On Tue, Nov 03, 2020 at 09:23:35AM -0400, Jason Gunthorpe wrote: > Userspace needs fine grained control over the composition of the page > table behind the PASID, 1:1 with the mm_struct is only one use case. VFIO already offers an interface for that. It shouldn't be too complicated to expand that for PASID-bound page-tables. > Userspace needs to be able to handle IOMMU faults, apparently Could be implemented by a fault-fd handed out by VFIO. > The Intel guys had a bunch of other stuff too, looking through the new > API they are proposing for vfio gives some flavour what they think is > needed.. I really don't think that user-space should have to deal with details like PASIDs or other IOMMU internals, unless absolutly necessary. This is an OS we work on, and the idea behind an OS is to abstract the hardware away. Regards, Joerg