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charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-AuthSource: IA1PR11MB6097.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-Network-Message-Id: 462b3929-a1ee-4c8a-88d2-08daeeca3001 X-MS-Exchange-CrossTenant-originalarrivaltime: 05 Jan 2023 03:08:58.2089 (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: S8U5F2GMzOpRGijpPOVxQb/he2deIBSa5hGywUmUNkdNufpkenO+I/kl1p+MD0UZ/GMJqqwjDCetjNhTE958vA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ1PR11MB6275 X-OriginatorOrg: intel.com X-Rspamd-Queue-Id: 8B72C80009 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: 5nq6t6nkn5bjpf4hr35r7j7rnmy9uf9f X-HE-Tag: 1672888144-860651 X-HE-Meta: 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 9kucIxqy I8TK14gDi/xqCVPdfBAutrqa6ZnGIKSR6jeeCA/EjXOgdhji9NgyAydllC38NgIJ3nKN4RjKGcR3Y+zo= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi, Alistair, > Alistair Popple writes: > Lorenzo Stoakes writes: > > My concern is exposing something highly delicate _which accesses > > remote mas a public API with implicit assumptions whose one and only > > (core kernel) user treats with enormous caution. Even if this iommu > > code were to use it correctly, we'd end up with an interface which coul= d be > subject to real risks which other drivers may misuse. >=20 > Ok, although I think making this an iommu specific wrapper taking a PASID > rather than mm_struct would make the API more specific and less likely to= be > misused as the mm_count/users lifetime issues could be dealt with inside = the > core IOMMU code. The iommu specific wrapper still needs to call access_remote_vm() which is in generic mm. We cannot avoid to export access_remote_vm(), right? Are you saying the iommu specific wrapper doesn't need to the mm code? =20 Thanks. -Fenghua