https://github.com/torvalds/linux
Tip revision: 9eccca0843205f87c00404b663188b88eb248051 authored by Linus Torvalds on 08 March 2015, 23:09:09 UTC
Linux 4.0-rc3
Linux 4.0-rc3
Tip revision: 9eccca0
ioapic.c
/*
* Copyright (C) 2001 MandrakeSoft S.A.
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* 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 <linux/slab.h>
#include <linux/export.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/current.h>
#include <trace/events/kvm.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_service(struct kvm_ioapic *vioapic, int irq,
bool line_status);
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;
if (redir_index < IOAPIC_NUM_PINS)
redir_content =
ioapic->redirtbl[redir_index].bits;
else
redir_content = ~0ULL;
result = (ioapic->ioregsel & 0x1) ?
(redir_content >> 32) & 0xffffffff :
redir_content & 0xffffffff;
break;
}
}
return result;
}
static void rtc_irq_eoi_tracking_reset(struct kvm_ioapic *ioapic)
{
ioapic->rtc_status.pending_eoi = 0;
bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS);
}
static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic);
static void rtc_status_pending_eoi_check_valid(struct kvm_ioapic *ioapic)
{
if (WARN_ON(ioapic->rtc_status.pending_eoi < 0))
kvm_rtc_eoi_tracking_restore_all(ioapic);
}
static void __rtc_irq_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
{
bool new_val, old_val;
struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
union kvm_ioapic_redirect_entry *e;
e = &ioapic->redirtbl[RTC_GSI];
if (!kvm_apic_match_dest(vcpu, NULL, 0, e->fields.dest_id,
e->fields.dest_mode))
return;
new_val = kvm_apic_pending_eoi(vcpu, e->fields.vector);
old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
if (new_val == old_val)
return;
if (new_val) {
__set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
ioapic->rtc_status.pending_eoi++;
} else {
__clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
ioapic->rtc_status.pending_eoi--;
rtc_status_pending_eoi_check_valid(ioapic);
}
}
void kvm_rtc_eoi_tracking_restore_one(struct kvm_vcpu *vcpu)
{
struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
spin_lock(&ioapic->lock);
__rtc_irq_eoi_tracking_restore_one(vcpu);
spin_unlock(&ioapic->lock);
}
static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
{
struct kvm_vcpu *vcpu;
int i;
if (RTC_GSI >= IOAPIC_NUM_PINS)
return;
rtc_irq_eoi_tracking_reset(ioapic);
kvm_for_each_vcpu(i, vcpu, ioapic->kvm)
__rtc_irq_eoi_tracking_restore_one(vcpu);
}
static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
{
if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map)) {
--ioapic->rtc_status.pending_eoi;
rtc_status_pending_eoi_check_valid(ioapic);
}
}
static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic)
{
if (ioapic->rtc_status.pending_eoi > 0)
return true; /* coalesced */
return false;
}
static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq,
int irq_level, bool line_status)
{
union kvm_ioapic_redirect_entry entry;
u32 mask = 1 << irq;
u32 old_irr;
int edge, ret;
entry = ioapic->redirtbl[irq];
edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG);
if (!irq_level) {
ioapic->irr &= ~mask;
ret = 1;
goto out;
}
/*
* Return 0 for coalesced interrupts; for edge-triggered interrupts,
* this only happens if a previous edge has not been delivered due
* do masking. For level interrupts, the remote_irr field tells
* us if the interrupt is waiting for an EOI.
*
* RTC is special: it is edge-triggered, but userspace likes to know
* if it has been already ack-ed via EOI because coalesced RTC
* interrupts lead to time drift in Windows guests. So we track
* EOI manually for the RTC interrupt.
*/
if (irq == RTC_GSI && line_status &&
rtc_irq_check_coalesced(ioapic)) {
ret = 0;
goto out;
}
old_irr = ioapic->irr;
ioapic->irr |= mask;
if ((edge && old_irr == ioapic->irr) ||
(!edge && entry.fields.remote_irr)) {
ret = 0;
goto out;
}
ret = ioapic_service(ioapic, irq, line_status);
out:
trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
return ret;
}
static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr)
{
u32 idx;
rtc_irq_eoi_tracking_reset(ioapic);
for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS)
ioapic_set_irq(ioapic, idx, 1, true);
kvm_rtc_eoi_tracking_restore_all(ioapic);
}
static void update_handled_vectors(struct kvm_ioapic *ioapic)
{
DECLARE_BITMAP(handled_vectors, 256);
int i;
memset(handled_vectors, 0, sizeof(handled_vectors));
for (i = 0; i < IOAPIC_NUM_PINS; ++i)
__set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
memcpy(ioapic->handled_vectors, handled_vectors,
sizeof(handled_vectors));
smp_wmb();
}
void kvm_ioapic_scan_entry(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap,
u32 *tmr)
{
struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
union kvm_ioapic_redirect_entry *e;
int index;
spin_lock(&ioapic->lock);
for (index = 0; index < IOAPIC_NUM_PINS; index++) {
e = &ioapic->redirtbl[index];
if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG ||
kvm_irq_has_notifier(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index) ||
index == RTC_GSI) {
if (kvm_apic_match_dest(vcpu, NULL, 0,
e->fields.dest_id, e->fields.dest_mode)) {
__set_bit(e->fields.vector,
(unsigned long *)eoi_exit_bitmap);
if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG)
__set_bit(e->fields.vector,
(unsigned long *)tmr);
}
}
}
spin_unlock(&ioapic->lock);
}
void kvm_vcpu_request_scan_ioapic(struct kvm *kvm)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
if (!ioapic)
return;
kvm_make_scan_ioapic_request(kvm);
}
static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
{
unsigned index;
bool mask_before, mask_after;
union kvm_ioapic_redirect_entry *e;
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;
e = &ioapic->redirtbl[index];
mask_before = e->fields.mask;
if (ioapic->ioregsel & 1) {
e->bits &= 0xffffffff;
e->bits |= (u64) val << 32;
} else {
e->bits &= ~0xffffffffULL;
e->bits |= (u32) val;
e->fields.remote_irr = 0;
}
update_handled_vectors(ioapic);
mask_after = e->fields.mask;
if (mask_before != mask_after)
kvm_fire_mask_notifiers(ioapic->kvm, KVM_IRQCHIP_IOAPIC, index, mask_after);
if (e->fields.trig_mode == IOAPIC_LEVEL_TRIG
&& ioapic->irr & (1 << index))
ioapic_service(ioapic, index, false);
kvm_vcpu_request_scan_ioapic(ioapic->kvm);
break;
}
}
static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
{
union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq];
struct kvm_lapic_irq irqe;
int ret;
if (entry->fields.mask)
return -1;
ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x "
"vector=%x trig_mode=%x\n",
entry->fields.dest_id, 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;
if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
ioapic->irr &= ~(1 << irq);
if (irq == RTC_GSI && line_status) {
/*
* pending_eoi cannot ever become negative (see
* rtc_status_pending_eoi_check_valid) and the caller
* ensures that it is only called if it is >= zero, namely
* if rtc_irq_check_coalesced returns false).
*/
BUG_ON(ioapic->rtc_status.pending_eoi != 0);
ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,
ioapic->rtc_status.dest_map);
ioapic->rtc_status.pending_eoi = (ret < 0 ? 0 : ret);
} else
ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL);
if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG)
entry->fields.remote_irr = 1;
return ret;
}
int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
int level, bool line_status)
{
int ret, irq_level;
BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS);
spin_lock(&ioapic->lock);
irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
irq_source_id, level);
ret = ioapic_set_irq(ioapic, irq, irq_level, line_status);
spin_unlock(&ioapic->lock);
return ret;
}
void kvm_ioapic_clear_all(struct kvm_ioapic *ioapic, int irq_source_id)
{
int i;
spin_lock(&ioapic->lock);
for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
__clear_bit(irq_source_id, &ioapic->irq_states[i]);
spin_unlock(&ioapic->lock);
}
static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
{
int i;
struct kvm_ioapic *ioapic = container_of(work, struct kvm_ioapic,
eoi_inject.work);
spin_lock(&ioapic->lock);
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
if (ent->fields.trig_mode != IOAPIC_LEVEL_TRIG)
continue;
if (ioapic->irr & (1 << i) && !ent->fields.remote_irr)
ioapic_service(ioapic, i, false);
}
spin_unlock(&ioapic->lock);
}
#define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
struct kvm_ioapic *ioapic, int vector, int trigger_mode)
{
int i;
for (i = 0; i < IOAPIC_NUM_PINS; i++) {
union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
if (ent->fields.vector != vector)
continue;
if (i == RTC_GSI)
rtc_irq_eoi(ioapic, vcpu);
/*
* We are dropping lock while calling ack notifiers because ack
* notifier callbacks for assigned devices call into IOAPIC
* recursively. Since remote_irr is cleared only after call
* to notifiers if the same vector will be delivered while lock
* is dropped it will be put into irr and will be delivered
* after ack notifier returns.
*/
spin_unlock(&ioapic->lock);
kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
spin_lock(&ioapic->lock);
if (trigger_mode != IOAPIC_LEVEL_TRIG)
continue;
ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
ent->fields.remote_irr = 0;
if (!ent->fields.mask && (ioapic->irr & (1 << i))) {
++ioapic->irq_eoi[i];
if (ioapic->irq_eoi[i] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
/*
* Real hardware does not deliver the interrupt
* immediately during eoi broadcast, and this
* lets a buggy guest make slow progress
* even if it does not correctly handle a
* level-triggered interrupt. Emulate this
* behavior if we detect an interrupt storm.
*/
schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
ioapic->irq_eoi[i] = 0;
trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
} else {
ioapic_service(ioapic, i, false);
}
} else {
ioapic->irq_eoi[i] = 0;
}
}
}
bool kvm_ioapic_handles_vector(struct kvm *kvm, int vector)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
smp_rmb();
return test_bit(vector, ioapic->handled_vectors);
}
void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
{
struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
spin_lock(&ioapic->lock);
__kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode);
spin_unlock(&ioapic->lock);
}
static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
{
return container_of(dev, struct kvm_ioapic, dev);
}
static inline int ioapic_in_range(struct kvm_ioapic *ioapic, gpa_t addr)
{
return ((addr >= ioapic->base_address &&
(addr < ioapic->base_address + IOAPIC_MEM_LENGTH)));
}
static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
void *val)
{
struct kvm_ioapic *ioapic = to_ioapic(this);
u32 result;
if (!ioapic_in_range(ioapic, addr))
return -EOPNOTSUPP;
ioapic_debug("addr %lx\n", (unsigned long)addr);
ASSERT(!(addr & 0xf)); /* check alignment */
addr &= 0xff;
spin_lock(&ioapic->lock);
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;
}
spin_unlock(&ioapic->lock);
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);
}
return 0;
}
static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
const void *val)
{
struct kvm_ioapic *ioapic = to_ioapic(this);
u32 data;
if (!ioapic_in_range(ioapic, addr))
return -EOPNOTSUPP;
ioapic_debug("ioapic_mmio_write addr=%p len=%d val=%p\n",
(void*)addr, len, val);
ASSERT(!(addr & 0xf)); /* check alignment */
switch (len) {
case 8:
case 4:
data = *(u32 *) val;
break;
case 2:
data = *(u16 *) val;
break;
case 1:
data = *(u8 *) val;
break;
default:
printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
return 0;
}
addr &= 0xff;
spin_lock(&ioapic->lock);
switch (addr) {
case IOAPIC_REG_SELECT:
ioapic->ioregsel = data & 0xFF; /* 8-bit register */
break;
case IOAPIC_REG_WINDOW:
ioapic_write_indirect(ioapic, data);
break;
default:
break;
}
spin_unlock(&ioapic->lock);
return 0;
}
static void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
{
int i;
cancel_delayed_work_sync(&ioapic->eoi_inject);
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;
memset(ioapic->irq_eoi, 0x00, IOAPIC_NUM_PINS);
rtc_irq_eoi_tracking_reset(ioapic);
update_handled_vectors(ioapic);
}
static const struct kvm_io_device_ops ioapic_mmio_ops = {
.read = ioapic_mmio_read,
.write = ioapic_mmio_write,
};
int kvm_ioapic_init(struct kvm *kvm)
{
struct kvm_ioapic *ioapic;
int ret;
ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
if (!ioapic)
return -ENOMEM;
spin_lock_init(&ioapic->lock);
INIT_DELAYED_WORK(&ioapic->eoi_inject, kvm_ioapic_eoi_inject_work);
kvm->arch.vioapic = ioapic;
kvm_ioapic_reset(ioapic);
kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
ioapic->kvm = kvm;
mutex_lock(&kvm->slots_lock);
ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, ioapic->base_address,
IOAPIC_MEM_LENGTH, &ioapic->dev);
mutex_unlock(&kvm->slots_lock);
if (ret < 0) {
kvm->arch.vioapic = NULL;
kfree(ioapic);
}
return ret;
}
void kvm_ioapic_destroy(struct kvm *kvm)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
cancel_delayed_work_sync(&ioapic->eoi_inject);
if (ioapic) {
kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &ioapic->dev);
kvm->arch.vioapic = NULL;
kfree(ioapic);
}
}
int kvm_get_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
{
struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
if (!ioapic)
return -EINVAL;
spin_lock(&ioapic->lock);
memcpy(state, ioapic, sizeof(struct kvm_ioapic_state));
spin_unlock(&ioapic->lock);
return 0;
}
int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
{
struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
if (!ioapic)
return -EINVAL;
spin_lock(&ioapic->lock);
memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
ioapic->irr = 0;
update_handled_vectors(ioapic);
kvm_vcpu_request_scan_ioapic(kvm);
kvm_ioapic_inject_all(ioapic, state->irr);
spin_unlock(&ioapic->lock);
return 0;
}