Patent ID: 7945436
Filing Date: 2011-05-17
Classification: G06F

Abstract:
1. In a virtualized computer system, a virtual device emulated in software and included in a virtual machine, the virtual device comprising: a logic to provide an emulation mode for accessing a physical Input/Output (I/O) device in a host where the virtual machine is executing, wherein the emulation mode is defined to be used for a first plurality of device operations; a logic to provide a pass-through mode for accessing the physical I/O device, wherein the pass-through mode is defined to be used for a second plurality of device operations different from the first plurality of device operations, each of the second plurality of device operations configured to be handled by the physical device via direct access from the virtual machine to the physical device; and a switching logic to switch between the emulation mode and the pass-through mode based on whether a device operation to be performed by the virtual machine on the virtual device belongs to the first plurality or the second plurality of device operations.