From: "Justin Terry (VM) via Qemu-devel" <qemu-devel@nongnu.org>

Improves the usage of the InterruptNotification registration by skipping the
additional call to WHvSetVirtualProcessorRegisters if we have already
registered for the window exit.

Signed-off-by: Justin Terry (VM) <juterry@microsoft.com>
Message-Id: <1519665216-1078-9-git-send-email-juterry@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Justin Terry (VM) via Qemu-devel <qemu-devel@nongnu.org>
---
 target/i386/whpx-all.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/target/i386/whpx-all.c b/target/i386/whpx-all.c
index 24387be..940bbe5 100644
--- a/target/i386/whpx-all.c
+++ b/target/i386/whpx-all.c
@@ -756,12 +756,11 @@ static void whpx_vcpu_pre_run(CPUState *cpu)
     }
 
     /* Update the state of the interrupt delivery notification */
-    if (cpu->interrupt_request & CPU_INTERRUPT_HARD) {
+    if (!vcpu->window_registered &&
+        cpu->interrupt_request & CPU_INTERRUPT_HARD) {
         reg_values[reg_count].DeliverabilityNotifications.InterruptNotification
             = 1;
-        if (vcpu->window_registered != 1) {
-            vcpu->window_registered = 1;
-        }
+        vcpu->window_registered = 1;
         reg_names[reg_count] = WHvX64RegisterDeliverabilityNotifications;
         reg_count += 1;
     }
-- 
1.8.3.1