[Spice-devel] Blank screen on SPICE when using vGPU

[Uri Lublin]

On 4/3/19 7:33 PM, James Freeman wrote:
> Hi all,
> 
> Conscious this might not be a SPICE issue but trying to debug where the 
> issue is right now. I'm working with someone who is using RHV 4.2 with a 
> vGPU configuration. At present we are stuck on a problem whereby the 
> vGPU can be successfully assigned to a given VM (either Windows or 
> Linux) and then the VM booted. However as soon as the closed source 
> nVidia drivers are installed and the VM rebooted, the SPICE display is 
> blank (all black).
> 
> Trying to determine where the issue is - with the Windows VM we have 
> been able to RDP in and see that the nVidia driver was loaded and the 
> nVidia control panel loads - this would seem to indicate the driver is 
> loaded and working. Still running some additional tests on the Linux VM 
> - however we're trying to figure out where the problem lies. Is it 
> possible this is an interaction with SPICE, or is this likely an issue 
> at a lower level? Is there a suggested route to debug this issue?

Hi James,

The VM has 2 GPUs, 1 is QXL(*) + 1 is NVIDIA.
(*) QXL or another emulated device.

SPICE connects to the QXL, but the guest is using NVIDIA
which is why the display is black.

There are 2 things you can try (I'm not sure how well they work):
1. Try to run the VM only with the NVIDIA vGPU (no QXL) and
    make add display=on to qemu-kvm command line mdev-device option.
2. Currently only for Linux -- add a spice.stream virtio-serial port
    and run spice-streaming-agent on the guest.

What OS is running on your host/guest ?
Do you actually use both QXL and NVIDIA ?

Uri.