From 547de29e5b1662deb05b5f90917902dc0e9ac182 Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Thu, 7 May 2009 17:55:13 -0300 Subject: KVM: protect assigned dev workqueue, int handler and irq acker 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). CC: sheng.yang@intel.com Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- include/linux/kvm_host.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 16181628419..aacc5449f58 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -345,6 +345,7 @@ struct kvm_assigned_dev_kernel { int flags; struct pci_dev *dev; struct kvm *kvm; + spinlock_t assigned_dev_lock; }; struct kvm_irq_mask_notifier { -- cgit v1.2.3