* KVM: protect assigned dev workqueue, int handler and irq acker
@ 2009-02-26 23:50 Marcelo Tosatti
2009-02-27 4:17 ` Yang, Sheng
0 siblings, 1 reply; 4+ messages in thread
From: Marcelo Tosatti @ 2009-02-26 23:50 UTC (permalink / raw)
To: kvm; +Cc: Avi Kivity, Yang, Sheng, Chris Wright
Can someone with HW test this please?
-----
kvm_assigned_dev_ack_irq is vulnerable to a race condition with the
interrupt handler function. It does:
if (dev->host_irq_disabled) {
enable_irq(dev->host_irq);
dev->host_irq_disabled = false;
}
If an interrupt triggers before the host->dev_irq_disabled assignment,
it will disable the interrupt and set dev->host_irq_disabled to true.
On return to kvm_assigned_dev_ack_irq, dev->host_irq_disabled is set to
false, and the next kvm_assigned_dev_ack_irq call will fail to reenable
it.
Other than that, having the interrupt handler and work handlers run in
parallel sounds like asking for trouble (could not spot any obvious
problem, but better not have to, its fragile).
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 3832243..faaf386 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -152,6 +152,7 @@ struct kvm {
unsigned long mmu_notifier_seq;
long mmu_notifier_count;
#endif
+ spinlock_t assigned_dev_lock;
};
/* The guest did something we don't support. */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4d2be16..2bbf074 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -41,6 +41,7 @@
#include <linux/pagemap.h>
#include <linux/mman.h>
#include <linux/swap.h>
+#include <linux/spinlock.h>
#include <asm/processor.h>
#include <asm/io.h>
@@ -132,6 +133,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
* finer-grained lock, update this
*/
mutex_lock(&kvm->lock);
+ spin_lock_irq(&kvm->assigned_dev_lock);
if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_MSIX) {
struct kvm_guest_msix_entry *guest_entries =
assigned_dev->guest_msix_entries;
@@ -158,18 +160,21 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
}
}
+ spin_unlock_irq(&kvm->assigned_dev_lock);
mutex_unlock(&assigned_dev->kvm->lock);
}
static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
{
+ unsigned long flags;
struct kvm_assigned_dev_kernel *assigned_dev =
(struct kvm_assigned_dev_kernel *) dev_id;
+ spin_lock_irqsave(&assigned_dev->kvm->assigned_dev_lock, flags);
if (assigned_dev->irq_requested_type == KVM_ASSIGNED_DEV_MSIX) {
int index = find_index_from_host_irq(assigned_dev, irq);
if (index < 0)
- return IRQ_HANDLED;
+ goto out;
assigned_dev->guest_msix_entries[index].flags |=
KVM_ASSIGNED_MSIX_PENDING;
}
@@ -179,6 +184,8 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
disable_irq_nosync(irq);
assigned_dev->host_irq_disabled = true;
+out:
+ spin_unlock_irqrestore(&assigned_dev->kvm->assigned_dev_lock, flags);
return IRQ_HANDLED;
}
@@ -186,6 +193,7 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
{
struct kvm_assigned_dev_kernel *dev;
+ unsigned long flags;
if (kian->gsi == -1)
return;
@@ -198,10 +206,12 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
/* The guest irq may be shared so this ack may be
* from another device.
*/
+ spin_lock_irqsave(&dev->kvm->assigned_dev_lock, flags);
if (dev->host_irq_disabled) {
enable_irq(dev->host_irq);
dev->host_irq_disabled = false;
}
+ spin_unlock_irqrestore(&dev->kvm->assigned_dev_lock, flags);
}
/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
@@ -955,6 +965,7 @@ static struct kvm *kvm_create_vm(void)
kvm->mm = current->mm;
atomic_inc(&kvm->mm->mm_count);
spin_lock_init(&kvm->mmu_lock);
+ spin_lock_init(&kvm->assigned_dev_lock);
kvm_io_bus_init(&kvm->pio_bus);
mutex_init(&kvm->lock);
kvm_io_bus_init(&kvm->mmio_bus);
----- End forwarded message -----
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: KVM: protect assigned dev workqueue, int handler and irq acker
2009-02-26 23:50 KVM: protect assigned dev workqueue, int handler and irq acker Marcelo Tosatti
@ 2009-02-27 4:17 ` Yang, Sheng
2009-02-27 17:54 ` Marcelo Tosatti
0 siblings, 1 reply; 4+ messages in thread
From: Yang, Sheng @ 2009-02-27 4:17 UTC (permalink / raw)
To: Marcelo Tosatti; +Cc: kvm, Avi Kivity, Chris Wright
On Friday 27 February 2009 07:50:54 Marcelo Tosatti wrote:
> Can someone with HW test this please?
Good catch! The patch works fine on my side.
Can it be a per-device lock? One big lock for all assigned device seems
restrict scalability.
> -----
>
> kvm_assigned_dev_ack_irq is vulnerable to a race condition with the
> interrupt handler function. It does:
>
> if (dev->host_irq_disabled) {
> enable_irq(dev->host_irq);
> dev->host_irq_disabled = false;
> }
>
> If an interrupt triggers before the host->dev_irq_disabled assignment,
> it will disable the interrupt and set dev->host_irq_disabled to true.
>
> On return to kvm_assigned_dev_ack_irq, dev->host_irq_disabled is set to
> false, and the next kvm_assigned_dev_ack_irq call will fail to reenable
> it.
>
> Other than that, having the interrupt handler and work handlers run in
> parallel sounds like asking for trouble (could not spot any obvious
> problem, but better not have to, its fragile).
Well, my original purpose is a FIFO between interrupt handler and work(for
MSI-X), but seems too complex... And I also don't see any problem for now...
--
regards
Yang, Sheng
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 3832243..faaf386 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -152,6 +152,7 @@ struct kvm {
> unsigned long mmu_notifier_seq;
> long mmu_notifier_count;
> #endif
> + spinlock_t assigned_dev_lock;
> };
>
> /* The guest did something we don't support. */
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 4d2be16..2bbf074 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -41,6 +41,7 @@
> #include <linux/pagemap.h>
> #include <linux/mman.h>
> #include <linux/swap.h>
> +#include <linux/spinlock.h>
>
> #include <asm/processor.h>
> #include <asm/io.h>
> @@ -132,6 +133,7 @@ static void
> kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) *
> finer-grained lock, update this
> */
> mutex_lock(&kvm->lock);
> + spin_lock_irq(&kvm->assigned_dev_lock);
> if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_MSIX) {
> struct kvm_guest_msix_entry *guest_entries =
> assigned_dev->guest_msix_entries;
> @@ -158,18 +160,21 @@ static void
> kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) }
> }
>
> + spin_unlock_irq(&kvm->assigned_dev_lock);
> mutex_unlock(&assigned_dev->kvm->lock);
> }
>
> static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
> {
> + unsigned long flags;
> struct kvm_assigned_dev_kernel *assigned_dev =
> (struct kvm_assigned_dev_kernel *) dev_id;
>
> + spin_lock_irqsave(&assigned_dev->kvm->assigned_dev_lock, flags);
> if (assigned_dev->irq_requested_type == KVM_ASSIGNED_DEV_MSIX) {
> int index = find_index_from_host_irq(assigned_dev, irq);
> if (index < 0)
> - return IRQ_HANDLED;
> + goto out;
> assigned_dev->guest_msix_entries[index].flags |=
> KVM_ASSIGNED_MSIX_PENDING;
> }
> @@ -179,6 +184,8 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void
> *dev_id) disable_irq_nosync(irq);
> assigned_dev->host_irq_disabled = true;
>
> +out:
> + spin_unlock_irqrestore(&assigned_dev->kvm->assigned_dev_lock, flags);
> return IRQ_HANDLED;
> }
>
> @@ -186,6 +193,7 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void
> *dev_id) static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier
> *kian) {
> struct kvm_assigned_dev_kernel *dev;
> + unsigned long flags;
>
> if (kian->gsi == -1)
> return;
> @@ -198,10 +206,12 @@ static void kvm_assigned_dev_ack_irq(struct
> kvm_irq_ack_notifier *kian) /* The guest irq may be shared so this ack may
> be
> * from another device.
> */
> + spin_lock_irqsave(&dev->kvm->assigned_dev_lock, flags);
> if (dev->host_irq_disabled) {
> enable_irq(dev->host_irq);
> dev->host_irq_disabled = false;
> }
> + spin_unlock_irqrestore(&dev->kvm->assigned_dev_lock, flags);
> }
>
> /* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
> @@ -955,6 +965,7 @@ static struct kvm *kvm_create_vm(void)
> kvm->mm = current->mm;
> atomic_inc(&kvm->mm->mm_count);
> spin_lock_init(&kvm->mmu_lock);
> + spin_lock_init(&kvm->assigned_dev_lock);
> kvm_io_bus_init(&kvm->pio_bus);
> mutex_init(&kvm->lock);
> kvm_io_bus_init(&kvm->mmio_bus);
>
>
> ----- End forwarded message -----
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: KVM: protect assigned dev workqueue, int handler and irq acker
2009-02-27 4:17 ` Yang, Sheng
@ 2009-02-27 17:54 ` Marcelo Tosatti
2009-03-02 7:01 ` Yang, Sheng
0 siblings, 1 reply; 4+ messages in thread
From: Marcelo Tosatti @ 2009-02-27 17:54 UTC (permalink / raw)
To: Yang, Sheng; +Cc: kvm, Avi Kivity, Chris Wright
On Fri, Feb 27, 2009 at 12:17:01PM +0800, Yang, Sheng wrote:
> On Friday 27 February 2009 07:50:54 Marcelo Tosatti wrote:
> > Can someone with HW test this please?
>
> Good catch! The patch works fine on my side.
>
> Can it be a per-device lock? One big lock for all assigned device seems
> restrict scalability.
Since all state is per-device, yes.
Can you please review, test and ack the patch below?
Thanks.
> > -----
> >
> > kvm_assigned_dev_ack_irq is vulnerable to a race condition with the
> > interrupt handler function. It does:
> >
> > if (dev->host_irq_disabled) {
> > enable_irq(dev->host_irq);
> > dev->host_irq_disabled = false;
> > }
> >
> > If an interrupt triggers before the host->dev_irq_disabled assignment,
> > it will disable the interrupt and set dev->host_irq_disabled to true.
> >
> > On return to kvm_assigned_dev_ack_irq, dev->host_irq_disabled is set to
> > false, and the next kvm_assigned_dev_ack_irq call will fail to reenable
> > it.
> >
> > Other than that, having the interrupt handler and work handlers run in
> > parallel sounds like asking for trouble (could not spot any obvious
> > problem, but better not have to, its fragile).
>
> Well, my original purpose is a FIFO between interrupt handler and work(for
> MSI-X), but seems too complex... And I also don't see any problem for now...
>
> --
> regards
> Yang, Sheng
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 3832243..16bf60b 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -349,6 +349,7 @@ struct kvm_assigned_dev_kernel {
int flags;
struct pci_dev *dev;
struct kvm *kvm;
+ spinlock_t assigned_dev_lock;
};
struct kvm_irq_mask_notifier {
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4d2be16..b7d060f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -41,6 +41,7 @@
#include <linux/pagemap.h>
#include <linux/mman.h>
#include <linux/swap.h>
+#include <linux/spinlock.h>
#include <asm/processor.h>
#include <asm/io.h>
@@ -132,6 +133,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
* finer-grained lock, update this
*/
mutex_lock(&kvm->lock);
+ spin_lock_irq(&assigned_dev->assigned_dev_lock);
if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_MSIX) {
struct kvm_guest_msix_entry *guest_entries =
assigned_dev->guest_msix_entries;
@@ -158,18 +160,21 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
}
}
+ spin_unlock_irq(&assigned_dev->assigned_dev_lock);
mutex_unlock(&assigned_dev->kvm->lock);
}
static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
{
+ unsigned long flags;
struct kvm_assigned_dev_kernel *assigned_dev =
(struct kvm_assigned_dev_kernel *) dev_id;
+ spin_lock_irqsave(&assigned_dev->assigned_dev_lock, flags);
if (assigned_dev->irq_requested_type == KVM_ASSIGNED_DEV_MSIX) {
int index = find_index_from_host_irq(assigned_dev, irq);
if (index < 0)
- return IRQ_HANDLED;
+ goto out;
assigned_dev->guest_msix_entries[index].flags |=
KVM_ASSIGNED_MSIX_PENDING;
}
@@ -179,6 +184,8 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
disable_irq_nosync(irq);
assigned_dev->host_irq_disabled = true;
+out:
+ spin_unlock_irqrestore(&assigned_dev->assigned_dev_lock, flags);
return IRQ_HANDLED;
}
@@ -186,6 +193,7 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
{
struct kvm_assigned_dev_kernel *dev;
+ unsigned long flags;
if (kian->gsi == -1)
return;
@@ -198,10 +206,12 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
/* The guest irq may be shared so this ack may be
* from another device.
*/
+ spin_lock_irqsave(&dev->assigned_dev_lock, flags);
if (dev->host_irq_disabled) {
enable_irq(dev->host_irq);
dev->host_irq_disabled = false;
}
+ spin_unlock_irqrestore(&dev->assigned_dev_lock, flags);
}
/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
@@ -604,6 +614,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
match->dev = dev;
match->irq_source_id = -1;
match->kvm = kvm;
+ spin_lock_init(&match->assigned_dev_lock);
list_add(&match->list, &kvm->arch.assigned_dev_head);
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: KVM: protect assigned dev workqueue, int handler and irq acker
2009-02-27 17:54 ` Marcelo Tosatti
@ 2009-03-02 7:01 ` Yang, Sheng
0 siblings, 0 replies; 4+ messages in thread
From: Yang, Sheng @ 2009-03-02 7:01 UTC (permalink / raw)
To: Marcelo Tosatti; +Cc: kvm, Avi Kivity, Chris Wright
On Saturday 28 February 2009 01:54:31 Marcelo Tosatti wrote:
> On Fri, Feb 27, 2009 at 12:17:01PM +0800, Yang, Sheng wrote:
> > On Friday 27 February 2009 07:50:54 Marcelo Tosatti wrote:
> > > Can someone with HW test this please?
> >
> > Good catch! The patch works fine on my side.
> >
> > Can it be a per-device lock? One big lock for all assigned device seems
> > restrict scalability.
>
> Since all state is per-device, yes.
>
> Can you please review, test and ack the patch below?
I just checked dmesg and got this...
[ 1105.343824] ------------[ cut here ]------------
[ 1105.347814] WARNING: at kernel/smp.c:226
smp_call_function_single+0x41/0x10b()
[ 1105.347814] Hardware name: To Be Filled By O.E.M.
[ 1105.347814] Modules linked in: kvm_intel kvm bridge stp llc i2c_dev
i2c_core e1000 e1000e ehci_hcd ohci_hcd uhci_hcd
[ 1105.347814] Pid: 9, comm: events/0 Tainted: G W 2.6.29-rc4-00001-
gd5b5623 #20
[ 1105.347814] Call Trace:
[ 1105.347814] [<ffffffff80239ddc>] warn_slowpath+0xd3/0xf2
[ 1105.347814] [<ffffffff8022ec6d>] ? __enqueue_entity+0x74/0x76
[ 1105.347814] [<ffffffff8022ed1c>] ? enqueue_entity+0xad/0xb6
[ 1105.347814] [<ffffffff80232771>] ? try_to_wake_up+0x1ff/0x211
[ 1105.347814] [<ffffffff80260061>] smp_call_function_single+0x41/0x10b
[ 1105.347814] [<ffffffffa0089bc5>] kvm_vcpu_kick+0x74/0x7c [kvm]
[ 1105.347814] [<ffffffffa009c559>] kvm_apic_set_irq+0x70/0x77 [kvm]
[ 1105.347814] [<ffffffffa009dfa8>] kvm_set_msi+0xe8/0x10d [kvm]
[ 1105.347814] [<ffffffffa00869b6>] ?
kvm_assigned_dev_interrupt_work_handler+0x30/0xfd [kvm]
[ 1105.347814] [<ffffffffa009e0a4>] kvm_set_irq+0x6f/0xb3 [kvm]
[ 1105.347814] [<ffffffffa0086a02>]
kvm_assigned_dev_interrupt_work_handler+0x7c/0xfd [kvm]
[ 1105.347814] [<ffffffffa0086986>] ?
kvm_assigned_dev_interrupt_work_handler+0x0/0xfd [kvm]
[ 1105.347814] [<ffffffff802497ac>] run_workqueue+0xf5/0x1fd
[ 1105.347814] [<ffffffff80249756>] ? run_workqueue+0x9f/0x1fd
[ 1105.347814] [<ffffffff8024a49e>] worker_thread+0xdb/0xe8
[ 1105.347814] [<ffffffff8024d342>] ? autoremove_wake_function+0x0/0x38
[ 1105.347814] [<ffffffff8024a3c3>] ? worker_thread+0x0/0xe8
[ 1105.347814] [<ffffffff8024d231>] kthread+0x49/0x78
[ 1105.347814] [<ffffffff8020c53a>] child_rip+0xa/0x20
[ 1105.347814] [<ffffffff8020bf3c>] ? restore_args+0x0/0x30
[ 1105.347814] [<ffffffff802342c2>] ? finish_task_switch+0x0/0xf3
[ 1105.347814] [<ffffffff8024d1e8>] ? kthread+0x0/0x78
[ 1105.347814] [<ffffffff8020c530>] ? child_rip+0x0/0x20
[ 1105.347814] ---[ end trace 3b3fe301343db608 ]---
--
regards
Yang, Sheng
> Thanks.
>
> > > -----
> > >
> > > kvm_assigned_dev_ack_irq is vulnerable to a race condition with the
> > > interrupt handler function. It does:
> > >
> > > if (dev->host_irq_disabled) {
> > > enable_irq(dev->host_irq);
> > > dev->host_irq_disabled = false;
> > > }
> > >
> > > If an interrupt triggers before the host->dev_irq_disabled assignment,
> > > it will disable the interrupt and set dev->host_irq_disabled to true.
> > >
> > > On return to kvm_assigned_dev_ack_irq, dev->host_irq_disabled is set to
> > > false, and the next kvm_assigned_dev_ack_irq call will fail to reenable
> > > it.
> > >
> > > Other than that, having the interrupt handler and work handlers run in
> > > parallel sounds like asking for trouble (could not spot any obvious
> > > problem, but better not have to, its fragile).
> >
> > Well, my original purpose is a FIFO between interrupt handler and
> > work(for MSI-X), but seems too complex... And I also don't see any
> > problem for now...
> >
> > --
> > regards
> > Yang, Sheng
>
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 3832243..16bf60b 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -349,6 +349,7 @@ struct kvm_assigned_dev_kernel {
> int flags;
> struct pci_dev *dev;
> struct kvm *kvm;
> + spinlock_t assigned_dev_lock;
> };
>
> struct kvm_irq_mask_notifier {
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 4d2be16..b7d060f 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -41,6 +41,7 @@
> #include <linux/pagemap.h>
> #include <linux/mman.h>
> #include <linux/swap.h>
> +#include <linux/spinlock.h>
>
> #include <asm/processor.h>
> #include <asm/io.h>
> @@ -132,6 +133,7 @@ static void
> kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) *
> finer-grained lock, update this
> */
> mutex_lock(&kvm->lock);
> + spin_lock_irq(&assigned_dev->assigned_dev_lock);
> if (assigned_dev->irq_requested_type & KVM_ASSIGNED_DEV_MSIX) {
> struct kvm_guest_msix_entry *guest_entries =
> assigned_dev->guest_msix_entries;
> @@ -158,18 +160,21 @@ static void
> kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) }
> }
>
> + spin_unlock_irq(&assigned_dev->assigned_dev_lock);
> mutex_unlock(&assigned_dev->kvm->lock);
> }
>
> static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
> {
> + unsigned long flags;
> struct kvm_assigned_dev_kernel *assigned_dev =
> (struct kvm_assigned_dev_kernel *) dev_id;
>
> + spin_lock_irqsave(&assigned_dev->assigned_dev_lock, flags);
> if (assigned_dev->irq_requested_type == KVM_ASSIGNED_DEV_MSIX) {
> int index = find_index_from_host_irq(assigned_dev, irq);
> if (index < 0)
> - return IRQ_HANDLED;
> + goto out;
> assigned_dev->guest_msix_entries[index].flags |=
> KVM_ASSIGNED_MSIX_PENDING;
> }
> @@ -179,6 +184,8 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void
> *dev_id) disable_irq_nosync(irq);
> assigned_dev->host_irq_disabled = true;
>
> +out:
> + spin_unlock_irqrestore(&assigned_dev->assigned_dev_lock, flags);
> return IRQ_HANDLED;
> }
>
> @@ -186,6 +193,7 @@ static irqreturn_t kvm_assigned_dev_intr(int irq, void
> *dev_id) static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier
> *kian) {
> struct kvm_assigned_dev_kernel *dev;
> + unsigned long flags;
>
> if (kian->gsi == -1)
> return;
> @@ -198,10 +206,12 @@ static void kvm_assigned_dev_ack_irq(struct
> kvm_irq_ack_notifier *kian) /* The guest irq may be shared so this ack may
> be
> * from another device.
> */
> + spin_lock_irqsave(&dev->assigned_dev_lock, flags);
> if (dev->host_irq_disabled) {
> enable_irq(dev->host_irq);
> dev->host_irq_disabled = false;
> }
> + spin_unlock_irqrestore(&dev->assigned_dev_lock, flags);
> }
>
> /* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
> @@ -604,6 +614,7 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
> match->dev = dev;
> match->irq_source_id = -1;
> match->kvm = kvm;
> + spin_lock_init(&match->assigned_dev_lock);
>
> list_add(&match->list, &kvm->arch.assigned_dev_head);
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2009-03-02 7:01 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-02-26 23:50 KVM: protect assigned dev workqueue, int handler and irq acker Marcelo Tosatti
2009-02-27 4:17 ` Yang, Sheng
2009-02-27 17:54 ` Marcelo Tosatti
2009-03-02 7:01 ` Yang, Sheng
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