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Change -drive parsing so that paths don't have to be double-escaped (Laurent Vivier...
[qemu/qemu_0_9_1_stable.git] / linux-user / vm86.c
blobd87174b560d0c0a8bfb6dd0fd57539289ebff78b
1 /*
2 * vm86 linux syscall support
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20 #include <stdlib.h>
21 #include <stdio.h>
22 #include <stdarg.h>
23 #include <string.h>
24 #include <errno.h>
25 #include <unistd.h>
26
27 #include "qemu.h"
28
29 //#define DEBUG_VM86
30
31 #define set_flags(X,new,mask) \
32 ((X) = ((X) & ~(mask)) | ((new) & (mask)))
33
34 #define SAFE_MASK (0xDD5)
35 #define RETURN_MASK (0xDFF)
36
37 static inline int is_revectored(int nr, struct target_revectored_struct *bitmap)
38 {
39 return (((uint8_t *)bitmap)[nr >> 3] >> (nr & 7)) & 1;
40 }
41
42 static inline void vm_putw(uint32_t segptr, unsigned int reg16, unsigned int val)
43 {
44 stw(segptr + (reg16 & 0xffff), val);
45 }
46
47 static inline void vm_putl(uint32_t segptr, unsigned int reg16, unsigned int val)
48 {
49 stl(segptr + (reg16 & 0xffff), val);
50 }
51
52 static inline unsigned int vm_getb(uint32_t segptr, unsigned int reg16)
53 {
54 return ldub(segptr + (reg16 & 0xffff));
55 }
56
57 static inline unsigned int vm_getw(uint32_t segptr, unsigned int reg16)
58 {
59 return lduw(segptr + (reg16 & 0xffff));
60 }
61
62 static inline unsigned int vm_getl(uint32_t segptr, unsigned int reg16)
63 {
64 return ldl(segptr + (reg16 & 0xffff));
65 }
66
67 void save_v86_state(CPUX86State *env)
68 {
69 TaskState *ts = env->opaque;
70 struct target_vm86plus_struct * target_v86;
71
72 if (!lock_user_struct(VERIFY_WRITE, target_v86, ts->target_v86, 0))
73 /* FIXME - should return an error */
74 return;
75 /* put the VM86 registers in the userspace register structure */
76 target_v86->regs.eax = tswap32(env->regs[R_EAX]);
77 target_v86->regs.ebx = tswap32(env->regs[R_EBX]);
78 target_v86->regs.ecx = tswap32(env->regs[R_ECX]);
79 target_v86->regs.edx = tswap32(env->regs[R_EDX]);
80 target_v86->regs.esi = tswap32(env->regs[R_ESI]);
81 target_v86->regs.edi = tswap32(env->regs[R_EDI]);
82 target_v86->regs.ebp = tswap32(env->regs[R_EBP]);
83 target_v86->regs.esp = tswap32(env->regs[R_ESP]);
84 target_v86->regs.eip = tswap32(env->eip);
85 target_v86->regs.cs = tswap16(env->segs[R_CS].selector);
86 target_v86->regs.ss = tswap16(env->segs[R_SS].selector);
87 target_v86->regs.ds = tswap16(env->segs[R_DS].selector);
88 target_v86->regs.es = tswap16(env->segs[R_ES].selector);
89 target_v86->regs.fs = tswap16(env->segs[R_FS].selector);
90 target_v86->regs.gs = tswap16(env->segs[R_GS].selector);
91 set_flags(env->eflags, ts->v86flags, VIF_MASK | ts->v86mask);
92 target_v86->regs.eflags = tswap32(env->eflags);
93 unlock_user_struct(target_v86, ts->target_v86, 1);
94 #ifdef DEBUG_VM86
95 fprintf(logfile, "save_v86_state: eflags=%08x cs:ip=%04x:%04x\n",
96 env->eflags, env->segs[R_CS].selector, env->eip);
97 #endif
98
99 /* restore 32 bit registers */
100 env->regs[R_EAX] = ts->vm86_saved_regs.eax;
101 env->regs[R_EBX] = ts->vm86_saved_regs.ebx;
102 env->regs[R_ECX] = ts->vm86_saved_regs.ecx;
103 env->regs[R_EDX] = ts->vm86_saved_regs.edx;
104 env->regs[R_ESI] = ts->vm86_saved_regs.esi;
105 env->regs[R_EDI] = ts->vm86_saved_regs.edi;
106 env->regs[R_EBP] = ts->vm86_saved_regs.ebp;
107 env->regs[R_ESP] = ts->vm86_saved_regs.esp;
108 env->eflags = ts->vm86_saved_regs.eflags;
109 env->eip = ts->vm86_saved_regs.eip;
110
111 cpu_x86_load_seg(env, R_CS, ts->vm86_saved_regs.cs);
112 cpu_x86_load_seg(env, R_SS, ts->vm86_saved_regs.ss);
113 cpu_x86_load_seg(env, R_DS, ts->vm86_saved_regs.ds);
114 cpu_x86_load_seg(env, R_ES, ts->vm86_saved_regs.es);
115 cpu_x86_load_seg(env, R_FS, ts->vm86_saved_regs.fs);
116 cpu_x86_load_seg(env, R_GS, ts->vm86_saved_regs.gs);
117 }
118
119 /* return from vm86 mode to 32 bit. The vm86() syscall will return
120 'retval' */
121 static inline void return_to_32bit(CPUX86State *env, int retval)
122 {
123 #ifdef DEBUG_VM86
124 fprintf(logfile, "return_to_32bit: ret=0x%x\n", retval);
125 #endif
126 save_v86_state(env);
127 env->regs[R_EAX] = retval;
128 }
129
130 static inline int set_IF(CPUX86State *env)
131 {
132 TaskState *ts = env->opaque;
133
134 ts->v86flags |= VIF_MASK;
135 if (ts->v86flags & VIP_MASK) {
136 return_to_32bit(env, TARGET_VM86_STI);
137 return 1;
138 }
139 return 0;
140 }
141
142 static inline void clear_IF(CPUX86State *env)
143 {
144 TaskState *ts = env->opaque;
145
146 ts->v86flags &= ~VIF_MASK;
147 }
148
149 static inline void clear_TF(CPUX86State *env)
150 {
151 env->eflags &= ~TF_MASK;
152 }
153
154 static inline void clear_AC(CPUX86State *env)
155 {
156 env->eflags &= ~AC_MASK;
157 }
158
159 static inline int set_vflags_long(unsigned long eflags, CPUX86State *env)
160 {
161 TaskState *ts = env->opaque;
162
163 set_flags(ts->v86flags, eflags, ts->v86mask);
164 set_flags(env->eflags, eflags, SAFE_MASK);
165 if (eflags & IF_MASK)
166 return set_IF(env);
167 else
168 clear_IF(env);
169 return 0;
170 }
171
172 static inline int set_vflags_short(unsigned short flags, CPUX86State *env)
173 {
174 TaskState *ts = env->opaque;
175
176 set_flags(ts->v86flags, flags, ts->v86mask & 0xffff);
177 set_flags(env->eflags, flags, SAFE_MASK);
178 if (flags & IF_MASK)
179 return set_IF(env);
180 else
181 clear_IF(env);
182 return 0;
183 }
184
185 static inline unsigned int get_vflags(CPUX86State *env)
186 {
187 TaskState *ts = env->opaque;
188 unsigned int flags;
189
190 flags = env->eflags & RETURN_MASK;
191 if (ts->v86flags & VIF_MASK)
192 flags |= IF_MASK;
193 flags |= IOPL_MASK;
194 return flags | (ts->v86flags & ts->v86mask);
195 }
196
197 #define ADD16(reg, val) reg = (reg & ~0xffff) | ((reg + (val)) & 0xffff)
198
199 /* handle VM86 interrupt (NOTE: the CPU core currently does not
200 support TSS interrupt revectoring, so this code is always executed) */
201 static void do_int(CPUX86State *env, int intno)
202 {
203 TaskState *ts = env->opaque;
204 uint32_t int_addr, segoffs, ssp;
205 unsigned int sp;
206
207 if (env->segs[R_CS].selector == TARGET_BIOSSEG)
208 goto cannot_handle;
209 if (is_revectored(intno, &ts->vm86plus.int_revectored))
210 goto cannot_handle;
211 if (intno == 0x21 && is_revectored((env->regs[R_EAX] >> 8) & 0xff,
212 &ts->vm86plus.int21_revectored))
213 goto cannot_handle;
214 int_addr = (intno << 2);
215 segoffs = ldl(int_addr);
216 if ((segoffs >> 16) == TARGET_BIOSSEG)
217 goto cannot_handle;
218 #if defined(DEBUG_VM86)
219 fprintf(logfile, "VM86: emulating int 0x%x. CS:IP=%04x:%04x\n",
220 intno, segoffs >> 16, segoffs & 0xffff);
221 #endif
222 /* save old state */
223 ssp = env->segs[R_SS].selector << 4;
224 sp = env->regs[R_ESP] & 0xffff;
225 vm_putw(ssp, sp - 2, get_vflags(env));
226 vm_putw(ssp, sp - 4, env->segs[R_CS].selector);
227 vm_putw(ssp, sp - 6, env->eip);
228 ADD16(env->regs[R_ESP], -6);
229 /* goto interrupt handler */
230 env->eip = segoffs & 0xffff;
231 cpu_x86_load_seg(env, R_CS, segoffs >> 16);
232 clear_TF(env);
233 clear_IF(env);
234 clear_AC(env);
235 return;
236 cannot_handle:
237 #if defined(DEBUG_VM86)
238 fprintf(logfile, "VM86: return to 32 bits int 0x%x\n", intno);
239 #endif
240 return_to_32bit(env, TARGET_VM86_INTx | (intno << 8));
241 }
242
243 void handle_vm86_trap(CPUX86State *env, int trapno)
244 {
245 if (trapno == 1 || trapno == 3) {
246 return_to_32bit(env, TARGET_VM86_TRAP + (trapno << 8));
247 } else {
248 do_int(env, trapno);
249 }
250 }
251
252 #define CHECK_IF_IN_TRAP() \
253 if ((ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) && \
254 (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_TFpendig)) \
255 newflags |= TF_MASK
256
257 #define VM86_FAULT_RETURN \
258 if ((ts->vm86plus.vm86plus.flags & TARGET_force_return_for_pic) && \
259 (ts->v86flags & (IF_MASK | VIF_MASK))) \
260 return_to_32bit(env, TARGET_VM86_PICRETURN); \
261 return
262
263 void handle_vm86_fault(CPUX86State *env)
264 {
265 TaskState *ts = env->opaque;
266 uint32_t csp, ssp;
267 unsigned int ip, sp, newflags, newip, newcs, opcode, intno;
268 int data32, pref_done;
269
270 csp = env->segs[R_CS].selector << 4;
271 ip = env->eip & 0xffff;
272
273 ssp = env->segs[R_SS].selector << 4;
274 sp = env->regs[R_ESP] & 0xffff;
275
276 #if defined(DEBUG_VM86)
277 fprintf(logfile, "VM86 exception %04x:%08x\n",
278 env->segs[R_CS].selector, env->eip);
279 #endif
280
281 data32 = 0;
282 pref_done = 0;
283 do {
284 opcode = vm_getb(csp, ip);
285 ADD16(ip, 1);
286 switch (opcode) {
287 case 0x66: /* 32-bit data */ data32=1; break;
288 case 0x67: /* 32-bit address */ break;
289 case 0x2e: /* CS */ break;
290 case 0x3e: /* DS */ break;
291 case 0x26: /* ES */ break;
292 case 0x36: /* SS */ break;
293 case 0x65: /* GS */ break;
294 case 0x64: /* FS */ break;
295 case 0xf2: /* repnz */ break;
296 case 0xf3: /* rep */ break;
297 default: pref_done = 1;
298 }
299 } while (!pref_done);
300
301 /* VM86 mode */
302 switch(opcode) {
303 case 0x9c: /* pushf */
304 if (data32) {
305 vm_putl(ssp, sp - 4, get_vflags(env));
306 ADD16(env->regs[R_ESP], -4);
307 } else {
308 vm_putw(ssp, sp - 2, get_vflags(env));
309 ADD16(env->regs[R_ESP], -2);
310 }
311 env->eip = ip;
312 VM86_FAULT_RETURN;
313
314 case 0x9d: /* popf */
315 if (data32) {
316 newflags = vm_getl(ssp, sp);
317 ADD16(env->regs[R_ESP], 4);
318 } else {
319 newflags = vm_getw(ssp, sp);
320 ADD16(env->regs[R_ESP], 2);
321 }
322 env->eip = ip;
323 CHECK_IF_IN_TRAP();
324 if (data32) {
325 if (set_vflags_long(newflags, env))
326 return;
327 } else {
328 if (set_vflags_short(newflags, env))
329 return;
330 }
331 VM86_FAULT_RETURN;
332
333 case 0xcd: /* int */
334 intno = vm_getb(csp, ip);
335 ADD16(ip, 1);
336 env->eip = ip;
337 if (ts->vm86plus.vm86plus.flags & TARGET_vm86dbg_active) {
338 if ( (ts->vm86plus.vm86plus.vm86dbg_intxxtab[intno >> 3] >>
339 (intno &7)) & 1) {
340 return_to_32bit(env, TARGET_VM86_INTx + (intno << 8));
341 return;
342 }
343 }
344 do_int(env, intno);
345 break;
346
347 case 0xcf: /* iret */
348 if (data32) {
349 newip = vm_getl(ssp, sp) & 0xffff;
350 newcs = vm_getl(ssp, sp + 4) & 0xffff;
351 newflags = vm_getl(ssp, sp + 8);
352 ADD16(env->regs[R_ESP], 12);
353 } else {
354 newip = vm_getw(ssp, sp);
355 newcs = vm_getw(ssp, sp + 2);
356 newflags = vm_getw(ssp, sp + 4);
357 ADD16(env->regs[R_ESP], 6);
358 }
359 env->eip = newip;
360 cpu_x86_load_seg(env, R_CS, newcs);
361 CHECK_IF_IN_TRAP();
362 if (data32) {
363 if (set_vflags_long(newflags, env))
364 return;
365 } else {
366 if (set_vflags_short(newflags, env))
367 return;
368 }
369 VM86_FAULT_RETURN;
370
371 case 0xfa: /* cli */
372 env->eip = ip;
373 clear_IF(env);
374 VM86_FAULT_RETURN;
375
376 case 0xfb: /* sti */
377 env->eip = ip;
378 if (set_IF(env))
379 return;
380 VM86_FAULT_RETURN;
381
382 default:
383 /* real VM86 GPF exception */
384 return_to_32bit(env, TARGET_VM86_UNKNOWN);
385 break;
386 }
387 }
388
389 int do_vm86(CPUX86State *env, long subfunction, abi_ulong vm86_addr)
390 {
391 TaskState *ts = env->opaque;
392 struct target_vm86plus_struct * target_v86;
393 int ret;
394
395 switch (subfunction) {
396 case TARGET_VM86_REQUEST_IRQ:
397 case TARGET_VM86_FREE_IRQ:
398 case TARGET_VM86_GET_IRQ_BITS:
399 case TARGET_VM86_GET_AND_RESET_IRQ:
400 gemu_log("qemu: unsupported vm86 subfunction (%ld)\n", subfunction);
401 ret = -TARGET_EINVAL;
402 goto out;
403 case TARGET_VM86_PLUS_INSTALL_CHECK:
404 /* NOTE: on old vm86 stuff this will return the error
405 from verify_area(), because the subfunction is
406 interpreted as (invalid) address to vm86_struct.
407 So the installation check works.
408 */
409 ret = 0;
410 goto out;
411 }
412
413 /* save current CPU regs */
414 ts->vm86_saved_regs.eax = 0; /* default vm86 syscall return code */
415 ts->vm86_saved_regs.ebx = env->regs[R_EBX];
416 ts->vm86_saved_regs.ecx = env->regs[R_ECX];
417 ts->vm86_saved_regs.edx = env->regs[R_EDX];
418 ts->vm86_saved_regs.esi = env->regs[R_ESI];
419 ts->vm86_saved_regs.edi = env->regs[R_EDI];
420 ts->vm86_saved_regs.ebp = env->regs[R_EBP];
421 ts->vm86_saved_regs.esp = env->regs[R_ESP];
422 ts->vm86_saved_regs.eflags = env->eflags;
423 ts->vm86_saved_regs.eip = env->eip;
424 ts->vm86_saved_regs.cs = env->segs[R_CS].selector;
425 ts->vm86_saved_regs.ss = env->segs[R_SS].selector;
426 ts->vm86_saved_regs.ds = env->segs[R_DS].selector;
427 ts->vm86_saved_regs.es = env->segs[R_ES].selector;
428 ts->vm86_saved_regs.fs = env->segs[R_FS].selector;
429 ts->vm86_saved_regs.gs = env->segs[R_GS].selector;
430
431 ts->target_v86 = vm86_addr;
432 if (!lock_user_struct(VERIFY_READ, target_v86, vm86_addr, 1))
433 return -TARGET_EFAULT;
434 /* build vm86 CPU state */
435 ts->v86flags = tswap32(target_v86->regs.eflags);
436 env->eflags = (env->eflags & ~SAFE_MASK) |
437 (tswap32(target_v86->regs.eflags) & SAFE_MASK) | VM_MASK;
438
439 ts->vm86plus.cpu_type = tswapl(target_v86->cpu_type);
440 switch (ts->vm86plus.cpu_type) {
441 case TARGET_CPU_286:
442 ts->v86mask = 0;
443 break;
444 case TARGET_CPU_386:
445 ts->v86mask = NT_MASK | IOPL_MASK;
446 break;
447 case TARGET_CPU_486:
448 ts->v86mask = AC_MASK | NT_MASK | IOPL_MASK;
449 break;
450 default:
451 ts->v86mask = ID_MASK | AC_MASK | NT_MASK | IOPL_MASK;
452 break;
453 }
454
455 env->regs[R_EBX] = tswap32(target_v86->regs.ebx);
456 env->regs[R_ECX] = tswap32(target_v86->regs.ecx);
457 env->regs[R_EDX] = tswap32(target_v86->regs.edx);
458 env->regs[R_ESI] = tswap32(target_v86->regs.esi);
459 env->regs[R_EDI] = tswap32(target_v86->regs.edi);
460 env->regs[R_EBP] = tswap32(target_v86->regs.ebp);
461 env->regs[R_ESP] = tswap32(target_v86->regs.esp);
462 env->eip = tswap32(target_v86->regs.eip);
463 cpu_x86_load_seg(env, R_CS, tswap16(target_v86->regs.cs));
464 cpu_x86_load_seg(env, R_SS, tswap16(target_v86->regs.ss));
465 cpu_x86_load_seg(env, R_DS, tswap16(target_v86->regs.ds));
466 cpu_x86_load_seg(env, R_ES, tswap16(target_v86->regs.es));
467 cpu_x86_load_seg(env, R_FS, tswap16(target_v86->regs.fs));
468 cpu_x86_load_seg(env, R_GS, tswap16(target_v86->regs.gs));
469 ret = tswap32(target_v86->regs.eax); /* eax will be restored at
470 the end of the syscall */
471 memcpy(&ts->vm86plus.int_revectored,
472 &target_v86->int_revectored, 32);
473 memcpy(&ts->vm86plus.int21_revectored,
474 &target_v86->int21_revectored, 32);
475 ts->vm86plus.vm86plus.flags = tswapl(target_v86->vm86plus.flags);
476 memcpy(&ts->vm86plus.vm86plus.vm86dbg_intxxtab,
477 target_v86->vm86plus.vm86dbg_intxxtab, 32);
478 unlock_user_struct(target_v86, vm86_addr, 0);
479
480 #ifdef DEBUG_VM86
481 fprintf(logfile, "do_vm86: cs:ip=%04x:%04x\n",
482 env->segs[R_CS].selector, env->eip);
483 #endif
484 /* now the virtual CPU is ready for vm86 execution ! */
485 out:
486 return ret;
487 }
488
Stable branch of Qemu 0.9.1