xref: /qemu/target/i386/emulate/x86_emu.c (revision d521fdc73f6ec09fd3f7a37913a6344c86b6c32c)
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], 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], 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], 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 
read_reg(CPUX86State * env,int reg,int size)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 
write_reg(CPUX86State * env,int reg,target_ulong val,int size)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 
read_val_from_reg(void * reg_ptr,int size)124 target_ulong read_val_from_reg(void *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 
write_val_to_reg(void * reg_ptr,target_ulong val,int size)147 void write_val_to_reg(void *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 
write_val_to_mem(CPUX86State * env,target_ulong ptr,target_ulong val,int size)167 static void write_val_to_mem(CPUX86State *env, target_ulong ptr, target_ulong val, int size)
168 {
169     emul_ops->write_mem(env_cpu(env), &val, ptr, size);
170 }
171 
write_val_ext(CPUX86State * env,struct x86_decode_op * decode,target_ulong val,int size)172 void write_val_ext(CPUX86State *env, struct x86_decode_op *decode, target_ulong val, int size)
173 {
174     if (decode->type == X86_VAR_REG) {
175         write_val_to_reg(decode->regptr, val, size);
176     } else {
177         write_val_to_mem(env, decode->addr, val, size);
178     }
179 }
180 
read_mmio(CPUX86State * env,target_ulong ptr,int bytes)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 
read_val_from_mem(CPUX86State * env,target_long ptr,int size)188 static target_ulong read_val_from_mem(CPUX86State *env, target_long ptr, int size)
189 {
190     target_ulong val;
191     uint8_t *mmio_ptr;
192 
193     mmio_ptr = read_mmio(env, ptr, size);
194     switch (size) {
195     case 1:
196         val = *(uint8_t *)mmio_ptr;
197         break;
198     case 2:
199         val = *(uint16_t *)mmio_ptr;
200         break;
201     case 4:
202         val = *(uint32_t *)mmio_ptr;
203         break;
204     case 8:
205         val = *(uint64_t *)mmio_ptr;
206         break;
207     default:
208         VM_PANIC("bad size\n");
209         break;
210     }
211     return val;
212 }
213 
read_val_ext(CPUX86State * env,struct x86_decode_op * decode,int size)214 target_ulong read_val_ext(CPUX86State *env, struct x86_decode_op *decode, int size)
215 {
216     if (decode->type == X86_VAR_REG) {
217         return read_val_from_reg(decode->regptr, size);
218     } else {
219         return read_val_from_mem(env, decode->addr, size);
220     }
221 }
222 
fetch_operands(CPUX86State * env,struct x86_decode * decode,int n,bool val_op0,bool val_op1,bool val_op2)223 static void fetch_operands(CPUX86State *env, struct x86_decode *decode,
224                            int n, bool val_op0, bool val_op1, bool val_op2)
225 {
226     int i;
227     bool calc_val[3] = {val_op0, val_op1, val_op2};
228 
229     for (i = 0; i < n; i++) {
230         switch (decode->op[i].type) {
231         case X86_VAR_IMMEDIATE:
232             break;
233         case X86_VAR_REG:
234             VM_PANIC_ON(!decode->op[i].regptr);
235             if (calc_val[i]) {
236                 decode->op[i].val = read_val_from_reg(decode->op[i].regptr,
237                                                       decode->operand_size);
238             }
239             break;
240         case X86_VAR_RM:
241             calc_modrm_operand(env, decode, &decode->op[i]);
242             if (calc_val[i]) {
243                 decode->op[i].val = read_val_ext(env, &decode->op[i],
244                                                  decode->operand_size);
245             }
246             break;
247         case X86_VAR_OFFSET:
248             decode->op[i].addr = decode_linear_addr(env, decode,
249                                                     decode->op[i].addr,
250                                                     R_DS);
251             if (calc_val[i]) {
252                 decode->op[i].val = read_val_ext(env, &decode->op[i],
253                                                  decode->operand_size);
254             }
255             break;
256         default:
257             break;
258         }
259     }
260 }
261 
exec_mov(CPUX86State * env,struct x86_decode * decode)262 static void exec_mov(CPUX86State *env, struct x86_decode *decode)
263 {
264     fetch_operands(env, decode, 2, false, true, false);
265     write_val_ext(env, &decode->op[0], decode->op[1].val,
266                   decode->operand_size);
267 
268     env->eip += decode->len;
269 }
270 
exec_add(CPUX86State * env,struct x86_decode * decode)271 static void exec_add(CPUX86State *env, struct x86_decode *decode)
272 {
273     EXEC_2OP_FLAGS_CMD(env, decode, +, SET_FLAGS_OSZAPC_ADD, true);
274     env->eip += decode->len;
275 }
276 
exec_or(CPUX86State * env,struct x86_decode * decode)277 static void exec_or(CPUX86State *env, struct x86_decode *decode)
278 {
279     EXEC_2OP_FLAGS_CMD(env, decode, |, SET_FLAGS_OSZAPC_LOGIC, true);
280     env->eip += decode->len;
281 }
282 
exec_adc(CPUX86State * env,struct x86_decode * decode)283 static void exec_adc(CPUX86State *env, struct x86_decode *decode)
284 {
285     EXEC_2OP_FLAGS_CMD(env, decode, +get_CF(env)+, SET_FLAGS_OSZAPC_ADD, true);
286     env->eip += decode->len;
287 }
288 
exec_sbb(CPUX86State * env,struct x86_decode * decode)289 static void exec_sbb(CPUX86State *env, struct x86_decode *decode)
290 {
291     EXEC_2OP_FLAGS_CMD(env, decode, -get_CF(env)-, SET_FLAGS_OSZAPC_SUB, true);
292     env->eip += decode->len;
293 }
294 
exec_and(CPUX86State * env,struct x86_decode * decode)295 static void exec_and(CPUX86State *env, struct x86_decode *decode)
296 {
297     EXEC_2OP_FLAGS_CMD(env, decode, &, SET_FLAGS_OSZAPC_LOGIC, true);
298     env->eip += decode->len;
299 }
300 
exec_sub(CPUX86State * env,struct x86_decode * decode)301 static void exec_sub(CPUX86State *env, struct x86_decode *decode)
302 {
303     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, true);
304     env->eip += decode->len;
305 }
306 
exec_xor(CPUX86State * env,struct x86_decode * decode)307 static void exec_xor(CPUX86State *env, struct x86_decode *decode)
308 {
309     EXEC_2OP_FLAGS_CMD(env, decode, ^, SET_FLAGS_OSZAPC_LOGIC, true);
310     env->eip += decode->len;
311 }
312 
exec_neg(CPUX86State * env,struct x86_decode * decode)313 static void exec_neg(CPUX86State *env, struct x86_decode *decode)
314 {
315     /*EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);*/
316     int32_t val;
317     fetch_operands(env, decode, 2, true, true, false);
318 
319     val = 0 - sign(decode->op[1].val, decode->operand_size);
320     write_val_ext(env, &decode->op[1], val, decode->operand_size);
321 
322     if (4 == decode->operand_size) {
323         SET_FLAGS_OSZAPC_SUB32(env, 0, 0 - val, val);
324     } else if (2 == decode->operand_size) {
325         SET_FLAGS_OSZAPC_SUB16(env, 0, 0 - val, val);
326     } else if (1 == decode->operand_size) {
327         SET_FLAGS_OSZAPC_SUB8(env, 0, 0 - val, val);
328     } else {
329         VM_PANIC("bad op size\n");
330     }
331 
332     /*lflags_to_rflags(env);*/
333     env->eip += decode->len;
334 }
335 
exec_cmp(CPUX86State * env,struct x86_decode * decode)336 static void exec_cmp(CPUX86State *env, struct x86_decode *decode)
337 {
338     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);
339     env->eip += decode->len;
340 }
341 
exec_inc(CPUX86State * env,struct x86_decode * decode)342 static void exec_inc(CPUX86State *env, struct x86_decode *decode)
343 {
344     decode->op[1].type = X86_VAR_IMMEDIATE;
345     decode->op[1].val = 0;
346 
347     EXEC_2OP_FLAGS_CMD(env, decode, +1+, SET_FLAGS_OSZAP_ADD, true);
348 
349     env->eip += decode->len;
350 }
351 
exec_dec(CPUX86State * env,struct x86_decode * decode)352 static void exec_dec(CPUX86State *env, struct x86_decode *decode)
353 {
354     decode->op[1].type = X86_VAR_IMMEDIATE;
355     decode->op[1].val = 0;
356 
357     EXEC_2OP_FLAGS_CMD(env, decode, -1-, SET_FLAGS_OSZAP_SUB, true);
358     env->eip += decode->len;
359 }
360 
exec_tst(CPUX86State * env,struct x86_decode * decode)361 static void exec_tst(CPUX86State *env, struct x86_decode *decode)
362 {
363     EXEC_2OP_FLAGS_CMD(env, decode, &, SET_FLAGS_OSZAPC_LOGIC, false);
364     env->eip += decode->len;
365 }
366 
exec_not(CPUX86State * env,struct x86_decode * decode)367 static void exec_not(CPUX86State *env, struct x86_decode *decode)
368 {
369     fetch_operands(env, decode, 1, true, false, false);
370 
371     write_val_ext(env, &decode->op[0], ~decode->op[0].val,
372                   decode->operand_size);
373     env->eip += decode->len;
374 }
375 
exec_movzx(CPUX86State * env,struct x86_decode * decode)376 void exec_movzx(CPUX86State *env, struct x86_decode *decode)
377 {
378     int src_op_size;
379     int op_size = decode->operand_size;
380 
381     fetch_operands(env, decode, 1, false, false, false);
382 
383     if (0xb6 == decode->opcode[1]) {
384         src_op_size = 1;
385     } else {
386         src_op_size = 2;
387     }
388     decode->operand_size = src_op_size;
389     calc_modrm_operand(env, decode, &decode->op[1]);
390     decode->op[1].val = read_val_ext(env, &decode->op[1], src_op_size);
391     write_val_ext(env, &decode->op[0], decode->op[1].val, op_size);
392 
393     env->eip += decode->len;
394 }
395 
exec_out(CPUX86State * env,struct x86_decode * decode)396 static void exec_out(CPUX86State *env, struct x86_decode *decode)
397 {
398     switch (decode->opcode[0]) {
399     case 0xe6:
400         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &AL(env), 1, 1, 1);
401         break;
402     case 0xe7:
403         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &RAX(env), 1,
404                             decode->operand_size, 1);
405         break;
406     case 0xee:
407         emul_ops->handle_io(env_cpu(env), DX(env), &AL(env), 1, 1, 1);
408         break;
409     case 0xef:
410         emul_ops->handle_io(env_cpu(env), DX(env), &RAX(env), 1,
411                             decode->operand_size, 1);
412         break;
413     default:
414         VM_PANIC("Bad out opcode\n");
415         break;
416     }
417     env->eip += decode->len;
418 }
419 
exec_in(CPUX86State * env,struct x86_decode * decode)420 static void exec_in(CPUX86State *env, struct x86_decode *decode)
421 {
422     target_ulong val = 0;
423     switch (decode->opcode[0]) {
424     case 0xe4:
425         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &AL(env), 0, 1, 1);
426         break;
427     case 0xe5:
428         emul_ops->handle_io(env_cpu(env), decode->op[0].val, &val, 0,
429                       decode->operand_size, 1);
430         if (decode->operand_size == 2) {
431             AX(env) = val;
432         } else {
433             RAX(env) = (uint32_t)val;
434         }
435         break;
436     case 0xec:
437         emul_ops->handle_io(env_cpu(env), DX(env), &AL(env), 0, 1, 1);
438         break;
439     case 0xed:
440         emul_ops->handle_io(env_cpu(env), DX(env), &val, 0,
441                             decode->operand_size, 1);
442         if (decode->operand_size == 2) {
443             AX(env) = val;
444         } else {
445             RAX(env) = (uint32_t)val;
446         }
447 
448         break;
449     default:
450         VM_PANIC("Bad in opcode\n");
451         break;
452     }
453 
454     env->eip += decode->len;
455 }
456 
string_increment_reg(CPUX86State * env,int reg,struct x86_decode * decode)457 static inline void string_increment_reg(CPUX86State *env, int reg,
458                                         struct x86_decode *decode)
459 {
460     target_ulong val = read_reg(env, reg, decode->addressing_size);
461     if (env->eflags & DF_MASK) {
462         val -= decode->operand_size;
463     } else {
464         val += decode->operand_size;
465     }
466     write_reg(env, reg, val, decode->addressing_size);
467 }
468 
string_rep(CPUX86State * env,struct x86_decode * decode,void (* func)(CPUX86State * env,struct x86_decode * ins),int rep)469 static inline void string_rep(CPUX86State *env, struct x86_decode *decode,
470                               void (*func)(CPUX86State *env,
471                                            struct x86_decode *ins), int rep)
472 {
473     target_ulong rcx = read_reg(env, R_ECX, decode->addressing_size);
474     while (rcx--) {
475         func(env, decode);
476         write_reg(env, R_ECX, rcx, decode->addressing_size);
477         if ((PREFIX_REP == rep) && !env->cc_dst) {
478             break;
479         }
480         if ((PREFIX_REPN == rep) && env->cc_dst) {
481             break;
482         }
483     }
484 }
485 
exec_ins_single(CPUX86State * env,struct x86_decode * decode)486 static void exec_ins_single(CPUX86State *env, struct x86_decode *decode)
487 {
488     target_ulong addr = linear_addr_size(env_cpu(env), RDI(env),
489                                          decode->addressing_size, R_ES);
490 
491     emul_ops->handle_io(env_cpu(env), DX(env), env->emu_mmio_buf, 0,
492                         decode->operand_size, 1);
493     emul_ops->write_mem(env_cpu(env), env->emu_mmio_buf, addr,
494                         decode->operand_size);
495 
496     string_increment_reg(env, R_EDI, decode);
497 }
498 
exec_ins(CPUX86State * env,struct x86_decode * decode)499 static void exec_ins(CPUX86State *env, struct x86_decode *decode)
500 {
501     if (decode->rep) {
502         string_rep(env, decode, exec_ins_single, 0);
503     } else {
504         exec_ins_single(env, decode);
505     }
506 
507     env->eip += decode->len;
508 }
509 
exec_outs_single(CPUX86State * env,struct x86_decode * decode)510 static void exec_outs_single(CPUX86State *env, struct x86_decode *decode)
511 {
512     target_ulong addr = decode_linear_addr(env, decode, RSI(env), R_DS);
513 
514     emul_ops->read_mem(env_cpu(env), env->emu_mmio_buf, addr,
515                        decode->operand_size);
516     emul_ops->handle_io(env_cpu(env), DX(env), env->emu_mmio_buf, 1,
517                         decode->operand_size, 1);
518 
519     string_increment_reg(env, R_ESI, decode);
520 }
521 
exec_outs(CPUX86State * env,struct x86_decode * decode)522 static void exec_outs(CPUX86State *env, struct x86_decode *decode)
523 {
524     if (decode->rep) {
525         string_rep(env, decode, exec_outs_single, 0);
526     } else {
527         exec_outs_single(env, decode);
528     }
529 
530     env->eip += decode->len;
531 }
532 
exec_movs_single(CPUX86State * env,struct x86_decode * decode)533 static void exec_movs_single(CPUX86State *env, struct x86_decode *decode)
534 {
535     target_ulong src_addr;
536     target_ulong dst_addr;
537     target_ulong val;
538 
539     src_addr = decode_linear_addr(env, decode, RSI(env), R_DS);
540     dst_addr = linear_addr_size(env_cpu(env), RDI(env),
541                                 decode->addressing_size, R_ES);
542 
543     val = read_val_from_mem(env, src_addr, decode->operand_size);
544     write_val_to_mem(env, dst_addr, val, decode->operand_size);
545 
546     string_increment_reg(env, R_ESI, decode);
547     string_increment_reg(env, R_EDI, decode);
548 }
549 
exec_movs(CPUX86State * env,struct x86_decode * decode)550 static void exec_movs(CPUX86State *env, struct x86_decode *decode)
551 {
552     if (decode->rep) {
553         string_rep(env, decode, exec_movs_single, 0);
554     } else {
555         exec_movs_single(env, decode);
556     }
557 
558     env->eip += decode->len;
559 }
560 
exec_cmps_single(CPUX86State * env,struct x86_decode * decode)561 static void exec_cmps_single(CPUX86State *env, struct x86_decode *decode)
562 {
563     target_ulong src_addr;
564     target_ulong dst_addr;
565 
566     src_addr = decode_linear_addr(env, decode, RSI(env), R_DS);
567     dst_addr = linear_addr_size(env_cpu(env), RDI(env),
568                                 decode->addressing_size, R_ES);
569 
570     decode->op[0].type = X86_VAR_IMMEDIATE;
571     decode->op[0].val = read_val_from_mem(env, src_addr, decode->operand_size);
572     decode->op[1].type = X86_VAR_IMMEDIATE;
573     decode->op[1].val = read_val_from_mem(env, dst_addr, decode->operand_size);
574 
575     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);
576 
577     string_increment_reg(env, R_ESI, decode);
578     string_increment_reg(env, R_EDI, decode);
579 }
580 
exec_cmps(CPUX86State * env,struct x86_decode * decode)581 static void exec_cmps(CPUX86State *env, struct x86_decode *decode)
582 {
583     if (decode->rep) {
584         string_rep(env, decode, exec_cmps_single, decode->rep);
585     } else {
586         exec_cmps_single(env, decode);
587     }
588     env->eip += decode->len;
589 }
590 
591 
exec_stos_single(CPUX86State * env,struct x86_decode * decode)592 static void exec_stos_single(CPUX86State *env, struct x86_decode *decode)
593 {
594     target_ulong addr;
595     target_ulong val;
596 
597     addr = linear_addr_size(env_cpu(env), RDI(env),
598                             decode->addressing_size, R_ES);
599     val = read_reg(env, R_EAX, decode->operand_size);
600     emul_ops->write_mem(env_cpu(env), &val, addr, decode->operand_size);
601 
602     string_increment_reg(env, R_EDI, decode);
603 }
604 
605 
exec_stos(CPUX86State * env,struct x86_decode * decode)606 static void exec_stos(CPUX86State *env, struct x86_decode *decode)
607 {
608     if (decode->rep) {
609         string_rep(env, decode, exec_stos_single, 0);
610     } else {
611         exec_stos_single(env, decode);
612     }
613 
614     env->eip += decode->len;
615 }
616 
exec_scas_single(CPUX86State * env,struct x86_decode * decode)617 static void exec_scas_single(CPUX86State *env, struct x86_decode *decode)
618 {
619     target_ulong addr;
620 
621     addr = linear_addr_size(env_cpu(env), RDI(env),
622                             decode->addressing_size, R_ES);
623     decode->op[1].type = X86_VAR_IMMEDIATE;
624     emul_ops->read_mem(env_cpu(env), &decode->op[1].val, addr, decode->operand_size);
625 
626     EXEC_2OP_FLAGS_CMD(env, decode, -, SET_FLAGS_OSZAPC_SUB, false);
627     string_increment_reg(env, R_EDI, decode);
628 }
629 
exec_scas(CPUX86State * env,struct x86_decode * decode)630 static void exec_scas(CPUX86State *env, struct x86_decode *decode)
631 {
632     decode->op[0].type = X86_VAR_REG;
633     decode->op[0].reg = R_EAX;
634     if (decode->rep) {
635         string_rep(env, decode, exec_scas_single, decode->rep);
636     } else {
637         exec_scas_single(env, decode);
638     }
639 
640     env->eip += decode->len;
641 }
642 
exec_lods_single(CPUX86State * env,struct x86_decode * decode)643 static void exec_lods_single(CPUX86State *env, struct x86_decode *decode)
644 {
645     target_ulong addr;
646     target_ulong val = 0;
647 
648     addr = decode_linear_addr(env, decode, RSI(env), R_DS);
649     emul_ops->read_mem(env_cpu(env), &val, addr,  decode->operand_size);
650     write_reg(env, R_EAX, val, decode->operand_size);
651 
652     string_increment_reg(env, R_ESI, decode);
653 }
654 
exec_lods(CPUX86State * env,struct x86_decode * decode)655 static void exec_lods(CPUX86State *env, struct x86_decode *decode)
656 {
657     if (decode->rep) {
658         string_rep(env, decode, exec_lods_single, 0);
659     } else {
660         exec_lods_single(env, decode);
661     }
662 
663     env->eip += decode->len;
664 }
665 
x86_emul_raise_exception(CPUX86State * env,int exception_index,int error_code)666 void x86_emul_raise_exception(CPUX86State *env, int exception_index, int error_code)
667 {
668     env->exception_nr = exception_index;
669     env->error_code = error_code;
670     env->has_error_code = true;
671     env->exception_injected = 1;
672 }
673 
exec_rdmsr(CPUX86State * env,struct x86_decode * decode)674 static void exec_rdmsr(CPUX86State *env, struct x86_decode *decode)
675 {
676     emul_ops->simulate_rdmsr(env_cpu(env));
677     env->eip += decode->len;
678 }
679 
exec_wrmsr(CPUX86State * env,struct x86_decode * decode)680 static void exec_wrmsr(CPUX86State *env, struct x86_decode *decode)
681 {
682     emul_ops->simulate_wrmsr(env_cpu(env));
683     env->eip += decode->len;
684 }
685 
686 /*
687  * flag:
688  * 0 - bt, 1 - btc, 2 - bts, 3 - btr
689  */
do_bt(CPUX86State * env,struct x86_decode * decode,int flag)690 static void do_bt(CPUX86State *env, struct x86_decode *decode, int flag)
691 {
692     int32_t displacement;
693     uint8_t index;
694     bool cf;
695     int mask = (4 == decode->operand_size) ? 0x1f : 0xf;
696 
697     VM_PANIC_ON(decode->rex.rex);
698 
699     fetch_operands(env, decode, 2, false, true, false);
700     index = decode->op[1].val & mask;
701 
702     if (decode->op[0].type != X86_VAR_REG) {
703         if (4 == decode->operand_size) {
704             displacement = ((int32_t) (decode->op[1].val & 0xffffffe0)) / 32;
705             decode->op[0].addr += 4 * displacement;
706         } else if (2 == decode->operand_size) {
707             displacement = ((int16_t) (decode->op[1].val & 0xfff0)) / 16;
708             decode->op[0].addr += 2 * displacement;
709         } else {
710             VM_PANIC("bt 64bit\n");
711         }
712     }
713     decode->op[0].val = read_val_ext(env, &decode->op[0],
714                                      decode->operand_size);
715     cf = (decode->op[0].val >> index) & 0x01;
716 
717     switch (flag) {
718     case 0:
719         set_CF(env, cf);
720         return;
721     case 1:
722         decode->op[0].val ^= (1u << index);
723         break;
724     case 2:
725         decode->op[0].val |= (1u << index);
726         break;
727     case 3:
728         decode->op[0].val &= ~(1u << index);
729         break;
730     }
731     write_val_ext(env, &decode->op[0], decode->op[0].val,
732                   decode->operand_size);
733     set_CF(env, cf);
734 }
735 
exec_bt(CPUX86State * env,struct x86_decode * decode)736 static void exec_bt(CPUX86State *env, struct x86_decode *decode)
737 {
738     do_bt(env, decode, 0);
739     env->eip += decode->len;
740 }
741 
exec_btc(CPUX86State * env,struct x86_decode * decode)742 static void exec_btc(CPUX86State *env, struct x86_decode *decode)
743 {
744     do_bt(env, decode, 1);
745     env->eip += decode->len;
746 }
747 
exec_btr(CPUX86State * env,struct x86_decode * decode)748 static void exec_btr(CPUX86State *env, struct x86_decode *decode)
749 {
750     do_bt(env, decode, 3);
751     env->eip += decode->len;
752 }
753 
exec_bts(CPUX86State * env,struct x86_decode * decode)754 static void exec_bts(CPUX86State *env, struct x86_decode *decode)
755 {
756     do_bt(env, decode, 2);
757     env->eip += decode->len;
758 }
759 
exec_shl(CPUX86State * env,struct x86_decode * decode)760 void exec_shl(CPUX86State *env, struct x86_decode *decode)
761 {
762     uint8_t count;
763     int of = 0, cf = 0;
764 
765     fetch_operands(env, decode, 2, true, true, false);
766 
767     count = decode->op[1].val;
768     count &= 0x1f;      /* count is masked to 5 bits*/
769     if (!count) {
770         goto exit;
771     }
772 
773     switch (decode->operand_size) {
774     case 1:
775     {
776         uint8_t res = 0;
777         if (count <= 8) {
778             res = (decode->op[0].val << count);
779             cf = (decode->op[0].val >> (8 - count)) & 0x1;
780             of = cf ^ (res >> 7);
781         }
782 
783         write_val_ext(env, &decode->op[0], res, 1);
784         SET_FLAGS_OSZAPC_LOGIC8(env, 0, 0, res);
785         SET_FLAGS_OxxxxC(env, of, cf);
786         break;
787     }
788     case 2:
789     {
790         uint16_t res = 0;
791 
792         /* from bochs */
793         if (count <= 16) {
794             res = (decode->op[0].val << count);
795             cf = (decode->op[0].val >> (16 - count)) & 0x1;
796             of = cf ^ (res >> 15); /* of = cf ^ result15 */
797         }
798 
799         write_val_ext(env, &decode->op[0], res, 2);
800         SET_FLAGS_OSZAPC_LOGIC16(env, 0, 0, res);
801         SET_FLAGS_OxxxxC(env, of, cf);
802         break;
803     }
804     case 4:
805     {
806         uint32_t res = decode->op[0].val << count;
807 
808         write_val_ext(env, &decode->op[0], res, 4);
809         SET_FLAGS_OSZAPC_LOGIC32(env, 0, 0, res);
810         cf = (decode->op[0].val >> (32 - count)) & 0x1;
811         of = cf ^ (res >> 31); /* of = cf ^ result31 */
812         SET_FLAGS_OxxxxC(env, of, cf);
813         break;
814     }
815     default:
816         abort();
817     }
818 
819 exit:
820     /* lflags_to_rflags(env); */
821     env->eip += decode->len;
822 }
823 
exec_movsx(CPUX86State * env,struct x86_decode * decode)824 void exec_movsx(CPUX86State *env, struct x86_decode *decode)
825 {
826     int src_op_size;
827     int op_size = decode->operand_size;
828 
829     fetch_operands(env, decode, 2, false, false, false);
830 
831     if (0xbe == decode->opcode[1]) {
832         src_op_size = 1;
833     } else {
834         src_op_size = 2;
835     }
836 
837     decode->operand_size = src_op_size;
838     calc_modrm_operand(env, decode, &decode->op[1]);
839     decode->op[1].val = sign(read_val_ext(env, &decode->op[1], src_op_size),
840                              src_op_size);
841 
842     write_val_ext(env, &decode->op[0], decode->op[1].val, op_size);
843 
844     env->eip += decode->len;
845 }
846 
exec_ror(CPUX86State * env,struct x86_decode * decode)847 void exec_ror(CPUX86State *env, struct x86_decode *decode)
848 {
849     uint8_t count;
850 
851     fetch_operands(env, decode, 2, true, true, false);
852     count = decode->op[1].val;
853 
854     switch (decode->operand_size) {
855     case 1:
856     {
857         uint32_t bit6, bit7;
858         uint8_t res;
859 
860         if ((count & 0x07) == 0) {
861             if (count & 0x18) {
862                 bit6 = ((uint8_t)decode->op[0].val >> 6) & 1;
863                 bit7 = ((uint8_t)decode->op[0].val >> 7) & 1;
864                 SET_FLAGS_OxxxxC(env, bit6 ^ bit7, bit7);
865              }
866         } else {
867             count &= 0x7; /* use only bottom 3 bits */
868             res = ((uint8_t)decode->op[0].val >> count) |
869                    ((uint8_t)decode->op[0].val << (8 - count));
870             write_val_ext(env, &decode->op[0], res, 1);
871             bit6 = (res >> 6) & 1;
872             bit7 = (res >> 7) & 1;
873             /* set eflags: ROR count affects the following flags: C, O */
874             SET_FLAGS_OxxxxC(env, bit6 ^ bit7, bit7);
875         }
876         break;
877     }
878     case 2:
879     {
880         uint32_t bit14, bit15;
881         uint16_t res;
882 
883         if ((count & 0x0f) == 0) {
884             if (count & 0x10) {
885                 bit14 = ((uint16_t)decode->op[0].val >> 14) & 1;
886                 bit15 = ((uint16_t)decode->op[0].val >> 15) & 1;
887                 /* of = result14 ^ result15 */
888                 SET_FLAGS_OxxxxC(env, bit14 ^ bit15, bit15);
889             }
890         } else {
891             count &= 0x0f;  /* use only 4 LSB's */
892             res = ((uint16_t)decode->op[0].val >> count) |
893                    ((uint16_t)decode->op[0].val << (16 - count));
894             write_val_ext(env, &decode->op[0], res, 2);
895 
896             bit14 = (res >> 14) & 1;
897             bit15 = (res >> 15) & 1;
898             /* of = result14 ^ result15 */
899             SET_FLAGS_OxxxxC(env, bit14 ^ bit15, bit15);
900         }
901         break;
902     }
903     case 4:
904     {
905         uint32_t bit31, bit30;
906         uint32_t res;
907 
908         count &= 0x1f;
909         if (count) {
910             res = ((uint32_t)decode->op[0].val >> count) |
911                    ((uint32_t)decode->op[0].val << (32 - count));
912             write_val_ext(env, &decode->op[0], res, 4);
913 
914             bit31 = (res >> 31) & 1;
915             bit30 = (res >> 30) & 1;
916             /* of = result30 ^ result31 */
917             SET_FLAGS_OxxxxC(env, bit30 ^ bit31, bit31);
918         }
919         break;
920         }
921     }
922     env->eip += decode->len;
923 }
924 
exec_rol(CPUX86State * env,struct x86_decode * decode)925 void exec_rol(CPUX86State *env, struct x86_decode *decode)
926 {
927     uint8_t count;
928 
929     fetch_operands(env, decode, 2, true, true, false);
930     count = decode->op[1].val;
931 
932     switch (decode->operand_size) {
933     case 1:
934     {
935         uint32_t bit0, bit7;
936         uint8_t res;
937 
938         if ((count & 0x07) == 0) {
939             if (count & 0x18) {
940                 bit0 = ((uint8_t)decode->op[0].val & 1);
941                 bit7 = ((uint8_t)decode->op[0].val >> 7);
942                 SET_FLAGS_OxxxxC(env, bit0 ^ bit7, bit0);
943             }
944         }  else {
945             count &= 0x7; /* use only lowest 3 bits */
946             res = ((uint8_t)decode->op[0].val << count) |
947                    ((uint8_t)decode->op[0].val >> (8 - count));
948 
949             write_val_ext(env, &decode->op[0], res, 1);
950             /* set eflags:
951              * ROL count affects the following flags: C, O
952              */
953             bit0 = (res &  1);
954             bit7 = (res >> 7);
955             SET_FLAGS_OxxxxC(env, bit0 ^ bit7, bit0);
956         }
957         break;
958     }
959     case 2:
960     {
961         uint32_t bit0, bit15;
962         uint16_t res;
963 
964         if ((count & 0x0f) == 0) {
965             if (count & 0x10) {
966                 bit0  = ((uint16_t)decode->op[0].val & 0x1);
967                 bit15 = ((uint16_t)decode->op[0].val >> 15);
968                 /* of = cf ^ result15 */
969                 SET_FLAGS_OxxxxC(env, bit0 ^ bit15, bit0);
970             }
971         } else {
972             count &= 0x0f; /* only use bottom 4 bits */
973             res = ((uint16_t)decode->op[0].val << count) |
974                    ((uint16_t)decode->op[0].val >> (16 - count));
975 
976             write_val_ext(env, &decode->op[0], res, 2);
977             bit0  = (res & 0x1);
978             bit15 = (res >> 15);
979             /* of = cf ^ result15 */
980             SET_FLAGS_OxxxxC(env, bit0 ^ bit15, bit0);
981         }
982         break;
983     }
984     case 4:
985     {
986         uint32_t bit0, bit31;
987         uint32_t res;
988 
989         count &= 0x1f;
990         if (count) {
991             res = ((uint32_t)decode->op[0].val << count) |
992                    ((uint32_t)decode->op[0].val >> (32 - count));
993 
994             write_val_ext(env, &decode->op[0], res, 4);
995             bit0  = (res & 0x1);
996             bit31 = (res >> 31);
997             /* of = cf ^ result31 */
998             SET_FLAGS_OxxxxC(env, bit0 ^ bit31, bit0);
999         }
1000         break;
1001         }
1002     }
1003     env->eip += decode->len;
1004 }
1005 
1006 
exec_rcl(CPUX86State * env,struct x86_decode * decode)1007 void exec_rcl(CPUX86State *env, struct x86_decode *decode)
1008 {
1009     uint8_t count;
1010     int of = 0, cf = 0;
1011 
1012     fetch_operands(env, decode, 2, true, true, false);
1013     count = decode->op[1].val & 0x1f;
1014 
1015     switch (decode->operand_size) {
1016     case 1:
1017     {
1018         uint8_t op1_8 = decode->op[0].val;
1019         uint8_t res;
1020         count %= 9;
1021         if (!count) {
1022             break;
1023         }
1024 
1025         if (1 == count) {
1026             res = (op1_8 << 1) | get_CF(env);
1027         } else {
1028             res = (op1_8 << count) | (get_CF(env) << (count - 1)) |
1029                    (op1_8 >> (9 - count));
1030         }
1031 
1032         write_val_ext(env, &decode->op[0], res, 1);
1033 
1034         cf = (op1_8 >> (8 - count)) & 0x01;
1035         of = cf ^ (res >> 7); /* of = cf ^ result7 */
1036         SET_FLAGS_OxxxxC(env, of, cf);
1037         break;
1038     }
1039     case 2:
1040     {
1041         uint16_t res;
1042         uint16_t op1_16 = decode->op[0].val;
1043 
1044         count %= 17;
1045         if (!count) {
1046             break;
1047         }
1048 
1049         if (1 == count) {
1050             res = (op1_16 << 1) | get_CF(env);
1051         } else if (count == 16) {
1052             res = (get_CF(env) << 15) | (op1_16 >> 1);
1053         } else { /* 2..15 */
1054             res = (op1_16 << count) | (get_CF(env) << (count - 1)) |
1055                    (op1_16 >> (17 - count));
1056         }
1057 
1058         write_val_ext(env, &decode->op[0], res, 2);
1059 
1060         cf = (op1_16 >> (16 - count)) & 0x1;
1061         of = cf ^ (res >> 15); /* of = cf ^ result15 */
1062         SET_FLAGS_OxxxxC(env, of, cf);
1063         break;
1064     }
1065     case 4:
1066     {
1067         uint32_t res;
1068         uint32_t op1_32 = decode->op[0].val;
1069 
1070         if (!count) {
1071             break;
1072         }
1073 
1074         if (1 == count) {
1075             res = (op1_32 << 1) | get_CF(env);
1076         } else {
1077             res = (op1_32 << count) | (get_CF(env) << (count - 1)) |
1078                    (op1_32 >> (33 - count));
1079         }
1080 
1081         write_val_ext(env, &decode->op[0], res, 4);
1082 
1083         cf = (op1_32 >> (32 - count)) & 0x1;
1084         of = cf ^ (res >> 31); /* of = cf ^ result31 */
1085         SET_FLAGS_OxxxxC(env, of, cf);
1086         break;
1087         }
1088     }
1089     env->eip += decode->len;
1090 }
1091 
exec_rcr(CPUX86State * env,struct x86_decode * decode)1092 void exec_rcr(CPUX86State *env, struct x86_decode *decode)
1093 {
1094     uint8_t count;
1095     int of = 0, cf = 0;
1096 
1097     fetch_operands(env, decode, 2, true, true, false);
1098     count = decode->op[1].val & 0x1f;
1099 
1100     switch (decode->operand_size) {
1101     case 1:
1102     {
1103         uint8_t op1_8 = decode->op[0].val;
1104         uint8_t res;
1105 
1106         count %= 9;
1107         if (!count) {
1108             break;
1109         }
1110         res = (op1_8 >> count) | (get_CF(env) << (8 - count)) |
1111                (op1_8 << (9 - count));
1112 
1113         write_val_ext(env, &decode->op[0], res, 1);
1114 
1115         cf = (op1_8 >> (count - 1)) & 0x1;
1116         of = (((res << 1) ^ res) >> 7) & 0x1; /* of = result6 ^ result7 */
1117         SET_FLAGS_OxxxxC(env, of, cf);
1118         break;
1119     }
1120     case 2:
1121     {
1122         uint16_t op1_16 = decode->op[0].val;
1123         uint16_t res;
1124 
1125         count %= 17;
1126         if (!count) {
1127             break;
1128         }
1129         res = (op1_16 >> count) | (get_CF(env) << (16 - count)) |
1130                (op1_16 << (17 - count));
1131 
1132         write_val_ext(env, &decode->op[0], res, 2);
1133 
1134         cf = (op1_16 >> (count - 1)) & 0x1;
1135         of = ((uint16_t)((res << 1) ^ res) >> 15) & 0x1; /* of = result15 ^
1136                                                             result14 */
1137         SET_FLAGS_OxxxxC(env, of, cf);
1138         break;
1139     }
1140     case 4:
1141     {
1142         uint32_t res;
1143         uint32_t op1_32 = decode->op[0].val;
1144 
1145         if (!count) {
1146             break;
1147         }
1148 
1149         if (1 == count) {
1150             res = (op1_32 >> 1) | (get_CF(env) << 31);
1151         } else {
1152             res = (op1_32 >> count) | (get_CF(env) << (32 - count)) |
1153                    (op1_32 << (33 - count));
1154         }
1155 
1156         write_val_ext(env, &decode->op[0], res, 4);
1157 
1158         cf = (op1_32 >> (count - 1)) & 0x1;
1159         of = ((res << 1) ^ res) >> 31; /* of = result30 ^ result31 */
1160         SET_FLAGS_OxxxxC(env, of, cf);
1161         break;
1162         }
1163     }
1164     env->eip += decode->len;
1165 }
1166 
exec_xchg(CPUX86State * env,struct x86_decode * decode)1167 static void exec_xchg(CPUX86State *env, struct x86_decode *decode)
1168 {
1169     fetch_operands(env, decode, 2, true, true, false);
1170 
1171     write_val_ext(env, &decode->op[0], decode->op[1].val,
1172                   decode->operand_size);
1173     write_val_ext(env, &decode->op[1], decode->op[0].val,
1174                   decode->operand_size);
1175 
1176     env->eip += decode->len;
1177 }
1178 
exec_xadd(CPUX86State * env,struct x86_decode * decode)1179 static void exec_xadd(CPUX86State *env, struct x86_decode *decode)
1180 {
1181     EXEC_2OP_FLAGS_CMD(env, decode, +, SET_FLAGS_OSZAPC_ADD, true);
1182     write_val_ext(env, &decode->op[1], decode->op[0].val,
1183                   decode->operand_size);
1184 
1185     env->eip += decode->len;
1186 }
1187 
1188 static struct cmd_handler {
1189     enum x86_decode_cmd cmd;
1190     void (*handler)(CPUX86State *env, struct x86_decode *ins);
1191 } handlers[] = {
1192     {X86_DECODE_CMD_INVL, NULL,},
1193     {X86_DECODE_CMD_MOV, exec_mov},
1194     {X86_DECODE_CMD_ADD, exec_add},
1195     {X86_DECODE_CMD_OR, exec_or},
1196     {X86_DECODE_CMD_ADC, exec_adc},
1197     {X86_DECODE_CMD_SBB, exec_sbb},
1198     {X86_DECODE_CMD_AND, exec_and},
1199     {X86_DECODE_CMD_SUB, exec_sub},
1200     {X86_DECODE_CMD_NEG, exec_neg},
1201     {X86_DECODE_CMD_XOR, exec_xor},
1202     {X86_DECODE_CMD_CMP, exec_cmp},
1203     {X86_DECODE_CMD_INC, exec_inc},
1204     {X86_DECODE_CMD_DEC, exec_dec},
1205     {X86_DECODE_CMD_TST, exec_tst},
1206     {X86_DECODE_CMD_NOT, exec_not},
1207     {X86_DECODE_CMD_MOVZX, exec_movzx},
1208     {X86_DECODE_CMD_OUT, exec_out},
1209     {X86_DECODE_CMD_IN, exec_in},
1210     {X86_DECODE_CMD_INS, exec_ins},
1211     {X86_DECODE_CMD_OUTS, exec_outs},
1212     {X86_DECODE_CMD_RDMSR, exec_rdmsr},
1213     {X86_DECODE_CMD_WRMSR, exec_wrmsr},
1214     {X86_DECODE_CMD_BT, exec_bt},
1215     {X86_DECODE_CMD_BTR, exec_btr},
1216     {X86_DECODE_CMD_BTC, exec_btc},
1217     {X86_DECODE_CMD_BTS, exec_bts},
1218     {X86_DECODE_CMD_SHL, exec_shl},
1219     {X86_DECODE_CMD_ROL, exec_rol},
1220     {X86_DECODE_CMD_ROR, exec_ror},
1221     {X86_DECODE_CMD_RCR, exec_rcr},
1222     {X86_DECODE_CMD_RCL, exec_rcl},
1223     /*{X86_DECODE_CMD_CPUID, exec_cpuid},*/
1224     {X86_DECODE_CMD_MOVS, exec_movs},
1225     {X86_DECODE_CMD_CMPS, exec_cmps},
1226     {X86_DECODE_CMD_STOS, exec_stos},
1227     {X86_DECODE_CMD_SCAS, exec_scas},
1228     {X86_DECODE_CMD_LODS, exec_lods},
1229     {X86_DECODE_CMD_MOVSX, exec_movsx},
1230     {X86_DECODE_CMD_XCHG, exec_xchg},
1231     {X86_DECODE_CMD_XADD, exec_xadd},
1232 };
1233 
1234 static struct cmd_handler _cmd_handler[X86_DECODE_CMD_LAST];
1235 
1236 const struct x86_emul_ops *emul_ops;
1237 
init_cmd_handler(void)1238 static void init_cmd_handler(void)
1239 {
1240     int i;
1241     for (i = 0; i < ARRAY_SIZE(handlers); i++) {
1242         _cmd_handler[handlers[i].cmd] = handlers[i];
1243     }
1244 }
1245 
exec_instruction(CPUX86State * env,struct x86_decode * ins)1246 bool exec_instruction(CPUX86State *env, struct x86_decode *ins)
1247 {
1248     if (!_cmd_handler[ins->cmd].handler) {
1249         printf("Unimplemented handler (" TARGET_FMT_lx ") for %d (%x %x) \n", env->eip,
1250                 ins->cmd, ins->opcode[0],
1251                 ins->opcode_len > 1 ? ins->opcode[1] : 0);
1252         env->eip += ins->len;
1253         return true;
1254     }
1255 
1256     _cmd_handler[ins->cmd].handler(env, ins);
1257     return true;
1258 }
1259 
init_emu(const struct x86_emul_ops * o)1260 void init_emu(const struct x86_emul_ops *o)
1261 {
1262     emul_ops = o;
1263     init_cmd_handler();
1264 }
1265