From: Stephan Gerhold stephan.gerhold@kernkonzept.com
[ Upstream commit 8af52fe9fd3bf5e7478da99193c0632276e1dfce ]
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: 754b8a21a96d ("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@kernkonze... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/virtio_net.c | 25 ++++++------------------- 1 file changed, 6 insertions(+), 19 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1a8fe5bacb19..415b26c80fe7 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -2315,7 +2315,6 @@ 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); @@ -2323,14 +2322,8 @@ 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); @@ -2338,7 +2331,7 @@ 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) @@ -2347,15 +2340,9 @@ 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);