MorphOS: An Extensible Networked Operating System

This paper introduces MorphOS, a novel, extensible networked operating system that addresses the runtime inflexibility of unikernels for dynamic, stateful network-intensive applications like Virtual Network Functions (VNFs). While unikernels offer superior performance and minimal resource overheads, their traditional update mechanisms require costly rebuilds and restarts, leading to service disruption and state loss. MorphOS addresses this by integrating eBPF to enable dynamic, verified code execution for seamless updates to packet processing logic. It employs an out-of-band verification service to offload computationally intensive verification tasks and utilizes hardware-assisted memory isolation (Memory Protection Keys) for enhanced execution hardening. Our evaluation of MorphOS with four VNF implementations demonstrates significant benefits: MorphOS drastically reduces reconfiguration time, effectively amortizes verification costs, and achieves up to 3× better performance compared to Linux-based VNF deployments, all while preserving the inherent lightweightness of unikernels. MorphOS thus paves the way for adaptable, efficient, and state-preserving networked applications in cloud environments.