vdpa/mlx5: Clear vq ready indication upon device reset

[ Upstream commit e3aadf2 ]

After device reset, the virtqueues are not ready so clear the ready
field.

Failing to do so can result in virtio_vdpa failing to load if the device
was previously used by vhost_vdpa and the old values are ready.
virtio_vdpa expects to find VQs in "not ready" state.

Fixes: 1a86b37 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices")
Signed-off-by: Eli Cohen <elic@nvidia.com>
Link: https://lore.kernel.org/r/20210606053128.170399-1-elic@nvidia.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/vdpa/mlx5/net/mlx5_vnet.c

@@ -1752,6 +1752,14 @@ static void teardown_driver(struct mlx5_vdpa_net *ndev)
 	mutex_unlock(&ndev->reslock);
 }
 
+static void clear_vqs_ready(struct mlx5_vdpa_net *ndev)
+{
+	int i;
+
+	for (i = 0; i < ndev->mvdev.max_vqs; i++)
+		ndev->vqs[i].ready = false;
+}
+
 static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 {
 	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);
@@ -1762,6 +1770,7 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status)
 	if (!status) {
 		mlx5_vdpa_info(mvdev, "performing device reset\n");
 		teardown_driver(ndev);
+		clear_vqs_ready(ndev);
 		mlx5_vdpa_destroy_mr(&ndev->mvdev);
 		ndev->mvdev.status = 0;
 		ndev->mvdev.mlx_features = 0;