Comment # 12 on bug 919154 from Jan Beulich

(In reply to Neil F Brown from comment #10)
> > Booting to kernel 3.19, the guest is no longer accessible via network. 
> 
> seems to confirm that.  Has anything changed in the "Virtual ethernet
> driver" between 3.18 and 3.19??

Nothing at all (also not in the backend, for the avoidance of doubt). There was
a change (only indirectly related to 3.19) in how stats are being collected (or
more precisely the locking involved there), but an eventual problem introduced
there should manifest quite obviously in e.g. soft lockup messages. And that
change was also already carried through to our SLE12 kernel and hasn't caused
any known problems there so far.