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  * 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/platform/pc32/i386/vm86.c,v 1.26 2008/08/02 01:14:43 dillon Exp $
  29  */
  30
  31 #include <sys/param.h>
  32 #include <sys/systm.h>
  33 #include <sys/kernel.h>
  34 #include <sys/proc.h>
  35 #include <sys/priv.h>
  36 #include <sys/lock.h>
  37 #include <sys/malloc.h>
  38 #include <sys/sysctl.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 <sys/user.h>
  46
  47 #include <sys/thread2.h>
  48 #include <sys/mplock2.h>
  49
  50 #include <machine/md_var.h>
  51 #include <machine/pcb_ext.h>    /* pcb.h included via sys/user.h */
  52 #include <machine/psl.h>
  53 #include <machine/specialreg.h>
  54 #include <machine/sysarch.h>
  55 #include <machine/clock.h>
  56 #include <bus/isa/isa.h>
  57 #include <bus/isa/rtc.h>
  58 #include <machine_base/isa/timerreg.h>
  59
  60 extern int i386_extend_pcb      (struct lwp *);
  61 extern int vm86pa;
  62 extern struct pcb *vm86pcb;
  63
  64 extern int vm86_bioscall(struct vm86frame *);
  65 extern void vm86_biosret(struct vm86frame *);
  66
  67 #define PGTABLE_SIZE    ((1024 + 64) * 1024 / PAGE_SIZE)
  68 #define INTMAP_SIZE     32
  69 #define IOMAP_SIZE      ctob(IOPAGES)
  70 #define TSS_SIZE \
  71         (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
  72          INTMAP_SIZE + IOMAP_SIZE + 1)
  73
  74 struct vm86_layout {
  75         pt_entry_t      vml_pgtbl[PGTABLE_SIZE];
  76         struct  pcb vml_pcb;
  77         struct  pcb_ext vml_ext;
  78         char    vml_intmap[INTMAP_SIZE];
  79         char    vml_iomap[IOMAP_SIZE];
  80         char    vml_iomap_trailer;
  81 };
  82
  83 void vm86_prepcall(struct vm86frame *);
  84
  85 struct system_map {
  86         int             type;
  87         vm_offset_t     start;
  88         vm_offset_t     end;
  89 };
  90
  91 #define HLT     0xf4
  92 #define CLI     0xfa
  93 #define STI     0xfb
  94 #define PUSHF   0x9c
  95 #define POPF    0x9d
  96 #define INTn    0xcd
  97 #define IRET    0xcf
  98 #define INB     0xe4
  99 #define INW     0xe5
 100 #define INBDX   0xec
 101 #define INWDX   0xed
 102 #define OUTB    0xe6
 103 #define OUTW    0xe7
 104 #define OUTBDX  0xee
 105 #define OUTWDX  0xef
 106 #define CALLm   0xff
 107 #define OPERAND_SIZE_PREFIX     0x66
 108 #define ADDRESS_SIZE_PREFIX     0x67
 109 #define PUSH_MASK       ~(PSL_VM | PSL_RF | PSL_I)
 110 #define POP_MASK        ~(PSL_VIP | PSL_VIF | PSL_VM | PSL_RF | PSL_IOPL)
 111
 112 static void vm86_setup_timer_fault(void);
 113 static void vm86_clear_timer_fault(void);
 114
 115 static int vm86_blew_up_timer;
 116
 117 static int timer_warn = 1;
 118 SYSCTL_INT(_debug, OID_AUTO, timer_warn, CTLFLAG_RW, &timer_warn, 0,
 119     "Warn if BIOS has played with the 8254 timer");
 120
 121 static __inline caddr_t
 122 MAKE_ADDR(u_short sel, u_short off)
 123 {
 124         return ((caddr_t)((sel << 4) + off));
 125 }
 126
 127 static __inline void
 128 GET_VEC(u_int vec, u_short *sel, u_short *off)
 129 {
 130         *sel = vec >> 16;
 131         *off = vec & 0xffff;
 132 }
 133
 134 static __inline u_int
 135 MAKE_VEC(u_short sel, u_short off)
 136 {
 137         return ((sel << 16) | off);
 138 }
 139
 140 static __inline void
 141 PUSH(u_short x, struct vm86frame *vmf)
 142 {
 143         vmf->vmf_sp -= 2;
 144         susword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 145 }
 146
 147 static __inline void
 148 PUSHL(u_int x, struct vm86frame *vmf)
 149 {
 150         vmf->vmf_sp -= 4;
 151         suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
 152 }
 153
 154 static __inline u_short
 155 POP(struct vm86frame *vmf)
 156 {
 157         u_short x = fusword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 158
 159         vmf->vmf_sp += 2;
 160         return (x);
 161 }
 162
 163 static __inline u_int
 164 POPL(struct vm86frame *vmf)
 165 {
 166         u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
 167
 168         vmf->vmf_sp += 4;
 169         return (x);
 170 }
 171
 172 /*
 173  * MPSAFE
 174  */
 175 int
 176 vm86_emulate(struct vm86frame *vmf)
 177 {
 178         struct vm86_kernel *vm86;
 179         caddr_t addr;
 180         u_char i_byte;
 181         u_int temp_flags;
 182         int inc_ip = 1;
 183         int retcode = 0;
 184
 185         /*
 186          * pcb_ext contains the address of the extension area, or zero if
 187          * the extension is not present.  (This check should not be needed,
 188          * as we can't enter vm86 mode until we set up an extension area)
 189          */
 190         if (curthread->td_pcb->pcb_ext == 0)
 191                 return (SIGBUS);
 192         vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
 193
 194         if (vmf->vmf_eflags & PSL_T)
 195                 retcode = SIGTRAP;
 196
 197         /*
 198          * Instruction emulation
 199          */
 200         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 201         i_byte = fubyte(addr);
 202         if (i_byte == ADDRESS_SIZE_PREFIX) {
 203                 i_byte = fubyte(++addr);
 204                 inc_ip++;
 205         }
 206
 207         /*
 208          * I/O emulation (TIMER only, a big hack).  Just reenable the
 209          * IO bits involved, flag it, and retry the instruction.
 210          */
 211         switch(i_byte) {
 212         case OUTB:
 213         case OUTW:
 214         case OUTBDX:
 215         case OUTWDX:
 216                 vm86_blew_up_timer = 1;
 217                 /* fall through */
 218         case INB:
 219         case INW:
 220         case INBDX:
 221         case INWDX:
 222                 vm86_clear_timer_fault();
 223                 /* retry insn */
 224                 return(0);
 225         }
 226
 227         if (vm86->vm86_has_vme) {
 228                 switch (i_byte) {
 229                 case OPERAND_SIZE_PREFIX:
 230                         i_byte = fubyte(++addr);
 231                         inc_ip++;
 232                         switch (i_byte) {
 233                         case PUSHF:
 234                                 if (vmf->vmf_eflags & PSL_VIF)
 235                                         PUSHL((vmf->vmf_eflags & PUSH_MASK)
 236                                             | PSL_IOPL | PSL_I, vmf);
 237                                 else
 238                                         PUSHL((vmf->vmf_eflags & PUSH_MASK)
 239                                             | PSL_IOPL, vmf);
 240                                 vmf->vmf_ip += inc_ip;
 241                                 return (0);
 242
 243                         case POPF:
 244                                 temp_flags = POPL(vmf) & POP_MASK;
 245                                 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
 246                                     | temp_flags | PSL_VM | PSL_I;
 247                                 vmf->vmf_ip += inc_ip;
 248                                 if (temp_flags & PSL_I) {
 249                                         vmf->vmf_eflags |= PSL_VIF;
 250                                         if (vmf->vmf_eflags & PSL_VIP)
 251                                                 break;
 252                                 } else {
 253                                         vmf->vmf_eflags &= ~PSL_VIF;
 254                                 }
 255                                 return (0);
 256                         }
 257                         break;
 258
 259                 /* VME faults here if VIP is set, but does not set VIF. */
 260                 case STI:
 261                         vmf->vmf_eflags |= PSL_VIF;
 262                         vmf->vmf_ip += inc_ip;
 263                         if ((vmf->vmf_eflags & PSL_VIP) == 0) {
 264                                 uprintf("fatal sti\n");
 265                                 return (SIGKILL);
 266                         }
 267                         break;
 268
 269                 /* VME if no redirection support */
 270                 case INTn:
 271                         break;
 272
 273                 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
 274                 case POPF:
 275                         temp_flags = POP(vmf) & POP_MASK;
 276                         vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 277                             | temp_flags | PSL_VM | PSL_I;
 278                         vmf->vmf_ip += inc_ip;
 279                         if (temp_flags & PSL_I) {
 280                                 vmf->vmf_eflags |= PSL_VIF;
 281                                 if (vmf->vmf_eflags & PSL_VIP)
 282                                         break;
 283                         } else {
 284                                 vmf->vmf_eflags &= ~PSL_VIF;
 285                         }
 286                         return (retcode);
 287
 288                 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
 289                 case IRET:
 290                         vmf->vmf_ip = POP(vmf);
 291                         vmf->vmf_cs = POP(vmf);
 292                         temp_flags = POP(vmf) & POP_MASK;
 293                         vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 294                             | temp_flags | PSL_VM | PSL_I;
 295                         if (temp_flags & PSL_I) {
 296                                 vmf->vmf_eflags |= PSL_VIF;
 297                                 if (vmf->vmf_eflags & PSL_VIP)
 298                                         break;
 299                         } else {
 300                                 vmf->vmf_eflags &= ~PSL_VIF;
 301                         }
 302                         return (retcode);
 303
 304                 }
 305                 return (SIGBUS);
 306         }
 307
 308         switch (i_byte) {
 309         case OPERAND_SIZE_PREFIX:
 310                 i_byte = fubyte(++addr);
 311                 inc_ip++;
 312                 switch (i_byte) {
 313                 case PUSHF:
 314                         if (vm86->vm86_eflags & PSL_VIF)
 315                                 PUSHL((vmf->vmf_flags & PUSH_MASK)
 316                                     | PSL_IOPL | PSL_I, vmf);
 317                         else
 318                                 PUSHL((vmf->vmf_flags & PUSH_MASK)
 319                                     | PSL_IOPL, vmf);
 320                         vmf->vmf_ip += inc_ip;
 321                         return (retcode);
 322
 323                 case POPF:
 324                         temp_flags = POPL(vmf) & POP_MASK;
 325                         vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
 326                             | temp_flags | PSL_VM | PSL_I;
 327                         vmf->vmf_ip += inc_ip;
 328                         if (temp_flags & PSL_I) {
 329                                 vm86->vm86_eflags |= PSL_VIF;
 330                                 if (vm86->vm86_eflags & PSL_VIP)
 331                                         break;
 332                         } else {
 333                                 vm86->vm86_eflags &= ~PSL_VIF;
 334                         }
 335                         return (retcode);
 336                 }
 337                 return (SIGBUS);
 338
 339         case CLI:
 340                 vm86->vm86_eflags &= ~PSL_VIF;
 341                 vmf->vmf_ip += inc_ip;
 342                 return (retcode);
 343
 344         case STI:
 345                 /* if there is a pending interrupt, go to the emulator */
 346                 vm86->vm86_eflags |= PSL_VIF;
 347                 vmf->vmf_ip += inc_ip;
 348                 if (vm86->vm86_eflags & PSL_VIP)
 349                         break;
 350                 return (retcode);
 351
 352         case PUSHF:
 353                 if (vm86->vm86_eflags & PSL_VIF)
 354                         PUSH((vmf->vmf_flags & PUSH_MASK)
 355                             | PSL_IOPL | PSL_I, vmf);
 356                 else
 357                         PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
 358                 vmf->vmf_ip += inc_ip;
 359                 return (retcode);
 360
 361         case INTn:
 362                 i_byte = fubyte(addr + 1);
 363                 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
 364                         break;
 365                 if (vm86->vm86_eflags & PSL_VIF)
 366                         PUSH((vmf->vmf_flags & PUSH_MASK)
 367                             | PSL_IOPL | PSL_I, vmf);
 368                 else
 369                         PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
 370                 PUSH(vmf->vmf_cs, vmf);
 371                 PUSH(vmf->vmf_ip + inc_ip + 1, vmf);    /* increment IP */
 372                 GET_VEC(fuword((caddr_t)(i_byte * 4)),
 373                      &vmf->vmf_cs, &vmf->vmf_ip);
 374                 vmf->vmf_flags &= ~PSL_T;
 375                 vm86->vm86_eflags &= ~PSL_VIF;
 376                 return (retcode);
 377
 378         case IRET:
 379                 vmf->vmf_ip = POP(vmf);
 380                 vmf->vmf_cs = POP(vmf);
 381                 temp_flags = POP(vmf) & POP_MASK;
 382                 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 383                     | temp_flags | PSL_VM | PSL_I;
 384                 if (temp_flags & PSL_I) {
 385                         vm86->vm86_eflags |= PSL_VIF;
 386                         if (vm86->vm86_eflags & PSL_VIP)
 387                                 break;
 388                 } else {
 389                         vm86->vm86_eflags &= ~PSL_VIF;
 390                 }
 391                 return (retcode);
 392
 393         case POPF:
 394                 temp_flags = POP(vmf) & POP_MASK;
 395                 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
 396                     | temp_flags | PSL_VM | PSL_I;
 397                 vmf->vmf_ip += inc_ip;
 398                 if (temp_flags & PSL_I) {
 399                         vm86->vm86_eflags |= PSL_VIF;
 400                         if (vm86->vm86_eflags & PSL_VIP)
 401                                 break;
 402                 } else {
 403                         vm86->vm86_eflags &= ~PSL_VIF;
 404                 }
 405                 return (retcode);
 406         }
 407         return (SIGBUS);
 408 }
 409
 410 void
 411 vm86_initialize(void)
 412 {
 413         int i;
 414         u_int *addr;
 415         struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
 416         struct pcb *pcb;
 417         struct pcb_ext *ext;
 418         struct soft_segment_descriptor ssd = {
 419                 0,                      /* segment base address (overwritten) */
 420                 0,                      /* length (overwritten) */
 421                 SDT_SYS386TSS,          /* segment type */
 422                 0,                      /* priority level */
 423                 1,                      /* descriptor present */
 424                 0, 0,
 425                 0,                      /* default 16 size */
 426                 0                       /* granularity */
 427         };
 428
 429         /*
 430          * this should be a compile time error, but cpp doesn't grok sizeof().
 431          */
 432         if (sizeof(struct vm86_layout) > ctob(3))
 433                 panic("struct vm86_layout exceeds space allocated in locore.s");
 434
 435         /*
 436          * Below is the memory layout that we use for the vm86 region.
 437          *
 438          * +--------+
 439          * |        |
 440          * |        |
 441          * | page 0 |
 442          * |        | +--------+
 443          * |        | | stack  |
 444          * +--------+ +--------+ <--------- vm86paddr
 445          * |        | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
 446          * |        | +--------+
 447          * |        | |  PCB   | size: ~240 bytes
 448          * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
 449          * |        | +--------+
 450          * |        | |int map |
 451          * |        | +--------+
 452          * +--------+ |        |
 453          * | page 2 | |  I/O   |
 454          * +--------+ | bitmap |
 455          * | page 3 | |        |
 456          * |        | +--------+
 457          * +--------+
 458          */
 459
 460         /*
 461          * A rudimentary PCB must be installed, in order to get to the
 462          * PCB extension area.  We use the PCB area as a scratchpad for
 463          * data storage, the layout of which is shown below.
 464          *
 465          * pcb_esi      = new PTD entry 0
 466          * pcb_ebp      = pointer to frame on vm86 stack
 467          * pcb_esp      =    stack frame pointer at time of switch
 468          * pcb_ebx      = va of vm86 page table
 469          * pcb_eip      =    argument pointer to initial call
 470          * pcb_spare[0] =    saved TSS descriptor, word 0
 471          * pcb_space[1] =    saved TSS descriptor, word 1
 472          */
 473 #define new_ptd         pcb_esi
 474 #define vm86_frame      pcb_ebp
 475 #define pgtable_va      pcb_ebx
 476
 477         pcb = &vml->vml_pcb;
 478         ext = &vml->vml_ext;
 479
 480         bzero(pcb, sizeof(struct pcb));
 481         pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
 482         pcb->vm86_frame = (pt_entry_t)vm86paddr - sizeof(struct vm86frame);
 483         pcb->pgtable_va = (vm_offset_t)vm86paddr;
 484         pcb->pcb_ext = ext;
 485
 486         bzero(ext, sizeof(struct pcb_ext));
 487         ext->ext_tss.tss_esp0 = (vm_offset_t)vm86paddr;
 488         ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
 489         ext->ext_tss.tss_ioopt =
 490                 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
 491         ext->ext_iomap = vml->vml_iomap;
 492         ext->ext_vm86.vm86_intmap = vml->vml_intmap;
 493
 494         if (cpu_feature & CPUID_VME)
 495                 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 496
 497         addr = (u_int *)ext->ext_vm86.vm86_intmap;
 498         for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
 499                 *addr++ = 0;
 500         vml->vml_iomap_trailer = 0xff;
 501
 502         ssd.ssd_base = (u_int)&ext->ext_tss;
 503         ssd.ssd_limit = TSS_SIZE - 1;
 504         ssdtosd(&ssd, &ext->ext_tssd);
 505
 506         vm86pcb = pcb;
 507
 508 #if 0
 509         /*
 510          * use whatever is leftover of the vm86 page layout as a
 511          * message buffer so we can capture early output.
 512          */
 513         msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
 514             ctob(3) - sizeof(struct vm86_layout));
 515 #endif
 516 }
 517
 518 vm_offset_t
 519 vm86_getpage(struct vm86context *vmc, int pagenum)
 520 {
 521         int i;
 522
 523         for (i = 0; i < vmc->npages; i++)
 524                 if (vmc->pmap[i].pte_num == pagenum)
 525                         return (vmc->pmap[i].kva);
 526         return (0);
 527 }
 528
 529 vm_offset_t
 530 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
 531 {
 532         int i, flags = 0;
 533
 534         for (i = 0; i < vmc->npages; i++)
 535                 if (vmc->pmap[i].pte_num == pagenum)
 536                         goto bad;
 537
 538         if (vmc->npages == VM86_PMAPSIZE)
 539                 goto bad;                       /* XXX grow map? */
 540
 541         if (kva == 0) {
 542                 kva = (vm_offset_t)kmalloc(PAGE_SIZE, M_TEMP, M_WAITOK);
 543                 flags = VMAP_MALLOC;
 544         }
 545
 546         i = vmc->npages++;
 547         vmc->pmap[i].flags = flags;
 548         vmc->pmap[i].kva = kva;
 549         vmc->pmap[i].pte_num = pagenum;
 550         return (kva);
 551 bad:
 552         panic("vm86_addpage: not enough room, or overlap");
 553 }
 554
 555 static void
 556 vm86_initflags(struct vm86frame *vmf)
 557 {
 558         int eflags = vmf->vmf_eflags;
 559         struct vm86_kernel *vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
 560
 561         if (vm86->vm86_has_vme) {
 562                 eflags = (vmf->vmf_eflags & ~VME_USERCHANGE) |
 563                     (eflags & VME_USERCHANGE) | PSL_VM;
 564         } else {
 565                 vm86->vm86_eflags = eflags;     /* save VIF, VIP */
 566                 eflags = (vmf->vmf_eflags & ~VM_USERCHANGE) |
 567                     (eflags & VM_USERCHANGE) | PSL_VM;
 568         }
 569         vmf->vmf_eflags = eflags | PSL_VM;
 570 }
 571
 572 /*
 573  * called from vm86_bioscall, while in vm86 address space, to finalize setup.
 574  */
 575 void
 576 vm86_prepcall(struct vm86frame *vmf)
 577 {
 578         uintptr_t addr[] = { 0xA00, 0x1000 };   /* code, stack */
 579         u_char intcall[] = {
 580                 CLI, INTn, 0x00, STI, HLT
 581         };
 582
 583         if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) {
 584                 /* interrupt call requested */
 585                 intcall[2] = (u_char)(vmf->vmf_trapno & 0xff);
 586                 memcpy((void *)addr[0], (void *)intcall, sizeof(intcall));
 587                 vmf->vmf_ip = addr[0];
 588                 vmf->vmf_cs = 0;
 589         }
 590         vmf->vmf_sp = addr[1] - 2;              /* keep aligned */
 591         vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = vmf->kernel_gs = 0;
 592         vmf->vmf_ss = 0;
 593         vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
 594         vm86_initflags(vmf);
 595 }
 596
 597 /*
 598  * vm86 trap handler; determines whether routine succeeded or not.
 599  * Called while in vm86 space, returns to calling process.
 600  *
 601  * A MP lock ref is held on entry from trap() and must be released prior
 602  * to returning to the VM86 call.
 603  */
 604 void
 605 vm86_trap(struct vm86frame *vmf, int have_mplock)
 606 {
 607         caddr_t addr;
 608
 609         /* "should not happen" */
 610         if ((vmf->vmf_eflags & PSL_VM) == 0)
 611                 panic("vm86_trap called, but not in vm86 mode");
 612
 613         addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
 614         if (*(u_char *)addr == HLT)
 615                 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
 616         else
 617                 vmf->vmf_trapno = vmf->vmf_trapno << 16;
 618
 619         if (have_mplock)
 620                 rel_mplock();
 621         vm86_biosret(vmf);
 622 }
 623
 624 int
 625 vm86_intcall(int intnum, struct vm86frame *vmf)
 626 {
 627         int error;
 628
 629         if (intnum < 0 || intnum > 0xff)
 630                 return (EINVAL);
 631
 632         crit_enter();
 633         ASSERT_MP_LOCK_HELD();
 634
 635         vm86_setup_timer_fault();
 636         vmf->vmf_trapno = intnum;
 637         error = vm86_bioscall(vmf);
 638
 639         /*
 640          * Yes, this happens, especially with video BIOS calls.  The BIOS
 641          * will sometimes eat timer 2 for lunch, and we need timer 2.
 642          */
 643         if (vm86_blew_up_timer) {
 644                 vm86_blew_up_timer = 0;
 645                 timer_restore();
 646                 if (timer_warn) {
 647                         kprintf("Warning: BIOS played with the 8254, "
 648                                 "resetting it\n");
 649                 }
 650         }
 651         crit_exit();
 652         return(error);
 653 }
 654
 655 /*
 656  * struct vm86context contains the page table to use when making
 657  * vm86 calls.  If intnum is a valid interrupt number (0-255), then
 658  * the "interrupt trampoline" will be used, otherwise we use the
 659  * caller's cs:ip routine.
 660  */
 661 int
 662 vm86_datacall(int intnum, struct vm86frame *vmf, struct vm86context *vmc)
 663 {
 664         pt_entry_t *pte = vm86paddr;
 665         u_int page;
 666         int i, entry, retval;
 667
 668         crit_enter();
 669         ASSERT_MP_LOCK_HELD();
 670
 671         for (i = 0; i < vmc->npages; i++) {
 672                 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
 673                 entry = vmc->pmap[i].pte_num;
 674                 vmc->pmap[i].old_pte = pte[entry];
 675                 pte[entry] = page | PG_V | PG_RW | PG_U;
 676         }
 677
 678         vmf->vmf_trapno = intnum;
 679         retval = vm86_bioscall(vmf);
 680
 681         for (i = 0; i < vmc->npages; i++) {
 682                 entry = vmc->pmap[i].pte_num;
 683                 pte[entry] = vmc->pmap[i].old_pte;
 684         }
 685         crit_exit();
 686         return (retval);
 687 }
 688
 689 vm_offset_t
 690 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off)
 691 {
 692         int i, page;
 693         vm_offset_t addr;
 694
 695         addr = (vm_offset_t)MAKE_ADDR(sel, off);
 696         page = addr >> PAGE_SHIFT;
 697         for (i = 0; i < vmc->npages; i++)
 698                 if (page == vmc->pmap[i].pte_num)
 699                         return (vmc->pmap[i].kva + (addr & PAGE_MASK));
 700         return (0);
 701 }
 702
 703 int
 704 vm86_getptr(struct vm86context *vmc, vm_offset_t kva, u_short *sel,
 705             u_short *off)
 706 {
 707         int i;
 708
 709         for (i = 0; i < vmc->npages; i++)
 710                 if (kva >= vmc->pmap[i].kva &&
 711                     kva < vmc->pmap[i].kva + PAGE_SIZE) {
 712                         *off = kva - vmc->pmap[i].kva;
 713                         *sel = vmc->pmap[i].pte_num << 8;
 714                         return (1);
 715                 }
 716         return (0);
 717         panic("vm86_getptr: address not found");
 718 }
 719
 720 int
 721 vm86_sysarch(struct lwp *lp, char *args)
 722 {
 723         int error = 0;
 724         struct i386_vm86_args ua;
 725         struct vm86_kernel *vm86;
 726
 727         if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
 728                 return (error);
 729
 730         if (lp->lwp_thread->td_pcb->pcb_ext == 0)
 731                 if ((error = i386_extend_pcb(lp)) != 0)
 732                         return (error);
 733         vm86 = &lp->lwp_thread->td_pcb->pcb_ext->ext_vm86;
 734
 735         switch (ua.sub_op) {
 736         case VM86_INIT: {
 737                 struct vm86_init_args sa;
 738
 739                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
 740                         return (error);
 741                 if (cpu_feature & CPUID_VME)
 742                         vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
 743                 else
 744                         vm86->vm86_has_vme = 0;
 745                 vm86->vm86_inited = 1;
 746                 vm86->vm86_debug = sa.debug;
 747                 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
 748                 }
 749                 break;
 750
 751 #if 0
 752         case VM86_SET_VME: {
 753                 struct vm86_vme_args sa;
 754
 755                 if ((cpu_feature & CPUID_VME) == 0)
 756                         return (ENODEV);
 757
 758                 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
 759                         return (error);
 760                 if (sa.state)
 761                         load_cr4(rcr4() | CR4_VME);
 762                 else
 763                         load_cr4(rcr4() & ~CR4_VME);
 764                 }
 765                 break;
 766 #endif
 767
 768         case VM86_GET_VME: {
 769                 struct vm86_vme_args sa;
 770
 771                 sa.state = (rcr4() & CR4_VME ? 1 : 0);
 772                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 773                 }
 774                 break;
 775
 776         case VM86_INTCALL: {
 777                 struct vm86_intcall_args sa;
 778
 779                 if ((error = priv_check_cred(lp->lwp_proc->p_ucred, PRIV_ROOT, 0)))
 780                         return (error);
 781                 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
 782                         return (error);
 783                 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
 784                         return (error);
 785                 error = copyout(&sa, ua.sub_args, sizeof(sa));
 786                 }
 787                 break;
 788
 789         default:
 790                 error = EINVAL;
 791         }
 792         return (error);
 793 }
 794
 795 /*
 796  * Setup the VM86 I/O map to take faults on the timer
 797  */
 798 static void
 799 vm86_setup_timer_fault(void)
 800 {
 801         struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
 802
 803         vml->vml_iomap[TIMER_MODE >> 3] |= 1 << (TIMER_MODE & 7);
 804         vml->vml_iomap[TIMER_CNTR0 >> 3] |= 1 << (TIMER_CNTR0 & 7);
 805         vml->vml_iomap[TIMER_CNTR1 >> 3] |= 1 << (TIMER_CNTR1 & 7);
 806         vml->vml_iomap[TIMER_CNTR2 >> 3] |= 1 << (TIMER_CNTR2 & 7);
 807 }
 808
 809 /*
 810  * Setup the VM86 I/O map to not fault on the timer
 811  */
 812 static void
 813 vm86_clear_timer_fault(void)
 814 {
 815         struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
 816
 817         vml->vml_iomap[TIMER_MODE >> 3] &= ~(1 << (TIMER_MODE & 7));
 818         vml->vml_iomap[TIMER_CNTR0 >> 3] &= ~(1 << (TIMER_CNTR0 & 7));
 819         vml->vml_iomap[TIMER_CNTR1 >> 3] &= ~(1 << (TIMER_CNTR1 & 7));
 820         vml->vml_iomap[TIMER_CNTR2 >> 3] &= ~(1 << (TIMER_CNTR2 & 7));
 821 }
 822