linux/virt/kvm/ioapic.c
Gleb Natapov b4a2f5e723 KVM: Avoid redelivery of edge interrupt before next edge
The check for an edge is broken in current ioapic code. ioapic->irr is
cleared on each edge interrupt by ioapic_service() and this makes
old_irr != ioapic->irr condition in kvm_ioapic_set_irq() to be always
true. The patch fixes the code to properly recognise edge.

Some HW emulation calls set_irq() without level change. If each such
call is propagated to an OS it may confuse a device driver. This is the
case with keyboard device emulation and Windows XP x64  installer on SMP VM.
Each keystroke produce two interrupts (down/up) one interrupt is
submitted to CPU0 and another to CPU1. This confuses Windows somehow
and it ignores keystrokes.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2009-08-09 11:45:49 +03:00

334 lines
8.2 KiB
C

/*
* Copyright (C) 2001 MandrakeSoft S.A.
*
* MandrakeSoft S.A.
* 43, rue d'Aboukir
* 75002 Paris - France
* http://www.linux-mandrake.com/
* http://www.mandrakesoft.com/
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Yunhong Jiang <yunhong.jiang@intel.com>
* Yaozu (Eddie) Dong <eddie.dong@intel.com>
* Based on Xen 3.1 code.
*/
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/smp.h>
#include <linux/hrtimer.h>
#include <linux/io.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/current.h>
#include "ioapic.h"
#include "lapic.h"
#include "irq.h"
#if 0
#define ioapic_debug(fmt,arg...) printk(KERN_WARNING fmt,##arg)
#else
#define ioapic_debug(fmt, arg...)
#endif
static int ioapic_deliver(struct kvm_ioapic *vioapic, int irq);
static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic,
unsigned long addr,
unsigned long length)
{
unsigned long result = 0;
switch (ioapic->ioregsel) {
case IOAPIC_REG_VERSION:
result = ((((IOAPIC_NUM_PINS - 1) & 0xff) << 16)
| (IOAPIC_VERSION_ID & 0xff));
break;
case IOAPIC_REG_APIC_ID:
case IOAPIC_REG_ARB_ID:
result = ((ioapic->id & 0xf) << 24);
break;
default:
{
u32 redir_index = (ioapic->ioregsel - 0x10) >> 1;
u64 redir_content;
ASSERT(redir_index < IOAPIC_NUM_PINS);
redir_content = ioapic->redirtbl[redir_index].bits;
result = (ioapic->ioregsel & 0x1) ?
(redir_content >> 32) & 0xffffffff :
redir_content & 0xffffffff;
break;
}
}
return result;
}
static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
{
union kvm_ioapic_redirect_entry *pent;
int injected = -1;
pent = &ioapic->redirtbl[idx];
if (!pent->fields.mask) {
injected = ioapic_deliver(ioapic, idx);
if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG)
pent->fields.remote_irr = 1;
}
return injected;
}
static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
{
unsigned index;
bool mask_before, mask_after;
switch (ioapic->ioregsel) {
case IOAPIC_REG_VERSION:
/* Writes are ignored. */
break;
case IOAPIC_REG_APIC_ID:
ioapic->id = (val >> 24) & 0xf;
break;
case IOAPIC_REG_ARB_ID:
break;
default:
index = (ioapic->ioregsel - 0x10) >> 1;
ioapic_debug("change redir index %x val %x\n", index, val);
if (index >= IOAPIC_NUM_PINS)
return;
mask_before = ioapic->redirtbl[index].fields.mask;
if (ioapic->ioregsel & 1) {
ioapic->redirtbl[index].bits &= 0xffffffff;
ioapic->redirtbl[index].bits |= (u64) val << 32;
} else {
ioapic->redirtbl[index].bits &= ~0xffffffffULL;
ioapic->redirtbl[index].bits |= (u32) val;
ioapic->redirtbl[index].fields.remote_irr = 0;
}
mask_after = ioapic->redirtbl[index].fields.mask;
if (mask_before != mask_after)
kvm_fire_mask_notifiers(ioapic->kvm, index, mask_after);
if (ioapic->redirtbl[index].fields.trig_mode == IOAPIC_LEVEL_TRIG
&& ioapic->irr & (1 << index))
ioapic_service(ioapic, index);
break;
}
}
static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
{
union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
struct kvm_lapic_irq irqe;
ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
"vector=%x trig_mode=%x\n",
entry->fields.dest, entry->fields.dest_mode,
entry->fields.delivery_mode, entry->fields.vector,
entry->fields.trig_mode);
irqe.dest_id = entry->fields.dest_id;
irqe.vector = entry->fields.vector;
irqe.dest_mode = entry->fields.dest_mode;
irqe.trig_mode = entry->fields.trig_mode;
irqe.delivery_mode = entry->fields.delivery_mode << 8;
irqe.level = 1;
irqe.shorthand = 0;
#ifdef CONFIG_X86
/* Always delivery PIT interrupt to vcpu 0 */
if (irq == 0) {
irqe.dest_mode = 0; /* Physical mode. */
irqe.dest_id = ioapic->kvm->vcpus[0]->vcpu_id;
}
#endif
return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);
}
int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
{
u32 old_irr = ioapic->irr;
u32 mask = 1 << irq;
union kvm_ioapic_redirect_entry entry;
int ret = 1;
if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
entry = ioapic->redirtbl[irq];
level ^= entry.fields.polarity;
if (!level)
ioapic->irr &= ~mask;
else {
int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
ioapic->irr |= mask;
if ((edge && old_irr != ioapic->irr) ||
(!edge && !entry.fields.remote_irr))
ret = ioapic_service(ioapic, irq);
}
}
return ret;
}
static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int pin,
int trigger_mode)
{
union kvm_ioapic_redirect_entry *ent;
ent = &ioapic->redirtbl[pin];
kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
if (trigger_mode == IOAPIC_LEVEL_TRIG) {
ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
ent->fields.remote_irr = 0;
if (!ent->fields.mask && (ioapic->irr & (1 << pin)))
ioapic_service(ioapic, pin);
}
}
void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
int i;
for (i = 0; i < IOAPIC_NUM_PINS; i++)
if (ioapic->redirtbl[i].fields.vector == vector)
__kvm_ioapic_update_eoi(ioapic, i, trigger_mode);
}
static int ioapic_in_range(struct kvm_io_device *this, gpa_t addr,
int len, int is_write)
{
struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
return ((addr >= ioapic->base_address &&
(addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
}
static void ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
void *val)
{
struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
u32 result;
ioapic_debug("addr %lx\n", (unsigned long)addr);
ASSERT(!(addr & 0xf)); /* check alignment */
addr &= 0xff;
switch (addr) {
case IOAPIC_REG_SELECT:
result = ioapic->ioregsel;
break;
case IOAPIC_REG_WINDOW:
result = ioapic_read_indirect(ioapic, addr, len);
break;
default:
result = 0;
break;
}
switch (len) {
case 8:
*(u64 *) val = result;
break;
case 1:
case 2:
case 4:
memcpy(val, (char *)&result, len);
break;
default:
printk(KERN_WARNING "ioapic: wrong length %d\n", len);
}
}
static void ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
const void *val)
{
struct kvm_ioapic *ioapic = (struct kvm_ioapic *)this->private;
u32 data;
ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
(void*)addr, len, val);
ASSERT(!(addr & 0xf)); /* check alignment */
if (len == 4 || len == 8)
data = *(u32 *) val;
else {
printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
return;
}
addr &= 0xff;
switch (addr) {
case IOAPIC_REG_SELECT:
ioapic->ioregsel = data;
break;
case IOAPIC_REG_WINDOW:
ioapic_write_indirect(ioapic, data);
break;
#ifdef CONFIG_IA64
case IOAPIC_REG_EOI:
kvm_ioapic_update_eoi(ioapic->kvm, data, IOAPIC_LEVEL_TRIG);
break;
#endif
default:
break;
}
}
void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
{
int i;
for (i = 0; i < IOAPIC_NUM_PINS; i++)
ioapic->redirtbl[i].fields.mask = 1;
ioapic->base_address = IOAPIC_DEFAULT_BASE_ADDRESS;
ioapic->ioregsel = 0;
ioapic->irr = 0;
ioapic->id = 0;
}
int kvm_ioapic_init(struct kvm *kvm)
{
struct kvm_ioapic *ioapic;
ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
if (!ioapic)
return -ENOMEM;
kvm->arch.vioapic = ioapic;
kvm_ioapic_reset(ioapic);
ioapic->dev.read = ioapic_mmio_read;
ioapic->dev.write = ioapic_mmio_write;
ioapic->dev.in_range = ioapic_in_range;
ioapic->dev.private = ioapic;
ioapic->kvm = kvm;
kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
return 0;
}