linux-kernel - Re: [Patch v3 Part2 3/9] x86/microcode/intel: Fix collect_cpu

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Date:   Tue, 31 Jan 2023 17:48:54 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Ashok Raj <ashok.raj@...el.com>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        LKML <linux-kernel@...r.kernel.org>, x86 <x86@...nel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Tony Luck <tony.luck@...el.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Alison Schofield <alison.schofield@...el.com>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Stefan Talpalaru <stefantalpalaru@...oo.com>,
        David Woodhouse <dwmw2@...radead.org>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Jonathan Corbet <corbet@....net>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Peter Zilstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Andrew Cooper <Andrew.Cooper3@...rix.com>,
        Boris Ostrovsky <boris.ostrovsky@...cle.com>,
        Martin Pohlack <mpohlack@...zon.de>
Subject: Re: [Patch v3 Part2 3/9] x86/microcode/intel: Fix collect_cpu_info()
 to reflect current microcode

On Mon, Jan 30, 2023 at 01:39:49PM -0800, Ashok Raj wrote:
> Currently collect_cpu_info() is only returning what was cached earlier
> instead of reading the current revision from the proper MSR.

Because this is how this is supposed to work: you collect what's
currently applied - which should be exactly the same as what's in the
MSR - and then see if there's a new patch in the cache and if so, update
it.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette