Devices
A QNX hypervisor provides guests with access to physical devices, including pass-through and shared devices, and virtual devices, including emulation and para-virtualized devices.
About device access
When you configure your QNX virtualized environment (the hypervisor, the qvm processes for the virtual machines, and the guests), you need to assign physical devices and virtual devices (vdevs) to the hypervisor and to the guests. To do this properly you need to know not just if a device is a physical or virtual device, but also the type of physical or virtual device, because this determines:
- if the guest or the hypervisor must include a device driver
- if the qvm hosting a guest must include the relevant vdev
- if the guest needs to know that it is running in a virtualized environment
In a non-virtualized system, the device driver in an OS must match the hardware device on the physical board. In a virtualized system, the device driver in the guest must match the vdev.
For example, suppose you are using a vdev-pl011 vdev configured
as follows: vdev vdev-pl011 loc 0x1c090000 intr gic:37.
You must then tell your guest to use a PL011 device at location
0x1c090000 and interrupt 37.
You can't pass instructions to your guest to use a UART device, say
earlycon=msm_hsl_uart,0x75b0000, and expect it to find the
PL011 device any more than you could do that in a non-virtualized environment.
For information about configuring the hypervisor host, qvm
processes, and devices, see the Configuration
chapter.