From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zachary Amsden Subject: Re: KVM usability Date: Mon, 01 Mar 2010 08:29:12 -1000 Message-ID: <4B8C0778.8050908@redhat.com> References: <20100226090147.GH15885@elte.hu> <4B879A2F.50203@redhat.com> <20100226103545.GA7463@elte.hu> <4B87A6BF.3090301@redhat.com> <20100226111734.GE7463@elte.hu> <4B8813F2.8090208@redhat.com> <20100227105643.GA17425@elte.hu> <4B893B2B.40301@redhat.com> <20100227172546.GA31472@elte.hu> <4B8BEFC7.2040000@redhat.com> <20100301174106.GB2362@ghostprotocols.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Ingo Molnar , Avi Kivity , Anthony Liguori , "Zhang, Yanmin" , Peter Zijlstra , ming.m.lin@intel.com, sheng.yang@intel.com, Jes Sorensen , KVM General , Gleb Natapov , Fr??d??ric Weisbecker , Thomas Gleixner , "H. Peter Anvin" , Peter Zijlstra , Arjan van de Ven To: Arnaldo Carvalho de Melo Return-path: Received: from mx1.redhat.com ([209.132.183.28]:48849 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751224Ab0CASaA (ORCPT ); Mon, 1 Mar 2010 13:30:00 -0500 In-Reply-To: <20100301174106.GB2362@ghostprotocols.net> Sender: kvm-owner@vger.kernel.org List-ID: On 03/01/2010 07:41 AM, Arnaldo Carvalho de Melo wrote: > Em Mon, Mar 01, 2010 at 06:48:07AM -1000, Zachary Amsden escreveu: > >> On 02/27/2010 07:25 AM, Ingo Molnar wrote: >> >>> I'm not talking about moving it into a kernel _module_ - albeit that >>> alone is a worthwile thing to do for any performance sensitive hw >>> component. >>> >>> I was talking about the option of a clean, stripped down Qemu base >>> hosted in the kernel proper, in linux/tools/kvm/ or so. If i were >>> running a virtualization effort it would be the first place i'd >>> consider to put my tooling into. >>> > >> So ripping out a clean part interface like PCI bus infrastructure and >> using it in the kernel, for example, does nothing except put that >> infrastructure in two different places, because everything the kernel >> does, userspace will have to do again anyway. So now you have twice as >> much code involving the same idea and you have to keep the pieces in >> sync and from trampling each other. >> >> The only parts that warrant such complexity and high risk for bugs are >> performance critical things like the PIT and APIC. >> > I guess there is some misunderstanding here, the tools/ directory that > lives in the kernel _sources_, has no kernel source, its all userspace > stuff. Yeah, no morning coffee :=) So instead we are advocating forking qemu into the kernel. That makes even less sense. It's not sustainable or eco-friendly to either community. Zach