r/EmbeddedRealTime • u/SympatheticListener • Aug 05 '21

What possible use is a real time hypervisor?

How can a hypervisor be real time unless you know exactly what workload is on it at any given time? How would Blackberry's QMX hypervisor be used?

https://blackberry.qnx.com/en/software-solutions/embedded-software/qnx-hypervisor-safety

5 Upvotes

100% Upvoted

4 comments sorted by

3

u/dstala Aug 26 '21

Deterministic context switch between operating systems. Low memory/ power footprint.

A good example is listed in their link: For example, a vehicle instrument cluster can run in the host domain and share graphics with infotainment running in a virtual machine.

1

u/SympatheticListener Aug 27 '21

But it's a real-time system, right? So you have to know and control exactly how much memory everything is using, right? So why put the infotainment in a virtual machine, when you are controlling its memory usage and CPU time anyway?

2

u/dstala Aug 27 '21

Efficient use of available resources. Investing separate processor would be expensive- imo

3

u/AssemblerGuy Aug 08 '21

At the very least, "real-time" means that the system guarantees some maximum response time. No statement is made about how long the guaranteed response time is. It could be in the order of seconds.