From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C433B5D730; Fri, 23 Feb 2024 09:53:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708681994; cv=none; b=JYV+5JFyooQKy7XHUQmO9YzU5w3kmPNPwxicedr4pircr5kKqWb93z6XwGucONccoz7hD4gJweLqiBVilBnz7xlYgtWVszyydyoWDz0KiQfCKhqJhfA/r86ojFkjhiDAVq9VmRcklxaa3v7tGgTbr+9BHqa2iRtoOVdHyZhmJ5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708681994; c=relaxed/simple; bh=mEA7OXWofji3JL9y/tySpRMxEmSCep2gGBXCli4pK6E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=h6NFk8m4WFKomz46PlY/KkT/7ic5TqM1teB3F0M8Rt6X3Txhie8MPL4+dpHho5Wt2z5gexvUcnQ3OqCKh7NM8/ReihQ9MZiQAuc3Q1l9lY5JwfT/boFyJJPyIAzgAAsrXk/xkvGuqicTpNd6EhuoYD6rPVsqTGrkh0D+DCWY7qg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BC2CE15DB; Fri, 23 Feb 2024 01:53:50 -0800 (PST) Received: from mango.localdomain (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 423D23F766; Fri, 23 Feb 2024 01:53:10 -0800 (PST) From: Balint Dobszay To: op-tee@lists.trustedfirmware.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: jens.wiklander@linaro.org, sumit.garg@linaro.org, corbet@lwn.net, balint.dobszay@arm.com, sudeep.holla@arm.com, rdunlap@infradead.org, krzk@kernel.org, gyorgy.szing@arm.com Subject: [PATCH v2 3/3] Documentation: tee: Add TS-TEE driver Date: Fri, 23 Feb 2024 10:51:33 +0100 Message-Id: <20240223095133.109046-4-balint.dobszay@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240223095133.109046-1-balint.dobszay@arm.com> References: <20240223095133.109046-1-balint.dobszay@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add documentation for the Trusted Services TEE driver. Signed-off-by: Balint Dobszay --- Documentation/tee/index.rst | 1 + Documentation/tee/ts-tee.rst | 71 ++++++++++++++++++++++++++++++++++++ 2 files changed, 72 insertions(+) create mode 100644 Documentation/tee/ts-tee.rst diff --git a/Documentation/tee/index.rst b/Documentation/tee/index.rst index a23bd08847e5..4be6e69d7837 100644 --- a/Documentation/tee/index.rst +++ b/Documentation/tee/index.rst @@ -10,6 +10,7 @@ TEE Subsystem tee op-tee amd-tee + ts-tee .. only:: subproject and html diff --git a/Documentation/tee/ts-tee.rst b/Documentation/tee/ts-tee.rst new file mode 100644 index 000000000000..843e34422648 --- /dev/null +++ b/Documentation/tee/ts-tee.rst @@ -0,0 +1,71 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================= +TS-TEE (Trusted Services project) +================================= + +This driver provides access to secure services implemented by Trusted Services. + +Trusted Services [1] is a TrustedFirmware.org project that provides a framework +for developing and deploying device Root of Trust services in FF-A [2] S-EL0 +Secure Partitions. The project hosts the reference implementation of the Arm +Platform Security Architecture [3] for Arm A-profile devices. + +The FF-A Secure Partitions (SP) are accessible through the FF-A driver [4] which +provides the low level communication for this driver. On top of that the Trusted +Services RPC protocol is used [5]. To use the driver from user space a reference +implementation is provided at [6], which is part of the Trusted Services client +library called libts [7]. + +All Trusted Services (TS) SPs have the same FF-A UUID; it identifies the TS RPC +protocol. A TS SP can host one or more services (e.g. PSA Crypto, PSA ITS, etc). +A service is identified by its service UUID; the same type of service cannot be +present twice in the same SP. During SP boot each service in the SP is assigned +an "interface ID". This is just a short ID to simplify message addressing. + +The generic TEE design is to share memory at once with the Trusted OS, which can +then be reused to communicate with multiple applications running on the Trusted +OS. However, in case of FF-A, memory sharing works on an endpoint level, i.e. +memory is shared with a specific SP. User space has to be able to separately +share memory with each SP based on its endpoint ID; therefore a separate TEE +device is registered for each discovered TS SP. Opening the SP corresponds to +opening the TEE device and creating a TEE context. A TS SP hosts one or more +services. Opening a service corresponds to opening a session in the given +tee_context. + +Overview of a system with Trusted Services components:: + + User space Kernel space Secure world + ~~~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~ + +--------+ +-------------+ + | Client | | Trusted | + +--------+ | Services SP | + /\ +-------------+ + || /\ + || || + || || + \/ \/ + +-------+ +----------+--------+ +-------------+ + | libts | | TEE | TS-TEE | | FF-A SPMC | + | | | subsys | driver | | + SPMD | + +-------+----------------+----+-----+--------+-----------+-------------+ + | Generic TEE API | | FF-A | TS RPC protocol | + | IOCTL (TEE_IOC_*) | | driver | over FF-A | + +-----------------------------+ +--------+-------------------------+ + +References +========== + +[1] https://www.trustedfirmware.org/projects/trusted-services/ + +[2] https://developer.arm.com/documentation/den0077/ + +[3] https://www.arm.com/architecture/security-features/platform-security + +[4] drivers/firmware/arm_ffa/ + +[5] https://trusted-services.readthedocs.io/en/v1.0.0/developer/service-access-protocols.html#abi + +[6] https://git.trustedfirmware.org/TS/trusted-services.git/tree/components/rpc/ts_rpc/caller/linux/ts_rpc_caller_linux.c?h=v1.0.0 + +[7] https://git.trustedfirmware.org/TS/trusted-services.git/tree/deployments/libts/arm-linux/CMakeLists.txt?h=v1.0.0 -- 2.34.1