https://xenproject.org/2015/02/02/getting-started-with-freertos-for-xen-on-arm-2/
For now, we have had some success getting real-time behavior by simply pinning real-time domains to one CPU on a multi-CPU system.
git clone https://github.com/GaloisInc/FreeRTOS-Xen.githttps://github.com/GaloisInc/FreeRTOS-Xen
https://www.youtube.com/watch?v=yDs7aNFcnIM
XEN HYPERCALLS
A hypercall is to a syscall what a hypervisor is to an OS.
https://elixir.bootlin.com/linux/latest/source/include/xen/arm/hypercall.h
https://xenbits.xen.org/docs/unstable/hypercall/arm/index.html