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

On Thu, Sep 05, 2024 at 02:41:00PM -0300, Jason Gunthorpe wrote:

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+ * @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.

Also write something about the HWPT..

Assuming it's about sharing parent HWPT, ack.

Nicolin