Regards
Manuel
On Tue, May 07, 2024 at 11:16:16AM +0200, Jens Wiklander wrote:
> Hi,
>
> This patch set introduces a new RPMB subsystem, based on patches
from [1],
> [2], and [3]. The RPMB subsystem aims at providing access to RPMB
> partitions to other kernel drivers, in particular the OP-TEE
driver. A new
> user space ABI isn't needed, we can instead continue using the
already
> present ABI when writing the RPMB key during production.
>
> I've added and removed things to keep only what is needed by the
OP-TEE
> driver. Since the posting of [3], there has been major changes in
the MMC
> subsystem so "mmc: block: register RPMB partition with the RPMB
subsystem"
> is in practice completely rewritten.
>
> With this OP-TEE can access RPMB during early boot instead of
having to
> wait for user space to become available as in the current design
[4].
> This will benefit the efi variables [5] since we wont rely on
userspace as
> well as some TPM issues [6] that were solved.
>
> The OP-TEE driver finds the correct RPMB device to interact with
by
> iterating over available devices until one is found with a
programmed
> authentication matching the one OP-TEE is using. This enables
coexisting
> users of other RPMBs since the owner can be determined by who
knows the
> authentication key.
>
> The corresponding secure world OP-TEE patches are available at
[7].
>
> I've put myself as a maintainer for the RPMB subsystem as I have
an
> interest in the OP-TEE driver to keep this in good shape.
However, if you'd
> rather see someone else taking the maintainership that's fine
too. I'll
> help keep the subsystem updated regardless.
>
> [1]
https://lore.kernel.org/lkml/20230722014037.42647-1-shyamsaini@xxxxxxxxxxxxxxxxxxx/
> [2]
https://lore.kernel.org/lkml/20220405093759.1126835-2-alex.bennee@xxxxxxxxxx/
> [3]
https://lore.kernel.org/linux-mmc/1478548394-8184-2-git-send-email-tomas.winkler@xxxxxxxxx/
> [4]
https://optee.readthedocs.io/en/latest/architecture/secure_storage.html#rpmb-secure-storage
> [5]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c44b6be62e8dd4ee0a308c36a70620613e6fc55f
> [6]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7269cba53d906cf257c139d3b3a53ad272176bca
> [7] https://github.com/jenswi-linaro/optee_os/tree/rpmb_probe_v6
>
> Thanks,
> Jens
>
> Changes since v5:
> Manuel Traut reported and investigated an error on an i.MX8MM,
the root
> cause was identified as insufficient alignment on frames sent to
the RPMB
> device. Fixed in the OP-TEE driver as described below.
> * "rpmb: add Replay Protected Memory Block (RPMB) subsystem"
> - Adding a missing EXPORT_SYMBOL_GPL()
> * "optee: probe RPMB device using RPMB subsystem"
> - Replacing the old OPTEE_RPC_CMD_RPMB ABI with
OPTEE_RPC_CMD_RPMB_FRAMES
> to get rid of the small header struct rpmb_req (now removed)
causing
> the problem.
> - Matching changes on the secure side + support for
re-initializing
> RPMB in case a boot stage has used RPMB, the latter also
reported by
> Manuel Traut.
>
> Changes since v4:
> * "rpmb: add Replay Protected Memory Block (RPMB) subsystem"
> - Describing struct rpmb_descr as RPMB description instead of
descriptor
> * "mmc: block: register RPMB partition with the RPMB subsystem"
> - Addressing review comments
> - Adding more comments for struct rpmb_frame
> - Fixing assignment of reliable_wr_count and capacity in
mmc_blk_rpmb_add()
> * "optee: probe RPMB device using RPMB subsystem"
> - Updating struct rpmb_dev_info to match changes in "rpmb: add
Replay
> Protected Memory Block (RPMB) subsystem"
>
> Changes since v3:
> * Move struct rpmb_frame into the MMC driver since the format of
the RPMB
> frames depend on the implementation, one format for eMMC,
another for
> UFS, and so on
> * "rpmb: add Replay Protected Memory Block (RPMB) subsystem"
> - Adding Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> - Adding more description of the API functions
> - Removing the set_dev_info() op from struct rpmb_ops, the
needed information
> is supplied in the arguments to rpmb_dev_register() instead.
> - Getting rid of struct rpmb_ops since only the route_frames()
op was
> remaining, store that op directly in struct rpmb_dev
> - Changed rpmb_interface_register() and
rpmb_interface_unregister() to use
> notifier_block instead of implementing the same thing
ourselves
> * "mmc: block: register RPMB partition with the RPMB subsystem"
> - Moving the call to rpmb_dev_register() to be done at the end
of
> mmc_blk_probe() when the device is fully available
> * "optee: probe RPMB device using RPMB subsystem"
> - Use IS_REACHABLE(CONFIG_RPMB) to determine if the RPMB
subsystem is
> available
> - Translate TEE_ERROR_STORAGE_NOT_AVAILABLE if encountered in
get_devices()
> to recognize the error in optee_rpmb_scan()
> - Simplified optee_rpmb_scan() and optee_rpmb_intf_rdev()
>
> Changes since v2:
> * "rpmb: add Replay Protected Memory Block (RPMB) subsystem"
> - Fixing documentation issues
> - Adding a "depends on MMC" in the Kconfig
> - Removed the class-device and the embedded device, struct
rpmb_dev now
> relies on the parent device for reference counting as
requested
> - Removed the now unneeded rpmb_ops get_resources() and
put_resources()
> since references are already taken in
mmc_blk_alloc_rpmb_part() before
> rpmb_dev_register() is called
> - Added rpmb_interface_{,un}register() now that
> class_interface_{,un}register() can't be used ay longer
> * "mmc: block: register RPMB partition with the RPMB subsystem"
> - Adding the missing error cleanup in alloc_idata()
> - Taking the needed reference to md->disk in
mmc_blk_alloc_rpmb_part()
> instead of in mmc_rpmb_chrdev_open() and
rpmb_op_mmc_get_resources()
> * "optee: probe RPMB device using RPMB subsystem"
> - Registering to get a notification when an RPMB device comes
online
> - Probes for RPMB devices each time an RPMB device comes
online, until
> a usable device is found
> - When a usable RPMB device is found, call
> optee_enumerate_devices(PTA_CMD_GET_DEVICES_RPMB)
> - Pass type of rpmb in return value from
OPTEE_RPC_CMD_RPMB_PROBE_NEXT
>
> Changes since Shyam's RFC:
> * Removed the remaining leftover rpmb_cdev_*() function calls
> * Refactored the struct rpmb_ops with all the previous ops
replaced, in
> some sense closer to [3] with the route_frames() op
> * Added rpmb_route_frames()
> * Added struct rpmb_frame, enum rpmb_op_result, and enum
rpmb_type from [3]
> * Removed all functions not needed in the OP-TEE use case
> * Added "mmc: block: register RPMB partition with the RPMB
subsystem", based
> on the commit with the same name in [3]
> * Added "optee: probe RPMB device using RPMB subsystem" for
integration
> with OP-TEE
> * Moved the RPMB driver into drivers/misc/rpmb-core.c
> * Added my name to MODULE_AUTHOR() in rpmb-core.c
> * Added an rpmb_mutex to serialize access to the IDA
> * Removed the target parameter from all rpmb_*() functions since
it's
> currently unused
>
> Jens Wiklander (3):
> rpmb: add Replay Protected Memory Block (RPMB) subsystem
> mmc: block: register RPMB partition with the RPMB subsystem
> optee: probe RPMB device using RPMB subsystem
>
> MAINTAINERS | 7 +
> drivers/misc/Kconfig | 10 ++
> drivers/misc/Makefile | 1 +
> drivers/misc/rpmb-core.c | 233
+++++++++++++++++++++++++++++
> drivers/mmc/core/block.c | 241
+++++++++++++++++++++++++++++-
> drivers/tee/optee/core.c | 30 ++++
> drivers/tee/optee/device.c | 7 +
> drivers/tee/optee/ffa_abi.c | 8 +
> drivers/tee/optee/optee_private.h | 21 ++-
> drivers/tee/optee/optee_rpc_cmd.h | 35 +++++
> drivers/tee/optee/rpc.c | 166 ++++++++++++++++++++
> drivers/tee/optee/smc_abi.c | 7 +
> include/linux/rpmb.h | 136 +++++++++++++++++
> 13 files changed, 899 insertions(+), 3 deletions(-)
> create mode 100644 drivers/misc/rpmb-core.c
> create mode 100644 include/linux/rpmb.h
>
> --
> 2.34.1
>
