Apparatus for translating virtual address space

PURPOSE: A virtual address space switch device is provided to reduce memory usage and to improve the performance of a virtual machine by not mapping a page table of a VMM(Virtual Machine Monitor) with a virtual address space of a guest OS. CONSTITUTION: A guest OS(131) is executed in a virtual address space of the guest OS, and a VMM(120) is executed in a virtual address space of the VMM. A gateway page is allocated to a set area of an actual memory area and mapped with the virtual address spaces of the guest OS and the VMM. A memory management unit switches the virtual address spaces of the guest OS and the VMM by mapping a kernel area of the guest OS with a set area of the virtual address space of the VMM. [Reference numerals] (110) Hardware; (120) Virtual machine monitor(VMM); (130) Virtual machine(VM); (131) Guest operating system; (AA) Memory management unit; (BB) Memory