Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/vm86.c
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1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1997 Jonathan Lemon 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/priv.h> 35 #include <sys/proc.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/mutex.h> 39 40 #include <vm/vm.h> 41 #include <vm/pmap.h> 42 #include <vm/vm_map.h> 43 #include <vm/vm_page.h> 44 45 #include <machine/md_var.h> 46 #include <machine/pcb.h> 47 #include <machine/pcb_ext.h> 48 #include <machine/psl.h> 49 #include <machine/specialreg.h> 50 #include <machine/sysarch.h> 51 52 extern int vm86pa; 53 extern struct pcb *vm86pcb; 54 55 static struct mtx vm86_lock; 56 57 extern int vm86_bioscall(struct vm86frame *); 58 extern void vm86_biosret(struct vm86frame *); 59 60 void vm86_prepcall(struct vm86frame *); 61 62 struct system_map { 63 int type; 64 vm_offset_t start; 65 vm_offset_t end; 66 }; 67 68 #define HLT 0xf4 69 #define CLI 0xfa 70 #define STI 0xfb 71 #define PUSHF 0x9c 72 #define POPF 0x9d 73 #define INTn 0xcd 74 #define IRET 0xcf 75 #define CALLm 0xff 76 #define OPERAND_SIZE_PREFIX 0x66 77 #define ADDRESS_SIZE_PREFIX 0x67 78 #define PUSH_MASK ~(PSL_VM | PSL_RF | PSL_I) 79 #define POP_MASK ~(PSL_VIP | PSL_VIF | PSL_VM | PSL_RF | PSL_IOPL) 80 81 static int 82 vm86_suword16(volatile void *base, int word) 83 { 84 85 if (curthread->td_critnest != 0) { 86 *(volatile uint16_t *)base = word; 87 return (0); 88 } 89 return (suword16(base, word)); 90 } 91 92 static int 93 vm86_suword(volatile void *base, long word) 94 { 95 96 if (curthread->td_critnest != 0) { 97 *(volatile long *)base = word; 98 return (0); 99 } 100 return (suword(base, word)); 101 } 102 103 static int 104 vm86_fubyte(volatile const void *base) 105 { 106 107 if (curthread->td_critnest != 0) 108 return (*(volatile const u_char *)base); 109 return (fubyte(base)); 110 } 111 112 static int 113 vm86_fuword16(volatile const void *base) 114 { 115 116 if (curthread->td_critnest != 0) 117 return (*(volatile const uint16_t *)base); 118 return (fuword16(base)); 119 } 120 121 static long 122 vm86_fuword(volatile const void *base) 123 { 124 125 if (curthread->td_critnest != 0) 126 return (*(volatile const long *)base); 127 return (fuword(base)); 128 } 129 130 static __inline caddr_t 131 MAKE_ADDR(u_short sel, u_short off) 132 { 133 return ((caddr_t)((sel << 4) + off)); 134 } 135 136 static __inline void 137 GET_VEC(u_int vec, u_short *sel, u_short *off) 138 { 139 *sel = vec >> 16; 140 *off = vec & 0xffff; 141 } 142 143 static __inline u_int 144 MAKE_VEC(u_short sel, u_short off) 145 { 146 return ((sel << 16) | off); 147 } 148 149 static __inline void 150 PUSH(u_short x, struct vm86frame *vmf) 151 { 152 vmf->vmf_sp -= 2; 153 vm86_suword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x); 154 } 155 156 static __inline void 157 PUSHL(u_int x, struct vm86frame *vmf) 158 { 159 vmf->vmf_sp -= 4; 160 vm86_suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x); 161 } 162 163 static __inline u_short 164 POP(struct vm86frame *vmf) 165 { 166 u_short x = vm86_fuword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp)); 167 168 vmf->vmf_sp += 2; 169 return (x); 170 } 171 172 static __inline u_int 173 POPL(struct vm86frame *vmf) 174 { 175 u_int x = vm86_fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp)); 176 177 vmf->vmf_sp += 4; 178 return (x); 179 } 180 181 int 182 vm86_emulate(struct vm86frame *vmf) 183 { 184 struct vm86_kernel *vm86; 185 caddr_t addr; 186 u_char i_byte; 187 u_int temp_flags; 188 int inc_ip = 1; 189 int retcode = 0; 190 191 /* 192 * pcb_ext contains the address of the extension area, or zero if 193 * the extension is not present. (This check should not be needed, 194 * as we can't enter vm86 mode until we set up an extension area) 195 */ 196 if (curpcb->pcb_ext == 0) 197 return (SIGBUS); 198 vm86 = &curpcb->pcb_ext->ext_vm86; 199 200 if (vmf->vmf_eflags & PSL_T) 201 retcode = SIGTRAP; 202 203 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip); 204 i_byte = vm86_fubyte(addr); 205 if (i_byte == ADDRESS_SIZE_PREFIX) { 206 i_byte = vm86_fubyte(++addr); 207 inc_ip++; 208 } 209 210 if (vm86->vm86_has_vme) { 211 switch (i_byte) { 212 case OPERAND_SIZE_PREFIX: 213 i_byte = vm86_fubyte(++addr); 214 inc_ip++; 215 switch (i_byte) { 216 case PUSHF: 217 if (vmf->vmf_eflags & PSL_VIF) 218 PUSHL((vmf->vmf_eflags & PUSH_MASK) 219 | PSL_IOPL | PSL_I, vmf); 220 else 221 PUSHL((vmf->vmf_eflags & PUSH_MASK) 222 | PSL_IOPL, vmf); 223 vmf->vmf_ip += inc_ip; 224 return (retcode); 225 226 case POPF: 227 temp_flags = POPL(vmf) & POP_MASK; 228 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK) 229 | temp_flags | PSL_VM | PSL_I; 230 vmf->vmf_ip += inc_ip; 231 if (temp_flags & PSL_I) { 232 vmf->vmf_eflags |= PSL_VIF; 233 if (vmf->vmf_eflags & PSL_VIP) 234 break; 235 } else { 236 vmf->vmf_eflags &= ~PSL_VIF; 237 } 238 return (retcode); 239 } 240 break; 241 242 /* VME faults here if VIP is set, but does not set VIF. */ 243 case STI: 244 vmf->vmf_eflags |= PSL_VIF; 245 vmf->vmf_ip += inc_ip; 246 if ((vmf->vmf_eflags & PSL_VIP) == 0) { 247 uprintf("fatal sti\n"); 248 return (SIGKILL); 249 } 250 break; 251 252 /* VME if no redirection support */ 253 case INTn: 254 break; 255 256 /* VME if trying to set PSL_T, or PSL_I when VIP is set */ 257 case POPF: 258 temp_flags = POP(vmf) & POP_MASK; 259 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK) 260 | temp_flags | PSL_VM | PSL_I; 261 vmf->vmf_ip += inc_ip; 262 if (temp_flags & PSL_I) { 263 vmf->vmf_eflags |= PSL_VIF; 264 if (vmf->vmf_eflags & PSL_VIP) 265 break; 266 } else { 267 vmf->vmf_eflags &= ~PSL_VIF; 268 } 269 return (retcode); 270 271 /* VME if trying to set PSL_T, or PSL_I when VIP is set */ 272 case IRET: 273 vmf->vmf_ip = POP(vmf); 274 vmf->vmf_cs = POP(vmf); 275 temp_flags = POP(vmf) & POP_MASK; 276 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK) 277 | temp_flags | PSL_VM | PSL_I; 278 if (temp_flags & PSL_I) { 279 vmf->vmf_eflags |= PSL_VIF; 280 if (vmf->vmf_eflags & PSL_VIP) 281 break; 282 } else { 283 vmf->vmf_eflags &= ~PSL_VIF; 284 } 285 return (retcode); 286 } 287 return (SIGBUS); 288 } 289 290 switch (i_byte) { 291 case OPERAND_SIZE_PREFIX: 292 i_byte = vm86_fubyte(++addr); 293 inc_ip++; 294 switch (i_byte) { 295 case PUSHF: 296 if (vm86->vm86_eflags & PSL_VIF) 297 PUSHL((vmf->vmf_flags & PUSH_MASK) 298 | PSL_IOPL | PSL_I, vmf); 299 else 300 PUSHL((vmf->vmf_flags & PUSH_MASK) 301 | PSL_IOPL, vmf); 302 vmf->vmf_ip += inc_ip; 303 return (retcode); 304 305 case POPF: 306 temp_flags = POPL(vmf) & POP_MASK; 307 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK) 308 | temp_flags | PSL_VM | PSL_I; 309 vmf->vmf_ip += inc_ip; 310 if (temp_flags & PSL_I) { 311 vm86->vm86_eflags |= PSL_VIF; 312 if (vm86->vm86_eflags & PSL_VIP) 313 break; 314 } else { 315 vm86->vm86_eflags &= ~PSL_VIF; 316 } 317 return (retcode); 318 } 319 return (SIGBUS); 320 321 case CLI: 322 vm86->vm86_eflags &= ~PSL_VIF; 323 vmf->vmf_ip += inc_ip; 324 return (retcode); 325 326 case STI: 327 /* if there is a pending interrupt, go to the emulator */ 328 vm86->vm86_eflags |= PSL_VIF; 329 vmf->vmf_ip += inc_ip; 330 if (vm86->vm86_eflags & PSL_VIP) 331 break; 332 return (retcode); 333 334 case PUSHF: 335 if (vm86->vm86_eflags & PSL_VIF) 336 PUSH((vmf->vmf_flags & PUSH_MASK) 337 | PSL_IOPL | PSL_I, vmf); 338 else 339 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf); 340 vmf->vmf_ip += inc_ip; 341 return (retcode); 342 343 case INTn: 344 i_byte = vm86_fubyte(addr + 1); 345 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0) 346 break; 347 if (vm86->vm86_eflags & PSL_VIF) 348 PUSH((vmf->vmf_flags & PUSH_MASK) 349 | PSL_IOPL | PSL_I, vmf); 350 else 351 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf); 352 PUSH(vmf->vmf_cs, vmf); 353 PUSH(vmf->vmf_ip + inc_ip + 1, vmf); /* increment IP */ 354 GET_VEC(vm86_fuword((caddr_t)(i_byte * 4)), 355 &vmf->vmf_cs, &vmf->vmf_ip); 356 vmf->vmf_flags &= ~PSL_T; 357 vm86->vm86_eflags &= ~PSL_VIF; 358 return (retcode); 359 360 case IRET: 361 vmf->vmf_ip = POP(vmf); 362 vmf->vmf_cs = POP(vmf); 363 temp_flags = POP(vmf) & POP_MASK; 364 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK) 365 | temp_flags | PSL_VM | PSL_I; 366 if (temp_flags & PSL_I) { 367 vm86->vm86_eflags |= PSL_VIF; 368 if (vm86->vm86_eflags & PSL_VIP) 369 break; 370 } else { 371 vm86->vm86_eflags &= ~PSL_VIF; 372 } 373 return (retcode); 374 375 case POPF: 376 temp_flags = POP(vmf) & POP_MASK; 377 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK) 378 | temp_flags | PSL_VM | PSL_I; 379 vmf->vmf_ip += inc_ip; 380 if (temp_flags & PSL_I) { 381 vm86->vm86_eflags |= PSL_VIF; 382 if (vm86->vm86_eflags & PSL_VIP) 383 break; 384 } else { 385 vm86->vm86_eflags &= ~PSL_VIF; 386 } 387 return (retcode); 388 } 389 return (SIGBUS); 390 } 391 392 #define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE) 393 #define INTMAP_SIZE 32 394 #define IOMAP_SIZE ctob(IOPAGES) 395 #define TSS_SIZE \ 396 (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \ 397 INTMAP_SIZE + IOMAP_SIZE + 1) 398 399 struct vm86_layout_pae { 400 uint64_t vml_pgtbl[PGTABLE_SIZE]; 401 struct pcb vml_pcb; 402 struct pcb_ext vml_ext; 403 char vml_intmap[INTMAP_SIZE]; 404 char vml_iomap[IOMAP_SIZE]; 405 char vml_iomap_trailer; 406 }; 407 408 struct vm86_layout_nopae { 409 uint32_t vml_pgtbl[PGTABLE_SIZE]; 410 struct pcb vml_pcb; 411 struct pcb_ext vml_ext; 412 char vml_intmap[INTMAP_SIZE]; 413 char vml_iomap[IOMAP_SIZE]; 414 char vml_iomap_trailer; 415 }; 416 417 _Static_assert(sizeof(struct vm86_layout_pae) <= ctob(3), 418 "struct vm86_layout_pae exceeds space allocated in locore.s"); 419 _Static_assert(sizeof(struct vm86_layout_nopae) <= ctob(3), 420 "struct vm86_layout_nopae exceeds space allocated in locore.s"); 421 422 static void 423 vm86_initialize_pae(void) 424 { 425 int i; 426 u_int *addr; 427 struct vm86_layout_pae *vml; 428 struct pcb *pcb; 429 struct pcb_ext *ext; 430 struct soft_segment_descriptor ssd = { 431 0, /* segment base address (overwritten) */ 432 0, /* length (overwritten) */ 433 SDT_SYS386TSS, /* segment type */ 434 0, /* priority level */ 435 1, /* descriptor present */ 436 0, 0, 437 0, /* default 16 size */ 438 0 /* granularity */ 439 }; 440 441 /* 442 * Below is the memory layout that we use for the vm86 region. 443 * 444 * +--------+ 445 * | | 446 * | | 447 * | page 0 | 448 * | | +--------+ 449 * | | | stack | 450 * +--------+ +--------+ <--------- vm86paddr 451 * | | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes 452 * | | +--------+ 453 * | | | PCB | size: ~240 bytes 454 * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS) 455 * | | +--------+ 456 * | | |int map | 457 * | | +--------+ 458 * +--------+ | | 459 * | page 2 | | I/O | 460 * +--------+ | bitmap | 461 * | page 3 | | | 462 * | | +--------+ 463 * +--------+ 464 */ 465 466 /* 467 * A rudimentary PCB must be installed, in order to get to the 468 * PCB extension area. We use the PCB area as a scratchpad for 469 * data storage, the layout of which is shown below. 470 * 471 * pcb_esi = new PTD entry 0 472 * pcb_ebp = pointer to frame on vm86 stack 473 * pcb_esp = stack frame pointer at time of switch 474 * pcb_ebx = va of vm86 page table 475 * pcb_eip = argument pointer to initial call 476 * pcb_vm86[0] = saved TSS descriptor, word 0 477 * pcb_vm86[1] = saved TSS descriptor, word 1 478 */ 479 #define new_ptd pcb_esi 480 #define vm86_frame pcb_ebp 481 #define pgtable_va pcb_ebx 482 483 vml = (struct vm86_layout_pae *)vm86paddr; 484 pcb = &vml->vml_pcb; 485 ext = &vml->vml_ext; 486 487 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF); 488 489 bzero(pcb, sizeof(struct pcb)); 490 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U; 491 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame); 492 pcb->pgtable_va = vm86paddr; 493 pcb->pcb_flags = PCB_VM86CALL; 494 pcb->pcb_ext = ext; 495 496 bzero(ext, sizeof(struct pcb_ext)); 497 ext->ext_tss.tss_esp0 = vm86paddr; 498 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL); 499 ext->ext_tss.tss_ioopt = 500 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16; 501 ext->ext_iomap = vml->vml_iomap; 502 ext->ext_vm86.vm86_intmap = vml->vml_intmap; 503 504 if (cpu_feature & CPUID_VME) 505 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0); 506 507 addr = (u_int *)ext->ext_vm86.vm86_intmap; 508 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++) 509 *addr++ = 0; 510 vml->vml_iomap_trailer = 0xff; 511 512 ssd.ssd_base = (u_int)&ext->ext_tss; 513 ssd.ssd_limit = TSS_SIZE - 1; 514 ssdtosd(&ssd, &ext->ext_tssd); 515 516 vm86pcb = pcb; 517 518 #if 0 519 /* 520 * use whatever is leftover of the vm86 page layout as a 521 * message buffer so we can capture early output. 522 */ 523 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout), 524 ctob(3) - sizeof(struct vm86_layout)); 525 #endif 526 } 527 528 static void 529 vm86_initialize_nopae(void) 530 { 531 int i; 532 u_int *addr; 533 struct vm86_layout_nopae *vml; 534 struct pcb *pcb; 535 struct pcb_ext *ext; 536 struct soft_segment_descriptor ssd = { 537 0, /* segment base address (overwritten) */ 538 0, /* length (overwritten) */ 539 SDT_SYS386TSS, /* segment type */ 540 0, /* priority level */ 541 1, /* descriptor present */ 542 0, 0, 543 0, /* default 16 size */ 544 0 /* granularity */ 545 }; 546 547 vml = (struct vm86_layout_nopae *)vm86paddr; 548 pcb = &vml->vml_pcb; 549 ext = &vml->vml_ext; 550 551 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF); 552 553 bzero(pcb, sizeof(struct pcb)); 554 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U; 555 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame); 556 pcb->pgtable_va = vm86paddr; 557 pcb->pcb_flags = PCB_VM86CALL; 558 pcb->pcb_ext = ext; 559 560 bzero(ext, sizeof(struct pcb_ext)); 561 ext->ext_tss.tss_esp0 = vm86paddr; 562 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL); 563 ext->ext_tss.tss_ioopt = 564 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16; 565 ext->ext_iomap = vml->vml_iomap; 566 ext->ext_vm86.vm86_intmap = vml->vml_intmap; 567 568 if (cpu_feature & CPUID_VME) 569 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0); 570 571 addr = (u_int *)ext->ext_vm86.vm86_intmap; 572 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++) 573 *addr++ = 0; 574 vml->vml_iomap_trailer = 0xff; 575 576 ssd.ssd_base = (u_int)&ext->ext_tss; 577 ssd.ssd_limit = TSS_SIZE - 1; 578 ssdtosd(&ssd, &ext->ext_tssd); 579 580 vm86pcb = pcb; 581 582 #if 0 583 /* 584 * use whatever is leftover of the vm86 page layout as a 585 * message buffer so we can capture early output. 586 */ 587 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout), 588 ctob(3) - sizeof(struct vm86_layout)); 589 #endif 590 } 591 592 void 593 vm86_initialize(void) 594 { 595 596 if (pae_mode) 597 vm86_initialize_pae(); 598 else 599 vm86_initialize_nopae(); 600 } 601 602 vm_offset_t 603 vm86_getpage(struct vm86context *vmc, int pagenum) 604 { 605 int i; 606 607 for (i = 0; i < vmc->npages; i++) 608 if (vmc->pmap[i].pte_num == pagenum) 609 return (vmc->pmap[i].kva); 610 return (0); 611 } 612 613 vm_offset_t 614 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva) 615 { 616 int i, flags = 0; 617 618 for (i = 0; i < vmc->npages; i++) 619 if (vmc->pmap[i].pte_num == pagenum) 620 goto overlap; 621 622 if (vmc->npages == VM86_PMAPSIZE) 623 goto full; /* XXX grow map? */ 624 625 if (kva == 0) { 626 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK); 627 flags = VMAP_MALLOC; 628 } 629 630 i = vmc->npages++; 631 vmc->pmap[i].flags = flags; 632 vmc->pmap[i].kva = kva; 633 vmc->pmap[i].pte_num = pagenum; 634 return (kva); 635 overlap: 636 panic("vm86_addpage: overlap"); 637 full: 638 panic("vm86_addpage: not enough room"); 639 } 640 641 /* 642 * called from vm86_bioscall, while in vm86 address space, to finalize setup. 643 */ 644 void 645 vm86_prepcall(struct vm86frame *vmf) 646 { 647 struct vm86_kernel *vm86; 648 uint32_t *stack; 649 uint8_t *code; 650 651 code = (void *)0xa00; 652 stack = (void *)(0x1000 - 2); /* keep aligned */ 653 if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) { 654 /* interrupt call requested */ 655 code[0] = INTn; 656 code[1] = vmf->vmf_trapno & 0xff; 657 code[2] = HLT; 658 vmf->vmf_ip = (uintptr_t)code; 659 vmf->vmf_cs = 0; 660 } else { 661 code[0] = HLT; 662 stack--; 663 stack[0] = MAKE_VEC(0, (uintptr_t)code); 664 } 665 vmf->vmf_sp = (uintptr_t)stack; 666 vmf->vmf_ss = 0; 667 vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = 0; 668 vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER; 669 670 vm86 = &curpcb->pcb_ext->ext_vm86; 671 if (!vm86->vm86_has_vme) 672 vm86->vm86_eflags = vmf->vmf_eflags; /* save VIF, VIP */ 673 } 674 675 /* 676 * vm86 trap handler; determines whether routine succeeded or not. 677 * Called while in vm86 space, returns to calling process. 678 */ 679 void 680 vm86_trap(struct vm86frame *vmf) 681 { 682 void (*p)(struct vm86frame *); 683 caddr_t addr; 684 685 /* "should not happen" */ 686 if ((vmf->vmf_eflags & PSL_VM) == 0) 687 panic("vm86_trap called, but not in vm86 mode"); 688 689 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip); 690 if (*(u_char *)addr == HLT) 691 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C; 692 else 693 vmf->vmf_trapno = vmf->vmf_trapno << 16; 694 695 p = (void (*)(struct vm86frame *))((uintptr_t)vm86_biosret + 696 setidt_disp); 697 p(vmf); 698 } 699 700 int 701 vm86_intcall(int intnum, struct vm86frame *vmf) 702 { 703 int (*p)(struct vm86frame *); 704 int retval; 705 706 if (intnum < 0 || intnum > 0xff) 707 return (EINVAL); 708 709 vmf->vmf_trapno = intnum; 710 p = (int (*)(struct vm86frame *))((uintptr_t)vm86_bioscall + 711 setidt_disp); 712 mtx_lock(&vm86_lock); 713 critical_enter(); 714 retval = p(vmf); 715 critical_exit(); 716 mtx_unlock(&vm86_lock); 717 return (retval); 718 } 719 720 /* 721 * struct vm86context contains the page table to use when making 722 * vm86 calls. If intnum is a valid interrupt number (0-255), then 723 * the "interrupt trampoline" will be used, otherwise we use the 724 * caller's cs:ip routine. 725 */ 726 int 727 vm86_datacall(int intnum, struct vm86frame *vmf, struct vm86context *vmc) 728 { 729 uint64_t *pte_pae; 730 uint32_t *pte_nopae; 731 int (*p)(struct vm86frame *); 732 vm_paddr_t page; 733 int i, entry, retval; 734 735 mtx_lock(&vm86_lock); 736 if (pae_mode) { 737 pte_pae = (uint64_t *)vm86paddr; 738 for (i = 0; i < vmc->npages; i++) { 739 page = vtophys(vmc->pmap[i].kva & PG_FRAME_PAE); 740 entry = vmc->pmap[i].pte_num; 741 vmc->pmap[i].old_pte = pte_pae[entry]; 742 pte_pae[entry] = page | PG_V | PG_RW | PG_U; 743 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva); 744 } 745 } else { 746 pte_nopae = (uint32_t *)vm86paddr; 747 for (i = 0; i < vmc->npages; i++) { 748 page = vtophys(vmc->pmap[i].kva & PG_FRAME_NOPAE); 749 entry = vmc->pmap[i].pte_num; 750 vmc->pmap[i].old_pte = pte_nopae[entry]; 751 pte_nopae[entry] = page | PG_V | PG_RW | PG_U; 752 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva); 753 } 754 } 755 756 vmf->vmf_trapno = intnum; 757 p = (int (*)(struct vm86frame *))((uintptr_t)vm86_bioscall + 758 setidt_disp); 759 critical_enter(); 760 retval = p(vmf); 761 critical_exit(); 762 763 if (pae_mode) { 764 for (i = 0; i < vmc->npages; i++) { 765 entry = vmc->pmap[i].pte_num; 766 pte_pae[entry] = vmc->pmap[i].old_pte; 767 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva); 768 } 769 } else { 770 for (i = 0; i < vmc->npages; i++) { 771 entry = vmc->pmap[i].pte_num; 772 pte_nopae[entry] = vmc->pmap[i].old_pte; 773 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva); 774 } 775 } 776 mtx_unlock(&vm86_lock); 777 778 return (retval); 779 } 780 781 vm_offset_t 782 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off) 783 { 784 int i, page; 785 vm_offset_t addr; 786 787 addr = (vm_offset_t)MAKE_ADDR(sel, off); 788 page = addr >> PAGE_SHIFT; 789 for (i = 0; i < vmc->npages; i++) 790 if (page == vmc->pmap[i].pte_num) 791 return (vmc->pmap[i].kva + (addr & PAGE_MASK)); 792 return (0); 793 } 794 795 int 796 vm86_getptr(struct vm86context *vmc, vm_offset_t kva, u_short *sel, 797 u_short *off) 798 { 799 int i; 800 801 for (i = 0; i < vmc->npages; i++) 802 if (kva >= vmc->pmap[i].kva && 803 kva < vmc->pmap[i].kva + PAGE_SIZE) { 804 *off = kva - vmc->pmap[i].kva; 805 *sel = vmc->pmap[i].pte_num << 8; 806 return (1); 807 } 808 return (0); 809 } 810 811 int 812 vm86_sysarch(struct thread *td, char *args) 813 { 814 int error = 0; 815 struct i386_vm86_args ua; 816 struct vm86_kernel *vm86; 817 818 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0) 819 return (error); 820 821 if (td->td_pcb->pcb_ext == 0) 822 if ((error = i386_extend_pcb(td)) != 0) 823 return (error); 824 vm86 = &td->td_pcb->pcb_ext->ext_vm86; 825 826 switch (ua.sub_op) { 827 case VM86_INIT: { 828 struct vm86_init_args sa; 829 830 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0) 831 return (error); 832 if (cpu_feature & CPUID_VME) 833 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0); 834 else 835 vm86->vm86_has_vme = 0; 836 vm86->vm86_inited = 1; 837 vm86->vm86_debug = sa.debug; 838 bcopy(&sa.int_map, vm86->vm86_intmap, 32); 839 } 840 break; 841 842 #if 0 843 case VM86_SET_VME: { 844 struct vm86_vme_args sa; 845 846 if ((cpu_feature & CPUID_VME) == 0) 847 return (ENODEV); 848 849 if (error = copyin(ua.sub_args, &sa, sizeof(sa))) 850 return (error); 851 if (sa.state) 852 load_cr4(rcr4() | CR4_VME); 853 else 854 load_cr4(rcr4() & ~CR4_VME); 855 } 856 break; 857 #endif 858 859 case VM86_GET_VME: { 860 struct vm86_vme_args sa; 861 862 sa.state = (rcr4() & CR4_VME ? 1 : 0); 863 error = copyout(&sa, ua.sub_args, sizeof(sa)); 864 } 865 break; 866 867 case VM86_INTCALL: { 868 struct vm86_intcall_args sa; 869 870 if ((error = priv_check(td, PRIV_VM86_INTCALL))) 871 return (error); 872 if ((error = copyin(ua.sub_args, &sa, sizeof(sa)))) 873 return (error); 874 if ((error = vm86_intcall(sa.intnum, &sa.vmf))) 875 return (error); 876 error = copyout(&sa, ua.sub_args, sizeof(sa)); 877 } 878 break; 879 880 default: 881 error = EINVAL; 882 } 883 return (error); 884 }
Cache object: 605c41dce1ece2c0789649f90c662e8a
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