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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35FC0C05027 for ; Mon, 6 Feb 2023 19:22:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C20446B0072; Mon, 6 Feb 2023 14:22:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BD08B6B0073; Mon, 6 Feb 2023 14:22:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4A526B0074; Mon, 6 Feb 2023 14:22:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 960B56B0072 for ; Mon, 6 Feb 2023 14:22:57 -0500 (EST) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 5FF501609B6 for ; Mon, 6 Feb 2023 19:22:57 +0000 (UTC) X-FDA: 80437839594.18.1476E67 Received: from mga18.intel.com (mga18.intel.com [134.134.136.126]) by imf13.hostedemail.com (Postfix) with ESMTP id 0636420012 for ; Mon, 6 Feb 2023 19:22:52 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=B7z9+Zpn; spf=pass (imf13.hostedemail.com: domain of ira.weiny@intel.com designates 134.134.136.126 as permitted sender) smtp.mailfrom=ira.weiny@intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); dmarc=pass (policy=none) header.from=intel.com ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1675711373; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=MoUdKvY089v447fReOqxVgscrDRtMcX2KiKA6Zb656o=; b=rsFmsI8HItmUCFZfYFIuaD3aEX3tujgySzYgLOx5XudAmElx5gEgwHjtGHPzD8RoO04AG6 IqY5Ul8a57gwL5DgwQ742yTJX6EhLHlXh51tgehJFH17kU0+WhRW3OtfHMAC1UoDKTROwZ NtleCQGvqHEdA2LsiQJd1Ou2V5R9uls= ARC-Authentication-Results: i=2; imf13.hostedemail.com; dkim=pass header.d=intel.com header.s=Intel header.b=B7z9+Zpn; spf=pass (imf13.hostedemail.com: domain of ira.weiny@intel.com designates 134.134.136.126 as permitted sender) smtp.mailfrom=ira.weiny@intel.com; arc=reject ("signature check failed: fail, {[1] = sig:microsoft.com:reject}"); dmarc=pass (policy=none) header.from=intel.com ARC-Seal: i=2; s=arc-20220608; d=hostedemail.com; t=1675711373; a=rsa-sha256; cv=fail; b=ZYXeGM+fAT2r08QjnmoC/2Dp0Ktkpjk0onaZVPW9mA1y51hrLyAD57YQxpcoV5bS7Cjpmh Aq6ztSv09SyAAX7c3BwQS1kz42tHRD4nEZNaQljgQ/i11erO4wmxasggyhh3M0ap8HBvtx OCOsQ5VotWXdpbOfl/8/QNyWbyV8AR0= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675711373; x=1707247373; h=date:from:to:cc:subject:message-id:references: in-reply-to:mime-version; bh=+vD79+JXwxgmc+oQofpUVAR76ttTQIW4yi/+4uEsTnk=; b=B7z9+ZpnQjL4Psq+SW9Ao+hdSRqJFPrrnNBu7AcMsVXE+KI3Kl3IIQs1 Ib0BcEcEYpLyLNpY0MdtTISWAryY1O0fW7klsjI1qpBa3glne8G6fiqMx WUOztXH3bb6V2i+GEe0oZ6ZgLwLmC298Yom0cebf/u5fI8bRtxRlCnWZm vBajSKnSXuTnUMr6q7DuyG767WWT4R4qjYjpqHSNG6lTskt/pEyBylgDp 7xEJyFirV37JGHtp3NlPQ7iULp+uZnoSXehUsgZWgqASI9NplyHNjonp8 W6ovuzSUhhIyDcvjY4Vhbx1p5r2VygjuuL2aA+QJZeN/G9GU8OoS2RVfz Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10613"; a="312949166" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="312949166" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2023 11:22:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10613"; a="616540196" X-IronPort-AV: E=Sophos;i="5.97,276,1669104000"; d="scan'208";a="616540196" Received: from orsmsx602.amr.corp.intel.com ([10.22.229.15]) by orsmga003.jf.intel.com with ESMTP; 06 Feb 2023 11:22:42 -0800 Received: from orsmsx611.amr.corp.intel.com (10.22.229.24) by ORSMSX602.amr.corp.intel.com (10.22.229.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16; Mon, 6 Feb 2023 11:22:41 -0800 Received: from orsmsx610.amr.corp.intel.com (10.22.229.23) by ORSMSX611.amr.corp.intel.com (10.22.229.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16; Mon, 6 Feb 2023 11:22:41 -0800 Received: from ORSEDG602.ED.cps.intel.com (10.7.248.7) by orsmsx610.amr.corp.intel.com (10.22.229.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16 via Frontend Transport; Mon, 6 Feb 2023 11:22:41 -0800 Received: from NAM10-BN7-obe.outbound.protection.outlook.com (104.47.70.105) by edgegateway.intel.com (134.134.137.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.16; Mon, 6 Feb 2023 11:22:39 -0800 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=OjTaOmFdBNuOa7psWkfUpoUDoYekIsskZf9jgJt52fz2Qlh0xMUjoVFWJ99eLx5bb1LkmjZl2bNb7QZEHXekPjCU2CRBekjrpnG5Gbp/K7ETK7oL5paaWkrgZnaFVaD5aTOsZadPSr4/4kdyEIXcLHKoORLj+2a0G04HAiIKWmE0XaJEW6iNZvtdUIRu5EDTZEk8cyURY8MsGO9EjG8dhVOqiA6ekeJBY6ZJLJrcN/ORyLqgWeW9b/2AQ367QJSLHIc5StWkQytvGQffuPJ5q1I0RepXy26OYOXGR+70FTT3UWE/koetNlnCNXvZQl/1J7KwaVPDKi0fDGrfFw6ZJw== 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:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=MoUdKvY089v447fReOqxVgscrDRtMcX2KiKA6Zb656o=; b=T0NPS8e/Zawv9zsUakMmQgKH/sbWKuP7YBglD/Juhp6q31uSC2ZO/1QYWl68a9Ii7H4BrjuidkHJNLPoBG4eMNbY3qHa8s421ET2ezH+RMYm/vACRPLoJAMt4+BEoaPDjVnw8Vj4o5diEPSxuZ1xvylBy+7Agji4o7NzRBd10sOqc5mvaAg9KCbLdzdbFGZmUqR4Sq2SYXSCeE8Y4URBn2cXOMuLsR3CizZ8Fj/w/DiXzf81RgI2s/lh7y1XzEVm3ZI0euncKFMAR4waJPFaLrT3qau5NN5e/ntEo4L072ASsXggeLwN8pCxQ9o9GLzN3dzleMHfHQG0iMllS9o0+g== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=intel.com; dmarc=pass action=none header.from=intel.com; dkim=pass header.d=intel.com; arc=none Received: from SA1PR11MB6733.namprd11.prod.outlook.com (2603:10b6:806:25c::17) by DM4PR11MB6118.namprd11.prod.outlook.com (2603:10b6:8:b2::20) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6002.13; Mon, 6 Feb 2023 19:22:38 +0000 Received: from SA1PR11MB6733.namprd11.prod.outlook.com ([fe80::6851:3db2:1166:dda6]) by SA1PR11MB6733.namprd11.prod.outlook.com ([fe80::6851:3db2:1166:dda6%9]) with mapi id 15.20.6064.034; Mon, 6 Feb 2023 19:22:37 +0000 Date: Mon, 6 Feb 2023 11:22:35 -0800 From: Ira Weiny To: Dan Williams , CC: , , Subject: Re: [PATCH 03/18] cxl/region: Support empty uuids for non-pmem regions Message-ID: <63e1537b2202_fa3292942c@iweiny-mobl.notmuch> References: <167564534874.847146.5222419648551436750.stgit@dwillia2-xfh.jf.intel.com> <167564536587.847146.12703125206459604597.stgit@dwillia2-xfh.jf.intel.com> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <167564536587.847146.12703125206459604597.stgit@dwillia2-xfh.jf.intel.com> X-ClientProxiedBy: DM6PR08CA0031.namprd08.prod.outlook.com (2603:10b6:5:80::44) To SA1PR11MB6733.namprd11.prod.outlook.com (2603:10b6:806:25c::17) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA1PR11MB6733:EE_|DM4PR11MB6118:EE_ X-MS-Office365-Filtering-Correlation-Id: a08d85a1-2395-45c4-5cc9-08db087781e4 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:SA1PR11MB6733.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230025)(396003)(136003)(346002)(366004)(376002)(39860400002)(451199018)(186003)(41300700001)(44832011)(2906002)(4326008)(5660300002)(66946007)(66556008)(8676002)(66476007)(316002)(8936002)(6512007)(26005)(9686003)(6506007)(6486002)(478600001)(82960400001)(83380400001)(86362001)(38100700002);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?0n2px25OCP/Sc6mAV5l4GP/A577ItXWoLekUQ5FmXLhNyKnwzqPeYPJquPkP?= =?us-ascii?Q?suM2U0RlEDJ4wAydV8TLnyFl492DbprOKTDgqrw7HGcYo2KzG1yT9yO2PJoX?= =?us-ascii?Q?z5NnYZooBRD2E4OEyQTyXHGkbqg25oOJWKE6UTUF+jg04AEOvmUaGxuKbH/M?= =?us-ascii?Q?qq2Wz3hWARsRX/PoDzXHco6340k77LkDaAYC6kE0VKRJhwphAHk791+CiWYI?= =?us-ascii?Q?huAXgxitkM9m5qkcGsFkku8TyTnKHVnAtruKoEBV3pPr9KrTFRexpUJZu1Dm?= =?us-ascii?Q?bfDFpl6fz6MYa4eT9a0udybvpo1uoPncybV3mELJFUGT4nN0RwMUy9x4ukux?= =?us-ascii?Q?xCUwyeJQIynbJC5i3Pex7doi0OJEU9UUJOQDR78b7B6sFgaod1UzkAwLfIWn?= =?us-ascii?Q?iPiF44Aj7XeyOvnpZSPGOQvkkVzwjsQojmwB2kZLMcyYwspU8rsCDH3hB33J?= =?us-ascii?Q?Z9agAkc2mDkvJstkt6CDXS+Kdk+fHX3AALRfZtPrbYt451LSflwkPWc71Wcv?= =?us-ascii?Q?qIzQYLj3D2iFXmTb6+Ll0ZLCLIqD640cw3uRc4L9oS8YzMwVUIJuSsTha1En?= =?us-ascii?Q?094pmWGHgEZh5hl0sCuVGlHbjtpUDZoyJ3aa080WN0wj26pj+2VsjOXKZ5Pt?= =?us-ascii?Q?rQYmLpMj0z5LdG70x/15uvvKH8PIOgABAzMMn7Y/uc2JzzPi8ye4nQx/51BG?= =?us-ascii?Q?q8isvcyQEIwqvdG+8Ei8ExdDuKNbAcxLsWfgll73iSJsOGaZN52/lheKuWek?= =?us-ascii?Q?FECHUn4wlQa9cH7TZGHDM2bYX4wlA6Ql0PZlNhs7PDjpoPwCABc3TTWQ3AqZ?= =?us-ascii?Q?iaSkQGqhMzWgSWg9hCLbUl2dXkCIocm8y9+0UFtHjk/GpqG+EiTJ2XWhmVsZ?= =?us-ascii?Q?v7QWVVljNqUI7Zr1D0FcIXkqd6gEg+uB6U/t4xpSziQvy4N+p7Ou+2MY9QJj?= =?us-ascii?Q?E5Q+lKC5yEQab6sJHsCGzUjnt+J8q1/Cwu0/4Oud1wwKt3eTH5LChIpFf4fo?= =?us-ascii?Q?efflq5er33QAXZec139PzOINAZynmLS2RayD+45RE4vQIv1juSIaDo5KfnEB?= =?us-ascii?Q?er6UW3tIwbIqPO8Zsnqgrk5/MoCp+aXenGoAeojVMqu5uZIJ1yMCpW3unBvc?= =?us-ascii?Q?jF3VznJWOKmtq41TCQWF+vzPdjcdzNej+OTzGU7QUA99dx3SLbaY3cF1y9hW?= =?us-ascii?Q?gTa72+OofYV0zatm/OfONIY//bZG0RmTCxENcX3xn8r6kTboDjzGkBLrdaaT?= =?us-ascii?Q?JrPQFRbHPDHdOp+lKsu1jGJU2F9WxrJJ1Vj6oMA+Yc9elbZAZlT7e4kZhPTV?= =?us-ascii?Q?uIk7Bx3tIJg0ZOmdqSFN7DVCSYEvOzaf5cHF5Akg7J74aTHNDide6VuKXDFK?= =?us-ascii?Q?dUB11Zjf0xcEVc68i3F7IButiwP+g7mGxtPK+xL0BsJ8Aw3M2Z+UCHVXDGae?= =?us-ascii?Q?1Qsdad6MpszqmQIilaBptmWL1TXhLzN1y70nIFzkzSQVT84YJd2ZrpIb1tPo?= =?us-ascii?Q?WO11myt+02tFc/Ofb8f+eshx8Ye4V1+/iaHvP4I8BAIHh9qwKtR5NHxvY9Ri?= =?us-ascii?Q?Lmmibhy7Kt6NeXF5dlsmiHNGknjsElwstcvFsY7D?= X-MS-Exchange-CrossTenant-Network-Message-Id: a08d85a1-2395-45c4-5cc9-08db087781e4 X-MS-Exchange-CrossTenant-AuthSource: SA1PR11MB6733.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Feb 2023 19:22:37.8470 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: g/xlwljxG4OxQ/8qPXtUFO0p8ImYNlWxp5rtS12RguGtVh7rNU7p2V2ekkSB1ZqAvAAKI9aQ4l7iYYNkJQPtgw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM4PR11MB6118 X-OriginatorOrg: intel.com X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 0636420012 X-Stat-Signature: ux5tdwfqfyjsigxsuudcgg8e9i1eyu8q X-HE-Tag: 1675711372-908491 X-HE-Meta: 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 eeX6/Ou7 h1URcB4DB/cMRUpIQyaFZvlyaX0kFHT52vcM4bG8W4fwu0fOeRIBjRYwDysRLERnvmn78DYkd9c6xHHilnji4DrXRdbKBm5qgWZt9lQMNOYGmpS6nC/Dve4DjCcOrMt++ZqRyqBRukoF+i5dSQqjT9ePn3CW/NZKpOORlPD7iq5VsJZM9qcBGgAEex2+85VB1mHXhC1Mr3X0PzTW5lBleYN+5xBW0qlhUCtHPn2Wm3hInjVwj/5WljVr1hSxku+8QcPmExCEvZ0Y5FwGQUJjXm/xI+uvp0qunkRWyp5fFpZjMYEVXuSozwcBlaS3VA9rVPnWG8y21yteYaS1NcoE94AX+Reekt6GnxEd4h3YM8C+9aRE= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Dan Williams wrote: > Shipping versions of the cxl-cli utility expect all regions to have a > 'uuid' attribute. In preparation for 'ram' regions, update the 'uuid' > attribute to return an empty string which satisfies the current > expectations of 'cxl list -R'. Otherwise, 'cxl list -R' fails in the > presence of regions with the 'uuid' attribute missing. Would this be more appropriate as a change to cxl-cli? > Force the > attribute to be read-only as there is no facility or expectation for a > 'ram' region to recall its uuid from one boot to the next. This seems reasonable. > > Signed-off-by: Dan Williams > --- > Documentation/ABI/testing/sysfs-bus-cxl | 3 ++- > drivers/cxl/core/region.c | 7 +++++-- > 2 files changed, 7 insertions(+), 3 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 058b0c45001f..4c4e1cbb1169 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -317,7 +317,8 @@ Contact: linux-cxl@vger.kernel.org > Description: > (RW) Write a unique identifier for the region. This field must > be set for persistent regions and it must not conflict with the > - UUID of another region. > + UUID of another region. For volatile ram regions this > + attribute is a read-only empty string. > > > What: /sys/bus/cxl/devices/regionZ/interleave_granularity > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index 17d2d0c12725..c9e7f05caa0f 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -45,7 +45,10 @@ static ssize_t uuid_show(struct device *dev, struct device_attribute *attr, > rc = down_read_interruptible(&cxl_region_rwsem); > if (rc) > return rc; > - rc = sysfs_emit(buf, "%pUb\n", &p->uuid); I guess it all depends on what p->uuid is... Shouldn't this be all 0's for a ram region? Does sysfs_emit() choke on that? Ira