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authorEli Cohen <elic@nvidia.com>2020-12-09 16:00:04 +0200
committerMichael S. Tsirkin <mst@redhat.com>2020-12-18 16:14:30 -0500
commit83ef73b27eb2363f44faf9c3ee28a3fe752cfd15 (patch)
treea52bae53e2520b068721b2deb337c85198e98b87 /drivers/vdpa
parentdb1e8bb6c63a77b74b0c6b49662fc50d49d5f90b (diff)
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vdpa/mlx5: Use write memory barrier after updating CQ index
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> Link: https://lore.kernel.org/r/20201209140004.15892-1-elic@nvidia.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'drivers/vdpa')
-rw-r--r--drivers/vdpa/mlx5/net/mlx5_vnet.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
index 1fa6fcac8299..81b932f72e10 100644
--- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
+++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
@@ -464,6 +464,11 @@ 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);