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47f7be394a
qemu/hw/ioapic.c
Jan Kiszka 47f7be394a ioapic: Do not set irr for masked edge IRQs 
So far we set IRR for edge IRQs even if the pin is masked. If the guest
later on unmasks and switches the pin to level-triggered mode, irr will
remain set, causing an IRQ storm. The point is that setting IRR is not
correct in this case according to the spec, and avoiding this resolves
the issue.

Reported-and-tested-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2011-04-27 20:04:51 +02:00

360 lines
10 KiB
C
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/*
* ioapic.c IOAPIC emulation logic
*
* Copyright (c) 2004-2005 Fabrice Bellard
*
* Split the ioapic logic from apic.c
* Xiantao Zhang <xiantao.zhang@intel.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, see <http://www.gnu.org/licenses/>.
*/
#include "hw.h"
#include "pc.h"
#include "apic.h"
#include "ioapic.h"
#include "qemu-timer.h"
#include "host-utils.h"
#include "sysbus.h"
//#define DEBUG_IOAPIC
#ifdef DEBUG_IOAPIC
#define DPRINTF(fmt, ...) \
do { printf("ioapic: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...)
#endif
#define MAX_IOAPICS 1
#define IOAPIC_VERSION 0x11
#define IOAPIC_LVT_DEST_SHIFT 56
#define IOAPIC_LVT_MASKED_SHIFT 16
#define IOAPIC_LVT_TRIGGER_MODE_SHIFT 15
#define IOAPIC_LVT_REMOTE_IRR_SHIFT 14
#define IOAPIC_LVT_POLARITY_SHIFT 13
#define IOAPIC_LVT_DELIV_STATUS_SHIFT 12
#define IOAPIC_LVT_DEST_MODE_SHIFT 11
#define IOAPIC_LVT_DELIV_MODE_SHIFT 8
#define IOAPIC_LVT_MASKED (1 << IOAPIC_LVT_MASKED_SHIFT)
#define IOAPIC_LVT_REMOTE_IRR (1 << IOAPIC_LVT_REMOTE_IRR_SHIFT)
#define IOAPIC_TRIGGER_EDGE 0
#define IOAPIC_TRIGGER_LEVEL 1
/*io{apic,sapic} delivery mode*/
#define IOAPIC_DM_FIXED 0x0
#define IOAPIC_DM_LOWEST_PRIORITY 0x1
#define IOAPIC_DM_PMI 0x2
#define IOAPIC_DM_NMI 0x4
#define IOAPIC_DM_INIT 0x5
#define IOAPIC_DM_SIPI 0x6
#define IOAPIC_DM_EXTINT 0x7
#define IOAPIC_DM_MASK 0x7
#define IOAPIC_VECTOR_MASK 0xff
#define IOAPIC_IOREGSEL 0x00
#define IOAPIC_IOWIN 0x10
#define IOAPIC_REG_ID 0x00
#define IOAPIC_REG_VER 0x01
#define IOAPIC_REG_ARB 0x02
#define IOAPIC_REG_REDTBL_BASE 0x10
#define IOAPIC_ID 0x00
#define IOAPIC_ID_SHIFT 24
#define IOAPIC_ID_MASK 0xf
#define IOAPIC_VER_ENTRIES_SHIFT 16
typedef struct IOAPICState IOAPICState;
struct IOAPICState {
SysBusDevice busdev;
uint8_t id;
uint8_t ioregsel;
uint32_t irr;
uint64_t ioredtbl[IOAPIC_NUM_PINS];
};
static IOAPICState *ioapics[MAX_IOAPICS];
static void ioapic_service(IOAPICState *s)
{
uint8_t i;
uint8_t trig_mode;
uint8_t vector;
uint8_t delivery_mode;
uint32_t mask;
uint64_t entry;
uint8_t dest;
uint8_t dest_mode;
uint8_t polarity;
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
mask = 1 << i;
if (s->irr & mask) {
entry = s->ioredtbl[i];
if (!(entry & IOAPIC_LVT_MASKED)) {
trig_mode = ((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1);
dest = entry >> IOAPIC_LVT_DEST_SHIFT;
dest_mode = (entry >> IOAPIC_LVT_DEST_MODE_SHIFT) & 1;
delivery_mode =
(entry >> IOAPIC_LVT_DELIV_MODE_SHIFT) & IOAPIC_DM_MASK;
polarity = (entry >> IOAPIC_LVT_POLARITY_SHIFT) & 1;
if (trig_mode == IOAPIC_TRIGGER_EDGE) {
s->irr &= ~mask;
} else {
s->ioredtbl[i] |= IOAPIC_LVT_REMOTE_IRR;
}
if (delivery_mode == IOAPIC_DM_EXTINT) {
vector = pic_read_irq(isa_pic);
} else {
vector = entry & IOAPIC_VECTOR_MASK;
}
apic_deliver_irq(dest, dest_mode, delivery_mode,
vector, polarity, trig_mode);
}
}
}
}
static void ioapic_set_irq(void *opaque, int vector, int level)
{
IOAPICState *s = opaque;
/* ISA IRQs map to GSI 1-1 except for IRQ0 which maps
* to GSI 2. GSI maps to ioapic 1-1. This is not
* the cleanest way of doing it but it should work. */
DPRINTF("%s: %s vec %x\n", __func__, level ? "raise" : "lower", vector);
if (vector == 0) {
vector = 2;
}
if (vector >= 0 && vector < IOAPIC_NUM_PINS) {
uint32_t mask = 1 << vector;
uint64_t entry = s->ioredtbl[vector];
if (((entry >> IOAPIC_LVT_TRIGGER_MODE_SHIFT) & 1) ==
IOAPIC_TRIGGER_LEVEL) {
/* level triggered */
if (level) {
s->irr |= mask;
ioapic_service(s);
} else {
s->irr &= ~mask;
}
} else {
/* According to the 82093AA manual, we must ignore edge requests
* if the input pin is masked. */
if (level && !(entry & IOAPIC_LVT_MASKED)) {
s->irr |= mask;
ioapic_service(s);
}
}
}
}
void ioapic_eoi_broadcast(int vector)
{
IOAPICState *s;
uint64_t entry;
int i, n;
for (i = 0; i < MAX_IOAPICS; i++) {
s = ioapics[i];
if (!s) {
continue;
}
for (n = 0; n < IOAPIC_NUM_PINS; n++) {
entry = s->ioredtbl[n];
if ((entry & IOAPIC_LVT_REMOTE_IRR)
&& (entry & IOAPIC_VECTOR_MASK) == vector) {
s->ioredtbl[n] = entry & ~IOAPIC_LVT_REMOTE_IRR;
if (!(entry & IOAPIC_LVT_MASKED) && (s->irr & (1 << n))) {
ioapic_service(s);
}
}
}
}
}
static uint32_t ioapic_mem_readl(void *opaque, target_phys_addr_t addr)
{
IOAPICState *s = opaque;
int index;
uint32_t val = 0;
switch (addr & 0xff) {
case IOAPIC_IOREGSEL:
val = s->ioregsel;
break;
case IOAPIC_IOWIN:
switch (s->ioregsel) {
case IOAPIC_REG_ID:
val = s->id << IOAPIC_ID_SHIFT;
break;
case IOAPIC_REG_VER:
val = IOAPIC_VERSION |
((IOAPIC_NUM_PINS - 1) << IOAPIC_VER_ENTRIES_SHIFT);
break;
case IOAPIC_REG_ARB:
val = 0;
break;
default:
index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
if (index >= 0 && index < IOAPIC_NUM_PINS) {
if (s->ioregsel & 1) {
val = s->ioredtbl[index] >> 32;
} else {
val = s->ioredtbl[index] & 0xffffffff;
}
}
}
DPRINTF("read: %08x = %08x\n", s->ioregsel, val);
break;
}
return val;
}
static void
ioapic_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val)
{
IOAPICState *s = opaque;
int index;
switch (addr & 0xff) {
case IOAPIC_IOREGSEL:
s->ioregsel = val;
break;
case IOAPIC_IOWIN:
DPRINTF("write: %08x = %08x\n", s->ioregsel, val);
switch (s->ioregsel) {
case IOAPIC_REG_ID:
s->id = (val >> IOAPIC_ID_SHIFT) & IOAPIC_ID_MASK;
break;
case IOAPIC_REG_VER:
case IOAPIC_REG_ARB:
break;
default:
index = (s->ioregsel - IOAPIC_REG_REDTBL_BASE) >> 1;
if (index >= 0 && index < IOAPIC_NUM_PINS) {
if (s->ioregsel & 1) {
s->ioredtbl[index] &= 0xffffffff;
s->ioredtbl[index] |= (uint64_t)val << 32;
} else {
s->ioredtbl[index] &= ~0xffffffffULL;
s->ioredtbl[index] |= val;
}
ioapic_service(s);
}
}
break;
}
}
static int ioapic_post_load(void *opaque, int version_id)
{
IOAPICState *s = opaque;
if (version_id == 1) {
/* set sane value */
s->irr = 0;
}
return 0;
}
static const VMStateDescription vmstate_ioapic = {
.name = "ioapic",
.version_id = 3,
.post_load = ioapic_post_load,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(id, IOAPICState),
VMSTATE_UINT8(ioregsel, IOAPICState),
VMSTATE_UNUSED_V(2, 8), /* to account for qemu-kvm's v2 format */
VMSTATE_UINT32_V(irr, IOAPICState, 2),
VMSTATE_UINT64_ARRAY(ioredtbl, IOAPICState, IOAPIC_NUM_PINS),
VMSTATE_END_OF_LIST()
}
};
static void ioapic_reset(DeviceState *d)
{
IOAPICState *s = DO_UPCAST(IOAPICState, busdev.qdev, d);
int i;
s->id = 0;
s->ioregsel = 0;
s->irr = 0;
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
s->ioredtbl[i] = 1 << IOAPIC_LVT_MASKED_SHIFT;
}
}
static CPUReadMemoryFunc * const ioapic_mem_read[3] = {
ioapic_mem_readl,
ioapic_mem_readl,
ioapic_mem_readl,
};
static CPUWriteMemoryFunc * const ioapic_mem_write[3] = {
ioapic_mem_writel,
ioapic_mem_writel,
ioapic_mem_writel,
};
static int ioapic_init1(SysBusDevice *dev)
{
IOAPICState *s = FROM_SYSBUS(IOAPICState, dev);
int io_memory;
static int ioapic_no;
if (ioapic_no >= MAX_IOAPICS) {
return -1;
}
io_memory = cpu_register_io_memory(ioapic_mem_read,
ioapic_mem_write, s,
DEVICE_NATIVE_ENDIAN);
sysbus_init_mmio(dev, 0x1000, io_memory);
qdev_init_gpio_in(&dev->qdev, ioapic_set_irq, IOAPIC_NUM_PINS);
ioapics[ioapic_no++] = s;
return 0;
}
static SysBusDeviceInfo ioapic_info = {
.init = ioapic_init1,
.qdev.name = "ioapic",
.qdev.size = sizeof(IOAPICState),
.qdev.vmsd = &vmstate_ioapic,
.qdev.reset = ioapic_reset,
.qdev.no_user = 1,
};
static void ioapic_register_devices(void)
{
sysbus_register_withprop(&ioapic_info);
}
device_init(ioapic_register_devices)
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