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  * modification, are permitted provided that the following conditions
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  *
  27  * $FreeBSD: src/sys/i386/i386/vm86.c,v 1.31.2.2 2001/10/05 06:18:55 peter Exp $
  28  * $DragonFly: src/sys/i386/i386/Attic/vm86.c,v 1.11 2004/08/07 03:42:37 dillon Exp $
  29  */
  30
  31 #include <sys/param.h>
  32 #include <sys/systm.h>
  33 #include <sys/proc.h>
  34 #include <sys/lock.h>
  35 #include <sys/malloc.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 <sys/user.h>
  43 #include <sys/thread2.h>
  44
  45 #include <machine/md_var.h>
  46 #include <machine/pcb_ext.h>    /* pcb.h included via sys/user.h */
  47 #include <machine/psl.h>
  48 #include <machine/specialreg.h>
  49 #include <machine/sysarch.h>
  50 #include <machine/clock.h>
  51
  52 extern int i386_extend_pcb      (struct proc *);
  53 extern int vm86pa;
  54 extern struct pcb *vm86pcb;
  55
  56 extern int vm86_bioscall(struct vm86frame *);
  57 extern void vm86_biosret(struct vm86frame *);
  58
  59 void vm86_prepcall(struct vm86frame);
  60
  61 struct system_map {
  62         int             type;
  63         vm_offset_t     start;
  64         vm_offset_t     end;
  65 };
  66
  67 #define HLT     0xf4
  68 #define CLI     0xfa
  69 #define STI     0xfb
  70 #define PUSHF   0x9c
  71 #define POPF    0x9d
  72 #define INTn    0xcd
  73 #define IRET    0xcf
  74 #define CALLm   0xff
  75 #define OPERAND_SIZE_PREFIX     0x66
  76 #define ADDRESS_SIZE_PREFIX     0x67
  77 #define PUSH_MASK       ~(PSL_VM | PSL_RF | PSL_I)
  78 #define POP_MASK        ~(PSL_VIP | PSL_VIF | PSL_VM | PSL_RF | PSL_IOPL)
  79
  80 static __inline caddr_t
  81 MAKE_ADDR(u_short sel, u_short off)
  82 {
  83         return ((caddr_t)((sel << 4) + off));
  84 }
  85
  86 static __inline void
  87 GET_VEC(u_int vec, u_short *sel, u_short *off)
  88 {
  89         *sel = vec >> 16;
  90         *off = vec & 0xffff;
  91 }
  92
  93 static __inline u_int
  94 MAKE_VEC(u_short sel, u_short off)
  95 {
  96         return ((sel << 16) | off);
  97 }
  98
  99 static __inline void
 100 PUSH(u_short x, struct vm86frame *vmf)
 101 {
 102         vmf->vmf_sp -= 2;
 103         susword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 104 }
 105
 106 static __inline void
 107 PUSHL(u_int x, struct vm86frame *vmf)
 108 {
 109         vmf->vmf_sp -= 4;
 110         suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 111 }
 112
 113 static __inline u_short
 114 POP(struct vm86frame *vmf)
 115 {
 116         u_short x = fusword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 117
 118         vmf->vmf_sp += 2;
 119         return (x);
 120 }
 121
 122 static __inline u_int
 123 POPL(struct vm86frame *vmf)
 124 {
 125         u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 126
 127         vmf->vmf_sp += 4;
 128         return (x);
 129 }
 130
 131 int
 132 vm86_emulate(vmf)
 133         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 (curthread->td_pcb->pcb_ext == 0)
 148                 return (SIGBUS);
 149         vm86 = &curthread->td_pcb->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 (0);
 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 (0);
 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_TF, 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_TF, 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         bzero(pcb, sizeof(struct pcb));
 431         pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
 432         pcb->vm86_frame = (pt_entry_t)vm86paddr - sizeof(struct vm86frame);
 433         pcb->pgtable_va = (vm_offset_t)vm86paddr;
 434         pcb->pcb_ext = ext;
 435
 436         bzero(ext, sizeof(struct pcb_ext));
 437         ext->ext_tss.tss_esp0 = (vm_offset_t)vm86paddr;
 438         ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
 439         ext->ext_tss.tss_ioopt =
 440                 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
 441         ext->ext_iomap = vml->vml_iomap;
 442         ext->ext_vm86.vm86_intmap = vml->vml_intmap;
 443
 444         if (cpu_feature & CPUID_VME)
 445                 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 446
 447         addr = (u_int *)ext->ext_vm86.vm86_intmap;
 448         for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
 449                 *addr++ = 0;
 450         vml->vml_iomap_trailer = 0xff;
 451
 452         ssd.ssd_base = (u_int)&ext->ext_tss;
 453         ssd.ssd_limit = TSS_SIZE - 1;
 454         ssdtosd(&ssd, &ext->ext_tssd);
 455
 456         vm86pcb = pcb;
 457
 458 #if 0
 459         /*
 460          * use whatever is leftover of the vm86 page layout as a
 461          * message buffer so we can capture early output.
 462          */
 463         msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
 464             ctob(3) - sizeof(struct vm86_layout));
 465 #endif
 466 }
 467
 468 vm_offset_t
 469 vm86_getpage(struct vm86context *vmc, int pagenum)
 470 {
 471         int i;
 472
 473         for (i = 0; i < vmc->npages; i++)
 474                 if (vmc->pmap[i].pte_num == pagenum)
 475                         return (vmc->pmap[i].kva);
 476         return (0);
 477 }
 478
 479 vm_offset_t
 480 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
 481 {
 482         int i, flags = 0;
 483
 484         for (i = 0; i < vmc->npages; i++)
 485                 if (vmc->pmap[i].pte_num == pagenum)
 486                         goto bad;
 487
 488         if (vmc->npages == VM86_PMAPSIZE)
 489                 goto bad;                       /* XXX grow map? */
 490
 491         if (kva == 0) {
 492                 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
 493                 flags = VMAP_MALLOC;
 494         }
 495
 496         i = vmc->npages++;
 497         vmc->pmap[i].flags = flags;
 498         vmc->pmap[i].kva = kva;
 499         vmc->pmap[i].pte_num = pagenum;
 500         return (kva);
 501 bad:
 502         panic("vm86_addpage: not enough room, or overlap");
 503 }
 504
 505 static void
 506 vm86_initflags(struct vm86frame *vmf)
 507 {
 508         int eflags = vmf->vmf_eflags;
 509         struct vm86_kernel *vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
 510
 511         if (vm86->vm86_has_vme) {
 512                 eflags = (vmf->vmf_eflags & ~VME_USERCHANGE) |
 513                     (eflags & VME_USERCHANGE) | PSL_VM;
 514         } else {
 515                 vm86->vm86_eflags = eflags;     /* save VIF, VIP */
 516                 eflags = (vmf->vmf_eflags & ~VM_USERCHANGE) |
 517                     (eflags & VM_USERCHANGE) | PSL_VM;
 518         }
 519         vmf->vmf_eflags = eflags | PSL_VM;
 520 }
 521
 522 /*
 523  * called from vm86_bioscall, while in vm86 address space, to finalize setup.
 524  */
 525 void
 526 vm86_prepcall(struct vm86frame vmf)
 527 {
 528         uintptr_t addr[] = { 0xA00, 0x1000 };   /* code, stack */
 529         u_char intcall[] = {
 530                 CLI, INTn, 0x00, STI, HLT
 531         };
 532
 533         if ((vmf.vmf_trapno & PAGE_MASK) <= 0xff) {
 534                 /* interrupt call requested */
 535                 intcall[2] = (u_char)(vmf.vmf_trapno & 0xff);
 536                 memcpy((void *)addr[0], (void *)intcall, sizeof(intcall));
 537                 vmf.vmf_ip = addr[0];
 538                 vmf.vmf_cs = 0;
 539         }
 540         vmf.vmf_sp = addr[1] - 2;              /* keep aligned */
 541         vmf.kernel_fs = vmf.kernel_es = vmf.kernel_ds = 0;
 542         vmf.vmf_ss = 0;
 543         vmf.vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
 544         vm86_initflags(&vmf);
 545 }
 546
 547 /*
 548  * vm86 trap handler; determines whether routine succeeded or not.
 549  * Called while in vm86 space, returns to calling process.
 550  *
 551  * A MP lock ref is held on entry from trap() and must be released prior
 552  * to returning to the VM86 call.
 553  */
 554 void
 555 vm86_trap(struct vm86frame *vmf)
 556 {
 557         caddr_t addr;
 558
 559         /* "should not happen" */
 560         if ((vmf->vmf_eflags & PSL_VM) == 0)
 561                 panic("vm86_trap called, but not in vm86 mode");
 562
 563         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 564         if (*(u_char *)addr == HLT)
 565                 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
 566         else
 567                 vmf->vmf_trapno = vmf->vmf_trapno << 16;
 568
 569         rel_mplock();
 570         vm86_biosret(vmf);
 571 }
 572
 573 int
 574 vm86_intcall(int intnum, struct vm86frame *vmf)
 575 {
 576         int error;
 577
 578         if (intnum < 0 || intnum > 0xff)
 579                 return (EINVAL);
 580
 581         crit_enter();
 582         ASSERT_MP_LOCK_HELD();
 583
 584         vmf->vmf_trapno = intnum;
 585         error = vm86_bioscall(vmf);
 586 #if 0
 587         /*
 588          * removed.  This causes more problems then it solves, we will
 589          * have to find another way to detect inappropriate 8254 writes
 590          * from the bios
 591          */
 592         timer_restore();
 593 #endif
 594         crit_exit();
 595         return(error);
 596 }
 597
 598 /*
 599  * struct vm86context contains the page table to use when making
 600  * vm86 calls.  If intnum is a valid interrupt number (0-255), then
 601  * the "interrupt trampoline" will be used, otherwise we use the
 602  * caller's cs:ip routine.
 603  */
 604 int
 605 vm86_datacall(intnum, vmf, vmc)
 606         int intnum;
 607         struct vm86frame *vmf;
 608         struct vm86context *vmc;
 609 {
 610         pt_entry_t *pte = vm86paddr;
 611         u_int page;
 612         int i, entry, retval;
 613
 614         crit_enter();
 615         ASSERT_MP_LOCK_HELD();
 616
 617         for (i = 0; i < vmc->npages; i++) {
 618                 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
 619                 entry = vmc->pmap[i].pte_num;
 620                 vmc->pmap[i].old_pte = pte[entry];
 621                 pte[entry] = page | PG_V | PG_RW | PG_U;
 622         }
 623
 624         vmf->vmf_trapno = intnum;
 625         retval = vm86_bioscall(vmf);
 626
 627         for (i = 0; i < vmc->npages; i++) {
 628                 entry = vmc->pmap[i].pte_num;
 629                 pte[entry] = vmc->pmap[i].old_pte;
 630         }
 631         crit_exit();
 632         return (retval);
 633 }
 634
 635 vm_offset_t
 636 vm86_getaddr(vmc, sel, off)
 637         struct vm86context *vmc;
 638         u_short sel;
 639         u_short off;
 640 {
 641         int i, page;
 642         vm_offset_t addr;
 643
 644         addr = (vm_offset_t)MAKE_ADDR(sel, off);
 645         page = addr >> PAGE_SHIFT;
 646         for (i = 0; i < vmc->npages; i++)
 647                 if (page == vmc->pmap[i].pte_num)
 648                         return (vmc->pmap[i].kva + (addr & PAGE_MASK));
 649         return (0);
 650 }
 651
 652 int
 653 vm86_getptr(vmc, kva, sel, off)
 654         struct vm86context *vmc;
 655         vm_offset_t kva;
 656         u_short *sel;
 657         u_short *off;
 658 {
 659         int i;
 660
 661         for (i = 0; i < vmc->npages; i++)
 662                 if (kva >= vmc->pmap[i].kva &&
 663                     kva < vmc->pmap[i].kva + PAGE_SIZE) {
 664                         *off = kva - vmc->pmap[i].kva;
 665                         *sel = vmc->pmap[i].pte_num << 8;
 666                         return (1);
 667                 }
 668         return (0);
 669         panic("vm86_getptr: address not found");
 670 }
 671
 672 int
 673 vm86_sysarch(struct proc *p, char *args)
 674 {
 675         int error = 0;
 676         struct i386_vm86_args ua;
 677         struct vm86_kernel *vm86;
 678
 679         if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
 680                 return (error);
 681
 682         if (p->p_thread->td_pcb->pcb_ext == 0)
 683                 if ((error = i386_extend_pcb(p)) != 0)
 684                         return (error);
 685         vm86 = &p->p_thread->td_pcb->pcb_ext->ext_vm86;
 686
 687         switch (ua.sub_op) {
 688         case VM86_INIT: {
 689                 struct vm86_init_args sa;
 690
 691                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
 692                         return (error);
 693                 if (cpu_feature & CPUID_VME)
 694                         vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 695                 else
 696                         vm86->vm86_has_vme = 0;
 697                 vm86->vm86_inited = 1;
 698                 vm86->vm86_debug = sa.debug;
 699                 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
 700                 }
 701                 break;
 702
 703 #if 0
 704         case VM86_SET_VME: {
 705                 struct vm86_vme_args sa;
 706
 707                 if ((cpu_feature & CPUID_VME) == 0)
 708                         return (ENODEV);
 709
 710                 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
 711                         return (error);
 712                 if (sa.state)
 713                         load_cr4(rcr4() | CR4_VME);
 714                 else
 715                         load_cr4(rcr4() & ~CR4_VME);
 716                 }
 717                 break;
 718 #endif
 719
 720         case VM86_GET_VME: {
 721                 struct vm86_vme_args sa;
 722
 723                 sa.state = (rcr4() & CR4_VME ? 1 : 0);
 724                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 725                 }
 726                 break;
 727
 728         case VM86_INTCALL: {
 729                 struct vm86_intcall_args sa;
 730
 731                 if ((error = suser_cred(p->p_ucred, 0)))
 732                         return (error);
 733                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
 734                         return (error);
 735                 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
 736                         return (error);
 737                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 738                 }
 739                 break;
 740
 741         default:
 742                 error = EINVAL;
 743         }
 744         return (error);
 745 }