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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 D0776C48BE0 for ; Fri, 11 Jun 2021 21:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEDAB613CC for ; Fri, 11 Jun 2021 21:37:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230028AbhFKVjU (ORCPT ); Fri, 11 Jun 2021 17:39:20 -0400 Received: from mga11.intel.com ([192.55.52.93]:25488 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229685AbhFKVjU (ORCPT ); Fri, 11 Jun 2021 17:39:20 -0400 IronPort-SDR: idi5OjpwaChbrxSejeuAXluS3XRoQ7TxMESJCdOOZix/rcebJ0Zkiamg+iZAZkUietKUQyvxaB f+6qp1hAa79A== X-IronPort-AV: E=McAfee;i="6200,9189,10012"; a="202590366" X-IronPort-AV: E=Sophos;i="5.83,267,1616482800"; d="scan'208";a="202590366" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jun 2021 14:37:21 -0700 IronPort-SDR: hdKBHocW4cw+bhpRa3+aukcMxVuVu4cR1A0degMe8prXywHn0vswyAprdKpmN2AzgF2DsA2YRq hjrBXjSYvIgg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.83,267,1616482800"; d="scan'208";a="449242177" Received: from gupta-dev2.jf.intel.com (HELO gupta-dev2.localdomain) ([10.54.74.119]) by orsmga008.jf.intel.com with ESMTP; 11 Jun 2021 14:37:21 -0700 Date: Fri, 11 Jun 2021 14:37:32 -0700 From: Pawan Gupta To: Borislav Petkov Cc: Thomas Gleixner , Jonathan Corbet , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , x86@kernel.org, "H. Peter Anvin" , "Paul E. McKenney" , Randy Dunlap , Andrew Morton , "Maciej W. Rozycki" , Viresh Kumar , Vlastimil Babka , Tony Luck , Paolo Bonzini , Sean Christopherson , Kyung Min Park , Fenghua Yu , Ricardo Neri , Tom Lendacky , Juergen Gross , Krish Sadhukhan , Kan Liang , Joerg Roedel , Victor Ding , Srinivas Pandruvada , Brijesh Singh , Dave Hansen , Mike Rapoport , Anthony Steinhauser , Anand K Mistry , Andi Kleen , Miguel Ojeda , Joe Perches , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: Re: [PATCH 4/4] x86/tsx: Add cmdline tsx=fake to not clear CPUID bits RTM and HLE Message-ID: <20210611213732.wdriyvmrkcu32fv7@gupta-dev2.localdomain> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org On 11.06.2021 12:06, Borislav Petkov wrote: >On Wed, Jun 09, 2021 at 02:14:39PM -0700, Pawan Gupta wrote: >> On CPUs that deprecated TSX, clearing the enumeration bits CPUID.RTM and >> CPUID.HLE may not be desirable in some corner cases. Like a saved guest >> would refuse to resume if it was saved before the microcode update >> that deprecated TSX. > >That corner case needs a lot more justification. Otherwise this is just >silly. Agree, chances of hitting the save/resume guest condition described above is low. I am okay with dropping this patch. Thanks, Pawan