Re: [RFC PATCH v2 14/22] iommufd: Add TIO calls

[Jason Gunthorpe <jgg@ziepe.ca>]

On Wed, Feb 26, 2025 at 11:12:32AM +1100, Alexey Kardashevskiy wrote:
> > I still have concern about the vdevice interface for bind. Bind put the
> > device to LOCKED state, so is more of a device configuration rather
> > than an iommu configuration. So seems more reasonable put the API in VFIO?
> 
> IOMMUFD means pretty much VFIO (in the same way "VFIO means KVM" as 95+% of
> VFIO users use it from KVM, although VFIO works fine without KVM) so not
> much difference where to put this API and can be done either way. VFIO is
> reasonable, the immediate problem is that IOMMUFD's vIOMMU knows the guest
> BDFn (well, for AMD) and VFIO PCI does not.

I would re-enforce what I said before, VFIO & iommufd alone should be
able to operate a TDISP device and get device encrpytion without
requiring KVM.

It makes sense that if the secure firmware object handles (like the
viommu, vdevice, vBDF) are accessed through iommufd then iommufd will
relay operations against those handles.

Jason