From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (193.142.43.55:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 24 Oct 2019 16:24:16 -0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iNfuI-0002bl-MD for speck@linutronix.de; Thu, 24 Oct 2019 18:24:15 +0200 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0C252B398 for ; Thu, 24 Oct 2019 16:24:07 +0000 (UTC) Date: Thu, 24 Oct 2019 18:23:58 +0200 From: Borislav Petkov Subject: [MODERATED] Re: [PATCH 1/9] TAA 1 Message-ID: <20191024162358.GB14115@zn.tnic> References: <845fbeac941c6a5f9f9bf588394497faaa694909.1571905227.git.bp@suse.de> <20191024152257.eftdgtffaak6cyvn@treble> MIME-Version: 1.0 In-Reply-To: <20191024152257.eftdgtffaak6cyvn@treble> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable To: speck@linutronix.de List-ID: On Thu, Oct 24, 2019 at 10:22:57AM -0500, speck for Josh Poimboeuf wrote: > This should clarify that not *all* TAA-vulnerable CPUs will get > IA32_TSX_CTRL, instead only the ones which aren't also vulnerable to > MDS. Added: "The CPUs which get this new MSR after a microcode upgrade are the ones which do not set MSR_IA32_ARCH_CAPABILITIES.MDS_NO (bit 5) because those CPUs have CPUID.MD_CLEAR, i.e., the VERW implementation which clears all CPU buffers takes care of the TAA case as well." Hopefully that makes it more clear. > > The other TSX sub-feature, Hardware Lock Elision (HLE), is > > unconditionally disabled >=20 > ... by the new microcode ... >=20 > > but still enumerated as present by > > CPUID(EAX=3D7).EBX{bit4}. >=20 > ... unless disabled by bit 1 of IA32_TSX_CTRL_MSR. Changed it to: "The other TSX sub-feature, Hardware Lock Elision (HLE), is unconditionally disabled by the new microcode but still enumerated as present by CPUID(EAX=3D7).EBX{bit4}, unless disabled by IA32_TSX_CTRL_MSR[1] - TSX_CTRL_CPUID_CLEAR." Thx. --=20 Regards/Gruss, Boris. SUSE Software Solutions Germany GmbH, GF: Felix Imend=C3=B6rffer, HRB 36809, = AG N=C3=BCrnberg --=20