Passing through USB device(s) causes linux VM not to boot.

[wheeliebinladin]

Hi to all.

This is my first thread and i am relatively new (3 months) into using Proxmox.
I have just upgraded to PVE 8.2.4 which i understand to be the latest version, however my problem existed before the upgrade.

My hardware is a Dell Optiplex 7070 I7-9700 with 32gb of ram
Nvme boot drive and 2 backup rust drives (1 sata 1 usb)

I have successfully passed through the IGPU (Intel UHD630) to the Debian12 VM i am having the issue with.
The VM starts and runs normally with no usb devices passed through and i can then add them (USB keyboard, mouse and sound usually) i mostly use mapped devices although have tried the other ways.
With the keyboard and mouse passed through before starting the VM it does not boot or display anything on the passed through GPU.

This is not the case in Windows VMs, and it seems to work fine with my Home Assistant VM also, though i would need to double check that as i don't currently passthrough any devices there.

It leads me to wonder if it is something to do with the IGPU passthrough, although i feel in over my head.

While i am a newbie to Proxmox, I am enjoying the ride so far and hoping someone can point me in the right direction to diagnosing this issue. Apologies for the lack of included information but i am more than happy to share whatever information anyone may require if you tell me what and how

Thanks for reading - Joe

 

[bkinigadner]

I can replicate the problem with just a keyboard, so it's not the iGPUs fault.
Do you see something on the noVNC console in the proxmox web interface

 

[wheeliebinladin]

I do recall the console coming up and failing to even locate a boot device if i remember rightly, I'm on the machine just now so I'll go ahead and reboot it without removing the usb keyboard and mouse, monitoring what is on the console, will grab a screenshot

 

[wheeliebinladin]

So its not frozen, flashing cursor but will not move from there. Workaround has been just to remove the USB keyboard and mouse, start it up then add them after the VM is running. This is a pain though as it means i need another device rather than have that happen on boot.

ii proxmox-kernel-6.5.13-5-pve-signed 6.5.13-5 amd64 Proxmox Kernel Image (signed)
ii proxmox-kernel-6.8.4-2-pve-signed 6.8.4-2 amd64 Proxmox Kernel Image (signed)
ii proxmox-kernel-6.8.4-3-pve-signed 6.8.4-3 amd64 Proxmox Kernel Image (signed)
ii proxmox-kernel-6.8.8-2-pve-signed 6.8.8-2 amd64 Proxmox Kernel Image (signed)

also just switched to an older kernel shown above while trying to get an output in windows on the igpu (seperate issue)
the problem exists on all above kernels for me if that helps anyone.

 

[bkinigadner]

The problem on my system was that grup was not working.
Try to boot into the vm using this iso https://sourceforge.net/projects/supergrub2/
You can do this by downloading it to your ISOs, then go to the VM to the Hardware section, add a CD drive and select the new supergrub2. Now reboot the VM and while the proxmox logo is visible press ESCAPE. You should now see a boot menu were you are able to boot into the new supergrub2 iso.
Now try to detect existing OS, with the supergrub and boot debian.

 

[wheeliebinladin]

Thank you! I'll give that a try here in a minute and post back how i get on.

 

[wheeliebinladin]

Downloaded and followed the above instructions. When i remove the USB devices i can follow above and boot into the VM as normal but when i restart with USB devices mapped, its back to the screenshot before, that is before it even gets to the grub screen. So i would guess the problem is before that. Am i missing something maybe. Very much a Proxmox rookie here

 

[bkinigadner]

Could you try a different keyboard

 

[wheeliebinladin]

same result doesnt seem to matter what usb device, (all/any cause the same result)

i also removed the igpu to rule that out too