Flexible NVMe Request Routing for Virtual Machines

Recent advances in storage hardware have resulted in massive improvements in both I/O latency and throughput.However, existing storage virtualization tools either depend on a heavy and inefficient I/O stack that is not optimized for parallelism, or require a separate API that is difficult to manage and monitor.In this work, we introduce NVMetro, a solution based on the NVMe protocol that proposes a flexible choice between multiple I/O paths to ease the development of adaptive and performant virtual storage.NVMetro provides two components:(1) an intelligent I/O classification and routing framework powered by eBPF; and (2) an easy-to-use and performant API to assist the creation of userspace I/O functions within our framework.We demonstrate the benefits of NVMetro by implementing two virtual storage functions, and we evaluate them using various benchmarks.The obtained results show that NVMetro achieves a performance and scalability comparable to bleeding-edge, kernelbypass technologies while retaining the flexibility of traditional OS-based storage APIs. UIF Classifier RouterNVMetro