KVM: Optimize searching for highest IRR

Most of the time IRR is empty, so instead of scanning the whole IRR on
each VM entry keep a variable that tells us if IRR is not empty. IRR
will have to be scanned twice on each IRQ delivery, but this is much
more rare than VM entry.

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

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index a587f8349c46..3f3ecc6edbf5 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -12,6 +12,7 @@ struct kvm_lapic {
         struct kvm_timer lapic_timer;
         u32 divide_count;
         struct kvm_vcpu *vcpu;
+        bool irr_pending;
         struct page *regs_page;
         void *regs;
         gpa_t vapic_addr;