xref: /qemu/target/i386/emulate/x86_emu.c (revision 7abf0d95ac6437b38437ad75711c081363995285)
1 /*
2  * Copyright (C) 2016 Veertu Inc,
3  * Copyright (C) 2017 Google Inc,
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this program; if not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 /////////////////////////////////////////////////////////////////////////
20 //
21 //  Copyright (C) 2001-2012  The Bochs Project
22 //
23 //  This library is free software; you can redistribute it and/or
24 //  modify it under the terms of the GNU Lesser General Public
25 //  License as published by the Free Software Foundation; either
26 //  version 2.1 of the License, or (at your option) any later version.
27 //
28 //  This library is distributed in the hope that it will be useful,
29 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
30 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
31 //  Lesser General Public License for more details.
32 //
33 //  You should have received a copy of the GNU Lesser General Public
34 //  License along with this library; if not, write to the Free Software
35 //  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
36 /////////////////////////////////////////////////////////////////////////
37 
38 #include "qemu/osdep.h"
39 #include "panic.h"
40 #include "x86_decode.h"
41 #include "x86.h"
42 #include "x86_emu.h"
43 #include "x86_flags.h"
44 
45 #define EXEC_2OP_FLAGS_CMD(env, decode, cmd, FLAGS_FUNC, save_res) \
46 {                                                       \
47     fetch_operands(env, decode, 2, true, true, false);  \
48     switch (decode->operand_size) {                     \
49     case 1:                                         \
50     {                                               \
51         uint8_t v1 = (uint8_t)decode->op[0].val;    \
52         uint8_t v2 = (uint8_t)decode->op[1].val;    \
53         uint8_t diff = v1 cmd v2;                   \
54         if (save_res) {                              \
55             write_val_ext(env, decode->op[0].ptr, diff, 1);  \
56         } \
57         FLAGS_FUNC##8(env, v1, v2, diff);           \
58         break;                                      \
59     }                                               \
60     case 2:                                        \
61     {                                               \
62         uint16_t v1 = (uint16_t)decode->op[0].val;  \
63         uint16_t v2 = (uint16_t)decode->op[1].val;  \
64         uint16_t diff = v1 cmd v2;                  \
65         if (save_res) {                              \
66             write_val_ext(env, decode->op[0].ptr, diff, 2); \
67         } \
68         FLAGS_FUNC##16(env, v1, v2, diff);          \
69         break;                                      \
70     }                                               \
71     case 4:                                        \
72     {                                               \
73         uint32_t v1 = (uint32_t)decode->op[0].val;  \
74         uint32_t v2 = (uint32_t)decode->op[1].val;  \
75         uint32_t diff = v1 cmd v2;                  \
76         if (save_res) {                              \
77             write_val_ext(env, decode->op[0].ptr, diff, 4); \
78         } \
79         FLAGS_FUNC##32(env, v1, v2, diff);          \
80         break;                                      \
81     }                                               \
82     default:                                        \
83         VM_PANIC("bad size\n");                    \
84     }                                                   \
85 }                                                       \
86 
87 target_ulong read_reg(CPUX86State *env, int reg, int size)
88 {
89     switch (size) {
90     case 1:
91         return x86_reg(env, reg)->lx;
92     case 2:
93         return x86_reg(env, reg)->rx;
94     case 4:
95         return x86_reg(env, reg)->erx;
96     case 8:
97         return x86_reg(env, reg)->rrx;
98     default:
99         abort();
100     }
101     return 0;
102 }
103 
104 void write_reg(CPUX86State *env, int reg, target_ulong val, int size)
105 {
106     switch (size) {
107     case 1:
108         x86_reg(env, reg)->lx = val;
109         break;
110     case 2:
111         x86_reg(env, reg)->rx = val;
112         break;
113     case 4:
114         x86_reg(env, reg)->rrx = (uint32_t)val;
115         break;
116     case 8:
117         x86_reg(env, reg)->rrx = val;
118         break;
119     default:
120         abort();
121     }
122 }
123 
124 target_ulong read_val_from_reg(target_ulong reg_ptr, int size)
125 {
126     target_ulong val;
127 
128     switch (size) {
129     case 1:
130         val = *(uint8_t *)reg_ptr;
131         break;
132     case 2:
133         val = *(uint16_t *)reg_ptr;
134         break;
135     case 4:
136         val = *(uint32_t *)reg_ptr;
137         break;
138     case 8:
139         val = *(uint64_t *)reg_ptr;
140         break;
141     default:
142         abort();
143     }
144     return val;
145 }
146 
147 void write_val_to_reg(target_ulong reg_ptr, target_ulong val, int size)
148 {
149     switch (size) {
150     case 1:
151         *(uint8_t *)reg_ptr = val;
152         break;
153     case 2:
154         *(uint16_t *)reg_ptr = val;
155         break;
156     case 4:
157         *(uint64_t *)reg_ptr = (uint32_t)val;
158         break;
159     case 8:
160         *(uint64_t *)reg_ptr = val;
161         break;
162     default:
163         abort();
164     }
165 }
166 
167 static bool is_host_reg(CPUX86State *env, target_ulong ptr)
168 {
169     return (ptr - (target_ulong)&env->regs[0]) < sizeof(env->regs);
170 }
171 
172 void write_val_ext(CPUX86State *env, target_ulong ptr, target_ulong val, int size)
173 {
174     if (is_host_reg(env, ptr)) {
175         write_val_to_reg(ptr, val, size);
176         return;
177     }
178     emul_ops->write_mem(env_cpu(env), &val, ptr, size);
179 }
180 
181 uint8_t *read_mmio(CPUX86State *env, target_ulong ptr, int bytes)
182 {
183     emul_ops->read_mem(env_cpu(env), env->emu_mmio_buf, ptr, bytes);
184     return env->emu_mmio_buf;
185 }
186 
187 
188 target_ulong read_val_ext(CPUX86State *env, target_ulong ptr, int size)
189 {
190     target_ulong val;
191     uint8_t *mmio_ptr;
192 
193     if (is_host_reg(env, ptr)) {
194         return read_val_from_reg(ptr, size);
195     }
196 
197     mmio_ptr = read_mmio(env, ptr, size);
198     switch (size) {
199     case 1:
200         val = *(uint8_t *)mmio_ptr;
201         break;
202     case 2:
203         val = *(uint16_t *)mmio_ptr;
204         break;
205     case 4:
206         val = *(uint32_t *)mmio_ptr;
207         break;
208     case 8:
209         val = *(uint64_t *)mmio_ptr;
210         break;
211     default:
212         VM_PANIC("bad size\n");
213         break;
214     }
215     return val;
216 }
217 
218 static void fetch_operands(CPUX86State *env, struct x86_decode *decode,
219                            int n, bool val_op0, bool val_op1, bool val_op2)
220 {
221     int i;
222     bool calc_val[3] = {val_op0, val_op1, val_op2};
223 
224     for (i = 0; i < n; i++) {
225         switch (decode->op[i].type) {
226         case X86_VAR_IMMEDIATE:
227             break;
228         case X86_VAR_REG:
229             VM_PANIC_ON(!decode->op[i].ptr);
230             if (calc_val[i]) {
231                 decode->op[i].val = read_val_from_reg(decode->op[i].ptr,
232                                                       decode->operand_size);
233             }
234             break;
235         case X86_VAR_RM:
236             calc_modrm_operand(env, decode, &decode->op[i]);
237             if (calc_val[i]) {
238                 decode->op[i].val = read_val_ext(env, decode->op[i].ptr,
239                                                  decode->operand_size);
240             }
241             break;
242         case X86_VAR_OFFSET:
243             decode->op[i].ptr = decode_linear_addr(env, decode,
244                                                    decode->op[i].ptr,
245                                                    R_DS);
246             if (calc_val[i]) {
247                 decode->op[i].val = read_val_ext(env, decode->op[i].ptr,
248                                                  decode->operand_size);
249             }
250             break;
251         default:
252             break;
253         }
254     }
255 }
256 
257 static void exec_mov(CPUX86State *env, struct x86_decode *decode)
258 {
259     fetch_operands(env, decode, 2, false, true, false);
260     write_val_ext(env, decode->op[0].ptr, decode->op[1].val,
261                   decode->operand_size);
262 
263     env->eip += decode->len;
264 }
265 
266 static void exec_add(CPUX86State *env, struct x86_decode *decode)
267 {
268     EXEC_2OP_FLAGS_CMD(env, decode, +, SET_FLAGS_OSZAPC_ADD, true);
269     env->eip += decode->len;
270 }
271 
272 static void exec_or(CPUX86State *env, struct x86_decode *decode)
273 {
274     EXEC_2OP_FLAGS_CMD(env, decode, |, SET_FLAGS_OSZAPC_LOGIC, true);
275     env->eip += decode->len;
276 }
277 
278 static void exec_adc(CPUX86State *env, struct x86_decode *decode)
279 {
280     EXEC_2OP_FLAGS_CMD(env, decode, +get_CF(env)+, SET_FLAGS_OSZAPC_ADD, true);
281     env->eip += decode->len;
282 }
283 
284 static void exec_sbb(CPUX86State *env, struct x86_decode *decode)
285 {
286     EXEC_2OP_FLAGS_CMD(env, decode, -get_CF(env)-, SET_FLAGS_OSZAPC_SUB, true);
287     env->eip += decode->len;
288 }
289 
290 static void exec_and(CPUX86State *env, struct x86_decode *decode)
291 {
292     EXEC_2OP_FLAGS_CMD(env, decode, &, SET_FLAGS_OSZAPC_LOGIC, true);
293     env->eip += decode->len;
294 }
295 
296 static void exec_sub(CPUX86State *env, struct x86_decode *decode)
297 {
298     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, true);
299     env->eip += decode->len;
300 }
301 
302 static void exec_xor(CPUX86State *env, struct x86_decode *decode)
303 {
304     EXEC_2OP_FLAGS_CMD(env, decode, ^, SET_FLAGS_OSZAPC_LOGIC, true);
305     env->eip += decode->len;
306 }
307 
308 static void exec_neg(CPUX86State *env, struct x86_decode *decode)
309 {
310     /*EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);*/
311     int32_t val;
312     fetch_operands(env, decode, 2, true, true, false);
313 
314     val = 0 - sign(decode->op[1].val, decode->operand_size);
315     write_val_ext(env, decode->op[1].ptr, val, decode->operand_size);
316 
317     if (4 == decode->operand_size) {
318         SET_FLAGS_OSZAPC_SUB32(env, 0, 0 - val, val);
319     } else if (2 == decode->operand_size) {
320         SET_FLAGS_OSZAPC_SUB16(env, 0, 0 - val, val);
321     } else if (1 == decode->operand_size) {
322         SET_FLAGS_OSZAPC_SUB8(env, 0, 0 - val, val);
323     } else {
324         VM_PANIC("bad op size\n");
325     }
326 
327     /*lflags_to_rflags(env);*/
328     env->eip += decode->len;
329 }
330 
331 static void exec_cmp(CPUX86State *env, struct x86_decode *decode)
332 {
333     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);
334     env->eip += decode->len;
335 }
336 
337 static void exec_inc(CPUX86State *env, struct x86_decode *decode)
338 {
339     decode->op[1].type = X86_VAR_IMMEDIATE;
340     decode->op[1].val = 0;
341 
342     EXEC_2OP_FLAGS_CMD(env, decode, +1+, SET_FLAGS_OSZAP_ADD, true);
343 
344     env->eip += decode->len;
345 }
346 
347 static void exec_dec(CPUX86State *env, struct x86_decode *decode)
348 {
349     decode->op[1].type = X86_VAR_IMMEDIATE;
350     decode->op[1].val = 0;
351 
352     EXEC_2OP_FLAGS_CMD(env, decode, -1-, SET_FLAGS_OSZAP_SUB, true);
353     env->eip += decode->len;
354 }
355 
356 static void exec_tst(CPUX86State *env, struct x86_decode *decode)
357 {
358     EXEC_2OP_FLAGS_CMD(env, decode, &, SET_FLAGS_OSZAPC_LOGIC, false);
359     env->eip += decode->len;
360 }
361 
362 static void exec_not(CPUX86State *env, struct x86_decode *decode)
363 {
364     fetch_operands(env, decode, 1, true, false, false);
365 
366     write_val_ext(env, decode->op[0].ptr, ~decode->op[0].val,
367                   decode->operand_size);
368     env->eip += decode->len;
369 }
370 
371 void exec_movzx(CPUX86State *env, struct x86_decode *decode)
372 {
373     int src_op_size;
374     int op_size = decode->operand_size;
375 
376     fetch_operands(env, decode, 1, false, false, false);
377 
378     if (0xb6 == decode->opcode[1]) {
379         src_op_size = 1;
380     } else {
381         src_op_size = 2;
382     }
383     decode->operand_size = src_op_size;
384     calc_modrm_operand(env, decode, &decode->op[1]);
385     decode->op[1].val = read_val_ext(env, decode->op[1].ptr, src_op_size);
386     write_val_ext(env, decode->op[0].ptr, decode->op[1].val, op_size);
387 
388     env->eip += decode->len;
389 }
390 
391 static void exec_out(CPUX86State *env, struct x86_decode *decode)
392 {
393     switch (decode->opcode[0]) {
394     case 0xe6:
395         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &AL(env), 1, 1, 1);
396         break;
397     case 0xe7:
398         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &RAX(env), 1,
399                             decode->operand_size, 1);
400         break;
401     case 0xee:
402         emul_ops->handle_io(env_cpu(env), DX(env), &AL(env), 1, 1, 1);
403         break;
404     case 0xef:
405         emul_ops->handle_io(env_cpu(env), DX(env), &RAX(env), 1,
406                             decode->operand_size, 1);
407         break;
408     default:
409         VM_PANIC("Bad out opcode\n");
410         break;
411     }
412     env->eip += decode->len;
413 }
414 
415 static void exec_in(CPUX86State *env, struct x86_decode *decode)
416 {
417     target_ulong val = 0;
418     switch (decode->opcode[0]) {
419     case 0xe4:
420         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &AL(env), 0, 1, 1);
421         break;
422     case 0xe5:
423         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &val, 0,
424                       decode->operand_size, 1);
425         if (decode->operand_size == 2) {
426             AX(env) = val;
427         } else {
428             RAX(env) = (uint32_t)val;
429         }
430         break;
431     case 0xec:
432         emul_ops->handle_io(env_cpu(env), DX(env), &AL(env), 0, 1, 1);
433         break;
434     case 0xed:
435         emul_ops->handle_io(env_cpu(env), DX(env), &val, 0,
436                             decode->operand_size, 1);
437         if (decode->operand_size == 2) {
438             AX(env) = val;
439         } else {
440             RAX(env) = (uint32_t)val;
441         }
442 
443         break;
444     default:
445         VM_PANIC("Bad in opcode\n");
446         break;
447     }
448 
449     env->eip += decode->len;
450 }
451 
452 static inline void string_increment_reg(CPUX86State *env, int reg,
453                                         struct x86_decode *decode)
454 {
455     target_ulong val = read_reg(env, reg, decode->addressing_size);
456     if (env->eflags & DF_MASK) {
457         val -= decode->operand_size;
458     } else {
459         val += decode->operand_size;
460     }
461     write_reg(env, reg, val, decode->addressing_size);
462 }
463 
464 static inline void string_rep(CPUX86State *env, struct x86_decode *decode,
465                               void (*func)(CPUX86State *env,
466                                            struct x86_decode *ins), int rep)
467 {
468     target_ulong rcx = read_reg(env, R_ECX, decode->addressing_size);
469     while (rcx--) {
470         func(env, decode);
471         write_reg(env, R_ECX, rcx, decode->addressing_size);
472         if ((PREFIX_REP == rep) && !get_ZF(env)) {
473             break;
474         }
475         if ((PREFIX_REPN == rep) && get_ZF(env)) {
476             break;
477         }
478     }
479 }
480 
481 static void exec_ins_single(CPUX86State *env, struct x86_decode *decode)
482 {
483     target_ulong addr = linear_addr_size(env_cpu(env), RDI(env),
484                                          decode->addressing_size, R_ES);
485 
486     emul_ops->handle_io(env_cpu(env), DX(env), env->emu_mmio_buf, 0,
487                         decode->operand_size, 1);
488     emul_ops->write_mem(env_cpu(env), env->emu_mmio_buf, addr,
489                         decode->operand_size);
490 
491     string_increment_reg(env, R_EDI, decode);
492 }
493 
494 static void exec_ins(CPUX86State *env, struct x86_decode *decode)
495 {
496     if (decode->rep) {
497         string_rep(env, decode, exec_ins_single, 0);
498     } else {
499         exec_ins_single(env, decode);
500     }
501 
502     env->eip += decode->len;
503 }
504 
505 static void exec_outs_single(CPUX86State *env, struct x86_decode *decode)
506 {
507     target_ulong addr = decode_linear_addr(env, decode, RSI(env), R_DS);
508 
509     emul_ops->read_mem(env_cpu(env), env->emu_mmio_buf, addr,
510                        decode->operand_size);
511     emul_ops->handle_io(env_cpu(env), DX(env), env->emu_mmio_buf, 1,
512                         decode->operand_size, 1);
513 
514     string_increment_reg(env, R_ESI, decode);
515 }
516 
517 static void exec_outs(CPUX86State *env, struct x86_decode *decode)
518 {
519     if (decode->rep) {
520         string_rep(env, decode, exec_outs_single, 0);
521     } else {
522         exec_outs_single(env, decode);
523     }
524 
525     env->eip += decode->len;
526 }
527 
528 static void exec_movs_single(CPUX86State *env, struct x86_decode *decode)
529 {
530     target_ulong src_addr;
531     target_ulong dst_addr;
532     target_ulong val;
533 
534     src_addr = decode_linear_addr(env, decode, RSI(env), R_DS);
535     dst_addr = linear_addr_size(env_cpu(env), RDI(env),
536                                 decode->addressing_size, R_ES);
537 
538     val = read_val_ext(env, src_addr, decode->operand_size);
539     write_val_ext(env, dst_addr, val, decode->operand_size);
540 
541     string_increment_reg(env, R_ESI, decode);
542     string_increment_reg(env, R_EDI, decode);
543 }
544 
545 static void exec_movs(CPUX86State *env, struct x86_decode *decode)
546 {
547     if (decode->rep) {
548         string_rep(env, decode, exec_movs_single, 0);
549     } else {
550         exec_movs_single(env, decode);
551     }
552 
553     env->eip += decode->len;
554 }
555 
556 static void exec_cmps_single(CPUX86State *env, struct x86_decode *decode)
557 {
558     target_ulong src_addr;
559     target_ulong dst_addr;
560 
561     src_addr = decode_linear_addr(env, decode, RSI(env), R_DS);
562     dst_addr = linear_addr_size(env_cpu(env), RDI(env),
563                                 decode->addressing_size, R_ES);
564 
565     decode->op[0].type = X86_VAR_IMMEDIATE;
566     decode->op[0].val = read_val_ext(env, src_addr, decode->operand_size);
567     decode->op[1].type = X86_VAR_IMMEDIATE;
568     decode->op[1].val = read_val_ext(env, dst_addr, decode->operand_size);
569 
570     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);
571 
572     string_increment_reg(env, R_ESI, decode);
573     string_increment_reg(env, R_EDI, decode);
574 }
575 
576 static void exec_cmps(CPUX86State *env, struct x86_decode *decode)
577 {
578     if (decode->rep) {
579         string_rep(env, decode, exec_cmps_single, decode->rep);
580     } else {
581         exec_cmps_single(env, decode);
582     }
583     env->eip += decode->len;
584 }
585 
586 
587 static void exec_stos_single(CPUX86State *env, struct x86_decode *decode)
588 {
589     target_ulong addr;
590     target_ulong val;
591 
592     addr = linear_addr_size(env_cpu(env), RDI(env),
593                             decode->addressing_size, R_ES);
594     val = read_reg(env, R_EAX, decode->operand_size);
595     emul_ops->write_mem(env_cpu(env), &val, addr, decode->operand_size);
596 
597     string_increment_reg(env, R_EDI, decode);
598 }
599 
600 
601 static void exec_stos(CPUX86State *env, struct x86_decode *decode)
602 {
603     if (decode->rep) {
604         string_rep(env, decode, exec_stos_single, 0);
605     } else {
606         exec_stos_single(env, decode);
607     }
608 
609     env->eip += decode->len;
610 }
611 
612 static void exec_scas_single(CPUX86State *env, struct x86_decode *decode)
613 {
614     target_ulong addr;
615 
616     addr = linear_addr_size(env_cpu(env), RDI(env),
617                             decode->addressing_size, R_ES);
618     decode->op[1].type = X86_VAR_IMMEDIATE;
619     emul_ops->read_mem(env_cpu(env), &decode->op[1].val, addr, decode->operand_size);
620 
621     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);
622     string_increment_reg(env, R_EDI, decode);
623 }
624 
625 static void exec_scas(CPUX86State *env, struct x86_decode *decode)
626 {
627     decode->op[0].type = X86_VAR_REG;
628     decode->op[0].reg = R_EAX;
629     if (decode->rep) {
630         string_rep(env, decode, exec_scas_single, decode->rep);
631     } else {
632         exec_scas_single(env, decode);
633     }
634 
635     env->eip += decode->len;
636 }
637 
638 static void exec_lods_single(CPUX86State *env, struct x86_decode *decode)
639 {
640     target_ulong addr;
641     target_ulong val = 0;
642 
643     addr = decode_linear_addr(env, decode, RSI(env), R_DS);
644     emul_ops->read_mem(env_cpu(env), &val, addr,  decode->operand_size);
645     write_reg(env, R_EAX, val, decode->operand_size);
646 
647     string_increment_reg(env, R_ESI, decode);
648 }
649 
650 static void exec_lods(CPUX86State *env, struct x86_decode *decode)
651 {
652     if (decode->rep) {
653         string_rep(env, decode, exec_lods_single, 0);
654     } else {
655         exec_lods_single(env, decode);
656     }
657 
658     env->eip += decode->len;
659 }
660 
661 void x86_emul_raise_exception(CPUX86State *env, int exception_index, int error_code)
662 {
663     env->exception_nr = exception_index;
664     env->error_code = error_code;
665     env->has_error_code = true;
666     env->exception_injected = 1;
667 }
668 
669 static void exec_rdmsr(CPUX86State *env, struct x86_decode *decode)
670 {
671     emul_ops->simulate_rdmsr(env_cpu(env));
672     env->eip += decode->len;
673 }
674 
675 static void exec_wrmsr(CPUX86State *env, struct x86_decode *decode)
676 {
677     emul_ops->simulate_wrmsr(env_cpu(env));
678     env->eip += decode->len;
679 }
680 
681 /*
682  * flag:
683  * 0 - bt, 1 - btc, 2 - bts, 3 - btr
684  */
685 static void do_bt(CPUX86State *env, struct x86_decode *decode, int flag)
686 {
687     int32_t displacement;
688     uint8_t index;
689     bool cf;
690     int mask = (4 == decode->operand_size) ? 0x1f : 0xf;
691 
692     VM_PANIC_ON(decode->rex.rex);
693 
694     fetch_operands(env, decode, 2, false, true, false);
695     index = decode->op[1].val & mask;
696 
697     if (decode->op[0].type != X86_VAR_REG) {
698         if (4 == decode->operand_size) {
699             displacement = ((int32_t) (decode->op[1].val & 0xffffffe0)) / 32;
700             decode->op[0].ptr += 4 * displacement;
701         } else if (2 == decode->operand_size) {
702             displacement = ((int16_t) (decode->op[1].val & 0xfff0)) / 16;
703             decode->op[0].ptr += 2 * displacement;
704         } else {
705             VM_PANIC("bt 64bit\n");
706         }
707     }
708     decode->op[0].val = read_val_ext(env, decode->op[0].ptr,
709                                      decode->operand_size);
710     cf = (decode->op[0].val >> index) & 0x01;
711 
712     switch (flag) {
713     case 0:
714         set_CF(env, cf);
715         return;
716     case 1:
717         decode->op[0].val ^= (1u << index);
718         break;
719     case 2:
720         decode->op[0].val |= (1u << index);
721         break;
722     case 3:
723         decode->op[0].val &= ~(1u << index);
724         break;
725     }
726     write_val_ext(env, decode->op[0].ptr, decode->op[0].val,
727                   decode->operand_size);
728     set_CF(env, cf);
729 }
730 
731 static void exec_bt(CPUX86State *env, struct x86_decode *decode)
732 {
733     do_bt(env, decode, 0);
734     env->eip += decode->len;
735 }
736 
737 static void exec_btc(CPUX86State *env, struct x86_decode *decode)
738 {
739     do_bt(env, decode, 1);
740     env->eip += decode->len;
741 }
742 
743 static void exec_btr(CPUX86State *env, struct x86_decode *decode)
744 {
745     do_bt(env, decode, 3);
746     env->eip += decode->len;
747 }
748 
749 static void exec_bts(CPUX86State *env, struct x86_decode *decode)
750 {
751     do_bt(env, decode, 2);
752     env->eip += decode->len;
753 }
754 
755 void exec_shl(CPUX86State *env, struct x86_decode *decode)
756 {
757     uint8_t count;
758     int of = 0, cf = 0;
759 
760     fetch_operands(env, decode, 2, true, true, false);
761 
762     count = decode->op[1].val;
763     count &= 0x1f;      /* count is masked to 5 bits*/
764     if (!count) {
765         goto exit;
766     }
767 
768     switch (decode->operand_size) {
769     case 1:
770     {
771         uint8_t res = 0;
772         if (count <= 8) {
773             res = (decode->op[0].val << count);
774             cf = (decode->op[0].val >> (8 - count)) & 0x1;
775             of = cf ^ (res >> 7);
776         }
777 
778         write_val_ext(env, decode->op[0].ptr, res, 1);
779         SET_FLAGS_OSZAPC_LOGIC8(env, 0, 0, res);
780         SET_FLAGS_OxxxxC(env, of, cf);
781         break;
782     }
783     case 2:
784     {
785         uint16_t res = 0;
786 
787         /* from bochs */
788         if (count <= 16) {
789             res = (decode->op[0].val << count);
790             cf = (decode->op[0].val >> (16 - count)) & 0x1;
791             of = cf ^ (res >> 15); /* of = cf ^ result15 */
792         }
793 
794         write_val_ext(env, decode->op[0].ptr, res, 2);
795         SET_FLAGS_OSZAPC_LOGIC16(env, 0, 0, res);
796         SET_FLAGS_OxxxxC(env, of, cf);
797         break;
798     }
799     case 4:
800     {
801         uint32_t res = decode->op[0].val << count;
802 
803         write_val_ext(env, decode->op[0].ptr, res, 4);
804         SET_FLAGS_OSZAPC_LOGIC32(env, 0, 0, res);
805         cf = (decode->op[0].val >> (32 - count)) & 0x1;
806         of = cf ^ (res >> 31); /* of = cf ^ result31 */
807         SET_FLAGS_OxxxxC(env, of, cf);
808         break;
809     }
810     default:
811         abort();
812     }
813 
814 exit:
815     /* lflags_to_rflags(env); */
816     env->eip += decode->len;
817 }
818 
819 void exec_movsx(CPUX86State *env, struct x86_decode *decode)
820 {
821     int src_op_size;
822     int op_size = decode->operand_size;
823 
824     fetch_operands(env, decode, 2, false, false, false);
825 
826     if (0xbe == decode->opcode[1]) {
827         src_op_size = 1;
828     } else {
829         src_op_size = 2;
830     }
831 
832     decode->operand_size = src_op_size;
833     calc_modrm_operand(env, decode, &decode->op[1]);
834     decode->op[1].val = sign(read_val_ext(env, decode->op[1].ptr, src_op_size),
835                              src_op_size);
836 
837     write_val_ext(env, decode->op[0].ptr, decode->op[1].val, op_size);
838 
839     env->eip += decode->len;
840 }
841 
842 void exec_ror(CPUX86State *env, struct x86_decode *decode)
843 {
844     uint8_t count;
845 
846     fetch_operands(env, decode, 2, true, true, false);
847     count = decode->op[1].val;
848 
849     switch (decode->operand_size) {
850     case 1:
851     {
852         uint32_t bit6, bit7;
853         uint8_t res;
854 
855         if ((count & 0x07) == 0) {
856             if (count & 0x18) {
857                 bit6 = ((uint8_t)decode->op[0].val >> 6) & 1;
858                 bit7 = ((uint8_t)decode->op[0].val >> 7) & 1;
859                 SET_FLAGS_OxxxxC(env, bit6 ^ bit7, bit7);
860              }
861         } else {
862             count &= 0x7; /* use only bottom 3 bits */
863             res = ((uint8_t)decode->op[0].val >> count) |
864                    ((uint8_t)decode->op[0].val << (8 - count));
865             write_val_ext(env, decode->op[0].ptr, res, 1);
866             bit6 = (res >> 6) & 1;
867             bit7 = (res >> 7) & 1;
868             /* set eflags: ROR count affects the following flags: C, O */
869             SET_FLAGS_OxxxxC(env, bit6 ^ bit7, bit7);
870         }
871         break;
872     }
873     case 2:
874     {
875         uint32_t bit14, bit15;
876         uint16_t res;
877 
878         if ((count & 0x0f) == 0) {
879             if (count & 0x10) {
880                 bit14 = ((uint16_t)decode->op[0].val >> 14) & 1;
881                 bit15 = ((uint16_t)decode->op[0].val >> 15) & 1;
882                 /* of = result14 ^ result15 */
883                 SET_FLAGS_OxxxxC(env, bit14 ^ bit15, bit15);
884             }
885         } else {
886             count &= 0x0f;  /* use only 4 LSB's */
887             res = ((uint16_t)decode->op[0].val >> count) |
888                    ((uint16_t)decode->op[0].val << (16 - count));
889             write_val_ext(env, decode->op[0].ptr, res, 2);
890 
891             bit14 = (res >> 14) & 1;
892             bit15 = (res >> 15) & 1;
893             /* of = result14 ^ result15 */
894             SET_FLAGS_OxxxxC(env, bit14 ^ bit15, bit15);
895         }
896         break;
897     }
898     case 4:
899     {
900         uint32_t bit31, bit30;
901         uint32_t res;
902 
903         count &= 0x1f;
904         if (count) {
905             res = ((uint32_t)decode->op[0].val >> count) |
906                    ((uint32_t)decode->op[0].val << (32 - count));
907             write_val_ext(env, decode->op[0].ptr, res, 4);
908 
909             bit31 = (res >> 31) & 1;
910             bit30 = (res >> 30) & 1;
911             /* of = result30 ^ result31 */
912             SET_FLAGS_OxxxxC(env, bit30 ^ bit31, bit31);
913         }
914         break;
915         }
916     }
917     env->eip += decode->len;
918 }
919 
920 void exec_rol(CPUX86State *env, struct x86_decode *decode)
921 {
922     uint8_t count;
923 
924     fetch_operands(env, decode, 2, true, true, false);
925     count = decode->op[1].val;
926 
927     switch (decode->operand_size) {
928     case 1:
929     {
930         uint32_t bit0, bit7;
931         uint8_t res;
932 
933         if ((count & 0x07) == 0) {
934             if (count & 0x18) {
935                 bit0 = ((uint8_t)decode->op[0].val & 1);
936                 bit7 = ((uint8_t)decode->op[0].val >> 7);
937                 SET_FLAGS_OxxxxC(env, bit0 ^ bit7, bit0);
938             }
939         }  else {
940             count &= 0x7; /* use only lowest 3 bits */
941             res = ((uint8_t)decode->op[0].val << count) |
942                    ((uint8_t)decode->op[0].val >> (8 - count));
943 
944             write_val_ext(env, decode->op[0].ptr, res, 1);
945             /* set eflags:
946              * ROL count affects the following flags: C, O
947              */
948             bit0 = (res &  1);
949             bit7 = (res >> 7);
950             SET_FLAGS_OxxxxC(env, bit0 ^ bit7, bit0);
951         }
952         break;
953     }
954     case 2:
955     {
956         uint32_t bit0, bit15;
957         uint16_t res;
958 
959         if ((count & 0x0f) == 0) {
960             if (count & 0x10) {
961                 bit0  = ((uint16_t)decode->op[0].val & 0x1);
962                 bit15 = ((uint16_t)decode->op[0].val >> 15);
963                 /* of = cf ^ result15 */
964                 SET_FLAGS_OxxxxC(env, bit0 ^ bit15, bit0);
965             }
966         } else {
967             count &= 0x0f; /* only use bottom 4 bits */
968             res = ((uint16_t)decode->op[0].val << count) |
969                    ((uint16_t)decode->op[0].val >> (16 - count));
970 
971             write_val_ext(env, decode->op[0].ptr, res, 2);
972             bit0  = (res & 0x1);
973             bit15 = (res >> 15);
974             /* of = cf ^ result15 */
975             SET_FLAGS_OxxxxC(env, bit0 ^ bit15, bit0);
976         }
977         break;
978     }
979     case 4:
980     {
981         uint32_t bit0, bit31;
982         uint32_t res;
983 
984         count &= 0x1f;
985         if (count) {
986             res = ((uint32_t)decode->op[0].val << count) |
987                    ((uint32_t)decode->op[0].val >> (32 - count));
988 
989             write_val_ext(env, decode->op[0].ptr, res, 4);
990             bit0  = (res & 0x1);
991             bit31 = (res >> 31);
992             /* of = cf ^ result31 */
993             SET_FLAGS_OxxxxC(env, bit0 ^ bit31, bit0);
994         }
995         break;
996         }
997     }
998     env->eip += decode->len;
999 }
1000 
1001 
1002 void exec_rcl(CPUX86State *env, struct x86_decode *decode)
1003 {
1004     uint8_t count;
1005     int of = 0, cf = 0;
1006 
1007     fetch_operands(env, decode, 2, true, true, false);
1008     count = decode->op[1].val & 0x1f;
1009 
1010     switch (decode->operand_size) {
1011     case 1:
1012     {
1013         uint8_t op1_8 = decode->op[0].val;
1014         uint8_t res;
1015         count %= 9;
1016         if (!count) {
1017             break;
1018         }
1019 
1020         if (1 == count) {
1021             res = (op1_8 << 1) | get_CF(env);
1022         } else {
1023             res = (op1_8 << count) | (get_CF(env) << (count - 1)) |
1024                    (op1_8 >> (9 - count));
1025         }
1026 
1027         write_val_ext(env, decode->op[0].ptr, res, 1);
1028 
1029         cf = (op1_8 >> (8 - count)) & 0x01;
1030         of = cf ^ (res >> 7); /* of = cf ^ result7 */
1031         SET_FLAGS_OxxxxC(env, of, cf);
1032         break;
1033     }
1034     case 2:
1035     {
1036         uint16_t res;
1037         uint16_t op1_16 = decode->op[0].val;
1038 
1039         count %= 17;
1040         if (!count) {
1041             break;
1042         }
1043 
1044         if (1 == count) {
1045             res = (op1_16 << 1) | get_CF(env);
1046         } else if (count == 16) {
1047             res = (get_CF(env) << 15) | (op1_16 >> 1);
1048         } else { /* 2..15 */
1049             res = (op1_16 << count) | (get_CF(env) << (count - 1)) |
1050                    (op1_16 >> (17 - count));
1051         }
1052 
1053         write_val_ext(env, decode->op[0].ptr, res, 2);
1054 
1055         cf = (op1_16 >> (16 - count)) & 0x1;
1056         of = cf ^ (res >> 15); /* of = cf ^ result15 */
1057         SET_FLAGS_OxxxxC(env, of, cf);
1058         break;
1059     }
1060     case 4:
1061     {
1062         uint32_t res;
1063         uint32_t op1_32 = decode->op[0].val;
1064 
1065         if (!count) {
1066             break;
1067         }
1068 
1069         if (1 == count) {
1070             res = (op1_32 << 1) | get_CF(env);
1071         } else {
1072             res = (op1_32 << count) | (get_CF(env) << (count - 1)) |
1073                    (op1_32 >> (33 - count));
1074         }
1075 
1076         write_val_ext(env, decode->op[0].ptr, res, 4);
1077 
1078         cf = (op1_32 >> (32 - count)) & 0x1;
1079         of = cf ^ (res >> 31); /* of = cf ^ result31 */
1080         SET_FLAGS_OxxxxC(env, of, cf);
1081         break;
1082         }
1083     }
1084     env->eip += decode->len;
1085 }
1086 
1087 void exec_rcr(CPUX86State *env, struct x86_decode *decode)
1088 {
1089     uint8_t count;
1090     int of = 0, cf = 0;
1091 
1092     fetch_operands(env, decode, 2, true, true, false);
1093     count = decode->op[1].val & 0x1f;
1094 
1095     switch (decode->operand_size) {
1096     case 1:
1097     {
1098         uint8_t op1_8 = decode->op[0].val;
1099         uint8_t res;
1100 
1101         count %= 9;
1102         if (!count) {
1103             break;
1104         }
1105         res = (op1_8 >> count) | (get_CF(env) << (8 - count)) |
1106                (op1_8 << (9 - count));
1107 
1108         write_val_ext(env, decode->op[0].ptr, res, 1);
1109 
1110         cf = (op1_8 >> (count - 1)) & 0x1;
1111         of = (((res << 1) ^ res) >> 7) & 0x1; /* of = result6 ^ result7 */
1112         SET_FLAGS_OxxxxC(env, of, cf);
1113         break;
1114     }
1115     case 2:
1116     {
1117         uint16_t op1_16 = decode->op[0].val;
1118         uint16_t res;
1119 
1120         count %= 17;
1121         if (!count) {
1122             break;
1123         }
1124         res = (op1_16 >> count) | (get_CF(env) << (16 - count)) |
1125                (op1_16 << (17 - count));
1126 
1127         write_val_ext(env, decode->op[0].ptr, res, 2);
1128 
1129         cf = (op1_16 >> (count - 1)) & 0x1;
1130         of = ((uint16_t)((res << 1) ^ res) >> 15) & 0x1; /* of = result15 ^
1131                                                             result14 */
1132         SET_FLAGS_OxxxxC(env, of, cf);
1133         break;
1134     }
1135     case 4:
1136     {
1137         uint32_t res;
1138         uint32_t op1_32 = decode->op[0].val;
1139 
1140         if (!count) {
1141             break;
1142         }
1143 
1144         if (1 == count) {
1145             res = (op1_32 >> 1) | (get_CF(env) << 31);
1146         } else {
1147             res = (op1_32 >> count) | (get_CF(env) << (32 - count)) |
1148                    (op1_32 << (33 - count));
1149         }
1150 
1151         write_val_ext(env, decode->op[0].ptr, res, 4);
1152 
1153         cf = (op1_32 >> (count - 1)) & 0x1;
1154         of = ((res << 1) ^ res) >> 31; /* of = result30 ^ result31 */
1155         SET_FLAGS_OxxxxC(env, of, cf);
1156         break;
1157         }
1158     }
1159     env->eip += decode->len;
1160 }
1161 
1162 static void exec_xchg(CPUX86State *env, struct x86_decode *decode)
1163 {
1164     fetch_operands(env, decode, 2, true, true, false);
1165 
1166     write_val_ext(env, decode->op[0].ptr, decode->op[1].val,
1167                   decode->operand_size);
1168     write_val_ext(env, decode->op[1].ptr, decode->op[0].val,
1169                   decode->operand_size);
1170 
1171     env->eip += decode->len;
1172 }
1173 
1174 static void exec_xadd(CPUX86State *env, struct x86_decode *decode)
1175 {
1176     EXEC_2OP_FLAGS_CMD(env, decode, +, SET_FLAGS_OSZAPC_ADD, true);
1177     write_val_ext(env, decode->op[1].ptr, decode->op[0].val,
1178                   decode->operand_size);
1179 
1180     env->eip += decode->len;
1181 }
1182 
1183 static struct cmd_handler {
1184     enum x86_decode_cmd cmd;
1185     void (*handler)(CPUX86State *env, struct x86_decode *ins);
1186 } handlers[] = {
1187     {X86_DECODE_CMD_INVL, NULL,},
1188     {X86_DECODE_CMD_MOV, exec_mov},
1189     {X86_DECODE_CMD_ADD, exec_add},
1190     {X86_DECODE_CMD_OR, exec_or},
1191     {X86_DECODE_CMD_ADC, exec_adc},
1192     {X86_DECODE_CMD_SBB, exec_sbb},
1193     {X86_DECODE_CMD_AND, exec_and},
1194     {X86_DECODE_CMD_SUB, exec_sub},
1195     {X86_DECODE_CMD_NEG, exec_neg},
1196     {X86_DECODE_CMD_XOR, exec_xor},
1197     {X86_DECODE_CMD_CMP, exec_cmp},
1198     {X86_DECODE_CMD_INC, exec_inc},
1199     {X86_DECODE_CMD_DEC, exec_dec},
1200     {X86_DECODE_CMD_TST, exec_tst},
1201     {X86_DECODE_CMD_NOT, exec_not},
1202     {X86_DECODE_CMD_MOVZX, exec_movzx},
1203     {X86_DECODE_CMD_OUT, exec_out},
1204     {X86_DECODE_CMD_IN, exec_in},
1205     {X86_DECODE_CMD_INS, exec_ins},
1206     {X86_DECODE_CMD_OUTS, exec_outs},
1207     {X86_DECODE_CMD_RDMSR, exec_rdmsr},
1208     {X86_DECODE_CMD_WRMSR, exec_wrmsr},
1209     {X86_DECODE_CMD_BT, exec_bt},
1210     {X86_DECODE_CMD_BTR, exec_btr},
1211     {X86_DECODE_CMD_BTC, exec_btc},
1212     {X86_DECODE_CMD_BTS, exec_bts},
1213     {X86_DECODE_CMD_SHL, exec_shl},
1214     {X86_DECODE_CMD_ROL, exec_rol},
1215     {X86_DECODE_CMD_ROR, exec_ror},
1216     {X86_DECODE_CMD_RCR, exec_rcr},
1217     {X86_DECODE_CMD_RCL, exec_rcl},
1218     /*{X86_DECODE_CMD_CPUID, exec_cpuid},*/
1219     {X86_DECODE_CMD_MOVS, exec_movs},
1220     {X86_DECODE_CMD_CMPS, exec_cmps},
1221     {X86_DECODE_CMD_STOS, exec_stos},
1222     {X86_DECODE_CMD_SCAS, exec_scas},
1223     {X86_DECODE_CMD_LODS, exec_lods},
1224     {X86_DECODE_CMD_MOVSX, exec_movsx},
1225     {X86_DECODE_CMD_XCHG, exec_xchg},
1226     {X86_DECODE_CMD_XADD, exec_xadd},
1227 };
1228 
1229 static struct cmd_handler _cmd_handler[X86_DECODE_CMD_LAST];
1230 
1231 const struct x86_emul_ops *emul_ops;
1232 
1233 static void init_cmd_handler(void)
1234 {
1235     int i;
1236     for (i = 0; i < ARRAY_SIZE(handlers); i++) {
1237         _cmd_handler[handlers[i].cmd] = handlers[i];
1238     }
1239 }
1240 
1241 bool exec_instruction(CPUX86State *env, struct x86_decode *ins)
1242 {
1243     if (!_cmd_handler[ins->cmd].handler) {
1244         printf("Unimplemented handler (" TARGET_FMT_lx ") for %d (%x %x) \n", env->eip,
1245                 ins->cmd, ins->opcode[0],
1246                 ins->opcode_len > 1 ? ins->opcode[1] : 0);
1247         env->eip += ins->len;
1248         return true;
1249     }
1250 
1251     _cmd_handler[ins->cmd].handler(env, ins);
1252     return true;
1253 }
1254 
1255 void init_emu(const struct x86_emul_ops *o)
1256 {
1257     emul_ops = o;
1258     init_cmd_handler();
1259 }
1260