US Patent 10489302 Emulated translation unit using a management processor

An emulated input/output memory management unit (IOMMU) includes a management processor to perform page table translation in software. The emulated IOMMU can also include a hardware input/output translation lookaside buffer (IOTLB) to store translations between virtual addresses and physical memory addresses. When a translation from a virtual address to a physical address is not found in the IOTLB for an I/O request, the translation can be generated by the management processor using page tables from a memory and can be stored in the IOTLB. Some embodiments can be used to emulate interrupt translation service for message based interrupts for an interrupt controller.