From ed42eee797ff3dc889ade63c1dd7c4f430699e23 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Wed, 9 Jul 2025 22:59:04 -0700 Subject: iommufd/viommu: Add driver-defined vDEVICE support NVIDIA VCMDQ driver will have a driver-defined vDEVICE structure and do some HW configurations with that. To allow IOMMU drivers to define their own vDEVICE structures, move the struct iommufd_vdevice to the public header and provide a pair of viommu ops, similar to get_viommu_size and viommu_init. Doing this, however, creates a new window between the vDEVICE allocation and its driver-level initialization, during which an abort could happen but it can't invoke a driver destroy function from the struct viommu_ops since the driver structure isn't initialized yet. vIOMMU object doesn't have this problem, since its destroy op is set via the viommu_ops by the driver viommu_init function. Thus, vDEVICE should do something similar: add a destroy function pointer inside the struct iommufd_vdevice instead of the struct iommufd_viommu_ops. Note that there is unlikely a use case for a type dependent vDEVICE, so a static vdevice_size is probably enough for the near term instead of a get_vdevice_size function op. Link: https://patch.msgid.link/r/1e751c01da7863c669314d8e27fdb89eabcf5605.1752126748.git.nicolinc@nvidia.com Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian Reviewed-by: Pranjal Shrivastava Reviewed-by: Lu Baolu Reviewed-by: Vasant Hegde Signed-off-by: Nicolin Chen Signed-off-by: Jason Gunthorpe --- include/linux/iommufd.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) (limited to 'include/linux') diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 2d1bf2f97ee3..bdd10a85eeef 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -104,6 +104,21 @@ struct iommufd_viommu { enum iommu_viommu_type type; }; +struct iommufd_vdevice { + struct iommufd_object obj; + struct iommufd_viommu *viommu; + struct device *dev; + + /* + * Virtual device ID per vIOMMU, e.g. vSID of ARM SMMUv3, vDeviceID of + * AMD IOMMU, and vRID of Intel VT-d + */ + u64 virt_id; + + /* Clean up all driver-specific parts of an iommufd_vdevice */ + void (*destroy)(struct iommufd_vdevice *vdev); +}; + /** * struct iommufd_viommu_ops - vIOMMU specific operations * @destroy: Clean up all driver-specific parts of an iommufd_viommu. The memory @@ -120,6 +135,14 @@ struct iommufd_viommu { * array->entry_num to report the number of handled requests. * The data structure of the array entry must be defined in * include/uapi/linux/iommufd.h + * @vdevice_size: Size of the driver-defined vDEVICE structure per this vIOMMU + * @vdevice_init: Initialize the driver-level structure of a vDEVICE object, or + * related HW procedure. @vdev is already initialized by iommufd + * core: vdev->dev and vdev->viommu pointers; vdev->id carries a + * per-vIOMMU virtual ID (refer to struct iommu_vdevice_alloc in + * include/uapi/linux/iommufd.h) + * If driver has a deinit function to revert what vdevice_init op + * does, it should set it to the @vdev->destroy function pointer */ struct iommufd_viommu_ops { void (*destroy)(struct iommufd_viommu *viommu); @@ -128,6 +151,8 @@ struct iommufd_viommu_ops { const struct iommu_user_data *user_data); int (*cache_invalidate)(struct iommufd_viommu *viommu, struct iommu_user_data_array *array); + const size_t vdevice_size; + int (*vdevice_init)(struct iommufd_vdevice *vdev); }; #if IS_ENABLED(CONFIG_IOMMUFD) @@ -224,4 +249,10 @@ static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu, BUILD_BUG_ON_ZERO(offsetof(drv_struct, member)) + \ BUILD_BUG_ON_ZERO(!__same_type(struct iommufd_viommu, \ ((drv_struct *)NULL)->member))) + +#define VDEVICE_STRUCT_SIZE(drv_struct, member) \ + (sizeof(drv_struct) + \ + BUILD_BUG_ON_ZERO(offsetof(drv_struct, member)) + \ + BUILD_BUG_ON_ZERO(!__same_type(struct iommufd_vdevice, \ + ((drv_struct *)NULL)->member))) #endif -- cgit v1.2.3