linux-stable/drivers/vdpa/mlx5
Eli Cohen 08dbd56602 vdpa/mlx5: Avoid destroying MR on empty iotlb
The current code treats an empty iotlb provdied in set_map() as a
special case and destroy the memory region object. This must not be done
since the virtqueue objects reference this MR. Doing so will cause the
driver unload to emit errors and log timeouts caused by the firmware
complaining on busy resources.

This patch treats an empty iotlb as any other change of mapping. In this
case, mlx5_vdpa_create_mr() will fail and the entire set_map() call to
fail.

This issue has not been encountered before but was seen to occur in a
non-official version of qemu. Since qemu is a userspace program, the
driver must protect against such case.

Fixes: 94abbccdf2 ("vdpa/mlx5: Add shared memory registration code")
Signed-off-by: Eli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20210811053713.66658-1-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-08-11 06:44:41 -04:00
..
core vdpa/mlx5: Avoid destroying MR on empty iotlb 2021-08-11 06:44:41 -04:00
net vdpa: support packed virtqueue for set/get_vq_state() 2021-07-08 07:49:01 -04:00
Makefile vdpa/mlx5: Connect mlx5_vdpa to auxiliary bus 2020-12-06 07:32:05 +02:00