(1) ACE leverages hardware virtualization support, including an MMU, to enable confidential virtual machines. In contrast, Keystone is designed for simpler processors that rely on just machine/supervisor/user privilege levels and physical memory protection (PMP), making it more suitable for process-based enclaves—similar to architectures like Komodo or Intel SGX. In that sense, ACE is conceptually closer to Intel TDX, but tailored for a different domain: embedded systems rather than cloud infrastructure.
(2) In ACE, the architecture and code are simplified to facilitate formal verification.
(1) ACE leverages hardware virtualization support, including an MMU, to enable confidential virtual machines. In contrast, Keystone is designed for simpler processors that rely on just machine/supervisor/user privilege levels and physical memory protection (PMP), making it more suitable for process-based enclaves—similar to architectures like Komodo or Intel SGX. In that sense, ACE is conceptually closer to Intel TDX, but tailored for a different domain: embedded systems rather than cloud infrastructure.
(2) In ACE, the architecture and code are simplified to facilitate formal verification.