/* $OpenBSD: kvm86.c,v 1.3 2007/02/20 21:15:01 tom Exp $ */
/* $NetBSD: kvm86.c,v 1.10 2005/12/26 19:23:59 perry Exp $ */
/*
* Copyright (c) 2002
* Matthias Drochner. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/simplelock.h>
#include <uvm/uvm_extern.h>
#include <uvm/uvm.h>
#include <machine/pcb.h>
#include <machine/pte.h>
#include <machine/pmap.h>
#include <machine/kvm86.h>
#include <machine/cpu.h>
/* assembler functions in kvm86call.s */
extern int kvm86_call(struct trapframe *);
extern void kvm86_ret(struct trapframe *, int);
#define PGTABLE_SIZE ((1024 + 64) * 1024 / PAGE_SIZE)
struct kvm86_data {
pt_entry_t pgtbl[PGTABLE_SIZE];
struct segment_descriptor sd;
struct pcb pcb;
u_long iomap[0x10000/32];
};
void kvm86_map(struct kvm86_data *, paddr_t, uint32_t);
void kvm86_mapbios(struct kvm86_data *);
void kvm86_prepare(struct kvm86_data *vmd);
/*
* global VM for BIOS calls
*/
struct kvm86_data *bioscallvmd;
/* page for trampoline and stack */
void *bioscallscratchpage;
/* where this page is mapped in the vm86 */
#define BIOSCALLSCRATCHPAGE_VMVA 0x1000
/* a virtual page to map in vm86 memory temporarily */
vaddr_t bioscalltmpva;
struct mutex kvm86_mp_mutex;
#define KVM86_IOPL3 /* not strictly necessary, saves a lot of traps */
void
kvm86_init()
{
size_t vmdsize;
char *buf;
struct kvm86_data *vmd;
struct pcb *pcb;
paddr_t pa;
int i;
vmdsize = round_page(sizeof(struct kvm86_data)) + PAGE_SIZE;
if ((buf = (char *)uvm_km_zalloc(kernel_map, vmdsize)) == NULL)
return;
/* first page is stack */
vmd = (struct kvm86_data *)(buf + PAGE_SIZE);
pcb = &vmd->pcb;
/*
* derive pcb and TSS from proc0
* we want to access all IO ports, so we need a full-size
* permission bitmap
* XXX do we really need the pcb or just the TSS?
*/
memcpy(pcb, &proc0.p_addr->u_pcb, sizeof(struct pcb));
pcb->pcb_tss.tss_esp0 = (int)vmd;
pcb->pcb_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
for (i = 0; i < sizeof(vmd->iomap) / 4; i++)
vmd->iomap[i] = 0;
pcb->pcb_tss.tss_ioopt =
((caddr_t)vmd->iomap - (caddr_t)&pcb->pcb_tss) << 16;
/* setup TSS descriptor (including our iomap) */
setsegment(&vmd->sd, &pcb->pcb_tss,
sizeof(struct pcb) + sizeof(vmd->iomap) - 1,
SDT_SYS386TSS, SEL_KPL, 0, 0);
/* prepare VM for BIOS calls */
kvm86_mapbios(vmd);
if ((bioscallscratchpage = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE))
== 0)
return;
pmap_extract(pmap_kernel(), (vaddr_t)bioscallscratchpage, &pa);
kvm86_map(vmd, pa, BIOSCALLSCRATCHPAGE_VMVA);
bioscallvmd = vmd;
bioscalltmpva = uvm_km_alloc(kernel_map, PAGE_SIZE);
mtx_init(&kvm86_mp_mutex, IPL_IPI);
}
/*
* XXX pass some stuff to the assembler code
* XXX this should be done cleanly (in call argument to kvm86_call())
*/
volatile struct pcb *vm86pcb;
volatile int vm86tssd0, vm86tssd1;
volatile paddr_t vm86newptd;
volatile struct trapframe *vm86frame;
volatile pt_entry_t *vm86pgtableva;
void
kvm86_prepare(struct kvm86_data *vmd)
{
vm86newptd = vtophys((vaddr_t)vmd) | PG_V | PG_RW | PG_U | PG_u;
vm86pgtableva = vmd->pgtbl;
vm86frame = (struct trapframe *)vmd - 1;
vm86pcb = &vmd->pcb;
vm86tssd0 = *(int*)&vmd->sd;
vm86tssd1 = *((int*)&vmd->sd + 1);
}
void
kvm86_map(struct kvm86_data *vmd, paddr_t pa, uint32_t vmva)
{
vmd->pgtbl[vmva >> 12] = pa | PG_V | PG_RW | PG_U | PG_u;
}
void
kvm86_mapbios(struct kvm86_data *vmd)
{
paddr_t pa;
/* map first physical page (vector table, BIOS data) */
kvm86_map(vmd, 0, 0);
/* map ISA hole */
for (pa = 0xa0000; pa < 0x100000; pa += PAGE_SIZE)
kvm86_map(vmd, pa, pa);
}
void *
kvm86_bios_addpage(uint32_t vmva)
{
void *mem;
paddr_t pa;
if (bioscallvmd->pgtbl[vmva >> 12]) /* allocated? */
return (NULL);
if ((mem = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE)) == NULL)
return (NULL);
pmap_extract(pmap_kernel(), (vaddr_t)mem, &pa);
kvm86_map(bioscallvmd, pa, vmva);
return (mem);
}
void
kvm86_bios_delpage(uint32_t vmva, void *kva)
{
bioscallvmd->pgtbl[vmva >> 12] = 0;
uvm_km_free(kernel_map, (vaddr_t)kva, PAGE_SIZE);
}
size_t
kvm86_bios_read(u_int32_t vmva, char *buf, size_t len)
{
size_t todo, now;
paddr_t vmpa;
todo = len;
while (todo > 0) {
now = min(todo, PAGE_SIZE - (vmva & (PAGE_SIZE - 1)));
if (!bioscallvmd->pgtbl[vmva >> 12])
break;
vmpa = bioscallvmd->pgtbl[vmva >> 12] & ~(PAGE_SIZE - 1);
pmap_kenter_pa(bioscalltmpva, vmpa, VM_PROT_READ);
pmap_update(pmap_kernel());
memcpy(buf, (void *)(bioscalltmpva + (vmva & (PAGE_SIZE - 1))),
now);
buf += now;
todo -= now;
vmva += now;
}
return (len - todo);
}
int
kvm86_bioscall(int intno, struct trapframe *tf)
{
static const unsigned char call[] = {
0xfa, /* CLI */
0xcd, /* INTxx */
0,
0xfb, /* STI */
0xf4 /* HLT */
};
memcpy(bioscallscratchpage, call, sizeof(call));
*((unsigned char *)bioscallscratchpage + 2) = intno;
tf->tf_eip = BIOSCALLSCRATCHPAGE_VMVA;
tf->tf_cs = 0;
tf->tf_esp = BIOSCALLSCRATCHPAGE_VMVA + PAGE_SIZE - 2;
tf->tf_ss = 0;
tf->tf_eflags = PSL_USERSET | PSL_VM;
#ifdef KVM86_IOPL3
tf->tf_eflags |= PSL_IOPL;
#endif
tf->tf_ds = tf->tf_es = tf->tf_fs = tf->tf_gs = 0;
kvm86_prepare(bioscallvmd); /* XXX */
return (kvm86_call(tf));
}
int
kvm86_simplecall(int no, struct kvm86regs *regs)
{
struct trapframe tf;
int res;
memset(&tf, 0, sizeof(struct trapframe));
tf.tf_eax = regs->eax;
tf.tf_ebx = regs->ebx;
tf.tf_ecx = regs->ecx;
tf.tf_edx = regs->edx;
tf.tf_esi = regs->esi;
tf.tf_edi = regs->edi;
tf.tf_vm86_es = regs->es;
mtx_enter(&kvm86_mp_mutex);
res = kvm86_bioscall(no, &tf);
mtx_leave(&kvm86_mp_mutex);
regs->eax = tf.tf_eax;
regs->ebx = tf.tf_ebx;
regs->ecx = tf.tf_ecx;
regs->edx = tf.tf_edx;
regs->esi = tf.tf_esi;
regs->edi = tf.tf_edi;
regs->es = tf.tf_vm86_es;
regs->eflags = tf.tf_eflags;
return (res);
}
void
kvm86_gpfault(struct trapframe *tf)
{
unsigned char *kva, insn, trapno;
uint16_t *sp;
kva = (unsigned char *)((tf->tf_cs << 4) + tf->tf_eip);
insn = *kva;
#ifdef KVM86DEBUG
printf("kvm86_gpfault: cs=%x, eip=%x, insn=%x, eflags=%x\n",
tf->tf_cs, tf->tf_eip, insn, tf->tf_eflags);
#endif
KASSERT(tf->tf_eflags & PSL_VM);
switch (insn) {
case 0xf4: /* HLT - normal exit */
kvm86_ret(tf, 0);
break;
case 0xcd: /* INTxx */
/* fake a return stack frame and call real mode handler */
trapno = *(kva + 1);
sp = (uint16_t *)((tf->tf_ss << 4) + tf->tf_esp);
*(--sp) = tf->tf_eflags;
*(--sp) = tf->tf_cs;
*(--sp) = tf->tf_eip + 2;
tf->tf_esp -= 6;
tf->tf_cs = *(uint16_t *)(trapno * 4 + 2);
tf->tf_eip = *(uint16_t *)(trapno * 4);
break;
case 0xcf: /* IRET */
sp = (uint16_t *)((tf->tf_ss << 4) + tf->tf_esp);
tf->tf_eip = *(sp++);
tf->tf_cs = *(sp++);
tf->tf_eflags = *(sp++);
tf->tf_esp += 6;
tf->tf_eflags |= PSL_VM; /* outside of 16bit flag reg */
break;
#ifndef KVM86_IOPL3 /* XXX check VME? */
case 0xfa: /* CLI */
case 0xfb: /* STI */
/* XXX ignore for now */
tf->tf_eip++;
break;
case 0x9c: /* PUSHF */
sp = (uint16_t *)((tf->tf_ss << 4) + tf->tf_esp);
*(--sp) = tf->tf_eflags;
tf->tf_esp -= 2;
tf->tf_eip++;
break;
case 0x9d: /* POPF */
sp = (uint16_t *)((tf->tf_ss << 4) + tf->tf_esp);
tf->tf_eflags = *(sp++);
tf->tf_esp += 2;
tf->tf_eip++;
tf->tf_eflags |= PSL_VM; /* outside of 16bit flag reg */
break;
#endif
default:
#ifdef KVM86DEBUG
printf("kvm86_gpfault: unhandled\n");
#else
printf("kvm86_gpfault: cs=%x, eip=%x, insn=%x, eflags=%x\n",
tf->tf_cs, tf->tf_eip, insn, tf->tf_eflags);
#endif
/*
* signal error to caller
*/
kvm86_ret(tf, -1);
break;
}
}