Re: [PATCH] virtio-net: failover: add missing remove_migration_state_change_notifier()

[Jason Wang]

在 2021/5/5 下午3:46, Laurent Vivier 写道:
> On 29/04/2021 09:26, Jason Wang wrote:
> > 在 2021/4/28 下午6:14, Michael S. Tsirkin 写道:
> > > On Tue, Apr 27, 2021 at 03:02:34PM +0100, Dr. David Alan Gilbert wrote:
> > > > * Laurent Vivier (lvivier@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 <imammedo@redhat.com>
> > > > > Signed-off-by: Laurent Vivier <lvivier@redhat.com>
> > > > Yep, I think that's OK.
> > > >
> > > >
> > > > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > >
> > > net stuff so I expect Jason will merge this ...
> >
> > Ok, I've queued this.
> Thank you.
>
> Any idea when the PR will be sent?


I would be no later than the end of this week. I plan to merge RSS so I 
want to have some basic for that.

Thanks


> Thanks,
> Laurent