Thanks! I was not aware of libvirt/libvirt_qemu can directly invoke qmp commands. From libvirt Python code, there are some APIs missing, e.g., guest-exec().
"There's some synchronization needed first to reset agent's internal state: https://gitlab.com/libvirt/libvirt/-/blob/master/src/qemu/qemu_agent.c?re..." As for guest synchronization, is there something need to to manually for synchronization? Regards