linux-kernel - Re: [PATCH] x86: Add check for P5 to microcode_intel

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Message-ID: <20130419205515.GA3075@pd.tnic>
Date:	Fri, 19 Apr 2013 22:55:15 +0200
From:	Borislav Petkov <bp@...en8.de>
To:	Bryan O'Donoghue <bryan.odonoghue.lkml@...us-software.ie>
Cc:	hpa@...or.com, linux-kernel@...r.kernel.org, x86@...nel.org,
	fenghua.yu@...el.com
Subject: Re: [PATCH] x86: Add check for P5 to microcode_intel_early

On Fri, Apr 19, 2013 at 09:35:18PM +0100, Bryan O'Donoghue wrote:
> Just returning X86_VENDOR_UNKNOWN - won't fix the bug though - after
> all MSR_IA32_UCODE_REV is also x86_family() >= 6

What are you talking about?

If you return X86_VENDOR_UNKNOWN from x86_vendor(),
load_ucode_intel_bsp() and load_ucode_intel_ap() won't be called and no
non-existing MSRs will be accessed.

Just filter out P5 and earlier. The code already does that for CPUs
which don't have CPUID.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
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