From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH][RFC] vmchannel a data channel between host and guest. Date: Tue, 14 Oct 2008 08:50:48 -0500 Message-ID: <48F4A3B8.8050603@us.ibm.com> References: <20081012124534.GK11435@redhat.com> <48F39443.4070203@codemonkey.ws> <20081014090540.GB13153@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Anthony Liguori , kvm@vger.kernel.org, Rusty Russell To: Gleb Natapov Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.141]:34836 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750976AbYJNNu4 (ORCPT ); Tue, 14 Oct 2008 09:50:56 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e1.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id m9EDoqnO014682 for ; Tue, 14 Oct 2008 09:50:52 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id m9EDoqf5241196 for ; Tue, 14 Oct 2008 09:50:52 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id m9EDoof0008977 for ; Tue, 14 Oct 2008 09:50:52 -0400 In-Reply-To: <20081014090540.GB13153@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Gleb Natapov wrote: > On Mon, Oct 13, 2008 at 01:32:35PM -0500, Anthony Liguori wrote: > >> > netlink was designed to be interface to userspace and is used like this > by different subsystems (not just network). What full blown socket (and > by that I presume you mean new address family) will give you over netlink? > File system? We need a simple stream semantics is this justify another > virtual file system? The choice was between char device and netlink. > Nelink was simpler and gives broadcast as a bonus. > The problem that you aren't solving, that IMHO is critical to solve, is the namespace issue. How do you determine who gets to use what channel in userspace and in the host? It's not a problem when you just have one tool, but if you expect people to start using this interface, arbitrating it quickly becomes a problem. sockets have a concept of addressing and a vfs has a natural namespace. That's what I was suggesting those interfaces. > >> Having a limit of only 4 links seems like a problem to me too. >> >> > This can be easily extended. > There shouldn't be an inherent limit in the userspace interface. Regards, Anthony Liguori