Nesting Hyper-v 2012 in Esxi5.1

Hi.

I'm trying to create a couple of Windows 2012 VM with Hyper-v enabled to set up a LAB.

I've added the vhv.allow TRUE entry to the /etc/vmware/config file ( though I did not reboot the server )

I've added the hypervisor.cpuid.v0 false on the vm configuration .

But still when I try to enable the Hyper-v feature it fails stating the the "server" has not the necessary virtualization capabilities .

Anyone can help me finding what I'm missing ?

thanks