The Taub Faculty of Computer Science Events and Talks

Hypervisors implement useful features such as live migration and software-defined networking by interposing on their guest virtual machines’ I/O activity. Unfortunately, this interposition significantly reduces performance and scalability due to competition for resources between multiple guests and costly host/guest context switches. We present an efficient and scalable software-based I/O virtualization system that provides all of the benefits of I/O interposition while running host functionality on separate cores dedicated to serving multiple guests’ I/O. We find that two dedicated cores can interpose on the I/O activity of up to 14 I/O-intensive guests with performance that is 1.2x–3x better than the baseline, in some cases exceeding the performance of hardware-based I/O virtualization.

Authors: Nadav Har’El, Abel Gordon, and Alex Landau, IBM Research–Haifa; Muli Ben-Yehuda, IBM Research–Haifa and Technion IIT; Avishay Traeger and Razya Ladelsky, IBM Research–Haifa Based on the tech report located at: http://domino.research.ibm.com/library/cyberdig.nsf/1e4115aea78b6e7c85256b360066f0d4/479e3578ed05bfac85257b4200427735!OpenDocument&Highlight=0,h-0319