vdpa/mlx5: roll back MR update after VQ setup failure

mlx5_vdpa_change_map() must install the new MR before rebuilding or
resuming virtqueues, because both paths read the MR keys from
mvdev->mres.mr[].

If rebuilding the virtqueue resources fails, the new MR must not remain
installed after its reference is released. Keep an extra reference to
the old MR before replacing it. On setup failure, restore the old MR;
the saved reference then becomes the map reference, while replacing the
new MR drops its map reference.

Make mlx5_vdpa_change_map() consume new_mr on all error paths so that
set_map_data() does not release an MR already released during rollback.

v2:
- Keep the new MR installed while virtqueues are rebuilt.
- Restore the old MR only after setup_vq_resources() fails.

Signed-off-by: Weimin Xiong <xiongwm2026@163.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Message-ID: <20260716054353.155805-1-xiongwm2026@163.com>

0 files changed, 0 insertions, 0 deletions