VMs output to attached Monitor?

[sgtpepperaut]

Is it generally possible to have a Guest VM use a physically attached monitor like its "normal" display?
Is it perhaps even possible that when X Monitors are a connected that X VMs use these external monitors?
i.e.: show each VM on a attached display?

Is a dedicated GPU required?
Does each VM need its own GPU or could Proxmox assign the "multiple" outputs of one GPU to each VM?

Use Case:
I have an CCTV windows setup that needs 2 Monitors to view live images.
I have another OS that displays a dashboard on a single Monitor.

Ideally id like to virtualize both on a single Proxmox Machine


Thanks for any info

 

[r.jochum]

I know its possible to passthrough one GPU for one or more monitors (its in there VM like on a real machine).
I'm not sure thats possible for Monitors, I either think it's not.

Kind regards,
René

 

[aaron]

You will have to pass through a GPU per VM. Especially if you need to use the actual Monitor outputs of the GPU.

Another approach could be to have a small dedicated box to which the monitors are connected and then use a remote desktop solution to show the VMs displays? Could be RDP for Windows VMs and either Spice or the browser based noVNC for the other VM that only needs one monitor.

Either the one GPU in that box can handle 3 monitors or you can add more GPUs or use a GPU which does support a lot of displays. Matrox comes to mind for the latter.

 

[ickam]

You will have to pass through a GPU per VM. Especially if you need to use the actual Monitor outputs of the GPU.

Another approach could be to have a small dedicated box to which the monitors are connected and then use a remote desktop solution to show the VMs displays? Could be RDP for Windows VMs and either Spice or the browser based noVNC for the other VM that only needs one monitor.

Either the one GPU in that box can handle 3 monitors or you can add more GPUs or use a GPU which does support a lot of displays. Matrox comes to mind for the latter.

So I wanted to convert my pc to a proxmox host with my previous windows installation converted to a guest os.
so I have my gpu passedthrough to the VM, and it seems to be working after a fashion, but I don't get hdmi output. Is there any setting that I need to tweak?

 

[mr44er]

Is there any setting that I need to tweak?

Not really, but let's see. Normally you do pci passthrough with your gpu, tick 'primary gpu' and in the moment you start this vm, the monitor connected to that HDMI should flicker up. If it gives directly a picture and you can see windows booting up (turning dots), then your card is new enough to have a UEFI vBIOS and everything is good.
If it is older (+5-8 years) and with a legacy BIOS, the monitor flickers up but stays black until Windows reaches the login screen (no turning dots until).
Sometimes it could be that you need to wait 10-20 minutes, until you see the login screen. Windows is pulling the gpu drivers in the background, you just don't see anything until it's ready. So black screen doesn't automatically mean it's not working.