net/virtio: add barrier in interrupt enable

Typically, after enabling Rx interrupt, a check should be done
to make sure that there is no new incoming packets before going
to sleep. So a barrier is needed to make sure that any following
check won't happen before the interrupt is actually enabled.

Fixes: c056be239db5 ("net/virtio: add Rx interrupt enable/disable functions")
Cc: stable@dpdk.org
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
index 78ba7bd..ff16fb6 100644 (file)
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -850,10 +850,12 @@ virtio_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
 static int
 virtio_dev_rx_queue_intr_enable(struct rte_eth_dev *dev, uint16_t queue_id)
 {
+       struct virtio_hw *hw = dev->data->dev_private;
        struct virtnet_rx *rxvq = dev->data->rx_queues[queue_id];
        struct virtqueue *vq = rxvq->vq;
 
        virtqueue_enable_intr(vq);
+       virtio_mb(hw->weak_barriers);
        return 0;
 }