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=-9.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MSGID_FROM_MTA_HEADER,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 A2E83C433EF for ; Tue, 7 Sep 2021 16:14:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B0A961131 for ; Tue, 7 Sep 2021 16:14:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233796AbhIGQPc (ORCPT ); Tue, 7 Sep 2021 12:15:32 -0400 Received: from de-smtp-delivery-102.mimecast.com ([194.104.111.102]:21778 "EHLO de-smtp-delivery-102.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232103AbhIGQPb (ORCPT ); Tue, 7 Sep 2021 12:15:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=mimecast20200619; t=1631031263; 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=LcbSHEuJ/n74+zmRLZEo33hTo1f5VMgflTIa8T0fZDo=; b=awOxYUlK1ZNufIwFjdxTMmqQAM3jdP9MYKCQ52OAXAic1RTyE7d3Haiv/dRnuXZfK+OptC nmi/xn7aUPerdG+kqbRnC6bh/LB++13qBa+S87eaPLFE/xd5F0p2Ft1cBpCJNOF2sKRYBw yU0tfPIG8oFBNnRIF3GLnofmTjhj/J0= Received: from EUR03-AM5-obe.outbound.protection.outlook.com (mail-am5eur03lp2053.outbound.protection.outlook.com [104.47.8.53]) (Using TLS) by relay.mimecast.com with ESMTP id de-mta-16-YfMEg0chOuetOUYREYE7pg-1; Tue, 07 Sep 2021 18:14:22 +0200 X-MC-Unique: YfMEg0chOuetOUYREYE7pg-1 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=O3x2M6ZNPBorl0v/ebyO/SUSa6mf94oeLXF8VSaWjisitGFKx+VnZOSNKsjdeK+OC8gssgIH3Ttl1UQcogKgGCqqQ55wppPCifo4NAZnBe0QovFu1L4bnMkC8+jjgaSK4uedNlZxj/ZJvcXPadD99Vwb0BMvUhtYksdm4XWeb2QaVHHDKq5GZcvT1/r+yV8YUw+nd7lokoJZQRl6TU5JKZ1zQ61NrPIMct5rp+oiHMqRODHvkrnG/Na2W6D/5Nm4RXfA6urjYvf5+wLnNMVOw6l1Q05eqGnagKOVCza2VWG8wmSWLsMbxMfVUEanRhaGuIvQcYQPogs5UpES9zJszA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=LcbSHEuJ/n74+zmRLZEo33hTo1f5VMgflTIa8T0fZDo=; b=hlECaybXcC4+Gqa0ZwV4tIXbyv1K0tcfdO0905bXclPl03sBWJcmqDkXofYLTXOiRZCev3CIIUjEWvaCGMgUx5itykjLU1t4uj3MH88agT3otTrO5HMq/hdDybDiIXoUQxsff0qlygti68A/W6WFnfr9lsEIZi49N9RTKQBnGzzAf9I49ITsZt6TEfTSz2Iqg6KeazRxE908KkzLP3V5XHt4K9ftHh2t1d2UfM3okwqUjBWq75LEtJ5GD2rneVlrOrX1il9gcbm9f9+sd9QVY0VI83KkeC4CMydYFbKyXn+pwb6uSJt/Eav8rwAixcpaJidFN+DKIEBIGHS7D2amOA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=suse.com; dmarc=pass action=none header.from=suse.com; dkim=pass header.d=suse.com; arc=none Authentication-Results: vger.kernel.org; dkim=none (message not signed) header.d=none;vger.kernel.org; dmarc=none action=none header.from=suse.com; Received: from VI1PR04MB5600.eurprd04.prod.outlook.com (2603:10a6:803:e7::16) by VI1PR0401MB2448.eurprd04.prod.outlook.com (2603:10a6:800:52::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4478.22; Tue, 7 Sep 2021 16:14:18 +0000 Received: from VI1PR04MB5600.eurprd04.prod.outlook.com ([fe80::4d37:ec64:4e90:b16b]) by VI1PR04MB5600.eurprd04.prod.outlook.com ([fe80::4d37:ec64:4e90:b16b%7]) with mapi id 15.20.4500.014; Tue, 7 Sep 2021 16:14:18 +0000 Subject: Re: [PATCH 10/12] xen-pcifront: this module is PV-only To: Bjorn Helgaas Cc: Bjorn Helgaas , Stefano Stabellini , "xen-devel@lists.xenproject.org" , Juergen Gross , Boris Ostrovsky , "linux-pci@vger.kernel.org" References: <20210907153017.GA741607@bjorn-Precision-5520> From: Jan Beulich Message-ID: <82a99bb4-85bd-61cc-85de-f8dd9d1f98ed@suse.com> Date: Tue, 7 Sep 2021 18:14:16 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 In-Reply-To: <20210907153017.GA741607@bjorn-Precision-5520> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-ClientProxiedBy: PR3PR09CA0027.eurprd09.prod.outlook.com (2603:10a6:102:b7::32) To VI1PR04MB5600.eurprd04.prod.outlook.com (2603:10a6:803:e7::16) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from [10.156.60.236] (37.24.206.209) by PR3PR09CA0027.eurprd09.prod.outlook.com (2603:10a6:102:b7::32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4500.14 via Frontend Transport; Tue, 7 Sep 2021 16:14:17 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 5aaa3d38-b7b0-47bc-14cd-08d9721a8b62 X-MS-TrafficTypeDiagnostic: VI1PR0401MB2448: X-LD-Processed: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba,ExtFwd X-MS-Exchange-Transport-Forked: True X-Microsoft-Antispam-PRVS: X-MS-Oob-TLC-OOBClassifiers: OLM:2733; X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VI1PR04MB5600.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(39860400002)(376002)(346002)(366004)(396003)(136003)(6916009)(316002)(38100700002)(478600001)(5660300002)(86362001)(26005)(53546011)(31696002)(186003)(2906002)(6486002)(8676002)(66946007)(31686004)(8936002)(66556008)(66476007)(83380400001)(2616005)(956004)(4326008)(36756003)(54906003)(16576012)(45980500001)(43740500002);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?NjBNdHRlVUI4VEZiYTJGUTg1dVcrRjMzalZ3WlNIN1FReStpTm5LbnQ1U1Nn?= =?utf-8?B?NlhjVENFM3EvOEhyenhiU05xaTI2eTlYUTl3WkFwTnF1VmNQenBMdS9UZU9u?= =?utf-8?B?VzFLNEJuZkhNTERWM1B1QWtyanBFa0dUT2Iyemx2aC9xS21YeFovcjRPTk5p?= =?utf-8?B?ZGRwNEpiY0ZzMFNxS1VxQ3J0WXMydm1OSUlaUFczWFZuUXo1Y2dkRkh0NVB5?= =?utf-8?B?emc1Q0ZuMmY3dmVqZmVPS3BVYUpOWGtKRmh4TzlrMmlhZ1d1RjFCL0xWMnpE?= =?utf-8?B?NUVGalU0OWx2clhveTFuQVptS0J5ZXNrYXpqajF6cmtpQlNPa1o4Rk4zTkNx?= =?utf-8?B?QlZwcjljLzZsQTJUb3NGaEw5Z0d4bjNvdjJMTWlLQ0Z4ai9ycG8xa240OVBF?= =?utf-8?B?Tmh4ZTBySktZYTJNVVJrMmFSdzdHaGhEZHY0UWZ2SXdFaVZ5aXd4QmU3Rndr?= =?utf-8?B?Tms5VStGbVFsTUNjTCt5bUw3SmwvcHRILzdKRjVxZXBrZHNxZDc5SlN0eDRR?= =?utf-8?B?Z28rTG1oWnlHUVhsQ1dhVHc0U1J3bjZYQVZ2a1ZNL3AxaEJybUZOcW5DQXZz?= =?utf-8?B?VldqWXBINjltVlZrYlJySFROb29wRjBZeThKangrWG9ZSE9ZSXB4RFU0cGxh?= =?utf-8?B?ZW1RM1RQelM3N3JLREt3WTFKdkNGL0NRWlYwbHMrK3o1cUtZM2NEdERVbDBD?= =?utf-8?B?QmJEZ1FxaGphVUgwaFE5NnJ1eUxScmtMekgzM3BtMFBpUkxhd3c3VjNaMGMw?= =?utf-8?B?ckhpdzF2Ui9TQnJQRFF6ZU9WdzRKaVRWMVIxMDY3UXlxOHpoQUk0YmhZWkp2?= =?utf-8?B?TDUwejBHbi9Lb0tIOE5QZDRjV3o3UEJvT3dHS1RJLzVXRFJyUnN6OUJyNXNB?= =?utf-8?B?VVBFRFpnc0FsLzhhK3EyMi8veG44TkJJUXloMVhTY0FocUtwdnpTSTROWVJN?= =?utf-8?B?SENGNSs2OEVWYUVaNFRSYVlLSW9qS051cU5qckJQTnZjZVZYWlhCZ2JGUDZr?= =?utf-8?B?MWVMdERYWk1rTTh0RE5KNzNuU2E0d1VnRjRrK1hkSkIra1lyNm1zN2xkUThU?= =?utf-8?B?U0Jtd1FhRGxGR1ZLeDNtKzNEcTI3SkNMZWRjTGE2bnkyaXZPa2FFc0U2N1lz?= =?utf-8?B?QTN6Rjk2VTRzVzh5WWNYUmI1WDkrckpkQ1hpM1FXZUcxRHRCUHNPQmVyYnFE?= =?utf-8?B?Y0gzVzVBUThVVnpUL1JyMitPYUVnTlZjQXZwWWg5c2VjZ2gwVnJkcU1pT2ZL?= =?utf-8?B?alZYaFJaa2JhcmpiR2ljMnRNU1hXejJRSlo5ang3M0dhdXZKcE5lUE01b3Zn?= =?utf-8?B?SGVWK2pWQk84bFE4Ukd4cXdDZXBiSUpxc0llSzRCb0FoQlpLZTlvTE95eGlW?= =?utf-8?B?aGxnSkNGRzRCSTVQc1lEeEdQM2FLNXNXakw1TWZPdjdMQktHeDFlN1JtQTN2?= =?utf-8?B?RzNXSG9Halp1MGNzNUVZd2lqeGxCRldTZXJpRXB1Y3FQN1ExUHBvV3ViMUVV?= =?utf-8?B?QlFGdHc2cTV0blkwb3pxemNCdW1XSGxuMGFXUmRZODJuQkJMemZDOUI4Y0ll?= =?utf-8?B?cWdOQmpRY1Jyc0E4Y1JCVjdES0E5bWE1dXV6K0tDajRLQ1d6ZENxOHJPSkZW?= =?utf-8?B?SER0by9Bd1ZKSjY1aktWQmpOUDdONjdpZDFTaXcwQVlmWmdpSFpiMXY4YVFK?= =?utf-8?B?MTh5Z25zM3EwcDYwV3ZVd25MVVpaT3c5Q055L085UDd3a3ZyWE82NWwxTFJJ?= =?utf-8?Q?uVv0HZ/5AMd9M47xGdt8+xVYzo0SEtzUVzXw9ST?= X-OriginatorOrg: suse.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5aaa3d38-b7b0-47bc-14cd-08d9721a8b62 X-MS-Exchange-CrossTenant-AuthSource: VI1PR04MB5600.eurprd04.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 07 Sep 2021 16:14:18.3962 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: f7a17af6-1c5c-4a36-aa8b-f5be247aa4ba X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: Pso7JENlOr8XTGDxqLt62uiVP6Bzb2jYhXKVqkYKWnLwQSThe9r8WdSzfRPA5JEpJJyUnTREAqf8EKvPoTNP6w== X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0401MB2448 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On 07.09.2021 17:30, Bjorn Helgaas wrote: > Update subject to follow conventions (use "git log --oneline > drivers/pci/Kconfig"). Should say what this patch does. I can change that; I don't think it'll carry any different information. > Commit log below should also say what this patch does. Currently it's > part of the rationale for the change, but doesn't say what the patch > does. "There's no point building ..." to me is as good as "Don't build ...". But oh well, I can adjust ... > On Tue, Sep 07, 2021 at 02:10:41PM +0200, Jan Beulich wrote: >> It's module init function does a xen_pv_domain() check first thing. >> Hence there's no point building it in non-PV configurations. > > s/It's/ s/building it/building / # xen-pcifront.o? The driver name is already part of the subject; I didn't think I need to repeat that one here. > I see that CONFIG_XEN_PV is only mentioned in arch/x86, so > CONFIG_XEN_PV=y cannot be set on other arches. Is the current > "depends on X86" just a reflection of that, or is it because of some > other x86 dependency in the code? > > The connection between xen_pv_domain() and CONFIG_XEN_PV is not > completely obvious. > > If you only build xen-pcifront.o when CONFIG_XEN_PV=y, and > xen_pv_domain() is true if and only if CONFIG_XEN_PV=y, why bother > calling xen_pv_domain() at all? Because XEN_PV=y only _enables_ the kernel to run in PV mode. It may be enabled to also run in HVM and/or PVH modes. And it may then _run_ in any of the enabled modes. IOW xen_pv_domain() will always return false when !XEN_PV; no other implication is valid. I don't think this basic concept needs explaining in a simple patch like this. Instead I think the config option in question, despite living in drivers/pci/Kconfig, should be under "XEN HYPERVISOR INTERFACE" maintainership. I realize that's not even expressable in ./MAINTAINERS. I wonder why the option was put there in the first place, rather than in drivers/xen/Kconfig. Jan