On Tue, Nov 08, 2022 at 08:50:53AM -0500, Matthew Rosato wrote: > FWIW, vfio-pci via s390 is working fine so far, though I'll put it > through more paces over the next few weeks and report if I find > anything. OK great > As far as mdev drivers... > > -ccw: Sounds like Eric is already aware there is an issue and is investigating (I see errors as well). > > -ap: I see the exact same issue that Christian mentioned... I'll talk to Tony & Jason about it. A clue what is going wrong might get a quick realization on the problem? I'm guessing something in the vfio side more than the access 'pinning' part? > > If I recall there was some desire from the S390 platform team to start > > building on iommufd to create some vIOMMU acceleration for S390 > > guests, this is a necessary first step. > > There's probably something here for -ccw in the future, but you > might be thinking of s390 vfio-pci e.g. to implement the in-kernel > handling of nested mappings on s390 -- yep, work in in progress > here, not ready for sharing yet but I have been most recently basing > my work on top of the nesting series > https://github.com/yiliu1765/iommufd/tree/iommufd-v6.0-rc3-nesting The relation is that if vfio-pci wants to do the above then vfio-ccw/ap will have to run on iommufd when used in the same VM as vfio-pci. So we need it to work :) Jason
