linux-kernel - Re: [PATCH v2] arch/x86: Fix boot_cpu

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Message-ID: <8DCDB4EE-A8DC-4368-88C6-D70F8F98170E@amazon.de>
Date:   Tue, 31 Jul 2018 15:31:07 +0000
From:   "Sironi, Filippo" <sironi@...zon.de>
To:     Borislav Petkov <bp@...en8.de>
CC:     Prarit Bhargava <prarit@...hat.com>,
        "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "tony.luck@...el.com" <tony.luck@...el.com>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>
Subject: Re: [PATCH v2] arch/x86: Fix boot_cpu_data.microcode version output


> On 31. Jul 2018, at 15:00, Borislav Petkov <bp@...en8.de> wrote:
> 
> On Tue, Jul 31, 2018 at 11:46:09AM +0000, Sironi, Filippo wrote:
>> There may be a chance of skipping this code, I think.
>> 
>> If the microcode is loaded on the hyperthread sibling of the boot cpu
>> before being loaded on the boot cpu, the boot cpu will exit earlier
>> from apply_microcode_intel() - in if (rev >= mc->hdr.rev) { ... }.
>> 
>> (This seems to be possible in apply_microcode_amd() as well.)
>> 
>> In my tree with the aforementioned change - Intel only - I also had
>> the following patch:
> 
> Yap, good catch.
> 
> -- 
> Regards/Gruss,
>    Boris.
> 
> ECO tip #101: Trim your mails when you reply.
> --
> 

Boris, Prarit,

I've sent the patch the I had in my tree and extended it to cover
apply_microcode_amd(). I don't have an AMD host available for testing,
can one of you give that a spin?

Thanks,
Filippo


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