */
76 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
77 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
78 0, 0, 0, 0,
79 /* 0x18 - 0x1F */
80 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
81 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
82 0, 0, 0, 0,
83 /* 0x20 - 0x27 */
84 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
85 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
86 SrcImmByte, SrcImm, 0, 0,
87 /* 0x28 - 0x2F */
88 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
89 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
90 0, 0, 0, 0,
91 /* 0x30 - 0x37 */
92 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
93 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
94 0, 0, 0, 0,
95 /* 0x38 - 0x3F */
96 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
97 ByteOp | DstReg | SrcMem | ModRM, DstReg | SrcMem | ModRM,
98 0, 0, 0, 0,
99 /* 0x40 - 0x4F */
100 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
101 /* 0x50 - 0x57 */
102 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
103 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
104 /* 0x58 - 0x5F */
105 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
106 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
107 /* 0x60 - 0x67 */
108 0, 0, 0, DstReg | SrcMem32 | ModRM | Mov /* movsxd (x86/64) */ ,
109 0, 0, 0, 0,
110 /* 0x68 - 0x6F */
111 0, 0, ImplicitOps|Mov, 0,
112 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* insb, insw/insd */
113 SrcNone | ByteOp | ImplicitOps, SrcNone | ImplicitOps, /* outsb, outsw/outsd */
114 /* 0x70 - 0x77 */
115 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
116 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
117 /* 0x78 - 0x7F */
118 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
119 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
120 /* 0x80 - 0x87 */
121 ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImm | ModRM,
122 ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM,
123 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
124 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM,
125 /* 0x88 - 0x8F */
126 ByteOp | DstMem | SrcReg | ModRM | Mov, DstMem | SrcReg | ModRM | Mov,
127 ByteOp | DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
128 0, ModRM | DstReg, 0, DstMem | SrcNone | ModRM | Mov,
129 /* 0x90 - 0x9F */
130 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps, ImplicitOps, 0, 0,
131 /* 0xA0 - 0xA7 */
132 ByteOp | DstReg | SrcMem | Mov, DstReg | SrcMem | Mov,
133 ByteOp | DstMem | SrcReg | Mov, DstMem | SrcReg | Mov,
134 ByteOp | ImplicitOps | Mov, ImplicitOps | Mov,
135 ByteOp | ImplicitOps, ImplicitOps,
136 /* 0xA8 - 0xAF */
137 0, 0, ByteOp | ImplicitOps | Mov, ImplicitOps | Mov,
138 ByteOp | ImplicitOps | Mov, ImplicitOps | Mov,
139 ByteOp | ImplicitOps, ImplicitOps,
140 /* 0xB0 - 0xBF */
141 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
142 /* 0xC0 - 0xC7 */
143 ByteOp | DstMem | SrcImm | ModRM, DstMem | SrcImmByte | ModRM,
144 0, ImplicitOps, 0, 0,
145 ByteOp | DstMem | SrcImm | ModRM | Mov, DstMem | SrcImm | ModRM | Mov,
146 /* 0xC8 - 0xCF */
147 0, 0, 0, 0, 0, 0, 0, 0,
148 /* 0xD0 - 0xD7 */
149 ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM,
150 ByteOp | DstMem | SrcImplicit | ModRM, DstMem | SrcImplicit | ModRM,
151 0, 0, 0, 0,
152 /* 0xD8 - 0xDF */
153 0, 0, 0, 0, 0, 0, 0, 0,
154 /* 0xE0 - 0xE7 */
155 0, 0, 0, 0, 0, 0, 0, 0,
156 /* 0xE8 - 0xEF */
157 ImplicitOps, SrcImm|ImplicitOps, 0, SrcImmByte|ImplicitOps, 0, 0, 0, 0,
158 /* 0xF0 - 0xF7 */
159 0, 0, 0, 0,
160 ImplicitOps, 0,
161 ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM,
162 /* 0xF8 - 0xFF */
163 0, 0, 0, 0,
164 0, 0, ByteOp | DstMem | SrcNone | ModRM, DstMem | SrcNone | ModRM
165};
166
167static u16 twobyte_table[256] = {
168 /* 0x00 - 0x0F */
169 0, SrcMem | ModRM | DstReg, 0, 0, 0, 0, ImplicitOps, 0,
170 ImplicitOps, ImplicitOps, 0, 0, 0, ImplicitOps | ModRM, 0, 0,
171 /* 0x10 - 0x1F */
172 0, 0, 0, 0, 0, 0, 0, 0, ImplicitOps | ModRM, 0, 0, 0, 0, 0, 0, 0,
173 /* 0x20 - 0x2F */
174 ModRM | ImplicitOps, ModRM, ModRM | ImplicitOps, ModRM, 0, 0, 0, 0,
175 0, 0, 0, 0, 0, 0, 0, 0,
176 /* 0x30 - 0x3F */
177 ImplicitOps, 0, ImplicitOps, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
178 /* 0x40 - 0x47 */
179 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
180 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
181 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
182 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
183 /* 0x48 - 0x4F */
184 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
185 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
186 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
187 DstReg | SrcMem | ModRM | Mov, DstReg | SrcMem | ModRM | Mov,
188 /* 0x50 - 0x5F */
189 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
190 /* 0x60 - 0x6F */
191 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
192 /* 0x70 - 0x7F */
193 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
194 /* 0x80 - 0x8F */
195 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
196 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
197 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
198 ImplicitOps, ImplicitOps, ImplicitOps, ImplicitOps,
199 /* 0x90 - 0x9F */
200 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
201 /* 0xA0 - 0xA7 */
202 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0,
203 /* 0xA8 - 0xAF */
204 0, 0, 0, DstMem | SrcReg | ModRM | BitOp, 0, 0, 0, 0,
205 /* 0xB0 - 0xB7 */
206 ByteOp | DstMem | SrcReg | ModRM, DstMem | SrcReg | ModRM, 0,
207 DstMem | SrcReg | ModRM | BitOp,
208 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
209 DstReg | SrcMem16 | ModRM | Mov,
210 /* 0xB8 - 0xBF */
211 0, 0, DstMem | SrcImmByte | ModRM, DstMem | SrcReg | ModRM | BitOp,
212 0, 0, ByteOp | DstReg | SrcMem | ModRM | Mov,
213 DstReg | SrcMem16 | ModRM | Mov,
214 /* 0xC0 - 0xCF */
215 0, 0, 0, DstMem | SrcReg | ModRM | Mov, 0, 0, 0, ImplicitOps | ModRM,
216 0, 0, 0, 0, 0, 0, 0, 0,
217 /* 0xD0 - 0xDF */
218 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
219 /* 0xE0 - 0xEF */
220 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
221 /* 0xF0 - 0xFF */
222 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
223};
224
225/* Type, address-of, and value of an instruction's operand. */
226struct operand {
227 enum { OP_REG, OP_MEM, OP_IMM } type;
228 unsigned int bytes;
229 unsigned long val, orig_val, *ptr;
230};
231
232/* EFLAGS bit definitions. */
233#define EFLG_OF (1<<11)
234#define EFLG_DF (1<<10)
235#define EFLG_SF (1<<7)
236#define EFLG_ZF (1<<6)
237#define EFLG_AF (1<<4)
238#define EFLG_PF (1<<2)
239#define EFLG_CF (1<<0)
240
241/*
242 * Instruction emulation:
243 * Most instructions are emulated directly via a fragment of inline assembly
244 * code. This allows us to save/restore EFLAGS and thus very easily pick up
245 * any modified flags.
246 */
247
248#if defined(CONFIG_X86_64)
249#define _LO32 "k" /* force 32-bit operand */
250#define _STK "%%rsp" /* stack pointer */
251#elif defined(__i386__)
252#define _LO32 "" /* force 32-bit operand */
253#define _STK "%%esp" /* stack pointer */
254#endif
255
256/*
257 * These EFLAGS bits are restored from saved value during emulation, and
258 * any changes are written back to the saved value after emulation.
259 */
260#define EFLAGS_MASK (EFLG_OF|EFLG_SF|EFLG_ZF|EFLG_AF|EFLG_PF|EFLG_CF)
261
262/* Before executing instruction: restore necessary bits in EFLAGS. */
263#define _PRE_EFLAGS(_sav, _msk, _tmp) \
264 /* EFLAGS = (_sav & _msk) | (EFLAGS & ~_msk); */ \
265 "push %"_sav"; " \
266 "movl %"_msk",%"_LO32 _tmp"; " \
267 "andl %"_LO32 _tmp",("_STK"); " \
268 "pushf; " \
269 "notl %"_LO32 _tmp"; " \
270 "andl %"_LO32 _tmp",("_STK"); " \
271 "pop %"_tmp"; " \
272 "orl %"_LO32 _tmp",("_STK"); " \
273 "popf; " \
274 /* _sav &= ~msk; */ \
275 "movl %"_msk",%"_LO32 _tmp"; " \
276 "notl %"_LO32 _tmp"; " \
277 "andl %"_LO32 _tmp",%"_sav"; "
278
279/* After executing instruction: write-back necessary bits in EFLAGS. */
280#define _POST_EFLAGS(_sav, _msk, _tmp) \
281 /* _sav |= EFLAGS & _msk; */ \
282 "pushf; " \
283 "pop %"_tmp"; " \
284 "andl %"_msk",%"_LO32 _tmp"; " \
285 "orl %"_LO32 _tmp",%"_sav"; "
286
287/* Raw emulation: instruction has two explicit operands. */
288#define __emulate_2op_nobyte(_op,_src,_dst,_eflags,_wx,_wy,_lx,_ly,_qx,_qy) \
289 do { \
290 unsigned long _tmp; \
291 \
292 switch ((_dst).bytes) { \
293 case 2: \
294 __asm__ __volatile__ ( \
295 _PRE_EFLAGS("0","4","2") \
296 _op"w %"_wx"3,%1; " \
297 _POST_EFLAGS("0","4","2") \
298 : "=m" (_eflags), "=m" ((_dst).val), \
299 "=&r" (_tmp) \
300 : _wy ((_src).val), "i" (EFLAGS_MASK) ); \
301 break; \
302 case 4: \
303 __asm__ __volatile__ ( \
304 _PRE_EFLAGS("0","4","2") \
305 _op"l %"_lx"3,%1; " \
306 _POST_EFLAGS("0","4","2") \
307 : "=m" (_eflags), "=m" ((_dst).val), \
308 "=&r" (_tmp) \
309 : _ly ((_src).val), "i" (EFLAGS_MASK) ); \
310 break; \
311 case 8: \
312 __emulate_2op_8byte(_op, _src, _dst, \
313 _eflags, _qx, _qy); \
314 break; \
315 } \
316 } while (0)
317
318#define __emulate_2op(_op,_src,_dst,_eflags,_bx,_by,_wx,_wy,_lx,_ly,_qx,_qy) \
319 do { \
320 unsigned long _tmp; \
321 switch ( (_dst).bytes ) \
322 { \
323 case 1: \
324 __asm__ __volatile__ ( \
325 _PRE_EFLAGS("0","4","2") \
326 _op"b %"_bx"3,%1; " \
327 _POST_EFLAGS("0","4","2") \
328 : "=m" (_eflags), "=m" ((_dst).val), \
329 "=&r" (_tmp) \
330 : _by ((_src).val), "i" (EFLAGS_MASK) ); \
331 break; \
332 default: \
333 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
334 _wx, _wy, _lx, _ly, _qx, _qy); \
335 break; \
336 } \
337 } while (0)
338
339/* Source operand is byte-sized and may be restricted to just %cl. */
340#define emulate_2op_SrcB(_op, _src, _dst, _eflags) \
341 __emulate_2op(_op, _src, _dst, _eflags, \
342 "b", "c", "b", "c", "b", "c", "b", "c")
343
344/* Source operand is byte, word, long or quad sized. */
345#define emulate_2op_SrcV(_op, _src, _dst, _eflags) \
346 __emulate_2op(_op, _src, _dst, _eflags, \
347 "b", "q", "w", "r", _LO32, "r", "", "r")
348
349/* Source operand is word, long or quad sized. */
350#define emulate_2op_SrcV_nobyte(_op, _src, _dst, _eflags) \
351 __emulate_2op_nobyte(_op, _src, _dst, _eflags, \
352 "w", "r", _LO32, "r", "", "r")
353
354/* Instruction has only one explicit operand (no source operand). */
355#define emulate_1op(_op, _dst, _eflags) \
356 do { \
357 unsigned long _tmp; \
358 \
359 switch ( (_dst).bytes ) \
360 { \
361 case 1: \
362 __asm__ __volatile__ ( \
363 _PRE_EFLAGS("0","3","2") \
364 _op"b %1; " \
365 _POST_EFLAGS("0","3","2") \
366 : "=m" (_eflags), "=m" ((_dst).val), \
367 "=&r" (_tmp) \
368 : "i" (EFLAGS_MASK) ); \
369 break; \
370 case 2: \
371 __asm__ __volatile__ ( \
372 _PRE_EFLAGS("0","3","2") \
373 _op"w %1; " \
374 _POST_EFLAGS("0","3","2") \
375 : "=m" (_eflags), "=m" ((_dst).val), \
376 "=&r" (_tmp) \
377 : "i" (EFLAGS_MASK) ); \
378 break; \
379 case 4: \
380 __asm__ __volatile__ ( \
381 _PRE_EFLAGS("0","3","2") \
382 _op"l %1; " \
383 _POST_EFLAGS("0","3","2") \
384 : "=m" (_eflags), "=m" ((_dst).val), \
385 "=&r" (_tmp) \
386 : "i" (EFLAGS_MASK) ); \
387 break; \
388 case 8: \
389 __emulate_1op_8byte(_op, _dst, _eflags); \
390 break; \
391 } \
392 } while (0)
393
394/* Emulate an instruction with quadword operands (x86/64 only). */
395#if defined(CONFIG_X86_64)
396#define __emulate_2op_8byte(_op, _src, _dst, _eflags, _qx, _qy) \
397 do { \
398 __asm__ __volatile__ ( \
399 _PRE_EFLAGS("0","4","2") \
400 _op"q %"_qx"3,%1; " \
401 _POST_EFLAGS("0","4","2") \
402 : "=m" (_eflags), "=m" ((_dst).val), "=&r" (_tmp) \
403 : _qy ((_src).val), "i" (EFLAGS_MASK) ); \
404 } while (0)
405
406#define __emulate_1op_8byte(_op, _dst, _eflags) \
407 do { \
408 __asm__ __volatile__ ( \
409 _PRE_EFLAGS("0","3","2") \
410 _op"q %1; " \
411 _POST_EFLAGS("0","3","2") \
412 : "=m" (_eflags), "=m" ((_dst).val), "=&r" (_tmp) \
413 : "i" (EFLAGS_MASK) ); \
414 } while (0)
415
416#elif defined(__i386__)
417#define __emulate_2op_8byte(_op, _src, _dst, _eflags, _qx, _qy)
418#define __emulate_1op_8byte(_op, _dst, _eflags)
419#endif /* __i386__ */
420
421/* Fetch next part of the instruction being emulated. */
422#define insn_fetch(_type, _size, _eip) \
423({ unsigned long _x; \
424 rc = ops->read_std((unsigned long)(_eip) + ctxt->cs_base, &_x, \
425 (_size), ctxt->vcpu); \
426 if ( rc != 0 ) \
427 goto done; \
428 (_eip) += (_size); \
429 (_type)_x; \
430})
431
432/* Access/update address held in a register, based on addressing mode. */
433#define address_mask(reg) \
434 ((ad_bytes == sizeof(unsigned long)) ? \
435 (reg) : ((reg) & ((1UL << (ad_bytes << 3)) - 1)))
436#define register_address(base, reg) \
437 ((base) + address_mask(reg))
438#define register_address_increment(reg, inc) \
439 do { \
440 /* signed type ensures sign extension to long */ \
441 int _inc = (inc); \
442 if ( ad_bytes == sizeof(unsigned long) ) \
443 (reg) += _inc; \
444 else \
445 (reg) = ((reg) & ~((1UL << (ad_bytes << 3)) - 1)) | \
446 (((reg) + _inc) & ((1UL << (ad_bytes << 3)) - 1)); \
447 } while (0)
448
449#define JMP_REL(rel) \
450 do { \
451 register_address_increment(_eip, rel); \
452 } while (0)
453
454/*
455 * Given the 'reg' portion of a ModRM byte, and a register block, return a
456 * pointer into the block that addresses the relevant register.
457 * @highbyte_regs specifies whether to decode AH,CH,DH,BH.
458 */
459static void *decode_register(u8 modrm_reg, unsigned long *regs,
460 int highbyte_regs)
461{
462 void *p;
463
464 p = &regs[modrm_reg];
465 if (highbyte_regs && modrm_reg >= 4 && modrm_reg < 8)
466 p = (unsigned char *)&regs[modrm_reg & 3] + 1;
467 return p;
468}
469
470static int read_descriptor(struct x86_emulate_ctxt *ctxt,
471 struct x86_emulate_ops *ops,
472 void *ptr,
473 u16 *size, unsigned long *address, int op_bytes)
474{
475 int rc;
476
477 if (op_bytes == 2)
478 op_bytes = 3;
479 *address = 0;
480 rc = ops->read_std((unsigned long)ptr, (unsigned long *)size, 2,
481 ctxt->vcpu);
482 if (rc)
483 return rc;
484 rc = ops->read_std((unsigned long)ptr + 2, address, op_bytes,
485 ctxt->vcpu);
486 return rc;
487}
488
489static int test_cc(unsigned int condition, unsigned int flags)
490{
491 int rc = 0;
492
493 switch ((condition & 15) >> 1) {
494 case 0: /* o */
495 rc |= (flags & EFLG_OF);
496 break;
497 case 1: /* b/c/nae */
498 rc |= (flags & EFLG_CF);
499 break;
500 case 2: /* z/e */
501 rc |= (flags & EFLG_ZF);
502 break;
503 case 3: /* be/na */
504 rc |= (flags & (EFLG_CF|EFLG_ZF));
505 break;
506 case 4: /* s */
507 rc |= (flags & EFLG_SF);
508 break;
509 case 5: /* p/pe */
510 rc |= (flags & EFLG_PF);
511 break;
512 case 7: /* le/ng */
513 rc |= (flags & EFLG_ZF);
514 /* fall through */
515 case 6: /* l/nge */
516 rc |= (!(flags & EFLG_SF) != !(flags & EFLG_OF));
517 break;
518 }
519
520 /* Odd condition identifiers (lsb == 1) have inverted sense. */
521 return (!!rc ^ (condition & 1));
522}
523
524int
525x86_emulate_memop(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
526{
527 unsigned d;
528 u8 b, sib, twobyte = 0, rex_prefix = 0;
529 u8 modrm, modrm_mod = 0, modrm_reg = 0, modrm_rm = 0;
530 unsigned long *override_base = NULL;
531 unsigned int op_bytes, ad_bytes, lock_prefix = 0, rep_prefix = 0, i;
532 int rc = 0;
533 struct operand src, dst;
534 unsigned long cr2 = ctxt->cr2;
535 int mode = ctxt->mode;
536 unsigned long modrm_ea;
537 int use_modrm_ea, index_reg = 0, base_reg = 0, scale, rip_relative = 0;
538 int no_wb = 0;
539 u64 msr_data;
540
541 /* Shadow copy of register state. Committed on successful emulation. */
542 unsigned long _regs[NR_VCPU_REGS];
543 unsigned long _eip = ctxt->vcpu->rip, _eflags = ctxt->eflags;
544 unsigned long modrm_val = 0;
545
546 memcpy(_regs, ctxt->vcpu->regs, sizeof _regs);
547
548 switch (mode) {
549 case X86EMUL_MODE_REAL:
550 case X86EMUL_MODE_PROT16:
551 op_bytes = ad_bytes = 2;
552 break;
553 case X86EMUL_MODE_PROT32:
554 op_bytes = ad_bytes = 4;
555 break;
556#ifdef CONFIG_X86_64
557 case X86EMUL_MODE_PROT64:
558 op_bytes = 4;
559 ad_bytes = 8;
560 break;
561#endif
562 default:
563 return -1;
564 }
565
566 /* Legacy prefixes. */
567 for (i = 0; i < 8; i++) {
568 switch (b = insn_fetch(u8, 1, _eip)) {
569 case 0x66: /* operand-size override */
570 op_bytes ^= 6; /* switch between 2/4 bytes */
571 break;
572 case 0x67: /* address-size override */
573 if (mode == X86EMUL_MODE_PROT64)
574 ad_bytes ^= 12; /* switch between 4/8 bytes */
575 else
576 ad_bytes ^= 6; /* switch between 2/4 bytes */
577 break;
578 case 0x2e: /* CS override */
579 override_base = &ctxt->cs_base;
580 break;
581 case 0x3e: /* DS override */
582 override_base = &ctxt->ds_base;
583 break;
584 case 0x26: /* ES override */
585 override_base = &ctxt->es_base;
586 break;
587 case 0x64: /* FS override */
588 override_base = &ctxt->fs_base;
589 break;
590 case 0x65: /* GS override */
591 override_base = &ctxt->gs_base;
592 break;
593 case 0x36: /* SS override */
594 override_base = &ctxt->ss_base;
595 break;
596 case 0xf0: /* LOCK */
597 lock_prefix = 1;
598 break;
599 case 0xf2: /* REPNE/REPNZ */
600 case 0xf3: /* REP/REPE/REPZ */
601 rep_prefix = 1;
602 break;
603 default:
604 goto done_prefixes;
605 }
606 }
607
608done_prefixes:
609
610 /* REX prefix. */
611 if ((mode == X86EMUL_MODE_PROT64) && ((b & 0xf0) == 0x40)) {
612 rex_prefix = b;
613 if (b & 8)
614 op_bytes = 8; /* REX.W */
615 modrm_reg = (b & 4) << 1; /* REX.R */
616 index_reg = (b & 2) << 2; /* REX.X */
617 modrm_rm = base_reg = (b & 1) << 3; /* REG.B */
618 b = insn_fetch(u8, 1, _eip);
619 }
620
621 /* Opcode byte(s). */
622 d = opcode_table[b];
623 if (d == 0) {
624 /* Two-byte opcode? */
625 if (b == 0x0f) {
626 twobyte = 1;
627 b = insn_fetch(u8, 1, _eip);
628 d = twobyte_table[b];
629 }
630
631 /* Unrecognised? */
632 if (d == 0)
633 goto cannot_emulate;
634 }
635
636 /* ModRM and SIB bytes. */
637 if (d & ModRM) {
638 modrm = insn_fetch(u8, 1, _eip);
639 modrm_mod |= (modrm & 0xc0) >> 6;
640 modrm_reg |= (modrm & 0x38) >> 3;
641 modrm_rm |= (modrm & 0x07);
642 modrm_ea = 0;
643 use_modrm_ea = 1;
644
645 if (modrm_mod == 3) {
646 modrm_val = *(unsigned long *)
647 decode_register(modrm_rm, _regs, d & ByteOp);
648 goto modrm_done;
649 }
650
651 if (ad_bytes == 2) {
652 unsigned bx = _regs[VCPU_REGS_RBX];
653 unsigned bp = _regs[VCPU_REGS_RBP];
654 unsigned si = _regs[VCPU_REGS_RSI];
655 unsigned di = _regs[VCPU_REGS_RDI];
656
657 /* 16-bit ModR/M decode. */
658 switch (modrm_mod) {
659 case 0:
660 if (modrm_rm == 6)
661 modrm_ea += insn_fetch(u16, 2, _eip);
662 break;
663 case 1:
664 modrm_ea += insn_fetch(s8, 1, _eip);
665 break;
666 case 2:
667 modrm_ea += insn_fetch(u16, 2, _eip);
668 break;
669 }
670 switch (modrm_rm) {
671 case 0:
672 modrm_ea += bx + si;
673 break;
674 case 1:
675 modrm_ea += bx + di;
676 break;
677 case 2:
678 modrm_ea += bp + si;
679 break;
680 case 3:
681 modrm_ea += bp + di;
682 break;
683 case 4:
684 modrm_ea += si;
685 break;
686 case 5:
687 modrm_ea += di;
688 break;
689 case 6:
690 if (modrm_mod != 0)
691 modrm_ea += bp;
692 break;
693 case 7:
694 modrm_ea += bx;
695 break;
696 }
697 if (modrm_rm == 2 || modrm_rm == 3 ||
698 (modrm_rm == 6 && modrm_mod != 0))
699 if (!override_base)
700 override_base = &ctxt->ss_base;
701 modrm_ea = (u16)modrm_ea;
702 } else {
703 /* 32/64-bit ModR/M decode. */
704 switch (modrm_rm) {
705 case 4:
706 case 12:
707 sib = insn_fetch(u8, 1, _eip);
708 index_reg |= (sib >> 3) & 7;
709 base_reg |= sib & 7;
710 scale = sib >> 6;
711
712 switch (base_reg) {
713 case 5:
714 if (modrm_mod != 0)
715 modrm_ea += _regs[base_reg];
716 else
717 modrm_ea += insn_fetch(s32, 4, _eip);
718 break;
719 default:
720 modrm_ea += _regs[base_reg];
721 }
722 switch (index_reg) {
723 case 4:
724 break;
725 default:
726 modrm_ea += _regs[index_reg] << scale;
727
728 }
729 break;
730 case 5:
731 if (modrm_mod != 0)
732 modrm_ea += _regs[modrm_rm];
733 else if (mode == X86EMUL_MODE_PROT64)
734 rip_relative = 1;
735 break;
736 default:
737 modrm_ea += _regs[modrm_rm];
738 break;
739 }
740 switch (modrm_mod) {
741 case 0:
742 if (modrm_rm == 5)
743 modrm_ea += insn_fetch(s32, 4, _eip);
744 break;
745 case 1:
746 modrm_ea += insn_fetch(s8, 1, _eip);
747 break;
748 case 2:
749 modrm_ea += insn_fetch(s32, 4, _eip);
750 break;
751 }
752 }
753 if (!override_base)
754 override_base = &ctxt->ds_base;
755 if (mode == X86EMUL_MODE_PROT64 &&
756 override_base != &ctxt->fs_base &&
757 override_base != &ctxt->gs_base)
758 override_base = NULL;
759
760 if (override_base)
761 modrm_ea += *override_base;
762
763 if (rip_relative) {
764 modrm_ea += _eip;
765 switch (d & SrcMask) {
766 case SrcImmByte:
767 modrm_ea += 1;
768 break;
769 case SrcImm:
770 if (d & ByteOp)
771 modrm_ea += 1;
772 else
773 if (op_bytes == 8)
774 modrm_ea += 4;
775 else
776 modrm_ea += op_bytes;
777 }
778 }
779 if (ad_bytes != 8)
780 modrm_ea = (u32)modrm_ea;
781 cr2 = modrm_ea;
782 modrm_done:
783 ;
784 }
785
786 /*
787 * Decode and fetch the source operand: register, memory
788 * or immediate.
789 */
790 switch (d & SrcMask) {
791 case SrcNone:
792 break;
793 case SrcReg:
794 src.type = OP_REG;
795 if (d & ByteOp) {
796 src.ptr = decode_register(modrm_reg, _regs,
797 (rex_prefix == 0));
798 src.val = src.orig_val = *(u8 *) src.ptr;
799 src.bytes = 1;
800 } else {
801 src.ptr = decode_register(modrm_reg, _regs, 0);
802 switch ((src.bytes = op_bytes)) {
803 case 2:
804 src.val = src.orig_val = *(u16 *) src.ptr;
805 break;
806 case 4:
807 src.val = src.orig_val = *(u32 *) src.ptr;
808 break;
809 case 8:
810 src.val = src.orig_val = *(u64 *) src.ptr;
811 break;
812 }
813 }
814 break;
815 case SrcMem16:
816 src.bytes = 2;
817 goto srcmem_common;
818 case SrcMem32:
819 src.bytes = 4;
820 goto srcmem_common;
821 case SrcMem:
822 src.bytes = (d & ByteOp) ? 1 : op_bytes;
823 /* Don't fetch the address for invlpg: it could be unmapped. */
824 if (twobyte && b == 0x01 && modrm_reg == 7)
825 break;
826 srcmem_common:
827 /*
828 * For instructions with a ModR/M byte, switch to register
829 * access if Mod = 3.
830 */
831 if ((d & ModRM) && modrm_mod == 3) {
832 src.type = OP_REG;
833 break;
834 }
835 src.type = OP_MEM;
836 src.ptr = (unsigned long *)cr2;
837 src.val = 0;
838 if ((rc = ops->read_emulated((unsigned long)src.ptr,
839 &src.val, src.bytes, ctxt->vcpu)) != 0)
840 goto done;
841 src.orig_val = src.val;
842 break;
843 case SrcImm:
844 src.type = OP_IMM;
845 src.ptr = (unsigned long *)_eip;
846 src.bytes = (d & ByteOp) ? 1 : op_bytes;
847 if (src.bytes == 8)
848 src.bytes = 4;
849 /* NB. Immediates are sign-extended as necessary. */
850 switch (src.bytes) {
851 case 1:
852 src.val = insn_fetch(s8, 1, _eip);
853 break;
854 case 2:
855 src.val = insn_fetch(s16, 2, _eip);
856 break;
857 case 4:
858 src.val = insn_fetch(s32, 4, _eip);
859 break;
860 }
861 break;
862 case SrcImmByte:
863 src.type = OP_IMM;
864 src.ptr = (unsigned long *)_eip;
865 src.bytes = 1;
866 src.val = insn_fetch(s8, 1, _eip);
867 break;
868 }
869
870 /* Decode and fetch the destination operand: register or memory. */
871 switch (d & DstMask) {
872 case ImplicitOps:
873 /* Special instructions do their own operand decoding. */
874 goto special_insn;
875 case DstReg:
876 dst.type = OP_REG;
877 if ((d & ByteOp)
878 && !(twobyte && (b == 0xb6 || b == 0xb7))) {
879 dst.ptr = decode_register(modrm_reg, _regs,
880 (rex_prefix == 0));
881 dst.val = *(u8 *) dst.ptr;
882 dst.bytes = 1;
883 } else {
884 dst.ptr = decode_register(modrm_reg, _regs, 0);
885 switch ((dst.bytes = op_bytes)) {
886 case 2:
887 dst.val = *(u16 *)dst.ptr;
888 break;
889 case 4:
890 dst.val = *(u32 *)dst.ptr;
891 break;
892 case 8:
893 dst.val = *(u64 *)dst.ptr;
894 break;
895 }
896 }
897 break;
898 case DstMem:
899 dst.type = OP_MEM;
900 dst.ptr = (unsigned long *)cr2;
901 dst.bytes = (d & ByteOp) ? 1 : op_bytes;
902 dst.val = 0;
903 /*
904 * For instructions with a ModR/M byte, switch to register
905 * access if Mod = 3.
906 */
907 if ((d & ModRM) && modrm_mod == 3) {
908 dst.type = OP_REG;
909 break;
910 }
911 if (d & BitOp) {
912 unsigned long mask = ~(dst.bytes * 8 - 1);
913
914 dst.ptr = (void *)dst.ptr + (src.val & mask) / 8;
915 }
916 if (!(d & Mov) && /* optimisation - avoid slow emulated read */
917 ((rc = ops->read_emulated((unsigned long)dst.ptr,
918 &dst.val, dst.bytes, ctxt->vcpu)) != 0))
919 goto done;
920 break;
921 }
922 dst.orig_val = dst.val;
923
924 if (twobyte)
925 goto twobyte_insn;
926
927 switch (b) {
928 case 0x00 ... 0x05:
929 add: /* add */
930 emulate_2op_SrcV("add", src, dst, _eflags);
931 break;
932 case 0x08 ... 0x0d:
933 or: /* or */
934 emulate_2op_SrcV("or", src, dst, _eflags);
935 break;
936 case 0x10 ... 0x15:
937 adc: /* adc */
938 emulate_2op_SrcV("adc", src, dst, _eflags);
939 break;
940 case 0x18 ... 0x1d:
941 sbb: /* sbb */
942 emulate_2op_SrcV("sbb", src, dst, _eflags);
943 break;
944 case 0x20 ... 0x23:
945 and: /* and */
946 emulate_2op_SrcV("and", src, dst, _eflags);
947 break;
948 case 0x24: /* and al imm8 */
949 dst.type = OP_REG;
950 dst.ptr = &_regs[VCPU_REGS_RAX];
951 dst.val = *(u8 *)dst.ptr;
952 dst.bytes = 1;
953 dst.orig_val = dst.val;
954 goto and;
955 case 0x25: /* and ax imm16, or eax imm32 */
956 dst.type = OP_REG;
957 dst.bytes = op_bytes;
958 dst.ptr = &_regs[VCPU_REGS_RAX];
959 if (op_bytes == 2)
960 dst.val = *(u16 *)dst.ptr;
961 else
962 dst.val = *(u32 *)dst.ptr;
963 dst.orig_val = dst.val;
964 goto and;
965 case 0x28 ... 0x2d:
966 sub: /* sub */
967 emulate_2op_SrcV("sub", src, dst, _eflags);
968 break;
969 case 0x30 ... 0x35:
970 xor: /* xor */
971 emulate_2op_SrcV("xor", src, dst, _eflags);
972 break;
973 case 0x38 ... 0x3d:
974 cmp: /* cmp */
975 emulate_2op_SrcV("cmp", src, dst, _eflags);
976 break;
977 case 0x63: /* movsxd */
978 if (mode != X86EMUL_MODE_PROT64)
979 goto cannot_emulate;
980 dst.val = (s32) src.val;
981 break;
982 case 0x80 ... 0x83: /* Grp1 */
983 switch (modrm_reg) {
984 case 0:
985 goto add;
986 case 1:
987 goto or;
988 case 2:
989 goto adc;
990 case 3:
991 goto sbb;
992 case 4:
993 goto and;
994 case 5:
995 goto sub;
996 case 6:
997 goto xor;
998 case 7:
999 goto cmp;
1000 }
1001 break;
1002 case 0x84 ... 0x85:
1003 test: /* test */
1004 emulate_2op_SrcV("test", src, dst, _eflags);
1005 break;
1006 case 0x86 ... 0x87: /* xchg */
1007 /* Write back the register source. */
1008 switch (dst.bytes) {
1009 case 1:
1010 *(u8 *) src.ptr = (u8) dst.val;
1011 break;
1012 case 2:
1013 *(u16 *) src.ptr = (u16) dst.val;
1014 break;
1015 case 4:
1016 *src.ptr = (u32) dst.val;
1017 break; /* 64b reg: zero-extend */
1018 case 8:
1019 *src.ptr = dst.val;
1020 break;
1021 }
1022 /*
1023 * Write back the memory destination with implicit LOCK
1024 * prefix.
1025 */
1026 dst.val = src.val;
1027 lock_prefix = 1;
1028 break;
1029 case 0x88 ... 0x8b: /* mov */
1030 goto mov;
1031 case 0x8d: /* lea r16/r32, m */
1032 dst.val = modrm_val;
1033 break;
1034 case 0x8f: /* pop (sole member of Grp1a) */
1035 /* 64-bit mode: POP always pops a 64-bit operand. */
1036 if (mode == X86EMUL_MODE_PROT64)
1037 dst.bytes = 8;
1038 if ((rc = ops->read_std(register_address(ctxt->ss_base,
1039 _regs[VCPU_REGS_RSP]),
1040 &dst.val, dst.bytes, ctxt->vcpu)) != 0)
1041 goto done;
1042 register_address_increment(_regs[VCPU_REGS_RSP], dst.bytes);
1043 break;
1044 case 0xa0 ... 0xa1: /* mov */
1045 dst.ptr = (unsigned long *)&_regs[VCPU_REGS_RAX];
1046 dst.val = src.val;
1047 _eip += ad_bytes; /* skip src displacement */
1048 break;
1049 case 0xa2 ... 0xa3: /* mov */
1050 dst.val = (unsigned long)_regs[VCPU_REGS_RAX];
1051 _eip += ad_bytes; /* skip dst displacement */
1052 break;
1053 case 0xc0 ... 0xc1:
1054 grp2: /* Grp2 */
1055 switch (modrm_reg) {
1056 case 0: /* rol */
1057 emulate_2op_SrcB("rol", src, dst, _eflags);
1058 break;
1059 case 1: /* ror */
1060 emulate_2op_SrcB("ror", src, dst, _eflags);
1061 break;
1062 case 2: /* rcl */
1063 emulate_2op_SrcB("rcl", src, dst, _eflags);
1064 break;
1065 case 3: /* rcr */
1066 emulate_2op_SrcB("rcr", src, dst, _eflags);
1067 break;
1068 case 4: /* sal/shl */
1069 case 6: /* sal/shl */
1070 emulate_2op_SrcB("sal", src, dst, _eflags);
1071 break;
1072 case 5: /* shr */
1073 emulate_2op_SrcB("shr", src, dst, _eflags);
1074 break;
1075 case 7: /* sar */
1076 emulate_2op_SrcB("sar", src, dst, _eflags);
1077 break;
1078 }
1079 break;
1080 case 0xc6 ... 0xc7: /* mov (sole member of Grp11) */
1081 mov:
1082 dst.val = src.val;
1083 break;
1084 case 0xd0 ... 0xd1: /* Grp2 */
1085 src.val = 1;
1086 goto grp2;
1087 case 0xd2 ... 0xd3: /* Grp2 */
1088 src.val = _regs[VCPU_REGS_RCX];
1089 goto grp2;
1090 case 0xf6 ... 0xf7: /* Grp3 */
1091 switch (modrm_reg) {
1092 case 0 ... 1: /* test */
1093 /*
1094 * Special case in Grp3: test has an immediate
1095 * source operand.
1096 */
1097 src.type = OP_IMM;
1098 src.ptr = (unsigned long *)_eip;
1099 src.bytes = (d & ByteOp) ? 1 : op_bytes;
1100 if (src.bytes == 8)
1101 src.bytes = 4;
1102 switch (src.bytes) {
1103 case 1:
1104 src.val = insn_fetch(s8, 1, _eip);
1105 break;
1106 case 2:
1107 src.val = insn_fetch(s16, 2, _eip);
1108 break;
1109 case 4:
1110 src.val = insn_fetch(s32, 4, _eip);
1111 break;
1112 }
1113 goto test;
1114 case 2: /* not */
1115 dst.val = ~dst.val;
1116 break;
1117 case 3: /* neg */
1118 emulate_1op("neg", dst, _eflags);
1119 break;
1120 default:
1121 goto cannot_emulate;
1122 }
1123 break;
1124 case 0xfe ... 0xff: /* Grp4/Grp5 */
1125 switch (modrm_reg) {
1126 case 0: /* inc */
1127 emulate_1op("inc", dst, _eflags);
1128 break;
1129 case 1: /* dec */
1130 emulate_1op("dec", dst, _eflags);
1131 break;
1132 case 4: /* jmp abs */
1133 if (b == 0xff)
1134 _eip = dst.val;
1135 else
1136 goto cannot_emulate;
1137 break;
1138 case 6: /* push */
1139 /* 64-bit mode: PUSH always pushes a 64-bit operand. */
1140 if (mode == X86EMUL_MODE_PROT64) {
1141 dst.bytes = 8;
1142 if ((rc = ops->read_std((unsigned long)dst.ptr,
1143 &dst.val, 8,
1144 ctxt->vcpu)) != 0)
1145 goto done;
1146 }
1147 register_address_increment(_regs[VCPU_REGS_RSP],
1148 -dst.bytes);
1149 if ((rc = ops->write_emulated(
1150 register_address(ctxt->ss_base,
1151 _regs[VCPU_REGS_RSP]),
1152 &dst.val, dst.bytes, ctxt->vcpu)) != 0)
1153 goto done;
1154 no_wb = 1;
1155 break;
1156 default:
1157 goto cannot_emulate;
1158 }
1159 break;
1160 }
1161
1162writeback:
1163 if (!no_wb) {
1164 switch (dst.type) {
1165 case OP_REG:
1166 /* The 4-byte case *is* correct: in 64-bit mode we zero-extend. */
1167 switch (dst.bytes) {
1168 case 1:
1169 *(u8 *)dst.ptr = (u8)dst.val;
1170 break;
1171 case 2:
1172 *(u16 *)dst.ptr = (u16)dst.val;
1173 break;
1174 case 4:
1175 *dst.ptr = (u32)dst.val;
1176 break; /* 64b: zero-ext */
1177 case 8:
1178 *dst.ptr = dst.val;
1179 break;
1180 }
1181 break;
1182 case OP_MEM:
1183 if (lock_prefix)
1184 rc = ops->cmpxchg_emulated((unsigned long)dst.
1185 ptr, &dst.orig_val,
1186 &dst.val, dst.bytes,
1187 ctxt->vcpu);
1188 else
1189 rc = ops->write_emulated((unsigned long)dst.ptr,
1190 &dst.val, dst.bytes,
1191 ctxt->vcpu);
1192 if (rc != 0)
1193 goto done;
1194 default:
1195 break;
1196 }
1197 }
1198
1199 /* Commit shadow register state. */
1200 memcpy(ctxt->vcpu->regs, _regs, sizeof _regs);
1201 ctxt->eflags = _eflags;
1202 ctxt->vcpu->rip = _eip;
1203
1204done:
1205 return (rc == X86EMUL_UNHANDLEABLE) ? -1 : 0;
1206
1207special_insn:
1208 if (twobyte)
1209 goto twobyte_special_insn;
1210 switch(b) {
1211 case 0x50 ... 0x57: /* push reg */
1212 if (op_bytes == 2)
1213 src.val = (u16) _regs[b & 0x7];
1214 else
1215 src.val = (u32) _regs[b & 0x7];
1216 dst.type = OP_MEM;
1217 dst.bytes = op_bytes;
1218 dst.val = src.val;
1219 register_address_increment(_regs[VCPU_REGS_RSP], -op_bytes);
1220 dst.ptr = (void *) register_address(
1221 ctxt->ss_base, _regs[VCPU_REGS_RSP]);
1222 break;
1223 case 0x58 ... 0x5f: /* pop reg */
1224 dst.ptr = (unsigned long *)&_regs[b & 0x7];
1225 pop_instruction:
1226 if ((rc = ops->read_std(register_address(ctxt->ss_base,
1227 _regs[VCPU_REGS_RSP]), dst.ptr, op_bytes, ctxt->vcpu))
1228 != 0)
1229 goto done;
1230
1231 register_address_increment(_regs[VCPU_REGS_RSP], op_bytes);
1232 no_wb = 1; /* Disable writeback. */
1233 break;
1234 case 0x6a: /* push imm8 */
1235 src.val = 0L;
1236 src.val = insn_fetch(s8, 1, _eip);
1237 push:
1238 dst.type = OP_MEM;
1239 dst.bytes = op_bytes;
1240 dst.val = src.val;
1241 register_address_increment(_regs[VCPU_REGS_RSP], -op_bytes);
1242 dst.ptr = (void *) register_address(ctxt->ss_base,
1243 _regs[VCPU_REGS_RSP]);
1244 break;
1245 case 0x6c: /* insb */
1246 case 0x6d: /* insw/insd */
1247 if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
1248 1, /* in */
1249 (d & ByteOp) ? 1 : op_bytes, /* size */
1250 rep_prefix ?
1251 address_mask(_regs[VCPU_REGS_RCX]) : 1, /* count */
1252 (_eflags & EFLG_DF), /* down */
1253 register_address(ctxt->es_base,
1254 _regs[VCPU_REGS_RDI]), /* address */
1255 rep_prefix,
1256 _regs[VCPU_REGS_RDX] /* port */
1257 ) == 0)
1258 return -1;
1259 return 0;
1260 case 0x6e: /* outsb */
1261 case 0x6f: /* outsw/outsd */
1262 if (kvm_emulate_pio_string(ctxt->vcpu, NULL,
1263 0, /* in */
1264 (d & ByteOp) ? 1 : op_bytes, /* size */
1265 rep_prefix ?
1266 address_mask(_regs[VCPU_REGS_RCX]) : 1, /* count */
1267 (_eflags & EFLG_DF), /* down */
1268 register_address(override_base ?
1269 *override_base : ctxt->ds_base,
1270 _regs[VCPU_REGS_RSI]), /* address */
1271 rep_prefix,
1272 _regs[VCPU_REGS_RDX] /* port */
1273 ) == 0)
1274 return -1;
1275 return 0;
1276 case 0x70 ... 0x7f: /* jcc (short) */ {
1277 int rel = insn_fetch(s8, 1, _eip);
1278
1279 if (test_cc(b, _eflags))
1280 JMP_REL(rel);
1281 break;
1282 }
1283 case 0x9c: /* pushf */
1284 src.val = (unsigned long) _eflags;
1285 goto push;
1286 case 0x9d: /* popf */
1287 dst.ptr = (unsigned long *) &_eflags;
1288 goto pop_instruction;
1289 case 0xc3: /* ret */
1290 dst.ptr = &_eip;
1291 goto pop_instruction;
1292 case 0xf4: /* hlt */
1293 ctxt->vcpu->halt_request = 1;
1294 goto done;
1295 }
1296 if (rep_prefix) {
1297 if (_regs[VCPU_REGS_RCX] == 0) {
1298 ctxt->vcpu->rip = _eip;
1299 goto done;
1300 }
1301 _regs[VCPU_REGS_RCX]--;
1302 _eip = ctxt->vcpu->rip;
1303 }
1304 switch (b) {
1305 case 0xa4 ... 0xa5: /* movs */
1306 dst.type = OP_MEM;
1307 dst.bytes = (d & ByteOp) ? 1 : op_bytes;
1308 dst.ptr = (unsigned long *)register_address(ctxt->es_base,
1309 _regs[VCPU_REGS_RDI]);
1310 if ((rc = ops->read_emulated(register_address(
1311 override_base ? *override_base : ctxt->ds_base,
1312 _regs[VCPU_REGS_RSI]), &dst.val, dst.bytes, ctxt->vcpu)) != 0)
1313 goto done;
1314 register_address_increment(_regs[VCPU_REGS_RSI],
1315 (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
1316 register_address_increment(_regs[VCPU_REGS_RDI],
1317 (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
1318 break;
1319 case 0xa6 ... 0xa7: /* cmps */
1320 DPRINTF("Urk! I don't handle CMPS.\n");
1321 goto cannot_emulate;
1322 case 0xaa ... 0xab: /* stos */
1323 dst.type = OP_MEM;
1324 dst.bytes = (d & ByteOp) ? 1 : op_bytes;
1325 dst.ptr = (unsigned long *)cr2;
1326 dst.val = _regs[VCPU_REGS_RAX];
1327 register_address_increment(_regs[VCPU_REGS_RDI],
1328 (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
1329 break;
1330 case 0xac ... 0xad: /* lods */
1331 dst.type = OP_REG;
1332 dst.bytes = (d & ByteOp) ? 1 : op_bytes;
1333 dst.ptr = (unsigned long *)&_regs[VCPU_REGS_RAX];
1334 if ((rc = ops->read_emulated(cr2, &dst.val, dst.bytes,
1335 ctxt->vcpu)) != 0)
1336 goto done;
1337 register_address_increment(_regs[VCPU_REGS_RSI],
1338 (_eflags & EFLG_DF) ? -dst.bytes : dst.bytes);
1339 break;
1340 case 0xae ... 0xaf: /* scas */
1341 DPRINTF("Urk! I don't handle SCAS.\n");
1342 goto cannot_emulate;
1343 case 0xe8: /* call (near) */ {
1344 long int rel;
1345 switch (op_bytes) {
1346 case 2:
1347 rel = insn_fetch(s16, 2, _eip);
1348 break;
1349 case 4:
1350 rel = insn_fetch(s32, 4, _eip);
1351 break;
1352 case 8:
1353 rel = insn_fetch(s64, 8, _eip);
1354 break;
1355 default:
1356 DPRINTF("Call: Invalid op_bytes\n");
1357 goto cannot_emulate;
1358 }
1359 src.val = (unsigned long) _eip;
1360 JMP_REL(rel);
1361 op_bytes = ad_bytes;
1362 goto push;
1363 }
1364 case 0xe9: /* jmp rel */
1365 case 0xeb: /* jmp rel short */
1366 JMP_REL(src.val);
1367 no_wb = 1; /* Disable writeback. */
1368 break;
1369
1370
1371 }
1372 goto writeback;
1373
1374twobyte_insn:
1375 switch (b) {
1376 case 0x01: /* lgdt, lidt, lmsw */
1377 /* Disable writeback. */
1378 no_wb = 1;
1379 switch (modrm_reg) {
1380 u16 size;
1381 unsigned long address;
1382
1383 case 2: /* lgdt */
1384 rc = read_descriptor(ctxt, ops, src.ptr,
1385 &size, &address, op_bytes);
1386 if (rc)
1387 goto done;
1388 realmode_lgdt(ctxt->vcpu, size, address);
1389 break;
1390 case 3: /* lidt */
1391 rc = read_descriptor(ctxt, ops, src.ptr,
1392 &size, &address, op_bytes);
1393 if (rc)
1394 goto done;
1395 realmode_lidt(ctxt->vcpu, size, address);
1396 break;
1397 case 4: /* smsw */
1398 if (modrm_mod != 3)
1399 goto cannot_emulate;
1400 *(u16 *)&_regs[modrm_rm]
1401 = realmode_get_cr(ctxt->vcpu, 0);
1402 break;
1403 case 6: /* lmsw */
1404 if (modrm_mod != 3)
1405 goto cannot_emulate;
1406 realmode_lmsw(ctxt->vcpu, (u16)modrm_val, &_eflags);
1407 break;
1408 case 7: /* invlpg*/
1409 emulate_invlpg(ctxt->vcpu, cr2);
1410 break;
1411 default:
1412 goto cannot_emulate;
1413 }
1414 break;
1415 case 0x21: /* mov from dr to reg */
1416 no_wb = 1;
1417 if (modrm_mod != 3)
1418 goto cannot_emulate;
1419 rc = emulator_get_dr(ctxt, modrm_reg, &_regs[modrm_rm]);
1420 break;
1421 case 0x23: /* mov from reg to dr */
1422 no_wb = 1;
1423 if (modrm_mod != 3)
1424 goto cannot_emulate;
1425 rc = emulator_set_dr(ctxt, modrm_reg, _regs[modrm_rm]);
1426 break;
1427 case 0x40 ... 0x4f: /* cmov */
1428 dst.val = dst.orig_val = src.val;
1429 no_wb = 1;
1430 /*
1431 * First, assume we're decoding an even cmov opcode
1432 * (lsb == 0).
1433 */
1434 switch ((b & 15) >> 1) {
1435 case 0: /* cmovo */
1436 no_wb = (_eflags & EFLG_OF) ? 0 : 1;
1437 break;
1438 case 1: /* cmovb/cmovc/cmovnae */
1439 no_wb = (_eflags & EFLG_CF) ? 0 : 1;
1440 break;
1441 case 2: /* cmovz/cmove */
1442 no_wb = (_eflags & EFLG_ZF) ? 0 : 1;
1443 break;
1444 case 3: /* cmovbe/cmovna */
1445 no_wb = (_eflags & (EFLG_CF | EFLG_ZF)) ? 0 : 1;
1446 break;
1447 case 4: /* cmovs */
1448 no_wb = (_eflags & EFLG_SF) ? 0 : 1;
1449 break;
1450 case 5: /* cmovp/cmovpe */
1451 no_wb = (_eflags & EFLG_PF) ? 0 : 1;
1452 break;
1453 case 7: /* cmovle/cmovng */
1454 no_wb = (_eflags & EFLG_ZF) ? 0 : 1;
1455 /* fall through */
1456 case 6: /* cmovl/cmovnge */
1457 no_wb &= (!(_eflags & EFLG_SF) !=
1458 !(_eflags & EFLG_OF)) ? 0 : 1;
1459 break;
1460 }
1461 /* Odd cmov opcodes (lsb == 1) have inverted sense. */
1462 no_wb ^= b & 1;
1463 break;
1464 case 0xa3:
1465 bt: /* bt */
1466 src.val &= (dst.bytes << 3) - 1; /* only subword offset */
1467 emulate_2op_SrcV_nobyte("bt", src, dst, _eflags);
1468 break;
1469 case 0xab:
1470 bts: /* bts */
1471 src.val &= (dst.bytes << 3) - 1; /* only subword offset */
1472 emulate_2op_SrcV_nobyte("bts", src, dst, _eflags);
1473 break;
1474 case 0xb0 ... 0xb1: /* cmpxchg */
1475 /*
1476 * Save real source value, then compare EAX against
1477 * destination.
1478 */
1479 src.orig_val = src.val;
1480 src.val = _regs[VCPU_REGS_RAX];
1481 emulate_2op_SrcV("cmp", src, dst, _eflags);
1482 if (_eflags & EFLG_ZF) {
1483 /* Success: write back to memory. */
1484 dst.val = src.orig_val;
1485 } else {
1486 /* Failure: write the value we saw to EAX. */
1487 dst.type = OP_REG;
1488 dst.ptr = (unsigned long *)&_regs[VCPU_REGS_RAX];
1489 }
1490 break;
1491 case 0xb3:
1492 btr: /* btr */
1493 src.val &= (dst.bytes << 3) - 1; /* only subword offset */
1494 emulate_2op_SrcV_nobyte("btr", src, dst, _eflags);
1495 break;
1496 case 0xb6 ... 0xb7: /* movzx */
1497 dst.bytes = op_bytes;
1498 dst.val = (d & ByteOp) ? (u8) src.val : (u16) src.val;
1499 break;
1500 case 0xba: /* Grp8 */
1501 switch (modrm_reg & 3) {
1502 case 0:
1503 goto bt;
1504 case 1:
1505 goto bts;
1506 case 2:
1507 goto btr;
1508 case 3:
1509 goto btc;
1510 }
1511 break;
1512 case 0xbb:
1513 btc: /* btc */
1514 src.val &= (dst.bytes << 3) - 1; /* only subword offset */
1515 emulate_2op_SrcV_nobyte("btc", src, dst, _eflags);
1516 break;
1517 case 0xbe ... 0xbf: /* movsx */
1518 dst.bytes = op_bytes;
1519 dst.val = (d & ByteOp) ? (s8) src.val : (s16) src.val;
1520 break;
1521 case 0xc3: /* movnti */
1522 dst.bytes = op_bytes;
1523 dst.val = (op_bytes == 4) ? (u32) src.val : (u64) src.val;
1524 break;
1525 }
1526 goto writeback;
1527
1528twobyte_special_insn:
1529 /* Disable writeback. */
1530 no_wb = 1;
1531 switch (b) {
1532 case 0x06:
1533 emulate_clts(ctxt->vcpu);
1534 break;
1535 case 0x08: /* invd */
1536 break;
1537 case 0x09: /* wbinvd */
1538 break;
1539 case 0x0d: /* GrpP (prefetch) */
1540 case 0x18: /* Grp16 (prefetch/nop) */
1541 break;
1542 case 0x20: /* mov cr, reg */
1543 if (modrm_mod != 3)
1544 goto cannot_emulate;
1545 _regs[modrm_rm] = realmode_get_cr(ctxt->vcpu, modrm_reg);
1546 break;
1547 case 0x22: /* mov reg, cr */
1548 if (modrm_mod != 3)
1549 goto cannot_emulate;
1550 realmode_set_cr(ctxt->vcpu, modrm_reg, modrm_val, &_eflags);
1551 break;
1552 case 0x30:
1553 /* wrmsr */
1554 msr_data = (u32)_regs[VCPU_REGS_RAX]
1555 | ((u64)_regs[VCPU_REGS_RDX] << 32);
1556 rc = kvm_set_msr(ctxt->vcpu, _regs[VCPU_REGS_RCX], msr_data);
1557 if (rc) {
1558 kvm_x86_ops->inject_gp(ctxt->vcpu, 0);
1559 _eip = ctxt->vcpu->rip;
1560 }
1561 rc = X86EMUL_CONTINUE;
1562 break;
1563 case 0x32:
1564 /* rdmsr */
1565 rc = kvm_get_msr(ctxt->vcpu, _regs[VCPU_REGS_RCX], &msr_data);
1566 if (rc) {
1567 kvm_x86_ops->inject_gp(ctxt->vcpu, 0);
1568 _eip = ctxt->vcpu->rip;
1569 } else {
1570 _regs[VCPU_REGS_RAX] = (u32)msr_data;
1571 _regs[VCPU_REGS_RDX] = msr_data >> 32;
1572 }
1573 rc = X86EMUL_CONTINUE;
1574 break;
1575 case 0x80 ... 0x8f: /* jnz rel, etc*/ {
1576 long int rel;
1577
1578 switch (op_bytes) {
1579 case 2:
1580 rel = insn_fetch(s16, 2, _eip);
1581 break;
1582 case 4:
1583 rel = insn_fetch(s32, 4, _eip);
1584 break;
1585 case 8:
1586 rel = insn_fetch(s64, 8, _eip);
1587 break;
1588 default:
1589 DPRINTF("jnz: Invalid op_bytes\n");
1590 goto cannot_emulate;
1591 }
1592 if (test_cc(b, _eflags))
1593 JMP_REL(rel);
1594 break;
1595 }
1596 case 0xc7: /* Grp9 (cmpxchg8b) */
1597 {
1598 u64 old, new;
1599 if ((rc = ops->read_emulated(cr2, &old, 8, ctxt->vcpu))
1600 != 0)
1601 goto done;
1602 if (((u32) (old >> 0) != (u32) _regs[VCPU_REGS_RAX]) ||
1603 ((u32) (old >> 32) != (u32) _regs[VCPU_REGS_RDX])) {
1604 _regs[VCPU_REGS_RAX] = (u32) (old >> 0);
1605 _regs[VCPU_REGS_RDX] = (u32) (old >> 32);
1606 _eflags &= ~EFLG_ZF;
1607 } else {
1608 new = ((u64)_regs[VCPU_REGS_RCX] << 32)
1609 | (u32) _regs[VCPU_REGS_RBX];
1610 if ((rc = ops->cmpxchg_emulated(cr2, &old,
1611 &new, 8, ctxt->vcpu)) != 0)
1612 goto done;
1613 _eflags |= EFLG_ZF;
1614 }
1615 break;
1616 }
1617 }
1618 goto writeback;
1619
1620cannot_emulate:
1621 DPRINTF("Cannot emulate %02x\n", b);
1622 return -1;
1623}
1624
1625#ifdef __XEN__
1626
1627#include <asm/mm.h>
1628#include <asm/uaccess.h>
1629
1630int
1631x86_emulate_read_std(unsigned long addr,
1632 unsigned long *val,
1633 unsigned int bytes, struct x86_emulate_ctxt *ctxt)
1634{
1635 unsigned int rc;
1636
1637 *val = 0;
1638
1639 if ((rc = copy_from_user((void *)val, (void *)addr, bytes)) != 0) {
1640 propagate_page_fault(addr + bytes - rc, 0); /* read fault */
1641 return X86EMUL_PROPAGATE_FAULT;
1642 }
1643
1644 return X86EMUL_CONTINUE;
1645}
1646
1647int
1648x86_emulate_write_std(unsigned long addr,
1649 unsigned long val,
1650 unsigned int bytes, struct x86_emulate_ctxt *ctxt)
1651{
1652 unsigned int rc;
1653
1654 if ((rc = copy_to_user((void *)addr, (void *)&val, bytes)) != 0) {
1655 propagate_page_fault(addr + bytes - rc, PGERR_write_access);
1656 return X86EMUL_PROPAGATE_FAULT;
1657 }
1658
1659 return X86EMUL_CONTINUE;
1660}
1661
1662#endif
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-10 21:41:27 -0400