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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3C31DC5DF97 for ; Wed, 26 Aug 2026 16:33:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:In-Reply-To:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=qttZIt5CWPaJclv1YOt+6JgS8g3DeY1iutoFd6UWRfw=; b=NTE5ijOB5h/X6T 1vgH4iVthxDD+5ECCJuQ7JkW7+stTijWN8oSfDQlL3NLI7xMclpIE+qiliy5EcxeiM00HU9VqTqli PftbcxKdZO47CgqMTxNO2iGR/J6eMvZRJP4pS2/i+yJJ1dyOoyeY377nxBTniIGLQmHbx3IH/zmI1 SxOIZnVnASzaHq+JhV9qE3Cp1v5cgAV3Wl276hefUJBNSz5fLDLvifLfxwyoqpc94jl6aXonCz8od lcDBlG9bomjsi7Fr0nyzgjkRWedzPZ3cLN2AUr7jPMgMKIhJX8lXe+s0t7OI3Gl+P44woNZheUZJ/ X+kl92SV/Fu9s3rF/gwQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzGYS-00000002ktA-2xRA; Wed, 26 Aug 2026 16:32:48 +0000 Received: from mail-northcentralusazlp170130007.outbound.protection.outlook.com ([2a01:111:f403:c105::7] helo=CH4PR04CU002.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzGYQ-00000002ksg-0UlP for linux-riscv@lists.infradead.org; Wed, 26 Aug 2026 16:32:47 +0000 ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=JSNT1aS4bbUlTN7iTbNfW2JqUnEA5KinjcMF8BRY5JJzUbV0Io1+3QH0rMrfOIXAlxFt6I0LWjBWcWbDbGKvVTVHXN6nhPobCMGdemQYVsZ0/KFXHqzX6816j71HPbSPJ0OMB44Uer0lxuClgR52E03gPrEsz0sdejoUZyAxa9oVtIT43EWeCOrWbl27ORgFZfzccmq0drujv6CwNTGc3ZnPhRRisWMDkNJr71ON96GjNQF8Op7Ohxf+N/wnnAsa37jd/2TUmAtms2U5NwVPDbquQ9R5Bgi9pIejlmHfee7kCaFMKG9RPDNV39qs0jVX3Z4tFyoU6ofITsZ2bB3LxQ== 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=Q92kkrfCDBg+yUK3ar/4Q14YOu1rmNrZWmVKqODgM+c=; b=ADGHOtGIsO7N4VZjb+yfxw1OTe88S3ZSbJDgiTao2pswghifCUzTn2YOfnaw8hq4m4IB3USnoZe0hQF0gNED3Kc6fzljIEc/WGdcSQW/h9E1kCWIZvwP6qRSJzMqCWGsJej684AlvxAla4BKtSL7cyfVGdW4cMmovbbGHxgZb2hoZLKHP5MggR/XhR1ZapMaVjhHR53nkg8q6lcm4LUNnHp24Crv8ifvuYkg79bRfsaKPOdw8o9dOnbyP0Vb8EDCYyHWoRunFMs7GkUEDUX68T6KbUZdipn5CwKKecESHV8EfWJio0wE9aCm4mzIKjrVRWA6Nrisj7JscNr3cG9CSw== 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=Q92kkrfCDBg+yUK3ar/4Q14YOu1rmNrZWmVKqODgM+c=; b=CsY5i2TfLPgvy42h8kwxER0YITYnanX8GB23m5sAVWTQFaUQl2TiytSB19sqaBth2W/fL6Z8aBl64uBbtmwk1B90nracsT5gVw8ue5DcrS8UxsheGr2I0mCFsA6kSJ6E0TRWc5bKESS9+TSSPaB9raBWvcD4g1RXOHrRmT9eb04eQPrg+TQqq8KPHMj5CaGtM797opKG8KGFsBmfgXx5nDv9cJsvEUFXqWtryujJ1XLpARMtcbuf8h9ydSyC6LeuA0KXtG5w2XT2bh9J5wEtKVQQePJ31zwmAFX/wJBYShu/gD1MbNgQEaxy9xfotZeeX7kpXlPo1/RN/uRrGJTMDg== 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 BN7PPF0D942FA9A.namprd12.prod.outlook.com (2603:10b6:40f:fc02::6c7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.360.7; Wed, 26 Aug 2026 16:32:36 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%4]) with mapi id 15.21.0360.006; Wed, 26 Aug 2026 16:32:35 +0000 Date: Wed, 26 Aug 2026 13:32:34 -0300 From: Jason Gunthorpe To: Andrew Jones Cc: linux-riscv@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, tomasz.jeznach@linux.dev, tjeznach@rivosinc.com, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, pjw@kernel.org, palmer@dabbelt.com, anup@brainfault.org, tglx@kernel.org, kevin.tian@intel.com, fangyu.yu@linux.alibaba.com Subject: Re: [PATCH v4 02/21] iommufd: Add iommufd_sw_map_msi() Message-ID: <20260826163234.GN3325090@nvidia.com> References: <20260824125204.GP244917@nvidia.com> <20260824170417.GR244917@nvidia.com> <3gdj54zcs5dncgom3zlntyredyuh2xe5ueg7nd4pdrcksmnwfl@k3fyky4h6556> <20260825140334.GA3325090@nvidia.com> <20260825165209.GB3325090@nvidia.com> <20260825175901.GE3325090@nvidia.com> Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BN9PR03CA0423.namprd03.prod.outlook.com (2603:10b6:408:113::8) To LV8PR12MB9620.namprd12.prod.outlook.com (2603:10b6:408:2a1::19) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LV8PR12MB9620:EE_|BN7PPF0D942FA9A:EE_ X-MS-Office365-Filtering-Correlation-Id: c34f0b8c-6bea-4488-5040-08df038fa26f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|1800799024|366016|7416014|376014|56012099006|10067099003|22082099003|18002099003|11063799006|4143699003; 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)(23010399003)(1800799024)(366016)(7416014)(376014)(56012099006)(10067099003)(22082099003)(18002099003)(11063799006)(4143699003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?9BUEj3+AQJUuaxgkVh4yn5cJiqVa54Jod7qMRcDdbYM3+p7qcTPsNVoaqZwi?= =?us-ascii?Q?lBt/xHOVDb2HQ1MRVGap/XznPPvMBaJGvbwVjABhniaQfFG4lkdIhbm41g+c?= =?us-ascii?Q?3xkfYQPSnBa2QrNA8o7T1xHNKbxuTZr37P3KvvICOgm6YmiiW3jQc+280E//?= =?us-ascii?Q?4O1RBVwaNDPfNJS2gTPt7zlvJ89diwP48cqMgFpRY8yKqoJYaPt0dRTUoI/v?= =?us-ascii?Q?BhKOjvS+y5kAixIrJIpKnVm/pW6/HWAleTZpovBAso4bTaTMS0aLIoRsgWmW?= =?us-ascii?Q?4m02IrBZD2DCCkXKucGxyNIKiEgogCzsxEgsSKqwloIUUTupb7fqdM7W25Mi?= =?us-ascii?Q?yWWyrB3hJ0hOPUBsaVK6FCQd9oJBHj8ZjcL4sKyfr0z0DxoIUua5LaJo9Crq?= =?us-ascii?Q?Ua84DoTEliBsPBZZCQNRrmT5AWTFcXwYs7oFRk7K/aej0/odZC+Uny07VFMg?= =?us-ascii?Q?3zRt8P6/AXwvQ+LNhgid6/ceU9fSIh6TSITdLrpWsZjj1J70SgwV23VWKvuI?= =?us-ascii?Q?udoytXMrAOPta7sTLgCxDnOeFSOFIsq+dqLQn6z9ifmtce43qNRmzcNO1FYn?= =?us-ascii?Q?qQKoR4qtU+3U0+14MoveICYn0RuIxzCS/0e4Imhd58xBGqxoTWp815ve+fu2?= =?us-ascii?Q?f6Hpe18y8Mm8d1W+43Nz238Ui6dfBAkarQc3KZiDvAQnhNQItOpISMRmyYSc?= =?us-ascii?Q?xLSRb+S/K2cE6T5JU3XOX6A4otKYPY045uxPsIUuPPTaQDOjDVHdyZvsfnDZ?= =?us-ascii?Q?L6OOL+LEXPDM3NGltuVPZhVdzWRnMQ+hkRo7Uz/rQd8kGzjUiLAVDQNevo5J?= =?us-ascii?Q?K8z7WJjreUYeB0loARuKMghX65FtDRPhThtJf2URWFMbQPz2jhOHKhLmWSWE?= =?us-ascii?Q?pYtMAYTpjoL+MyvogMgGJJ46t57+IMxx+YsJdLGv8GPV3UJlALXOeIIcNt1W?= =?us-ascii?Q?A3uJ1PMrp7O0Lyiy7dQCPIEI8Nu9PcHtDshvNE7FshSENS3aFhnM0iX9L98N?= =?us-ascii?Q?te06ZQU3vx6YSTakj542T2mWRby40+ChRjcyIWP2eWPBZNU6WLcmVWW4abnD?= =?us-ascii?Q?OQu7AoLb+/9TRC8xXZ9HBcbWj5XchZQmT5L3fzuMknP81dpTJ36t0Ljepya7?= =?us-ascii?Q?rUAQ6P06dIV4U1fKFaDhZ13MugdZudUG3i2fXHo236tMrN+HKsqsSIDJ/SGb?= =?us-ascii?Q?Y/BDFQg1jXX9H7Glhuru+6wex67ElyAyYfGMIHELcokCmI9Ylqxe4JfxCn0A?= =?us-ascii?Q?5g1r6Him5Nld1RIv20h+kLRP4GXx2BrFEFOZHRKcpR9L1EetI0TJ6fA1Lmtv?= =?us-ascii?Q?rOTVyfIMX0Chmfn5ls/qDMkiJMY/E2nviPijB/ykQrhcECHeRfAxGkIVU4CP?= =?us-ascii?Q?B494nVxDKaOuN/sEzc/YV5R3fF3OHRsG44A9ejuTjIWU1V8D6D5DFNlNQgoo?= =?us-ascii?Q?KLt4e12he+iq8RVUFOMm2K6da967FC2Dgw/xaKtXCc0pH8v1Uw2myevLgPa3?= =?us-ascii?Q?8jr7/EaofPa2NTwOo0bcPJsCkjG9RfkFAqoSUfKQqR720ZZ9h7nx/0TSbMbx?= =?us-ascii?Q?/4Mc35l5e0C7Y88Qd0p42lx4Q10hw3f7b2p6b+8A7g0p3lZ4M/Ome07VwbeH?= =?us-ascii?Q?qU4SiQDr+SPYs6huBG1+5EjuO5+nFKIFJ8p0h7hbUAs8ZPn3PY5PqmrrWBTA?= =?us-ascii?Q?ZZAnhZI296Vri0xioe/u0zJY3CDC7z4JD6JlQ6g2vmfNhGIk?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c34f0b8c-6bea-4488-5040-08df038fa26f X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Aug 2026 16:32:35.1770 (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: oa8E4iv6RtF8CZBG9OiZiAHfNlTsH+aP+RESeIGdNxi0A60u59VivW79OvdfOEp2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN7PPF0D942FA9A X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260826_093246_291957_303DEDA5 X-CRM114-Status: UNSURE ( 9.20 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Wed, Aug 26, 2026 at 10:23:20AM +0200, Andrew Jones wrote: > RISC-V uses the same basic model as x86 (an IOMMU-owned interrupt > remapping IRQ domain). x86 makes that domain per-IOMMU because its IRTE > resources belong to the IOMMU instance. RISC-V makes it per-device because > its callbacks operate on the device's attached IOMMU domain and preserve > that device's existing MSI parent. The IRQ callbacks provide the lifecycle > hooks, even though the mappings, MSI table, and device context all remain > IOMMU state. The irq domain isn't per device, it is per msi table, many devices can share the same table, and the VM should have a single shared table across all devices. That's the core uniquely RISCV wrinkle I think. IDK how Thomas would like to model this, but you will get a better result if it is very clearly explained and asked. I would like to keep the iommu out of it, so I prefer if IRQ code patches in its MSI table pointer broadly the same way AMD does. Though AMD doesn't have the restriction that remapping only works with a S2 domain :( Jason _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from SJ2PR03CU001.outbound.protection.outlook.com (mail-westusazon11012005.outbound.protection.outlook.com [52.101.43.5]) (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 CB73044C646 for ; Wed, 26 Aug 2026 16:32:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.43.5 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787761967; cv=fail; b=nBPbv9DlgHd+uz8Tjc7Vmbb+sx6R9JIa7ltJtzLmYdmdTPNY8rrt1ZCG8H9uPcfJWaYkKUukPHQFQBSI9ryZN6k8m1procnOWRUmd9F65Msun7jO41dYfSOfd4Ag6eMYAr8EMkEUGHRRSXTxCIdWNzb8D1rUXRwjve35+fy8s/M= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787761967; c=relaxed/simple; bh=Q92kkrfCDBg+yUK3ar/4Q14YOu1rmNrZWmVKqODgM+c=; h=Date:From:To:Cc:Subject:Message-ID:References:Content-Type: Content-Disposition:In-Reply-To:MIME-Version; b=H9TFRsdkeipqhA2s5aG7A70J7P1qOIST3RYk55F0DSUaeFueM9rDBRFah6g1zFuohcAkzL2ylc4eszExCYzguXVKV+6Awa1fRmksbsAPHI/1zvSM+zAB0sGpRmVWHMuIRlIvfgCUoPfWfC8t2CN/LGmedTtmOEDKt+yyliVHaQY= 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=CsY5i2Tf; arc=fail smtp.client-ip=52.101.43.5 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="CsY5i2Tf" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=JSNT1aS4bbUlTN7iTbNfW2JqUnEA5KinjcMF8BRY5JJzUbV0Io1+3QH0rMrfOIXAlxFt6I0LWjBWcWbDbGKvVTVHXN6nhPobCMGdemQYVsZ0/KFXHqzX6816j71HPbSPJ0OMB44Uer0lxuClgR52E03gPrEsz0sdejoUZyAxa9oVtIT43EWeCOrWbl27ORgFZfzccmq0drujv6CwNTGc3ZnPhRRisWMDkNJr71ON96GjNQF8Op7Ohxf+N/wnnAsa37jd/2TUmAtms2U5NwVPDbquQ9R5Bgi9pIejlmHfee7kCaFMKG9RPDNV39qs0jVX3Z4tFyoU6ofITsZ2bB3LxQ== 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=Q92kkrfCDBg+yUK3ar/4Q14YOu1rmNrZWmVKqODgM+c=; b=ADGHOtGIsO7N4VZjb+yfxw1OTe88S3ZSbJDgiTao2pswghifCUzTn2YOfnaw8hq4m4IB3USnoZe0hQF0gNED3Kc6fzljIEc/WGdcSQW/h9E1kCWIZvwP6qRSJzMqCWGsJej684AlvxAla4BKtSL7cyfVGdW4cMmovbbGHxgZb2hoZLKHP5MggR/XhR1ZapMaVjhHR53nkg8q6lcm4LUNnHp24Crv8ifvuYkg79bRfsaKPOdw8o9dOnbyP0Vb8EDCYyHWoRunFMs7GkUEDUX68T6KbUZdipn5CwKKecESHV8EfWJio0wE9aCm4mzIKjrVRWA6Nrisj7JscNr3cG9CSw== 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=Q92kkrfCDBg+yUK3ar/4Q14YOu1rmNrZWmVKqODgM+c=; b=CsY5i2TfLPgvy42h8kwxER0YITYnanX8GB23m5sAVWTQFaUQl2TiytSB19sqaBth2W/fL6Z8aBl64uBbtmwk1B90nracsT5gVw8ue5DcrS8UxsheGr2I0mCFsA6kSJ6E0TRWc5bKESS9+TSSPaB9raBWvcD4g1RXOHrRmT9eb04eQPrg+TQqq8KPHMj5CaGtM797opKG8KGFsBmfgXx5nDv9cJsvEUFXqWtryujJ1XLpARMtcbuf8h9ydSyC6LeuA0KXtG5w2XT2bh9J5wEtKVQQePJ31zwmAFX/wJBYShu/gD1MbNgQEaxy9xfotZeeX7kpXlPo1/RN/uRrGJTMDg== 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 BN7PPF0D942FA9A.namprd12.prod.outlook.com (2603:10b6:40f:fc02::6c7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.360.7; Wed, 26 Aug 2026 16:32:36 +0000 Received: from LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528]) by LV8PR12MB9620.namprd12.prod.outlook.com ([fe80::299d:f5e0:3550:1528%4]) with mapi id 15.21.0360.006; Wed, 26 Aug 2026 16:32:35 +0000 Date: Wed, 26 Aug 2026 13:32:34 -0300 From: Jason Gunthorpe To: Andrew Jones Cc: linux-riscv@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org, tomasz.jeznach@linux.dev, tjeznach@rivosinc.com, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, pjw@kernel.org, palmer@dabbelt.com, anup@brainfault.org, tglx@kernel.org, kevin.tian@intel.com, fangyu.yu@linux.alibaba.com Subject: Re: [PATCH v4 02/21] iommufd: Add iommufd_sw_map_msi() Message-ID: <20260826163234.GN3325090@nvidia.com> References: <20260824125204.GP244917@nvidia.com> <20260824170417.GR244917@nvidia.com> <3gdj54zcs5dncgom3zlntyredyuh2xe5ueg7nd4pdrcksmnwfl@k3fyky4h6556> <20260825140334.GA3325090@nvidia.com> <20260825165209.GB3325090@nvidia.com> <20260825175901.GE3325090@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: BN9PR03CA0423.namprd03.prod.outlook.com (2603:10b6:408:113::8) 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_|BN7PPF0D942FA9A:EE_ X-MS-Office365-Filtering-Correlation-Id: c34f0b8c-6bea-4488-5040-08df038fa26f X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|23010399003|1800799024|366016|7416014|376014|56012099006|10067099003|22082099003|18002099003|11063799006|4143699003; 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)(23010399003)(1800799024)(366016)(7416014)(376014)(56012099006)(10067099003)(22082099003)(18002099003)(11063799006)(4143699003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?9BUEj3+AQJUuaxgkVh4yn5cJiqVa54Jod7qMRcDdbYM3+p7qcTPsNVoaqZwi?= =?us-ascii?Q?lBt/xHOVDb2HQ1MRVGap/XznPPvMBaJGvbwVjABhniaQfFG4lkdIhbm41g+c?= =?us-ascii?Q?3xkfYQPSnBa2QrNA8o7T1xHNKbxuTZr37P3KvvICOgm6YmiiW3jQc+280E//?= =?us-ascii?Q?4O1RBVwaNDPfNJS2gTPt7zlvJ89diwP48cqMgFpRY8yKqoJYaPt0dRTUoI/v?= =?us-ascii?Q?BhKOjvS+y5kAixIrJIpKnVm/pW6/HWAleTZpovBAso4bTaTMS0aLIoRsgWmW?= =?us-ascii?Q?4m02IrBZD2DCCkXKucGxyNIKiEgogCzsxEgsSKqwloIUUTupb7fqdM7W25Mi?= =?us-ascii?Q?yWWyrB3hJ0hOPUBsaVK6FCQd9oJBHj8ZjcL4sKyfr0z0DxoIUua5LaJo9Crq?= =?us-ascii?Q?Ua84DoTEliBsPBZZCQNRrmT5AWTFcXwYs7oFRk7K/aej0/odZC+Uny07VFMg?= =?us-ascii?Q?3zRt8P6/AXwvQ+LNhgid6/ceU9fSIh6TSITdLrpWsZjj1J70SgwV23VWKvuI?= =?us-ascii?Q?udoytXMrAOPta7sTLgCxDnOeFSOFIsq+dqLQn6z9ifmtce43qNRmzcNO1FYn?= =?us-ascii?Q?qQKoR4qtU+3U0+14MoveICYn0RuIxzCS/0e4Imhd58xBGqxoTWp815ve+fu2?= =?us-ascii?Q?f6Hpe18y8Mm8d1W+43Nz238Ui6dfBAkarQc3KZiDvAQnhNQItOpISMRmyYSc?= =?us-ascii?Q?xLSRb+S/K2cE6T5JU3XOX6A4otKYPY045uxPsIUuPPTaQDOjDVHdyZvsfnDZ?= =?us-ascii?Q?L6OOL+LEXPDM3NGltuVPZhVdzWRnMQ+hkRo7Uz/rQd8kGzjUiLAVDQNevo5J?= =?us-ascii?Q?K8z7WJjreUYeB0loARuKMghX65FtDRPhThtJf2URWFMbQPz2jhOHKhLmWSWE?= =?us-ascii?Q?pYtMAYTpjoL+MyvogMgGJJ46t57+IMxx+YsJdLGv8GPV3UJlALXOeIIcNt1W?= =?us-ascii?Q?A3uJ1PMrp7O0Lyiy7dQCPIEI8Nu9PcHtDshvNE7FshSENS3aFhnM0iX9L98N?= =?us-ascii?Q?te06ZQU3vx6YSTakj542T2mWRby40+ChRjcyIWP2eWPBZNU6WLcmVWW4abnD?= =?us-ascii?Q?OQu7AoLb+/9TRC8xXZ9HBcbWj5XchZQmT5L3fzuMknP81dpTJ36t0Ljepya7?= =?us-ascii?Q?rUAQ6P06dIV4U1fKFaDhZ13MugdZudUG3i2fXHo236tMrN+HKsqsSIDJ/SGb?= =?us-ascii?Q?Y/BDFQg1jXX9H7Glhuru+6wex67ElyAyYfGMIHELcokCmI9Ylqxe4JfxCn0A?= =?us-ascii?Q?5g1r6Him5Nld1RIv20h+kLRP4GXx2BrFEFOZHRKcpR9L1EetI0TJ6fA1Lmtv?= =?us-ascii?Q?rOTVyfIMX0Chmfn5ls/qDMkiJMY/E2nviPijB/ykQrhcECHeRfAxGkIVU4CP?= =?us-ascii?Q?B494nVxDKaOuN/sEzc/YV5R3fF3OHRsG44A9ejuTjIWU1V8D6D5DFNlNQgoo?= =?us-ascii?Q?KLt4e12he+iq8RVUFOMm2K6da967FC2Dgw/xaKtXCc0pH8v1Uw2myevLgPa3?= =?us-ascii?Q?8jr7/EaofPa2NTwOo0bcPJsCkjG9RfkFAqoSUfKQqR720ZZ9h7nx/0TSbMbx?= =?us-ascii?Q?/4Mc35l5e0C7Y88Qd0p42lx4Q10hw3f7b2p6b+8A7g0p3lZ4M/Ome07VwbeH?= =?us-ascii?Q?qU4SiQDr+SPYs6huBG1+5EjuO5+nFKIFJ8p0h7hbUAs8ZPn3PY5PqmrrWBTA?= =?us-ascii?Q?ZZAnhZI296Vri0xioe/u0zJY3CDC7z4JD6JlQ6g2vmfNhGIk?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c34f0b8c-6bea-4488-5040-08df038fa26f X-MS-Exchange-CrossTenant-AuthSource: LV8PR12MB9620.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 26 Aug 2026 16:32:35.1770 (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: oa8E4iv6RtF8CZBG9OiZiAHfNlTsH+aP+RESeIGdNxi0A60u59VivW79OvdfOEp2 X-MS-Exchange-Transport-CrossTenantHeadersStamped: BN7PPF0D942FA9A On Wed, Aug 26, 2026 at 10:23:20AM +0200, Andrew Jones wrote: > RISC-V uses the same basic model as x86 (an IOMMU-owned interrupt > remapping IRQ domain). x86 makes that domain per-IOMMU because its IRTE > resources belong to the IOMMU instance. RISC-V makes it per-device because > its callbacks operate on the device's attached IOMMU domain and preserve > that device's existing MSI parent. The IRQ callbacks provide the lifecycle > hooks, even though the mappings, MSI table, and device context all remain > IOMMU state. The irq domain isn't per device, it is per msi table, many devices can share the same table, and the VM should have a single shared table across all devices. That's the core uniquely RISCV wrinkle I think. IDK how Thomas would like to model this, but you will get a better result if it is very clearly explained and asked. I would like to keep the iommu out of it, so I prefer if IRQ code patches in its MSI table pointer broadly the same way AMD does. Though AMD doesn't have the restriction that remapping only works with a S2 domain :( Jason