linux-kernel - Re: [PATCH 3/6] x86-mce: Clear CMCI enable on all claimed CMCI banks before reboot.

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Message-ID: <CA+8MBbJL6F3pvjX3a0eCNbutuKNudbLeMTbTdz+ZXZ2OOhX-KA@mail.gmail.com>
Date:	Thu, 10 Jul 2014 09:33:30 -0700
From:	Tony Luck <tony.luck@...il.com>
To:	Borislav Petkov <bp@...en8.de>
Cc:	Havard Skinnemoen <hskinnemoen@...gle.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Ewout van Bekkum <ewout@...gle.com>
Subject: Re: [PATCH 3/6] x86-mce: Clear CMCI enable on all claimed CMCI banks
 before reboot.

On Thu, Jul 10, 2014 at 9:24 AM, Borislav Petkov <bp@...en8.de> wrote:
> I'm saying that because I'm assuming BIOS will clear those MSRs upon
> warm reset. If it doesn't, then we have a bigger problem.

We  don't have to trust BIOS to do that. SDM section 15.3.2.5
"IA32_MCi_CTL2 MSRs" says:

After processor reset, IA32_MCi_CTL2 MSRs are zero’ed.

-Tony
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