by Guest on 2015-01-13 12:35:56
Guest operating systems running over the virtual machines share a variety of resources.
Since CPU is allocated in a time division manner it consequently leads them to having the unknown
physical time. It is not regarded as a serious problem in the server virtualization fields. However, it
becomes critical in embedded systems because it prevents guest OS from executing real time tasks
when it does not occupy CPU. In this paper we propose a hypercall to register a timer service to notify
the timer request related real time. It enables hypervisor to schedule a virtual machine which has real
time tasks to execute, and allows guest OS to take CPU on time to support real time. The following
experiment shows its implementation on Xen-Arm and para-virtualized Linux. We also analyze the
real time performance with response time of test application and frames per second of Mplayer.