Re: [PATCH] vdpa/mlx5: Correct default number of queues when MQ is on

[Lei Yang]

QE performed sanity testing on this patch using a real nic's
vhost_vdpa device with multi queues, everything works fine.

Tested-by: Lei Yang <leiyang@xxxxxxxxxx>




On Fri, Jul 28, 2023 at 9:42 AM Jason Wang <jasowang@xxxxxxxxxx> wrote:
>
> On Fri, Jul 28, 2023 at 1:25 AM Dragos Tatulea <dtatulea@xxxxxxxxxx> wrote:
> >
> > 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@xxxxxxxxxx>
> > Reviewed-by: Eugenio Pérez <eperezma@xxxxxxxxxx>
>
> Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
>
> Thanks
>
> > ---
> >  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 9138ef2fb2c8..6b6eb69a8a90 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -2517,7 +2517,15 @@ 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;
> > --
> > 2.41.0
> >
>