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 ; 15 Oct 2019 15:27:02 -0000 Received: from mx1.redhat.com ([209.132.183.28]) by Galois.linutronix.de with esmtps (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1iKOix-0002Cp-SC for speck@linutronix.de; Tue, 15 Oct 2019 17:27:01 +0200 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CC7572109 for ; Tue, 15 Oct 2019 15:26:52 +0000 (UTC) Received: from treble (ovpn-120-85.rdu2.redhat.com [10.10.120.85]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4907860127 for ; Tue, 15 Oct 2019 15:26:52 +0000 (UTC) Date: Tue, 15 Oct 2019 10:26:49 -0500 From: Josh Poimboeuf Subject: [MODERATED] Re: ***UNCHECKED*** Re: [PATCH v5 08/11] TAAv5 8 Message-ID: <20191015152649.yim4krwuttrh6xgi@treble> References: <20191009131251.GD6616@dhcp22.suse.cz> <20191014210458.GF4957@zn.tnic> <20191015103454.GW317@dhcp22.suse.cz> <20191015130627.7jkhqy2zrtm35ool@treble> MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: speck@linutronix.de List-ID: On Tue, Oct 15, 2019 at 03:10:33PM +0200, speck for Jiri Kosina wrote: > On Tue, 15 Oct 2019, speck for Josh Poimboeuf wrote: > > > Since all (or most?) modern Intel CPUs are vulnerable to TAA, defaulting > > to tsx=auto would effectively be the same as defaulting to tsx=off, > > right? How does this help with regressions? > > The mitigation is only needed on CPUs where verw doesn't have the buffer > clearing semantics. Can you elaborate? I have no idea what you're trying to say and how it relates to my question :-) -- Josh