VMware does not support nested ESXi guest is a matter of policy; not a matter of technological possibility. You can run an ESXi within an ESXi as VM.

vhv.enabled = "true" set the vmx configuration file of an ESXi will allow the ESXi VM to support virtualisation within it.

If you haven't seen/read this Running Nested VMs , you should read that.

Hello,

You are correct, VMware will not support Nested ESXi.  The meaning of "vhv.enabled = true"

Nested virtualization is when you run guest hypervisor, like ESXi 5 or later version, inside a virtual machine(VM) instead that on real physical server hardware. This will require hardware-assisted virtualization (HV) for 64-bit capable system and CPU. Because of the we enabling vhv.enabled = true.  Refer the below

http://www.virtuallyghetto.com/2011/07/how-to-enable-support-for-nested-64bit.html   ..

Hello,

Guests on the ESXi guest  | <-- Unsupported. -- > Means Installing ESXi on vmware workstation/fusion for home testing purpose. You are not supported

type1 hypervisor[Nested ESXi] | <-- Unsupported. --> Install ESXi inside an ESXi, then install & configure VMs on that inside ESXi hosts, not supported.

type1 hypervisor[ESXi host]    | --> Yes. You are supported. If your are installing licensed ESXi on recommended Hardware. Refer recommended h/w list,

VMware Compatibility Guide - System Search