linux-kernel - Re: [PATCH 1/2] x86/microcode/AMD: Load late on both threads too

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Message-ID: <20230607200339.GDZIDim1s0FYkoeNDK@fat_crate.local>
Date:   Wed, 7 Jun 2023 22:03:39 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Dave Hansen <dave.hansen@...el.com>
Cc:     X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
        stable@...nel.org
Subject: Re: [PATCH 1/2] x86/microcode/AMD: Load late on both threads too

On Wed, Jun 07, 2023 at 12:36:53PM -0700, Dave Hansen wrote:
> What's the benefit of doing the loading on both threads?  I would have
> naively thought it was just wasted work.

I have the perfect example for this, see:

e7ad18d1169c ("x86/microcode/AMD: Apply the patch early on every logical thread")

so it is for reasons like that.

> I think I even have a back-burnered Intel patch around somewhere that
> ensures that we *never* load on both threads.

Interesting - I guess there are considerable differences in microcode
architecture between the two. :-)

-- 
Regards/Gruss,
    Boris.

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