On Mon, Dec 07, 2020 at 10:51:44AM +0800, Jason Wang wrote:
>
> On 2020/12/6 下午6:57, Eli Cohen wrote:
> > Make sure to put write memory barrier after updating CQ consumer index
> > so the hardware knows that there are available CQE slots in the queue.
> >
> > Failure to do this can cause the update of the RX doorbell record to get
> > updated before the CQ consumer index resulting in CQ overrun.
> >
> > Change-Id: Ib0ae4c118cce524c9f492b32569179f3c1f04cc1
Michael, I left this gerrit ID by mistake. Can you remove it before
merging?
> > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5
> > devices")
> > Signed-off-by: Eli Cohen <e...@nvidia.com>
> > ---
> > drivers/vdpa/mlx5/net/mlx5_vnet.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > index 1f4089c6f9d7..295f46eea2a5 100644
> > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> > @@ -478,6 +478,11 @@ static int mlx5_vdpa_poll_one(struct mlx5_vdpa_cq *vcq)
> > static void mlx5_vdpa_handle_completions(struct mlx5_vdpa_virtqueue *mvq,
> > int num)
> > {
> > mlx5_cq_set_ci(&mvq->cq.mcq);
> > +
> > + /* make sure CQ cosumer update is visible to the hardware before
> > updating
> > + * RX doorbell record.
> > + */
> > + wmb();
> > rx_post(&mvq->vqqp, num);
> > if (mvq->event_cb.callback)
> > mvq->event_cb.callback(mvq->event_cb.private);
>
>
> Acked-by: Jason Wang <jasow...@redhat.com>
>
>
