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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2009-06-04 15:08:24 -0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2009-09-10 08:32:49 +0300 |
| commit | fa40a8214bb9bcae8d49c234c19d8b4a6c1f37ff (patch) | |
| tree | 6449f27072f128a1c39faaaeef1787f754345aaf /virt/kvm/kvm_main.c | |
| parent | 60eead79ad8750f80384cbe48fc44edcc78a0305 (diff) | |
| download | linux-fa40a8214bb9bcae8d49c234c19d8b4a6c1f37ff.tar.bz2 | |
KVM: switch irq injection/acking data structures to irq_lock
Protect irq injection/acking data structures with a separate irq_lock
mutex. This fixes the following deadlock:
CPU A CPU B
kvm_vm_ioctl_deassign_dev_irq()
mutex_lock(&kvm->lock); worker_thread()
-> kvm_deassign_irq() -> kvm_assigned_dev_interrupt_work_handler()
-> deassign_host_irq() mutex_lock(&kvm->lock);
-> cancel_work_sync() [blocked]
[gleb: fix ia64 path]
Reported-by: Alex Williamson <alex.williamson@hp.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt/kvm/kvm_main.c')
| -rw-r--r-- | virt/kvm/kvm_main.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index d47e660fb709..0d481b282448 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -62,6 +62,12 @@ MODULE_AUTHOR("Qumranet"); MODULE_LICENSE("GPL"); +/* + * Ordering of locks: + * + * kvm->lock --> kvm->irq_lock + */ + DEFINE_SPINLOCK(kvm_lock); LIST_HEAD(vm_list); @@ -126,11 +132,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) interrupt_work); kvm = assigned_dev->kvm; - /* This is taken to safely inject irq inside the guest. When - * the interrupt injection (or the ioapic code) uses a - * finer-grained lock, update this - */ - mutex_lock(&kvm->lock); + mutex_lock(&kvm->irq_lock); spin_lock_irq(&assigned_dev->assigned_dev_lock); if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) { struct kvm_guest_msix_entry *guest_entries = @@ -149,7 +151,7 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work) assigned_dev->guest_irq, 1); spin_unlock_irq(&assigned_dev->assigned_dev_lock); - mutex_unlock(&assigned_dev->kvm->lock); + mutex_unlock(&assigned_dev->kvm->irq_lock); } static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id) @@ -207,7 +209,7 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian) static void deassign_guest_irq(struct kvm *kvm, struct kvm_assigned_dev_kernel *assigned_dev) { - kvm_unregister_irq_ack_notifier(&assigned_dev->ack_notifier); + kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier); assigned_dev->ack_notifier.gsi = -1; if (assigned_dev->irq_source_id != -1) |