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From:   "Tian, Kevin" <kevin.tian@intel.com>
To:     Alex Williamson <alex.williamson@redhat.com>,
        Jason Gunthorpe <jgg@nvidia.com>
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Subject: RE: Plan for /dev/ioasid RFC v2
Thread-Topic: Plan for /dev/ioasid RFC v2
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Date:   Tue, 29 Jun 2021 00:28:29 +0000
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> From: Alex Williamson <alex.williamson@redhat.com>
> Sent: Tuesday, June 29, 2021 7:09 AM
>=20
> > > 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..
>=20
> 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,
>=20

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