Bringing Together Cross-ISA Checkpoint/Restoration and AOT Compilation of WebAssembly Programs

Cross-instruction set architecture (ISA) checkpoint/restoration is becoming increasingly important for live migration in heterogeneous computing environments, where applications need to move seamlessly between ARM, x86, and other processor architectures. While existing approaches either require compilation without Control-flow Integrity (CFI) or suffer from significant performance overhead through interpreter-based execution, this paper presents a novel approach that enables efficient cross-ISA migration using instrumentation during ahead-of-time (AOT) compilation. Our key insight is that on-stack replacement (OSR) enables cross-ISA checkpoint/restoration. OSR is a technique for JIT compilers, and we leverage it to transform between ISA-dependent machine states and ISA-independent WebAssembly states. Our other notable contribution is a technique enabling checkpointing without disabling modern CPU security features such as CFI. We implement the proposed techniques in Wanco, a WebAssembly AOT compiler supporting Linux on ARM-v8 and x86-64 architectures. Our evaluation demonstrates that Wanco achieves efficient cross-ISA migration compared to CRIU, a standard Linux process migration tool. Wanco reduces checkpoint time by 1.0–5.1 times and snapshot size by 1.1–25 times, while incurring an average execution-time overhead of 36 %.