From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F8FC8BFC for ; Wed, 17 Apr 2024 03:44:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=192.198.163.17 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713325492; cv=fail; b=reMhBRWm7yNdPqNRa8ikCu8E5k3IAIfA8w/9VQWZII3lcrSgOlVf1X7lRTBM/xFKfaBQ94IzBaDQiWqPyhSUGIPnmXcv8mAaxwkcXCg36DzvOoFavkfq2Tc6R12qYF+nNssfHHkknJhEr8+tZVF1C4oKTO1x3iZE9/gfwyR9kHE= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713325492; c=relaxed/simple; bh=5mf/1PkvdUWxcQgs1KJ0ev6A2CCzNzLlj7I/+gTTfV0=; h=Message-ID:Date:Subject:To:CC:References:From:In-Reply-To: Content-Type:MIME-Version; b=af198JO0ckY2k4fwCmUI2ZF87LlmelwJJ0E+WK8E9qZkjKD1+t/Jv2zdpx6ByiL9m7h3oOclT5qmDN0gxYnPqWxRNNkbaeYrqqyXFFz9dxk1sd3d2+RN7EpugMNvjM4x/Vtoip3omGCwJWXL4CUvbberWgChFl+d1xL1jGhwxt0= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=DRUjS+4w; arc=fail smtp.client-ip=192.198.163.17 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="DRUjS+4w" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1713325490; x=1744861490; h=message-id:date:subject:to:cc:references:from: in-reply-to:content-transfer-encoding:mime-version; bh=5mf/1PkvdUWxcQgs1KJ0ev6A2CCzNzLlj7I/+gTTfV0=; b=DRUjS+4wwgStERy2CVh9QF3JP3LPSN+zBfHFCNNx6oBZdlSB1dN1aDqZ UJCE4KCSOIJnwVL4UyLabqIN+mYmip7yoG6guhiKCe+8x4jZosmDW5KoD jCMDm/398f7T/LTEG7RKH7LbYQkq+xIbYu/GBLpj/VckJN8osYdpOSQ8T a0ny8GymvHhIKlgFaR5Px+IYAmfjJXLivngbTF1H9aSNiRdcz/TbldLA+ rioKf1EIpYHTCFI44bd23A9/CI3OPKoEEgi51uenY8TRODB9eN2QJPyCT /Gi1IIV5wRNNwKmL/cHhfis5ZjMdEwzH2LetpaP+kSIgU3hgCXihc/M5M w==; X-CSE-ConnectionGUID: gt7j2wlgQZ2gwsjy0qS4yw== X-CSE-MsgGUID: RR59o5roQGyFuEzpAAHTow== X-IronPort-AV: E=McAfee;i="6600,9927,11046"; a="8660540" X-IronPort-AV: E=Sophos;i="6.07,208,1708416000"; d="scan'208";a="8660540" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa111.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Apr 2024 20:44:49 -0700 X-CSE-ConnectionGUID: 6ei20DU0R7WieUrR33LolA== X-CSE-MsgGUID: o9jUbrR/RA+ejUxUlZaooA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,208,1708416000"; d="scan'208";a="22568765" Received: from fmsmsx601.amr.corp.intel.com ([10.18.126.81]) by fmviesa009.fm.intel.com with ESMTP/TLS/AES256-GCM-SHA384; 16 Apr 2024 20:44:49 -0700 Received: from fmsmsx611.amr.corp.intel.com (10.18.126.91) by fmsmsx601.amr.corp.intel.com (10.18.126.81) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Tue, 16 Apr 2024 20:44:48 -0700 Received: from fmsmsx610.amr.corp.intel.com (10.18.126.90) by fmsmsx611.amr.corp.intel.com (10.18.126.91) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.35; Tue, 16 Apr 2024 20:44:48 -0700 Received: from fmsedg602.ED.cps.intel.com (10.1.192.136) 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 15.1.2507.35 via Frontend Transport; Tue, 16 Apr 2024 20:44:48 -0700 Received: from NAM11-DM6-obe.outbound.protection.outlook.com (104.47.57.169) by edgegateway.intel.com (192.55.55.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Tue, 16 Apr 2024 20:44:48 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=HnuRttZvLXUV3OxMFGmGC8pQNIykKualfbN+gRdhWmvehOV4ngaySq4CraGCG5RbCMKxS9biht+9GZxvzk6Pa1Xm0/9LkfcvBWl3XiH11EvAa+g9lhv455oxOYgYfAubixqKhXd8TE9pqaYsHn6/qCiH/ZgNDIXS17LiR+QB4HqY7am0tUT56Fph4GMLsktdnUbUm6EnJuxqS55WNyHwQxrFC7EFSuqIQDPars+fzqxucn9LZHTK0NbdbmwmvAmxL9dDhPYJEmW2bh0Vp6/3eIKYWLJ0E2Kje6eG6Kbhpb0+/JzgY9+rCFQ0RJ296mPhgBG9OX1QtTTh1xsPvQDmQA== 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=BICXAmQzGrxYsGO8eVRqpnlOaGv2mLnKJzYTtvDSb3o=; b=Hkl37J44DO6qpYcbTHvFzcKs+iZ4kQECeXojKmr4UXSo6B5/UqifUqHIUig0E3KjvIgAxESaBiIRNA4eBkWy2i8ZWKnko4M2V+auR5CODD1DThpYjxlNnkHupgWb+x4LopucYBaGUBPaSPlJnnEsJAUQ7O/Ffw2YXCCqxpLpapciAbfRTROqN75xn0uamvck3NL1qsfvro+1HR+smVHNc4pCKuHWPSnaWCFDQ20sFD0SnYQ5iVhBSab1nVh/N3jz4Zl8Q2v3JIVuuLGPEmvfys2NC/NauE3BCIdtlnW0ILQ0viFTSXJneDjnvLf4eag8XlaYExBYBjQeH1AUO15rNQ== 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 Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=intel.com; Received: from DS0PR11MB7529.namprd11.prod.outlook.com (2603:10b6:8:141::20) by SJ0PR11MB4798.namprd11.prod.outlook.com (2603:10b6:a03:2d5::12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.7409.33; Wed, 17 Apr 2024 03:44:46 +0000 Received: from DS0PR11MB7529.namprd11.prod.outlook.com ([fe80::d244:15cd:1060:941a]) by DS0PR11MB7529.namprd11.prod.outlook.com ([fe80::d244:15cd:1060:941a%6]) with mapi id 15.20.7452.046; Wed, 17 Apr 2024 03:44:46 +0000 Message-ID: <1619eb87-3879-42c2-a2f0-6351dd504410@intel.com> Date: Wed, 17 Apr 2024 11:48:17 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 10/12] iommu/vt-d: Return if no dev_pasid is found in domain To: Baolu Lu , , , CC: , , , , , , , , References: <20240412081516.31168-1-yi.l.liu@intel.com> <20240412081516.31168-11-yi.l.liu@intel.com> <373e52b4-e663-4b2d-9a6b-feaf3a93892b@intel.com> Content-Language: en-US From: Yi Liu In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: SI2PR01CA0013.apcprd01.prod.exchangelabs.com (2603:1096:4:191::9) To DS0PR11MB7529.namprd11.prod.outlook.com (2603:10b6:8:141::20) Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: DS0PR11MB7529:EE_|SJ0PR11MB4798:EE_ X-MS-Office365-Filtering-Correlation-Id: 95a7ddf5-3638-4f5a-2927-08dc5e90b9a4 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 4RowpWKU52L353Lp3axUpwGG7+IVDNq9F4nY5GauuXiG+25ObrFxyDhaKtUbumbRoikYGbO+RPD0EBR5AVEXt/kazrIG37fWR5SAeA+O/VR8w0UKLdNsk48mKV9xHtZeDETkxEb4qb8ebKpNBMhCGajWqN5UxEADK+QYdEDTOnUaIed1hf5s1HR2nTztX7U10ia/RlFJOEodGse5XJOReRUc7DyNFQeglIOsovjlxB2sg1OfxHBD6YzEpZn6acQq3Q6nYY643ZsN5eH/+CxZukrfv2QObpof/EWgK/UVVUp1Igz8nAczitVMWjhTXJMsuDpdITdZP3KQNtUXa+1BCxDFslHz7+qhSODp58bLMB8xilRoM9w9e00pNWvjzzAQkb7V2ix41IEU7OCBzXL5XcBuFlgBvo0NgdDxspBEb8mydpSHqRhpTGPJqnVSKI9JuQmNJfIg2B0w0Y4kQaqMARfiKZ8WWPqNFRGBgBafI+ZFQztmLZi6SNQRPqSrxzYsap8KX+Qf+llbDhN1cD/KvDYtfgSGOs1To4orC638wBj+V2s293SiHy6B3u3zTnI/991aSE3srW8y58d45OpvlYTPUCEjOSP8eEgrB06f22mym8BihkJJoHmQOtfdWil/3c0BUkvqoZehd6FcoP7S5RUWHqYxmaMeSnBUDD2OlIU= X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:DS0PR11MB7529.namprd11.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230031)(376005)(366007)(1800799015)(7416005);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?VDk4NFVRU2dmdjdNN3MxOXBRWDNYUGF1anEyb2d0WkF6aG9wTlIva1hLcjd4?= =?utf-8?B?dUJsc2ExTFZlRTY5ajBVRmdpSlpDUGtwV210NGV6VWtqVVZCTHJBQXRoZE56?= =?utf-8?B?ZDdGbmtreEVkcHFUZkc4Z2pxc1J0MzY2YWh6RVdrNmU3ZUdBN1RuQ3lVdTZz?= =?utf-8?B?S3gvMkdyRWdqMkhaRFpUU00weVRxTWV2YXA5MU5nMkN3cjEwbEIyZmtoTWRi?= =?utf-8?B?YlFuNnBZWUtpWXZNd29rZndlMCs0YzRaYy9VQmJaMmUxdWFUWGU2aG92Wm9j?= =?utf-8?B?ZVJJQXlGNW14aHcvZFl4Q0RxK3V3NTRtS3hOVkQ5QTFJNWU2UkIyMDd5L2Rv?= =?utf-8?B?YVBsNWRzeWVMaUtheGJ2L0FtbDVjZi81OSt2MkNKS2FQZ3Zqb2dkaFVRZ0tK?= =?utf-8?B?NnRkWjQydEcxaXUxbnpkWVBjSGhTdStLOG1Ma21UeVhKOWVWVVVPWnZwcTB5?= =?utf-8?B?c0w3S0RtZVA4YnkrWTZ6UmlRaEhLN29iVWN2Rlpnemx2SyszcmFUaFZ2NGRp?= =?utf-8?B?cDdGRE1CTXZLL0o4aFlsWEllQlhBNmJ1VWtvci9zNXB3Z0I2dGtvYzNKL3Fr?= =?utf-8?B?VzNKRnRRejkwS0RlMjNKV05rblY4Vzc1TnZ6UUU0QjlYTTJ1T3NRTWljTll1?= =?utf-8?B?NS9GQkVRV2N0NE52bjRtMGkzKzlPbHlzYWd5Q3U5VHZFNXRSQTNMUXpNdjhx?= =?utf-8?B?a2xvTTVpOGxpZGNjRFlKeFkrKzNxY0RNR2RqZWVqWUNDNzJ3QTJsSkNzdGxj?= =?utf-8?B?S0duRzRYNkdSZlJPekZkdmdKQjRZaWNQdDgxMERjQVhXU0NtSmtQMVlPOXhV?= =?utf-8?B?cW45aHFqalVHSXc1SEZZN3lJUERNdk1ML2xYS2NEcU9kUThNdFFabXNTcjYw?= =?utf-8?B?b3B2eEEyblduRWR4WHhFWG1rNmpCaHVVYmVuT01aSmdZSThnWEZNeUtqaE5w?= =?utf-8?B?a2tvTkgwcmRDNWxtUUFNbjQxUWh4ZkN0UVhCMERZclBBenBKWjZsK05KRVJR?= =?utf-8?B?c3I3OHlYcnNGdUMzblBwcDNmaTVhM0l1ZDhJY1RDYmdXTFh2VC9lMkpVNmVB?= =?utf-8?B?WWw2dEZWOHBhcURkM0ZuWERiK0Y2ZjFpbFVzTFl1Q0Q4RWQyZGxuUzF2dDlP?= =?utf-8?B?WXR4dTFlSllDRmI0aHkxaG9jOW0rK0JVQk1pSEhST3pkQXRYM0lQM1k4K1dt?= =?utf-8?B?UDlyakRSKzRUK2xuK01xNU9NK05JdVpvRzY1OFpjS1J1ODhNVTFGSnlMM3Z3?= =?utf-8?B?NGVCNVE0enI2SHVGWEJnRSsxMCtCeXZaZFFpYWZiV0lodFI4OTE4WHdmOWlH?= =?utf-8?B?dXZhbjVRdHNkNlFWSG5MWFhGVWpjL1l3RTFsVkhLL3U0a3dIMktCWVB3WDQ5?= =?utf-8?B?OGswd3loMDRLL0lkb0RoNzA1WUVKMXdvb3krWUl4VkVrd1UxVlZuU1h1Qktt?= =?utf-8?B?TG1UTXdHVXVlbWplb21FdURjVlBURm9XMk1BMm1kSWtSdS9WOTYwbGdZUTNu?= =?utf-8?B?RUc3bFQ4WWhQNGd5NWtyRGU1OTRteE5jWDlTTVQ0dDlXK1lXRmFSYWpqQlhF?= =?utf-8?B?RzlKcER0a09IdHcxQU42YUphZGR0czVjdXdGRTRWQURkVFNId09FTzJLM0Ez?= =?utf-8?B?VE0vdUs3dDJUZE5oa2xYMXZoQWMwanRIeWMvL0NXYm5tNnpPSVZMektlVXRR?= =?utf-8?B?aXlHQzVqdDFoeG1XNUNCeEgyR2NSd3VhM1lQbjdjUHFkaldlVVh5UVowcXNw?= =?utf-8?B?RUg1ZUt1amd6elZ1MjI2MklVSUlkcDNjQXRkaHVyeVJzdXBGbjFRa2ptTGxy?= =?utf-8?B?NU9VQUkzTGZMb2UxZlNHdGxjWDF1dWhLQlVMMWNvbWRnaGVXam0zbFk3Zmx2?= =?utf-8?B?QzFvcDNqV2xrWGtlQ0orNzJkRTBnZGQ0ZlRIUkFDUHpsd2w1b1V5cWFRc2VP?= =?utf-8?B?UUM5UGYraGNNNlo0N045Vm4wZVpIczBmNG42eC82cTFIK3kxQ2Fobm9Bd3lC?= =?utf-8?B?b2ord3cwVGdaSnk0YzdCTkZ1cll4ZTRuWXE2VkUzM1Jnc3RsMWtIWEN5ZHA0?= =?utf-8?B?OXNtaGF0c2oxc2huUW5WcFFDOGNSL0lid3UxWTVGZ3BtSHVqdGFub2dQdEx3?= =?utf-8?Q?xXDHyJD7yoiDKyQpE8wV6srPc?= X-MS-Exchange-CrossTenant-Network-Message-Id: 95a7ddf5-3638-4f5a-2927-08dc5e90b9a4 X-MS-Exchange-CrossTenant-AuthSource: DS0PR11MB7529.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Apr 2024 03:44:46.3651 (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: 2+QTOdy2zqg/MDfjgOycO20bN5pNlXSsM8dGEu1XqNuyOLzOwbWhOjNFSn2ZHVp4+4StnWCYxYXzA85Q4agU3g== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR11MB4798 X-OriginatorOrg: intel.com On 2024/4/17 10:30, Baolu Lu wrote: > On 4/16/24 5:21 PM, Yi Liu wrote: >> >> n 2024/4/15 14:04, Baolu Lu wrote: >>> On 4/12/24 4:15 PM, Yi Liu wrote: >>>> If no dev_pasid is found, it should be a problem of caller. So a WARN_ON >>>> is fine, but no need to go further as nothing to be cleanup and also it >>>> may hit unknown issue. >>> >>> If "... it should be a problem of caller ...", then the check and WARN() >>> should be added in the caller instead of individual drivers. >>> >>>> >>>> Signed-off-by: Yi Liu >>>> --- >>>>   drivers/iommu/intel/iommu.c | 3 ++- >>>>   1 file changed, 2 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c >>>> index df49aed3df5e..fff7dea012a7 100644 >>>> --- a/drivers/iommu/intel/iommu.c >>>> +++ b/drivers/iommu/intel/iommu.c >>>> @@ -4614,8 +4614,9 @@ static void intel_iommu_remove_dev_pasid(struct >>>> device *dev, ioasid_t pasid, >>>>               break; >>>>           } >>>>       } >>>> -    WARN_ON_ONCE(!dev_pasid); >>>>       spin_unlock_irqrestore(&dmar_domain->lock, flags); >>>> +    if (WARN_ON_ONCE(!dev_pasid)) >>>> +        return; >>> >>> The iommu core calls remove_dev_pasid op to tear down the translation on >>> a pasid and park it in a BLOCKED state. Since this is a must-be- >>> successful callback, it makes no sense to return before tearing down the >>> pasid table entry. >> >> but if no dev_pasid is found, does it mean there is no pasid table entry >> to be destroyed? That's why I think it deserves a warn, but no need to >> continue. > > The pasid table is allocated in the iommu probe path, hence the entry is > *always* there. Teardown a pasid translation just means zeroing out all > fields of the entry. aha, I didn't make it clear. It should be no present pasid entry if no dev_pasid. Anyhow, I noticed intel_pasid_tear_down_entry() checks present first before going ahead. So keep going is ok to me now. >> >>> >>>  From the Intel iommu driver's perspective, the pasid devices have >>> already been tracked in the core, hence the dev_pasid is a duplicate and >>> will be removed later, so don't use it for other purposes. >> >> >> good to know it. But for the current code, if we continue, it would hit >> call trace in the end in the intel_iommu_debugfs_remove_dev_pasid(). > > The debugfs interface should be designed to be self-contained. That > means, even if one passes a NULL pointer to > intel_iommu_debugfs_remove_dev_pasid(), it should handle it gracefully. TBH. I don't know if it is necessary to make every internal helpers self-contained. It looks to be more readable to avoid unnecessary function calls in the caller side. :) -- Regards, Yi Liu