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 11:44:27 +0200 Message-ID: <20100127094427.GE3476@redhat.com> References: <1264538423.24933.144.camel@w-sridhar.beaverton.ibm.com> <4B5F5594.6080006@codemonkey.ws> <20100127092451.GC3476@redhat.com> <201001271034.35904.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Anthony Liguori , Sridhar Samudrala , avi@redhat.com, markmc@redhat.com, ogerlitz@voltaire.com, kvm@vger.kernel.org, qemu-devel@vger.kernel.org To: Arnd Bergmann Return-path: Received: from mx1.redhat.com ([209.132.183.28]:62675 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752900Ab0A0Jrm (ORCPT ); Wed, 27 Jan 2010 04:47:42 -0500 Content-Disposition: inline In-Reply-To: <201001271034.35904.arnd@arndb.de> Sender: kvm-owner@vger.kernel.org List-ID: On Wed, Jan 27, 2010 at 10:34:35AM +0100, Arnd Bergmann wrote: > On Wednesday 27 January 2010, 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 :). macvlan also requires hardware > > support, packet socket can work with any network card in promisc mode. > > To be clear, macvlan does not require hardware support, it will happily > put cards into promiscous mode if they don't support multiple mac addresses. > > > 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? > > I think -net socket,fd should just be (trivially) extended to work with raw > sockets out of the box, with no support for opening it. Then you can have > libvirt or some wrapper open a raw socket and a private namespace and just pass it > down. That'd work. Anthony? > If you really want to let qemu open the socket itself, -net socket,raw=eth0 > is probably closer to what you want than a new -net xxx option. > > Arnd So again if implemented this probably should be -net socket,raw,loopback=eth0 or -net socket,raw,extbridge=eth0 or some such, just to make it abundantly clear that you must not bind it to a regular ethernet device. -- MST