Vm share device memory ( ivshmem )

Hello, friends.
I encounter a problem when i use ivshmem with my guest, my ivshmem server is not start, and output a error : Example code, do not use in production ,cannot bind.

Detail distribution:
Today, I know ivshmem from a topic “QEMU version 2.10.93 User Documentation”,
Ivshmem: it can create a shared memory that guest device use, so we can use this memory to do something ourselves.
First, I create host memory backend:
-object memory-backend-file,size=1M,share,mem-path=/dev/shm/ivshmem,id=hostmem
Twice, Bind a shared memory device to my guest:
-device ivshmem-plain,memdev=hostmem
Then I boot ivshmem servi
ivshmem-server -p /var/run/ivshmem-server.pid -S /tmp/ivshmem_socket -M ivshmem -m /dev/shm -l 1M -n 2
Next time i get this error:
*** Example code, do not use in production ***
cannot bind
And i search the problem on google, but nothing to get, hope you can help me solve it.
following message is my host environment:
host: ubuntu 1604
qemu: version 2.10.90 (v2.11.0-rc0-dirty)
libvirt: libvirtd (libvirt) 3.9.0
guest: window 7 professor

Refer:
https://qemu.weilnetz.de/doc/qemu-doc.html#Inter_002dVM-Shared-Memory-device (topic qemu documention)
https://helpmanual.io/help/ivshmem-server/ ( how to use ivshmem-server )