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));
132 struct vm86frame *vmf;
134 struct vm86_kernel *vm86;
142 * pcb_ext contains the address of the extension area, or zero if
143 * the extension is not present. (This check should not be needed,
144 * as we can't enter vm86 mode until we set up an extension area)
146 if (curpcb->pcb_ext == 0)
148 vm86 = &curpcb->pcb_ext->ext_vm86;
150 if (vmf->vmf_eflags & PSL_T)
153 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
154 i_byte = fubyte(addr);
155 if (i_byte == ADDRESS_SIZE_PREFIX) {
156 i_byte = fubyte(++addr);
160 if (vm86->vm86_has_vme) {
162 case OPERAND_SIZE_PREFIX:
163 i_byte = fubyte(++addr);
167 if (vmf->vmf_eflags & PSL_VIF)
168 PUSHL((vmf->vmf_eflags & PUSH_MASK)
169 | PSL_IOPL | PSL_I, vmf);
171 PUSHL((vmf->vmf_eflags & PUSH_MASK)
173 vmf->vmf_ip += inc_ip;
177 temp_flags = POPL(vmf) & POP_MASK;
178 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
179 | temp_flags | PSL_VM | PSL_I;
180 vmf->vmf_ip += inc_ip;
181 if (temp_flags & PSL_I) {
182 vmf->vmf_eflags |= PSL_VIF;
183 if (vmf->vmf_eflags & PSL_VIP)
186 vmf->vmf_eflags &= ~PSL_VIF;
192 /* VME faults here if VIP is set, but does not set VIF. */
194 vmf->vmf_eflags |= PSL_VIF;
195 vmf->vmf_ip += inc_ip;
196 if ((vmf->vmf_eflags & PSL_VIP) == 0) {
197 uprintf("fatal sti\n");
202 /* VME if no redirection support */
206 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
208 temp_flags = POP(vmf) & POP_MASK;
209 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
210 | temp_flags | PSL_VM | PSL_I;
211 vmf->vmf_ip += inc_ip;
212 if (temp_flags & PSL_I) {
213 vmf->vmf_eflags |= PSL_VIF;
214 if (vmf->vmf_eflags & PSL_VIP)
217 vmf->vmf_eflags &= ~PSL_VIF;
221 /* VME if trying to set PSL_TF, or PSL_I when VIP is set */
223 vmf->vmf_ip = POP(vmf);
224 vmf->vmf_cs = POP(vmf);
225 temp_flags = POP(vmf) & POP_MASK;
226 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
227 | temp_flags | PSL_VM | PSL_I;
228 if (temp_flags & PSL_I) {
229 vmf->vmf_eflags |= PSL_VIF;
230 if (vmf->vmf_eflags & PSL_VIP)
233 vmf->vmf_eflags &= ~PSL_VIF;
242 case OPERAND_SIZE_PREFIX:
243 i_byte = fubyte(++addr);
247 if (vm86->vm86_eflags & PSL_VIF)
248 PUSHL((vmf->vmf_flags & PUSH_MASK)
249 | PSL_IOPL | PSL_I, vmf);
251 PUSHL((vmf->vmf_flags & PUSH_MASK)
253 vmf->vmf_ip += inc_ip;
257 temp_flags = POPL(vmf) & POP_MASK;
258 vmf->vmf_eflags = (vmf->vmf_eflags & ~POP_MASK)
259 | temp_flags | PSL_VM | PSL_I;
260 vmf->vmf_ip += inc_ip;
261 if (temp_flags & PSL_I) {
262 vm86->vm86_eflags |= PSL_VIF;
263 if (vm86->vm86_eflags & PSL_VIP)
266 vm86->vm86_eflags &= ~PSL_VIF;
273 vm86->vm86_eflags &= ~PSL_VIF;
274 vmf->vmf_ip += inc_ip;
278 /* if there is a pending interrupt, go to the emulator */
279 vm86->vm86_eflags |= PSL_VIF;
280 vmf->vmf_ip += inc_ip;
281 if (vm86->vm86_eflags & PSL_VIP)
286 if (vm86->vm86_eflags & PSL_VIF)
287 PUSH((vmf->vmf_flags & PUSH_MASK)
288 | PSL_IOPL | PSL_I, vmf);
290 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
291 vmf->vmf_ip += inc_ip;
295 i_byte = fubyte(addr + 1);
296 if ((vm86->vm86_intmap[i_byte >> 3] & (1 << (i_byte & 7))) != 0)
298 if (vm86->vm86_eflags & PSL_VIF)
299 PUSH((vmf->vmf_flags & PUSH_MASK)
300 | PSL_IOPL | PSL_I, vmf);
302 PUSH((vmf->vmf_flags & PUSH_MASK) | PSL_IOPL, vmf);
303 PUSH(vmf->vmf_cs, vmf);
304 PUSH(vmf->vmf_ip + inc_ip + 1, vmf); /* increment IP */
305 GET_VEC(fuword((caddr_t)(i_byte * 4)),
306 &vmf->vmf_cs, &vmf->vmf_ip);
307 vmf->vmf_flags &= ~PSL_T;
308 vm86->vm86_eflags &= ~PSL_VIF;
312 vmf->vmf_ip = POP(vmf);
313 vmf->vmf_cs = POP(vmf);
314 temp_flags = POP(vmf) & POP_MASK;
315 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
316 | temp_flags | PSL_VM | PSL_I;
317 if (temp_flags & PSL_I) {
318 vm86->vm86_eflags |= PSL_VIF;
319 if (vm86->vm86_eflags & PSL_VIP)
322 vm86->vm86_eflags &= ~PSL_VIF;
327 temp_flags = POP(vmf) & POP_MASK;
328 vmf->vmf_flags = (vmf->vmf_flags & ~POP_MASK)
329 | temp_flags | PSL_VM | PSL_I;
330 vmf->vmf_ip += inc_ip;
331 if (temp_flags & PSL_I) {
332 vm86->vm86_eflags |= PSL_VIF;
333 if (vm86->vm86_eflags & PSL_VIP)
336 vm86->vm86_eflags &= ~PSL_VIF;
343 #define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE)
344 #define INTMAP_SIZE 32
345 #define IOMAP_SIZE ctob(IOPAGES)
347 (sizeof(struct pcb_ext) - sizeof(struct segment_descriptor) + \
348 INTMAP_SIZE + IOMAP_SIZE + 1)
351 pt_entry_t vml_pgtbl[PGTABLE_SIZE];
353 struct pcb_ext vml_ext;
354 char vml_intmap[INTMAP_SIZE];
355 char vml_iomap[IOMAP_SIZE];
356 char vml_iomap_trailer;
360 vm86_initialize(void)
364 struct vm86_layout *vml = (struct vm86_layout *)vm86paddr;
367 struct soft_segment_descriptor ssd = {
368 0, /* segment base address (overwritten) */
369 0, /* length (overwritten) */
370 SDT_SYS386TSS, /* segment type */
371 0, /* priority level */
372 1, /* descriptor present */
374 0, /* default 16 size */
379 * this should be a compile time error, but cpp doesn't grok sizeof().
381 if (sizeof(struct vm86_layout) > ctob(3))
382 panic("struct vm86_layout exceeds space allocated in locore.s");
385 * Below is the memory layout that we use for the vm86 region.
393 * +--------+ +--------+ <--------- vm86paddr
394 * | | |Page Tbl| 1M + 64K = 272 entries = 1088 bytes
396 * | | | PCB | size: ~240 bytes
397 * | page 1 | |PCB Ext | size: ~140 bytes (includes TSS)
403 * +--------+ | bitmap |
410 * A rudimentary PCB must be installed, in order to get to the
411 * PCB extension area. We use the PCB area as a scratchpad for
412 * data storage, the layout of which is shown below.
414 * pcb_esi = new PTD entry 0
415 * pcb_ebp = pointer to frame on vm86 stack
416 * pcb_esp = stack frame pointer at time of switch
417 * pcb_ebx = va of vm86 page table
418 * pcb_eip = argument pointer to initial call
419 * pcb_spare[0] = saved TSS descriptor, word 0
420 * pcb_space[1] = saved TSS descriptor, word 1
422 #define new_ptd pcb_esi
423 #define vm86_frame pcb_ebp
424 #define pgtable_va pcb_ebx
429 mtx_init(&vm86_lock, "vm86 lock", NULL, MTX_DEF);
431 bzero(pcb, sizeof(struct pcb));
432 pcb->new_ptd = vm86pa | PG_V | PG_RW | PG_U;
433 pcb->vm86_frame = vm86paddr - sizeof(struct vm86frame);
434 pcb->pgtable_va = vm86paddr;
435 pcb->pcb_flags = PCB_VM86CALL;
438 bzero(ext, sizeof(struct pcb_ext));
439 ext->ext_tss.tss_esp0 = vm86paddr;
440 ext->ext_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
441 ext->ext_tss.tss_ioopt =
442 ((u_int)vml->vml_iomap - (u_int)&ext->ext_tss) << 16;
443 ext->ext_iomap = vml->vml_iomap;
444 ext->ext_vm86.vm86_intmap = vml->vml_intmap;
446 if (cpu_feature & CPUID_VME)
447 ext->ext_vm86.vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
449 addr = (u_int *)ext->ext_vm86.vm86_intmap;
450 for (i = 0; i < (INTMAP_SIZE + IOMAP_SIZE) / sizeof(u_int); i++)
452 vml->vml_iomap_trailer = 0xff;
454 ssd.ssd_base = (u_int)&ext->ext_tss;
455 ssd.ssd_limit = TSS_SIZE - 1;
456 ssdtosd(&ssd, &ext->ext_tssd);
462 * use whatever is leftover of the vm86 page layout as a
463 * message buffer so we can capture early output.
465 msgbufinit((vm_offset_t)vm86paddr + sizeof(struct vm86_layout),
466 ctob(3) - sizeof(struct vm86_layout));
471 vm86_getpage(struct vm86context *vmc, int pagenum)
475 for (i = 0; i < vmc->npages; i++)
476 if (vmc->pmap[i].pte_num == pagenum)
477 return (vmc->pmap[i].kva);
482 vm86_addpage(struct vm86context *vmc, int pagenum, vm_offset_t kva)
486 for (i = 0; i < vmc->npages; i++)
487 if (vmc->pmap[i].pte_num == pagenum)
490 if (vmc->npages == VM86_PMAPSIZE)
491 goto full; /* XXX grow map? */
494 kva = (vm_offset_t)malloc(PAGE_SIZE, M_TEMP, M_WAITOK);
499 vmc->pmap[i].flags = flags;
500 vmc->pmap[i].kva = kva;
501 vmc->pmap[i].pte_num = pagenum;
504 panic("vm86_addpage: overlap");
506 panic("vm86_addpage: not enough room");
510 * called from vm86_bioscall, while in vm86 address space, to finalize setup.
513 vm86_prepcall(struct vm86frame *vmf)
515 struct vm86_kernel *vm86;
519 code = (void *)0xa00;
520 stack = (void *)(0x1000 - 2); /* keep aligned */
521 if ((vmf->vmf_trapno & PAGE_MASK) <= 0xff) {
522 /* interrupt call requested */
524 code[1] = vmf->vmf_trapno & 0xff;
526 vmf->vmf_ip = (uintptr_t)code;
531 stack[0] = MAKE_VEC(0, (uintptr_t)code);
533 vmf->vmf_sp = (uintptr_t)stack;
535 vmf->kernel_fs = vmf->kernel_es = vmf->kernel_ds = 0;
536 vmf->vmf_eflags = PSL_VIF | PSL_VM | PSL_USER;
538 vm86 = &curpcb->pcb_ext->ext_vm86;
539 if (!vm86->vm86_has_vme)
540 vm86->vm86_eflags = vmf->vmf_eflags; /* save VIF, VIP */
544 * vm86 trap handler; determines whether routine succeeded or not.
545 * Called while in vm86 space, returns to calling process.
548 vm86_trap(struct vm86frame *vmf)
552 /* "should not happen" */
553 if ((vmf->vmf_eflags & PSL_VM) == 0)
554 panic("vm86_trap called, but not in vm86 mode");
556 addr = MAKE_ADDR(vmf->vmf_cs, vmf->vmf_ip);
557 if (*(u_char *)addr == HLT)
558 vmf->vmf_trapno = vmf->vmf_eflags & PSL_C;
560 vmf->vmf_trapno = vmf->vmf_trapno << 16;
566 vm86_intcall(int intnum, struct vm86frame *vmf)
570 if (intnum < 0 || intnum > 0xff)
573 vmf->vmf_trapno = intnum;
574 mtx_lock(&vm86_lock);
576 retval = vm86_bioscall(vmf);
578 mtx_unlock(&vm86_lock);
583 * struct vm86context contains the page table to use when making
584 * vm86 calls. If intnum is a valid interrupt number (0-255), then
585 * the "interrupt trampoline" will be used, otherwise we use the
586 * caller's cs:ip routine.
589 vm86_datacall(intnum, vmf, vmc)
591 struct vm86frame *vmf;
592 struct vm86context *vmc;
594 pt_entry_t *pte = (pt_entry_t *)vm86paddr;
596 int i, entry, retval;
598 mtx_lock(&vm86_lock);
599 for (i = 0; i < vmc->npages; i++) {
600 page = vtophys(vmc->pmap[i].kva & PG_FRAME);
601 entry = vmc->pmap[i].pte_num;
602 vmc->pmap[i].old_pte = pte[entry];
603 pte[entry] = page | PG_V | PG_RW | PG_U;
604 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
607 vmf->vmf_trapno = intnum;
609 retval = vm86_bioscall(vmf);
612 for (i = 0; i < vmc->npages; i++) {
613 entry = vmc->pmap[i].pte_num;
614 pte[entry] = vmc->pmap[i].old_pte;
615 pmap_invalidate_page(kernel_pmap, vmc->pmap[i].kva);
617 mtx_unlock(&vm86_lock);
623 vm86_getaddr(struct vm86context *vmc, u_short sel, u_short off)
628 addr = (vm_offset_t)MAKE_ADDR(sel, off);
629 page = addr >> PAGE_SHIFT;
630 for (i = 0; i < vmc->npages; i++)
631 if (page == vmc->pmap[i].pte_num)
632 return (vmc->pmap[i].kva + (addr & PAGE_MASK));
637 vm86_getptr(vmc, kva, sel, off)
638 struct vm86context *vmc;
645 for (i = 0; i < vmc->npages; i++)
646 if (kva >= vmc->pmap[i].kva &&
647 kva < vmc->pmap[i].kva + PAGE_SIZE) {
648 *off = kva - vmc->pmap[i].kva;
649 *sel = vmc->pmap[i].pte_num << 8;
653 panic("vm86_getptr: address not found");
657 vm86_sysarch(td, args)
662 struct i386_vm86_args ua;
663 struct vm86_kernel *vm86;
665 if ((error = copyin(args, &ua, sizeof(struct i386_vm86_args))) != 0)
668 if (td->td_pcb->pcb_ext == 0)
669 if ((error = i386_extend_pcb(td)) != 0)
671 vm86 = &td->td_pcb->pcb_ext->ext_vm86;
675 struct vm86_init_args sa;
677 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))) != 0)
679 if (cpu_feature & CPUID_VME)
680 vm86->vm86_has_vme = (rcr4() & CR4_VME ? 1 : 0);
682 vm86->vm86_has_vme = 0;
683 vm86->vm86_inited = 1;
684 vm86->vm86_debug = sa.debug;
685 bcopy(&sa.int_map, vm86->vm86_intmap, 32);
691 struct vm86_vme_args sa;
693 if ((cpu_feature & CPUID_VME) == 0)
696 if (error = copyin(ua.sub_args, &sa, sizeof(sa)))
699 load_cr4(rcr4() | CR4_VME);
701 load_cr4(rcr4() & ~CR4_VME);
707 struct vm86_vme_args sa;
709 sa.state = (rcr4() & CR4_VME ? 1 : 0);
710 error = copyout(&sa, ua.sub_args, sizeof(sa));
715 struct vm86_intcall_args sa;
717 if ((error = priv_check(td, PRIV_VM86_INTCALL)))
719 if ((error = copyin(ua.sub_args, &sa, sizeof(sa))))
721 if ((error = vm86_intcall(sa.intnum, &sa.vmf)))
723 error = copyout(&sa, ua.sub_args, sizeof(sa));