I believe we are running into a possible bug with the GTX 1080 (driver) and PCI Passthrough.
My host is an Ubuntu 14.04 system. My guest is an Ubuntu 14.04/16.04 system (both do the same thing).
I can see device inside the guest VM:
$ lspci -vnn | grep VGA 00:05.0 VGA compatible controller: NVIDIA Corporation Device 1b80 (rev a1)
I was able to successfully install the driver (370.2, latest driver). It installs, but is not recognized by
$ nvidia-smi Unable to determine the device handle for GPU 0000:00:05.0: Unknown Error
dmesg I see the following error message
[29.535583] nvidia 0000:00:05.0: irq 45 for MSI/MSI-X [29.577727] NVRM: RmInitAdapter failed! (0x23:0x56:458) [29.577807] NVRM: rm_init_adapter failed for device bearing minor number 0
I can switch out the GTX 1080 for a different card (M4000, do passthrough and install drivers on guest) and it works. I am going to try tomorrow with another Geforce card.
Another person on the NVidia forums had the SAME exact issue as me (but no answer).
Is there anyway to debug this further?