ISOLATING MEMORY WITHIN TRUSTED EXECUTION ENVIRONMENTS

摘要

Example methods and systems are directed to isolating memory in trusted execution environments (TEEs). In function-as-a-service (FaaS) environments, a client makes use of a function executing within a TEE on a FaaS server. To minimize the trusted code base (TCB) for each function, each function may be placed in a separate TEE. However, this causes the overhead of creating a TEE to be incurred for each function. As discussed herein, multiple functions may be placed in a single TEE without compromising the data integrity of each function. For example, by using a different extended page table (EPT) for each function, the virtual address spaces of the functions are kept separate and map to different, non-overlapping physical address spaces. Partial overlap may be permitted to allow functions to share some data while protecting other data. Memory for each function may be encrypted using a different encryption key.