Commit 0fe963d6 authored by Dragos Tatulea's avatar Dragos Tatulea Committed by Michael S. Tsirkin
Browse files

vdpa/mlx5: Re-create HW VQs under certain conditions 



There are a few conditions under which the hardware VQs need a full
teardown and setup:

- VQ size changed to something else than default value. Hardware VQ size
  modification is not supported.

- User turns off certain device features: mergeable buffers, checksum
  virtio 1.0 compliance. In these cases, the TIR and RQT need to be
  re-created.

Add a needs_teardown configuration variable and set it when detecting
the above scenarios. On next DRIVER_OK, the resources will be torn down
first.

Reviewed-by: default avatarCosmin Ratiu <cratiu@nvidia.com>
Acked-by: default avatarEugenio Pérez <eperezma@redhat.com>
Signed-off-by: default avatarDragos Tatulea <dtatulea@nvidia.com>
Message-Id: <20240626-stage-vdpa-vq-precreate-v2-22-560c491078df@nvidia.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent ffb1aae4

drivers/vdpa/mlx5/net/mlx5_vnet.c

+15 −0
Original line number Diff line number Diff line
@@ -2390,6 +2390,7 @@ static void mlx5_vdpa_set_vq_num(struct vdpa_device *vdev, u16 idx, u32 num) 
        }



	mvq = &ndev->vqs[idx];

	ndev->needs_teardown = num != mvq->num_ent;

	mvq->num_ent = num;

}
@@ -2800,6 +2801,7 @@ static int mlx5_vdpa_set_driver_features(struct vdpa_device *vdev, u64 features) 
	struct mlx5_vdpa_dev *mvdev = to_mvdev(vdev);

	struct mlx5_vdpa_net *ndev = to_mlx5_vdpa_ndev(mvdev);

	u64 old_features = mvdev->actual_features;

	u64 diff_features;

	int err;



	print_features(mvdev, features, true);
@@ -2822,6 +2824,14 @@ static int mlx5_vdpa_set_driver_features(struct vdpa_device *vdev, u64 features) 
		}

	}



	/* When below features diverge from initial device features, VQs need a full teardown. */

#define NEEDS_TEARDOWN_MASK (BIT_ULL(VIRTIO_NET_F_MRG_RXBUF) | \

			     BIT_ULL(VIRTIO_NET_F_CSUM) | \

			     BIT_ULL(VIRTIO_F_VERSION_1))



	diff_features = mvdev->mlx_features ^ mvdev->actual_features;

	ndev->needs_teardown = !!(diff_features & NEEDS_TEARDOWN_MASK);



	update_cvq_info(mvdev);

	return err;

}
@@ -3038,6 +3048,7 @@ static void teardown_vq_resources(struct mlx5_vdpa_net *ndev) 
	destroy_rqt(ndev);

	teardown_virtqueues(ndev);

	ndev->setup = false;

	ndev->needs_teardown = false;

}



static int setup_cvq_vring(struct mlx5_vdpa_dev *mvdev)
@@ -3078,6 +3089,10 @@ static void mlx5_vdpa_set_status(struct vdpa_device *vdev, u8 status) 
				goto err_setup;

			}

			register_link_notifier(ndev);



			if (ndev->needs_teardown)

				teardown_vq_resources(ndev);



			if (ndev->setup) {

				err = resume_vqs(ndev);

				if (err) {

drivers/vdpa/mlx5/net/mlx5_vnet.h

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ struct mlx5_vdpa_net { 
	struct dentry *rx_dent;

	struct dentry *rx_table_dent;

	bool setup;

	bool needs_teardown;

	u32 cur_num_vqs;

	u32 rqt_size;

	bool nb_registered;