On Tue, Apr 27, 2021 at 03:02:34PM +0100, Dr. David Alan Gilbert wrote:
> * Laurent Vivier (lviv...@redhat.com) wrote:
> > In the failover case configuration, virtio_net_device_realize() uses an
> > add_migration_state_change_notifier() to add a state notifier, but this
> > notifier is not removed by the unrealize function when the virtio-net
> > card is unplugged.
> >
> > If the card is unplugged and a migration is started, the notifier is
> > called and as it is not valid anymore QEMU crashes.
> >
> > This patch fixes the problem by adding the
> > remove_migration_state_change_notifier() in virtio_net_device_unrealize().
> >
> > The problem can be reproduced with:
> >
> > $ qemu-system-x86_64 -enable-kvm -m 1g -M q35 \
> > -device pcie-root-port,slot=4,id=root1 \
> > -device pcie-root-port,slot=5,id=root2 \
> > -device
> > virtio-net-pci,id=net1,mac=52:54:00:6f:55:cc,failover=on,bus=root1 \
> > -monitor stdio disk.qcow2
> > (qemu) device_del net1
> > (qemu) migrate "exec:gzip -c > STATEFILE.gz"
> >
> > Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
> > 0x0000000000000000 in ?? ()
> > (gdb) bt
> > #0 0x0000000000000000 in ()
> > #1 0x0000555555d726d7 in notifier_list_notify (...)
> > at .../util/notify.c:39
> > #2 0x0000555555842c1a in migrate_fd_connect (...)
> > at .../migration/migration.c:3975
> > #3 0x0000555555950f7d in migration_channel_connect (...)
> > error@entry=0x0) at .../migration/channel.c:107
> > #4 0x0000555555910922 in exec_start_outgoing_migration (...)
> > at .../migration/exec.c:42
> >
> > Reported-by: Igor Mammedov <imamm...@redhat.com>
> > Signed-off-by: Laurent Vivier <lviv...@redhat.com>
>
> Yep, I think that's OK.
>
>
> Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
net stuff so I expect Jason will merge this ...
> > ---
> > hw/net/virtio-net.c | 1 +
> > 1 file changed, 1 insertion(+)
> >
> > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> > index 66b9ff451185..914051feb75b 100644
> > --- a/hw/net/virtio-net.c
> > +++ b/hw/net/virtio-net.c
> > @@ -3373,6 +3373,7 @@ static void virtio_net_device_unrealize(DeviceState
> > *dev)
> >
> > if (n->failover) {
> > device_listener_unregister(&n->primary_listener);
> > + remove_migration_state_change_notifier(&n->migration_state);
> > }
> >
> > max_queues = n->multiqueue ? n->max_queues : 1;
> > --
> > 2.30.2
> >
> --
> Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
