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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, 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 98F96C433E1 for ; Wed, 15 Jul 2020 18:04:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E72C20656 for ; Wed, 15 Jul 2020 18:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725992AbgGOSEO (ORCPT ); Wed, 15 Jul 2020 14:04:14 -0400 Received: from mga02.intel.com ([134.134.136.20]:13905 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725861AbgGOSEN (ORCPT ); Wed, 15 Jul 2020 14:04:13 -0400 IronPort-SDR: LbO8jKw5ZHl11eoddSiR1x2+s/pFVyY/vlu7wIZpVc36X49PhCg7KxW8SaB9baqmXpKc21EZ41 ULTmnGAeGamQ== X-IronPort-AV: E=McAfee;i="6000,8403,9683"; a="137374654" X-IronPort-AV: E=Sophos;i="5.75,356,1589266800"; d="scan'208";a="137374654" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jul 2020 11:04:13 -0700 IronPort-SDR: AFEfHv5iEkqe3m2mqnAPe003c26KBkwJz0CViX8toVUivl89IWg0iJNlJ1jpV8USflBvoWpZmC 1/iuUBAKXMiA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,356,1589266800"; d="scan'208";a="460181880" Received: from sjchrist-coffee.jf.intel.com (HELO linux.intel.com) ([10.54.74.152]) by orsmga005.jf.intel.com with ESMTP; 15 Jul 2020 11:04:13 -0700 Date: Wed, 15 Jul 2020 11:04:13 -0700 From: Sean Christopherson To: Pawan Gupta Cc: Dave Hansen , Borislav Petkov , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Tony Luck , "Gomez Iglesias, Antonio" , Andy Lutomirski , Peter Zijlstra , Fenghua Yu , Dave Hansen , Vincenzo Frascino , Josh Poimboeuf , Anthony Steinhauser , Mike Rapoport , Mark Gross , Waiman Long , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, Jonathan Corbet Subject: Re: [PATCH] x86/bugs/multihit: Fix mitigation reporting when KVM is not in use Message-ID: <20200715180413.GB12349@linux.intel.com> References: <267631f4db4fd7e9f7ca789c2efaeab44103f68e.1594689154.git.pawan.kumar.gupta@linux.intel.com> <20200714014540.GH29725@linux.intel.com> <099d6985-9e9f-1d9f-7098-58a9e26e4450@intel.com> <20200714191759.GA7116@guptapadev.amr> <20200714210442.GA10488@guptapadev.amr> <20200715005130.GE14404@linux.intel.com> <20200715171820.GA12379@guptapadev.amr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200715171820.GA12379@guptapadev.amr> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Wed, Jul 15, 2020 at 10:18:20AM -0700, Pawan Gupta wrote: > On Tue, Jul 14, 2020 at 05:51:30PM -0700, Sean Christopherson wrote: > > On Tue, Jul 14, 2020 at 02:20:59PM -0700, Dave Hansen wrote: > > > On 7/14/20 2:04 PM, Pawan Gupta wrote: > > > >> I see three inputs and four possible states (sorry for the ugly table, > > > >> it was this or a spreadsheet :): > > > >> > > > >> X86_FEATURE_VMX CONFIG_KVM_* hpage split Result Reason > > > >> N x x Not Affected No VMX > > > >> Y N x Not affected No KVM > > > > This line item is pointless, the relevant itlb_multihit_show_state() > > implementation depends on CONFIG_KVM_INTEL. The !KVM_INTEL version simply > > prints ""Processor vulnerable". > > While we are on it, for CONFIG_KVM_INTEL=n would it make sense to report "Not > affected(No KVM)"? "Processor vulnerable" is not telling much about the > mitigation. I know we don't care too much about out-of-tree hypervisors, but IMO stating "Not affected" is unnecessarily hostile and "Processor vulnerable" is an accurate statement.