It succeeds to load with LD_PRELOAD as, as I understand, block_register() gets called.
QAPI and new QAPI-based block device syntax don't work though because they're
based on IDLs built into QEMU... QAPI will require patching, yeah. It would be nicer if
QAPI supported plugins too... :-)
--
With best regards,
Vitaliy Filippov