On Mon, Oct 31, 2022 at 06:38:45PM +0800, Yi Liu wrote: > Hi Jason, > > On 2022/10/26 02:17, Jason Gunthorpe wrote: > > This series provides an alternative container layer for VFIO implemented > > using iommufd. This is optional, if CONFIG_IOMMUFD is not set then it will > > not be compiled in. > > > > At this point iommufd can be injected by passing in a iommfd FD to > > VFIO_GROUP_SET_CONTAINER which will use the VFIO compat layer in iommufd > > to obtain the compat IOAS and then connect up all the VFIO drivers as > > appropriate. > > > > This is temporary stopping point, a following series will provide a way to > > directly open a VFIO device FD and directly connect it to IOMMUFD using > > native ioctls that can expose the IOMMUFD features like hwpt, future > > vPASID and dynamic attachment. > > > > This series, in compat mode, has passed all the qemu tests we have > > available, including the test suites for the Intel GVT mdev. Aside from > > the temporary limitation with P2P memory this is belived to be fully > > compatible with VFIO. > > > > This is on github: https://github.com/jgunthorpe/linux/commits/vfio_iommufd > > In our side, we found the gvt-g test failed. Guest i915 driver stuck at > init phase. While with your former version (commit ID > a249441ba6fd9d658f4a1b568453e3a742d12686), gvt-g test is passing. Oh, I didn't realize you grabbed such an older version for this testing.. > noticed there a quite a few change in iommufd/pages.c from last version. > We are internally tracing in the gvt-g side, may also good to have your > attention. syzkaller just ran into this that I was starting to investigate: @@ -1505,7 +1505,7 @@ int iopt_pages_fill_xarray(struct iopt_pages *pages, unsigned long start_index, int rc; pfn_reader_user_init(&user, pages); - user.upages_len = last_index - start_index + 1; + user.upages_len = (last_index - start_index + 1) * sizeof(*out_pages); interval_tree_for_each_double_span(&span, &pages->access_itree, It would certainly hit gvt - but you should get WARN_ON's not hangs There is something wrong with the test suite that it isn't covering the above, I'm going to look into that today. Jason
