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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 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.
vdev-core.h
Definitions and functions that support vdev control functions and callbacks
guest_cpu_to_vrs()
Convert an error from a vCPU read or a vCPU write into a vdev return status value

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.
- 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.
  - Function Safety
    This section provides an overview of the restrictions that may apply when using the functions in this API.
  - aarch64/vmid.h
    Functions to access a guest's VMID (ARM)
  - abi.h
    Application binary interface (ABI) information
  - cdev.h
    Support routines for virtual character devices
  - firmware.h
    Functions for working with the firmware components of the VM presented to the guest
  - gasp.h
    Definitions and functions for working in guest address spaces
  - guest.h
    Controls for manipulating a guest system
  - hpci.h
    Host PCI interface for vdevs
  - hw_pci.h
    PCI support for vdevs
  - log.h
    Controls for logging messages
  - types.h
    vdev API base types
  - utils.h
    Miscellaneous utility functions
  - vdev-core.h
    Definitions and functions that support vdev control functions and callbacks
    - Definitions in vdev-core.h
      Preprocessor macro definitions for the vdev-core.h header file
    - guest_cpu_to_vrs()
      Convert an error from a vCPU read or a vCPU write into a vdev return status value
    - vdev_ctrl_assign_flags_t
      Data type for storing VDEV_CTRL_ASSIGN operation flags
    - vdev_ctrl_options_t
      Data type for representing vdev control options
    - vdev_factory
      Data structure used for creating new vdev instances
    - vdev_factory_flags_t
      Data type for storing flags controlling vdev creation
    - vdev_get_name()
      Build a human-readable name for a vdev
    - vdev_get_path()
      Fill in a buffer with a path identifying a vdev
    - vdev_pic_functions
      Extra information for PIC vdevs
    - vdev_pulse()
      Fill in a sigevent structure to invoke a vdev pulse routine
    - vdev_ref_status_t
      Data type for storing return status from vread and vwrite functions
    - vdev_register_factory()
      Add a virtual device (vdev) factory to the list of available vdev factories
    - vdev_register_for_system_pulse()
      Register a virtual device (vdev) to receive the specified pulse
    - vdev_s
      Virtual device (vdev) information
    - vdev_thread_create()
      Create a thread for a vdev
    - vdev_thread_create_func_t
      Prototype for function used to create threads
    - vdev_thread_setname()
      Set the name of a thread associated with a vdev
    - vdev_verify_unique()
      Assert that a vdev of the same type does not already exist
  - vio.h
    Definitions and functions for working with VIRTIO vdevs
  - vpci.h
    Controls for virtual PCI (vPCI) devices
  - wdog.h
    Constants, data types, and functions to support virtual watchdog devices
  - x86_64/apic.h
    Definitions for the virtual APIC bus (x86)
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.

guest_cpu_to_vrs()

Convert an error from a vCPU read or a vCPU write into a vdev return status value

Synopsis:

#include <qvm/vdev-core.h>

static vdev_ref_status_t guest_cpu_to_vrs(int errcode)

Arguments:

errcode: A value returned by a vCPU read or a vCPU write.

Description:

This function converts an error from a guest_cpu_read() or guest_cpu_write() function call into a vdev_ref_status_t value.

It is assumed that the returned value is an error.

Returns:

VRS_BUS_ERROR if errcode is -1; otherwise, VRS_ERRNO and the errcode value.

Page updated: March 14, 2026