[PATCH vhost v2 20/24] vdpa/mlx5: Use suspend/resume during VQP change
From: Dragos Tatulea <dtatulea@nvidia.com>
Date: 2024-06-26 10:28:24
Also in:
linux-rdma, lkml, virtualization
Subsystem:
mellanox mlx5 vdpa driver, the rest, virtio core · Maintainers:
Dragos Tatulea, Linus Torvalds, "Michael S. Tsirkin", Jason Wang
Resume a VQ if it is already created when the number of VQ pairs increases. This is done in preparation for VQ pre-creation which is coming in a later patch. It is necessary because calling setup_vq() on an already created VQ will return early and will not enable the queue. For symmetry, suspend a VQ instead of tearing it down when the number of VQ pairs decreases. But only if the resume operation is supported. Reviewed-by: Cosmin Ratiu <redacted> Acked-by: Eugenio Pérez <eperezma@redhat.com> Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com> --- drivers/vdpa/mlx5/net/mlx5_vnet.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index ce1f6a1f36cd..324604b16b91 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c@@ -2130,14 +2130,22 @@ static int change_num_qps(struct mlx5_vdpa_dev *mvdev, int newqps) if (err) return err; - for (i = ndev->cur_num_vqs - 1; i >= 2 * newqps; i--) - teardown_vq(ndev, &ndev->vqs[i]); + for (i = ndev->cur_num_vqs - 1; i >= 2 * newqps; i--) { + struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i]; + + if (is_resumable(ndev)) + suspend_vq(ndev, mvq); + else + teardown_vq(ndev, mvq); + } ndev->cur_num_vqs = 2 * newqps; } else { ndev->cur_num_vqs = 2 * newqps; for (i = cur_qps * 2; i < 2 * newqps; i++) { - err = setup_vq(ndev, &ndev->vqs[i], true); + struct mlx5_vdpa_virtqueue *mvq = &ndev->vqs[i]; + + err = mvq->initialized ? resume_vq(ndev, mvq) : setup_vq(ndev, mvq, true); if (err) goto clean_added; }
--
2.45.1