Usually I go into these things with a fair amount of skepticism but given the linux kernels usual pace of development and the nature of undisclosed bugs we have

Usually I go into these things with a fair amount of skepticism but given the linux kernels usual pace of development and the nature of undisclosed bugs we have seen in the past this seems like a large hypervisor bug could be the reality. It must be pretty bad if its the kind of bug that they can't really fix easily, and have to push through an entire new feature into something as old and important as the paging code.