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 38668174EC0 for ; Thu, 4 Jul 2024 07:59:37 +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=1720079980; cv=none; b=qXI2U90qlgylk+gleBXY3Lvpyyu8sMd1InsLc9Dl3APVaER88j7fVSQXzxGRgOUyS4hlQJhxckNTsL8/AgGMqOksg107Nm3V3sRvpxtZykcebrtaXU66oTu6TdjCeYzEKBBweRGQXORUtk2nFPxw2h0yCbn5S5hFH6+Qo/PEkoY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720079980; c=relaxed/simple; bh=uCHLNn9xW6DSGJxm2VvdezS3o/2wBq8N3JtHJLSItQ0=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=aRIOdJVakUtEffCC2GYxEb+FB/SgiSn2rRtdOBz9H4vV58toYnAiWagW0m1MRPnihwgmk+Rbtu7usgXtpo8OERb+iEHGTuZfUDQNrvIA4iIghTdajXkaMr804czMa0+odHDDiS9yPssLIAlbq9KAqoKx6cQHgDXrwVn7jxcWpps= 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=ZdFL+0i1; 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="ZdFL+0i1" Received: from [127.0.0.1] ([76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.17.2/8.17.1) with ESMTPSA id 4647wvQp1325117 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Thu, 4 Jul 2024 00:58:58 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 4647wvQp1325117 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024061501; t=1720079939; bh=TEQkEq5fwuA0kITHZp4giwTncsUgvpmrSlBYawflwQk=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=ZdFL+0i18i6PPQaxlfiU4r04LCx+59xPAg3LyoMUMaKq7NRDhHSr6GguEvbUEXO7i jhEnIUwxRobrrEJYv6+vAaFTicRCPGnLYW1WojtMKyJhnLG66C7j7IfZ6DPOx7GvDr oYe7dDxhOi3jeYoGRac3I5Gi9ZvWqh0md+CPRqtnjuQ+/nLMfPlhB9IrCbtI8IXNQ5 0t4yPtGrLWKKhD8SYkMgpf9DF10lc+YrfZaYUVo8FmCdlJRHTBmpuTYi9wtxNjAbTZ +CYIaM7lB8l8S2RAKcHDL1ir/nNpEiz/MZMbD9eqPo9MhkcP8tkWpTntg2p7XSuSG+ Osj4+UeVyZ8Qw== Date: Thu, 04 Jul 2024 00:58:55 -0700 From: "H. Peter Anvin" To: Xin Li , Andrew Cooper , Borislav Petkov , dave.hansen@intel.com CC: linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, x86@kernel.org, peterz@infradead.org, nik.borisov@suse.com, houwenlong.hwl@antgroup.com Subject: Re: [PATCH v1 2/4] x86/fred: Write to FRED MSRs with wrmsrns() User-Agent: K-9 Mail for Android In-Reply-To: References: <9063b0fe-e8f3-44ff-b323-b2b6c338690f@intel.com> <172002205406.3280081.14523962650685954182@Ubuntu-2204-jammy-amd64-base> <15f56e6a-6edd-43d0-8e83-bb6430096514@citrix.com> <56909a1e-b360-4090-945e-cf6ec623cccc@citrix.com> Message-ID: 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 On July 3, 2024 10:57:29 PM PDT, Xin Li wrote: >On 7/3/2024 9:18 AM, Andrew Cooper wrote: >> On 03/07/2024 5:06 pm, H=2E Peter Anvin wrote: >>> I believe tglx declared53 to use them unconditionally since FRED depe= nds on WRMSRNS (and the kernel enforces that=2E) >>=20 >> I know that Linux has chosen to have this as a software-enforced >> requirement=2E >>=20 >> The dependency does not exist architecturally, and just because it >> happens to be true on Intel processors doesn't mean it's true of other >> implementations=2E > >Won't it be way better if we could have all x86 vendors agree on it? > > It was tglx' explicit request to keep it simple unless someone objects=2E = All it would take is for someone to come up with a countercase=2E