It would be useless and I will say why
1) People who run Linux almost never run Linux in a VM, so Phoronix Test Suit is not suitable here.
2) VM differ so much, you'd better choose 'em based on their features and price, rather than performance.
* VirtualBox is free but not very stable.
* VMWare WorkStation costs money but it's absolutely rock solid and allows Aero effects for Windows Vista/7.
* QEMU is not very usable for usual users.
3) There are billions of different workloads you may have in your VM, it's impossible to test even 1% of them.
4) There are tens of Operation Systems you may run.