Patent ID: 8521919

Claim:
An address management method comprising: intercepting a direct memory access (DMA) request submitted by a guest device to access a memory frame on a host device, wherein the DMA request comprises a guest memory address; and translating the guest memory address in the DMA request to a host memory address according to a mapping scheme using the guest memory address as a key to reference a host memory frame in a memory of the host device, wherein the host memory frame is associated with a first reference count indicating number of active DMA requests directed to the host memory frame by one or more guest devices, wherein the host memory frame is associated with a second reference count indicating number of mappings referencing the host memory frame according to said mapping scheme, wherein a memory management unit (MMU) increments the first reference count, in response to intercepting additional DMA request to access the host memory frame, and wherein the MMU increments the second reference count, in response to intercepting DMA requests by additional guest devices to access the same host memory frame.