Qubes restarted to blank screen after hiding GPU

User Support
1

I’ve got a GPU, and a CPU with an integrated graphical processor

I identified my GPU with qvm-pci
I added a new line to my GRUB file, GRUB_CMDLINE_LINUX=" rd.qubes.hide_pci=[what qvm-pci told me]:00.0"
I ran grub2-mkconfig -o /boot/grub2/grub.cfg to regenerate the GRUB

When I restarted my PC, Qubes OS displayed what looked like lines of code, and then I ended up with a blank screen
I turned my machine off, and tried again. Same outcome

I eventually managed to get access to my GRUB via another Linux installation on a different disk, then unhid my GPU, and now Qubes OS is back :relieved:

  1. Is there a way to modify the GRUB file from the GRUB menu? Internet searching yielded nothing, and if something goes wrong in the future, I’d like a better solution than “install another Linux distribution and modify Qubes’ GRUB file from there” :wink:
  2. How can I tell Qubes OS “stop using the GPU, and use the graphics processor in the CPU?”
  3. Y’all are a helpful bunch. Is there some way I can donate to Qubes or somesuch? I’m not the kind of technical that can help otherwise
2

Perhaps an oversimplified answer but next time try hitting esc if you have a blank screen (it’ll toggle between log and luks screen). Sometimes the luks unlock screen is blank but if you hit esc, it’ll show a cli version of the request for luks password. This happens on my desktop if I forget to power on the monitor before turning on desktop (it’ll just show blank screen)

  1. You can hit e at the grub countdown screen to edit the grub (unless your timeout is so fast that it isn’t visible). Then you can edit for real in dom0 after logging in

  2. Sorry don’t know. You could change bios to not switching (use integrated only) but probably need to update grub options too

  3. Donate to Qubes | Qubes OS

3

and it is a desktop, or a Laptop device?

In a desktop you very likely have (multiple) different VGA (HDMI, DP, or whatever) output for dGPU and iGPU, and your display is connected to one of those… might be it is the one you hided?

In a Laptop, the dGPU, and the iGPU might have a single output, and you might not even able to use separately those… it is heavily depends on the actual model.

4

Yep, cable in hidden GPU port. Thanks