Linux Kernel Module Cheat

The QEMU monitor is a magic terminal that allows you to send text commands to the QEMU VM itself: https://en.wikibooks.org/wiki/QEMU/Monitor

While QEMU is running, on another terminal, run:

or send one command such as info qtree and quit the monitor:

or equivalently:

Source: qemu-monitor

qemu-monitor uses the -monitor QEMU command line option, which makes the monitor listen from a socket.

Alternatively, we can also enter the QEMU monitor from inside -nographics QEMU text mode with:

and go back to the terminal with:

When in graphic mode, we can do it from the GUI:

where ? is a digit 1, or 2, or, 3, etc. depending on what else is available on the GUI: serial, parallel and frame buffer.

Finally, we can also access QEMU monitor commands directly from GDB step debug with the monitor command:

then inside that shell:

This way you can use both QEMU monitor and GDB commands to inspect the guest from inside a single shell! Pretty awesome.

In general, ./qemu-monitor is the best option, as it:

Getting everything to work required careful choice of QEMU command line options: