From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linutronix.de (146.0.238.70:993) by crypto-ml.lab.linutronix.de with IMAP4-SSL for ; 06 Mar 2019 16:22:13 -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 1h1ZJ5-00084N-FV for speck@linutronix.de; Wed, 06 Mar 2019 17:22:12 +0100 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4F0AB30A81AF for ; Wed, 6 Mar 2019 16:22:05 +0000 (UTC) Received: from tonnant.bos.jonmasters.org (ovpn-121-197.rdu2.redhat.com [10.10.121.197]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B41E518E39 for ; Wed, 6 Mar 2019 16:22:04 +0000 (UTC) References: <20190304012138.gikabpafseh2swre@treble> <20190304012455.xi23xfddnexvdz2r@treble> <03c35306-dca6-9299-3db6-7396ba82674a@redhat.com> <20190304171721.e6qyv722i32ilza4@treble> From: Jon Masters Message-ID: <4dfc7ea3-ae98-50bc-aa34-20d191e84f77@redhat.com> Date: Wed, 6 Mar 2019 11:22:03 -0500 MIME-Version: 1.0 In-Reply-To: <20190304171721.e6qyv722i32ilza4@treble> Subject: [MODERATED] Encrypted Message Content-Type: multipart/mixed; boundary="3uxvq2GKeka2LSgoJ9QvTQy4K9GL6iZzC"; protected-headers="v1" To: speck@linutronix.de List-ID: This is an OpenPGP/MIME encrypted message (RFC 4880 and 3156) --3uxvq2GKeka2LSgoJ9QvTQy4K9GL6iZzC Content-Type: text/rfc822-headers; protected-headers="v1" Content-Disposition: inline From: Jon Masters To: speck for Josh Poimboeuf Subject: Re: Encrypted Message --3uxvq2GKeka2LSgoJ9QvTQy4K9GL6iZzC Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 3/4/19 12:17 PM, speck for Josh Poimboeuf wrote: > On Sun, Mar 03, 2019 at 10:58:01PM -0500, speck for Jon Masters wrote: >=20 >> On 3/3/19 8:24 PM, speck for Josh Poimboeuf wrote: >> >>> + if (sched_smt_active() && !boot_cpu_has(X86_BUG_MSBDS_ONLY)) >>> + pr_warn_once(MDS_MSG_SMT); >> >> It's never fully safe to use SMT. I get that if we only had MSBDS then= >> it's unlikely we'll hit the e.g. power state change cases needed to >> exploit it but I think it would be prudent to display something anyway= ? >=20 > My understanding is that the idle state changes are mitigated elsewhere= > in the MDS patches, so it should be safe in theory. Looked at it again. Agree. Sorry about that. Jon. --=20 Computer Architect | Sent with my Fedora powered laptop --3uxvq2GKeka2LSgoJ9QvTQy4K9GL6iZzC--