KVM: Fix guest shared interrupt with in-kernel irqchip

Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Xiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Sheng Yang 2008-10-15 20:15:06 +08:00 committed by Avi Kivity
parent 6ad9f15c94
commit 5550af4df1
9 changed files with 79 additions and 14 deletions

View file

@ -417,6 +417,9 @@ struct kvm_arch {
struct list_head assigned_dev_head;
struct dmar_domain *intel_iommu_domain;
struct hlist_head irq_ack_notifier_list;
unsigned long irq_sources_bitmap;
unsigned long irq_states[KVM_IOAPIC_NUM_PINS];
};
union cpuid3_t {

View file

@ -778,6 +778,9 @@ static void kvm_init_vm(struct kvm *kvm)
kvm_build_io_pmt(kvm);
INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);
}
struct kvm *kvm_arch_create_vm(void)
@ -941,9 +944,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
goto out;
if (irqchip_in_kernel(kvm)) {
mutex_lock(&kvm->lock);
kvm_ioapic_set_irq(kvm->arch.vioapic,
irq_event.irq,
irq_event.level);
kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
irq_event.irq, irq_event.level);
mutex_unlock(&kvm->lock);
r = 0;
}

View file

@ -364,6 +364,9 @@ struct kvm_arch{
struct page *ept_identity_pagetable;
bool ept_identity_pagetable_done;
unsigned long irq_sources_bitmap;
unsigned long irq_states[KVM_IOAPIC_NUM_PINS];
};
struct kvm_vm_stat {

View file

@ -545,6 +545,12 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm)
if (!pit)
return NULL;
mutex_lock(&kvm->lock);
pit->irq_source_id = kvm_request_irq_source_id(kvm);
mutex_unlock(&kvm->lock);
if (pit->irq_source_id < 0)
return NULL;
mutex_init(&pit->pit_state.lock);
mutex_lock(&pit->pit_state.lock);
spin_lock_init(&pit->pit_state.inject_lock);
@ -587,6 +593,7 @@ void kvm_free_pit(struct kvm *kvm)
mutex_lock(&kvm->arch.vpit->pit_state.lock);
timer = &kvm->arch.vpit->pit_state.pit_timer.timer;
hrtimer_cancel(timer);
kvm_free_irq_source_id(kvm, kvm->arch.vpit->irq_source_id);
mutex_unlock(&kvm->arch.vpit->pit_state.lock);
kfree(kvm->arch.vpit);
}
@ -595,8 +602,8 @@ void kvm_free_pit(struct kvm *kvm)
static void __inject_pit_timer_intr(struct kvm *kvm)
{
mutex_lock(&kvm->lock);
kvm_set_irq(kvm, 0, 1);
kvm_set_irq(kvm, 0, 0);
kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 1);
kvm_set_irq(kvm, kvm->arch.vpit->irq_source_id, 0, 0);
mutex_unlock(&kvm->lock);
}

View file

@ -44,6 +44,7 @@ struct kvm_pit {
struct kvm_io_device speaker_dev;
struct kvm *kvm;
struct kvm_kpit_state pit_state;
int irq_source_id;
};
#define KVM_PIT_BASE_ADDRESS 0x40

View file

@ -1742,7 +1742,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
goto out;
if (irqchip_in_kernel(kvm)) {
mutex_lock(&kvm->lock);
kvm_set_irq(kvm, irq_event.irq, irq_event.level);
kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID,
irq_event.irq, irq_event.level);
mutex_unlock(&kvm->lock);
r = 0;
}
@ -4013,6 +4014,9 @@ struct kvm *kvm_arch_create_vm(void)
INIT_LIST_HEAD(&kvm->arch.active_mmu_pages);
INIT_LIST_HEAD(&kvm->arch.assigned_dev_head);
/* Reserve bit 0 of irq_sources_bitmap for userspace irq source */
set_bit(KVM_USERSPACE_IRQ_SOURCE_ID, &kvm->arch.irq_sources_bitmap);
return kvm;
}

View file

@ -37,6 +37,8 @@
#define KVM_REQ_UNHALT 6
#define KVM_REQ_MMU_SYNC 7
#define KVM_USERSPACE_IRQ_SOURCE_ID 0
struct kvm_vcpu;
extern struct kmem_cache *kvm_vcpu_cache;
@ -306,15 +308,18 @@ struct kvm_assigned_dev_kernel {
int host_irq;
int guest_irq;
int irq_requested;
int irq_source_id;
struct pci_dev *dev;
struct kvm *kvm;
};
void kvm_set_irq(struct kvm *kvm, int irq, int level);
void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi);
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
int kvm_request_irq_source_id(struct kvm *kvm);
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
#ifdef CONFIG_DMAR
int kvm_iommu_map_pages(struct kvm *kvm, gfn_t base_gfn,

View file

@ -25,15 +25,23 @@
#include "ioapic.h"
/* This should be called with the kvm->lock mutex held */
void kvm_set_irq(struct kvm *kvm, int irq, int level)
void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
{
unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
/* Logical OR for level trig interrupt */
if (level)
set_bit(irq_source_id, irq_state);
else
clear_bit(irq_source_id, irq_state);
/* Not possible to detect if the guest uses the PIC or the
* IOAPIC. So set the bit in both. The guest will ignore
* writes to the unused one.
*/
kvm_ioapic_set_irq(kvm->arch.vioapic, irq, level);
kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state));
#ifdef CONFIG_X86
kvm_pic_set_irq(pic_irqchip(kvm), irq, level);
kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state));
#endif
}
@ -58,3 +66,31 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
{
hlist_del(&kian->link);
}
/* The caller must hold kvm->lock mutex */
int kvm_request_irq_source_id(struct kvm *kvm)
{
unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
int irq_source_id = find_first_zero_bit(bitmap,
sizeof(kvm->arch.irq_sources_bitmap));
if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
irq_source_id = -EFAULT;
} else
set_bit(irq_source_id, bitmap);
return irq_source_id;
}
void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
{
int i;
if (irq_source_id <= 0 ||
irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
return;
}
for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
}

View file

@ -105,14 +105,12 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
*/
mutex_lock(&assigned_dev->kvm->lock);
kvm_set_irq(assigned_dev->kvm,
assigned_dev->irq_source_id,
assigned_dev->guest_irq, 1);
mutex_unlock(&assigned_dev->kvm->lock);
kvm_put_kvm(assigned_dev->kvm);
}
/* FIXME: Implement the OR logic needed to make shared interrupts on
* this line behave properly
*/
static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
{
struct kvm_assigned_dev_kernel *assigned_dev =
@ -134,7 +132,7 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
dev = container_of(kian, struct kvm_assigned_dev_kernel,
ack_notifier);
kvm_set_irq(dev->kvm, dev->guest_irq, 0);
kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
enable_irq(dev->host_irq);
}
@ -146,6 +144,7 @@ static void kvm_free_assigned_device(struct kvm *kvm,
free_irq(assigned_dev->host_irq, (void *)assigned_dev);
kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);
kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
if (cancel_work_sync(&assigned_dev->interrupt_work))
/* We had pending work. That means we will have to take
@ -215,6 +214,11 @@ static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
match->ack_notifier.gsi = assigned_irq->guest_irq;
match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
kvm_register_irq_ack_notifier(kvm, &match->ack_notifier);
r = kvm_request_irq_source_id(kvm);
if (r < 0)
goto out_release;
else
match->irq_source_id = r;
/* Even though this is PCI, we don't want to use shared
* interrupts. Sharing host devices with guest-assigned devices