Virtuoso: High Resource Utilization and μs-scale Performance Isolation in a Shared Virtual Machine TCP Network Stack

Virtualization improves resource efficiency and ensures security and performance isolation for cloud applications. Today, operators use a layered architecture with separate network stack instances in each VM and container connected to a virtual switch. Decoupling through layering reduces complexity, but induces performance and resource overheads at odds with increasing demands for network bandwidth, connection scalability, and low latency. We present Virtuoso, a new software network stack for VMs and containers. Virtuoso re-organizes the network stack to maximize CPU utilization, enforce isolation, and minimize processing overheads. We maximize utilization by running one elastically shared network stack instance on dedicated cores; we enforce isolation by performing central and fine-grained per-packet resource accounting and scheduling; we reduce overheads by building a single-layer data path with a one-shot fast-path incorporating all processing from the TCP transport layer through network virtualization and virtual switching. Virtuoso improves resource efficiency by up to 82 other virtualized network stacks without sacrificing isolation, and keeps processing overhead within 6.7