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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?sx/7Q+O8BK+Q74CSls3VNRNNN8j2EUnHupvrLi80DuvoYz+D6pAAWjBYlEXv?= =?us-ascii?Q?j18+570U6MB/mFfSAt6M6EAD4VbBwX64KLG/Z40I1T5GN3/9E/i0aMZ9/Aq1?= =?us-ascii?Q?FmNp0GSIGC2WNb0HlY/aaVzhVtg3humt546EFW22T6hVucSb5uy7Fv3jNHYa?= =?us-ascii?Q?23OFNFAo/1CzV5GvAKxTT+YKy7aUxVP/0OnMz1IMF1kNLGIFYbvkFzlFfbfG?= =?us-ascii?Q?s3o90lRM0fyQRArbFsCOBsxHp3ihK0fhMYH3o+sJIyvezG9r31tt+fDPphN9?= =?us-ascii?Q?SK/At7Y0gb7fjWNgVbjj67bANYfe+FwXxRBRepMx6raveTUZ6UJxEW4qtb4Y?= =?us-ascii?Q?qzjwbluMXKhH7H3p5ozodPxoRPbtYMDE1Y55cI8nJS5DWZOH1BqA0AcoTfUa?= =?us-ascii?Q?azSORMwJoECEnOaMBnKNvGffajh9rCG8rDk2l0D79f0dWaFdsvZ2cNoULGvi?= =?us-ascii?Q?e+uquUwxm9+bqzo40yKZ1eIlEOhJdNJo6sfg5GCfvKm7SIIPoA2Y309wZzur?= =?us-ascii?Q?XO/VMioUI/CpIiBgWi+UaJj/yiAJDYz75j0Ap6QwgtwS7ZAVa9dlLwczEwdH?= =?us-ascii?Q?1LUW1sClcByDEDLYVKTLB3o3UnH6ZAjdkKjIoMV6qvtVktUfVJZHHESwWrlT?= =?us-ascii?Q?izL7jcAIWHeKF/MQYLmYsY2AA2px2+2+dRBpGB5AReDlQJxbjNH2REiLgYRD?= =?us-ascii?Q?iL0d8JETM7SZUWOvSLCezWeG6WWrj+yUs1s8U7LoyMewa4btu+9AxLnAP4VU?= =?us-ascii?Q?vndMRZKGJfIQGYuE1O063AOssd/6syNSX2K19iXHB/UZ6e+rnp4jkfX2DL35?= =?us-ascii?Q?whj4UgqRuqHTTKsnpwKCP6H5uP4Jyry8zUZR3zCJkgfZu67886xzkIY/6D7O?= =?us-ascii?Q?tr+ul/Qi7hGEH0ON1R+08u1cR2sd12tTnXvvuNZivrTuJ8/EyY2eHHpklxQf?= =?us-ascii?Q?C6Lpw/ugShvHWQ20skI+ZDGY/BnNSU2zRtP3G6Kkk9R3PHpRb7GQr4H7awBP?= =?us-ascii?Q?VVPMpekTE9m8Hxe2282LrV0mOxqqUkNAW3zAofH5ryeh7LR8M8yYyDafVcG3?= =?us-ascii?Q?rhsCucb4K1j91qwBzfAy7Bei8KS5+DLqTkF3mUm8JMlgX5uRC3wbp++GqItS?= =?us-ascii?Q?1zCnflunvdq7gtUTDiPEvFJWf1TVXGJiV7KQW/FWknc7HXuYa/aVQ6wBG/Kv?= =?us-ascii?Q?tsBkzAZBuRUWJ1BtX9I+0ncZ4iTGeA+wWG1j+nGOANXVZLGTUrcUit0eZDsP?= =?us-ascii?Q?wG/xWJtIAy+aSxAh0XGep1q/FG0720ruzELyI+W0OgZw30/3quZvTKR8Uzzc?= =?us-ascii?Q?esevzSbLZ9MQb5mUJgwCbLBW0bOCBYpOoOV15vxHvfuC/LLW4StDAreSDm9T?= =?us-ascii?Q?RiYUrWp7zuA4s52HR3s6hVfm1+byKqJqkXyQX7TctkdDnpXIcDG1hGUXor/N?= =?us-ascii?Q?XFAZSPkjVZ4/MzfDSYTHpYqGl442GT4OkTDUMd3QXLlNvURDFltBH8lEiR8V?= =?us-ascii?Q?BffIdQloIo5cf23aDFQP7kFaHoLtZCuEGK7PTVsncDeEt6sKyeskvKlnIUfl?= =?us-ascii?Q?Efy3ygHSQd2Vxhy7RJY=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: a248f923-7cc7-4198-1338-08ddf9d15c61 X-MS-Exchange-CrossTenant-AuthSource: PH7PR12MB5757.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Sep 2025 12:12:55.1488 (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: ZDqCYtRxv+zsXpWh6Es3dZx4NcKAOSKot4zqBOc3ko7sB8xSod1ul6/9ijxXjGY5 X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN7PR12MB7787 On Mon, Sep 22, 2025 at 06:59:10AM +0000, Kasireddy, Vivek wrote: > > You can't translate a dma_addr_t to anything in the Xe PF driver > > anyhow, once it goes through the IOMMU the necessary information is lost. > Well, I already tested this path (via IOMMU, with your earlier vfio-pci + > dmabuf patch that used dma_map_resource() and also with Leon's latest > version) and found that I could still do the translation in the Xe PF driver > after first calling iommu_iova_to_phys(). I would NAK any driver doing something so hacky. You are approaching this completely wrong to abuse things like this. > that there are no memory copies and the CPU is not involved. And, I don't see > any other way to do this because I don't believe the exporter can provide a > DMA address that the importer can use directly without any translation, which > seems unavoidable in this case. This is sadly how dmabuf is designed, please talk to Christain to figure out how to exchage the right kind of address. > use-case. And, I sincerely hope that it will work, otherwise I don't see > any viable path forward for what I am trying to do other than using this > quirk and translation. You will not get a quirk. > PCIe fabric). Isn't that one of the main ideas behind using quirks -- to > address hardware limitations? This is not a hardware limitation. You are using DMABUF wrong, writing hacks into the PF driver and then trying to make up a fake ACS quirk :( Jason