2 * Copyright (c) 1997 Jonathan Lemon
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
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 1.3 2003/06/18 18:29:55 dillon Exp $
30 #include <sys/param.h>
31 #include <sys/systm.h>
34 #include <sys/malloc.h>
38 #include <vm/vm_map.h>
39 #include <vm/vm_page.h>
43 #include <machine/md_var.h>
44 #include <machine/pcb_ext.h> /* pcb.h included via sys/user.h */
45 #include <machine/psl.h>
46 #include <machine/specialreg.h>
47 #include <machine/sysarch.h>
49 extern int i386_extend_pcb __P((struct proc *));
51 extern struct pcb *vm86pcb;
53 extern int vm86_bioscall(struct vm86frame *);
54 extern void vm86_biosret(struct vm86frame *);
56 void vm86_prepcall(struct vm86frame);
72 #define OPERAND_SIZE_PREFIX 0x66
73 #define ADDRESS_SIZE_PREFIX 0x67
74 #define PUSH_MASK ~(PSL_VM | PSL_RF | PSL_I)
75 #define POP_MASK ~(PSL_VIP | PSL_VIF | PSL_VM | PSL_RF | PSL_IOPL)
77 static __inline caddr_t
78 MAKE_ADDR(u_short sel, u_short off)
80 return ((caddr_t)((sel << 4) + off));
84 GET_VEC(u_int vec, u_short *sel, u_short *off)
91 MAKE_VEC(u_short sel, u_short off)
93 return ((sel << 16) | off);
97 PUSH(u_short x, struct vm86frame *vmf)
100 susword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
104 PUSHL(u_int x, struct vm86frame *vmf)
107 suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
110 static __inline u_short
111 POP(struct vm86frame *vmf)
113 u_short x = fusword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
119 static __inline u_int
120 POPL(struct vm86frame *vmf)
122 u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
130 struct vm86frame *vmf;
132 struct vm86_kernel *vm86;
140 * pcb_ext contains the address of the extension area, or zero if
141 * the extension is not present. (This check should not be needed,
142 * as we can't enter vm86 mode until we set up an extension area)
144 if (curthread->td_pcb->pcb_ext == 0)
146 vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
148 if (vmf->vmf_eflags & PSL_T)
151 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
152 i_byte = fubyte(addr);
153 if (i_byte == ADDRESS_SIZE_PREFIX) {
154 i_byte = fubyte(++addr);
158 if (vm86->vm86_has_vme) {
160 case OPERAND_SIZE_PREFIX:
161 i_byte = fubyte(++addr);
165 if (vmf->vmf_eflags & PSL_VIF)
166 PUSHL((vmf->vmf_eflags & PUSH_MASK)
167 | PSL_IOPL | PSL_I, vmf);
169 PUSHL((vmf->vmf_eflags & PUSH_MASK)
171 vmf->vmf_ip += inc_ip;
175 temp_flags = POPL(vmf) & POP_MASK;
176 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
177 | temp_flags | PSL_VM | PSL_I;
178 vmf->vmf_ip += inc_ip;
179 if (temp_flags & PSL_I) {
180 vmf->vmf_eflags |= PSL_VIF;
181 if (vmf->vmf_eflags & PSL_VIP)
184 vmf->vmf_eflags &= ~PSL_VIF;
190 /* VME faults here if VIP is set, but does not set VIF. */
192 vmf->vmf_eflags |= PSL_VIF;
193 vmf->vmf_ip += inc_ip;
194 if ((vmf->vmf_eflags & PSL_VIP) == 0) {
195 uprintf("fatal sti\n");
200 /* VME if no redirection support */
204 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
206 temp_flags = POP(vmf) & POP_MASK;
207 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
208 | temp_flags | PSL_VM | PSL_I;
209 vmf->vmf_ip += inc_ip;
210 if (temp_flags & PSL_I) {
211 vmf->vmf_eflags |= PSL_VIF;
212 if (vmf->vmf_eflags & PSL_VIP)
215 vmf->vmf_eflags &= ~PSL_VIF;
219 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
221 vmf->vmf_ip = POP(vmf);
222 vmf->vmf_cs = POP(vmf);
223 temp_flags = POP(vmf) & POP_MASK;
224 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
225 | temp_flags | PSL_VM | PSL_I;
226 if (temp_flags & PSL_I) {
227 vmf->vmf_eflags |= PSL_VIF;
228 if (vmf->vmf_eflags & PSL_VIP)
231 vmf->vmf_eflags &= ~PSL_VIF;
240 case OPERAND_SIZE_PREFIX:
241 i_byte = fubyte(++addr);
245 if (vm86->vm86_eflags & PSL_VIF)
246 PUSHL((vmf->vmf_flags & PUSH_MASK)
247 | PSL_IOPL | PSL_I, vmf);
249 PUSHL((vmf->vmf_flags & PUSH_MASK)
251 vmf->vmf_ip += inc_ip;
255 temp_flags = POPL(vmf) & POP_MASK;
256 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
257 | temp_flags | PSL_VM | PSL_I;
258 vmf->vmf_ip += inc_ip;
259 if (temp_flags & PSL_I) {
260 vm86->vm86_eflags |= PSL_VIF;
261 if (vm86->vm86_eflags & PSL_VIP)
264 vm86->vm86_eflags &= ~PSL_VIF;
271 vm86->vm86_eflags &= ~PSL_VIF;
272 vmf->vmf_ip += inc_ip;
276 /* if there is a pending interrupt, go to the emulator */
277 vm86->vm86_eflags |= PSL_VIF;
278 vmf->vmf_ip += inc_ip;
279 if (vm86->vm86_eflags & PSL_VIP)
284 if (vm86->vm86_eflags & PSL_VIF)
285 PUSH((vmf->vmf_flags & PUSH_MASK)
286 | PSL_IOPL | PSL_I, vmf);
288 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
289 vmf->vmf_ip += inc_ip;
293 i_byte = fubyte(addr + 1);
294 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
296 if (vm86->vm86_eflags & PSL_VIF)
297 PUSH((vmf->vmf_flags & PUSH_MASK)
298 | PSL_IOPL | PSL_I, vmf);
300 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
301 PUSH(vmf->vmf_cs, vmf);
302 PUSH(vmf->vmf_ip + inc_ip + 1, vmf); /* increment IP */
303 GET_VEC(fuword((caddr_t)(i_byte * 4)),
304 &vmf->vmf_cs, &vmf->vmf_ip);
305 vmf->vmf_flags &= ~PSL_T;
306 vm86->vm86_eflags &= ~PSL_VIF;
310 vmf->vmf_ip = POP(vmf);
311 vmf->vmf_cs = POP(vmf);
312 temp_flags = POP(vmf) & POP_MASK;
313 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
314 | temp_flags | PSL_VM | PSL_I;
315 if (temp_flags & PSL_I) {
316 vm86->vm86_eflags |= PSL_VIF;
317 if (vm86->vm86_eflags & PSL_VIP)
320 vm86->vm86_eflags &= ~PSL_VIF;
325 temp_flags = POP(vmf) & POP_MASK;
326 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
327 | temp_flags | PSL_VM | PSL_I;
328 vmf->vmf_ip += inc_ip;
329 if (temp_flags & PSL_I) {
330 vm86->vm86_eflags |= PSL_VIF;
331 if (vm86->vm86_eflags & PSL_VIP)
334 vm86->vm86_eflags &= ~PSL_VIF;
341 #define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE)
342 #define INTMAP_SIZE 32
343 #define IOMAP_SIZE ctob(IOPAGES)
345 (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
346 INTMAP_SIZE + IOMAP_SIZE + 1)
349 pt_entry_t vml_pgtbl[PGTABLE_SIZE];
351 struct pcb_ext vml_ext;
352 char vml_intmap[INTMAP_SIZE];
353 char vml_iomap[IOMAP_SIZE];
354 char vml_iomap_trailer;
358 vm86_initialize(void)
362 struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
365 struct soft_segment_descriptor ssd = {
366 0, /* segment base address (overwritten) */
367 0, /* length (overwritten) */
368 SDT_SYS386TSS, /* segment type */
369 0, /* priority level */
370 1, /* descriptor present */
372 0, /* default 16 size */
377 * this should be a compile time error, but cpp doesn't grok sizeof().
379 if (sizeof(struct vm86_layout) > ctob(3))
380 panic("struct vm86_layout exceeds space allocated in locore.s");
383 * Below is the memory layout that we use for the vm86 region.
391 * +--------+ +--------+ <--------- vm86paddr
392 * | | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
394 * | | | PCB | size: ~240 bytes
395 * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
401 * +--------+ | bitmap |
408 * A rudimentary PCB must be installed, in order to get to the
409 * PCB extension area. We use the PCB area as a scratchpad for
410 * data storage, the layout of which is shown below.
412 * pcb_esi = new PTD entry 0
413 * pcb_ebp = pointer to frame on vm86 stack
414 * pcb_esp = stack frame pointer at time of switch
415 * pcb_ebx = va of vm86 page table
416 * pcb_eip = argument pointer to initial call
417 * pcb_spare[0] = saved TSS descriptor, word 0
418 * pcb_space[1] = saved TSS descriptor, word 1
420 #define new_ptd pcb_esi
421 #define vm86_frame pcb_ebp
422 #define pgtable_va pcb_ebx
427 bzero(pcb, sizeof(struct pcb));
428 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
429 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
430 pcb->pgtable_va = vm86paddr;
433 bzero(ext, sizeof(struct pcb_ext));
434 ext->ext_tss.tss_esp0 = vm86paddr;
435 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
436 ext->ext_tss.tss_ioopt =
437 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
438 ext->ext_iomap = vml->vml_iomap;
439 ext->ext_vm86.vm86_intmap = vml->vml_intmap;
441 if (cpu_feature & CPUID_VME)
442 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
444 addr = (u_int *)ext->ext_vm86.vm86_intmap;
445 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
447 vml->vml_iomap_trailer = 0xff;
449 ssd.ssd_base = (u_int)&ext->ext_tss;
450 ssd.ssd_limit = TSS_SIZE - 1;
451 ssdtosd(&ssd, &ext->ext_tssd);
457 * use whatever is leftover of the vm86 page layout as a
458 * message buffer so we can capture early output.
460 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
461 ctob(3) - sizeof(struct vm86_layout));
466 vm86_getpage(struct vm86context *vmc, int pagenum)
470 for (i = 0; i < vmc->npages; i++)
471 if (vmc->pmap[i].pte_num == pagenum)
472 return (vmc->pmap[i].kva);
477 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
481 for (i = 0; i < vmc->npages; i++)
482 if (vmc->pmap[i].pte_num == pagenum)
485 if (vmc->npages == VM86_PMAPSIZE)
486 goto bad; /* XXX grow map? */
489 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
494 vmc->pmap[i].flags = flags;
495 vmc->pmap[i].kva = kva;
496 vmc->pmap[i].pte_num = pagenum;
499 panic("vm86_addpage: not enough room, or overlap");
503 vm86_initflags(struct vm86frame *vmf)
505 int eflags = vmf->vmf_eflags;
506 struct vm86_kernel *vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
508 if (vm86->vm86_has_vme) {
509 eflags = (vmf->vmf_eflags & ~VME_USERCHANGE) |
510 (eflags & VME_USERCHANGE) | PSL_VM;
512 vm86->vm86_eflags = eflags; /* save VIF, VIP */
513 eflags = (vmf->vmf_eflags & ~VM_USERCHANGE) |
514 (eflags & VM_USERCHANGE) | PSL_VM;
516 vmf->vmf_eflags = eflags | PSL_VM;
520 * called from vm86_bioscall, while in vm86 address space, to finalize setup.
523 vm86_prepcall(struct vm86frame vmf)
525 uintptr_t addr[] = { 0xA00, 0x1000 }; /* code, stack */
527 CLI, INTn, 0x00, STI, HLT
530 if ((vmf.vmf_trapno & PAGE_MASK) <= 0xff) {
531 /* interrupt call requested */
532 intcall[2] = (u_char)(vmf.vmf_trapno & 0xff);
533 memcpy((void *)addr[0], (void *)intcall, sizeof(intcall));
534 vmf.vmf_ip = addr[0];
537 vmf.vmf_sp = addr[1] - 2; /* keep aligned */
538 vmf.kernel_fs = vmf.kernel_es = vmf.kernel_ds = 0;
540 vmf.vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
541 vm86_initflags(&vmf);
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)
569 if (intnum < 0 || intnum > 0xff)
572 vmf->vmf_trapno = intnum;
573 return (vm86_bioscall(vmf));
577 * struct vm86context contains the page table to use when making
578 * vm86 calls. If intnum is a valid interrupt number (0-255), then
579 * the "interrupt trampoline" will be used, otherwise we use the
580 * caller's cs:ip routine.
583 vm86_datacall(intnum, vmf, vmc)
585 struct vm86frame *vmf;
586 struct vm86context *vmc;
588 pt_entry_t pte = (pt_entry_t)vm86paddr;
590 int i, entry, retval;
592 for (i = 0; i < vmc->npages; i++) {
593 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
594 entry = vmc->pmap[i].pte_num;
595 vmc->pmap[i].old_pte = pte[entry];
596 pte[entry] = page | PG_V | PG_RW | PG_U;
599 vmf->vmf_trapno = intnum;
600 retval = vm86_bioscall(vmf);
602 for (i = 0; i < vmc->npages; i++) {
603 entry = vmc->pmap[i].pte_num;
604 pte[entry] = vmc->pmap[i].old_pte;
611 vm86_getaddr(vmc, sel, off)
612 struct vm86context *vmc;
619 addr = (vm_offset_t)MAKE_ADDR(sel, off);
620 page = addr >> PAGE_SHIFT;
621 for (i = 0; i < vmc->npages; i++)
622 if (page == vmc->pmap[i].pte_num)
623 return (vmc->pmap[i].kva + (addr & PAGE_MASK));
628 vm86_getptr(vmc, kva, sel, off)
629 struct vm86context *vmc;
636 for (i = 0; i < vmc->npages; i++)
637 if (kva >= vmc->pmap[i].kva &&
638 kva < vmc->pmap[i].kva + PAGE_SIZE) {
639 *off = kva - vmc->pmap[i].kva;
640 *sel = vmc->pmap[i].pte_num << 8;
644 panic("vm86_getptr: address not found");
648 vm86_sysarch(p, args)
653 struct i386_vm86_args ua;
654 struct vm86_kernel *vm86;
656 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
659 if (p->p_thread->td_pcb->pcb_ext == 0)
660 if ((error = i386_extend_pcb(p)) != 0)
662 vm86 = &p->p_thread->td_pcb->pcb_ext->ext_vm86;
666 struct vm86_init_args sa;
668 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
670 if (cpu_feature & CPUID_VME)
671 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
673 vm86->vm86_has_vme = 0;
674 vm86->vm86_inited = 1;
675 vm86->vm86_debug = sa.debug;
676 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
682 struct vm86_vme_args sa;
684 if ((cpu_feature & CPUID_VME) == 0)
687 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
690 load_cr4(rcr4() | CR4_VME);
692 load_cr4(rcr4() & ~CR4_VME);
698 struct vm86_vme_args sa;
700 sa.state = (rcr4() & CR4_VME ? 1 : 0);
701 error = copyout(&sa, ua.sub_args, sizeof(sa));
706 struct vm86_intcall_args sa;
708 if ((error = suser(p)))
710 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
712 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
714 error = copyout(&sa, ua.sub_args, sizeof(sa));