GPU Passthrough + noVNC

[dcrdev]

I’ve been using GPU passthrough with my Windows VMs for some time and have largely accepted that doing so means the noVNC console in Proxmox is unusable. The problem is that on a couple of occasions Windows Update has failed, leaving me completely blind as to what’s actually happening.

Is there any way to make this workable?

If I re-add the default display and keep the passthrough GPU as a secondary device, Windows simply refuses to use the passthrough GPU for acceleration.

The passthrough GPU itself is an SR-IOV device, so attaching a physical display isn’t an option. I mainly rely on RDP and Parsec, but neither works pre-boot or during Windows updates, which is where I get stuck.

 

[leesteken]

Maybe you can add a (virtual) serial console to your Windows VM? I have no experience with this but it looks like you can configure Windows to (also) use a serial console.

 

[dcsapak]

Is there any way to make this workable?

sadly, not really

to access the display of a vm via vnc, qemu has to have access to that. and that only works for the built in (virtual) gpus and some select vgpus (e.g. nvidia vgpu). But even there we don't utilize this, since in our testing it was a bit unstable so we didn't implement it (we would have to add 'display=on' to the vgpu device for qemu)

for "generic" pci passthrough (and sr-iov in your case), there is no way to access the framebuffer of the device from the qemu side, so the only solution is to use some kind of remote desktop from inside.

but if you use a virtual gpu, using remote desktop should still let you use the 'real' card, e.g. i do this here to test with an intel b50 pro + sriov + windows remote desktop