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 __inline caddr_t
  82 MAKE_ADDR(u_short sel, u_short off)
  83 {
  84         return ((caddr_t)((sel << 4) + off));
  85 }
  86
  87 static __inline void
  88 GET_VEC(u_int vec, u_short *sel, u_short *off)
  89 {
  90         *sel = vec >> 16;
  91         *off = vec & 0xffff;
  92 }
  93
  94 static __inline u_int
  95 MAKE_VEC(u_short sel, u_short off)
  96 {
  97         return ((sel << 16) | off);
  98 }
  99
 100 static __inline void
 101 PUSH(u_short x, struct vm86frame *vmf)
 102 {
 103         vmf->vmf_sp -= 2;
 104         suword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 105 }
 106
 107 static __inline void
 108 PUSHL(u_int x, struct vm86frame *vmf)
 109 {
 110         vmf->vmf_sp -= 4;
 111         suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 112 }
 113
 114 static __inline u_short
 115 POP(struct vm86frame *vmf)
 116 {
 117         u_short x = fuword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 118
 119         vmf->vmf_sp += 2;
 120         return (x);
 121 }
 122
 123 static __inline u_int
 124 POPL(struct vm86frame *vmf)
 125 {
 126         u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 127
 128         vmf->vmf_sp += 4;
 129         return (x);
 130 }
 131
 132 int
 133 vm86_emulate(struct vm86frame *vmf)
 134 {
 135         struct vm86_kernel *vm86;
 136         caddr_t addr;
 137         u_char i_byte;
 138         u_int temp_flags;
 139         int inc_ip = 1;
 140         int retcode = 0;
 141
 142         /*
 143          * pcb_ext contains the address of the extension area, or zero if
 144          * the extension is not present.  (This check should not be needed,
 145          * as we can't enter vm86 mode until we set up an extension area)
 146          */
 147         if (curpcb->pcb_ext == 0)
 148                 return (SIGBUS);
 149         vm86 = &curpcb->pcb_ext->ext_vm86;
 150
 151         if (vmf->vmf_eflags & PSL_T)
 152                 retcode = SIGTRAP;
 153
 154         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 155         i_byte = fubyte(addr);
 156         if (i_byte == ADDRESS_SIZE_PREFIX) {
 157                 i_byte = fubyte(++addr);
 158                 inc_ip++;
 159         }
 160
 161         if (vm86->vm86_has_vme) {
 162                 switch (i_byte) {
 163                 case OPERAND_SIZE_PREFIX:
 164                         i_byte = fubyte(++addr);
 165                         inc_ip++;
 166                         switch (i_byte) {
 167                         case PUSHF:
 168                                 if (vmf->vmf_eflags & PSL_VIF)
 169                                         PUSHL((vmf->vmf_eflags & PUSH_MASK)
 170                                             | PSL_IOPL | PSL_I, vmf);
 171                                 else
 172                                         PUSHL((vmf->vmf_eflags & PUSH_MASK)
 173                                             | PSL_IOPL, vmf);
 174                                 vmf->vmf_ip += inc_ip;
 175                                 return (retcode);
 176
 177                         case POPF:
 178                                 temp_flags = POPL(vmf) & POP_MASK;
 179                                 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
 180                                     | temp_flags | PSL_VM | PSL_I;
 181                                 vmf->vmf_ip += inc_ip;
 182                                 if (temp_flags & PSL_I) {
 183                                         vmf->vmf_eflags |= PSL_VIF;
 184                                         if (vmf->vmf_eflags & PSL_VIP)
 185                                                 break;
 186                                 } else {
 187                                         vmf->vmf_eflags &= ~PSL_VIF;
 188                                 }
 189                                 return (retcode);
 190                         }
 191                         break;
 192
 193                 /* VME faults here if VIP is set, but does not set VIF. */
 194                 case STI:
 195                         vmf->vmf_eflags |= PSL_VIF;
 196                         vmf->vmf_ip += inc_ip;
 197                         if ((vmf->vmf_eflags & PSL_VIP) == 0) {
 198                                 uprintf("fatal sti\n");
 199                                 return (SIGKILL);
 200                         }
 201                         break;
 202
 203                 /* VME if no redirection support */
 204                 case INTn:
 205                         break;
 206
 207                 /* VME if trying to set PSL_T, or PSL_I when VIP is set */
 208                 case POPF:
 209                         temp_flags = POP(vmf) & POP_MASK;
 210                         vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 211                             | temp_flags | PSL_VM | PSL_I;
 212                         vmf->vmf_ip += inc_ip;
 213                         if (temp_flags & PSL_I) {
 214                                 vmf->vmf_eflags |= PSL_VIF;
 215                                 if (vmf->vmf_eflags & PSL_VIP)
 216                                         break;
 217                         } else {
 218                                 vmf->vmf_eflags &= ~PSL_VIF;
 219                         }
 220                         return (retcode);
 221
 222                 /* VME if trying to set PSL_T, or PSL_I when VIP is set */
 223                 case IRET:
 224                         vmf->vmf_ip = POP(vmf);
 225                         vmf->vmf_cs = POP(vmf);
 226                         temp_flags = POP(vmf) & POP_MASK;
 227                         vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 228                             | temp_flags | PSL_VM | PSL_I;
 229                         if (temp_flags & PSL_I) {
 230                                 vmf->vmf_eflags |= PSL_VIF;
 231                                 if (vmf->vmf_eflags & PSL_VIP)
 232                                         break;
 233                         } else {
 234                                 vmf->vmf_eflags &= ~PSL_VIF;
 235                         }
 236                         return (retcode);
 237
 238                 }
 239                 return (SIGBUS);
 240         }
 241
 242         switch (i_byte) {
 243         case OPERAND_SIZE_PREFIX:
 244                 i_byte = fubyte(++addr);
 245                 inc_ip++;
 246                 switch (i_byte) {
 247                 case PUSHF:
 248                         if (vm86->vm86_eflags & PSL_VIF)
 249                                 PUSHL((vmf->vmf_flags & PUSH_MASK)
 250                                     | PSL_IOPL | PSL_I, vmf);
 251                         else
 252                                 PUSHL((vmf->vmf_flags & PUSH_MASK)
 253                                     | PSL_IOPL, vmf);
 254                         vmf->vmf_ip += inc_ip;
 255                         return (retcode);
 256
 257                 case POPF:
 258                         temp_flags = POPL(vmf) & POP_MASK;
 259                         vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
 260                             | temp_flags | PSL_VM | PSL_I;
 261                         vmf->vmf_ip += inc_ip;
 262                         if (temp_flags & PSL_I) {
 263                                 vm86->vm86_eflags |= PSL_VIF;
 264                                 if (vm86->vm86_eflags & PSL_VIP)
 265                                         break;
 266                         } else {
 267                                 vm86->vm86_eflags &= ~PSL_VIF;
 268                         }
 269                         return (retcode);
 270                 }
 271                 return (SIGBUS);
 272
 273         case CLI:
 274                 vm86->vm86_eflags &= ~PSL_VIF;
 275                 vmf->vmf_ip += inc_ip;
 276                 return (retcode);
 277
 278         case STI:
 279                 /* if there is a pending interrupt, go to the emulator */
 280                 vm86->vm86_eflags |= PSL_VIF;
 281                 vmf->vmf_ip += inc_ip;
 282                 if (vm86->vm86_eflags & PSL_VIP)
 283                         break;
 284                 return (retcode);
 285
 286         case PUSHF:
 287                 if (vm86->vm86_eflags & PSL_VIF)
 288                         PUSH((vmf->vmf_flags & PUSH_MASK)
 289                             | PSL_IOPL | PSL_I, vmf);
 290                 else
 291                         PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
 292                 vmf->vmf_ip += inc_ip;
 293                 return (retcode);
 294
 295         case INTn:
 296                 i_byte = fubyte(addr + 1);
 297                 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
 298                         break;
 299                 if (vm86->vm86_eflags & PSL_VIF)
 300                         PUSH((vmf->vmf_flags & PUSH_MASK)
 301                             | PSL_IOPL | PSL_I, vmf);
 302                 else
 303                         PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
 304                 PUSH(vmf->vmf_cs, vmf);
 305                 PUSH(vmf->vmf_ip + inc_ip + 1, vmf);    /* increment IP */
 306                 GET_VEC(fuword((caddr_t)(i_byte * 4)),
 307                      &vmf->vmf_cs, &vmf->vmf_ip);
 308                 vmf->vmf_flags &= ~PSL_T;
 309                 vm86->vm86_eflags &= ~PSL_VIF;
 310                 return (retcode);
 311
 312         case IRET:
 313                 vmf->vmf_ip = POP(vmf);
 314                 vmf->vmf_cs = POP(vmf);
 315                 temp_flags = POP(vmf) & POP_MASK;
 316                 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 317                     | temp_flags | PSL_VM | PSL_I;
 318                 if (temp_flags & PSL_I) {
 319                         vm86->vm86_eflags |= PSL_VIF;
 320                         if (vm86->vm86_eflags & PSL_VIP)
 321                                 break;
 322                 } else {
 323                         vm86->vm86_eflags &= ~PSL_VIF;
 324                 }
 325                 return (retcode);
 326
 327         case POPF:
 328                 temp_flags = POP(vmf) & POP_MASK;
 329                 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 330                     | temp_flags | PSL_VM | PSL_I;
 331                 vmf->vmf_ip += inc_ip;
 332                 if (temp_flags & PSL_I) {
 333                         vm86->vm86_eflags |= PSL_VIF;
 334                         if (vm86->vm86_eflags & PSL_VIP)
 335                                 break;
 336                 } else {
 337                         vm86->vm86_eflags &= ~PSL_VIF;
 338                 }
 339                 return (retcode);
 340         }
 341         return (SIGBUS);
 342 }
 343
 344 #define PGTABLE_SIZE    ((1024 + 64) * 1024 / PAGE_SIZE)
 345 #define INTMAP_SIZE     32
 346 #define IOMAP_SIZE      ctob(IOPAGES)
 347 #define TSS_SIZE \
 348         (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
 349          INTMAP_SIZE + IOMAP_SIZE + 1)
 350
 351 struct vm86_layout {
 352         pt_entry_t      vml_pgtbl[PGTABLE_SIZE];
 353         struct  pcb vml_pcb;
 354         struct  pcb_ext vml_ext;
 355         char    vml_intmap[INTMAP_SIZE];
 356         char    vml_iomap[IOMAP_SIZE];
 357         char    vml_iomap_trailer;
 358 };
 359
 360 void
 361 vm86_initialize(void)
 362 {
 363         int i;
 364         u_int *addr;
 365         struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
 366         struct pcb *pcb;
 367         struct pcb_ext *ext;
 368         struct soft_segment_descriptor ssd = {
 369                 0,                      /* segment base address (overwritten) */
 370                 0,                      /* length (overwritten) */
 371                 SDT_SYS386TSS,          /* segment type */
 372                 0,                      /* priority level */
 373                 1,                      /* descriptor present */
 374                 0, 0,
 375                 0,                      /* default 16 size */
 376                 0                       /* granularity */
 377         };
 378
 379         /*
 380          * this should be a compile time error, but cpp doesn't grok sizeof().
 381          */
 382         if (sizeof(struct vm86_layout) > ctob(3))
 383                 panic("struct vm86_layout exceeds space allocated in locore.s");
 384
 385         /*
 386          * Below is the memory layout that we use for the vm86 region.
 387          *
 388          * +--------+
 389          * |        |
 390          * |        |
 391          * | page 0 |
 392          * |        | +--------+
 393          * |        | | stack  |
 394          * +--------+ +--------+ <--------- vm86paddr
 395          * |        | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
 396          * |        | +--------+
 397          * |        | |  PCB   | size: ~240 bytes
 398          * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
 399          * |        | +--------+
 400          * |        | |int map |
 401          * |        | +--------+
 402          * +--------+ |        |
 403          * | page 2 | |  I/O   |
 404          * +--------+ | bitmap |
 405          * | page 3 | |        |
 406          * |        | +--------+
 407          * +--------+
 408          */
 409
 410         /*
 411          * A rudimentary PCB must be installed, in order to get to the
 412          * PCB extension area.  We use the PCB area as a scratchpad for
 413          * data storage, the layout of which is shown below.
 414          *
 415          * pcb_esi      = new PTD entry 0
 416          * pcb_ebp      = pointer to frame on vm86 stack
 417          * pcb_esp      =    stack frame pointer at time of switch
 418          * pcb_ebx      = va of vm86 page table
 419          * pcb_eip      =    argument pointer to initial call
 420          * pcb_spare[0] =    saved TSS descriptor, word 0
 421          * pcb_space[1] =    saved TSS descriptor, word 1
 422          */
 423 #define new_ptd         pcb_esi
 424 #define vm86_frame      pcb_ebp
 425 #define pgtable_va      pcb_ebx
 426
 427         pcb = &vml->vml_pcb;
 428         ext = &vml->vml_ext;
 429
 430         mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF);
 431
 432         bzero(pcb, sizeof(struct pcb));
 433         pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
 434         pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
 435         pcb->pgtable_va = vm86paddr;
 436         pcb->pcb_flags = PCB_VM86CALL;
 437         pcb->pcb_ext = ext;
 438
 439         bzero(ext, sizeof(struct pcb_ext));
 440         ext->ext_tss.tss_esp0 = vm86paddr;
 441         ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
 442         ext->ext_tss.tss_ioopt =
 443                 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
 444         ext->ext_iomap = vml->vml_iomap;
 445         ext->ext_vm86.vm86_intmap = vml->vml_intmap;
 446
 447         if (cpu_feature & CPUID_VME)
 448                 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 449
 450         addr = (u_int *)ext->ext_vm86.vm86_intmap;
 451         for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
 452                 *addr++ = 0;
 453         vml->vml_iomap_trailer = 0xff;
 454
 455         ssd.ssd_base = (u_int)&ext->ext_tss;
 456         ssd.ssd_limit = TSS_SIZE - 1;
 457         ssdtosd(&ssd, &ext->ext_tssd);
 458
 459         vm86pcb = pcb;
 460
 461 #if 0
 462         /*
 463          * use whatever is leftover of the vm86 page layout as a
 464          * message buffer so we can capture early output.
 465          */
 466         msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
 467             ctob(3) - sizeof(struct vm86_layout));
 468 #endif
 469 }
 470
 471 vm_offset_t
 472 vm86_getpage(struct vm86context *vmc, int pagenum)
 473 {
 474         int i;
 475
 476         for (i = 0; i < vmc->npages; i++)
 477                 if (vmc->pmap[i].pte_num == pagenum)
 478                         return (vmc->pmap[i].kva);
 479         return (0);
 480 }
 481
 482 vm_offset_t
 483 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
 484 {
 485         int i, flags = 0;
 486
 487         for (i = 0; i < vmc->npages; i++)
 488                 if (vmc->pmap[i].pte_num == pagenum)
 489                         goto overlap;
 490
 491         if (vmc->npages == VM86_PMAPSIZE)
 492                 goto full;                      /* XXX grow map? */
 493
 494         if (kva == 0) {
 495                 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
 496                 flags = VMAP_MALLOC;
 497         }
 498
 499         i = vmc->npages++;
 500         vmc->pmap[i].flags = flags;
 501         vmc->pmap[i].kva = kva;
 502         vmc->pmap[i].pte_num = pagenum;
 503         return (kva);
 504 overlap:
 505         panic("vm86_addpage: overlap");
 506 full:
 507         panic("vm86_addpage: not enough room");
 508 }
 509
 510 /*
 511  * called from vm86_bioscall, while in vm86 address space, to finalize setup.
 512  */
 513 void
 514 vm86_prepcall(struct vm86frame *vmf)
 515 {
 516         struct vm86_kernel *vm86;
 517         uint32_t *stack;
 518         uint8_t *code;
 519
 520         code = (void *)0xa00;
 521         stack = (void *)(0x1000 - 2);   /* keep aligned */
 522         if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) {
 523                 /* interrupt call requested */
 524                 code[0] = INTn;
 525                 code[1] = vmf->vmf_trapno & 0xff;
 526                 code[2] = HLT;
 527                 vmf->vmf_ip = (uintptr_t)code;
 528                 vmf->vmf_cs = 0;
 529         } else {
 530                 code[0] = HLT;
 531                 stack--;
 532                 stack[0] = MAKE_VEC(0, (uintptr_t)code);
 533         }
 534         vmf->vmf_sp = (uintptr_t)stack;
 535         vmf->vmf_ss = 0;
 536         vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = 0;
 537         vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
 538
 539         vm86 = &curpcb->pcb_ext->ext_vm86;
 540         if (!vm86->vm86_has_vme)
 541                 vm86->vm86_eflags = vmf->vmf_eflags;  /* save VIF, VIP */
 542 }
 543
 544 /*
 545  * vm86 trap handler; determines whether routine succeeded or not.
 546  * Called while in vm86 space, returns to calling process.
 547  */
 548 void
 549 vm86_trap(struct vm86frame *vmf)
 550 {
 551         caddr_t addr;
 552
 553         /* "should not happen" */
 554         if ((vmf->vmf_eflags & PSL_VM) == 0)
 555                 panic("vm86_trap called, but not in vm86 mode");
 556
 557         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 558         if (*(u_char *)addr == HLT)
 559                 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
 560         else
 561                 vmf->vmf_trapno = vmf->vmf_trapno << 16;
 562
 563         vm86_biosret(vmf);
 564 }
 565
 566 int
 567 vm86_intcall(int intnum, struct vm86frame *vmf)
 568 {
 569         int retval;
 570
 571         if (intnum < 0 || intnum > 0xff)
 572                 return (EINVAL);
 573
 574         vmf->vmf_trapno = intnum;
 575         mtx_lock(&vm86_lock);
 576         critical_enter();
 577         retval = vm86_bioscall(vmf);
 578         critical_exit();
 579         mtx_unlock(&vm86_lock);
 580         return (retval);
 581 }
 582
 583 /*
 584  * struct vm86context contains the page table to use when making
 585  * vm86 calls.  If intnum is a valid interrupt number (0-255), then
 586  * the "interrupt trampoline" will be used, otherwise we use the
 587  * caller's cs:ip routine.
 588  */
 589 int
 590 vm86_datacall(int intnum, struct vm86frame *vmf, struct vm86context *vmc)
 591 {
 592         pt_entry_t *pte = (pt_entry_t *)vm86paddr;
 593         vm_paddr_t page;
 594         int i, entry, retval;
 595
 596         mtx_lock(&vm86_lock);
 597         for (i = 0; i < vmc->npages; i++) {
 598                 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
 599                 entry = vmc->pmap[i].pte_num;
 600                 vmc->pmap[i].old_pte = pte[entry];
 601                 pte[entry] = page | PG_V | PG_RW | PG_U;
 602                 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
 603         }
 604
 605         vmf->vmf_trapno = intnum;
 606         critical_enter();
 607         retval = vm86_bioscall(vmf);
 608         critical_exit();
 609
 610         for (i = 0; i < vmc->npages; i++) {
 611                 entry = vmc->pmap[i].pte_num;
 612                 pte[entry] = vmc->pmap[i].old_pte;
 613                 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
 614         }
 615         mtx_unlock(&vm86_lock);
 616
 617         return (retval);
 618 }
 619
 620 vm_offset_t
 621 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off)
 622 {
 623         int i, page;
 624         vm_offset_t addr;
 625
 626         addr = (vm_offset_t)MAKE_ADDR(sel, off);
 627         page = addr >> PAGE_SHIFT;
 628         for (i = 0; i < vmc->npages; i++)
 629                 if (page == vmc->pmap[i].pte_num)
 630                         return (vmc->pmap[i].kva + (addr & PAGE_MASK));
 631         return (0);
 632 }
 633
 634 int
 635 vm86_getptr(struct vm86context *vmc, vm_offset_t kva, u_short *sel,
 636      u_short *off)
 637 {
 638         int i;
 639
 640         for (i = 0; i < vmc->npages; i++)
 641                 if (kva >= vmc->pmap[i].kva &&
 642                     kva < vmc->pmap[i].kva + PAGE_SIZE) {
 643                         *off = kva - vmc->pmap[i].kva;
 644                         *sel = vmc->pmap[i].pte_num << 8;
 645                         return (1);
 646                 }
 647         return (0);
 648 }
 649
 650 int
 651 vm86_sysarch(struct thread *td, char *args)
 652 {
 653         int error = 0;
 654         struct i386_vm86_args ua;
 655         struct vm86_kernel *vm86;
 656
 657         if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
 658                 return (error);
 659
 660         if (td->td_pcb->pcb_ext == 0)
 661                 if ((error = i386_extend_pcb(td)) != 0)
 662                         return (error);
 663         vm86 = &td->td_pcb->pcb_ext->ext_vm86;
 664
 665         switch (ua.sub_op) {
 666         case VM86_INIT: {
 667                 struct vm86_init_args sa;
 668
 669                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
 670                         return (error);
 671                 if (cpu_feature & CPUID_VME)
 672                         vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 673                 else
 674                         vm86->vm86_has_vme = 0;
 675                 vm86->vm86_inited = 1;
 676                 vm86->vm86_debug = sa.debug;
 677                 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
 678                 }
 679                 break;
 680
 681 #if 0
 682         case VM86_SET_VME: {
 683                 struct vm86_vme_args sa;
 684
 685                 if ((cpu_feature & CPUID_VME) == 0)
 686                         return (ENODEV);
 687
 688                 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
 689                         return (error);
 690                 if (sa.state)
 691                         load_cr4(rcr4() | CR4_VME);
 692                 else
 693                         load_cr4(rcr4() & ~CR4_VME);
 694                 }
 695                 break;
 696 #endif
 697
 698         case VM86_GET_VME: {
 699                 struct vm86_vme_args sa;
 700
 701                 sa.state = (rcr4() & CR4_VME ? 1 : 0);
 702                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 703                 }
 704                 break;
 705
 706         case VM86_INTCALL: {
 707                 struct vm86_intcall_args sa;
 708
 709                 if ((error = priv_check(td, PRIV_VM86_INTCALL)))
 710                         return (error);
 711                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
 712                         return (error);
 713                 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
 714                         return (error);
 715                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 716                 }
 717                 break;
 718
 719         default:
 720                 error = EINVAL;
 721         }
 722         return (error);
 723 }