Make sure you are making changes to the *.in file, then running the git workflow script to do the follow on updates.
I don't see an entry in our change log file. qemu.changes needs to explain this change, including referencing by name any new or removed files, any reference to bug numbers or fate entries, etc. It might be a good idea to have the install line for this rule next to (above) the one we have for kvm, but that's not essential.