No display out from integrated graphics/motherboard after PCIe GPU installed & passed through

[PeriodicExcitement]

Hello the Generous and Learned,

I am very new to Proxmox and all things Linux.

I have made changes (following online guides) to passthrough my discrete GPU to a guest - that works fine.
However, I now get no display OUT from the integrated graphics/motherboard.
Because of this, I now cannot access the host's UEFI/BIOS or console.
Web UI works fine.

When I physically remove the PCIe GPU, I get a display OUT from the motherboard.

Could somebody please assist in diagnosing what I've done wrong? Or, what I need to change to get the host/proxmox to use the integrated graphics itself whilst passing the nVidia through to a guest.

I have a new Proxmox installation (7.2-3) running on the following hardware:
i7 7700k
Z270-HD3P-CF
nVidia 1070

Many thanks.

 

[Neobin]

Afaik many mainboards/UEFIs disable the iGPU per default as soon as an discrete GPU is present.
Search in your UEFI if it has an option to explicitly enable the iGPU (not only "Auto").

 

[leesteken]

If this is the manual, try setting Internal Graphics in Chipset to Enabled (instead of Auto).

 

[PeriodicExcitement]

That has fixed the problem of the mobo not giving any display out, thank you.

Unfortunately, passthrough stopped working for my guest.

I've recreated the guest and things are now working perfectly; host console access via mobo display and GPU passthrough working for guest.

Again, thank you.

 

[leesteken]

That has fixed the problem of the mobo not giving any display out, thank you.
Unfortunately, passthrough stopped working for my guest.

Probably several PCI(e) devices shifted their PCI-ID by plus one because the onboard graphics was inserted somewhere in the lower numbers like 00:02.0. This also happens on network devices (whose name depends on the PCI-ID) then a new PCIe device, such as a GPU, is added, which breaks the web GUI and SSH.