From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [Qemu-devel] net packet storms with multiple NICs Date: Tue, 10 Nov 2009 19:38:48 -0600 Message-ID: <4AFA15A8.4070402@codemonkey.ws> References: <4AE1D903.5030709@msgid.tls.msk.ru> <1256316218.31881.85.camel@blaa> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Michael Tokarev , "qemu-devel@nongnu.org" , KVM list To: Mark McLoughlin Return-path: Received: from mail-gx0-f226.google.com ([209.85.217.226]:47613 "EHLO mail-gx0-f226.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756254AbZKKBip (ORCPT ); Tue, 10 Nov 2009 20:38:45 -0500 Received: by gxk26 with SMTP id 26so623696gxk.1 for ; Tue, 10 Nov 2009 17:38:50 -0800 (PST) In-Reply-To: <1256316218.31881.85.camel@blaa> Sender: kvm-owner@vger.kernel.org List-ID: Mark McLoughlin wrote: > On Fri, 2009-10-23 at 20:25 +0400, Michael Tokarev wrote: > >> I've two questions: >> >> o what's the intended usage of all-vlan-equal case, when kvm (or qemu) >> reflects packets from one interface to another? It's what bridge >> in linux is for, I think. >> > > I don't think it's necessarily an intended use-case for the vlan feature > > >> o why different -net guest -net host pairs are not getting different >> vlan= indexes by default, to stop the above-mentioned packet >> storms right away? I think it's a wise default to assign different >> pairs to different vlans, by counting -net host and -net guest >> sequences. >> > > With 0.12, we're going to be de-emphasising the vlan feature and instead > have NICs directly connected to host backends. The vlan feature will be > just another host backend, but optional > > You'll start guests with e.g.: > > -netdev tap,id=tap.0 -device virtio-net-pci,netdev=tap.0 > Which is not necessarily more friendly to a user, but it lays the foundation to be able to do a config file which in turns could be easily generated from a nic GUI/command line tool. Regards, Anthony Liguori