sys/platform/pc32/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  * $FreeBSD: src/sys/i386/i386/vm86.c,v 1.31.2.2 2001/10/05 06:18:55 peter Exp $
  27  * $DragonFly: src/sys/platform/pc32/i386/vm86.c,v 1.7 2003/07/08 06:27:26 dillon Exp $
  28  */
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/proc.h>
  33 #include <sys/lock.h>
  34 #include <sys/malloc.h>
  35
  36 #include <vm/vm.h>
  37 #include <vm/pmap.h>
  38 #include <vm/vm_map.h>
  39 #include <vm/vm_page.h>
  40
  41 #include <sys/user.h>
  42 #include <sys/thread2.h>
  43
  44 #include <machine/md_var.h>
  45 #include <machine/pcb_ext.h>    /* pcb.h included via sys/user.h */
  46 #include <machine/psl.h>
  47 #include <machine/specialreg.h>
  48 #include <machine/sysarch.h>
  49
  50 extern int i386_extend_pcb      __P((struct proc *));
  51 extern int vm86pa;
  52 extern struct pcb *vm86pcb;
  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 __inline caddr_t
  79 MAKE_ADDR(u_short sel, u_short off)
  80 {
  81         return ((caddr_t)((sel << 4) + off));
  82 }
  83
  84 static __inline void
  85 GET_VEC(u_int vec, u_short *sel, u_short *off)
  86 {
  87         *sel = vec >> 16;
  88         *off = vec & 0xffff;
  89 }
  90
  91 static __inline u_int
  92 MAKE_VEC(u_short sel, u_short off)
  93 {
  94         return ((sel << 16) | off);
  95 }
  96
  97 static __inline void
  98 PUSH(u_short x, struct vm86frame *vmf)
  99 {
 100         vmf->vmf_sp -= 2;
 101         susword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 102 }
 103
 104 static __inline void
 105 PUSHL(u_int x, struct vm86frame *vmf)
 106 {
 107         vmf->vmf_sp -= 4;
 108         suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 109 }
 110
 111 static __inline u_short
 112 POP(struct vm86frame *vmf)
 113 {
 114         u_short x = fusword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 115
 116         vmf->vmf_sp += 2;
 117         return (x);
 118 }
 119
 120 static __inline u_int
 121 POPL(struct vm86frame *vmf)
 122 {
 123         u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 124
 125         vmf->vmf_sp += 4;
 126         return (x);
 127 }
 128
 129 int
 130 vm86_emulate(vmf)
 131         struct vm86frame *vmf;
 132 {
 133         struct vm86_kernel *vm86;
 134         caddr_t addr;
 135         u_char i_byte;
 136         u_int temp_flags;
 137         int inc_ip = 1;
 138         int retcode = 0;
 139
 140         /*
 141          * pcb_ext contains the address of the extension area, or zero if
 142          * the extension is not present.  (This check should not be needed,
 143          * as we can't enter vm86 mode until we set up an extension area)
 144          */
 145         if (curthread->td_pcb->pcb_ext == 0)
 146                 return (SIGBUS);
 147         vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
 148
 149         if (vmf->vmf_eflags & PSL_T)
 150                 retcode = SIGTRAP;
 151
 152         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 153         i_byte = fubyte(addr);
 154         if (i_byte == ADDRESS_SIZE_PREFIX) {
 155                 i_byte = fubyte(++addr);
 156                 inc_ip++;
 157         }
 158
 159         if (vm86->vm86_has_vme) {
 160                 switch (i_byte) {
 161                 case OPERAND_SIZE_PREFIX:
 162                         i_byte = fubyte(++addr);
 163                         inc_ip++;
 164                         switch (i_byte) {
 165                         case PUSHF:
 166                                 if (vmf->vmf_eflags & PSL_VIF)
 167                                         PUSHL((vmf->vmf_eflags & PUSH_MASK)
 168                                             | PSL_IOPL | PSL_I, vmf);
 169                                 else
 170                                         PUSHL((vmf->vmf_eflags & PUSH_MASK)
 171                                             | PSL_IOPL, vmf);
 172                                 vmf->vmf_ip += inc_ip;
 173                                 return (0);
 174
 175                         case POPF:
 176                                 temp_flags = POPL(vmf) & POP_MASK;
 177                                 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
 178                                     | temp_flags | PSL_VM | PSL_I;
 179                                 vmf->vmf_ip += inc_ip;
 180                                 if (temp_flags & PSL_I) {
 181                                         vmf->vmf_eflags |= PSL_VIF;
 182                                         if (vmf->vmf_eflags & PSL_VIP)
 183                                                 break;
 184                                 } else {
 185                                         vmf->vmf_eflags &= ~PSL_VIF;
 186                                 }
 187                                 return (0);
 188                         }
 189                         break;
 190
 191                 /* VME faults here if VIP is set, but does not set VIF. */
 192                 case STI:
 193                         vmf->vmf_eflags |= PSL_VIF;
 194                         vmf->vmf_ip += inc_ip;
 195                         if ((vmf->vmf_eflags & PSL_VIP) == 0) {
 196                                 uprintf("fatal sti\n");
 197                                 return (SIGKILL);
 198                         }
 199                         break;
 200
 201                 /* VME if no redirection support */
 202                 case INTn:
 203                         break;
 204
 205                 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
 206                 case POPF:
 207                         temp_flags = POP(vmf) & POP_MASK;
 208                         vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 209                             | temp_flags | PSL_VM | PSL_I;
 210                         vmf->vmf_ip += inc_ip;
 211                         if (temp_flags & PSL_I) {
 212                                 vmf->vmf_eflags |= PSL_VIF;
 213                                 if (vmf->vmf_eflags & PSL_VIP)
 214                                         break;
 215                         } else {
 216                                 vmf->vmf_eflags &= ~PSL_VIF;
 217                         }
 218                         return (retcode);
 219
 220                 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
 221                 case IRET:
 222                         vmf->vmf_ip = POP(vmf);
 223                         vmf->vmf_cs = POP(vmf);
 224                         temp_flags = POP(vmf) & POP_MASK;
 225                         vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 226                             | temp_flags | PSL_VM | PSL_I;
 227                         if (temp_flags & PSL_I) {
 228                                 vmf->vmf_eflags |= PSL_VIF;
 229                                 if (vmf->vmf_eflags & PSL_VIP)
 230                                         break;
 231                         } else {
 232                                 vmf->vmf_eflags &= ~PSL_VIF;
 233                         }
 234                         return (retcode);
 235
 236                 }
 237                 return (SIGBUS);
 238         }
 239
 240         switch (i_byte) {
 241         case OPERAND_SIZE_PREFIX:
 242                 i_byte = fubyte(++addr);
 243                 inc_ip++;
 244                 switch (i_byte) {
 245                 case PUSHF:
 246                         if (vm86->vm86_eflags & PSL_VIF)
 247                                 PUSHL((vmf->vmf_flags & PUSH_MASK)
 248                                     | PSL_IOPL | PSL_I, vmf);
 249                         else
 250                                 PUSHL((vmf->vmf_flags & PUSH_MASK)
 251                                     | PSL_IOPL, vmf);
 252                         vmf->vmf_ip += inc_ip;
 253                         return (retcode);
 254
 255                 case POPF:
 256                         temp_flags = POPL(vmf) & POP_MASK;
 257                         vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
 258                             | temp_flags | PSL_VM | PSL_I;
 259                         vmf->vmf_ip += inc_ip;
 260                         if (temp_flags & PSL_I) {
 261                                 vm86->vm86_eflags |= PSL_VIF;
 262                                 if (vm86->vm86_eflags & PSL_VIP)
 263                                         break;
 264                         } else {
 265                                 vm86->vm86_eflags &= ~PSL_VIF;
 266                         }
 267                         return (retcode);
 268                 }
 269                 return (SIGBUS);
 270
 271         case CLI:
 272                 vm86->vm86_eflags &= ~PSL_VIF;
 273                 vmf->vmf_ip += inc_ip;
 274                 return (retcode);
 275
 276         case STI:
 277                 /* if there is a pending interrupt, go to the emulator */
 278                 vm86->vm86_eflags |= PSL_VIF;
 279                 vmf->vmf_ip += inc_ip;
 280                 if (vm86->vm86_eflags & PSL_VIP)
 281                         break;
 282                 return (retcode);
 283
 284         case PUSHF:
 285                 if (vm86->vm86_eflags & PSL_VIF)
 286                         PUSH((vmf->vmf_flags & PUSH_MASK)
 287                             | PSL_IOPL | PSL_I, vmf);
 288                 else
 289                         PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
 290                 vmf->vmf_ip += inc_ip;
 291                 return (retcode);
 292
 293         case INTn:
 294                 i_byte = fubyte(addr + 1);
 295                 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
 296                         break;
 297                 if (vm86->vm86_eflags & PSL_VIF)
 298                         PUSH((vmf->vmf_flags & PUSH_MASK)
 299                             | PSL_IOPL | PSL_I, vmf);
 300                 else
 301                         PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
 302                 PUSH(vmf->vmf_cs, vmf);
 303                 PUSH(vmf->vmf_ip + inc_ip + 1, vmf);    /* increment IP */
 304                 GET_VEC(fuword((caddr_t)(i_byte * 4)),
 305                      &vmf->vmf_cs, &vmf->vmf_ip);
 306                 vmf->vmf_flags &= ~PSL_T;
 307                 vm86->vm86_eflags &= ~PSL_VIF;
 308                 return (retcode);
 309
 310         case IRET:
 311                 vmf->vmf_ip = POP(vmf);
 312                 vmf->vmf_cs = POP(vmf);
 313                 temp_flags = POP(vmf) & POP_MASK;
 314                 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 315                     | temp_flags | PSL_VM | PSL_I;
 316                 if (temp_flags & PSL_I) {
 317                         vm86->vm86_eflags |= PSL_VIF;
 318                         if (vm86->vm86_eflags & PSL_VIP)
 319                                 break;
 320                 } else {
 321                         vm86->vm86_eflags &= ~PSL_VIF;
 322                 }
 323                 return (retcode);
 324
 325         case POPF:
 326                 temp_flags = POP(vmf) & POP_MASK;
 327                 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 328                     | temp_flags | PSL_VM | PSL_I;
 329                 vmf->vmf_ip += inc_ip;
 330                 if (temp_flags & PSL_I) {
 331                         vm86->vm86_eflags |= PSL_VIF;
 332                         if (vm86->vm86_eflags & PSL_VIP)
 333                                 break;
 334                 } else {
 335                         vm86->vm86_eflags &= ~PSL_VIF;
 336                 }
 337                 return (retcode);
 338         }
 339         return (SIGBUS);
 340 }
 341
 342 #define PGTABLE_SIZE    ((1024 + 64) * 1024 / PAGE_SIZE)
 343 #define INTMAP_SIZE     32
 344 #define IOMAP_SIZE      ctob(IOPAGES)
 345 #define TSS_SIZE \
 346         (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
 347          INTMAP_SIZE + IOMAP_SIZE + 1)
 348
 349 struct vm86_layout {
 350         pt_entry_t      vml_pgtbl[PGTABLE_SIZE];
 351         struct  pcb vml_pcb;
 352         struct  pcb_ext vml_ext;
 353         char    vml_intmap[INTMAP_SIZE];
 354         char    vml_iomap[IOMAP_SIZE];
 355         char    vml_iomap_trailer;
 356 };
 357
 358 void
 359 vm86_initialize(void)
 360 {
 361         int i;
 362         u_int *addr;
 363         struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
 364         struct pcb *pcb;
 365         struct pcb_ext *ext;
 366         struct soft_segment_descriptor ssd = {
 367                 0,                      /* segment base address (overwritten) */
 368                 0,                      /* length (overwritten) */
 369                 SDT_SYS386TSS,          /* segment type */
 370                 0,                      /* priority level */
 371                 1,                      /* descriptor present */
 372                 0, 0,
 373                 0,                      /* default 16 size */
 374                 0                       /* granularity */
 375         };
 376
 377         /*
 378          * this should be a compile time error, but cpp doesn't grok sizeof().
 379          */
 380         if (sizeof(struct vm86_layout) > ctob(3))
 381                 panic("struct vm86_layout exceeds space allocated in locore.s");
 382
 383         /*
 384          * Below is the memory layout that we use for the vm86 region.
 385          *
 386          * +--------+
 387          * |        |
 388          * |        |
 389          * | page 0 |
 390          * |        | +--------+
 391          * |        | | stack  |
 392          * +--------+ +--------+ <--------- vm86paddr
 393          * |        | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
 394          * |        | +--------+
 395          * |        | |  PCB   | size: ~240 bytes
 396          * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
 397          * |        | +--------+
 398          * |        | |int map |
 399          * |        | +--------+
 400          * +--------+ |        |
 401          * | page 2 | |  I/O   |
 402          * +--------+ | bitmap |
 403          * | page 3 | |        |
 404          * |        | +--------+
 405          * +--------+
 406          */
 407
 408         /*
 409          * A rudimentary PCB must be installed, in order to get to the
 410          * PCB extension area.  We use the PCB area as a scratchpad for
 411          * data storage, the layout of which is shown below.
 412          *
 413          * pcb_esi      = new PTD entry 0
 414          * pcb_ebp      = pointer to frame on vm86 stack
 415          * pcb_esp      =    stack frame pointer at time of switch
 416          * pcb_ebx      = va of vm86 page table
 417          * pcb_eip      =    argument pointer to initial call
 418          * pcb_spare[0] =    saved TSS descriptor, word 0
 419          * pcb_space[1] =    saved TSS descriptor, word 1
 420          */
 421 #define new_ptd         pcb_esi
 422 #define vm86_frame      pcb_ebp
 423 #define pgtable_va      pcb_ebx
 424
 425         pcb = &vml->vml_pcb;
 426         ext = &vml->vml_ext;
 427
 428         bzero(pcb, sizeof(struct pcb));
 429         pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
 430         pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
 431         pcb->pgtable_va = vm86paddr;
 432         pcb->pcb_ext = ext;
 433
 434         bzero(ext, sizeof(struct pcb_ext));
 435         ext->ext_tss.tss_esp0 = vm86paddr;
 436         ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
 437         ext->ext_tss.tss_ioopt =
 438                 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
 439         ext->ext_iomap = vml->vml_iomap;
 440         ext->ext_vm86.vm86_intmap = vml->vml_intmap;
 441
 442         if (cpu_feature & CPUID_VME)
 443                 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 444
 445         addr = (u_int *)ext->ext_vm86.vm86_intmap;
 446         for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
 447                 *addr++ = 0;
 448         vml->vml_iomap_trailer = 0xff;
 449
 450         ssd.ssd_base = (u_int)&ext->ext_tss;
 451         ssd.ssd_limit = TSS_SIZE - 1;
 452         ssdtosd(&ssd, &ext->ext_tssd);
 453
 454         vm86pcb = pcb;
 455
 456 #if 0
 457         /*
 458          * use whatever is leftover of the vm86 page layout as a
 459          * message buffer so we can capture early output.
 460          */
 461         msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
 462             ctob(3) - sizeof(struct vm86_layout));
 463 #endif
 464 }
 465
 466 vm_offset_t
 467 vm86_getpage(struct vm86context *vmc, int pagenum)
 468 {
 469         int i;
 470
 471         for (i = 0; i < vmc->npages; i++)
 472                 if (vmc->pmap[i].pte_num == pagenum)
 473                         return (vmc->pmap[i].kva);
 474         return (0);
 475 }
 476
 477 vm_offset_t
 478 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
 479 {
 480         int i, flags = 0;
 481
 482         for (i = 0; i < vmc->npages; i++)
 483                 if (vmc->pmap[i].pte_num == pagenum)
 484                         goto bad;
 485
 486         if (vmc->npages == VM86_PMAPSIZE)
 487                 goto bad;                       /* XXX grow map? */
 488
 489         if (kva == 0) {
 490                 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
 491                 flags = VMAP_MALLOC;
 492         }
 493
 494         i = vmc->npages++;
 495         vmc->pmap[i].flags = flags;
 496         vmc->pmap[i].kva = kva;
 497         vmc->pmap[i].pte_num = pagenum;
 498         return (kva);
 499 bad:
 500         panic("vm86_addpage: not enough room, or overlap");
 501 }
 502
 503 static void
 504 vm86_initflags(struct vm86frame *vmf)
 505 {
 506         int eflags = vmf->vmf_eflags;
 507         struct vm86_kernel *vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
 508
 509         if (vm86->vm86_has_vme) {
 510                 eflags = (vmf->vmf_eflags & ~VME_USERCHANGE) |
 511                     (eflags & VME_USERCHANGE) | PSL_VM;
 512         } else {
 513                 vm86->vm86_eflags = eflags;     /* save VIF, VIP */
 514                 eflags = (vmf->vmf_eflags & ~VM_USERCHANGE) |
 515                     (eflags & VM_USERCHANGE) | PSL_VM;
 516         }
 517         vmf->vmf_eflags = eflags | PSL_VM;
 518 }
 519
 520 /*
 521  * called from vm86_bioscall, while in vm86 address space, to finalize setup.
 522  */
 523 void
 524 vm86_prepcall(struct vm86frame vmf)
 525 {
 526         uintptr_t addr[] = { 0xA00, 0x1000 };   /* code, stack */
 527         u_char intcall[] = {
 528                 CLI, INTn, 0x00, STI, HLT
 529         };
 530
 531         if ((vmf.vmf_trapno & PAGE_MASK) <= 0xff) {
 532                 /* interrupt call requested */
 533                 intcall[2] = (u_char)(vmf.vmf_trapno & 0xff);
 534                 memcpy((void *)addr[0], (void *)intcall, sizeof(intcall));
 535                 vmf.vmf_ip = addr[0];
 536                 vmf.vmf_cs = 0;
 537         }
 538         vmf.vmf_sp = addr[1] - 2;              /* keep aligned */
 539         vmf.kernel_fs = vmf.kernel_es = vmf.kernel_ds = 0;
 540         vmf.vmf_ss = 0;
 541         vmf.vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
 542         vm86_initflags(&vmf);
 543 }
 544
 545 /*
 546  * vm86 trap handler; determines whether routine succeeded or not.
 547  * Called while in vm86 space, returns to calling process.
 548  *
 549  * A MP lock ref is held on entry from trap() and must be released prior
 550  * to returning to the VM86 call.
 551  */
 552 void
 553 vm86_trap(struct vm86frame *vmf)
 554 {
 555         caddr_t addr;
 556
 557         /* "should not happen" */
 558         if ((vmf->vmf_eflags & PSL_VM) == 0)
 559                 panic("vm86_trap called, but not in vm86 mode");
 560
 561         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 562         if (*(u_char *)addr == HLT)
 563                 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
 564         else
 565                 vmf->vmf_trapno = vmf->vmf_trapno << 16;
 566
 567         rel_mplock();
 568         vm86_biosret(vmf);
 569 }
 570
 571 int
 572 vm86_intcall(int intnum, struct vm86frame *vmf)
 573 {
 574         int error;
 575
 576         if (intnum < 0 || intnum > 0xff)
 577                 return (EINVAL);
 578
 579         crit_enter();
 580         ASSERT_MP_LOCK_HELD();
 581
 582         vmf->vmf_trapno = intnum;
 583         error = vm86_bioscall(vmf);
 584         crit_exit();
 585         return(error);
 586 }
 587
 588 /*
 589  * struct vm86context contains the page table to use when making
 590  * vm86 calls.  If intnum is a valid interrupt number (0-255), then
 591  * the "interrupt trampoline" will be used, otherwise we use the
 592  * caller's cs:ip routine.
 593  */
 594 int
 595 vm86_datacall(intnum, vmf, vmc)
 596         int intnum;
 597         struct vm86frame *vmf;
 598         struct vm86context *vmc;
 599 {
 600         pt_entry_t pte = (pt_entry_t)vm86paddr;
 601         u_int page;
 602         int i, entry, retval;
 603
 604         crit_enter();
 605         ASSERT_MP_LOCK_HELD();
 606
 607         for (i = 0; i < vmc->npages; i++) {
 608                 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
 609                 entry = vmc->pmap[i].pte_num;
 610                 vmc->pmap[i].old_pte = pte[entry];
 611                 pte[entry] = page | PG_V | PG_RW | PG_U;
 612         }
 613
 614         vmf->vmf_trapno = intnum;
 615         retval = vm86_bioscall(vmf);
 616
 617         for (i = 0; i < vmc->npages; i++) {
 618                 entry = vmc->pmap[i].pte_num;
 619                 pte[entry] = vmc->pmap[i].old_pte;
 620         }
 621         crit_exit();
 622         return (retval);
 623 }
 624
 625 vm_offset_t
 626 vm86_getaddr(vmc, sel, off)
 627         struct vm86context *vmc;
 628         u_short sel;
 629         u_short off;
 630 {
 631         int i, page;
 632         vm_offset_t addr;
 633
 634         addr = (vm_offset_t)MAKE_ADDR(sel, off);
 635         page = addr >> PAGE_SHIFT;
 636         for (i = 0; i < vmc->npages; i++)
 637                 if (page == vmc->pmap[i].pte_num)
 638                         return (vmc->pmap[i].kva + (addr & PAGE_MASK));
 639         return (0);
 640 }
 641
 642 int
 643 vm86_getptr(vmc, kva, sel, off)
 644         struct vm86context *vmc;
 645         vm_offset_t kva;
 646         u_short *sel;
 647         u_short *off;
 648 {
 649         int i;
 650
 651         for (i = 0; i < vmc->npages; i++)
 652                 if (kva >= vmc->pmap[i].kva &&
 653                     kva < vmc->pmap[i].kva + PAGE_SIZE) {
 654                         *off = kva - vmc->pmap[i].kva;
 655                         *sel = vmc->pmap[i].pte_num << 8;
 656                         return (1);
 657                 }
 658         return (0);
 659         panic("vm86_getptr: address not found");
 660 }
 661
 662 int
 663 vm86_sysarch(struct proc *p, char *args)
 664 {
 665         int error = 0;
 666         struct i386_vm86_args ua;
 667         struct vm86_kernel *vm86;
 668
 669         if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
 670                 return (error);
 671
 672         if (p->p_thread->td_pcb->pcb_ext == 0)
 673                 if ((error = i386_extend_pcb(p)) != 0)
 674                         return (error);
 675         vm86 = &p->p_thread->td_pcb->pcb_ext->ext_vm86;
 676
 677         switch (ua.sub_op) {
 678         case VM86_INIT: {
 679                 struct vm86_init_args sa;
 680
 681                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
 682                         return (error);
 683                 if (cpu_feature & CPUID_VME)
 684                         vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 685                 else
 686                         vm86->vm86_has_vme = 0;
 687                 vm86->vm86_inited = 1;
 688                 vm86->vm86_debug = sa.debug;
 689                 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
 690                 }
 691                 break;
 692
 693 #if 0
 694         case VM86_SET_VME: {
 695                 struct vm86_vme_args sa;
 696
 697                 if ((cpu_feature & CPUID_VME) == 0)
 698                         return (ENODEV);
 699
 700                 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
 701                         return (error);
 702                 if (sa.state)
 703                         load_cr4(rcr4() | CR4_VME);
 704                 else
 705                         load_cr4(rcr4() & ~CR4_VME);
 706                 }
 707                 break;
 708 #endif
 709
 710         case VM86_GET_VME: {
 711                 struct vm86_vme_args sa;
 712
 713                 sa.state = (rcr4() & CR4_VME ? 1 : 0);
 714                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 715                 }
 716                 break;
 717
 718         case VM86_INTCALL: {
 719                 struct vm86_intcall_args sa;
 720
 721                 if ((error = suser_cred(p->p_ucred, 0)))
 722                         return (error);
 723                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
 724                         return (error);
 725                 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
 726                         return (error);
 727                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 728                 }
 729                 break;
 730
 731         default:
 732                 error = EINVAL;
 733         }
 734         return (error);
 735 }