Patent ID: 9317444
Filing Date: 2016-04-19
CPC Classification: G06F

Claim Text:
1. A method to perform direct memory access (DMA) operations, the method comprising: initializing a ring of descriptors, the descriptors to index respective buffers for storing, in a first memory, data to be transmitted by an output device; and causing prefetching of a first address translation for a second descriptor in the ring of descriptors to be performed after a first DMA operation is performed to retrieve, for transmission by the output device, first data from a first buffer indexed by a first descriptor in the ring of descriptors, and before second data that is to be retrieved, for transmission by the output device, from a second buffer indexed by the second descriptor is determined to be ready for transmission by the output device, the first address translation being associated with a second DMA operation for retrieving the second data from the second buffer indexed by the second descriptor, wherein the second descriptor is a next descriptor in the ring of descriptors relative to the first descriptor, the first address translation is for translating a guest physical address of the second descriptor to a host physical address of the second descriptor, and causing prefetching of the first address translation to be performed comprises initiating a third DMA operation to retrieve the second descriptor from the ring of descriptors, the third DMA operation to cause the first address translation to be prefetched and cached before the second data is determined to be ready for transmission and before the second DMA operation is to be performed.