Hi, This patch set allocates the restricted DMA-bufs via the TEE subsystem. This a complete rewrite compared to the previous patch set [1], and other earlier proposals [2] and [3] with a separate restricted heap. The TEE subsystem handles the DMA-buf allocations since it is the TEE (OP-TEE, AMD-TEE, TS-TEE, or a future QTEE) which sets up the restrictions for the memory used for the DMA-bufs. I've added a new IOCTL, TEE_IOC_RSTMEM_ALLOC, to allocate the restricted DMA-bufs. This new IOCTL reaches the backend TEE driver, allowing it to choose how to allocate the restricted physical memory. TEE_IOC_RSTMEM_ALLOC is quite similar to TEE_IOC_SHM_ALLOC so it's tempting to extend TEE_IOC_SHM_ALLOC with two new flags TEE_IOC_SHM_FLAG_SECURE_VIDEO and TEE_IOC_SHM_FLAG_SECURE_TRUSTED_UI for the same feature. However, it might be a bit confusing since TEE_IOC_SHM_ALLOC only returns an anonymous file descriptor, but TEE_IOC_SHM_FLAG_SECURE_VIDEO and TEE_IOC_SHM_FLAG_SECURE_TRUSTED_UI would return a DMA-buf file descriptor instead. What do others think? This can be tested on QEMU with the following steps: repo init -u https://github.com/jenswi-linaro/manifest.git -m qemu_v8.xml \ -b prototype/sdp-v2 repo sync -j8 cd build make toolchains -j4 make all -j$(nproc) make run-only # login and at the prompt: xtest --sdp-basic https://optee.readthedocs.io/en/latest/building/prerequisites.html list dependencies needed to build the above. The tests are pretty basic, mostly checking that a Trusted Application in the secure world can access and manipulate the memory. There are also some negative tests for out of bounds buffers etc. Thanks, Jens [1] https://lore.kernel.org/lkml/20240830070351.2855919-1-jens.wiklander@xxxxxxxxxx/ [2] https://lore.kernel.org/dri-devel/20240515112308.10171-1-yong.wu@xxxxxxxxxxxx/ [3] https://lore.kernel.org/lkml/20220805135330.970-1-olivier.masse@xxxxxxx/ Changes since the V1 RFC: * Based on v6.11 * Complete rewrite, replacing the restricted heap with TEE_IOC_RSTMEM_ALLOC Changes since Olivier's post [2]: * Based on Yong Wu's post [1] where much of dma-buf handling is done in the generic restricted heap * Simplifications and cleanup * New commit message for "dma-buf: heaps: add Linaro restricted dmabuf heap support" * Replaced the word "secure" with "restricted" where applicable Jens Wiklander (2): tee: add restricted memory allocation optee: support restricted memory allocation drivers/tee/Makefile | 1 + drivers/tee/optee/core.c | 21 ++++ drivers/tee/optee/optee_private.h | 6 + drivers/tee/optee/optee_smc.h | 35 ++++++ drivers/tee/optee/smc_abi.c | 45 ++++++- drivers/tee/tee_core.c | 33 ++++- drivers/tee/tee_private.h | 2 + drivers/tee/tee_rstmem.c | 200 ++++++++++++++++++++++++++++++ drivers/tee/tee_shm.c | 2 + drivers/tee/tee_shm_pool.c | 69 ++++++++++- include/linux/tee_core.h | 6 + include/linux/tee_drv.h | 9 ++ include/uapi/linux/tee.h | 33 ++++- 13 files changed, 455 insertions(+), 7 deletions(-) create mode 100644 drivers/tee/tee_rstmem.c -- 2.43.0
