From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87475C432C0 for ; Mon, 18 Nov 2019 01:17:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FC9420856 for ; Mon, 18 Nov 2019 01:17:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="ETpnXcSd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726511AbfKRBRf (ORCPT ); Sun, 17 Nov 2019 20:17:35 -0500 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:30822 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726317AbfKRBRe (ORCPT ); Sun, 17 Nov 2019 20:17:34 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574039853; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=C80GHOjSj07/+Xd26qTeC94foICydtWFzbCqceMpQRo=; b=ETpnXcSdYE4CionkHcJriXydkmuSPYjaX4D79uWGEU2s+OGI6vfrA9zGz9+WSGIqcNvSGK b+V72xNIngMmMKt1NSOnhU3CM+oNPaHzoGQum8FXIPAwmzGWZ9ItK7VuM2gSU3F0KbBYni ldZOjinGNeqLZO5KinG2Db4VmmcygdQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-340-xc0IRqZfNDGa2iG2PR9Ztg-1; Sun, 17 Nov 2019 20:17:30 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DA98D107ACC5; Mon, 18 Nov 2019 01:17:28 +0000 (UTC) Received: from llong.remote.csb (ovpn-120-229.rdu2.redhat.com [10.10.120.229]) by smtp.corp.redhat.com (Postfix) with ESMTP id 62E1C1D7; Mon, 18 Nov 2019 01:17:27 +0000 (UTC) Subject: Re: [PATCH v2 1/2] x86/speculation: Fix incorrect MDS/TAA mitigation status To: Boris Petkov , Thomas Gleixner Cc: Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org, Josh Poimboeuf , Greg Kroah-Hartman , Pawan Gupta , Mark Gross , Tony Luck References: <20191115161445.30809-1-longman@redhat.com> <20191115161445.30809-2-longman@redhat.com> <7EAED44C-A93E-405E-B57B-89AC3F779A70@alien8.de> From: Waiman Long Organization: Red Hat Message-ID: <2fd3212a-915e-85cd-4be9-eb08b573382e@redhat.com> Date: Sun, 17 Nov 2019 20:17:26 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: xc0IRqZfNDGa2iG2PR9Ztg-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/15/19 3:21 PM, Boris Petkov wrote: > On November 15, 2019 8:35:54 PM GMT+01:00, Thomas Gleixner wrote: >> See the last sentence of the paragraph you replied to :) > Proves even more that this should be documented in *all* places that talk= about TAA cmdline options and we should not rely on references but write s= tuff out everywhere so that people can see it directly. > >> But serioulsy, yes we should mention the interaction in >> kernel-parameters.txt as well. Something like: >> >> =09off - Unconditionally disable MDS mitigation. >> +=09=09 On TAA affected machines, mds=3Doff can be prevented >> +=09=09 by an active TAA mitigation as both vulnerabilities >> +=09=09 are mitigated with the same mechanism. >> >> and the other way round for TAA. > Ack. > Sorry for late reply as I am out on Friday afternoon. On hindsight, I should have added relevant description to kernel-parameters.txt as it is the mostly read kernel document. Acked-by: Waiman Long Thanks, Longman