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>
8af52fe9fd