From: Jason Wang Date: Wed, 28 Feb 2018 10:20:04 +0000 (+0800) Subject: virtio-net: disable NAPI only when enabled during XDP set X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=99a781947c2ab1e7b77bc88017fa58e78ff5c3ba;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git virtio-net: disable NAPI only when enabled during XDP set [ Upstream commit 4e09ff5362843dff3accfa84c805c7f3a99de9cd ] 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: 4941d472bf95b ("virtio-net: do not reset during XDP set") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 7927e28f5336..6a785595b9b8 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -1995,8 +1995,9 @@ 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. */ - for (i = 0; i < vi->max_queue_pairs; i++) - napi_disable(&vi->rq[i].napi); + if (netif_running(dev)) + for (i = 0; i < vi->max_queue_pairs; i++) + napi_disable(&vi->rq[i].napi); netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp); err = _virtnet_set_queues(vi, curr_qp + xdp_qp); @@ -2015,7 +2016,8 @@ static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, } if (old_prog) bpf_prog_put(old_prog); - virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); + if (netif_running(dev)) + virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi); } return 0;