Building guests

When you build guests to run in a QNX virtualized environment, you must build them for the appropriate hardware architecture, and configure the VMs in which they will run.

You need to have the build environment and tools that correspond to the hypervisor and the guests you're building (see “Supported build environments”).

Validate the guests without the hypervisor

It is much easier to identify and debug problems on a non-virtualized system than on a system running a hypervisor. If possible, before you add a guest to your hypervisor system, you should build and test it running directly on the hardware.

  1. If you're building a QNX guest, follow the instructions in the BSP User’s Guide to build the BSP for your hardware platform and copy it to your target.

    For a non-QNX guest, follow the instructions for building that guest and copy it to your target.

  2. Boot your system and make sure it runs as required.

    In particular, make sure that all devices you'll configure as pass-through devices to a guest are functioning properly. Problems with these devices are easier to resolve in a non-virtualized system than in a system with a hypervisor.

  3. Repeat for each of the OSs you'll run as a guest in your hypervisor system.

When you're satisfied that all OSs you'll run as guests function as required in a non-virtualized system, you can add them to your hypervisor system image and copy them to your target to run as guests.

Note:

It may not always be possible to test a guest without the hypervisor (i.e., running directly on the hardware). For example:

  • The guest may use para-virtualized devices, which by definition don't exist as hardware.
  • The startup driver required for the guest may not work directly on the board; this can usually be corrected by changing the buildfile for the guest to (temporarily) use the appropriate driver for starting up directly on the board.

Supported guest formats in images

The hypervisor can launch guests placed on the system as bootable images in the following formats:

Configuring the VMs

Each guest in a hypervisor system is hosted in a hypervisor qvm process. When it is started, each instance of the qvm process reads its specified configuration file and assembles a VM from the components specified in this file. This VM becomes the virtual environment in which the guest runs.

If you change anything in your guest that accesses hardware (physical or virtual), you need to ensure that the qvm configuration file for the VM that will host the guest is properly configured.

When building a guest to run in a QNX virtualized environment, it is important to remember that each guest must be configured to match the VM in which it will run. This means that it must have the drivers it needs to access devices, whether they are physical or virtual. In the VM, the drivers must be configured to be where the guest expects them to be.

In a QNX OS system, board-specific drivers and other components are brought into the build through BSPs. This is true for a QNX OS that will run in a VM, just as it is for a QNX OS that will run directly on hardware.

For both ARM and x86 hardware platforms, you'll need the BSP for your supported hardware platform to build the hypervisor host domain, and a hypervisor guest BSP to build each guest. These are available for QNX Neutrino 7.1 and QOS 2.2.1 guests. If you add new devices for your guest, you'll probably need to add the appropriate new drivers to the BSPs, and rebuild the guest with them.

What is true for QNX guests is also true for non-QNX guests: the VM must present to the guest the virtual environment the guest OS expects to find (i.e., the hardware components it has been built to use). The only difference is that QNX OSs (including QNX OSs that will run as guests in virtualized environments) use BSPs to bring in the architecture-specific and board-specific components, while other OSs may use other mechanisms to achieve the same end.

For more information, see “Assembling and configuring VMs” in the “Configuration” chapter.