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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 34F14C33CB1 for ; Fri, 17 Jan 2020 13:24:00 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 04689206B7 for ; Fri, 17 Jan 2020 13:23:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GHcv3YJB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04689206B7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:57178 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1isRbT-0005y6-1G for qemu-devel@archiver.kernel.org; Fri, 17 Jan 2020 08:23:59 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:47778) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1isRao-0005Z8-AQ for qemu-devel@nongnu.org; Fri, 17 Jan 2020 08:23:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1isRak-0006t2-1J for qemu-devel@nongnu.org; Fri, 17 Jan 2020 08:23:17 -0500 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:59763 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1isRaj-0006nV-9G for qemu-devel@nongnu.org; Fri, 17 Jan 2020 08:23:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579267391; 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=9r27ABPOvVhS7P4SC5Jm3ZE+dkizbgXFevq5ijYW1Vc=; b=GHcv3YJBTeXoovoLaRURQ/rVxDprWu8AfKBX8vNsldL9Po28Cq7iy+14vdDuJoAVdEjPok t/+v61zjxH5WJXjGRrghRn72G3a5KCFV18gxU30e4itu4KPg5Y3Ts1axbvL/fSBbh7bm60 Xu5Sq61vh7ZhGTfVZ5LGQ6kIScymWXU= 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-41-OBakx1B3M4eOK1gpBgLd5Q-1; Fri, 17 Jan 2020 08:23:02 -0500 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B5DF08017CC for ; Fri, 17 Jan 2020 13:23:01 +0000 (UTC) Received: from paraplu.localdomain (ovpn-117-116.ams2.redhat.com [10.36.117.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6709460C87; Fri, 17 Jan 2020 13:23:01 +0000 (UTC) Received: by paraplu.localdomain (Postfix, from userid 1001) id BE8733E0489; Fri, 17 Jan 2020 14:22:58 +0100 (CET) Date: Fri, 17 Jan 2020 14:22:58 +0100 From: Kashyap Chamarthy To: qemu-devel@nongnu.org Subject: Re: [PATCH] docs: qemu-cpu-models: Document '-noTSX' variants and 'mds-no' Message-ID: <20200117132258.GB24159@paraplu> References: <20200116173639.28524-1-kchamart@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200116173639.28524-1-kchamart@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-MC-Unique: OBakx1B3M4eOK1gpBgLd5Q-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pbonzini@redhat.com, berrange@redhat.com, ehabkost@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Jan 16, 2020 at 06:36:38PM +0100, Kashyap Chamarthy wrote: [...] > (2) There are _three_ variants[+] of CascadeLake CPUs, with different > stepping levels: 5, 6, and 7. To quite wikichip.org[*]: s/quite/quote/ >=20 > "note that while steppings 6 & 7 are fully mitigated, earlier > stepping 5 is not protected against MSBDS, MLPDS, nor MDSUM" >=20 > The above is also indicated in the Intel's manual itself[+], as > indicated by "No" under the three columns of MFBDS, MSBDS, and > MLPDS. >=20 > [+] https://software.intel.com/security-software-guidance/insights/= processors-affected-microarchitectural-data-sampling > [*] https://en.wikichip.org/wiki/intel/microarchitectures/cascade_l= ake#Key_changes_from_Skylake >=20 > Signed-off-by: Kashyap Chamarthy > --- > TODO: > - I think I also need to add a note about 'tsx-ctrl' bit. Here too, > same question as above -- does it show up in /proc/cpuinfo/? While at it ... if I mention 'mds-no', then it would be inconsistent, and inaccurate, if I don't also mention 'taa-no' IA32_ARCH_CAPABILITIES MSR bit. In short, I should mention the following MSR bits, and their use, in context: - mds-no - taa-no - tsx-ctrl ... while bearing in mind that none (?) of these MSR bits will show up under /proc/cpuinfo in the guest, rather they're used to populate the relevant vulnerability file in sysfs (/sys/devices/system/cpu/vulnerabilities/). [...] --=20 /kashyap