SR-IOV Based Network Interrupt-Free Virtualization with Event Based Polling

摘要

Along with the developments of networking and virtualization technologies, high speed network connections have become one of the key components in cloud computing and data-centers. Single-Root I/O Virtualization (SR-IOV) enhances the network throughput to the extent of becoming close to the line rate and achieving high scalability in the 10Gbps and higher network environments. However, the overhead of SR-IOV interrupt virtualization remains significant due to some additional trap-and-emulation overhead on the virtual interrupt controller. The higher the virtualization network connection is, the higher the interrupt frequency becomes through high bandwidth network. To mitigate this problem, we propose a smart Event-Based Polling model (sEBP), which leverages existing system events to trigger a regular packet polling such that network interrupts are eliminated from the critical I/O paths in the virtual environment. Due to the many varieties of system events, sEBP can deal with the network workload in a configurable and flexible manner. Based on a hierarchical virtualized environment, it can also be implemented either at the guest OS kernel level or at the Virtual Machine Manager (VMM) level. Since polling is much lighter than interrupt processing, sEBP significantly reduces the network processing overhead. The experimental results prove the efficiency of sEBP, which can achieve up to a 59% performance improvement and a 23% improved scalability ratio.