From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: KVM usability
Date: Mon, 1 Mar 2010 14:41:06 -0300
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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>
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Cc: Ingo Molnar <mingo@elte.hu>, Avi Kivity <avi@redhat.com>,
	Anthony Liguori <anthony@codemonkey.ws>,
	"Zhang, Yanmin" <yanmin_zhang@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>, ming.m.lin@intel.com,
	sheng.yang@intel.com, Jes Sorensen <Jes.Sorensen@redhat.com>,
	KVM General <kvm@vger.kernel.org>,
	Gleb Natapov <gleb@redhat.com>,
	Fr??d??ric Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Arjan van de Ven <arjan@infradead.org>
To: Zachary Amsden <zamsden@redhat.com>
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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.

- Arnaldo