Porting the QEMU virtualization software to MINIX 3 Master's thesis in Computer Science Erik van der Kouwe Student number 1397273
[email protected] Vrije Universiteit Amsterdam Faculty of Sciences Department of Mathematics and Computer Science Supervised by dr. Andrew S. Tanenbaum Second reader: dr. Herbert Bos 12 August 2009 Abstract The MINIX 3 operating system aims to make computers more reliable and more secure by keeping privileged code small and simple. Unfortunately, at the moment only few major programs have been ported to MINIX. In particular, no virtualization software is available. By isolating software environments from each other, virtualization aids in software development and provides an additional way to achieve reliability and security. It is unclear whether virtualization software can run efficiently within the constraints of MINIX' microkernel design. To determine whether MINIX is capable of running virtualization software, I have ported QEMU to it. QEMU provides full system virtualization, aiming in particular at portability and speed. I find that QEMU can be ported to MINIX, but that this requires a number of changes to be made to both programs. Allowing QEMU to run mainly involves adding standardized POSIX functions that were previously missing in MINIX. These additions do not conflict with MINIX' design principles and their availability makes porting other software easier. A list of recommendations is provided that could further simplify porting software to MINIX. Besides just porting QEMU, I also investigate what performance bottlenecks it experiences on MINIX. Several areas are found where MINIX does not perform as well as Linux. The causes for these differences are investigated.