From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH 2/2] vhost_net: a kernel-level virtio server Date: Wed, 12 Aug 2009 14:27:31 -0500 Message-ID: <4A8317A3.4030303@codemonkey.ws> References: <200908121903.22325.arnd@arndb.de> <20090812172141.GA29966@redhat.com> <200908121959.47222.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org, "Ira W. Snyder" , netdev@vger.kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org To: Arnd Bergmann Return-path: Received: from mail-qy0-f196.google.com ([209.85.221.196]:45062 "EHLO mail-qy0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752471AbZHLT1j (ORCPT ); Wed, 12 Aug 2009 15:27:39 -0400 In-Reply-To: <200908121959.47222.arnd@arndb.de> Sender: netdev-owner@vger.kernel.org List-ID: Arnd Bergmann wrote: >> As I pointed out earlier, most code in virtio net is asymmetrical: guest >> provides buffers, host consumes them. Possibly, one could use virtio >> rings in a symmetrical way, but support of existing guest virtio net >> means there's almost no shared code. >> > > The trick is to swap the virtqueues instead. virtio-net is actually > mostly symmetric in just the same way that the physical wires on a > twisted pair ethernet are symmetric (I like how that analogy fits). > It's already been done between two guests. See http://article.gmane.org/gmane.linux.kernel.virtualization/5423 Regards, Anthony Liguori