Re: [PATCH v2 22/26] iommufd: Add hw_queue_init and split queue alloc paths

[Jason Gunthorpe]

On Thu, May 28, 2026 at 05:17:34AM +0000, Suravee Suthikulpanit wrote:
> Add iommufd_viommu_ops.hw_queue_init for vIOMMU backends whose
> hardware uses a guest physical queue base from hw_queue->base_addr
> instead of a host physical address.
> 
> Previously, HW queue alloc always went through
> iommufd_hw_queue_alloc_phys(), an iommufd_access, and
> hw_queue_init_phys(base_pa). AMD vIOMMU instead takes GPA from
> userspace in hw_queue->base_addr and programs hardware without host PA
> resolution. Splitting helpers and dispatching from the ioctl keeps
> one uAPI while making the contract explicit. Each vIOMMU driver should
> implement only one of hw_queue_init_phys or hw_queue_init.
> 
> Refactor iommufd_hw_queue_alloc_ioctl() so shared validation and
> viommu lookup stay in the ioctl, while setup is delegated to
> _iommufd_hw_queue_init_phys() or _iommufd_hw_queue_init().

This patch series is getting pretty big, getting the viommu working
alone is enough for one series, I would split getting the direct
assigned queues working to a following series

Jason