sys/i386/i386/vm86.c

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