On 2022/10/31 20:18, Jason Gunthorpe wrote:
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..
yeah, this was grabbed before your posting. :-)
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.
sounds to be the cause. I didn't see any significant change in vfio_main.c
that may fail gvt. So should the iommufd changes. Then we will re-run the
test after your update.:-)
--
Regards,
Yi Liu
