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 1.7 2003/07/08 06:27:26 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>
42 #include <sys/thread2.h>
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>
50 extern int i386_extend_pcb __P((struct proc *));
52 extern struct pcb *vm86pcb;
54 extern int vm86_bioscall(struct vm86frame *);
55 extern void vm86_biosret(struct vm86frame *);
57 void vm86_prepcall(struct vm86frame);
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)
78 static __inline caddr_t
79 MAKE_ADDR(u_short sel, u_short off)
81 return ((caddr_t)((sel << 4) + off));
85 GET_VEC(u_int vec, u_short *sel, u_short *off)
92 MAKE_VEC(u_short sel, u_short off)
94 return ((sel << 16) | off);
98 PUSH(u_short x, struct vm86frame *vmf)
101 susword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
105 PUSHL(u_int x, struct vm86frame *vmf)
108 suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
111 static __inline u_short
112 POP(struct vm86frame *vmf)
114 u_short x = fusword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
120 static __inline u_int
121 POPL(struct vm86frame *vmf)
123 u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
131 struct vm86frame *vmf;
133 struct vm86_kernel *vm86;
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)
145 if (curthread->td_pcb->pcb_ext == 0)
147 vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
149 if (vmf->vmf_eflags & PSL_T)
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);
159 if (vm86->vm86_has_vme) {
161 case OPERAND_SIZE_PREFIX:
162 i_byte = fubyte(++addr);
166 if (vmf->vmf_eflags & PSL_VIF)
167 PUSHL((vmf->vmf_eflags & PUSH_MASK)
168 | PSL_IOPL | PSL_I, vmf);
170 PUSHL((vmf->vmf_eflags & PUSH_MASK)
172 vmf->vmf_ip += inc_ip;
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)
185 vmf->vmf_eflags &= ~PSL_VIF;
191 /* VME faults here if VIP is set, but does not set VIF. */
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");
201 /* VME if no redirection support */
205 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
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)
216 vmf->vmf_eflags &= ~PSL_VIF;
220 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
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)
232 vmf->vmf_eflags &= ~PSL_VIF;
241 case OPERAND_SIZE_PREFIX:
242 i_byte = fubyte(++addr);
246 if (vm86->vm86_eflags & PSL_VIF)
247 PUSHL((vmf->vmf_flags & PUSH_MASK)
248 | PSL_IOPL | PSL_I, vmf);
250 PUSHL((vmf->vmf_flags & PUSH_MASK)
252 vmf->vmf_ip += inc_ip;
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)
265 vm86->vm86_eflags &= ~PSL_VIF;
272 vm86->vm86_eflags &= ~PSL_VIF;
273 vmf->vmf_ip += inc_ip;
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)
285 if (vm86->vm86_eflags & PSL_VIF)
286 PUSH((vmf->vmf_flags & PUSH_MASK)
287 | PSL_IOPL | PSL_I, vmf);
289 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
290 vmf->vmf_ip += inc_ip;
294 i_byte = fubyte(addr + 1);
295 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
297 if (vm86->vm86_eflags & PSL_VIF)
298 PUSH((vmf->vmf_flags & PUSH_MASK)
299 | PSL_IOPL | PSL_I, vmf);
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;
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)
321 vm86->vm86_eflags &= ~PSL_VIF;
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)
335 vm86->vm86_eflags &= ~PSL_VIF;
342 #define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE)
343 #define INTMAP_SIZE 32
344 #define IOMAP_SIZE ctob(IOPAGES)
346 (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
347 INTMAP_SIZE + IOMAP_SIZE + 1)
350 pt_entry_t vml_pgtbl[PGTABLE_SIZE];
352 struct pcb_ext vml_ext;
353 char vml_intmap[INTMAP_SIZE];
354 char vml_iomap[IOMAP_SIZE];
355 char vml_iomap_trailer;
359 vm86_initialize(void)
363 struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
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 */
373 0, /* default 16 size */
378 * this should be a compile time error, but cpp doesn't grok sizeof().
380 if (sizeof(struct vm86_layout) > ctob(3))
381 panic("struct vm86_layout exceeds space allocated in locore.s");
384 * Below is the memory layout that we use for the vm86 region.
392 * +--------+ +--------+ <--------- vm86paddr
393 * | | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
395 * | | | PCB | size: ~240 bytes
396 * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
402 * +--------+ | bitmap |
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.
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
421 #define new_ptd pcb_esi
422 #define vm86_frame pcb_ebp
423 #define pgtable_va pcb_ebx
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;
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;
442 if (cpu_feature & CPUID_VME)
443 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
445 addr = (u_int *)ext->ext_vm86.vm86_intmap;
446 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
448 vml->vml_iomap_trailer = 0xff;
450 ssd.ssd_base = (u_int)&ext->ext_tss;
451 ssd.ssd_limit = TSS_SIZE - 1;
452 ssdtosd(&ssd, &ext->ext_tssd);
458 * use whatever is leftover of the vm86 page layout as a
459 * message buffer so we can capture early output.
461 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
462 ctob(3) - sizeof(struct vm86_layout));
467 vm86_getpage(struct vm86context *vmc, int pagenum)
471 for (i = 0; i < vmc->npages; i++)
472 if (vmc->pmap[i].pte_num == pagenum)
473 return (vmc->pmap[i].kva);
478 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
482 for (i = 0; i < vmc->npages; i++)
483 if (vmc->pmap[i].pte_num == pagenum)
486 if (vmc->npages == VM86_PMAPSIZE)
487 goto bad; /* XXX grow map? */
490 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
495 vmc->pmap[i].flags = flags;
496 vmc->pmap[i].kva = kva;
497 vmc->pmap[i].pte_num = pagenum;
500 panic("vm86_addpage: not enough room, or overlap");
504 vm86_initflags(struct vm86frame *vmf)
506 int eflags = vmf->vmf_eflags;
507 struct vm86_kernel *vm86 = &curthread->td_pcb->pcb_ext->ext_vm86;
509 if (vm86->vm86_has_vme) {
510 eflags = (vmf->vmf_eflags & ~VME_USERCHANGE) |
511 (eflags & VME_USERCHANGE) | PSL_VM;
513 vm86->vm86_eflags = eflags; /* save VIF, VIP */
514 eflags = (vmf->vmf_eflags & ~VM_USERCHANGE) |
515 (eflags & VM_USERCHANGE) | PSL_VM;
517 vmf->vmf_eflags = eflags | PSL_VM;
521 * called from vm86_bioscall, while in vm86 address space, to finalize setup.
524 vm86_prepcall(struct vm86frame vmf)
526 uintptr_t addr[] = { 0xA00, 0x1000 }; /* code, stack */
528 CLI, INTn, 0x00, STI, HLT
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];
538 vmf.vmf_sp = addr[1] - 2; /* keep aligned */
539 vmf.kernel_fs = vmf.kernel_es = vmf.kernel_ds = 0;
541 vmf.vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
542 vm86_initflags(&vmf);
546 * vm86 trap handler; determines whether routine succeeded or not.
547 * Called while in vm86 space, returns to calling process.
549 * A MP lock ref is held on entry from trap() and must be released prior
550 * to returning to the VM86 call.
553 vm86_trap(struct vm86frame *vmf)
557 /* "should not happen" */
558 if ((vmf->vmf_eflags & PSL_VM) == 0)
559 panic("vm86_trap called, but not in vm86 mode");
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;
565 vmf->vmf_trapno = vmf->vmf_trapno << 16;
572 vm86_intcall(int intnum, struct vm86frame *vmf)
576 if (intnum < 0 || intnum > 0xff)
580 ASSERT_MP_LOCK_HELD();
582 vmf->vmf_trapno = intnum;
583 error = vm86_bioscall(vmf);
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.
595 vm86_datacall(intnum, vmf, vmc)
597 struct vm86frame *vmf;
598 struct vm86context *vmc;
600 pt_entry_t pte = (pt_entry_t)vm86paddr;
602 int i, entry, retval;
605 ASSERT_MP_LOCK_HELD();
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;
614 vmf->vmf_trapno = intnum;
615 retval = vm86_bioscall(vmf);
617 for (i = 0; i < vmc->npages; i++) {
618 entry = vmc->pmap[i].pte_num;
619 pte[entry] = vmc->pmap[i].old_pte;
626 vm86_getaddr(vmc, sel, off)
627 struct vm86context *vmc;
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));
643 vm86_getptr(vmc, kva, sel, off)
644 struct vm86context *vmc;
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;
659 panic("vm86_getptr: address not found");
663 vm86_sysarch(struct proc *p, char *args)
666 struct i386_vm86_args ua;
667 struct vm86_kernel *vm86;
669 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
672 if (p->p_thread->td_pcb->pcb_ext == 0)
673 if ((error = i386_extend_pcb(p)) != 0)
675 vm86 = &p->p_thread->td_pcb->pcb_ext->ext_vm86;
679 struct vm86_init_args sa;
681 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
683 if (cpu_feature & CPUID_VME)
684 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
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);
695 struct vm86_vme_args sa;
697 if ((cpu_feature & CPUID_VME) == 0)
700 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
703 load_cr4(rcr4() | CR4_VME);
705 load_cr4(rcr4() & ~CR4_VME);
711 struct vm86_vme_args sa;
713 sa.state = (rcr4() & CR4_VME ? 1 : 0);
714 error = copyout(&sa, ua.sub_args, sizeof(sa));
719 struct vm86_intcall_args sa;
721 if ((error = suser_cred(p->p_ucred, 0)))
723 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
725 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
727 error = copyout(&sa, ua.sub_args, sizeof(sa));