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/*
* vmx_intercept.c: Handle performance critical I/O packets in hypervisor space
* Copyright (c) 2004, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place - Suite 330, Boston, MA 02111-1307 USA.
*
*/
#include <xen/config.h>
#include <xen/types.h>
#include <asm/vmx.h>
#include <asm/vmx_platform.h>
#include <asm/vmx_virpit.h>
#include <asm/vmx_intercept.h>
#include <public/io/ioreq.h>
#include <xen/lib.h>
#include <xen/sched.h>
#include <asm/current.h>
#ifdef CONFIG_VMX
/* Check if the request is handled inside xen
return value: 0 --not handled; 1 --handled */
int vmx_io_intercept(ioreq_t *p, int type)
{
struct vcpu *d = current;
struct vmx_handler_t *handler = &(d->domain->arch.vmx_platform.vmx_handler);
int i;
unsigned long addr, offset;
for (i = 0; i < handler->num_slot; i++) {
if( type != handler->hdl_list[i].type)
continue;
addr = handler->hdl_list[i].addr;
offset = handler->hdl_list[i].offset;
if (p->addr >= addr &&
p->addr < addr + offset)
return handler->hdl_list[i].action(p);
}
return 0;
}
int register_io_handler(unsigned long addr, unsigned long offset,
intercept_action_t action, int type)
{
struct vcpu *d = current;
struct vmx_handler_t *handler = &(d->domain->arch.vmx_platform.vmx_handler);
int num = handler->num_slot;
if (num >= MAX_IO_HANDLER) {
printk("no extra space, register io interceptor failed!\n");
domain_crash_synchronous();
}
handler->hdl_list[num].addr = addr;
handler->hdl_list[num].offset = offset;
handler->hdl_list[num].action = action;
handler->hdl_list[num].type = type;
handler->num_slot++;
return 1;
}
static void pit_cal_count(struct vmx_virpit_t *vpit)
{
unsigned int usec_delta = (unsigned int)((NOW() - vpit->inject_point) / 1000);
if (usec_delta > vpit->period * 1000)
VMX_DBG_LOG(DBG_LEVEL_1, "VMX_PIT:long time has passed from last injection!");
vpit->count = vpit->init_val - ((usec_delta * PIT_FREQ / 1000000) % vpit->init_val );
}
static void pit_latch_io(struct vmx_virpit_t *vpit)
{
pit_cal_count(vpit);
switch(vpit->read_state) {
case MSByte:
vpit->count_MSB_latched=1;
break;
case LSByte:
vpit->count_LSB_latched=1;
break;
case LSByte_multiple:
vpit->count_LSB_latched=1;
vpit->count_MSB_latched=1;
break;
case MSByte_multiple:
VMX_DBG_LOG(DBG_LEVEL_1, "VMX_PIT:latch PIT counter before MSB_multiple!");
vpit->read_state=LSByte_multiple;
vpit->count_LSB_latched=1;
vpit->count_MSB_latched=1;
break;
default:
BUG();
}
}
static int pit_read_io(struct vmx_virpit_t *vpit)
{
if(vpit->count_LSB_latched) {
/* Read Least Significant Byte */
if(vpit->read_state==LSByte_multiple) {
vpit->read_state=MSByte_multiple;
}
vpit->count_LSB_latched=0;
return (vpit->count & 0xFF);
} else if(vpit->count_MSB_latched) {
/* Read Most Significant Byte */
if(vpit->read_state==MSByte_multiple) {
vpit->read_state=LSByte_multiple;
}
vpit->count_MSB_latched=0;
return ((vpit->count>>8) & 0xFF);
} else {
/* Unlatched Count Read */
VMX_DBG_LOG(DBG_LEVEL_1, "VMX_PIT: unlatched read");
pit_cal_count(vpit);
if(!(vpit->read_state & 0x1)) {
/* Read Least Significant Byte */
if(vpit->read_state==LSByte_multiple) {
vpit->read_state=MSByte_multiple;
}
return (vpit->count & 0xFF);
} else {
/* Read Most Significant Byte */
if(vpit->read_state==MSByte_multiple) {
vpit->read_state=LSByte_multiple;
}
return ((vpit->count>>8) & 0xFF);
}
}
}
/* vmx_io_assist light-weight version, specific to PIT DM */
static void resume_pit_io(ioreq_t *p)
{
struct cpu_user_regs *regs = guest_cpu_user_regs();
unsigned long old_eax = regs->eax;
p->state = STATE_INVALID;
switch(p->size) {
case 1:
regs->eax = (old_eax & 0xffffff00) | (p->u.data & 0xff);
break;
case 2:
regs->eax = (old_eax & 0xffff0000) | (p->u.data & 0xffff);
break;
case 4:
regs->eax = (p->u.data & 0xffffffff);
break;
default:
BUG();
}
}
/* the intercept action for PIT DM retval:0--not handled; 1--handled */
int intercept_pit_io(ioreq_t *p)
{
struct vcpu *d = current;
struct vmx_virpit_t *vpit = &(d->domain->arch.vmx_platform.vmx_pit);
if (p->size != 1 ||
p->pdata_valid ||
p->port_mm)
return 0;
if (p->addr == 0x43 &&
p->dir == 0 && /* write */
((p->u.data >> 4) & 0x3) == 0 && /* latch command */
((p->u.data >> 6) & 0x3) == (vpit->channel)) {/* right channel */
pit_latch_io(vpit);
return 1;
}
if (p->addr == (0x40 + vpit->channel) &&
p->dir == 1) { /* read */
p->u.data = pit_read_io(vpit);
resume_pit_io(p);
return 1;
}
return 0;
}
/* hooks function for the PIT initialization response iopacket */
static void pit_timer_fn(void *data)
{
struct vmx_virpit_t *vpit = data;
/* Set the pending intr bit, and send evtchn notification to myself. */
if (test_and_set_bit(vpit->vector, vpit->intr_bitmap))
vpit->pending_intr_nr++; /* already set, then count the pending intr */
set_ac_timer(&vpit->pit_timer, NOW() + MILLISECS(vpit->period));
}
/* Only some PIT operations such as load init counter need a hypervisor hook.
* leave all other operations in user space DM
*/
void vmx_hooks_assist(struct vcpu *d)
{
vcpu_iodata_t * vio = get_vio(d->domain, d->vcpu_id);
ioreq_t *p = &vio->vp_ioreq;
unsigned long *intr = &(vio->vp_intr[0]);
struct vmx_virpit_t *vpit = &(d->domain->arch.vmx_platform.vmx_pit);
int rw_mode;
/* load init count*/
if (p->state == STATE_IORESP_HOOK) {
/* set up actimer, handle re-init */
if ( active_ac_timer(&(vpit->pit_timer)) ) {
VMX_DBG_LOG(DBG_LEVEL_1, "VMX_PIT: guest reset PIT with channel %lx!\n", (unsigned long) ((p->u.data >> 24) & 0x3) );
rem_ac_timer(&(vpit->pit_timer));
}
else
init_ac_timer(&vpit->pit_timer, pit_timer_fn, vpit, 0);
/* init count for this channel */
vpit->init_val = (p->u.data & 0xFFFF) ;
/* frequency(ms) of pit */
vpit->period = DIV_ROUND(((vpit->init_val) * 1000), PIT_FREQ);
if (vpit->period < 1) {
printk("VMX_PIT: guest programmed too small an init_val: %x\n",
vpit->init_val);
vpit->period = 1;
}
vpit->vector = ((p->u.data >> 16) & 0xFF);
vpit->channel = ((p->u.data >> 24) & 0x3);
vpit->first_injected = 0;
vpit->count_LSB_latched = 0;
vpit->count_MSB_latched = 0;
rw_mode = ((p->u.data >> 26) & 0x3);
switch(rw_mode) {
case 0x1:
vpit->read_state=LSByte;
break;
case 0x2:
vpit->read_state=MSByte;
break;
case 0x3:
vpit->read_state=LSByte_multiple;
break;
default:
printk("VMX_PIT:wrong PIT rw_mode!\n");
break;
}
vpit->intr_bitmap = intr;
set_ac_timer(&vpit->pit_timer, NOW() + MILLISECS(vpit->period));
/*restore the state*/
p->state = STATE_IORESP_READY;
/* register handler to intercept the PIT io when vm_exit */
register_portio_handler(0x40, 4, intercept_pit_io);
}
}
#endif /* CONFIG_VMX */
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