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 16:42:36 -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 1iNgC1-0003n1-U8 for speck@linutronix.de; Thu, 24 Oct 2019 18:42:35 +0200 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id F009BAD26 for ; Thu, 24 Oct 2019 16:42:27 +0000 (UTC) Date: Thu, 24 Oct 2019 18:42:26 +0200 From: Borislav Petkov Subject: [MODERATED] Re: [PATCH 7/9] TAA 7 Message-ID: <20191024164226.GD14115@zn.tnic> References: <137b3a048af221bc7d9ea9a921359942b944204e.1571905227.git.bp@suse.de> <20191024153517.ysko4ni3dadqdzn5@treble> MIME-Version: 1.0 In-Reply-To: <20191024153517.ysko4ni3dadqdzn5@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 10:35:17AM -0500, speck for Josh Poimboeuf wrote: > On Wed, Oct 23, 2019 at 12:28:57PM +0200, speck for Pawan Gupta wrote: > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentat= ion/admin-guide/kernel-parameters.txt > > index ad6b69057bb0..e1aca10f2a7f 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -4856,6 +4856,11 @@ > > =20 > > on - Enable TSX on the system. > > off - Disable TSX on the system. > > + auto - Disable TSX if X86_BUG_TAA is present, >=20 > Not quite true, since MDS-affected parts don't have the new microcode > bits to disable TSX. How's this: "Disable TSX if the CPU is affected by the TSX Async Abort (TAA) vulnerability and microcode provides a special MSR - TSX_CTRL_MSR - which provides the required TSX control knobs. On MDS-affected parts where VERW takes care of the TAA vulnerability, that controlling MSR is not present and thus TSX cannot be disabled there." --=20 Regards/Gruss, Boris. SUSE Software Solutions Germany GmbH, GF: Felix Imend=C3=B6rffer, HRB 36809, = AG N=C3=BCrnberg --=20