linux-kernel - Re: new cmdline parameter disable_cpu

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Date:	Tue, 5 Jan 2016 00:16:33 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Piotr Dąbrowski <ultr@...r.pl>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: new cmdline parameter disable_cpu_features= (microcode update?)

On Mon, Jan 04, 2016 at 11:55:57PM +0100, Piotr Dąbrowski wrote:
> Is such thing even possible? And would it be a reasonable thing to do
> (maybe the rest of the microcode would break badly without the factory
> flags set)?

You cannot change the microcode patches - they're supplied by the CPU
vendors as is and are signed/encrypted.

In an ideal world, we should have BIOS disable options for all CPU
features which could turn out to be problematic so that the user remains
in control. Without the need to be applying microcode patches even.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
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