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/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index df8bcb0f66d8..8787637b1a9c 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -501,9 +501,7 @@ static void apic_send_ipi(struct kvm_lapic *apic)
                    irq.trig_mode, irq.level, irq.dest_mode, irq.delivery_mode,
                    irq.vector);
 
-        mutex_lock(&apic->vcpu->kvm->irq_lock);
         kvm_irq_delivery_to_apic(apic->vcpu->kvm, apic, &irq);
-        mutex_unlock(&apic->vcpu->kvm->irq_lock);
 }
 
 static u32 apic_get_tmcct(struct kvm_lapic *apic)