From: Jason Wang <jasowang@redhat.com> To: Eli Cohen <elic@nvidia.com>, mst@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: lulu@redhat.com, maxime.coquelin@redhat.com Subject: Re: [PATCH v1] vdpa/mlx5: Use write memory barrier after updating CQ index Date: Thu, 10 Dec 2020 17:11:02 +0800 [thread overview] Message-ID: <26dd1676-ff63-4940-9b0d-d7097950c1e5@redhat.com> (raw) In-Reply-To: <20201209140004.15892-1-elic@nvidia.com> On 2020/12/9 下午10:00, Eli Cohen wrote: > Make sure to put dma 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. > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices") > Signed-off-by: Eli Cohen <elic@nvidia.com> > --- > V0 -> V1 > Use dma_wmb() instead of wmb() Acked-by: Jason Wang <jasowang@redhat.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 db87abc3cb60..43b0069ff8b1 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > @@ -479,6 +479,11 @@ 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. > + */ > + dma_wmb(); > rx_post(&mvq->vqqp, num); > if (mvq->event_cb.callback) > mvq->event_cb.callback(mvq->event_cb.private);
WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com> To: Eli Cohen <elic@nvidia.com>, mst@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: maxime.coquelin@redhat.com, lulu@redhat.com Subject: Re: [PATCH v1] vdpa/mlx5: Use write memory barrier after updating CQ index Date: Thu, 10 Dec 2020 17:11:02 +0800 [thread overview] Message-ID: <26dd1676-ff63-4940-9b0d-d7097950c1e5@redhat.com> (raw) In-Reply-To: <20201209140004.15892-1-elic@nvidia.com> On 2020/12/9 下午10:00, Eli Cohen wrote: > Make sure to put dma 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. > > Fixes: 1a86b377aa21 ("vdpa/mlx5: Add VDPA driver for supported mlx5 devices") > Signed-off-by: Eli Cohen <elic@nvidia.com> > --- > V0 -> V1 > Use dma_wmb() instead of wmb() Acked-by: Jason Wang <jasowang@redhat.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 db87abc3cb60..43b0069ff8b1 100644 > --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c > +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c > @@ -479,6 +479,11 @@ 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. > + */ > + dma_wmb(); > rx_post(&mvq->vqqp, num); > if (mvq->event_cb.callback) > mvq->event_cb.callback(mvq->event_cb.private); _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2020-12-10 9:12 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-12-09 14:00 [PATCH v1] vdpa/mlx5: Use write memory barrier after updating CQ index Eli Cohen 2020-12-10 9:11 ` Jason Wang [this message] 2020-12-10 9:11 ` Jason Wang
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