On 6/14/2025 3:14 PM, Nicolin Chen wrote:
For vIOMMU passing through HW resources to user space (VMs), allowing a VM to control the passed through HW directly by accessing hardware registers, add an mmap infrastructure to map the physical MMIO pages to user space. Maintain a maple tree per ictx as a translation table managing mmappable regions, from an allocated for-user mmap offset to an iommufd_mmap struct, where it stores the real PFN range for an io_remap_pfn_range call. Keep track of the lifecycle of the mmappable region by taking refcount of its owner, so as to enforce user space to unmap the region first before it can destroy its owner object. To allow an IOMMU driver to add and delete mmappable regions onto/from the maple tree, add iommufd_viommu_alloc/destroy_mmap helpers. Reviewed-by: Kevin Tian<kevin.tian@xxxxxxxxx> Signed-off-by: Nicolin Chen<nicolinc@xxxxxxxxxx>
Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
