Virtualizing ARM VFP (Vector Floating-Point) with Xen-ARM

VFP is a Vector Floating-Point unit in ARM processors. It enables ARM processors to handle auxiliary floating-point operations with hardware, which has become an essential part for performance in recent mobile devices. However, mobile virtualization such as Xen-ARM does not support virtual VFP, so floating point operations are very slow in mobile virtual machine. To overcome the performance limitation of floating-point operations in Xen-ARM virtualization, this paper presents a new virtual VFP so that applications can take the advantage of VFP hardware. With our virtual VFP, Xen-Linux reduces floating point operation latency up to one eighth from the existing software emulation version. In addition, result from mibench with virtual VFP presents 3-4 times higher throughput than that from software emulation. Furthermore, virtual VFP reduces code sizes and enhances power-efficiency.