Re: [RFC PATCH 08/12] vfio/pci: Create host unaccessible dma-buf for private device

[Alexey Kardashevskiy]

On 15/1/25 00:35, Jason Gunthorpe wrote:
> On Tue, Jun 18, 2024 at 07:28:43AM +0800, Xu Yilun wrote:
>
> > > is needed so the secure world can prepare anything it needs prior to
> > > starting the VM.
> >
> > OK. From Dan's patchset there are some touch point for vendor tsm
> > drivers to do secure world preparation. e.g. pci_tsm_ops::probe().
> >
> > Maybe we could move to Dan's thread for discussion.
> >
> > https://lore.kernel.org/linux-coco/173343739517.1074769.13134786548545925484.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx/
>
> I think Dan's series is different, any uapi from that series should
> not be used in the VMM case. We need proper vfio APIs for the VMM to
> use. I would expect VFIO to be calling some of that infrastructure.

Something like this experiment?

https://github.com/aik/linux/commit/ce052512fb8784e19745d4cb222e23cabc57792e

Thanks,

> Really, I don't see a clear sense of how this will look yet. AMD
> provided some patches along these lines, I have not seem ARM and Intel
> proposals yet, not do I sense there is alignment.
>
> > > Setting up secure vIOMMU emulation, for instance. I
> >
> > I think this could be done at VM late bind time.
>
> The vIOMMU needs to be setup before the VM boots
>
> > > secure. This should all be pre-arranged as possible before starting
> >
> > But our current implementation is not to prepare as much as possible,
> > but only necessary, so most of the secure work for vPCI function is done
> > at late bind time.
>
> That's fine too, but both options need to be valid.
>
> Jason

--
Alexey