Student research poster: Network controller emulation on a sidecore for unmodified virtual machines

Paravirtual I/O devices are known to outperform emulated I/O devices but this performance improvement comes with two major drawbacks: Guest machine owners must install hypervisor-specific device drivers every time they switch hypervisors, and these device drivers must be implemented by the hypervisor providers for all major operating systems. Emulated devices do not suffer from these drawbacks because their drivers are implemented by the manufacturers of the bare-metal devices, and come preinstalled. We used optimizations from the virtio-net paravirtual network device combined with a sidecore to improve emulation of the E1000 network device in the QEMU hypervisor. Initial results show that the performance gap between emulated and paravirtual I/O devices is smaller than was previously thought. The small performance difference between paravirtual and emulated devices, along with the aforementioned advantages of the latter, makes emulation a natural choice when flexibility takes precedence over performance.