Translation Data Prefetch in an IOMMU

摘要

In an embodiment, a system memory stores a set of input/output (I/O) translation tables. One or more I/O devices initiate direct memory access (DMA) requests including virtual addresses. An I/O memory management unit (IOMMU) is coupled to the I/O devices and the system memory, wherein the IOMMU is configured to translate the virtual addresses in the DMA requests to physical addresses to access the system memory according to an I/O translation mechanism implemented by the IOMMU. The IOMMU comprises one or more caches, and is configured to read translation data from the I/O translation tables responsive to a prefetch command that specifies a first virtual address. The reads are responsive to the first virtual address and the I/O translation mechanism, and the IOMMU is configured to store data in the caches responsive to the read translation data.