Patent ID: 8028184
Filing Date: 2011-09-27
Classification: G06F

Abstract:
1. In a computer system comprising a guest operating system (OS), at least one physical device, and a virtual machine monitor (VMM) which emulates the physical device as a logical device and switches the access target of the OS between the physical device and the logical device, a method comprising steps of: transmitting a virtual suspend instruction for temporarily suspending the execution of the OS from the VMM to the OS; after receiving notification that the OS completed the suspension of the execution, the VMM executing an access target changing process for switching the access target of the OS between the physical device and the logical device; when switching the access target of the OS from the physical device to the logical device, the VMM allowing the OS to access the logical device; and when switching the access target of the OS from the logical device to the physical device, the VMM allowing the OS to directly access the physical device corresponding to the logical device.