I recently created a sys-usb vm and was locked out of my system. Thankfully, I had a PS/2 keyboard nearby and used that to regain access to my system. I was really tired and it was a dumb mistake. I have only been using Qubes for about 2 months and this is my second Linux distribution.
When I chose to create the sys-usb, I used the command
sudo qubesctl state.sls qvm.usb-keyboard
to automatically install and configure the keyboard. In panic and realizing I was about to disable my USB keyboard/mouse, I closed the dom0 terminal before the command was done executing.
The sys-usb vm was created still, and I was locked out. When I logged back in using the PS/2 keyboard, I used ALT + F1 to find and open Qubes Manager along with the dom0 XFCE terminal. I had no mouse access, so figuring out how to do this all with only a keyboard was a stressful challenge.
On a separate device, I visited the documentation for removing a USB qube…
Removing a USB qube
Warning: This procedure will result in your USB controller(s) being attached directly to dom0.
GRUB2
Shut down the USB qube.
In Qubes Manager, right-click on the USB qube and select “Remove VM.”
Open the file /etc/default/grub
in dom0.
Find the line(s) that begins with GRUB_CMDLINE_LINUX
.
If rd.qubes.hide_all_usb
appears anywhere in those lines, remove it.
Save and close the file.
Run the command grub2-mkconfig -o /boot/grub2/grub.cfg
in dom0.
Reboot.
So, steps one and two went fine, I deleted the USB qube.
Except, when I opened the file /etc/default/grub in dom0, in step 3, the line rd.qubes.hide_all_usb was not present at all. I proceeded to run the command grub2-mkconfig -o /boot/grub2/grub.cfg in dom0, but the console told me I needed root privileges. I decided to stop here and did NOT run this command, because I did not want to cause anything else to happen.
I used the commands
nano /etc/qubes-rpc/policy/qubes.InputKeyboard
and
nano /etc/qubes-rpc/policy/qubes.InputMouse
to investigate the policy files in dom0. When I opened them, they were completely empty, nothing. This leads me to believe that because I exited the automatic setup of sys-usb, that there was some errors that took place.
The only thing I had really changed at that point, was deleted the sys-usb Qube, which apparently worked for me, because when I restarted, my USB keyboard and mouse were active again at login.
HOWEVER…
My background is now grayed out, I cannot see desktop icons, and if I right click the desktop, no menu appears. I cannot set a background either even though under the desktop customization menu, I have all the wallpapers preloaded with Qubes still present and changing in between wallpapers does not do anything. The background still stays grey.
Please help me fix this issue or forward my post to someone who might know how to help me! I am currently backing up all my important files onto a USB to prevent any loss of data if anything like this mishap happens again.