Re: [PATCH v6 2/2] fTPM: add documentation for ftpm driver

[Sasha Levin]

On Tue, Jun 25, 2019 at 12:59:02PM -0700, Randy Dunlap wrote:
> On 6/25/19 12:52 PM, Sasha Levin wrote:
> > This patch adds basic documentation to describe the new fTPM driver.
> >
> > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
> > ---
> >  Documentation/security/tpm/index.rst        |  1 +
> >  Documentation/security/tpm/tpm_ftpm_tee.rst | 31 +++++++++++++++++++++
> >  2 files changed, 32 insertions(+)
> >  create mode 100644 Documentation/security/tpm/tpm_ftpm_tee.rst
> >
> > diff --git a/Documentation/security/tpm/index.rst b/Documentation/security/tpm/index.rst
> > index af77a7bbb070..15783668644f 100644
> > --- a/Documentation/security/tpm/index.rst
> > +++ b/Documentation/security/tpm/index.rst
> > @@ -4,4 +4,5 @@ Trusted Platform Module documentation
> >
> >  .. toctree::
> >
> > +   tpm_ftpm_tee
> >     tpm_vtpm_proxy
> > diff --git a/Documentation/security/tpm/tpm_ftpm_tee.rst b/Documentation/security/tpm/tpm_ftpm_tee.rst
> > new file mode 100644
> > index 000000000000..29c2f8b5ed10
> > --- /dev/null
> > +++ b/Documentation/security/tpm/tpm_ftpm_tee.rst
> > @@ -0,0 +1,31 @@
> > +=============================================
> > +Firmware TPM Driver
> > +=============================================
> > +
> > +| Authors:
> > +| Thirupathaiah Annapureddy <thiruan@xxxxxxxxxxxxx>
> > +| Sasha Levin <sashal@xxxxxxxxxx>
> > +
> > +This document describes the firmware Trusted Platform Module (fTPM)
> > +device driver.
> > +
> > +Introduction
> > +============
> > +
> > +This driver is a shim for a firmware implemented in ARM's TrustZone
>
>                         for firmware
>
> > +environment. The driver allows programs to interact with the TPM in the same
> > +way the would interact with a hardware TPM.
>
>       they
>
> > +
> > +Design
> > +======
> > +
> > +The driver acts as a thin layer that passes commands to and from a TPM
> > +implemented in firmware. The driver itself doesn't contain much logic and is
> > +used more like a dumb pipe between firmware and kernel/userspace.
> > +
> > +The firmware itself is based on the following paper:
> > +https://www.microsoft.com/en-us/research/wp-content/uploads/2017/06/ftpm1.pdf
> > +
> > +When the driver is loaded it will expose ``/dev/tpmX`` character devices to
> > +userspace which will enable userspace to communicate with the firmware tpm
>
>                                                                          TPM
>
> > +through this device.
>
> Oh, that's the same comments that I made on 2019-06-18:
> https://marc.info/?l=linux-integrity&m=156087157019368&w=2

Appologies Randy, I've missed it. I'll send a new ver in a moment.
Thanks!

--
Thanks,
Sasha