Commit 4e09ff53 authored Feb 28, 2018 by Jason Wang Committed by David S. Miller Feb 28, 2018

virtio-net: disable NAPI only when enabled during XDP set



We try to disable NAPI to prevent a single XDP TX queue being used by
multiple cpus. But we don't check if device is up (NAPI is enabled),
this could result stall because of infinite wait in
napi_disable(). Fixing this by checking device state through
netif_running() before.

Fixes: 4941d472 ("virtio-net: do not reset during XDP set")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent ecc83275

drivers/net/virtio_net.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -2185,6 +2185,7 @@ static int virtnet_xdp_set(struct net_device dev, struct bpf_prog prog,
		}

		/* Make sure NAPI is not using any XDP TX queues for RX. */
		if (netif_running(dev))
		for (i = 0; i < vi->max_queue_pairs; i++)
		napi_disable(&vi->rq[i].napi);

		@@ -2205,6 +2206,7 @@ static int virtnet_xdp_set(struct net_device dev, struct bpf_prog prog,
		}
		if (old_prog)
		bpf_prog_put(old_prog);
		if (netif_running(dev))
		virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
		}