From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark McLoughlin Subject: Re: [Qemu-devel] net packet storms with multiple NICs Date: Fri, 23 Oct 2009 17:43:38 +0100 Message-ID: <1256316218.31881.85.camel@blaa> References: <4AE1D903.5030709@msgid.tls.msk.ru> Reply-To: Mark McLoughlin Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "qemu-devel@nongnu.org" , KVM list To: Michael Tokarev Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26470 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752296AbZJWQpg (ORCPT ); Fri, 23 Oct 2009 12:45:36 -0400 In-Reply-To: <4AE1D903.5030709@msgid.tls.msk.ru> Sender: kvm-owner@vger.kernel.org List-ID: 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 Cheers, Mark.