From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from DM5PR21CU001.outbound.protection.outlook.com (mail-centralusazon11011003.outbound.protection.outlook.com [52.101.62.3]) (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 85A4F32FA18 for ; Fri, 10 Apr 2026 20:47:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.62.3 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775854037; cv=fail; b=pxemuEqnq7RkU3Ydj1t+cYobz2EEyxHNypvbcMi6h35OHHcazkyBr++409PnEVkLUwYZGrj5Oroiuw4g1qpjjpI2cZA0zGbeFtHCqF0EWkh+Ocvo+cn6gHCkmDR4/oeTDpu29pSBTx2MIYoYAIvAz3yaqmx+HX7mQDTLj6kwc68= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775854037; c=relaxed/simple; bh=IbUa/71pXZ9XVzS63TbTU6XvmekBYwfH2vd4W5tMRtk=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=dPSUagW1GA1EU80ooZ4PXs77UbyB6xWZDZGixtEG4NobD53nG+JM1zuanXbnC/Xs4jSfvrqcI2HuySXUKdLwZXd4RvPpeM1NuPQZcv5siTlKIpNUslzmICS7OG3O/MBrygnL80I8eoPIxXf3r1IH2BVrhMd878vmUj2BtgLxRU8= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com; spf=fail smtp.mailfrom=nvidia.com; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b=c+HISVjC; arc=fail smtp.client-ip=52.101.62.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=nvidia.com Authentication-Results: smtp.subspace.kernel.org; spf=fail smtp.mailfrom=nvidia.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=Nvidia.com header.i=@Nvidia.com header.b="c+HISVjC" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=fow8uCVlSFd9ZBpKeGEEhUCCeu5h2HyUfe1F1Hq27vGSKAKyrmiAZZKwc9l9QzbGbFXpxfzkNbNS+1jAuT8PpfiPJDvyKBBtPx45ssjB/rIouqoNDy0+ACCDslQio2luwL3gnxz7NBLY9j3vH21AgFKS/h5cEaY3W69Lr/Ml2yPAKMvBSgNohz1db5LZAGsbm+vjyMABVCZY5g8u8ey5AdYxkgb7mKp8xg4exMd9IvzFg3cCriix+jRNRaj0pnHpwMsOYphX6XtEv57j8Ck6w4lvOtiztrpmT7kWQxaMRqCOGajz9ahU/aJGFreKM6QLG7Jsts5xU8T+ax2WoFqYXQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; 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=rEQQyigO/wTt+/tUDbybbgXIm1ePzhWpR1zTorTkXS4=; b=JJK4IP/l5Y7/spD927497fTKMB7BZvVRbNDo9shIR6FGymXd0qJsEdifPdi1/KEHWq5qxzuaBrDL4FsZWHUgsphKsNOVugd176bp1FUtedrqVWwSoFvehuOltdcCDfituYK1hMhKi2ZrqJmq+FZ3mSqW3uEHUjjzvRiHTgproCNhS2Bt8yGg2LfknGhmOCFtB/e/eaWyunZCZLJybkDtveJPosCjzMFiUK42aaFAzPuNfFq5D/xz5eNlqceqkguu2BHrL6cHmGjpQYjDlFH5fYdbQJiM81PlKG/v48S1Vm9/8YDu2YHqrv1PSriqVkspuMkBY0H9Svs0hFtmCW8N0A== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=nvidia.com; dmarc=pass action=none header.from=nvidia.com; dkim=pass header.d=nvidia.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=Nvidia.com; s=selector2; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=rEQQyigO/wTt+/tUDbybbgXIm1ePzhWpR1zTorTkXS4=; b=c+HISVjC6Xq3HEnpnsSi2/4SK3KbLLjq2JzZaUCJZqJ+qYuEgbutaN7rzXh5VKT+p7J2uD76TQyMZn6DVTZAyiChWvWsQor4FrpX+lWquCohgH6UQ0pbDI2hE5UXJ2PmBof9Relfp0GR0koIpGf9i/IiJzvtnj4Twis5fKgsyxTmFjFaI4VgP7802ns3B9O9pvg6pRwQd8nY5uLuk7sMV0KTw5T9bxuI8MDE2HjtpQh1kvWv35PKS700tFn935yoxT+WmwgBha77drrIanuj3wYFCNSoJvsHH5JYIxFG462nU2Zt7YBnwu5aGA8OqTkJrM4qFX1ZXphDRFLJYvaX4g== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) by CYYPR12MB8964.namprd12.prod.outlook.com (2603:10b6:930:bc::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9769.42; Fri, 10 Apr 2026 20:47:11 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%5]) with mapi id 15.20.9791.032; Fri, 10 Apr 2026 20:47:11 +0000 Date: Fri, 10 Apr 2026 17:47:09 -0300 From: Jason Gunthorpe To: Nicolin Chen Cc: will@kernel.org, robin.murphy@arm.com, joro@8bytes.org, jpb@kernel.org, praan@google.com, smostafa@google.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, jonathan.cameron@huawei.com Subject: Re: [PATCH v4 03/10] iommu/arm-smmu-v3: Store IOTLB cache tags in struct arm_smmu_attach_state Message-ID: <20260410204709.GB2588311@nvidia.com> References: <20260409234223.GX3357077@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BLAPR05CA0029.namprd05.prod.outlook.com (2603:10b6:208:335::10) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) 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: LV8PR12MB9620:EE_|CYYPR12MB8964:EE_ X-MS-Office365-Filtering-Correlation-Id: 7c4ce79b-bf44-4329-6c91-08de974256c8 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|376014|7416014|366016|56012099003|22082099003|18002099003; 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:LV8PR12MB9620.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(376014)(7416014)(366016)(56012099003)(22082099003)(18002099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?T1LJ9Cqgmkw8dUpCJJvmXCEj99G7kwD7cprbXfASPhGqo0uTXYdJXBh35JGs?= =?us-ascii?Q?IXotCmZmacgcubm6/fzwTfN3kTKqTn7OGGcV4+sQVDf/sWVRotsFHxjdR0O4?= =?us-ascii?Q?Mqg6eXIJEpce+fG80SS0pOedNzJFvXXh0oMA77IOtkc4hkh2eotXPR0+/We0?= =?us-ascii?Q?kW1zsgUCJtXOvbr1MymBtLrz5C1BrQpudG7zdcIe5FlnYbb8ONUBnzQIOs+/?= =?us-ascii?Q?fD6zjgGe27QVZQYb+gw3/Mh6O85R+w+APavweOG14zF9CtvTpx5y3HTUwzJj?= =?us-ascii?Q?v4I6xG0Vvk4buazZtBDJtknFx5bkysa8SuNsEFTQxnWyfw5cPPrUI/bmX3Hd?= =?us-ascii?Q?Pelb7t2xMRX718NtPqHTk5PA2dSxiVkzXsDrGTMjyqtMXOoA60jsLXfUE4T6?= =?us-ascii?Q?uETGccXU0MWSbMglLxahca3706Q7JvK4BQtt0YflisLxpCJkahOPzIC/nNVg?= =?us-ascii?Q?xaCMiyW+yFb+c84czNuuXwSBRGvHf8BlkRt1Grue4eYKJTmAbQO17EQyU5vU?= =?us-ascii?Q?F+hhEdJr0mWweBUIkoEKWluIt5oc8uobX8w+H+yo1xW6bxYtrkqz13M8PHBh?= =?us-ascii?Q?FIgnZCpo8NpaprYXjdpYY9YJJW3is64iCpJAmXQ3oqi5LAe9LdcKxjXcoKaf?= =?us-ascii?Q?g75fg5FWCsTlcoZeZvMZO6jqE06amP4NIuF0QPZdfMOYiKsAL0hJynGzYVtz?= =?us-ascii?Q?9lKyPskKzqrFDIvH26vAJjurV1SiPcUk9WI5xNqFSyV9TVeUNc2ng6/4qhTU?= =?us-ascii?Q?rZe30W2flcHaecQvopHE9zzgvTkPXj4NV4yOwA6GwdsfjoJeNRU+Ndm0uZmz?= =?us-ascii?Q?WRh0kgn/9wZ5LQ16P3tvo5n+eg8kLkMjKvNhY0LWs8FKyJvNZX389uXSUaWB?= =?us-ascii?Q?qvhCdCvf1yzHxyFRr83PS8a0Jenj9W/9g+jHHVhxXMdFvP+CezJZ1+RdUXQQ?= =?us-ascii?Q?z3fDfV2h64EGOXKCsMPt6hmktdP6Q1sOx1LBmruTfWGE6rLviyJYwdu065Z8?= =?us-ascii?Q?M+kpyaXjk1w3dx+ALy5LgfTI3zU39xm8c5WfycgZpLJKPmowzfrJkm06SKnO?= =?us-ascii?Q?NDzSR2JJu0LXiCQ1fKLoFKX8aW1+bOl+AdHv3ZF3+rlvbcifjuR16ANGOqWV?= =?us-ascii?Q?lmeDxUrdQLbYbK3utGt2AaCWpTzTTN1QVYhMz9UewqyN9cDW/eCj0QRlc8NA?= =?us-ascii?Q?hwCWumxMSG7JuZQnWQcWQ+OyFzQ8ASOWxzagFDB1knpBVEBiyxM6D33YMKo+?= =?us-ascii?Q?NEAUoUbTlrz/oqEsW6OcyXxh52TB4k75X4j88t/rWCEUCByYhXpTCz1dc4nS?= =?us-ascii?Q?EnFhxtKGcuZ3Z0LJG7fBx6ZcPK9VsnW/no4SO+/8PwvZgM+BPp3NWo2u4UdT?= =?us-ascii?Q?lyMfktaKeVv+T5Wes2ghPg/v/Jr6LuKUClgTh6unFZoeMEQ6n7XXjfyJUkWE?= =?us-ascii?Q?4T0YAKs7hmW4yxq386lp7lI5yZD97BkN2m3WBt5T55eozHKLWd58fyRVxquE?= =?us-ascii?Q?Rk0luKR5XM1PFAvjbq+pj3EnBIXctneLywSxfjiX1OPTQMHXm4r0gO0lxu25?= =?us-ascii?Q?BaJPJqWerknv/UtxD7ZHqdbbo1i8d6yfedsIF+u+UZvn3k757hHpwQ+xOvYC?= =?us-ascii?Q?wwfnQFeV0U2HhBHWOyhysgRvrNCWwSbWTwA6JV7L7BBQ4rP3onwus3K6NBh3?= =?us-ascii?Q?6JytFvhXyYtOCm+I43svJKPQ1ZWKL1CMAMfSj5UW9Qobicmk?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 7c4ce79b-bf44-4329-6c91-08de974256c8 X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 10 Apr 2026 20:47:11.5692 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: D5rGd2aQhYAuGEX2b4Mb3NMkVE0iG2ZWTyavDl6eXhm13GJxQCCTzj1DKLnHMErS X-MS-Exchange-Transport-CrossTenantHeadersStamped: CYYPR12MB8964 On Fri, Apr 10, 2026 at 11:52:01AM -0700, Nicolin Chen wrote: > > Only readers *with the possibility of concurrent access* should be > > marked with READ_ONCE. IIRC this is just the invalidation walker. > > I added a cleanup patch to the beginning of the series and corrected > all the new reads/writes too. > > > Places like this have to be protected by a lock or the whole thing is > > wrong, so it should have a lockdep annoation. > > Hmm, is the lockdep_is_held() in rcu_dereference_protected() enough? Yes.. but I didn't notice it there, not where I usually look for lockdeps :) But also that should have failed in your testing in the SVA case, so make sure you test with lockdep on, and segfault some app using SVA to trigger the error clean up flow. > > But why does arm_smmu_mm_release() need a tag in the first place? ASID > > isn't going to be used when EPD0|EPD1 is set, so the tag can just be > > 0. Probably make a patch with that change early on.. > > I see. I added a cleanup patch. Also double check it still generates a hitless update, I think it should but worth confirming. Also is ASID 0 used at all? Jason