On 11/7/22 8:09 PM, Jason Gunthorpe wrote: > On Mon, Nov 07, 2022 at 08:48:53PM -0400, Jason Gunthorpe wrote: >> [ >> This has been in linux-next for a little while now, and we've completed >> the syzkaller run. 1300 hours of CPU time have been invested since the >> last report with no improvement in coverage or new detections. syzkaller >> coverage reached 69%(75%), and review of the misses show substantial >> amounts are WARN_ON's and other debugging which are not expected to be >> covered. >> ] >> >> iommufd is the user API to control the IOMMU subsystem as it relates to >> managing IO page tables that point at user space memory. > > [chop cc list] > > s390 mdev maintainers, > > Can I ask your help to test this with the two S390 mdev drivers? Now > that gvt is passing and we've covered alot of the QA ground it is a > good time to run it. > > Take the branch from here: > > https://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd.git/log/?h=for-next > > And build the kernel with > > CONFIG_VFIO_CONTAINER=n > CONFIG_IOMMUFD=y > CONFIG_IOMMUFD_VFIO_CONTAINER=y > > And your existing stuff should work with iommufd providing the iommu > support to vfio. There will be a dmesg confirming this. > > Let me know if there are any problems! 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. 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. > > 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 Matt
