If you are looking for the QEMU Guest Agent protocol reference, see:

/usr/share/doc/packages/qemu/interop/qemu-ga-ref.html

The file you are reading is now provided simply to support a packaging

"Split-Provides", in order to maintain prior-release functionality. The

new package has split that functionality into another package which may

be optional going forward. If you find the package providing this file

is not needed, you may uninstall it.