From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Network throughput limits for local VM <-> VM communication Date: Thu, 11 Jun 2009 11:50:46 +0300 Message-ID: <4A30C566.7040109@redhat.com> References: <0199E0D51A61344794750DC57738F58E67D2398F9E@GVW1118EXC.americas.hpqcorp.net> <200906101529.47103.arnd@arndb.de> <0199E0D51A61344794750DC57738F58E67D2399710@GVW1118EXC.americas.hpqcorp.net> <200906110949.16197.arnd@arndb.de> <0199E0D51A61344794750DC57738F58E67D23998F5@GVW1118EXC.americas.hpqcorp.net> <4A30BD98.6040302@redhat.com> <0199E0D51A61344794750DC57738F58E67D2399972@GVW1118EXC.americas.hpqcorp.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Arnd Bergmann , Mark McLoughlin , "kvm@vger.kernel.org" To: "Fischer, Anna" Return-path: Received: from mx2.redhat.com ([66.187.237.31]:56476 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756693AbZFKIut (ORCPT ); Thu, 11 Jun 2009 04:50:49 -0400 In-Reply-To: <0199E0D51A61344794750DC57738F58E67D2399972@GVW1118EXC.americas.hpqcorp.net> Sender: kvm-owner@vger.kernel.org List-ID: Fischer, Anna wrote: > Not sure I understand. As far as I can see the packets are replicated on the tun/tap interface before they actually enter the bridge. So this is not about the bridge learning MAC addresses and flooding frames to unknown destinations. So I think this is different. > Okay. You said: > However, without VLANs, the tun > interface will pass packets to all tap interfaces. It has to, as it > doesn't know to which one the packet has to go to. Well, it shouldn't. The tun interface should pass the packets to just one tap interface. Can you post the qemu command line you're using? There's a gotcha there that can result in what you're seeing. -- error compiling committee.c: too many arguments to function