About This Guide
The Virtual Device Developer's Guide is intended for use by developers writing virtual devices (vdevs) in a QNX hypervisor system.
This guide should be used in conjunction with the following hypervisor documents:
This guide begins by explaining all you need to know before you can write your own fully functional vdevs. It then provides a detailed example of defining a basic vdev (the trace vdev) for your hypervisor system, walking through the code needed for the vdev to configure and register itself with the virtual machine (VM) and to respond to requests from the guest. This guide then provides examples of more advanced vdevs that emulate hardware watchdogs (e.g., wdt-sp805) or implement virtualized devices that follow the VIRTIO standard.
Each provided example builds on the information presented with previous examples. We don't repeat information already presented with a previous example; for instance, in the discussion of vdev wdt-sp805 we don't explain a vdev's startup stage because that topic is already covered with vdev trace.
QNX hypervisor variants
QNX hypervisors are available in two variants: QNX Hypervisor and QNX Hypervisor for Safety. The User's Guide explains the different use cases for these two variants and lists their latest releases.
The QNX virtual device toolkit does not automatically produce safety-certified vdevs. If you are working with the QNX Hypervisor for Safety and developing a system that will be safety-certified, it is your responsibility to develop your vdevs in the appropriate environment and to see them through safety certification.
If you require assistance, contact your QNX technical support representative.
Throughout all guides, when discussing any concepts, features, or instructions that apply
to both the non-safety and safety products, we use the terms QNX hypervisor
(with a small h
) and hypervisor to refer to both hypervisor variants.
In general, the content in our user documentation applies to both variants except where
explicitly indicated.
What's in this guide
| To find out about: | See: |
|---|---|
| Information about writing a vdev in a QNX hypervisor system | About Writing Virtual Devices |
| A simple vdev example | The Basics: vdev trace |
| Vdevs that emulate hardware | Advanced Topics |
| Para-virtualized devices that use VIRTIO | Para-virtualized devices |
Source code for sample vdevs
The source code for the vdevs discussed in this guide is available in the QNX Hypervisor GitLab Repository at https://gitlab.com/qnx/hypervisor.
Copyright notice
Copyright © 2019–2026, BlackBerry Limited. All rights reserved.