KVM: ioapic: clear IRR for edge-triggered interrupts at delivery

This ensures that IRR bits are set in the KVM_GET_IRQCHIP result only if
the interrupt is still sitting in the IOAPIC.  After the next patches, it
avoids spurious reinjection of the interrupt when KVM_SET_IRQCHIP is
called.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index 0b4914147b9d..25e16a6898ed 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -288,6 +288,9 @@ static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status)
         irqe.level = 1;
         irqe.shorthand = 0;
 
+        if (irqe.trig_mode == IOAPIC_EDGE_TRIG)
+                ioapic->irr &= ~(1 << irq);
+
         if (irq == RTC_GSI && line_status) {
                 BUG_ON(ioapic->rtc_status.pending_eoi != 0);
                 ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe,