From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH qemu-kvm] Add raw(af_packet) network backend to qemu Date: Thu, 28 Jan 2010 08:13:53 -0600 Message-ID: <4B619BA1.9010404@codemonkey.ws> References: <4B5F54E8.3080507@codemonkey.ws> <20100127180338.GB13730@redhat.com> <4B6099E0.40101@codemonkey.ws> <201001280912.04809.arnd@arndb.de> <20100128135644.GE3776@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Arnd Bergmann , Sridhar Samudrala , avi@redhat.com, markmc@redhat.com, ogerlitz@voltaire.com, kvm@vger.kernel.org, qemu-devel@vger.kernel.org To: "Michael S. Tsirkin" Return-path: Received: from mail-iw0-f172.google.com ([209.85.223.172]:50245 "EHLO mail-iw0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752182Ab0A1ON6 (ORCPT ); Thu, 28 Jan 2010 09:13:58 -0500 In-Reply-To: <20100128135644.GE3776@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 01/28/2010 07:56 AM, Michael S. Tsirkin wrote: >> Now, the most important use case I see for the raw socket interface >> in qemu is to get vhost-net and the qemu user implementation to >> support the same feature set. If you ask for a network setup involving >> a raw socket and vhost-net and the kernel can support raw sockets >> but for some reason fails to set up vhost-net, you should have a >> fallback that has the exact same semantics at a possibly significant >> performance loss. >> >> Arnd >> > Makes sense. A simple reason you can't do vhost-net would be > that you are using tcg. > Some good arguments have been raised in this thread. I really don't like making our security depend on something external to qemu that is not widely used or understood. That said, I'm not seeing a lot of great alternatives. I definitely like -net socket better than -net raw. In the absence of an extraordinarily clever solution, I think we may be stuck with doing this. Regards, Anthony Liguori