From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56722) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxFye-0003Hk-V2 for qemu-devel@nongnu.org; Tue, 26 May 2015 10:37:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YxFya-0006zV-Fn for qemu-devel@nongnu.org; Tue, 26 May 2015 10:37:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40745) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YxFya-0006z9-8V for qemu-devel@nongnu.org; Tue, 26 May 2015 10:37:04 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t4QEb2kq024093 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Tue, 26 May 2015 10:37:03 -0400 Date: Tue, 26 May 2015 15:36:58 +0100 From: "Daniel P. Berrange" Message-ID: <20150526143658.GE30049@redhat.com> References: <1432322539-23719-1-git-send-email-thuth@redhat.com> <20150526125235.GJ13262@stefanha-thinkpad.redhat.com> <87egm34dk0.fsf@blackfin.pond.sub.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <87egm34dk0.fsf@blackfin.pond.sub.org> Subject: Re: [Qemu-devel] [RFC PATCH] net: Enable vlans and dump for -netdev, too, Reply-To: "Daniel P. Berrange" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Markus Armbruster Cc: Jason Wang , Thomas Huth , qemu-devel@nongnu.org, Stefan Hajnoczi , "Michael S. Tsirkin" On Tue, May 26, 2015 at 04:29:51PM +0200, Markus Armbruster wrote: > Stefan Hajnoczi writes: > > > On Fri, May 22, 2015 at 09:22:19PM +0200, Thomas Huth wrote: > >> So far, it is not possible to use the network dump interface > >> with the "-netdev" option yet, it only works with the legacy > >> "-net" option. To be able to use it with "-netdev", too, this > >> patch now enables the "vlan" packet distribution for the > >> "-netdev" option, too, so that you can now dump network packets > >> like this: > >> > >> qemu... -device e1000,netdev=myhub -netdev hubport,hubid=1,id=myhub \ > >> -netdev user,id=n1,vlan=1,tftp=/tmp/tftp,bootfile=zImage \ > >> -netdev dump,id=n2,vlan=1,file=/tmp/dump.dat > >> > >> Signed-off-by: Thomas Huth > >> --- > >> net/net.c | 3 +++ > >> qapi-schema.json | 1 + > >> 2 files changed, 4 insertions(+) > >> > >> [Note: I'm quite new to this area of the code, please review carefully > >> whether this approach makes sense or whether it should be done differently] > > > > We thought the QEMU "vlan" concept would be dropped completely in the > > future, so it was never added to -netdev. No patches to do that have > > been posted over the years, so I think it was more of a conceptual goal > > than a concrete requirement. > > Well, patches to do that first need to replace the VLAN-only dump > feature. > > To fully deprecate -net, we also have to replace -net nic for > configuring onboard NICs. > > Prior discussion: > http://lists.nongnu.org/archive/html/qemu-devel/2013-02/msg03743.html > > We haven't really tried either. > > Thomas's patch declares defeat on VLANs: it ports them to -netdev, > perpetuating the concept. > > > I'm okay with merging this but will leave some time for discussion > > before merging the patch. > > > > "Speak now or forever hold your peace" > > Sure we're ready to give up without having tried? Seems to me that we'd be better off taking the -netdev arg and adding a new parameter 'dump=filename' that can be used with any netdev backend. eg with tap -netdev tap,id=foo,fd=3,dump=/somefile,dumplen=1024 The use of a dedicated 'dump' network backend always appear rather strange as a conceptual approach, and I don't think we should propagate its use into -netdev Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|