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Date:   Tue, 25 Apr 2023 21:39:12 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     Tony Battersby <tonyb@cybernetics.com>
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>,
        Mario Limonciello <mario.limonciello@amd.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] x86/cpu: fix intermittent lockup on poweroff
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References: <3817d810-e0f1-8ef8-0bbd-663b919ca49b@cybernetics.com>
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On Tue, Apr 25, 2023 at 03:26:53PM -0400, Tony Battersby wrote:
> In stop_this_cpu(), make sure the CPUID leaf exists before accessing the
> leaf.  This fixes a lockup on poweroff 50% of the time due to the wrong
> branch being taken randomly on some CPUs (seen on Supermicro X8DTH-6F
> with Intel Xeon X5650).

Please send the output of

cpuid -r

from that machine.

Thx.

-- 
Regards/Gruss,
    Boris.

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