Accessing copy information of MMIO register by guest OS in both active and inactive state of a designated logical processor corresponding to the guest OS

摘要

A method and an apparatus for storing a copy of memory-mapped I/O (MMIO) register are provided for enhancing data processing efficiency. In a structure in which data processing is executed by associating a plurality of logical processors with a physical processor by timing sharing, a host OS stores copy information, namely, shadow, of the MMIO register corresponding to a logical processor in memory both in an active state where a physical processor is allocated to a logical processor corresponding to a guest OS and in an inactive state where no physical processor is allocated to a logical processor. This structure enables a guest OS to gain faster access to the MMIO register through the shadow by memory access, instead of a direct access to the MMIO register, so as to achieve efficient data processing.