After commit 8d8fc29d02a33e4bd5f4fa47823c1fd386346093
(netpoll: disable netpoll when enslave a device), it is
no longer possible to use netconsole together with bridged
KVM guests.
I can see why the change looked reasonable from a networking
point of view, but this has completely disabled netconsole
functionality for a common KVM use case.
After the change, netconsole refuses to bind to eth0.
Since the bridge interface does not support polling,
netconsole cannot use that, either.