Sometimes you might want to run a hypervisor on a hypervisor for testing purposes…. this is how you pass through the required CPU extensions in ESXi 5.1
Remember you will also need to enable promiscuous mode on the networking side also.
http://www.virtuallyghetto.com/2012/08/how-to-enable-nested-esxi-other.html
There are some changes with Nested Virtualization in vSphere 5.1 also officially known as VHV (Virtual Hardware-Assisted Virtualization). If you are using vSphere 5.0 to run Nested ESXi or other nested Hypervisors, then please take a look at the instructions in this article. With vSphere 5.1, there have been a few minor changes to enable VHV.
- The new Virtual Hardware 9 compatibility will be required when creating your nested ESXi VM, Virtual Hardware 8 will not work if you are running ESXi 5.1 on your physical host. You will still need to enable promiscuous mode on the portgroup that will be used for your nested ESXi VM for network connectivity.
- vhv.allow = “true” is no longer valid for ESXi 5.1 to enable VHV. A new parameter has been introduced called vhv.enable = “true” that is now defined on a per VM basis to provide finer granularity of VHV support. This also allows for better portability between VMware’s hosted products such as VMware Fusion and Workstation as they also support the vhv.enable parameter.
- You can now enable VHV on a per VM basis and using the new vSphere Web Client which basically adds the vhv.enable = “true” parameter to the VM’s .VMX configuration file.