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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
vio.h
Definitions for VIRTIO vdevs

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
    - Definitions in vio.h
      Preprocessor macro definitions for the vio.h header file
    - vio_append_iov()
      Extend an iov array to cover an additional VIRTIO descriptor
    - vio_append_iov_cap()
      Extend an iov array to cover an additional VIRTIO descriptor, up to a maximum length
    - vio_config_update()
      Inform the driver that the device has modified its configuration
    - vio_control_status()
      Function called by the control function to output the vdev's status information
    - vio_ctrl_pci_bars()
      Handle VDEV_CTRL_PCI_BARS for vdevs
    - vio_description
      Information describing the VIRTIO device to be created
    - vio_device_status()
      Update the VIRTIO status register for the device
    - vio_get_iov()
      Convert a VIRTIO descriptor request into an iov array
    - vio_init()
      Initialize the vdev's state
    - vio_init_queue()
      Initialize a single virtqueue in the device
    - vio_iov
      Structure for converting a virtqueue descriptor list into an iov_t array
    - vio_iov_flags
      Flag specifying if a host-physical address is required
    - vio_iov_set_flags()
      Handle setting or clearing flags in a vio_iov structure
    - vio_prepare_iov()
      Set the required fields for one logical sequence of calls to vio_append_iov()
    - vio_put_iov()
      Finish handling a VIRTIO request
    - vio_queue_info
      Information for one virtqueue on the device
    - vio_read()
      Handle a read reference for a vdev
    - vio_reset()
      Re-initialize the device
    - vio_setup_queues()
      Get host virtual addresses for the virtqueue rings
    - vio_state
      State of a VIRTIO vdev
    - vio_version
      Version of the VIRTIO standard the device is implementing
    - vio_write()
      Handle a write reference for a vdev
  - vpci.h
    Definitions for virtual PCI devices
  - 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.

vio.h

Definitions for VIRTIO vdevs

For more information about the VIRTIO specification, see OASIS at oasis-open.org.

Function safety

All functions that vio.h provides are thread safe.


Function	When used	Notes
vio_append_iov()	Running
vio_config_update()	Running
vio_ctrl_pci_bars()	Startup	Use only on VDEV_CTRL_PCI_BARS.
vio_device_status()	Running
vio_get_iov()	Running
vio_init()	Startup
vio_init_queue()	Startup, running
vio_iov_set_flags()	Running
vio_prepare_iov()	Running
vio_put_iov()	Running
vio_read()	Running	Typically used in vread().
vio_reset()	Running
vio_setup_queues()	Running
vio_write()	Running	Typically used in vwrite().

Page updated: March 12, 2026