RE: [PATCH v3 07/17] iommufd: Add IOMMU_RESV_IOVA_RANGES

[Tian, Kevin]

> From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> Sent: Monday, July 24, 2023 7:04 PM
> 
> This reports device's reserved IOVA regions to userspace. This is needed
> in the nested translation as userspace owns stage-1 HWPT, and userspace
> needs to exclude the reserved IOVA regions in the stage-1 HWPT hence
> exclude
> them in the device's DMA address space.
> 
> This can also be used to figure out allowed IOVAs of an IOAS.

We may need a special type to mark SW_MSI since it requires identity
mapping in stage-1 instead of being reserved.