KVM: Drop kvm->irq_lock lock from irq injection path

The only thing it protects now is interrupt injection into lapic and
this can work lockless. Even now with kvm->irq_lock in place access
to lapic is not entirely serialized since vcpu access doesn't take
kvm->irq_lock.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 0 insertions, 2 deletions

diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index bb4ebd89b9ff..30f70fd511c4 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -61,10 +61,8 @@ irqfd_inject(struct work_struct *work)
         struct _irqfd *irqfd = container_of(work, struct _irqfd, inject);
         struct kvm *kvm = irqfd->kvm;
 
-        mutex_lock(&kvm->irq_lock);
         kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 1);
         kvm_set_irq(kvm, KVM_USERSPACE_IRQ_SOURCE_ID, irqfd->gsi, 0);
-        mutex_unlock(&kvm->irq_lock);
 }
 
 /*