FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/vm86.c
1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1997 Jonathan Lemon
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/priv.h>
35 #include <sys/proc.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39
40 #include <vm/vm.h>
41 #include <vm/pmap.h>
42 #include <vm/vm_map.h>
43 #include <vm/vm_page.h>
44
45 #include <machine/md_var.h>
46 #include <machine/pcb.h>
47 #include <machine/pcb_ext.h>
48 #include <machine/psl.h>
49 #include <machine/specialreg.h>
50 #include <machine/sysarch.h>
51
52 extern int vm86pa;
53 extern struct pcb *vm86pcb;
54
55 static struct mtx vm86_lock;
56
57 extern int vm86_bioscall(struct vm86frame *);
58 extern void vm86_biosret(struct vm86frame *);
59
60 void vm86_prepcall(struct vm86frame *);
61
62 struct system_map {
63 int type;
64 vm_offset_t start;
65 vm_offset_t end;
66 };
67
68 #define HLT 0xf4
69 #define CLI 0xfa
70 #define STI 0xfb
71 #define PUSHF 0x9c
72 #define POPF 0x9d
73 #define INTn 0xcd
74 #define IRET 0xcf
75 #define CALLm 0xff
76 #define OPERAND_SIZE_PREFIX 0x66
77 #define ADDRESS_SIZE_PREFIX 0x67
78 #define PUSH_MASK ~(PSL_VM | PSL_RF | PSL_I)
79 #define POP_MASK ~(PSL_VIP | PSL_VIF | PSL_VM | PSL_RF | PSL_IOPL)
80
81 static int
82 vm86_suword16(volatile void *base, int word)
83 {
84
85 if (curthread->td_critnest != 0) {
86 *(volatile uint16_t *)base = word;
87 return (0);
88 }
89 return (suword16(base, word));
90 }
91
92 static int
93 vm86_suword(volatile void *base, long word)
94 {
95
96 if (curthread->td_critnest != 0) {
97 *(volatile long *)base = word;
98 return (0);
99 }
100 return (suword(base, word));
101 }
102
103 static int
104 vm86_fubyte(volatile const void *base)
105 {
106
107 if (curthread->td_critnest != 0)
108 return (*(volatile const u_char *)base);
109 return (fubyte(base));
110 }
111
112 static int
113 vm86_fuword16(volatile const void *base)
114 {
115
116 if (curthread->td_critnest != 0)
117 return (*(volatile const uint16_t *)base);
118 return (fuword16(base));
119 }
120
121 static long
122 vm86_fuword(volatile const void *base)
123 {
124
125 if (curthread->td_critnest != 0)
126 return (*(volatile const long *)base);
127 return (fuword(base));
128 }
129
130 static __inline caddr_t
131 MAKE_ADDR(u_short sel, u_short off)
132 {
133 return ((caddr_t)((sel << 4) + off));
134 }
135
136 static __inline void
137 GET_VEC(u_int vec, u_short *sel, u_short *off)
138 {
139 *sel = vec >> 16;
140 *off = vec & 0xffff;
141 }
142
143 static __inline u_int
144 MAKE_VEC(u_short sel, u_short off)
145 {
146 return ((sel << 16) | off);
147 }
148
149 static __inline void
150 PUSH(u_short x, struct vm86frame *vmf)
151 {
152 vmf->vmf_sp -= 2;
153 vm86_suword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
154 }
155
156 static __inline void
157 PUSHL(u_int x, struct vm86frame *vmf)
158 {
159 vmf->vmf_sp -= 4;
160 vm86_suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
161 }
162
163 static __inline u_short
164 POP(struct vm86frame *vmf)
165 {
166 u_short x = vm86_fuword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
167
168 vmf->vmf_sp += 2;
169 return (x);
170 }
171
172 static __inline u_int
173 POPL(struct vm86frame *vmf)
174 {
175 u_int x = vm86_fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
176
177 vmf->vmf_sp += 4;
178 return (x);
179 }
180
181 int
182 vm86_emulate(struct vm86frame *vmf)
183 {
184 struct vm86_kernel *vm86;
185 caddr_t addr;
186 u_char i_byte;
187 u_int temp_flags;
188 int inc_ip = 1;
189 int retcode = 0;
190
191 /*
192 * pcb_ext contains the address of the extension area, or zero if
193 * the extension is not present. (This check should not be needed,
194 * as we can't enter vm86 mode until we set up an extension area)
195 */
196 if (curpcb->pcb_ext == 0)
197 return (SIGBUS);
198 vm86 = &curpcb->pcb_ext->ext_vm86;
199
200 if (vmf->vmf_eflags & PSL_T)
201 retcode = SIGTRAP;
202
203 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
204 i_byte = vm86_fubyte(addr);
205 if (i_byte == ADDRESS_SIZE_PREFIX) {
206 i_byte = vm86_fubyte(++addr);
207 inc_ip++;
208 }
209
210 if (vm86->vm86_has_vme) {
211 switch (i_byte) {
212 case OPERAND_SIZE_PREFIX:
213 i_byte = vm86_fubyte(++addr);
214 inc_ip++;
215 switch (i_byte) {
216 case PUSHF:
217 if (vmf->vmf_eflags & PSL_VIF)
218 PUSHL((vmf->vmf_eflags & PUSH_MASK)
219 | PSL_IOPL | PSL_I, vmf);
220 else
221 PUSHL((vmf->vmf_eflags & PUSH_MASK)
222 | PSL_IOPL, vmf);
223 vmf->vmf_ip += inc_ip;
224 return (retcode);
225
226 case POPF:
227 temp_flags = POPL(vmf) & POP_MASK;
228 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
229 | temp_flags | PSL_VM | PSL_I;
230 vmf->vmf_ip += inc_ip;
231 if (temp_flags & PSL_I) {
232 vmf->vmf_eflags |= PSL_VIF;
233 if (vmf->vmf_eflags & PSL_VIP)
234 break;
235 } else {
236 vmf->vmf_eflags &= ~PSL_VIF;
237 }
238 return (retcode);
239 }
240 break;
241
242 /* VME faults here if VIP is set, but does not set VIF. */
243 case STI:
244 vmf->vmf_eflags |= PSL_VIF;
245 vmf->vmf_ip += inc_ip;
246 if ((vmf->vmf_eflags & PSL_VIP) == 0) {
247 uprintf("fatal sti\n");
248 return (SIGKILL);
249 }
250 break;
251
252 /* VME if no redirection support */
253 case INTn:
254 break;
255
256 /* VME if trying to set PSL_T, or PSL_I when VIP is set */
257 case POPF:
258 temp_flags = POP(vmf) & POP_MASK;
259 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
260 | temp_flags | PSL_VM | PSL_I;
261 vmf->vmf_ip += inc_ip;
262 if (temp_flags & PSL_I) {
263 vmf->vmf_eflags |= PSL_VIF;
264 if (vmf->vmf_eflags & PSL_VIP)
265 break;
266 } else {
267 vmf->vmf_eflags &= ~PSL_VIF;
268 }
269 return (retcode);
270
271 /* VME if trying to set PSL_T, or PSL_I when VIP is set */
272 case IRET:
273 vmf->vmf_ip = POP(vmf);
274 vmf->vmf_cs = POP(vmf);
275 temp_flags = POP(vmf) & POP_MASK;
276 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
277 | temp_flags | PSL_VM | PSL_I;
278 if (temp_flags & PSL_I) {
279 vmf->vmf_eflags |= PSL_VIF;
280 if (vmf->vmf_eflags & PSL_VIP)
281 break;
282 } else {
283 vmf->vmf_eflags &= ~PSL_VIF;
284 }
285 return (retcode);
286 }
287 return (SIGBUS);
288 }
289
290 switch (i_byte) {
291 case OPERAND_SIZE_PREFIX:
292 i_byte = vm86_fubyte(++addr);
293 inc_ip++;
294 switch (i_byte) {
295 case PUSHF:
296 if (vm86->vm86_eflags & PSL_VIF)
297 PUSHL((vmf->vmf_flags & PUSH_MASK)
298 | PSL_IOPL | PSL_I, vmf);
299 else
300 PUSHL((vmf->vmf_flags & PUSH_MASK)
301 | PSL_IOPL, vmf);
302 vmf->vmf_ip += inc_ip;
303 return (retcode);
304
305 case POPF:
306 temp_flags = POPL(vmf) & POP_MASK;
307 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
308 | temp_flags | PSL_VM | PSL_I;
309 vmf->vmf_ip += inc_ip;
310 if (temp_flags & PSL_I) {
311 vm86->vm86_eflags |= PSL_VIF;
312 if (vm86->vm86_eflags & PSL_VIP)
313 break;
314 } else {
315 vm86->vm86_eflags &= ~PSL_VIF;
316 }
317 return (retcode);
318 }
319 return (SIGBUS);
320
321 case CLI:
322 vm86->vm86_eflags &= ~PSL_VIF;
323 vmf->vmf_ip += inc_ip;
324 return (retcode);
325
326 case STI:
327 /* if there is a pending interrupt, go to the emulator */
328 vm86->vm86_eflags |= PSL_VIF;
329 vmf->vmf_ip += inc_ip;
330 if (vm86->vm86_eflags & PSL_VIP)
331 break;
332 return (retcode);
333
334 case PUSHF:
335 if (vm86->vm86_eflags & PSL_VIF)
336 PUSH((vmf->vmf_flags & PUSH_MASK)
337 | PSL_IOPL | PSL_I, vmf);
338 else
339 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
340 vmf->vmf_ip += inc_ip;
341 return (retcode);
342
343 case INTn:
344 i_byte = vm86_fubyte(addr + 1);
345 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
346 break;
347 if (vm86->vm86_eflags & PSL_VIF)
348 PUSH((vmf->vmf_flags & PUSH_MASK)
349 | PSL_IOPL | PSL_I, vmf);
350 else
351 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
352 PUSH(vmf->vmf_cs, vmf);
353 PUSH(vmf->vmf_ip + inc_ip + 1, vmf); /* increment IP */
354 GET_VEC(vm86_fuword((caddr_t)(i_byte * 4)),
355 &vmf->vmf_cs, &vmf->vmf_ip);
356 vmf->vmf_flags &= ~PSL_T;
357 vm86->vm86_eflags &= ~PSL_VIF;
358 return (retcode);
359
360 case IRET:
361 vmf->vmf_ip = POP(vmf);
362 vmf->vmf_cs = POP(vmf);
363 temp_flags = POP(vmf) & POP_MASK;
364 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
365 | temp_flags | PSL_VM | PSL_I;
366 if (temp_flags & PSL_I) {
367 vm86->vm86_eflags |= PSL_VIF;
368 if (vm86->vm86_eflags & PSL_VIP)
369 break;
370 } else {
371 vm86->vm86_eflags &= ~PSL_VIF;
372 }
373 return (retcode);
374
375 case POPF:
376 temp_flags = POP(vmf) & POP_MASK;
377 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
378 | temp_flags | PSL_VM | PSL_I;
379 vmf->vmf_ip += inc_ip;
380 if (temp_flags & PSL_I) {
381 vm86->vm86_eflags |= PSL_VIF;
382 if (vm86->vm86_eflags & PSL_VIP)
383 break;
384 } else {
385 vm86->vm86_eflags &= ~PSL_VIF;
386 }
387 return (retcode);
388 }
389 return (SIGBUS);
390 }
391
392 #define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE)
393 #define INTMAP_SIZE 32
394 #define IOMAP_SIZE ctob(IOPAGES)
395 #define TSS_SIZE \
396 (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
397 INTMAP_SIZE + IOMAP_SIZE + 1)
398
399 struct vm86_layout_pae {
400 uint64_t vml_pgtbl[PGTABLE_SIZE];
401 struct pcb vml_pcb;
402 struct pcb_ext vml_ext;
403 char vml_intmap[INTMAP_SIZE];
404 char vml_iomap[IOMAP_SIZE];
405 char vml_iomap_trailer;
406 };
407
408 struct vm86_layout_nopae {
409 uint32_t vml_pgtbl[PGTABLE_SIZE];
410 struct pcb vml_pcb;
411 struct pcb_ext vml_ext;
412 char vml_intmap[INTMAP_SIZE];
413 char vml_iomap[IOMAP_SIZE];
414 char vml_iomap_trailer;
415 };
416
417 _Static_assert(sizeof(struct vm86_layout_pae) <= ctob(3),
418 "struct vm86_layout_pae exceeds space allocated in locore.s");
419 _Static_assert(sizeof(struct vm86_layout_nopae) <= ctob(3),
420 "struct vm86_layout_nopae exceeds space allocated in locore.s");
421
422 static void
423 vm86_initialize_pae(void)
424 {
425 int i;
426 u_int *addr;
427 struct vm86_layout_pae *vml;
428 struct pcb *pcb;
429 struct pcb_ext *ext;
430 struct soft_segment_descriptor ssd = {
431 0, /* segment base address (overwritten) */
432 0, /* length (overwritten) */
433 SDT_SYS386TSS, /* segment type */
434 0, /* priority level */
435 1, /* descriptor present */
436 0, 0,
437 0, /* default 16 size */
438 0 /* granularity */
439 };
440
441 /*
442 * Below is the memory layout that we use for the vm86 region.
443 *
444 * +--------+
445 * | |
446 * | |
447 * | page 0 |
448 * | | +--------+
449 * | | | stack |
450 * +--------+ +--------+ <--------- vm86paddr
451 * | | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
452 * | | +--------+
453 * | | | PCB | size: ~240 bytes
454 * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
455 * | | +--------+
456 * | | |int map |
457 * | | +--------+
458 * +--------+ | |
459 * | page 2 | | I/O |
460 * +--------+ | bitmap |
461 * | page 3 | | |
462 * | | +--------+
463 * +--------+
464 */
465
466 /*
467 * A rudimentary PCB must be installed, in order to get to the
468 * PCB extension area. We use the PCB area as a scratchpad for
469 * data storage, the layout of which is shown below.
470 *
471 * pcb_esi = new PTD entry 0
472 * pcb_ebp = pointer to frame on vm86 stack
473 * pcb_esp = stack frame pointer at time of switch
474 * pcb_ebx = va of vm86 page table
475 * pcb_eip = argument pointer to initial call
476 * pcb_vm86[0] = saved TSS descriptor, word 0
477 * pcb_vm86[1] = saved TSS descriptor, word 1
478 */
479 #define new_ptd pcb_esi
480 #define vm86_frame pcb_ebp
481 #define pgtable_va pcb_ebx
482
483 vml = (struct vm86_layout_pae *)vm86paddr;
484 pcb = &vml->vml_pcb;
485 ext = &vml->vml_ext;
486
487 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF);
488
489 bzero(pcb, sizeof(struct pcb));
490 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
491 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
492 pcb->pgtable_va = vm86paddr;
493 pcb->pcb_flags = PCB_VM86CALL;
494 pcb->pcb_ext = ext;
495
496 bzero(ext, sizeof(struct pcb_ext));
497 ext->ext_tss.tss_esp0 = vm86paddr;
498 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
499 ext->ext_tss.tss_ioopt =
500 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
501 ext->ext_iomap = vml->vml_iomap;
502 ext->ext_vm86.vm86_intmap = vml->vml_intmap;
503
504 if (cpu_feature & CPUID_VME)
505 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
506
507 addr = (u_int *)ext->ext_vm86.vm86_intmap;
508 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
509 *addr++ = 0;
510 vml->vml_iomap_trailer = 0xff;
511
512 ssd.ssd_base = (u_int)&ext->ext_tss;
513 ssd.ssd_limit = TSS_SIZE - 1;
514 ssdtosd(&ssd, &ext->ext_tssd);
515
516 vm86pcb = pcb;
517
518 #if 0
519 /*
520 * use whatever is leftover of the vm86 page layout as a
521 * message buffer so we can capture early output.
522 */
523 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
524 ctob(3) - sizeof(struct vm86_layout));
525 #endif
526 }
527
528 static void
529 vm86_initialize_nopae(void)
530 {
531 int i;
532 u_int *addr;
533 struct vm86_layout_nopae *vml;
534 struct pcb *pcb;
535 struct pcb_ext *ext;
536 struct soft_segment_descriptor ssd = {
537 0, /* segment base address (overwritten) */
538 0, /* length (overwritten) */
539 SDT_SYS386TSS, /* segment type */
540 0, /* priority level */
541 1, /* descriptor present */
542 0, 0,
543 0, /* default 16 size */
544 0 /* granularity */
545 };
546
547 vml = (struct vm86_layout_nopae *)vm86paddr;
548 pcb = &vml->vml_pcb;
549 ext = &vml->vml_ext;
550
551 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF);
552
553 bzero(pcb, sizeof(struct pcb));
554 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
555 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
556 pcb->pgtable_va = vm86paddr;
557 pcb->pcb_flags = PCB_VM86CALL;
558 pcb->pcb_ext = ext;
559
560 bzero(ext, sizeof(struct pcb_ext));
561 ext->ext_tss.tss_esp0 = vm86paddr;
562 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
563 ext->ext_tss.tss_ioopt =
564 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
565 ext->ext_iomap = vml->vml_iomap;
566 ext->ext_vm86.vm86_intmap = vml->vml_intmap;
567
568 if (cpu_feature & CPUID_VME)
569 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
570
571 addr = (u_int *)ext->ext_vm86.vm86_intmap;
572 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
573 *addr++ = 0;
574 vml->vml_iomap_trailer = 0xff;
575
576 ssd.ssd_base = (u_int)&ext->ext_tss;
577 ssd.ssd_limit = TSS_SIZE - 1;
578 ssdtosd(&ssd, &ext->ext_tssd);
579
580 vm86pcb = pcb;
581
582 #if 0
583 /*
584 * use whatever is leftover of the vm86 page layout as a
585 * message buffer so we can capture early output.
586 */
587 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
588 ctob(3) - sizeof(struct vm86_layout));
589 #endif
590 }
591
592 void
593 vm86_initialize(void)
594 {
595
596 if (pae_mode)
597 vm86_initialize_pae();
598 else
599 vm86_initialize_nopae();
600 }
601
602 vm_offset_t
603 vm86_getpage(struct vm86context *vmc, int pagenum)
604 {
605 int i;
606
607 for (i = 0; i < vmc->npages; i++)
608 if (vmc->pmap[i].pte_num == pagenum)
609 return (vmc->pmap[i].kva);
610 return (0);
611 }
612
613 vm_offset_t
614 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
615 {
616 int i, flags = 0;
617
618 for (i = 0; i < vmc->npages; i++)
619 if (vmc->pmap[i].pte_num == pagenum)
620 goto overlap;
621
622 if (vmc->npages == VM86_PMAPSIZE)
623 goto full; /* XXX grow map? */
624
625 if (kva == 0) {
626 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
627 flags = VMAP_MALLOC;
628 }
629
630 i = vmc->npages++;
631 vmc->pmap[i].flags = flags;
632 vmc->pmap[i].kva = kva;
633 vmc->pmap[i].pte_num = pagenum;
634 return (kva);
635 overlap:
636 panic("vm86_addpage: overlap");
637 full:
638 panic("vm86_addpage: not enough room");
639 }
640
641 /*
642 * called from vm86_bioscall, while in vm86 address space, to finalize setup.
643 */
644 void
645 vm86_prepcall(struct vm86frame *vmf)
646 {
647 struct vm86_kernel *vm86;
648 uint32_t *stack;
649 uint8_t *code;
650
651 code = (void *)0xa00;
652 stack = (void *)(0x1000 - 2); /* keep aligned */
653 if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) {
654 /* interrupt call requested */
655 code[0] = INTn;
656 code[1] = vmf->vmf_trapno & 0xff;
657 code[2] = HLT;
658 vmf->vmf_ip = (uintptr_t)code;
659 vmf->vmf_cs = 0;
660 } else {
661 code[0] = HLT;
662 stack--;
663 stack[0] = MAKE_VEC(0, (uintptr_t)code);
664 }
665 vmf->vmf_sp = (uintptr_t)stack;
666 vmf->vmf_ss = 0;
667 vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = 0;
668 vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
669
670 vm86 = &curpcb->pcb_ext->ext_vm86;
671 if (!vm86->vm86_has_vme)
672 vm86->vm86_eflags = vmf->vmf_eflags; /* save VIF, VIP */
673 }
674
675 /*
676 * vm86 trap handler; determines whether routine succeeded or not.
677 * Called while in vm86 space, returns to calling process.
678 */
679 void
680 vm86_trap(struct vm86frame *vmf)
681 {
682 void (*p)(struct vm86frame *);
683 caddr_t addr;
684
685 /* "should not happen" */
686 if ((vmf->vmf_eflags & PSL_VM) == 0)
687 panic("vm86_trap called, but not in vm86 mode");
688
689 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
690 if (*(u_char *)addr == HLT)
691 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
692 else
693 vmf->vmf_trapno = vmf->vmf_trapno << 16;
694
695 p = (void (*)(struct vm86frame *))((uintptr_t)vm86_biosret +
696 setidt_disp);
697 p(vmf);
698 }
699
700 int
701 vm86_intcall(int intnum, struct vm86frame *vmf)
702 {
703 int (*p)(struct vm86frame *);
704 int retval;
705
706 if (intnum < 0 || intnum > 0xff)
707 return (EINVAL);
708
709 vmf->vmf_trapno = intnum;
710 p = (int (*)(struct vm86frame *))((uintptr_t)vm86_bioscall +
711 setidt_disp);
712 mtx_lock(&vm86_lock);
713 critical_enter();
714 retval = p(vmf);
715 critical_exit();
716 mtx_unlock(&vm86_lock);
717 return (retval);
718 }
719
720 /*
721 * struct vm86context contains the page table to use when making
722 * vm86 calls. If intnum is a valid interrupt number (0-255), then
723 * the "interrupt trampoline" will be used, otherwise we use the
724 * caller's cs:ip routine.
725 */
726 int
727 vm86_datacall(int intnum, struct vm86frame *vmf, struct vm86context *vmc)
728 {
729 uint64_t *pte_pae;
730 uint32_t *pte_nopae;
731 int (*p)(struct vm86frame *);
732 vm_paddr_t page;
733 int i, entry, retval;
734
735 mtx_lock(&vm86_lock);
736 if (pae_mode) {
737 pte_pae = (uint64_t *)vm86paddr;
738 for (i = 0; i < vmc->npages; i++) {
739 page = vtophys(vmc->pmap[i].kva & PG_FRAME_PAE);
740 entry = vmc->pmap[i].pte_num;
741 vmc->pmap[i].old_pte = pte_pae[entry];
742 pte_pae[entry] = page | PG_V | PG_RW | PG_U;
743 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
744 }
745 } else {
746 pte_nopae = (uint32_t *)vm86paddr;
747 for (i = 0; i < vmc->npages; i++) {
748 page = vtophys(vmc->pmap[i].kva & PG_FRAME_NOPAE);
749 entry = vmc->pmap[i].pte_num;
750 vmc->pmap[i].old_pte = pte_nopae[entry];
751 pte_nopae[entry] = page | PG_V | PG_RW | PG_U;
752 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
753 }
754 }
755
756 vmf->vmf_trapno = intnum;
757 p = (int (*)(struct vm86frame *))((uintptr_t)vm86_bioscall +
758 setidt_disp);
759 critical_enter();
760 retval = p(vmf);
761 critical_exit();
762
763 if (pae_mode) {
764 for (i = 0; i < vmc->npages; i++) {
765 entry = vmc->pmap[i].pte_num;
766 pte_pae[entry] = vmc->pmap[i].old_pte;
767 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
768 }
769 } else {
770 for (i = 0; i < vmc->npages; i++) {
771 entry = vmc->pmap[i].pte_num;
772 pte_nopae[entry] = vmc->pmap[i].old_pte;
773 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
774 }
775 }
776 mtx_unlock(&vm86_lock);
777
778 return (retval);
779 }
780
781 vm_offset_t
782 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off)
783 {
784 int i, page;
785 vm_offset_t addr;
786
787 addr = (vm_offset_t)MAKE_ADDR(sel, off);
788 page = addr >> PAGE_SHIFT;
789 for (i = 0; i < vmc->npages; i++)
790 if (page == vmc->pmap[i].pte_num)
791 return (vmc->pmap[i].kva + (addr & PAGE_MASK));
792 return (0);
793 }
794
795 int
796 vm86_getptr(struct vm86context *vmc, vm_offset_t kva, u_short *sel,
797 u_short *off)
798 {
799 int i;
800
801 for (i = 0; i < vmc->npages; i++)
802 if (kva >= vmc->pmap[i].kva &&
803 kva < vmc->pmap[i].kva + PAGE_SIZE) {
804 *off = kva - vmc->pmap[i].kva;
805 *sel = vmc->pmap[i].pte_num << 8;
806 return (1);
807 }
808 return (0);
809 }
810
811 int
812 vm86_sysarch(struct thread *td, char *args)
813 {
814 int error = 0;
815 struct i386_vm86_args ua;
816 struct vm86_kernel *vm86;
817
818 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
819 return (error);
820
821 if (td->td_pcb->pcb_ext == 0)
822 if ((error = i386_extend_pcb(td)) != 0)
823 return (error);
824 vm86 = &td->td_pcb->pcb_ext->ext_vm86;
825
826 switch (ua.sub_op) {
827 case VM86_INIT: {
828 struct vm86_init_args sa;
829
830 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
831 return (error);
832 if (cpu_feature & CPUID_VME)
833 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
834 else
835 vm86->vm86_has_vme = 0;
836 vm86->vm86_inited = 1;
837 vm86->vm86_debug = sa.debug;
838 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
839 }
840 break;
841
842 #if 0
843 case VM86_SET_VME: {
844 struct vm86_vme_args sa;
845
846 if ((cpu_feature & CPUID_VME) == 0)
847 return (ENODEV);
848
849 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
850 return (error);
851 if (sa.state)
852 load_cr4(rcr4() | CR4_VME);
853 else
854 load_cr4(rcr4() & ~CR4_VME);
855 }
856 break;
857 #endif
858
859 case VM86_GET_VME: {
860 struct vm86_vme_args sa;
861
862 sa.state = (rcr4() & CR4_VME ? 1 : 0);
863 error = copyout(&sa, ua.sub_args, sizeof(sa));
864 }
865 break;
866
867 case VM86_INTCALL: {
868 struct vm86_intcall_args sa;
869
870 if ((error = priv_check(td, PRIV_VM86_INTCALL)))
871 return (error);
872 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
873 return (error);
874 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
875 return (error);
876 error = copyout(&sa, ua.sub_args, sizeof(sa));
877 }
878 break;
879
880 default:
881 error = EINVAL;
882 }
883 return (error);
884 }
Cache object: 4a702da4c6ed19b155161d1017b0cee2
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