2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 1997 Jonathan Lemon
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
42 #include <vm/vm_map.h>
43 #include <vm/vm_page.h>
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>
53 extern struct pcb *vm86pcb;
55 static struct mtx vm86_lock;
57 extern int vm86_bioscall(struct vm86frame *);
58 extern void vm86_biosret(struct vm86frame *);
60 void vm86_prepcall(struct vm86frame *);
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)
81 static __inline caddr_t
82 MAKE_ADDR(u_short sel, u_short off)
84 return ((caddr_t)((sel << 4) + off));
88 GET_VEC(u_int vec, u_short *sel, u_short *off)
95 MAKE_VEC(u_short sel, u_short off)
97 return ((sel << 16) | off);
101 PUSH(u_short x, struct vm86frame *vmf)
104 suword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
108 PUSHL(u_int x, struct vm86frame *vmf)
111 suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
114 static __inline u_short
115 POP(struct vm86frame *vmf)
117 u_short x = fuword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
123 static __inline u_int
124 POPL(struct vm86frame *vmf)
126 u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
133 vm86_emulate(struct vm86frame *vmf)
135 struct vm86_kernel *vm86;
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)
147 if (curpcb->pcb_ext == 0)
149 vm86 = &curpcb->pcb_ext->ext_vm86;
151 if (vmf->vmf_eflags & PSL_T)
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);
161 if (vm86->vm86_has_vme) {
163 case OPERAND_SIZE_PREFIX:
164 i_byte = fubyte(++addr);
168 if (vmf->vmf_eflags & PSL_VIF)
169 PUSHL((vmf->vmf_eflags & PUSH_MASK)
170 | PSL_IOPL | PSL_I, vmf);
172 PUSHL((vmf->vmf_eflags & PUSH_MASK)
174 vmf->vmf_ip += inc_ip;
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)
187 vmf->vmf_eflags &= ~PSL_VIF;
193 /* VME faults here if VIP is set, but does not set VIF. */
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");
203 /* VME if no redirection support */
207 /* VME if trying to set PSL_T, or PSL_I when VIP is set */
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)
218 vmf->vmf_eflags &= ~PSL_VIF;
222 /* VME if trying to set PSL_T, or PSL_I when VIP is set */
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)
234 vmf->vmf_eflags &= ~PSL_VIF;
243 case OPERAND_SIZE_PREFIX:
244 i_byte = fubyte(++addr);
248 if (vm86->vm86_eflags & PSL_VIF)
249 PUSHL((vmf->vmf_flags & PUSH_MASK)
250 | PSL_IOPL | PSL_I, vmf);
252 PUSHL((vmf->vmf_flags & PUSH_MASK)
254 vmf->vmf_ip += inc_ip;
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)
267 vm86->vm86_eflags &= ~PSL_VIF;
274 vm86->vm86_eflags &= ~PSL_VIF;
275 vmf->vmf_ip += inc_ip;
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)
287 if (vm86->vm86_eflags & PSL_VIF)
288 PUSH((vmf->vmf_flags & PUSH_MASK)
289 | PSL_IOPL | PSL_I, vmf);
291 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
292 vmf->vmf_ip += inc_ip;
296 i_byte = fubyte(addr + 1);
297 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
299 if (vm86->vm86_eflags & PSL_VIF)
300 PUSH((vmf->vmf_flags & PUSH_MASK)
301 | PSL_IOPL | PSL_I, vmf);
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;
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)
323 vm86->vm86_eflags &= ~PSL_VIF;
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)
337 vm86->vm86_eflags &= ~PSL_VIF;
344 #define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE)
345 #define INTMAP_SIZE 32
346 #define IOMAP_SIZE ctob(IOPAGES)
348 (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
349 INTMAP_SIZE + IOMAP_SIZE + 1)
352 pt_entry_t vml_pgtbl[PGTABLE_SIZE];
354 struct pcb_ext vml_ext;
355 char vml_intmap[INTMAP_SIZE];
356 char vml_iomap[IOMAP_SIZE];
357 char vml_iomap_trailer;
361 vm86_initialize(void)
365 struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
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 */
375 0, /* default 16 size */
380 * this should be a compile time error, but cpp doesn't grok sizeof().
382 if (sizeof(struct vm86_layout) > ctob(3))
383 panic("struct vm86_layout exceeds space allocated in locore.s");
386 * Below is the memory layout that we use for the vm86 region.
394 * +--------+ +--------+ <--------- vm86paddr
395 * | | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
397 * | | | PCB | size: ~240 bytes
398 * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
404 * +--------+ | bitmap |
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.
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
423 #define new_ptd pcb_esi
424 #define vm86_frame pcb_ebp
425 #define pgtable_va pcb_ebx
430 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF);
432 bzero(pcb, sizeof(struct pcb));
433 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
434 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
435 pcb->pgtable_va = vm86paddr;
436 pcb->pcb_flags = PCB_VM86CALL;
439 bzero(ext, sizeof(struct pcb_ext));
440 ext->ext_tss.tss_esp0 = vm86paddr;
441 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
442 ext->ext_tss.tss_ioopt =
443 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
444 ext->ext_iomap = vml->vml_iomap;
445 ext->ext_vm86.vm86_intmap = vml->vml_intmap;
447 if (cpu_feature & CPUID_VME)
448 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
450 addr = (u_int *)ext->ext_vm86.vm86_intmap;
451 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
453 vml->vml_iomap_trailer = 0xff;
455 ssd.ssd_base = (u_int)&ext->ext_tss;
456 ssd.ssd_limit = TSS_SIZE - 1;
457 ssdtosd(&ssd, &ext->ext_tssd);
463 * use whatever is leftover of the vm86 page layout as a
464 * message buffer so we can capture early output.
466 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
467 ctob(3) - sizeof(struct vm86_layout));
472 vm86_getpage(struct vm86context *vmc, int pagenum)
476 for (i = 0; i < vmc->npages; i++)
477 if (vmc->pmap[i].pte_num == pagenum)
478 return (vmc->pmap[i].kva);
483 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
487 for (i = 0; i < vmc->npages; i++)
488 if (vmc->pmap[i].pte_num == pagenum)
491 if (vmc->npages == VM86_PMAPSIZE)
492 goto full; /* XXX grow map? */
495 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
500 vmc->pmap[i].flags = flags;
501 vmc->pmap[i].kva = kva;
502 vmc->pmap[i].pte_num = pagenum;
505 panic("vm86_addpage: overlap");
507 panic("vm86_addpage: not enough room");
511 * called from vm86_bioscall, while in vm86 address space, to finalize setup.
514 vm86_prepcall(struct vm86frame *vmf)
516 struct vm86_kernel *vm86;
520 code = (void *)0xa00;
521 stack = (void *)(0x1000 - 2); /* keep aligned */
522 if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) {
523 /* interrupt call requested */
525 code[1] = vmf->vmf_trapno & 0xff;
527 vmf->vmf_ip = (uintptr_t)code;
532 stack[0] = MAKE_VEC(0, (uintptr_t)code);
534 vmf->vmf_sp = (uintptr_t)stack;
536 vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = 0;
537 vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
539 vm86 = &curpcb->pcb_ext->ext_vm86;
540 if (!vm86->vm86_has_vme)
541 vm86->vm86_eflags = vmf->vmf_eflags; /* save VIF, VIP */
545 * vm86 trap handler; determines whether routine succeeded or not.
546 * Called while in vm86 space, returns to calling process.
549 vm86_trap(struct vm86frame *vmf)
553 /* "should not happen" */
554 if ((vmf->vmf_eflags & PSL_VM) == 0)
555 panic("vm86_trap called, but not in vm86 mode");
557 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
558 if (*(u_char *)addr == HLT)
559 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
561 vmf->vmf_trapno = vmf->vmf_trapno << 16;
567 vm86_intcall(int intnum, struct vm86frame *vmf)
571 if (intnum < 0 || intnum > 0xff)
574 vmf->vmf_trapno = intnum;
575 mtx_lock(&vm86_lock);
577 retval = vm86_bioscall(vmf);
579 mtx_unlock(&vm86_lock);
584 * struct vm86context contains the page table to use when making
585 * vm86 calls. If intnum is a valid interrupt number (0-255), then
586 * the "interrupt trampoline" will be used, otherwise we use the
587 * caller's cs:ip routine.
590 vm86_datacall(int intnum, struct vm86frame *vmf, struct vm86context *vmc)
592 pt_entry_t *pte = (pt_entry_t *)vm86paddr;
594 int i, entry, retval;
596 mtx_lock(&vm86_lock);
597 for (i = 0; i < vmc->npages; i++) {
598 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
599 entry = vmc->pmap[i].pte_num;
600 vmc->pmap[i].old_pte = pte[entry];
601 pte[entry] = page | PG_V | PG_RW | PG_U;
602 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
605 vmf->vmf_trapno = intnum;
607 retval = vm86_bioscall(vmf);
610 for (i = 0; i < vmc->npages; i++) {
611 entry = vmc->pmap[i].pte_num;
612 pte[entry] = vmc->pmap[i].old_pte;
613 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
615 mtx_unlock(&vm86_lock);
621 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off)
626 addr = (vm_offset_t)MAKE_ADDR(sel, off);
627 page = addr >> PAGE_SHIFT;
628 for (i = 0; i < vmc->npages; i++)
629 if (page == vmc->pmap[i].pte_num)
630 return (vmc->pmap[i].kva + (addr & PAGE_MASK));
635 vm86_getptr(struct vm86context *vmc, vm_offset_t kva, u_short *sel,
640 for (i = 0; i < vmc->npages; i++)
641 if (kva >= vmc->pmap[i].kva &&
642 kva < vmc->pmap[i].kva + PAGE_SIZE) {
643 *off = kva - vmc->pmap[i].kva;
644 *sel = vmc->pmap[i].pte_num << 8;
651 vm86_sysarch(struct thread *td, char *args)
654 struct i386_vm86_args ua;
655 struct vm86_kernel *vm86;
657 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
660 if (td->td_pcb->pcb_ext == 0)
661 if ((error = i386_extend_pcb(td)) != 0)
663 vm86 = &td->td_pcb->pcb_ext->ext_vm86;
667 struct vm86_init_args sa;
669 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
671 if (cpu_feature & CPUID_VME)
672 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
674 vm86->vm86_has_vme = 0;
675 vm86->vm86_inited = 1;
676 vm86->vm86_debug = sa.debug;
677 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
683 struct vm86_vme_args sa;
685 if ((cpu_feature & CPUID_VME) == 0)
688 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
691 load_cr4(rcr4() | CR4_VME);
693 load_cr4(rcr4() & ~CR4_VME);
699 struct vm86_vme_args sa;
701 sa.state = (rcr4() & CR4_VME ? 1 : 0);
702 error = copyout(&sa, ua.sub_args, sizeof(sa));
707 struct vm86_intcall_args sa;
709 if ((error = priv_check(td, PRIV_VM86_INTCALL)))
711 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
713 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
715 error = copyout(&sa, ua.sub_args, sizeof(sa));