I have come across a guest behavior wherein guest updates the ioapic tables while the interrupt is unmasked. 

 

A condition in hypervisor at the following location:

is preventing the physical ioapic tables from being updated. 

 

The hypervisor is assuming at the above mentioned location that physical ioapic table entries would only be updated if interrupt masking state is changed. Can someone point me to from where does this assumption originates?

 

Thanks, 
Abdul