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Subject[PATCH v1 00/14] tee: optee: add dynamic shared memory support
Date
From: Volodymyr Babchuk <vlad.babchuk@gmail.com>

Changes from v1:

* Added support for 16K and 64K pages.
* Elaborated commit messages
* More minor changes are described in corresponding patches.

While this patches are necessary for use OP-TEE in virualized environment,
they are not sufficient. Stuart Yoder was right, when proposed to make
static SHM optional. But that would be a breaking change, because this
will render unusable older client libraries and supplicants.

Also, as Mark Rutland pointed, OP-TEE virtualization will need support
from hypervisor side.

Anyways, those patches allowed me to call OP-TEE from XEN's Dom0 without
remapping static SHM region into Dom0 userspace.

Also, this patches allow me to share quite big buffers (I tried to
use three 2M buffers at a time). This is imposible with static SHM,
because static SHM on most platforms is only 2M.

Thanks to Yury Norov <ynorov@caviumnetworks.com> and
Mark Rutland <mark.rutland@arm.com> for reviewing this patch series.

---
v1 cover letter:
This patch series enables dynamic shared memory support in the TEE
subsystem as a whole and in OP-TEE in particular.

Global Platform TEE specification [1] allows client applications
to register part of own memory as a shared buffer between
application and TEE. This allows fast zero-copy communication between
TEE and REE. But current implementation of TEE in Linux does not support
this feature.

Also, current implementation of OP-TEE transport uses fixed size
pre-shared buffer for all communications with OP-TEE OS. This is okay
in the most use cases. But this prevents use of OP-TEE in virtualized
environments, because:
a) We can't share the same buffer between different virtual machines
b) Physically contiguous memory as seen by VM can be non-contiguous
in reality (and as seen by OP-TEE OS) due to second stage of
MMU translation.
c) Size of this pre-shared buffer is limited.

So, first part of this patch series adds generic register/unregister
interface to tee subsystem. Next patches add necessary features
into OP-TEE driver, so it can use not only static pre-shared buffer,
but whole RAM to communicate with OP-TEE OS.

[1] https://www.globalplatform.org/specificationsdevice.asp

Jens Wiklander (2):
tee: flexible shared memory pool creation
tee: add register user memory

Volodymyr Babchuk (12):
tee: shm: add accessors for buffer size and page offset
tee: shm: add page accessor functions
tee: optee: Update protocol definitions
tee: optee: add page list manipulation functions
tee: optee: add shared buffer registration functions
tee: optee: add registered shared parameters handling
tee: optee: add registered buffers handling into RPC calls
tee: optee: store OP-TEE capabilities in private data
tee: optee: add optee-specific shared pool implementation
tee: optee: enable dynamic SHM support
tee: use reference counting for tee_context
tee: shm: inline tee_shm_get_id()

drivers/tee/optee/Makefile | 1 +
drivers/tee/optee/call.c | 179 +++++++++++++++++++++++++++++-
drivers/tee/optee/core.c | 152 +++++++++++++++++++------
drivers/tee/optee/optee_msg.h | 38 ++++++-
drivers/tee/optee/optee_private.h | 27 ++++-
drivers/tee/optee/optee_smc.h | 7 ++
drivers/tee/optee/rpc.c | 77 +++++++++++--
drivers/tee/optee/shm_pool.c | 75 +++++++++++++
drivers/tee/optee/shm_pool.h | 23 ++++
drivers/tee/tee_core.c | 81 ++++++++++++--
drivers/tee/tee_private.h | 60 +---------
drivers/tee/tee_shm.c | 227 +++++++++++++++++++++++++++++++-------
drivers/tee/tee_shm_pool.c | 165 ++++++++++++++++-----------
include/linux/tee_drv.h | 183 +++++++++++++++++++++++++++++-
include/uapi/linux/tee.h | 30 +++++
15 files changed, 1104 insertions(+), 221 deletions(-)
create mode 100644 drivers/tee/optee/shm_pool.c
create mode 100644 drivers/tee/optee/shm_pool.h

--
2.7.4

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