From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 2002:a17:505:a0c:b0:1be9:327d:8ee3 with SMTP id cg12csp4253053njb; Wed, 11 Dec 2024 10:01:35 -0800 (PST) X-Forwarded-Encrypted: i=3; AJvYcCUT+6BQWCO6o5z3igWtuIIID4lGL+vsbVxsxF2uf9h7J3BtUXkhchpZAl2kbmcNwyjYsQt+tFyzSUq6YQ==@linaro.org X-Google-Smtp-Source: AGHT+IGyqDFpLZwvLEV9nUuxNpKFrBrO19tnWCjLbsTG6MI4MZnjUp+Ij1dMOS+12fivp/qXG9ID X-Received: by 2002:a05:600c:3b11:b0:434:9dfe:20e6 with SMTP id 5b1f17b1804b1-4362285f8f0mr5778785e9.23.1733940094930; Wed, 11 Dec 2024 10:01:34 -0800 (PST) ARC-Seal: i=2; a=rsa-sha256; t=1733940094; cv=pass; d=google.com; s=arc-20240605; b=BcR6ijKIIgJ5lFw2NR3qOXuHI8u2mH4eZCLczXXaU7Mk8Y58yMIDDmCwc3jHzaXXwC 5YcktEI/EyH19OTgkqMKplSzcHaY3l5m9HQhCNU/b9yAbyyTp96j/ojsJApXpOr/w/uE NRW3qtE4zNy7xj6PVr7kymSFg2UhVc1inwobbPKdff0PLdf1U2okQBX34/eytsUplaRF h6jkU8pQS/CLAMbJ3oUyk+YN982l68HltAvkhGLK9ZNSiESefCr6iwKTQ2NuSm9Vm6Jr fEIY6lk+YiAWELKyJNzFcYGzMDmqUonSHzbodfa2WLH/EX2BcpqlggBCTPoGS7efj9w5 uKAA== ARC-Message-Signature: i=2; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20240605; h=sender:errors-to:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:mime-version:in-reply-to :content-disposition:references:message-id:subject:cc:to:from:date :dkim-signature; bh=dVHsGdHVeuSjkexTKVTx0T5w5Mem6zy9WMEuIyWEfSY=; fh=SZkuCfDVGPBKhhlzV/eRZfjwR1k1Q+TmVkeXhqW4UUs=; b=Dqv0Zx0SdIJc+RyHiTncmTsGUaaWWjptV5ngyElpn5/oxXkuPLWLNgtjLOHRMtP7q8 N1mzRx46SygMhXOpMuk0uAN9uYkenuj5Co2fdGiejCw1q+km5zhDoPYXa3tH4+brtC2Q XC5vTuZjv0bUZ7U2LB+usMqm9uF1CflCi3HHlEfVSeNtlYZZYT7/ecGp6TyWSKSDbzOw Vx9qFxojasb2/f+1/upYLkPnjyVht4N7c8osfmd3ZYmsRpUuhbZ69JDFzbKM6yiDk11B zLN+qmpgx2art2p78l4K0u4ezZnZiTbScmY+lUp40K0HYJ0G1iucSaPw6tW7NAsSAbNc qjrA==; dara=google.com ARC-Authentication-Results: i=2; mx.google.com; dkim=pass header.i=@Nvidia.com header.s=selector2 header.b=pqSDOZYX; arc=pass (i=1 spf=pass spfdomain=nvidia.com dkim=pass dkdomain=nvidia.com dmarc=pass fromdomain=nvidia.com); spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org"; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=nvidia.com Return-Path: Received: from lists.gnu.org (lists.gnu.org. [209.51.188.17]) by mx.google.com with ESMTPS id 5b1f17b1804b1-434da0d4686si83612435e9.24.2024.12.11.10.01.34 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 11 Dec 2024 10:01:34 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; dkim=pass header.i=@Nvidia.com header.s=selector2 header.b=pqSDOZYX; arc=pass (i=1 spf=pass spfdomain=nvidia.com dkim=pass dkdomain=nvidia.com dmarc=pass fromdomain=nvidia.com); spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org"; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=nvidia.com Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tLR1Y-0005my-CL; Wed, 11 Dec 2024 13:01:24 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tLR1V-0005mV-OS; Wed, 11 Dec 2024 13:01:22 -0500 Received: from mail-bn7nam10on20624.outbound.protection.outlook.com ([2a01:111:f403:2009::624] helo=NAM10-BN7-obe.outbound.protection.outlook.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tLR1R-0004n9-J2; Wed, 11 Dec 2024 13:01:21 -0500 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=MuLfPxEUFmzXP/37c0K75repNjlMJWtw8MVwer3sty74NaQdmPYt04ECo/l12LJTYbdgivxp225rczhIoQxfolwNgCiMT6g2X2iUN8X3fHvz/KPNyPP4uo9QhM7I+cEtGvrXLX2KAKkOg7XWxZEELuNMqbLUWhWhDzVi5yjglfQQAoaXWmKdW8ZZBm4SD96pK0G59dREw0hXSLaAGJNBFmhLeZiNLBBLEEwqeYdJH71QZaMql/WZqfQrq1cNVBflYosHgBwyRItOu9EciIcZ9n0gKE+cSuYav93kUElqiRyCfDIf5nctl0XPcVtmJPOGUerzziCCRxV7hRt+l3Etzw== 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=dVHsGdHVeuSjkexTKVTx0T5w5Mem6zy9WMEuIyWEfSY=; b=W+S10NRhHEFvPxAHY++FTgF65r9MtvSxZMZA9JuX0KhZV3KIWBWje88o4facP9hIvQfmT+moei6yZHbl9/kK+xdrnGogEkROoj6zElqYkB0yXjwuFrOZPr99+vxKkRCBH+y91zRfPa7N6xakDbIwySkEd0Joi7whbGRJRII8HlGYWvtmvylg8uvq6WNXD247v/c0MwICXDlc4HMS4wUr7jg7KGubkt1iZMkdYgxQvPzVA2XoW888SExl6gTx2ANr9s2ZM4Vvi79z+5QXdvrKnLTb8hj9vZH7oXIQBw/g90/Gg8uylcCKgkwtCb+at5E/xlc91JTnGNoa0EiM1ukkgg== 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=dVHsGdHVeuSjkexTKVTx0T5w5Mem6zy9WMEuIyWEfSY=; b=pqSDOZYXjtnz8Q5+BHD//b/PPkjet+OuO+SmYZO0Di6Lx28cAOk+T2/AGCA2yms0zvUU+bQUq4f8F2QS0hekjcgU7R9JOyZOfOG/TIzWZhUimIQ5Jq1X5Mb4Ey9bgltoRy3/9pQSCLnPtBRrtRPRaH+ux0KxvJCZxwwDuvj1/kmxKjynDOP4gslOfWjParkrH/X7WR+1CusQ3/IyDfCzcxn4tfu+3DS/E8xvTFsvJY3u2/ZeutmjTKuOBb4sG06Cs3dO8m8vHgUNmL/sEt+CP74/jyHBAS5SLbHM7ch61U0FvYqEfAzS9FQNjpodbhR/EcmWSfVpjolSv/IqKwZSGg== Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=nvidia.com; Received: from CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) by SA3PR12MB7880.namprd12.prod.outlook.com (2603:10b6:806:305::18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.8230.22; Wed, 11 Dec 2024 18:01:11 +0000 Received: from CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732]) by CH3PR12MB8659.namprd12.prod.outlook.com ([fe80::6eb6:7d37:7b4b:1732%5]) with mapi id 15.20.8251.008; Wed, 11 Dec 2024 18:01:10 +0000 Date: Wed, 11 Dec 2024 14:01:09 -0400 From: Jason Gunthorpe To: Nicolin Chen Cc: eric.auger@redhat.com, ddutile@redhat.com, Shameer Kolothum , qemu-arm@nongnu.org, qemu-devel@nongnu.org, peter.maydell@linaro.org, linuxarm@huawei.com, wangzhou1@hisilicon.com, jiangkunkun@huawei.com, jonathan.cameron@huawei.com, zhangfei.gao@linaro.org Subject: Re: [RFC PATCH 5/5] hw/arm/virt-acpi-build: Add IORT RMR regions to handle MSI nested binding Message-ID: <20241211180109.GO2347147@nvidia.com> References: <20241108125242.60136-1-shameerali.kolothum.thodi@huawei.com> <20241108125242.60136-6-shameerali.kolothum.thodi@huawei.com> <20241211004821.GM2347147@nvidia.com> <20241211131112.GN2347147@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MN0PR02CA0028.namprd02.prod.outlook.com (2603:10b6:208:530::22) To CH3PR12MB8659.namprd12.prod.outlook.com (2603:10b6:610:17c::13) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: CH3PR12MB8659:EE_|SA3PR12MB7880:EE_ X-MS-Office365-Filtering-Correlation-Id: 31672a01-1ff3-4853-b787-08dd1a0dcb4c X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|366016|376014|7416014; X-Microsoft-Antispam-Message-Info: =?us-ascii?Q?PNNh2DawRVmyYH59MyvMW+oleiaMlTU6gb4FTXmowr8PGCqMmgtp9YOGjWGN?= =?us-ascii?Q?bcLZ6ajT1U9/lTU6zZvjYeRXH4RC11n9ajPIidOEfvylMs9im9Q9j3LEnEza?= =?us-ascii?Q?MuOeafec3njf+OHnqsveTOpbIE6AKI9FFMFobXlukF42V0e7X1+ZNyYZLNh8?= =?us-ascii?Q?JTFUOgn4XMfQXDsek/q1DJTu4sARnok6+IIdcWnuMCbl/scQvMLihDgl9etn?= =?us-ascii?Q?vdbsT10xEicQPFEKaFGENb8OQQQpGGCwuCTqFKIvz2HDRaFyw0M07Fo7bROY?= =?us-ascii?Q?wLeisLi+snVy0SoSh52EL41zDeGXC81iEU31t36dOZSbd2Vy+wo6FCNNoDEO?= =?us-ascii?Q?0P2GkWwiMUjfSC3fXLHfOYztalHplWh8eHTSfon6aqir5HPX/0AyelVMYtK6?= =?us-ascii?Q?as4vfXGNiBTReyPMwClNam1YEh9kZRapIX5smSCBo59UhR5gKxDgO/UA1ABC?= =?us-ascii?Q?egxe+N8gF9A15PTajOwHRsLnMh0bHRWNubORutxyJQ3+A3qySRnTFFjgHy1a?= =?us-ascii?Q?E+ffw1CY3WYfIGptiHsTaUd1Updvd6pkY/YR1FMG426mccS0K0DRbihJQvPD?= =?us-ascii?Q?hWBLvIRsRG3dcfgDU0L32WM1yPbuLsnWhxeza01DNALZrmqkdgjXwWNIEqU+?= =?us-ascii?Q?QO9mB2Vu5ztE/22zHtLJxu0iWicaKMzuM5ug4DgJbDnm5eZiskZ5sBWdP6so?= =?us-ascii?Q?ghgHYgXJxxg/1VpQtO5etieo/k/ihWC5tqMz+gSoX9S4CnzPavynOJdi4bDj?= =?us-ascii?Q?b4lxyoy18dhDthrwgVScAw5BycV1mFValuIUDWGxvJ6wqSKI2f3qtB+mSEuA?= =?us-ascii?Q?oFpbwG8Wak+mPqMoCQqI64iS+MVA4sZ4Mdg1bVkqsstFSXCkK08fKGU1WVHn?= =?us-ascii?Q?rnvolqiLbLLT2BS6D6hwJI8mo1io7Oo22RlNKUx6zV11LhmNOnJmBjmDrMP4?= =?us-ascii?Q?IYt+ir8T5KJ9xtB6Gzc3VCkMvKnyxHE92HNq1FQASfa2ctbozYMt0YY8aaV9?= =?us-ascii?Q?YBs6pj5jjcOW/bKNfDQniREIulePFJ1rwhTpnyP9ebslO5rTcMPxD3TCBsM/?= =?us-ascii?Q?GwZlBCWcgl7Qjs/Viz+UO7sp9LDBMRxFDX60EGfb/wg/oEgUshd4r8qlz+0C?= =?us-ascii?Q?82pxxdrU3cfmBL4nVmv8aXMBxWJ8baRwORPM1SNNUakCYPovwKfEqH4IVofv?= =?us-ascii?Q?vWMa3PmKB5qX+jLysGye9YFgaqBqx0L1fkBPwiv/9LCm4dnH6zo/+F+kdC7o?= =?us-ascii?Q?Vd5REdGS+phnrhiG0zHoJQl6+RVl+svKW1xUSL0uniYvLZfjWARpINcKZi+P?= =?us-ascii?Q?vbDxHxzqAHsVfmsqcCcNkdGE/oZSYYlEOPrjpH7c8dOfDg=3D=3D?= X-Forefront-Antispam-Report: CIP:255.255.255.255; CTRY:; LANG:en; SCL:1; SRV:; IPV:NLI; SFV:NSPM; H:CH3PR12MB8659.namprd12.prod.outlook.com; PTR:; CAT:NONE; SFS:(13230040)(1800799024)(366016)(376014)(7416014); DIR:OUT; SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?THsZ0VFmvlyuI9rxBVeI9bwW6Wxbubsv4JmQ10WCAoytzMZtmbcPEFsHt3jB?= =?us-ascii?Q?aLkhqeFPBekFmt5dBpHblUxRh754O1EskgByN6c5P49eHo3YFwAhsS7RQkO6?= =?us-ascii?Q?S8/DcB0skp/9qcj3mCrJysSsaJeZdonN2Kp8KuGF7zPnnD2EFVWVq7mEmR0P?= =?us-ascii?Q?TghODID6eWAJIkOcJq/E3nwN9AzVgPQ/VG6hCWnFL7MEtCfqpwiGUHyFC4EE?= =?us-ascii?Q?qU5kE238aAmLC/6BKeA1LX7CaPHt9HTQWJN/nmqKRCCcH1PctSeySX82PEGY?= =?us-ascii?Q?O3gFhER4YX+QpZiMUSW/oW4t1tR3pTX6gwEskqbSCnbQvG9tRhDR5HSjnPH1?= =?us-ascii?Q?leJrkxYHTdrlMLoxtbWrPAVCMrNRxS/zJUqVMqI9fbJuavpSCqD+xNQOOlEL?= =?us-ascii?Q?JNihTEAUKDtREy1aauHa2kxZJ0x6fhKnO74zmRtJ0W4JlRKyDK/rpGCpoifp?= =?us-ascii?Q?wYEXoSXN9jy+OBhuOdhS1mGsnhtvHnCOhJkCodN2d3galdS8cr/GcBLVn9Ti?= =?us-ascii?Q?BNPwN+3/j5uQfxZObWB02R/VtIJKm36GqdFnEh18i8jzJl0/nNVIz76imear?= =?us-ascii?Q?UMmaqHdGm5E+iC9RdivisKq2MhoOx8CDkMJkZsxThHs64Axm+X99klxznnCY?= =?us-ascii?Q?24czV4BUjOAX1PTmzeuKiNIPglc6F5iSNj6UhaZXAB+nqup4k7fxi0HOfmnS?= =?us-ascii?Q?lcVK/F2ryjz8w93XOlNRqXfoKige5zd+uGcnaQ7rB4p4YJGFRGTUzfGq6aMT?= =?us-ascii?Q?S1zizypv5SegsFD3kToxKHFz5mtf8RHfojQlc9wLc0YU0E3LswEB8XOEJrqo?= =?us-ascii?Q?AjFbHDGbjH+bd2CBzunsdIgTlGgOYk5VzZ61T3D7Hgkwrc2S72qpze6HzE/X?= =?us-ascii?Q?AC0Fmx2ycKlZEIvKL9CYPpM3txl1c5kNROCm7QcYI1YrdcTtFxT6pmQY0ZdX?= =?us-ascii?Q?EuMG6yK9LJ0AVliF2R3Kx3B4Nb2RjIRrpcdOb7OJHcB0jofm9EBUBkWy32Fj?= =?us-ascii?Q?rnzsDSuA9FOaXIsBWfqaYAYuP1bnc47Hgh4VvymDwPPgyAadiNg2/Hkj6i3r?= =?us-ascii?Q?SKWXcM4Yq5qfgKOddbLu8DgKa6rL0SAxtOeejDueRPCElyhOGKp1xtsOw8wM?= =?us-ascii?Q?qb4Ppk/JbhVljpNx91UkkvR0sKZNGDQz/h6/Xvna+eaD/dAQ1LpkPlAS30Dp?= =?us-ascii?Q?9XwTxmNPlv9UBA5AG9h0vSPXfpftXZ2MCjlORLm9OSWQ9RIOUd6bZgkCHyqB?= =?us-ascii?Q?Lqz23NnvHyJF8OzsltkbHHhwtt6k0VBsgp5WapW8k7M3tWNVaMR9pIeseRLi?= =?us-ascii?Q?koQXcy9PGwfn+3T1j5DR9HvnK36cX+mUO1KfXOSnrTCKytP1OlWu0ZRmJx2T?= =?us-ascii?Q?nLdlV+/u4L6P9vdCubOLgbDInlv5sqx+pcSJRkLLDvXa5wlERKNXh4I5PYpL?= =?us-ascii?Q?8yNqKKG7wP94DKt7KdFNzWu7uNTP7wsS0IehKjpoxbFD4st1PDkUbNzpybPt?= =?us-ascii?Q?D2w8JvTuUpVCPsrdTlgr+64WgspdMRnYoKB1ig5+C6lRYE7nS/gj8aWB3D7e?= =?us-ascii?Q?s1hFdeb6lcITfDv0yVcT7QT8bdBmzKGAVnLzBfQL?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 31672a01-1ff3-4853-b787-08dd1a0dcb4c X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB8659.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Dec 2024 18:01:10.5683 (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: n+vuqK+nSH3cfOJnQfofQuS343q7er5oPfThp5wImfgifVXYiAg7xw5rosmGjza0 X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA3PR12MB7880 Received-SPF: softfail client-ip=2a01:111:f403:2009::624; envelope-from=jgg@nvidia.com; helo=NAM10-BN7-obe.outbound.protection.outlook.com X-Spam_score_int: -25 X-Spam_score: -2.6 X-Spam_bar: -- X-Spam_report: (-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.472, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-arm@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Sender: qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org X-TUID: 6B4WjaSFYckm On Wed, Dec 11, 2024 at 09:20:20AM -0800, Nicolin Chen wrote: > On Wed, Dec 11, 2024 at 09:11:12AM -0400, Jason Gunthorpe wrote: > > On Tue, Dec 10, 2024 at 05:28:17PM -0800, Nicolin Chen wrote: > > > > I would ideally turn it around and provide that range information to > > > > the kernel and totally ignore the SW_MSI reserved region once > > > > userspace provides it. > > > > > > Hmm.. that sounds like a uAPI for vITS range..but yes.. > > > > It controls the window that the kernel uses to dynamically map the ITS > > pages. > > Can we use SET_OPTION for vITS mapping (non-RMR solution) too? There are two parts to the vITS flow: 1) mapping the phsical ITS page - I expect this to go through IOMMUFD_CMD_IOAS_MAP_FILE 2) Conveying the MSI addr per-irq - this doesn't feel like set_option is quite the right fit since it is an array of msis > > > > So, VMM can GET_OPTION(SW_MSI) for msi_base to extract the > > > info from kernel. Likely need a second call for its length? > > > Since IOMMU_OPTION only supports one val64 input or output. > > > > No, just forget about the kernel's SW_MSI region. The VMM uses this > > API and overrides it and iommufd completely ignores SW_MSI. > > > > There is nothing special about the range hard coded into the smmu > > driver. > > OK. We will have SET_OPTION(IOMMU_OPTION_SW_MSI_START) and > SET_OPTION(IOMMU_OPTION_SW_MSI_LAST). Maybe length, but yes > I think we will need some validation to the range too, although > iommufd doesn't have the information about the underlying ITS > driver: what if user space sets range to a page size, while the > ITS driver requires multiple pages? Ideally the kernel would detect and fail IRQ setup in these cases. I suggest enforcing a minimal range of something XXM big at least, then it won't happen. Jason