RE: Plan for /dev/ioasid RFC v2

[Tian, Kevin]

> From: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Sent: Tuesday, June 29, 2021 7:09 AM
> 
> > > Ideally vfio would also at least be able to register a type1 IOMMU
> > > backend through the existing uapi, backed by this iommu code, ie. we'd
> > > create a new "iommufd" (but without the user visible fd),
> >
> > It would be amazing to be able to achieve this, at least for me there
> > are too many details be able to tell what that would look like
> > exactly. I suggested once that putting the container ioctl interface
> > in the drivers/iommu code may allow for this without too much trouble..
> 
> If we can't achieve this, then type1 legacy code is going to need to
> live through an extended deprecation period.  I'm hoping that between
> type1 and a native interface we'll have two paths into iommufd to vet
> the design.  Thanks,
> 

I prefer to keeping type1 legacy code for some time. After the new
device-centric flow works, we can then study how to make type1
as a shim layer atop.

Thanks
Kevin