RE: [PATCH v6 08/10] iommufd: Associate fault object with iommufd_hw_pgtable

[Tian, Kevin]

> From: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
> Sent: Monday, May 27, 2024 12:05 PM
> 
> When allocating a user iommufd_hw_pagetable, the user space is allowed to
> associate a fault object with the hw_pagetable by specifying the fault
> object ID in the page table allocation data and setting the
> IOMMU_HWPT_FAULT_ID_VALID flag bit.
> 
> On a successful return of hwpt allocation, the user can retrieve and
> respond to page faults by reading and writing the file interface of the
> fault object.
> 
> Once a fault object has been associated with a hwpt, the hwpt is
> iopf-capable, indicated by hwpt->fault is non NULL. Attaching,
> detaching, or replacing an iopf-capable hwpt to an RID or PASID will
> differ from those that are not iopf-capable.
> 
> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>