Thin provisioning physical layer vs VHDX

So I'm creating a new host with Server 2012 core and I'm going to run server 2012 essentials on a VM.  I'm trying to decide what to do with the disks.

I have created a 2TB volume on the physical layer that is thin provisioned using storage spaces and would like to create a 1.5TB vhd for essentials main disk but if I create this as a fixed volume then will it use the full 1.5TB of the physical volume?  If so, what's the point of thin provisioning at the physical layer for virtualized workloads?

If I used thin provisoning at the virtual layer then do I pay a performance penalty twice?  Once with the VHDX file and then again at the physical layer?

Any recommendations on how to set this up so I make the most efficient use of disk space here?