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QNX Hypervisor 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).
VM Configuration Reference
When you specify options to configure a qvm process, you are assembling and configuring the components of a virtual machine (VM) in which a guest will run.
set
Set the value of a configuration variable

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 OS in the Amazon cloud environment.
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 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).
- Understanding QNX Virtual Environments
  QNX hypervisors are designed to meet the expectations of a hypervisor specified by the Popek/Goldberg Theorem.
- QNX Hypervisor: Protection Features
  This chapter explains the main features used by the QNX Hypervisor to protect itself and its guests. Many of these features are part of the design, while others are configurable.
- Configuration
  A QNX hypervisor, its qvm processes that create the VMs in which guests run, and these guests must be configured to work together.
- Building a QNX Hypervisor System
  This chapter explains how to build (assemble) a QNX Hypervisor system and transfer a bootable image to a supported target platform.
- Booting and Shutting Down
  This chapter describes how to boot and shut down the hypervisor host and guests in a QNX hypervisor system.
- Using Virtual Devices, Networking, and Memory Sharing
  This chapter describes how guests can discover and connect to vdevs and how they can use important hypervisor capabilities, such as networking and memory sharing.
- Monitoring and Troubleshooting
  This chapter describes some tools and techniques you can use to monitor and troubleshoot your hypervisor system.
- Performance Tuning
  This chapter describes common sources of overhead in a QNX hypervisor system, and strategies for reducing this overhead and optimizing system performance.
- VM Configuration Reference
  When you specify options to configure a qvm process, you are assembling and configuring the components of a virtual machine (VM) in which a guest will run.
  - Configuration variables
    You can set configuration variables that affect qvm process instance, guest, CPU, and vdev behavior.
  - cmdline
    Pass a string to a guest as though the string had been entered from the command line
  - cpu
    Create a new vCPU in the VM
  - dryrun
    Initialize a VM without starting the guest
  - dump
    Write a dump file for the guest
  - generate
    Explicitly request the generation of the specified system information table type in the guest
  - load
    Copy the contents of a file into the guest system address space
  - logger
    Filter messages to the output, and specify the location where these messages are output
  - pass
    Configure physical devices or data blob types passed through from the host to a guest
  - ram
    Allocate RAM to the VM
  - reserve
    Reserve specified locations in guest-physical memory and/or guest interrupts
  - rom
    Allocate ROM to the VM
  - set
    Set the value of a configuration variable
  - suppress
    Explicitly request the suppression or generation of the specified system information table type in the guest
  - system
    Specify the name of the VM being configured by the present configuration file
  - tolerance
    Set how long the host system is allowed to delay notifying the hypervisor of a timer expiry
  - unsupported
    Specify what the hypervisor should do if it can't successfully complete the emulation of a guest instruction
  - user
    Assign the specified values to the user name, or to the user ID and group IDs of the qvm process instance
  - vdev
    Specify and configure a virtual device to include in the VM
- Virtual Device Reference
  This chapter presents the virtual devices (vdevs) delivered with QNX hypervisors, and describes how to configure these vdevs.
- Virtual Machine Firmware
  The virtual machines (VMs) in a QNX Hypervisor system provide a comprehensive firmware interface for guest OSs to manage VM power settings, access timers, and more.
- Utilities and Drivers Reference
  This chapter describes the utilities and drivers delivered with the QNX hypervisor.
- Terminology
  The following terms are used throughout the QNX hypervisor documentation.
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.

set

Set the value of a configuration variable

Synopsis:

set var val

Options:

The set option supports the following variable types:

address — use any of the forms permitted for memory sizes when you specify val (e.g., 4K, 0d16384); for more information, see About notation
boolean — any of the following values are equivalent; the first term turns on the feature, the second turns it off: on/off, 1/0, yes/no, true/false
tristate — the following values are permitted:
- on — the feature is always on
- off — the feature is always off
- auto — the feature's setting is automatically detected by qvm
number — any positive integer that can be expressed with 64 bits; decimal notation (no prefix) and hexadecimal notation (prefixed with 0x) are permitted; for more information, see About notation
string — a text string, used as is

Note:

For descriptions of all variables (i.e., var values) supported on a given platform, including the variable types (i.e., possible val values), see Configuration variables.

Description:

Each set var val argument pair defines a variable setting that applies to an implicit context. This is different than the VM configuration file notion of a context, which is a group of related configuration options (for details, see Contexts in the VM configuration syntax topic). The implicit context to which each variable applies is noted in its description. Supported implicit contexts include:

global — applies to the VM (qvm process instance) currently being configured
CPU — applies to the vCPU currently being configured
vdev — applies to the vdev currently being configured

You can display information on the currently permitted variables. For example, in a shell prompt in the host, type:

# qvm set ?

You should see the variable names along with their types and contexts in a listing like the following:

allowed set variables
    legacy-free                    (boolean, global)
    message-block-timeout          (number, global)
    posted-interrupts              (boolean, global)
    virtual-interrupts             (boolean, global)

A question mark (?) is a shell wildcard character, so you may need to escape it. If a vdev defines its own variables, ? will list these only after a vdev option has loaded the vdev where these variables are specified.

Page updated: August 11, 2025