PPC: msgsnd instruction leads to assertion

I tried to send doorbells (using msgsnd) between cores in guest OS. On QEMU v2.9.0 usage of msgsnd instruction leads to error:
ERROR: <...>/qemu-new/translate-common.c:34:tcg_handle_interrupt: assertion failed: (qemu_mutex_iothread_locked())


QEMU v2.8.0 works fine.

QEMU run options: qemu-system-ppc -serial stdio -M ppce500 -cpu e500mc -smp 2 -m 512M -kernel pok.elf

pok.elf attached