RE: [PATCH v6 0/9] Replay Protected Memory Block (RPMB) subsystem

Winkler, Tomas
2016-09-20T11:59:08Z

>
> On Mon, Sep 19, 2016 at 12:17:48PM +0000, Winkler, Tomas wrote:
> > \
> > > Subject: [PATCH v6 0/9] Replay Protected Memory Block (RPMB)
> > > subsystem
> > >
> > >
> > > Few storage technologies such is EMMC, UFS, and NVMe support RPMB
> > > hardware partition with common protocol and frame layout.
> > > The RPMB partition cannot be accessed via standard block layer, but
> > > by a set of specific commands: WRITE, READ, GET_WRITE_COUNTER, and
> > > PROGRAM_KEY.
> > > Such a partition provides authenticated and replay protected access,
> > > hence suitable as a secure storage.
> > >
> > > The RPMB layer aims to provide in-kernel API for Trusted Execution
> > > Environment (TEE) devices that are capable to securely compute block
> > > frame signature. In case a TEE device wish to store a replay
> > > protected data, it creates an RPMB frame with requested data and
> > > computes HMAC of the frame, then it requests the storage device via
> RPMB layer to store the data.
> > >
> > > The layer provides two APIs, for rpmb_req_cmd() for issuing one of
> > > RPMB specific commands and rpmb_seq_cmd() for issuing of raw RPMB
> > > protocol frames, which is close to the functionality provided by
> > > emmc multi ioctl interface.
> > >
> > > A TEE driver can claim the RPMB interface, for example, via
> > > class_interface_register ().
> > >
> > > A storage device registers its RPMB hardware (eMMC) partition or
> > > RPMB W- LUN (UFS) with the RPMB layer providing an implementation
> > > for
> > > rpmb_seq_cmd() handler. The interface enables sending sequence of
> > > RPMB standard frames.
> > >
> > > A parallel user space API is provided via /dev/rpmbX character
> > > device with two IOCTL commands.
> > > Simplified one, RPMB_IOC_REQ_CMD, were read result cycles is
> > > performed by the framework on behalf the user and second,
> > > RPMB_IOC_SEQ_CMD where the whole RPMB sequence, including
> > > RESULT_READ is supplied by the caller.
> > > The latter is intended for easier adjusting of the applications that
> > > use MMC_IOC_MULTI_CMD ioctl, such as
> > > https://android.googlesource.com/trusty/app/storage/
> > >
> > > There is a also sample tool under tools/rpmb/ directory that
> > > exercises these interfaces and a simulation device that implements the
> device part.
> > >
> > > The code is also available from:
> > >
> > > https://github.com/tomasbw/linux-mei.git rpmb
> > >
> >
> > Greg, can you please check if this series has addressed all your comments.
> > Are there are any more items that preventing it from merging?
>
> Ugh, my queue is huge right now, give me a week or so to dig out of it and
> review this...
>
> Oh wait, you have almost no reviews from anyone else! Why is it up to me to
> do all of this work? :)

There were reviews I've addressed those as well, this is already 6th version of this series.

> Please get acks from others, at the very least, get it reviewed by other Intel
> kernel developers that we know and trust. I'm amazed you haven't already
> done that!

Adrian Hunter who is relevant from Intel is on the list. Also I've addressed his comments in v5. Adding Alan as he expressed some interest this code lately.
The code was of course reviewed and tested internally.
But this is indeed a good place to ask you the guys that addressed me privately or on the mailing list for additional review and yours X-by?

Thanks
Tomas

> thanks,
>
> greg k-h