[Qemu-discuss] how to list sub-options in QMP like "?" in qemu monitor windows

[TianXu]

Hello list,

I have a tiny question about QMP, hope to get answer from mail list. As I know, 
in qemu monitor window "?" is a very useful command to list supported 
sub-option, ( "pci_add ?" to list which kind of PCI device can be add) My 
question is that any command can do the same thing in QMP?

Thanks,
Xu