Comment 18 for bug 1847361

Hello @louis (or @caribou) good to see you again! :)

I had a quick thought on this; maybe we could add a search path to our qemu, to look not only in the normal /usr/lib/x86_64-linux-gnu/qemu for its modules, but also in /run/qemu/$QEMU_VERSION_STAMP/modules/ (or something similar under /run). Then, qemu startup could simply copy its modules into this dir when any guest starts. If qemu is upgraded, it could fallback to this dir for its modules if the current on-disk modules are the wrong version. The modules in /run would disappear across reboots, so they wouldn't be a permanent leak of disk space.

We could even add a post-uninstall script to the package to check if there are any running qemu instances with version matching the specific package being uninstalled, and remove the /run/qemu/$VERSION dir/modules if nothing is running that would need them.

That approach might even be applicable upstream, though without tie-in to the specific packaging (i.e. rpm, deb, etc...) the /run modules would remain until a reboot.