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 542EF41C92 for ; Mon, 1 Jul 2024 08:02:32 +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=1719820955; cv=none; b=KLls0+dPuQ8MYqNX3Z361e+bFcrKK6S7L6ngnWDpFkQRCb1Arpwx6TgOmI1OkmFH+MxkjzQbtNuY3e2iUCD39ierIYhUZIDHohdM5O44soTulf+/AlyoX7zbfBhzQahpQ1CyZTdl8gJ6lUPaWKIg6f3i08jQbMNsatM+AfXsTvY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719820955; c=relaxed/simple; bh=PBSMLOm5Po8X5BwRqt/ewbQVdKOLBiM1iMUfzgSaeE8=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=qoIRJuMGkJO7z01rlMGtJdoCCPJ/JLbRxDInuLTpCsSR8yB5tn2i+nsT+qFdbDmQ3Pu7KWgCR+4RXKaq11j9UX85X+ECseZJbJrIzEf8dmzh5EJfycP/ygbKm036AsEZEwSr/QmZ+1IJxTOVN5i8jIILY79zwiL99RMlAL++ZG8= 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=XsQKAynZ; 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="XsQKAynZ" 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 46181sW3014026 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Mon, 1 Jul 2024 01:01:55 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 46181sW3014026 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2024061501; t=1719820916; bh=PBSMLOm5Po8X5BwRqt/ewbQVdKOLBiM1iMUfzgSaeE8=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=XsQKAynZfzx02V+lKhBtRhb5pwyLodkc9VWPdrFSU1ivU8o0L5t8TcMOgA3/ASIPG WnYEC7tMvBBtODiXwfjNFupzSOnuL7R+iYQDff/yutQG15niID5UQX+9xU5aRXvJSz kblOy019gXRmPniqGTvzicvmed6JqBIzX0TPQoPqZ5H7ZsSJhtBWun3ocVbfBbGgUk CSyJcpdlUo+f3MI2dtpOxseZ3v7OZEMp8ChbKrbpUF0+aY7+3cEqgt1uKM7AQ94ON7 43SJhs/fiMEhkmtFmDQ8YbPcOFsnkXXfgraks6G3MR0c5KX1ZhGuKiccbK7Vg9fCE9 uHKwVs0suHCFQ== Date: Mon, 01 Jul 2024 01:01:54 -0700 From: "H. Peter Anvin" To: Borislav Petkov CC: Xin Li , linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de, mingo@redhat.com, dave.hansen@linux.intel.com, peterz@infradead.org, brgerst@gmail.com, chang.seok.bae@intel.com, jgross@suse.com Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_v6_5/5=5D_x86/gsseg=3A_use_the_LKGS_?= =?US-ASCII?Q?instruction_if_available_for_load=5Fgs=5Findex=28=29?= User-Agent: K-9 Mail for Android In-Reply-To: <20240701064002.GBZoJPQg2IXSCRa4sN@fat_crate.local> References: <20230112072032.35626-1-xin3.li@intel.com> <20230112072032.35626-6-xin3.li@intel.com> <20240630160448.GAZoGCIHXRuBY8sLqW@fat_crate.local> <3A846C73-305E-4C55-B846-AC00657BA95B@zytor.com> <20240701060841.GAZoJH6XpJz6qyo-Lr@fat_crate.local> <38C69EA0-DB74-4D2A-ABB5-CB3F1D31FB0C@zytor.com> <20240701064002.GBZoJPQg2IXSCRa4sN@fat_crate.local> Message-ID: <2B27D0A2-B1D0-4347-8587-DCFDB05BF683@zytor.com> 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 June 30, 2024 11:40:02 PM PDT, Borislav Petkov wrote: >On Sun, Jun 30, 2024 at 11:31:42PM -0700, H=2E Peter Anvin wrote: >> Yes, all loads into a segment register are truncated to 16 bits=2E > >Right, but are we saying that somewhere explicitly or it is too obvious s= o >that there's no need to? > I don't know=2E It is stated in a number of places, but I don't know if it= is explicit in *this* specific context=2E