Device, system, and method for inspecting direct memory access requests

A method at an inspection unit, the method comprising:

• receiving first messages from an input-output memory management unit (IOMMU), wherein the first messages each indicate a completion of a respective address translation, and wherein the inspection unit is coupled between the IOMMU and a first endpoint device;
• creating entries in a registry of accessible addresses based on the first messages, the entries each indicating an accessibility of a respective address by a respective endpoint device;
• receiving a direct memory access (DMA) request from the first endpoint device;
• performing an address search of the registry based on the DMA request;
• and
• selectively signaling, based on the address search, whether an operation with the DMA request is to be performed.

A system comprising

• a memory;
• an input-output memory management unit (IOMMU);
• a first endpoint device coupled to the memory via the IOMMU;
• an inspection unit coupled between the IOMMU and the first endpoint device, the inspection unit comprising:
• manager circuitry to create entries of a registry of accessible addresses, the entries each based on a respective one of first messages received via the first hardware interface, wherein the first messages each indicate a completion of a respective address translation, the entries each to indicate an accessibility of a respective address by a respective endpoint device of one or more endpoint devices including the first endpoint device;
• and
• controller circuitry coupled to the manager circuitry, the controller circuitry to receive a direct memory access (DMA) request from the first endpoint device, to signal the manager circuitry to perform an address search of the registry based on the DMA request, and to selectively signal, based on the address search, whether an operation with the DMA request is to be performed.