Virtualization system using hardware assistance for shadow page table coherence

TLDR: In this article, the authors present a method for maintaining a shadow page table in at least partial correspondence with guest page mappings of a guest computation, marking with a traced write indication at least those entries of the shadow page tables that map physical memory locations which themselves encode the guest page mapping.

Abstract: One embodiment of the present invention includes a method for maintaining a shadow page table in at least partial correspondence with guest page mappings of a guest computation. The method marking with a traced write indication at least those entries of the shadow page table that map physical memory locations which themselves encode the guest page mappings, the marking identifying, for a hardware facility, a subset of memory access targets for which updates are to be recorded in a guest write buffer accessible to the virtualization system. Responsive to a coherency-inducing operation of the guest computation, the method reads from the guest write buffer and introduces corresponding updates into the shadow page table.