Patent ID: 8719817

Claim:
A method of direct access by a virtual machine (VM) running on a host machine to physical storage via a virtual function (VF) running on an input/output (IO) adapter comprising: storing by a virtualization intermediary an indication of an active path associated with a virtual storage device to a memory region shared by a guest driver and the virtualization intermediary, wherein the guest driver runs in a first memory space region of a first context and the virtualization intermediary runs in a second memory space region of a second context, and wherein the first memory space region and the second memory space region are different memory space regions except for the shared memory region; obtaining by the guest driver the stored indication of the active path from the shared memory region without changing the first context of the guest driver running in the first memory space region to the second context of the virtualization intermediary running in the second memory space region; dispatching an IO request by the guest driver directly to the VF that includes the indication of the active path without intervention from the virtualization intermediary; and sending by the VF the IO request that includes the indicated active path.