Home
QNX Hypervisor
The QNX Hypervisor allows 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.
QNX Hypervisor for Safety Virtual Device Developer's API Reference
vpci.h
Definitions for virtual PCI devices
vpci_region_update()
Update the hosting qvm process instance with new BAR regions

QNX Momentics IDE User's Guide
This User's Guide describes version 7.1 of the Integrated Development Environment (IDE) that's part of the QNX Momentics 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 QNX Neutrino 7.1.
QNX Hypervisor
The QNX Hypervisor allows 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.
- QNX Hypervisor for Safety User's Guide
- QNX Hypervisor for Safety Virtual Device Developer's Guide
- QNX Hypervisor for Safety Virtual Device Developer's API Reference
  - Function Safety
    This section provides an overview of the restrictions that may apply when using the functions in this API.
  - aarch64/vmid.h
    Definitions to access a guest's VMID (ARM)
  - abi.h
    Application binary interface (ABI) version of the vdev API
  - cdev.h
    Functions to create virtual character devices for guests
  - firmware.h
    Functions for working with the firmware components of the VM presented to the guest
  - gasp.h
    Functions for working in guest address spaces
  - guest.h
    Definitions for manipulating a guest system
  - hpci.h
    Host PCI interface for vdevs
  - hw_pci.h
    PCI support for vdevs
  - outpipe.h
    Definitions for the output pipe (outpipe)
  - types.h
    vdev API base types
  - utils.h
    Miscellaneous utility functions
  - vdev.h
    Source compatibility header file
  - vdev-core.h
    Definitions for vdevs
  - vio.h
    Definitions for VIRTIO vdevs
  - vpci.h
    Definitions for virtual PCI devices
    - Definitions in vpci.h
      Preprocessor macro definitions for the vpci.h header file
    - vpci_bar
      The state of a specified PCI BAR
    - vpci_bar_base()
      Return the base address of the specified BAR
    - vpci_bar_writable()
      Generate the writable field for the slice descriptor of a BAR
    - vpci_cfg_read()
      Handle a read from a PCI configuration space register
    - vpci_cfg_write()
      Handle a write to the PCI configuration space
    - vpci_ctrl_pci_bars()
      Handle VDEV_CTRL_PCI_BARS on behalf of a virtual PCI device
    - vpci_init_rw()
      Initialize the read and write state of a virtual PCI device
    - vpci_region_update()
      Update the hosting qvm process instance with new BAR regions
    - vpci_rw_state
      Read and write configuration states for a virtual PCI device
    - vpci_update_bars()
      Update the hosting qvm process instance with new BAR information for the specified BAR or BARs
  - wdog.h
    Definitions to support virtual watchdog devices
  - x86_64/apic.h
    Definitions for the virtual APIC bus (x86)
- QNX Hypervisor User's Guide
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 Advanced Virtualization Frameworks User's Guide
This User's Guide is aimed at all systems integrators and developers who want to design and build embedded systems using the QNX Advanced Virtualization Frameworks.
Typographical Conventions, Support, and Licensing
This section describes the typographical conventions used throughout the documentation and explains how to obtain technical support.

vpci_region_update()

Update the hosting qvm process instance with new BAR regions

Synopsis:

#include <qvm/vpci.h>

void vpci_region_update(vdev_t *vdp,
                        struct vpci_rw_state *rw_cfg)

Arguments:

vdp: A pointer to the virtual PCI device.
rw_cfg: A pointer to the devie's read/write configuration data.

Description:

Call this function when the guest has changed a BAR (i.e., the update should be done after the regions were modified by the guest).

Page updated: March 12, 2026