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