TS-Perf: General Performance Measurement of Trusted Execution Environment and Rich Execution Environment on Intel SGX, Arm TrustZone, and RISC-V Keystone

Abstract

A trusted execution environment (TEE) is a new hardware security feature that is isolated from a normal OS (i.e., rich execution environment (REE)). The TEE enables us to run a critical process, but the behavior is invisible from the normal OS, which makes it difficult to debug and tune the performance. In addition, the hardware/software architectures of TEE are different on CPUs. For example, Intel SGX allows user-mode only, although Arm TrustZone and RISC-V Keystone run a trusted OS. In addition, each TEE has each SDK for programming. Each SDK offers own APIs and makes difficult to write a common program. These features make it difficult to compare the performance fairly between TEE and REE on different CPUs. To obtain precise performance and behavior in TEE, we propose TS-perf which is a compiler-based performance measurement method. TS-perf accesses the hardware timestamp counter in TEE as well as REE and keeps a precise log. The codes for measurement are inserted in a TEE binary by the compiler options (i.e., profile option, constructor, and destructor). Furthermore, we utilize the separate compilation technique, and the same benchmark binary is used for a fair comparison between TEE and REE. The architecture of TS-perf is general and implemented for three TEE architectures (Arm TrustZone, Intel SGX, and RISC-V Keystone). TS-perf measures the performance of GlobalPlatform’s TEE internal APIs, matrix multiplication, memory access, and storage access. The comparisons show the difference in performance between TEE and REE and the unusual behavior of trusted applications (TAs).