From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-244121.protonmail.ch (mail-244121.protonmail.ch [109.224.244.121]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 668E222A7E4 for ; Fri, 23 Jan 2026 09:26:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=109.224.244.121 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769160408; cv=none; b=Vnyi3aPeHWFq62k6pKSEk2RrZEY3aVOkkGy17NJFlTeLUbVlqGPfMYg+hSLF9YixkljVQHvvKcZD7xvNsTbMomq/s1z0wsBCEswrN5foxbTDhbi4ZWWqKLSpLHKJ3LP3RFW/gfjMWnI+04eLLtvq2xI4y/VjWNaUqEqqUt93MQc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769160408; c=relaxed/simple; bh=/83WhHABtJNx7oDm2c8v+E1owCW2/o+xOPNLXXwqUf8=; h=Date:To:From:Cc:Subject:Message-ID:MIME-Version:Content-Type; b=qOUgjJ0l/ONnySpbkBX7+IfMOVlUOfq8hDmhxQ0fKuZRWXMXKsJfjMwejAVB1HsKAHPL0SeV9NexCOHsDoGZCyDv6zfMlAlTF6bP14iZs/2/Q+i2++5Y003d9vJqI0ScQUCtC7LzpEnk5M4JOBt18XQSIlB3OCokMj/iqJW5BLs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pm.me; spf=pass smtp.mailfrom=pm.me; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b=Opin7Q8+; arc=none smtp.client-ip=109.224.244.121 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=pm.me Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pm.me Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b="Opin7Q8+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail3; t=1769160393; x=1769419593; bh=/83WhHABtJNx7oDm2c8v+E1owCW2/o+xOPNLXXwqUf8=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=Opin7Q8+H6xiz2qnv6vYjCBXlUAQmZAGqAO0+NcdQbwJQKesLCMxRM1wKeZ3Ie6Bc eQi7Q+YKDniw4IEeIxPoBMRRmZwllDadjDwvZhU5xM3yOp/mo/GQt+pQymNexmxkrU d4RXFW7VBOHoWaZGrFV3aWNDw04WXda45090CaR1IrDP/dSAiU91w0GGn0KoSToTfW HXVydmH65hk6pgv+HZ5Rj5TyJ/yknFL95oopaqqGB96/71Z1M/fa+TQVPNSoXKwX94 61dTy7+oLQ2iGJiNmj6ZfoGFsoGcfbhnu3nvOgUuCSoVcZcq/7cp2CPGs8IGPbBryb 8lms53ln9W9/Q== Date: Fri, 23 Jan 2026 09:26:28 +0000 To: Dave Hansen From: Maciej Wieczor-Retman Cc: linux-kernel@vger.kernel.org, sohil.mehta@intel.com, Borislav Petkov , "H. Peter Anvin" , Ingo Molnar , Jon Kohler , Pawan Gupta , "Peter Zijlstra (Intel)" , Thomas Gleixner , Tony Luck , x86@kernel.org Subject: Re: [PATCH 0/6] x86/cpu: Take Intel platform into account for old microcode checks Message-ID: Feedback-ID: 164464600:user:proton X-Pm-Message-ID: ccf4b1d3e075954a2b1d7e9dc9c81e9dd220cfab Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Tested the patchset by fabricating the scenario described below. No issues = were observed and the 'Running old microcode' warning has dissapeared after appl= ying the patches. Tested-by: Maciej Wieczor-Retman Kind regards Maciej Wiecz=C3=B3r-Retman (resending this email because I noticed the in-reply-to got lost for some reason) On 2026-01-19 at 11:50:47 -0800, Dave Hansen wrote: >There was a report[1] that CPUs running updated microcode were being >reported as running old microcode. The reason is that the old >microcode list neglects to take the platform ID into account. > >The platform ID is an Intel-only construct that allows CPUs that >otherwise have the same model/family/stepping to take different >microcode revisions. The microcode loader itself already checks this. >Only the recent "old_microcode" checker failed here. > >Treat the platform ID as a peer of model/family/stepping. Store it >in 'struct cpuinfo_x86', enable matching on it with with 'struct >x86_cpu_id', and flesh out the 'old_microcode' list with it. > >This fixes the report of an inaccurate, false positive in the >'old_microcode' vulnerability file. > >1. https://lore.kernel.org/all/38660F8F-499E-48CD-B58B-4822228A5941@nutani= x.com/