A method and apparatus for cache coherency states is disclosed. In one
embodiment, a cache accessible across two interfaces, an inner interface
and an outer interface, may have a joint cache coherency state. The joint
cache coherency state may have a first state for the inner interface and
a second state for the outer interface, where the second state has higher
privilege than the first state. In one embodiment this may promote
speculative invalidation. In other embodiments this may reduce snoop
transactions on the inner interface.