From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 77C3E2D8364 for ; Wed, 25 Mar 2026 16:42:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774456952; cv=none; b=QHKOW4JYXlbqD7J2JmRR7Y4++qO27ZhLl2obDgTLd7TfyaxElIGEsTVK5QQEIyQriPPca31p3gLcFY0ek2pCfuYZiHQtllZ0ytC9yTynss/abzHya6rIs3tahJF/gYgm2NgCyAC/xUtJ8b+NKRDVDu7ISKI5l166ZpsgnR2JYzI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774456952; c=relaxed/simple; bh=1oBjREXfJL33EEk0d/BwA0uQFnYNxbu3gTg9q5bQFpo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ecvbh3whtaF6T5h56Z7Pgr/STji5Rb1DdjhL+CAKYJJ3WvNQsQ6mCopbemqp1hGTd8GxtPUrvFpLTv35D4PkINnHwvOJ5uUj/W4DneTert/CuaIxS5G+NnORn19p7dvbi5Xet+Fx3H9VuYij+L5rBYIu7CVo8L8YcJO7kcVCTp0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=YDHTwXwe; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="YDHTwXwe" Received: from [IPV6:2601:646:8081:9481:619:3ffd:957c:6748] ([IPv6:2601:646:8081:9481:619:3ffd:957c:6748]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 62PGg2tP3200613 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Wed, 25 Mar 2026 09:42:03 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 62PGg2tP3200613 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026022301; t=1774456923; bh=MW/SMIpz36ot7zwGeskcIeImxtnf/KT8KrvAOPGKCZo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=YDHTwXweeYFnR0sjFC9HPshHX/zPZADWe6SBn4xS6dewengEg5Z+ib92VW6LFEvD1 MpsMeBQz9zzpg1KZvI+MPDT9T/A5+M7TP9P1OE39Pvuzc7kGjdhcleuEbZlKyI/L6W SCgUPL+D13Nw3GZHR6bWpjCXNoiR3LwQirWzZAI/IItFuwJqidtN5wfqYXPFIYMbk+ 8VCrvF8KmgNnjhg9cJ4zXZLY/miRHkWCYur+kSbIouvE0LNNEUoghIvGP6KoTZZklZ 4Y07GVM3Qs0BXBTBQnD62Y9Gmr3yUkdm6GxAndQyrQkAtPotfLu+8FH+Qv7VoSmYuX OT5bYpCa86gAA== Message-ID: <9bdc6bb7-0b74-4156-87dc-d2441f2a38ac@zytor.com> Date: Wed, 25 Mar 2026 09:41:57 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] x86/fred: enable FRED by default To: Borislav Petkov Cc: Sohil Mehta , Xin Li , Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "Peter Zijlstra (Intel)" , Kees Cook , "Ahmed S. Darwish" , linux-kernel@vger.kernel.org References: <20260323201510.1537333-1-hpa@zytor.com> <84489fd4-aa23-4ba1-b5a1-c1baafb6718d@intel.com> <927AE575-3C10-427E-9C4B-0238CBF8301E@zytor.com> <763cbc92-fda0-454e-a2dd-919671db15c3@zytor.com> <1fb5ae44-d443-414f-9d63-3efce4b73bc9@intel.com> <8cba266d-4d3d-4058-a4b4-b937395e50e3@intel.com> <20260324195351.GOacLrz90cagXTepUx@fat_crate.local> <8bb320bb-62e0-4252-8ef9-9b6aa04b02ba@zytor.com> <20260325163028.GAacQNpB7DlkyS4MJ4@fat_crate.local> Content-Language: en-US, sv-SE From: "H. Peter Anvin" In-Reply-To: <20260325163028.GAacQNpB7DlkyS4MJ4@fat_crate.local> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026-03-25 09:30, Borislav Petkov wrote: >> >> Well, it is useful for testing code paths for legacy hardware. > > ... which would presume you know what you're doing. > > clearcpuid= is not something you or I or anyone else wants to debug when > people start clearing random CPUID bits without knowing any better. > > Thus the tainting. > Exactly. -hpa