On Mon, Mar 14, 2022 at 03:44:48PM -0400, Matthew Rosato wrote: > The DTSM, or designation type supported mask, indicates what IOAT formats > are available to the guest. For an interpreted device, userspace will not > know what format(s) the IOAT assist supports, so pass it via the > capability chain. Since the value belongs to the Query PCI Function Group > clp, let's extend the existing capability with a new version. Why is this on the VFIO device? Maybe I don't quite understand it right, but the IOAT is the 'userspace page table'? That is something that should be modeled as a nested iommu domain. Querying the formats and any control logic for this should be on the iommu side not built into VFIO. Jason