International Business Machines Corporation
Context tracking for multiple virtualization layers in a virtually tagged cache

Abstract:

A system of handling electronic information having a virtually tagged cache having a directory and a plurality of entries containing data, the directory containing multiple entries, each entry configured to comprise at least a virtual address and one of a plurality of context tags, wherein each context tag is an encoding for one of a plurality of layers of address space; a context tag table having a plurality of entries, each entry configured to map one of the plurality of context tags to one of the plurality of layers of space; and a scratch register containing a current context tag for a current layer of address space on which the processor is operating. The virtually tagged cache is configured to preserve information in the virtually tagged cache when performing a context switch in the system.