KVM: Handle spurious acks for PIT interrupts

Spurious acks can be generated, for example if the PIC is being reset.
Handle those acks gracefully rather than flooding the log with warnings.

Signed-off-by: Avi Kivity <avi@qumranet.com>

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 7d04dd3ef857c7cbdafd3ada2861bd5ff8de7448..c842060c6c04155dfe8fad2b1d6885f1ae287372 100644 (file)
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -228,7 +228,7 @@ void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
                                                 irq_ack_notifier);
        spin_lock(&ps->inject_lock);
        if (atomic_dec_return(&ps->pit_timer.pending) < 0)
-               WARN_ON(1);
+               atomic_inc(&ps->pit_timer.pending);
        ps->irq_ack = 1;
        spin_unlock(&ps->inject_lock);
 }