Re: [RFC 15/18] vfio/iommufd: Implement iommufd backend

Alex Williamson
2022-04-22T22:42:27Z

On Fri, 22 Apr 2022 11:58:15 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> I don't see IOMMU_IOAS_IOVA_RANGES called at all, that seems like a
> problem..

Not as much as you might think. Note that you also won't find QEMU
testing VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE in the QEMU vfio-pci
driver either. The vfio-nvme driver does because it has control of the
address space it chooses to use, but for vfio-pci the address space is
dictated by the VM and there's not a lot of difference between knowing
in advance that a mapping conflicts with a reserved range or just
trying add the mapping and taking appropriate action if it fails.
Thanks,

Alex