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 Buffer, and PPR Log Buffer
Introduce an allocator iommufd_hw_queue_alloc(). And add a pair of viommu ops for iommufd to forward user space ioctls to IOMMU drivers.
Given that the first user of this HW QUEUE (tegra241-cmdqv) will need to ensure the queue memory to be physically contiguous, add a flag property in iommufd_viommu_ops and IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA to allow driver to flag it so that the core will validate the physical pages of a given guest queue.
Reviewed-by: Lu Baolu baolu.lu@linux.intel.com Reviewed-by: Pranjal Shrivastava praan@google.com Reviewed-by: Vasant Hegde vasant.hegde@amd.com Signed-off-by: Nicolin Chen nicolinc@nvidia.com --- include/linux/iommufd.h | 47 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+)
diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index 266ac6805213..923c66ccc15a 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -38,6 +38,7 @@ 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 @@ -133,6 +134,24 @@ struct iommufd_vdevice { u64 id; /* per-vIOMMU virtual ID */ };
+struct iommufd_hw_queue { + struct iommufd_object obj; + struct iommufd_ctx *ictx; + struct iommufd_viommu *viommu; + u64 base_addr; /* in guest physical address space */ + size_t length; +}; + +enum iommufd_viommu_flags { + /* + * The HW does not go through an address translation table but reads the + * physical address space directly: iommufd core should pin the physical + * pages backing the queue memory that's allocated for the HW QUEUE, and + * ensure those physical pages are contiguous in the physical space. + */ + IOMMUFD_VIOMMU_FLAG_HW_QUEUE_READS_PA = 1 << 0, +}; + /** * struct iommufd_viommu_ops - vIOMMU specific operations * @destroy: Clean up all driver-specific parts of an iommufd_viommu. The memory @@ -158,8 +177,18 @@ struct iommufd_vdevice { * @vdevice_destroy: Clean up all driver-specific parts of an iommufd_vdevice. * The memory of the vDEVICE will be free-ed by iommufd core * after calling this op + * @hw_queue_alloc: Allocate a HW QUEUE object for a HW-accelerated queue given + * the @type (must be defined in include/uapi/linux/iommufd.h) + * for the @viommu. @index carries the logical HW QUEUE ID per + * @viommu in a guest VM, for a multi-queue model; @base_addr + * carries the guest physical base address of the queue memory; + * @length carries the size of the queue + * @hw_queue_destroy: Clean up all driver-specific parts of an iommufd_hw_queue. + * The memory of the HW QUEUE will be free-ed by iommufd core + * after calling this op */ struct iommufd_viommu_ops { + u32 flags; void (*destroy)(struct iommufd_viommu *viommu); struct iommu_domain *(*alloc_domain_nested)( struct iommufd_viommu *viommu, u32 flags, @@ -171,6 +200,10 @@ struct iommufd_viommu_ops { struct device *dev, u64 virt_id); void (*vdevice_destroy)(struct iommufd_vdevice *vdev); + struct iommufd_hw_queue *(*hw_queue_alloc)( + struct iommufd_ucmd *ucmd, struct iommufd_viommu *viommu, + unsigned int type, u32 index, u64 base_addr, size_t length); + void (*hw_queue_destroy)(struct iommufd_hw_queue *hw_queue); };
#if IS_ENABLED(CONFIG_IOMMUFD) @@ -312,4 +345,18 @@ static inline int iommufd_viommu_report_event(struct iommufd_viommu *viommu, } \ ret; \ }) + +#define iommufd_hw_queue_alloc(ucmd, viommu, drv_struct, member) \ + ({ \ + drv_struct *ret; \ + \ + static_assert(__same_type(struct iommufd_viommu, *viommu)); \ + ret = (drv_struct *)__iommufd_object_alloc_ucmd( \ + ucmd, ret, IOMMUFD_OBJ_HW_QUEUE, member.obj); \ + if (!IS_ERR(ret)) { \ + ret->member.viommu = viommu; \ + ret->member.ictx = viommu->ictx; \ + } \ + ret; \ + }) #endif