Re: [RFC PATCH 06/21] vfio/pci: Accept live update preservation request for VFIO cdev

[Jason Gunthorpe]

On Mon, Oct 27, 2025 at 01:44:30PM -0700, Jacob Pan wrote:
> I have a separate question regarding noiommu devices. I’m currently
> working on adding noiommu mode support for VFIO cdev under iommufd.

Oh how is that going? I was just thinking about that again..

After writing the generic pt self test it occured to me we now have
enough infrastructure for iommufd to internally create its own
iommu_domain with a AMDv1 page table for the noiommu devices. It would
then be so easy to feed that through the existing machinery and have
all the pinning/etc work.

Then only an ioctl to read back the physical addresses from this
special domain would be needed

It actually sort of feels pretty easy..

Jason