From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965480AbWJ3JIj (ORCPT ); Mon, 30 Oct 2006 04:08:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965483AbWJ3JIj (ORCPT ); Mon, 30 Oct 2006 04:08:39 -0500 Received: from mis011-1.exch011.intermedia.net ([64.78.21.128]:11132 "EHLO mis011-1.exch011.intermedia.net") by vger.kernel.org with ESMTP id S965480AbWJ3JIh (ORCPT ); Mon, 30 Oct 2006 04:08:37 -0500 Message-ID: <4545C110.8080204@qumranet.com> Date: Mon, 30 Oct 2006 11:08:32 +0200 From: Avi Kivity User-Agent: Thunderbird 1.5.0.7 (X11/20061008) MIME-Version: 1.0 To: Arnd Bergmann CC: kvm-devel@lists.sourceforge.net, linux-kernel Subject: Re: [kvm-devel] [PATCH][RFC] KVM: prepare user interface for smp guests References: <4544AD24.4040801@qumranet.com> <200610300101.11245.arnd@arndb.de> In-Reply-To: <200610300101.11245.arnd@arndb.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 30 Oct 2006 09:08:36.0747 (UTC) FILETIME=[FB92BDB0:01C6FC02] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Arnd Bergmann wrote: > Separating the objects into different file descriptors sounds like a > good idea, but reusing an open dentry/inode with a new file and different > file operations is a rather unusual way to do it. Yes, it doesn't feel right. > Your concept of allocating > a new context on each open is already weird, but there have been other > examples of that before. > Actually that seemed to me quite natural. > I'd suggest going to a syscall-based model with your own file system right > away, even if you don't use the spufs approach but something in the middle: > > * You do a trivial nonmountable new file system with anonymous objects, > similar to eventpollfs, and hand out file descriptors to inodes in it, > for both the kvm and the vcpu objects. > * You replace the syscall you'd normally use to hand out a new kvm instance > with an ioctl on /dev/kvm, and don't allow any other operations on that > device. > > This would be a much more consistant object model, compared with other > generic kernel functionality that is not bound to an actual device. > You still have all the flexibility of a loadable module without core > kernel changes for the development phase, and can easily switch to real > syscalls when merging it into mainline. > I agree, that sounds like a good plan. I'll look into it. BTW, what does lsof show for spufs users? I thought lsof /dev/kvm would be a good way to look for virtual machines. -- error compiling committee.c: too many arguments to function