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Code Issues Releases Wiki Activity

virtio_net: fix xdp_rxq_info bug after suspend/resume

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The following sequence currently causes a driver bug warning
when using virtio_net:

  # ip link set eth0 up
  # echo mem > /sys/power/state (or e.g. # rtcwake -s 10 -m mem)
  <resume>
  # ip link set eth0 down

  Missing register, driver bug
  WARNING: CPU: 0 PID: 375 at net/core/xdp.c:138 xdp_rxq_info_unreg+0x58/0x60
  Call trace:
   xdp_rxq_info_unreg+0x58/0x60
   virtnet_close+0x58/0xac
   __dev_close_many+0xac/0x140
   __dev_change_flags+0xd8/0x210
   dev_change_flags+0x24/0x64
   do_setlink+0x230/0xdd0
   ...

This happens because virtnet_freeze() frees the receive_queue
completely (including struct xdp_rxq_info) but does not call
xdp_rxq_info_unreg(). Similarly, virtnet_restore() sets up the
receive_queue again but does not call xdp_rxq_info_reg().

Actually, parts of virtnet_freeze_down() and virtnet_restore_up()
are almost identical to virtnet_close() and virtnet_open(): only
the calls to xdp_rxq_info_(un)reg() are missing. This means that
we can fix this easily and avoid such problems in the future by
just calling virtnet_close()/open() from the freeze/restore handlers.

Aside from adding the missing xdp_rxq_info calls the only difference
is that the refill work is only cancelled if netif_running(). However,
this should not make any functional difference since the refill work
should only be active if the network interface is actually up.

Fixes: 754b8a21a9 ("virtio_net: setup xdp_rxq_info")
Signed-off-by: Stephan Gerhold <stephan.gerhold@kernkonzept.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20220621114845.3650258-1-stephan.gerhold@kernkonzept.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Stephan Gerhold 2022-06-21 13:48:44 +02:00 committed by Jakub Kicinski
parent 448ad88f80
commit 8af52fe9fd
1 changed files with 6 additions and 19 deletions
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25
drivers/net/virtio_net.c
View file

@ -2768,7 +2768,6 @@ static const struct ethtool_ops virtnet_ethtool_ops = {
static void virtnet_freeze_down(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int i;
/* Make sure no work handler is accessing the device */
flush_work(&vi->config_work);
@ -2776,14 +2775,8 @@ static void virtnet_freeze_down(struct virtio_device *vdev)
netif_tx_lock_bh(vi->dev);
netif_device_detach(vi->dev);
netif_tx_unlock_bh(vi->dev);
cancel_delayed_work_sync(&vi->refill);
if (netif_running(vi->dev)) {
for (i = 0; i < vi->max_queue_pairs; i++) {
napi_disable(&vi->rq[i].napi);
virtnet_napi_tx_disable(&vi->sq[i].napi);
}
}
if (netif_running(vi->dev))
virtnet_close(vi->dev);
}
static int init_vqs(struct virtnet_info *vi);
@ -2791,7 +2784,7 @@ static int init_vqs(struct virtnet_info *vi);
static int virtnet_restore_up(struct virtio_device *vdev)
{
struct virtnet_info *vi = vdev->priv;
int err, i;
int err;
err = init_vqs(vi);
if (err)
@ -2800,15 +2793,9 @@ static int virtnet_restore_up(struct virtio_device *vdev)
virtio_device_ready(vdev);
if (netif_running(vi->dev)) {
for (i = 0; i < vi->curr_queue_pairs; i++)
if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL))
schedule_delayed_work(&vi->refill, 0);
for (i = 0; i < vi->max_queue_pairs; i++) {
virtnet_napi_enable(vi->rq[i].vq, &vi->rq[i].napi);
virtnet_napi_tx_enable(vi, vi->sq[i].vq,
&vi->sq[i].napi);
}
err = virtnet_open(vi->dev);
if (err)
return err;
}
netif_tx_lock_bh(vi->dev);