lkml.org 
[lkml]   [2018]   [Mar]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.15 078/122] virtio-net: disable NAPI only when enabled during XDP set
Date
4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jason Wang <jasowang@redhat.com>


[ 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 <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/virtio_net.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2040,8 +2040,9 @@ static int virtnet_xdp_set(struct net_de
}

/* 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);
@@ -2060,7 +2061,8 @@ static int virtnet_xdp_set(struct net_de
}
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;

\
 
 \ /
  Last update: 2018-03-07 21:20    [W:0.264 / U:1.984 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site