Virtfs (Plan 9) vs NFS as tool for share folder for virtual machine

I have QEMU virtual machine. Linux host and linux guest. I want stable and fast solution with minimal performance cost. I'm considering two technologies for shared folders (between guest and host): NFS and VirtFS (Plan 9 ). There is small amount information on VirtFS from one side and there are some evidences that NFS isn't good option for virtualization from another side. So my questions are following. What is more reasonable for my purpose? What is more effective? What solution is consume less (speaking about CPU)? What solution is more fast? Are there some benchmarks on subject?