From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] AF_VMCHANNEL address family for guest<->host communication. Date: Mon, 15 Dec 2008 14:29:18 -0800 (PST) Message-ID: <20081215.142918.190909950.davem@davemloft.net> References: <4946717F.2090809@codemonkey.ws> <20081215.114315.165733593.davem@davemloft.net> <4946C1AA.4080404@codemonkey.ws> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: gleb@redhat.com, netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org To: anthony@codemonkey.ws Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:33505 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751712AbYLOW3Q (ORCPT ); Mon, 15 Dec 2008 17:29:16 -0500 In-Reply-To: <4946C1AA.4080404@codemonkey.ws> Sender: netdev-owner@vger.kernel.org List-ID: From: Anthony Liguori Date: Mon, 15 Dec 2008 14:44:26 -0600 > We want this communication mechanism to be simple and reliable as we > want to implement the backends drivers in the host userspace with > minimum mess. One implication of your statement here is that TCP is unreliable. That's absolutely not true. > Within the guest, we need the interface to be always available and > we need an addressing scheme that is hypervisor specific. Yes, we > can build this all on top of TCP/IP. We could even build it on top > of a serial port. Both have their down-sides wrt reliability and > complexity. I don't know of any zero-copy through the hypervisor mechanisms for serial ports, but I know we do that with the various virtualization network devices. > Do you have another recommendation? I don't have to make alternative recommendations until you can show that what we have can't solve the problem acceptably, and TCP emphatically can.