From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH qemu-kvm] Add raw(af_packet) network backend to qemu Date: Wed, 27 Jan 2010 18:59:09 +0200 Message-ID: <20100127165909.GA13260@redhat.com> References: <1264538423.24933.144.camel@w-sridhar.beaverton.ibm.com> <4B5F54E8.3080507@codemonkey.ws> <4B5F5594.6080006@codemonkey.ws> <20100127092451.GC3476@redhat.com> <4B60488F.5020506@codemonkey.ws> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Sridhar Samudrala , avi@redhat.com, markmc@redhat.com, ogerlitz@voltaire.com, kvm@vger.kernel.org, qemu-devel@vger.kernel.org To: Anthony Liguori Return-path: Received: from mx1.redhat.com ([209.132.183.28]:25463 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755620Ab0A0RCY (ORCPT ); Wed, 27 Jan 2010 12:02:24 -0500 Content-Disposition: inline In-Reply-To: <4B60488F.5020506@codemonkey.ws> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Jan 27, 2010 at 08:07:11AM -0600, Anthony Liguori wrote: > On 01/27/2010 03:24 AM, Michael S. Tsirkin wrote: >> I am not sure I agree with this sentiment. The main issue being that >> macvtap doesn't exist on all kernels :). > > Neither does vhost ;-) If it were just that as the difference, I'd be > inclined to agree, but macvtap is much better from a security PoV. > >>> Not to mention that from a user perspective, raw makes almost no sense >>> as it's an obscure socket protocol family. >>> >>> A user wants to do useful things like bridged networking or direct VF >>> assignment. We should have -net backends that reflect things that make >>> sense to a user. >>> >>> Regards, >>> >>> Anthony Liguori >>> >> >> I agree to that. People don't even seem to agree whether it's a raw >> socket or a packet socket :) We need a better name for this option: what >> it really does is rely on an external device to loopback a packet to us, >> so how about -net loopback or -net extbridge? >> > > Specifically for VEPA, something like: > > -net extbridge,if=eth0 > > or even > > -net vepa,if=eth0 > > Would be fantastic. extbridge is IMO better. > I think the best way to achieve this is to > introduce a small helper that gets called and can create a macvtap > device and hand the file descriptor back to qemu :-) A builtin backend > would also be fine since we don't have the helper infrastructure. Excellent. Sridhar, this is actually not a lot of work on top of what you already posted. > Regards, > > Anthony Liguori