On Mon, 2008-10-06 at 14:23 +0800, Sheng Yang wrote:
> On Sat, 2008-10-04 at 11:47 +0300, Avi Kivity wrote:
> > Sheng Yang wrote:
> >> Derived from Avi's suggestion, now every call of kvm_set_irq() should offer
> >> a irq_source_id, which is allocated by kvm_allocate_irq_sources(). We based
> >> on irq_source_id to identify irq source and implement logical OR for shared
> >> level interrupts.
> >>
> >> The allocated irq_source_id can be freed by kvm_free_irq_sources().
> >>
> >>
> >> +
> >> + u32 irq_sources_bitmap;
> >> + u32 irq_states[KVM_IOAPIC_NUM_PINS];
> >>
> >
> > You're using the bit manipulation functions on this, which use unsigned
> > long parameters. This will generate unaligned accesses, which will
> > probably annoy ia64 when this code is ported. So it may be better to
> > wast some space and use unsigned longs here.
> >
> > Other than that, looks a nice and clean to me.
> >
> Yes, of course. Thanks for point it out. :)
>
> Update the patch with unsigned long.
>
Oops, miss one harmless point...
Continue updating.
--
From: Sheng Yang <[EMAIL PROTECTED]>
Date: Mon, 6 Oct 2008 14:32:06 +0800
Subject: [PATCH 1/1] KVM: Fix guest shared interrupt with in-kernel irqchip
Derived from Avi's suggestion, now every call of kvm_set_irq() should offer
a irq_source_id, which is allocated by kvm_allocate_irq_sources(). We based
on irq_source_id to identify irq source and implement logical OR for shared
level interrupts.
The allocated irq_source_id can be freed by kvm_free_irq_sources().
Now we support sizeof(unsigned long) different irq sources at most.
Signed-off-by: Sheng Yang <[EMAIL PROTECTED]>
---
arch/x86/kvm/i8254.c | 11 +++++++++--
arch/x86/kvm/i8254.h | 1 +
arch/x86/kvm/irq.c | 42 +++++++++++++++++++++++++++++++++++++++---
arch/x86/kvm/irq.h | 7 ++++++-
arch/x86/kvm/x86.c | 24 ++++++++++++++++++------
include/asm-x86/kvm_host.h | 3 +++
include/linux/kvm_host.h | 1 +
7 files changed, 77 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 6144d3f..da06919 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -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);
}
@@ -598,8 +605,8 @@ static void __inject_pit_timer_intr(struct kvm *kvm)
int i;
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);
/*
diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index e436d49..4178022 100644
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -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
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 8c1b9c5..69d6e40 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -101,14 +101,22 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
}
/* 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 = &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_pic_set_irq(pic_irqchip(kvm), irq, level);
+ kvm_ioapic_set_irq(kvm->arch.vioapic, irq, !!(*irq_state));
+ kvm_pic_set_irq(pic_irqchip(kvm), irq, !!(*irq_state));
}
void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi)
@@ -132,3 +140,31 @@ 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);
+}
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 9f157c9..b1987f5 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -32,6 +32,8 @@
#define PIC_NUM_PINS 16
+#define KVM_USERSPACE_IRQ_SOURCE_ID 0
+
struct kvm;
struct kvm_vcpu;
@@ -85,7 +87,7 @@ static inline int irqchip_in_kernel(struct kvm *kvm)
void kvm_pic_reset(struct kvm_kpic_state *s);
-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);
@@ -103,4 +105,7 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu);
int pit_has_pending_timer(struct kvm_vcpu *vcpu);
int apic_has_pending_timer(struct kvm_vcpu *vcpu);
+int kvm_request_irq_source_id(struct kvm *kvm);
+void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
+
#endif
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 675fcc1..6c3ac18 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -136,14 +136,12 @@ 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 =
@@ -165,7 +163,7 @@ 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);
}
@@ -178,6 +176,8 @@ static void kvm_free_assigned_device(struct kvm *kvm,
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
* care of kvm_put_kvm.
@@ -319,15 +319,23 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
list_add(&match->list, &kvm->arch.assigned_dev_head);
+ r = kvm_request_irq_source_id(kvm);
+ if (r < 0)
+ goto out_list_del;
+ else
+ match->irq_source_id = r;
+
if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
r = kvm_iommu_map_guest(kvm, match);
if (r)
- goto out_list_del;
+ goto out_free_irq_source_id;
}
out:
mutex_unlock(&kvm->lock);
return r;
+out_free_irq_source_id:
+ kvm_free_irq_source_id(kvm, match->irq_source_id);
out_list_del:
list_del(&match->list);
pci_release_regions(dev);
@@ -1993,7 +2001,8 @@ 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;
}
@@ -4313,6 +4322,9 @@ 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 */
+ kvm->arch.irq_sources_bitmap = 1;
+
return kvm;
}
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 53995a8..dfee063 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -365,6 +365,9 @@ 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 {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 73b7c52..61c378c 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -303,6 +303,7 @@ 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;
};
--
1.5.4.5
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