This hasn’t happened to me yet but I was just thinking about it. Let’s say you have a server with an iGPU, and you use GPU passthrough to let VMs use the iGPU. And then one day the host’s ssh server breaks, maybe you did something stupid or there was a bad update. Are you fucked? How could you possibly recover, with no display and no SSH? The only thing I can think of is setting up serial access for emergencies like this, but I rarely hear about serial access nowadays so I wonder if there’s some other solution here.
For very simple tasks you can usually blindly log in and run commands. I’ve done this with very simple tasks, e.g., rebooting or bringing up a network interface. It’s maybe not the smartest, but basically, just type root, the root password, and dhclient eth0 or whatever magic you need. No display required, unless you make a typo…
In your specific case, you could have a shell script that stops VMs and disables passthrough, so you just log in and invoke that script. Bonus points if you create a dedicated user with that script set as their shell (or just put in the appropriate dot rc file).
