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Tsirkin" , Nicolin Chen , Niklas Schnelle , Shameerali Kolothum Thodi , Yi Liu , Keqian Zhu Subject: Re: [PATCH RFC v2 02/13] iommufd: Overview documentation Message-ID: References: <0-v2-f9436d0bde78+4bb-iommufd_jgg@nvidia.com> <2-v2-f9436d0bde78+4bb-iommufd_jgg@nvidia.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MN2PR16CA0041.namprd16.prod.outlook.com (2603:10b6:208:234::10) To MN2PR12MB4192.namprd12.prod.outlook.com (2603:10b6:208:1d5::15) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: MN2PR12MB4192:EE_|SJ0PR12MB6687:EE_ X-MS-Office365-Filtering-Correlation-Id: c0b325d2-0001-4a7e-9129-08da9294710e 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:MN2PR12MB4192.namprd12.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230016)(4636009)(136003)(39860400002)(346002)(366004)(396003)(376002)(38100700002)(316002)(6916009)(54906003)(186003)(5660300002)(8676002)(2906002)(66556008)(66476007)(8936002)(66946007)(4326008)(2616005)(41300700001)(7416002)(6486002)(478600001)(83380400001)(6506007)(6512007)(26005)(36756003)(86362001);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?mOAcAtptPw2cQjOYzYhAwgmD1Dp2se1bAQygkt8GwKRBma1ixbkxOfnv6MKc?= =?us-ascii?Q?PBVcebYjnNcWZt6S+OOIIaCXUqoNqIup9+6YMWYHvlx+tWCIrXuMPcNDJEQi?= =?us-ascii?Q?XC3iSYp4iUgXefe6SgbkF02IvBEXqib+k7ORluv5cBZ516ccUZcFGnP0/0qr?= =?us-ascii?Q?HUEjRxpXTxJgpql9JJGHUKMD9Y+BGjxm83AenuUdY25v6/t/hVnYUO7FsZTs?= =?us-ascii?Q?4uqQWIDESraS13zAk8dyvgsbUzq/Xm+P6iIYiY0Xr+KIs4VAyfUMK1S/BW9I?= =?us-ascii?Q?UbmB0M0+6lsNWhD7vzDkwC8vlfbMb0+snJ0GHgHekw2NJlylZvfH5sMpqzcI?= =?us-ascii?Q?ThC9RQt3V+sd1doXCpJAsgZRnW3YodMoY3INCQe5YK3H6ip+6bGkWfnOpbIP?= =?us-ascii?Q?NNdqQuiiNfjEh4qLIdd3Bwalml/TrCYBvlBTWgJ27w2XX1/dSKrRkpZM5VKm?= =?us-ascii?Q?bP9ksOROEmzC1h5R7yNTSQudGNLFSIj7NokZr+YdYXw2b7dyI5BUy1Zb+NdE?= =?us-ascii?Q?z7L0MX7pv+BEZYKDS/62uguUfAA/sNe0qoTrr/zSkgAXkCEkUqSltxi48FHI?= =?us-ascii?Q?Sz9ODAjkmbyMfbxhR7TRkOBLeCoI1SIXpOLUIxQQh7RVsTdPllWYCljL6qse?= =?us-ascii?Q?BpI5gLDhjmtSE+gbwPsEMFrl/HEbYnVlhb6bjV68O2BGi15Qi3k+GTwob4Lr?= =?us-ascii?Q?XFawqPEfzL3GSKpLlLvaKGw4BufHONkYr/aj6pqYfZGbPJZMuroAhJY3HJYG?= =?us-ascii?Q?Wa6UNabPU2m2dG8Rz4L72EH2DoWnKiGZWd4QDtXvaIquFhdNIRiCUHbGXHZA?= =?us-ascii?Q?KqZIVFP037NY1FMqRAhSLmNmwcKvnlds4lv+dDlFzkRaS3OVU7PS60NKkR7/?= =?us-ascii?Q?KjXiKPXfUZ+hYb/+mFUOfS7Uw7LIBfKeuGGKEczLZWbsQPFHIvRJzwCu2Fo6?= =?us-ascii?Q?e+zqMZ+8QibV3IxFdzTIm/25OHdDifx4BQ5ZrfR3gpB8LdX8mpQxvzAW3k0+?= =?us-ascii?Q?EWyhbTj4UpLyFp+EBethtO9JAk/UfuBsXkJfLcs2piqcmZcFKxwteLQeEsB9?= =?us-ascii?Q?SXdWEw6NOMWUWRJuGe9gCclNrFn6Fac5SMvfZPPSG2sFQDKRMlkCxQsFKl3G?= =?us-ascii?Q?70AfrOFileSVcq6ktcJjQ0fgakox+Cyl+al74dnsX4+gzKapzLeP+geQhfX8?= =?us-ascii?Q?Kr13yB+x+6PoCbDiVyyiD4kc0iC75H8Rfl4rnJrnjy+mHNyJ7DeMa0fv+A9n?= =?us-ascii?Q?lIfrPIw2+nWU0MN5sGLHshE6jrzrHIDkZ/FwREvVtbxBaXq6PbtVOet+db5p?= =?us-ascii?Q?/A4hTsSR0EAfajvYbdQxmRJNEHCU5yZ5Oe6TrjIT+20sLWP/bCXJH+YAOL8Q?= =?us-ascii?Q?AUzXZqK3npltohg4kYWVIgMc+AczGGv9invqB8G5iHQvSHmx9bBh63dDiVd1?= =?us-ascii?Q?5eKNdOURewIPmDCbP3qeheNd425ve2ExgEqo6grC+4n95S1lQa+RqdRttvXJ?= =?us-ascii?Q?IdNqHCEraFx/uxgFSN5sJ1hjRc4nqAZOqVdKThJx/bGGT5UVtJtwAXHRq9mb?= =?us-ascii?Q?pmO4/iLfdSXoueYV7+8B1IZOhyRpzmI2U8g1R8sr?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: c0b325d2-0001-4a7e-9129-08da9294710e X-MS-Exchange-CrossTenant-AuthSource: MN2PR12MB4192.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Sep 2022 18:52:27.7972 (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: qcxZvHx/+SAuoEMdVwgwm4gpGvtNRsigY3OXv/ScSP4+JQK2HW3A1DLqIpMq0F8Z X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR12MB6687 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, Sep 07, 2022 at 11:39:51AM +1000, David Gibson wrote: > > +expected to deprecate any proprietary IOMMU logic, if existing (e.g. > > I don't thing "propietary" is an accurate description. Maybe > "existing" or "bespoke? How about "internal" These drivers are eventually expected to deprecate any internal IOMMU logic, if existing (e.g. vfio_iommu_type1.c). > > +All user-visible objects are destroyed via the IOMMU_DESTROY uAPI. > > + > > +Linkage between user-visible objects and external kernel datastructures are > > +reflected by dotted line arrows below, with numbers referring to certain > > I'm a little bit confused by the reference to "dotted line arrows": I > only see one arrow style in the diagram. I think this means all the "dashed lines with arrows" How about "by the directed lines below" > > +The iopt_pages is the center of the storage and motion of PFNs. Each iopt_pages > > +represents a logical linear array of full PFNs. PFNs are stored in a tiered > > +scheme: > > + > > + 1) iopt_pages::pinned_pfns xarray > > + 2) An iommu_domain > > + 3) The origin of the PFNs, i.e. the userspace pointer > > I can't follow what this "tiered scheme" is describing. Hum, I'm not sure how to address this. Is this better? 1) PFNs that have been "software accessed" stored in theiopt_pages::pinned_pfns xarray 2) PFNs stored inside the IOPTEs accessed through an iommu_domain 3) The origin of the PFNs, i.e. the userspace VA in a mm_struct Thanks, Jason