Hi,
On Thu, Sep 28, 2017 at 09:03:57PM +0300, Volodymyr Babchuk wrote:
From: Volodymyr Babchuk vlad.babchuk@gmail.com
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.
I'm afraid that I don't follow the arguments for virtualized OP-TEE usage.
In a virtualised environment, TEE access *must* be mediated via the hypervisor, which can virtualise the interface, pin pages, etc.
Could you elaborate on how you expect TEE access to work in a virtualised environment?
Thanks, Mark.
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 getter functions
drivers/tee/optee/Makefile | 1 + drivers/tee/optee/call.c | 131 +++++++++++++++++++++- drivers/tee/optee/core.c | 160 +++++++++++++++++++++------ drivers/tee/optee/optee_msg.h | 38 ++++++- drivers/tee/optee/optee_private.h | 26 ++++- drivers/tee/optee/optee_smc.h | 7 ++ drivers/tee/optee/rpc.c | 72 ++++++++++-- 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 | 226 +++++++++++++++++++++++++++++++------- drivers/tee/tee_shm_pool.c | 165 +++++++++++++++++----------- include/linux/tee_drv.h | 184 ++++++++++++++++++++++++++++++- include/uapi/linux/tee.h | 30 +++++ 15 files changed, 1058 insertions(+), 221 deletions(-) create mode 100644 drivers/tee/optee/shm_pool.c create mode 100644 drivers/tee/optee/shm_pool.h
-- 2.7.4
linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel