Re: [PATCH v2 02/19] iommufd/viommu: Add IOMMUFD_OBJ_VIOMMU and IOMMU_VIOMMU_ALLOC ioctl

On Thu, Sep 05, 2024 at 12:53:02PM -0300, Jason Gunthorpe wrote:

On Tue, Aug 27, 2024 at 09:59:39AM -0700, Nicolin Chen wrote:

quoted

+/**
+ * struct iommu_viommu_alloc - ioctl(IOMMU_VIOMMU_ALLOC)
+ * @size: sizeof(struct iommu_viommu_alloc)
+ * @flags: Must be 0
+ * @type: Type of the virtual IOMMU. Must be defined in enum iommu_viommu_type
+ * @dev_id: The device to allocate this virtual IOMMU for

@dev_id: The device's physical IOMMU will be used to back t he vIOMMU

quoted

+ * @hwpt_id: ID of a nesting parent HWPT to associate to

A nesting parent HWPT that will provide translation for an vIOMMU DMA

quoted

+ * @out_viommu_id: Output virtual IOMMU ID for the allocated object
+ *
+ * Allocate a virtual IOMMU object that holds a (shared) nesting parent HWPT

Allocate a virtual IOMMU object that represents the underlying
physical IOMMU's virtualization support. The vIOMMU object is a
security isolated slice of the physical IOMMU HW that is unique to a
specific VM. Operations global to the IOMMU are connected to the
vIOMMU, such as:
  - Security namespace for guest owned ID, eg guest controlled cache tags
  - Virtualization of various platforms IDs like RIDs and others
  - direct assigned invalidation queues
  - direct assigned interrupts
  - non-affiliated event reporting
  - Delivery of paravirtualized invalidation

Ack.

Looks like you prefer using "vIOMMU" v.s. "VIOMMU"? I would go
through all the patches (QEMU including) to keep that aligned.

Thanks
Nicolin