Subject: Re: [PATCH] tun: teach the tun/tap driver to support netpoll

From: Cong Wang <[email-masked]>
Date: Thu, 16 Jun 2011 09:44:39 +0800

于 2011年06月15日 23:25, Neil Horman 写道:
> Commit 8d8fc29d02a33e4bd5f4fa47823c1fd386346093 changed the behavior of slave
> devices in regards to netpoll.  Specifically it created a mutually exclusive
> relationship between being a slave and a netpoll-capable device.  This creates
> problems for KVM because guests relied on needing netconsole active on a slave
> device to a bridge.  Ideally libvirtd could just attach netconsole to the bridge
> device instead, but thats currently infeasible, because while the bridge device
> supports netpoll, it requires that all slave interface also support it, but the
> tun/tap driver currently does not.  The most direct solution is to teach tun/tap
> to support netpoll, which is implemented by the patch below.
>

Yeah, bridge checks if all the underlying devices support netpoll,
that is why Rik saw the failure.

> I've not tested this yet, but its pretty straightforward.
>
> Signed-off-by: Neil Horman<[email-masked]>
> Reported-by: Rik van Riel<[email-masked]>
> CC: Rik van Riel<[email-masked]>
> CC: Maxim Krasnyansky<[email-masked]>
> CC: Cong Wang<[email-masked]>
> CC: "David S. Miller"<[email-masked]>

Reviewed-by: WANG Cong <[email-masked]>

Thanks for fixing it!