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QNX Hypervisor and QNX Hypervisor for Safety
The QNX Hypervisor and QNX Hypervisor for Safety products allow you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
Virtual Device Developer's Guide
The Virtual Device Developer's Guide is intended for use by developers writing virtual devices (vdevs) in a QNX hypervisor system.
About Writing Virtual Devices
This chapter explains the concepts you need to understand before you start writing virtual devices (vdevs) for a QNX hypervisor system.
Integrating a vdev
After you have written the code for your vdev, you must add it to your hypervisor system.

QNX Momentics IDE User's Guide
This User's Guide describes version 8.0 of the Integrated Development Environment (IDE) that's part of the QNX Tool Suite.
QNX Software Development Platform
QNX SDP is a cross-compiling and debugging environment, including an IDE and command-line tools, for building binary images and programs for target boards running the QNX OS 8.0.
QNX Software in the Cloud
QNX Software in the Cloud enables developers to use the QNX software in Amazon Web Services (AWS) and Microsoft Azure (Azure).
QNX Toolkit for Visual Studio Code
This User's Guide describes the QNX^® Toolkit for Visual Studio Code. The guide introduces you to the QNX Toolkit by explaining the QNX development environment and how to build, run, and debug your QNX^® Operating System (OS) applications and systems.
QNX Hypervisor and QNX Hypervisor for Safety
The QNX Hypervisor and QNX Hypervisor for Safety products allow you to run multiple OSs on a target system so you can separate critical and non-critical functions, support a wide variety of applications, and reduce hardware costs.
- User's Guide
  This User's Guide explains the QNX hypervisor architecture and provides instructions for installing and running a QNX hypervisor system, changing system components and configuration, and using hypervisor features such as virtual devices (vdevs).
- Virtual Device Developer's Guide
  The Virtual Device Developer's Guide is intended for use by developers writing virtual devices (vdevs) in a QNX hypervisor system.
  - About Writing Virtual Devices
    This chapter explains the concepts you need to understand before you start writing virtual devices (vdevs) for a QNX hypervisor system.
    - Prerequisites
      Before you write your own vdev you should understand what a vdev is so that you know what it is you are writing.
    - Designing a vdev
      Before you begin writing a vdev, you should decide what you need the vdev to do.
    - Integrating a vdev
      After you have written the code for your vdev, you must add it to your hypervisor system.
    - Lifecycle of a vdev
      Here is an overview of the lifecycle of a vdev, from initialization to termination.
    - Guest memory regions
      Use the functions defined in gasp.h to work with memory regions in the guest's physical address space.
    - Reading and writing in a vdev
      When a guest reads from or writes to a vdev, the vdev must perform actions analogous to the actions that hardware performs in response to reads and writes.
    - Terminating qvm process instances and guests
      The method you use in your vdev to terminate a qvm process instance (and, hence, any running guest) depends on the status of the guest.
    - Debugging a vdev
      You can use the same techniques to debug a vdev as you use to debug other code in a QNX OS system.
  - The Basics: vdev trace
    This simple vdev illustrates how to implement basic vdev functionality.
  - Advanced Topics
    This chapter presents examples of more advanced vdevs implemented with QNX hypervisors.
- Virtual Device Developer's API Reference
  The Virtual Device Developer's API Reference presents the QNX hypervisor public virtual device (vdev) API. It is intended for use by developers writing virtual devices (vdevs) in a QNX hypervisor system.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation, explains how to obtain technical support, and provides some information about licensing.

Integrating a vdev

After you have written the code for your vdev, you must add it to your hypervisor system.

Adding a vdev to your hypervisor system

For up-to-date instructions on adding a vdev to your hypervisor system, go to the QNX Hypervisor GitLab Repository at https://gitlab.com/qnx/hypervisor.

Note:

A qvm process uses the standard shared object mechanisms and environment variables. For example, you can use LD_LIBRARY_PATH to set the search path, and DL_DEBUG to set the debug level (see Setting PATH and LD_LIBRARY_PATH in the QNX OS User's Guide and Diagnostics and debugging in the Programmer's Guide).

If your vdev emulates a physical device (e.g., vdev pl011), your guest OS may already have a device driver that will work with the vdev. If your guest doesn't have such a driver, you will need to write one and include it in your guest. For QNX guests, refer to the QNX OS documentation; for other guests, refer to the appropriate documentation for those OSs.

We recommend that you start with one of the vdev examples available in the GitLab repository mentioned above, go through the steps described therein to add it to your system, and confirm that everything works as expected. Our examples work, so you can focus on making sure that you know how to implement a vdev. Then, when you have your own vdev ready to test, adding the vdev to your system and configuring the VM will be familiar tasks.

Compiling a vdev

If you compile a vdev using the QNX recursive makefile structure, you need vdev/common.mk, vdev/Makefile, and the entire vdev/name directory (e.g., vdev/trace). For more information about this makefile structure, see the Conventions for Recursive Makefiles and Directories chapter in the QNX OS Programmer's Guide.

This build system is just one way of compiling a vdev; you can use another system if you prefer.

Documented procedures showing how to compile in Windows and Linux are provided within the vdev source code section of the GitLab repository.

Page updated: March 14, 2026