[PATCH AUTOSEL 6.4 05/17] vdpa/mlx5: Correct default number of queues when MQ is on

Sasha Levin
2023-08-29T13:33:43Z

From: Dragos Tatulea <dtatulea@nvidia.com>

[ Upstream commit 3fe024193340b225d1fd410d78c495434a9d68e0 ]

The standard specifies that the initial number of queues is the
default, which is 1 (1 tx, 1 rx).

Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
Message-Id: <20230727172354.68243-2-dtatulea@nvidia.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Tested-by: Lei Yang <leiyang@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/vdpa/mlx5/net/mlx5_vnet.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 279ac6a558d29..93a2520223b66 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -2447,7 +2447,15 @@ static int mlx5_vdpa_set_driver_features(struct vdpa_device *vdev, u64 features)
else
ndev->rqt_size = 1;

- ndev->cur_num_vqs = 2 * ndev->rqt_size;
+ /* Device must start with 1 queue pair, as per VIRTIO v1.2 spec, section
+ * 5.1.6.5.5 "Device operation in multiqueue mode":
+ *
+ * Multiqueue is disabled by default.
+ * The driver enables multiqueue by sending a command using class
+ * VIRTIO_NET_CTRL_MQ. The command selects the mode of multiqueue
+ * operation, as follows: ...
+ */
+ ndev->cur_num_vqs = 2;

update_cvq_info(mvdev);
return err;
--
2.40.1