[libvirt] How about realize domainSetBlockIoTune by cgroup?

Hello experts, It seems that blkiotune of kvm domain is set through qemu now, and We found there are some throttle shaking problem when using this interface. As you can do the same thing through blkio cgroup, and this sounds to show better performance, Can we realize domainSetBlockIoTune by cgroup just like interface domainSetBlkioParameters ? Or Add a new interface to support setting disk IOtune by blkio cgroup? Thanks ------------------ Best regards! GuanQiang 2013-08-27