Add IOMMUFD_OBJ_HW_QUEUE with an iommufd_hw_queue structure, representing a HW-accelerated queue type of IOMMU's physical queue that can be passed through to a user space VM for direct hardware control, such as: - NVIDIA's Virtual Command Queue - AMD vIOMMU's Command Buffer, Event Log Buffers, and PPR Log Buffers
Add new viommu ops for iommufd to communicate with IOMMU drivers to fetch supported HW queue structure size and to forward user space ioctls to the IOMMU drivers for initialization/destroy.
As the existing HWs, NVIDIA's VCMDQs access the guest memory via physical addresses, while AMD's Buffers access the guest memory via guest physical addresses (i.e. iova of the nesting parent HWPT). Separate two mutually exclusive hw_queue_init and hw_queue_init_phys ops to indicate whether a vIOMMU HW accesses the guest queue in the guest physical space (via iova) or the host physical space (via pa).
In a latter case, the iommufd core will validate the physical pages of a given guest queue, to ensure the underlying physical pages are contiguous and pinned.
Since this is introduced with NVIDIA's VCMDQs, add hw_queue_init_phys for now, and leave some notes for hw_queue_init in the near future (for AMD).
Either NVIDIA's or AMD's HW is a multi-queue model: NVIDIA's will be only one type in enum iommu_hw_queue_type, while AMD's will be three different types (two of which will have multi queues). Compared to letting the core manage multiple queues with three types per vIOMMU object, it'd be easier for the driver to manage that by having three different driver-structure arrays per vIOMMU object. Thus, pass in the index to the init op.
Reviewed-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Pranjal Shrivastava praan@google.com Reviewed-by: Vasant Hegde vasant.hegde@amd.com Reviewed-by: Kevin Tian kevin.tian@intel.com Reviewed-by: Jason Gunthorpe jgg@nvidia.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- include/linux/iommufd.h | 42 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/iommufd.h | 9 ++++++++ 2 files changed, 51 insertions(+)
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 3709b264af28..808536ed97e0 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -37,6 +37,7 @@ enum iommufd_object_type { IOMMUFD_OBJ_VIOMMU, IOMMUFD_OBJ_VDEVICE, IOMMUFD_OBJ_VEVENTQ, + IOMMUFD_OBJ_HW_QUEUE, #ifdef CONFIG_IOMMUFD_TEST IOMMUFD_OBJ_SELFTEST, #endif @@ -119,6 +120,19 @@ struct iommufd_vdevice { void (*destroy)(struct iommufd_vdevice *vdev); };
+struct iommufd_hw_queue { + struct iommufd_object obj; + struct iommufd_viommu *viommu; + + u64 base_addr; /* in guest physical address space */ + size_t length; + + enum iommu_hw_queue_type type; + + /* Clean up all driver-specific parts of an iommufd_hw_queue */ + void (*destroy)(struct iommufd_hw_queue *hw_queue); +}; + /** * struct iommufd_viommu_ops - vIOMMU specific operations * @destroy: Clean up all driver-specific parts of an iommufd_viommu. The memory @@ -143,6 +157,22 @@ struct iommufd_vdevice { * 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 + * @get_hw_queue_size: Get the size of a driver-defined HW queue structure for a + * given @viommu corresponding to @queue_type. Driver should + * return 0 if HW queue aren't supported accordingly. It is + * required for driver to use the HW_QUEUE_STRUCT_SIZE macro + * to sanitize the driver-level HW queue structure related + * to the core one + * @hw_queue_init_phys: Initialize the driver-level structure of a HW queue that + * is initialized with its core-level structure that holds + * all the info about a guest queue memory. + * Driver providing this op indicates that HW accesses the + * guest queue memory via physical addresses. + * @index carries the logical HW QUEUE ID per vIOMMU in a + * guest VM, for a multi-queue model. @base_addr_pa carries + * the physical location of the guest queue + * If driver has a deinit function to revert what this op + * does, it should set it to the @hw_queue->destroy pointer */ struct iommufd_viommu_ops { void (*destroy)(struct iommufd_viommu *viommu); @@ -153,6 +183,11 @@ struct iommufd_viommu_ops { struct iommu_user_data_array *array); const size_t vdevice_size; int (*vdevice_init)(struct iommufd_vdevice *vdev); + size_t (*get_hw_queue_size)(struct iommufd_viommu *viommu, + enum iommu_hw_queue_type queue_type); + /* AMD's HW will add hw_queue_init simply using @hw_queue->base_addr */ + int (*hw_queue_init_phys)(struct iommufd_hw_queue *hw_queue, u32 index, + phys_addr_t base_addr_pa); };
#if IS_ENABLED(CONFIG_IOMMUFD) @@ -255,4 +290,11 @@ 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_vdevice, \ ((drv_struct *)NULL)->member))) + +#define HW_QUEUE_STRUCT_SIZE(drv_struct, member) \ + (sizeof(drv_struct) + \ + BUILD_BUG_ON_ZERO(offsetof(drv_struct, member)) + \ + BUILD_BUG_ON_ZERO(!__same_type(struct iommufd_hw_queue, \ + ((drv_struct *)NULL)->member))) + #endif diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 272da7324a2b..971aa19c0ba1 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -1147,4 +1147,13 @@ struct iommu_veventq_alloc { __u32 __reserved; }; #define IOMMU_VEVENTQ_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_VEVENTQ_ALLOC) + +/** + * enum iommu_hw_queue_type - HW Queue Type + * @IOMMU_HW_QUEUE_TYPE_DEFAULT: Reserved for future use + */ +enum iommu_hw_queue_type { + IOMMU_HW_QUEUE_TYPE_DEFAULT = 0, +}; + #endif