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 837E6C388F7 for ; Fri, 13 Nov 2020 16:12:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45B9822201 for ; Fri, 13 Nov 2020 16:12:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727011AbgKMQMm convert rfc822-to-8bit (ORCPT ); Fri, 13 Nov 2020 11:12:42 -0500 Received: from mga09.intel.com ([134.134.136.24]:9889 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726701AbgKMQMl (ORCPT ); Fri, 13 Nov 2020 11:12:41 -0500 IronPort-SDR: 2JCoDOsGs5Ui6G3G+2dCVYHCJkBW34L6tlE2HLqKIt8tbtLiyYg+QVNQqkf6Und6ltFjiCHhtu 65kK4cz9bgYA== X-IronPort-AV: E=McAfee;i="6000,8403,9804"; a="170663097" X-IronPort-AV: E=Sophos;i="5.77,475,1596524400"; d="scan'208";a="170663097" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Nov 2020 08:12:40 -0800 IronPort-SDR: /EpiTz+ObiUYe2Tt61ei7Ih9ue4JXLvOFzFoszIGlTLqqqn3EIvramoTCldkoiD6eB957e0ac+ RaNWbkQmbfHQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,475,1596524400"; d="scan'208";a="309655009" Received: from fmsmsx606.amr.corp.intel.com ([10.18.126.86]) by fmsmga007.fm.intel.com with ESMTP; 13 Nov 2020 08:12:40 -0800 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx606.amr.corp.intel.com (10.18.126.86) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Fri, 13 Nov 2020 08:12:39 -0800 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx610.amr.corp.intel.com (10.18.126.90) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1713.5; Fri, 13 Nov 2020 08:12:39 -0800 Received: from fmsmsx610.amr.corp.intel.com ([10.18.126.90]) by fmsmsx610.amr.corp.intel.com ([10.18.126.90]) with mapi id 15.01.1713.004; Fri, 13 Nov 2020 08:12:39 -0800 From: "Luck, Tony" To: Thomas Gleixner , "Tian, Kevin" , "Wilk, Konrad" CC: "Raj, Ashok" , Jason Gunthorpe , "Williams, Dan J" , "Jiang, Dave" , Bjorn Helgaas , "vkoul@kernel.org" , "Dey, Megha" , "maz@kernel.org" , "bhelgaas@google.com" , "alex.williamson@redhat.com" , "Pan, Jacob jun" , "Liu, Yi L" , "Lu, Baolu" , "Kumar, Sanjay K" , "kwankhede@nvidia.com" , "eric.auger@redhat.com" , "parav@mellanox.com" , "rafael@kernel.org" , "netanelg@mellanox.com" , "shahafs@mellanox.com" , "yan.y.zhao@linux.intel.com" , "pbonzini@redhat.com" , "Ortiz, Samuel" , "Hossain, Mona" , "dmaengine@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "kvm@vger.kernel.org" , Marc Zyngier Subject: RE: [PATCH v4 06/17] PCI: add SIOV and IMS capability detection Thread-Topic: [PATCH v4 06/17] PCI: add SIOV and IMS capability detection Thread-Index: AQHWru2wVqYDq8zCAUGd/W1dOZWHUKmxA7+AgAAYm4CAABfkAIAAARAAgAQpOgCAAOGcgIAAphOAgAD60ICAAJaGgIAADwsAgAAFn4CAAuAFAIAAOXiAgAA79ACAABGDgIAAY1MAgAAHBICAAsnwAIAAVwYAgAC+sACAAGcnAIAAVyaAgABtcgCAAFeIgIAAPx6AgAEdLoCAAmDAgIAANQ0AgABC2gCAALXJAP//pWBA Date: Fri, 13 Nov 2020 16:12:39 +0000 Message-ID: <30928722afe64104b5abba09de4f74dd@intel.com> References: <20201107001207.GA2620339@nvidia.com> <87pn4nk7nn.fsf@nanos.tec.linutronix.de> <20201108235852.GC32074@araj-mobl1.jf.intel.com> <874klykc7h.fsf@nanos.tec.linutronix.de> <20201109173034.GG2620339@nvidia.com> <87pn4mi23u.fsf@nanos.tec.linutronix.de> <20201110051412.GA20147@otc-nc-03> <875z6dik1a.fsf@nanos.tec.linutronix.de> <20201110141323.GB22336@otc-nc-03> <20201112193253.GG19638@char.us.oracle.com> <877dqqmc2h.fsf@nanos.tec.linutronix.de> <874kltmlfr.fsf@nanos.tec.linutronix.de> In-Reply-To: <874kltmlfr.fsf@nanos.tec.linutronix.de> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-reaction: no-action dlp-version: 11.5.1.3 x-originating-ip: [10.22.254.132] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org > Of course is this not only an x86 problem. Every architecture which > supports virtualization has the same issue. ARM(64) has no way to tell > for sure whether the machine runs bare metal either. No idea about the > other architectures. Sounds like a hypervisor problem. If the VMM provides perfect emulation of every weird quirk of h/w, then it is OK to let the guest believe that it is running on bare metal. If it isn't perfect, then it should make sure the guest knows *for sure*, so that the guest can take appropriate actions to avoid the sharp edges. -Tony