Bug 1844280

Description of problem:

In RHV 4.3.5+ there was a change of logic on how vGPU works via BZ1723580 and the Documentation does not seem to have been updated.

4.3.4 and lower:  VM runs with both vGPU and a QXL/VGA device, while Spice/VNC console uses the QXL/VGA device and is always available
4.3.5 and higher: VM runs only with vGPU, Spice/VNC console is a blank screen until the VM initializes the display when Xorg/GDM loads.

So previously the user could see from console everything from boot. But now the user can only see an output once Xorg/GDM loads.
And if there is no driver installed, the system does not boot into graphical.target by default or the config is broken then there is no output at all.

As a result:

A) In 4.3.5 and later the user cannot follow the docs in [1], becuse step 2.1 prevents the user from accessing the console in step 2.2.
See first step of 2.2.1:
~~~
Run the virtual machine and connect to it using a serial console, such as SPICE or VNC. 
~~~
This doesn't work, there is no console because the vGPU is not initialized yet, as there is no driver (which step 2.2 would install).

The fix for this would be to invert steps 2.1 and 2.2. Install the nVIDIA drivers and only then add the nVidia vGPU.

Other alternatives:
* "nodisplay" option on the mdev_device. (see BZ1844279)
* virtio-serial console (but what about Windows?)
* other remote console such as RDP...

B) The behaviour that console will only work *after* the vGPU is initialized is not clear or explained in the Docs. In RHEL7 Docs [2] we have it explained:
~~~
Also note that using model type='none' currently makes it impossible to see the boot graphical output until the drivers are initialized. As a result, the first graphical output displayed is the login screen. 
~~~

[1] https://access.redhat.com/documentation/en-us/red_hat_virtualization/4.3/html/setting_up_an_nvidia_gpu_for_a_virtual_machine_in_red_hat_virtualization/assigning_virtual_gpus
[2] https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/virtualization_deployment_and_administration_guide/sect-device-GPU#sect-device-GPU-vGPU