Re: [PATCH 11/12] habanalabs/gaudi2: add tpm attestation info uapi

[Oded Gabbay]

On Tue, Jun 28, 2022 at 9:36 AM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, Jun 27, 2022 at 11:26:19PM +0300, Oded Gabbay wrote:
> > From: Dani Liberman <dliberman@xxxxxxxxx>
> >
> > User will provide a nonce via the ioctl, and will retrieve
> > attestation data of the boot from the tpm, generated using given
> > nonce.
>
> Why not use the normal TPM api instead of a new/custom one?  Or is this
> not a "normal" TPM device?  If not, you should say what it really is.
>
> thanks,
>
> greg k-h

Honestly, I'm not that knowledgeable about it. It is hidden behind our
firmware code. We just provide a communication method between the
userspace and the firmware, as the userspace can't interact directly
with the f/w. i.e. The driver is a transparent tunnel, it doesn't
interact with registers of the TPM device itself. The "real" driver is
in our firmware.

So basically we just got definitions from the f/w how to fetch the
data from them and how to expose it to the user and that's it.

What to do in this case ? Is this considered a "real" TPM ? I imagine
I won't be able to connect to a standard tpm driver in the kernel as
the h/w is not exposed to me.

Oded