From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: QEMU PIC indirection patch for in-kernel APIC work Date: Thu, 05 Apr 2007 12:58:30 +0300 Message-ID: <4614C846.7070605@qumranet.com> References: <4613BC6B.1070708@codemonkey.ws> <4613BF07.50606@qumranet.com> <4613C993.9020405@codemonkey.ws> <4613CC01.1090500@qumranet.com> <4613CDB2.4000903@codemonkey.ws> <4613D001.3040606@qumranet.com> <20070404200112.GA6070@elte.hu> <4614098F.2030307@us.ibm.com> <20070404212103.GA19026@elte.hu> <1175728768.12230.593.camel@localhost.localdomain> <20070405093033.GC25448@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org, netdev To: Ingo Molnar Return-path: In-Reply-To: <20070405093033.GC25448-X9Un+BFzKDI@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: netdev.vger.kernel.org Ingo Molnar wrote: > so right now the only option for a clean codebase is the KVM in-kernel > code. I strongly disagree with this. Bad code in userspace is not an excuse for shoving stuff into the kernel, where maintaining it is much more expensive, and the cause of a mistake can be system crashes and data loss, affecting unrelated processes. If we move something into the kernel, we'd better have a really good reason for it. Qemu code _is_ crufty. We can do one of three things: 1. live with it 2. fork it and clean it up 3. clean it up incrementally and merge it upstream Currently we're doing (1). You're suggesting a variant of (2), fork plus move into the kernel. The right thing to do IMO is (3), but I don't see anybody volunteering. Qemu picked up additional committers recently and I believe they would be receptive to cleanups. [In the *pic/pit case, we have other reasons to push things into the kernel. But "this code is crap, let's rewrite it in the kernel" is not a justification I'll accept. I'd be much happier if we could quantify these other reasons.] -- error compiling committee.c: too many arguments to function ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV