Description of problem:
Input some commands in QMP and then check the history used commands by the following command, the used commands can not be returned:
{"execute":"human-monitor-command","arguments":{"command-line":"info history"}}

Version-Release number of selected component (if applicable):
kernel-2.6.32-171.el6.x86_64
qemu-kvm-0.12.1.2-2.172.el6.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Start a guest with QMP.
/usr/libexec/qemu-kvm -m 8G -smp 4 -cpu cpu64-rhel6,+x2apic -usbdevice tablet -drive file=RHEL-Server-6.1-64-virtio.qcow2,format=qcow2,if=none,id=drive-ide0-0-0,werror=stop,rerror=stop,cache=none -device virtio-blk-pci,drive=drive-ide0-0-0,id=ide0-0-0 -netdev tap,id=hostnet0,script=/etc/qemu-ifup -device e1000,netdev=hostnet0,mac=00:10:1a:20:06:28,bus=pci.0,addr=0x6 -boot c -uuid bea9c85e-0a47-4030-979d-5d94bb3d6161 -rtc-td-hack -no-kvm-pit-reinjection -monitor stdio -qmp tcp:0:4444,server,nowait -name win7-64-balloon -vnc :10 -device virtio-balloon-pci,bus=pci.0,id=balloon0

2.Input some QMP commands 

{"execute":"qmp_capabilities"}
{"return": {}}
{"execute":"query-status"}
{"return": {"singlestep": false, "running": true}}
{"execute":"query-kvm"}
{"return": {"enabled": true, "present": true}}

3.Check the historical used commands:
{"execute":"human-monitor-command","arguments":{"command-line":"info history"}}
{"return": {}}

  
Actual results:
The used command like "query-status" and "query-kvm" do not return.

Expected results:
Should display history commands after step3.

Additional info: