Best way to shutdown VM?

[kanav99]

I am writing a wrapper over xhyve in swift, where I have given setuid to the xhyve binary (!!) and run the Ubuntu VM on a button click. Now I want to shut down the VM. Options -

1. Make a root user and set its ssh shell to poweroff. But this can be exploited by any other applications.
2. Run kill - nope, because I don't want to give setuid to a binary that can kill
3. SIGINT - Not graceful
4. Simulating Ctrl + SysRq + o - how do I do this?

I want to do a safe shutdown - what should be the best way?

[TimDaub]

I'm also wondering how to do this. I usually use halt when I was successful in booting the machine. But for machines that are broken, I always have to shut down the process manually somehow.

[jacobvosmaer]

Inside a VM I use halt. Outside the VM, you can use SIGTERM. That gets translated into a "power button" press, and that typically triggers an OS shutdown.

xhyve/src/pm.c

Line 273 in 83516a0

power_button = mevent_add(SIGTERM, EVF_SIGNAL,

Note that if the xhyve process runs as root, you need to also send SIGTERM as root.