From: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH 0/3] x86/microcode: support for microcode update in Xen
 dom0
Date: Wed, 12 Oct 2011 13:22:41 -0700
Message-ID: <4E95F711.2090004@zytor.com>
References: <cover.1317060617.git.jeremy.fitzhardinge@citrix.com> <4E94E1E5.4070505@goop.org> <20111012101615.GA14966@aftab> <4E95D9E7.6090304@zytor.com> <4E95E7FE.6050302@goop.org>
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To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Borislav Petkov <bp@amd64.org>, the arch/x86 maintainers <x86@kernel.org>, Tigran Aivazian <tigran@aivazian.fsnet.co.uk>, Xen Devel <xen-devel@lists.xensource.com>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>, Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>
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On 10/12/2011 12:18 PM, Jeremy Fitzhardinge wrote:
> If there were a general shift to "this is how we're going to do
> microcode in the future", then Xen will happily go along for the ride.

It *is* how we want to do microcode in the future.  There is a prototype 
for the Intel hardware side here; we just haven't had time to finalize 
it partly because I got pulled onto the kernel.org situation.

> But for right now, this patch seems like the pragmatic solution.

No.

> I think the real question is where there's something objectionable about
> the patch itself?

"It does something that is slightly broken on real hardware and totally 
broken for a hypervisor and perpetuates it, while still needing enabling?"

	-hpa