Network I/O Path Analysis in the Kernel-Based Virtual Machine Environment through Tracing

Virtualization is experiencing a resurgence of interest for diverse uses including server consolidation and shared hosting. Unfortunately, the overhead of virtual machine network I/O has became the main factor that affects the performance of the virtual machine. Meanwhile, few tools are currently available to help debug performance problems in virtual machine environments. Therefore, it is especially significant to analyze Virtual Machine network I/O path and then improve the performance. Firstly, we analyze the Kernel-based Virtual Machine (KVM) and its network I/O architecture. Then the tracing tool SystemTap and tracing technology in virtual machine are described. This paper presents in detail the ingressing path and the corresponding overhead in the environment of KVM through tracing. The bottlenecks that affect the performance of network virtualization in KVM are also summarized to make future optimizing work easier.