Address translation mechanism for shared memory based inter-domain communication

Abstract

A technique for 'zero copy' transitive communication of data between virtual address domains maintains a translation table hierarchy for each domain. The hierarchy of each domain includes a portion corresponding to every other domain in the system, where the portion for any particular domain begins at the same offset in the virtual address space of every domain. For each domain, there is a source hierarchy used only by the domain itself, which provides read/write access to the addresses in that domain; and a target hierarchy which provides read-only access to that domain, for use only when another domain is the target of IDC from that domain. Only one instance of the target hierarchy of each domain is provided, for all other domains as targets of IDC from that domain. For further space savings the source and target translation table hierarchies can be combined at all but the top hierarchy level.