by explicitly moving it out of the interrupt shadow. The hypervisor is done
"executing" the HLT and by definition this moves the vcpu out of the
1-instruction interrupt shadow.
Prior to this change the interrupt would be held pending because the VMCS
guest-interruptibility-state would indicate that "blocking by STI" was in
effect. This resulted in an unnecessary round trip into the guest before
the pending interrupt could be injected.
Reviewed by: grehan