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
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/mutex.h>
40 #include <vm/vm_map.h>
41 #include <vm/vm_page.h>
43 #include <machine/md_var.h>
44 #include <machine/pcb.h>
45 #include <machine/pcb_ext.h>
46 #include <machine/psl.h>
47 #include <machine/specialreg.h>
48 #include <machine/sysarch.h>
51 extern struct pcb *vm86pcb;
53 static struct mtx vm86_lock;
55 extern int vm86_bioscall(struct vm86frame *);
56 extern void vm86_biosret(struct vm86frame *);
58 void vm86_prepcall(struct vm86frame *);
74 #define OPERAND_SIZE_PREFIX 0x66
75 #define ADDRESS_SIZE_PREFIX 0x67
76 #define PUSH_MASK ~(PSL_VM | PSL_RF | PSL_I)
77 #define POP_MASK ~(PSL_VIP | PSL_VIF | PSL_VM | PSL_RF | PSL_IOPL)
79 static __inline caddr_t
80 MAKE_ADDR(u_short sel, u_short off)
82 return ((caddr_t)((sel << 4) + off));
86 GET_VEC(u_int vec, u_short *sel, u_short *off)
93 MAKE_VEC(u_short sel, u_short off)
95 return ((sel << 16) | off);
99 PUSH(u_short x, struct vm86frame *vmf)
102 suword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
106 PUSHL(u_int x, struct vm86frame *vmf)
109 suword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp), x);
112 static __inline u_short
113 POP(struct vm86frame *vmf)
115 u_short x = fuword16(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
121 static __inline u_int
122 POPL(struct vm86frame *vmf)
124 u_int x = fuword(MAKE_ADDR(vmf->vmf_ss, vmf->vmf_sp));
131 vm86_emulate(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 (curpcb->pcb_ext == 0)
147 vm86 = &curpcb->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_T, 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_T, 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_vm86[0] = saved TSS descriptor, word 0
419 * pcb_vm86[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 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF);
430 bzero(pcb, sizeof(struct pcb));
431 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
432 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
433 pcb->pgtable_va = vm86paddr;
434 pcb->pcb_flags = PCB_VM86CALL;
437 bzero(ext, sizeof(struct pcb_ext));
438 ext->ext_tss.tss_esp0 = vm86paddr;
439 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
440 ext->ext_tss.tss_ioopt =
441 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
442 ext->ext_iomap = vml->vml_iomap;
443 ext->ext_vm86.vm86_intmap = vml->vml_intmap;
445 if (cpu_feature & CPUID_VME)
446 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
448 addr = (u_int *)ext->ext_vm86.vm86_intmap;
449 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
451 vml->vml_iomap_trailer = 0xff;
453 ssd.ssd_base = (u_int)&ext->ext_tss;
454 ssd.ssd_limit = TSS_SIZE - 1;
455 ssdtosd(&ssd, &ext->ext_tssd);
461 * use whatever is leftover of the vm86 page layout as a
462 * message buffer so we can capture early output.
464 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
465 ctob(3) - sizeof(struct vm86_layout));
470 vm86_getpage(struct vm86context *vmc, int pagenum)
474 for (i = 0; i < vmc->npages; i++)
475 if (vmc->pmap[i].pte_num == pagenum)
476 return (vmc->pmap[i].kva);
481 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
485 for (i = 0; i < vmc->npages; i++)
486 if (vmc->pmap[i].pte_num == pagenum)
489 if (vmc->npages == VM86_PMAPSIZE)
490 goto full; /* XXX grow map? */
493 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
498 vmc->pmap[i].flags = flags;
499 vmc->pmap[i].kva = kva;
500 vmc->pmap[i].pte_num = pagenum;
503 panic("vm86_addpage: overlap");
505 panic("vm86_addpage: not enough room");
509 * called from vm86_bioscall, while in vm86 address space, to finalize setup.
512 vm86_prepcall(struct vm86frame *vmf)
514 struct vm86_kernel *vm86;
518 code = (void *)0xa00;
519 stack = (void *)(0x1000 - 2); /* keep aligned */
520 if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) {
521 /* interrupt call requested */
523 code[1] = vmf->vmf_trapno & 0xff;
525 vmf->vmf_ip = (uintptr_t)code;
530 stack[0] = MAKE_VEC(0, (uintptr_t)code);
532 vmf->vmf_sp = (uintptr_t)stack;
534 vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = 0;
535 vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
537 vm86 = &curpcb->pcb_ext->ext_vm86;
538 if (!vm86->vm86_has_vme)
539 vm86->vm86_eflags = vmf->vmf_eflags; /* save VIF, VIP */
543 * vm86 trap handler; determines whether routine succeeded or not.
544 * Called while in vm86 space, returns to calling process.
547 vm86_trap(struct vm86frame *vmf)
551 /* "should not happen" */
552 if ((vmf->vmf_eflags & PSL_VM) == 0)
553 panic("vm86_trap called, but not in vm86 mode");
555 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
556 if (*(u_char *)addr == HLT)
557 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
559 vmf->vmf_trapno = vmf->vmf_trapno << 16;
565 vm86_intcall(int intnum, struct vm86frame *vmf)
569 if (intnum < 0 || intnum > 0xff)
572 vmf->vmf_trapno = intnum;
573 mtx_lock(&vm86_lock);
575 retval = vm86_bioscall(vmf);
577 mtx_unlock(&vm86_lock);
582 * struct vm86context contains the page table to use when making
583 * vm86 calls. If intnum is a valid interrupt number (0-255), then
584 * the "interrupt trampoline" will be used, otherwise we use the
585 * caller's cs:ip routine.
588 vm86_datacall(int intnum, struct vm86frame *vmf, struct vm86context *vmc)
590 pt_entry_t *pte = (pt_entry_t *)vm86paddr;
592 int i, entry, retval;
594 mtx_lock(&vm86_lock);
595 for (i = 0; i < vmc->npages; i++) {
596 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
597 entry = vmc->pmap[i].pte_num;
598 vmc->pmap[i].old_pte = pte[entry];
599 pte[entry] = page | PG_V | PG_RW | PG_U;
600 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
603 vmf->vmf_trapno = intnum;
605 retval = vm86_bioscall(vmf);
608 for (i = 0; i < vmc->npages; i++) {
609 entry = vmc->pmap[i].pte_num;
610 pte[entry] = vmc->pmap[i].old_pte;
611 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
613 mtx_unlock(&vm86_lock);
619 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off)
624 addr = (vm_offset_t)MAKE_ADDR(sel, off);
625 page = addr >> PAGE_SHIFT;
626 for (i = 0; i < vmc->npages; i++)
627 if (page == vmc->pmap[i].pte_num)
628 return (vmc->pmap[i].kva + (addr & PAGE_MASK));
633 vm86_getptr(struct vm86context *vmc, vm_offset_t kva, u_short *sel,
638 for (i = 0; i < vmc->npages; i++)
639 if (kva >= vmc->pmap[i].kva &&
640 kva < vmc->pmap[i].kva + PAGE_SIZE) {
641 *off = kva - vmc->pmap[i].kva;
642 *sel = vmc->pmap[i].pte_num << 8;
649 vm86_sysarch(struct thread *td, char *args)
652 struct i386_vm86_args ua;
653 struct vm86_kernel *vm86;
655 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
658 if (td->td_pcb->pcb_ext == 0)
659 if ((error = i386_extend_pcb(td)) != 0)
661 vm86 = &td->td_pcb->pcb_ext->ext_vm86;
665 struct vm86_init_args sa;
667 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
669 if (cpu_feature & CPUID_VME)
670 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
672 vm86->vm86_has_vme = 0;
673 vm86->vm86_inited = 1;
674 vm86->vm86_debug = sa.debug;
675 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
681 struct vm86_vme_args sa;
683 if ((cpu_feature & CPUID_VME) == 0)
686 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
689 load_cr4(rcr4() | CR4_VME);
691 load_cr4(rcr4() & ~CR4_VME);
697 struct vm86_vme_args sa;
699 sa.state = (rcr4() & CR4_VME ? 1 : 0);
700 error = copyout(&sa, ua.sub_args, sizeof(sa));
705 struct vm86_intcall_args sa;
707 if ((error = priv_check(td, PRIV_VM86_INTCALL)))
709 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
711 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
713 error = copyout(&sa, ua.sub_args, sizeof(sa));