VTX | PeteNetLive

Problem

If you want to enable virtualisation in a VM that is running inside Hyper-V (itself a hypervisor). Then you need to expose the virtualisation elements of the physical hosts processor to the nested VM.

In the case of Intel VMs that’s VTx and EPT. (For Intel based CPUs). Under VMware you would simply enable “Expose hardware assisted virtualisation to the guest OS” But in Hyper-V you do not get that option.

KB ID 0000540

Problem

Seen on VMware Workstation, when attempting to virtualise a product that IS a virtualisation hypervisor (ESX for example).

Error: Virtualized Intel VT-x/EPT is disabled for this ESX VM. You will only be able to run 32-bit nested VMs.

At first I (wrongly) assumed that I needed to enable something in the BIOS on my laptop, and searched though every page to enable some virtualization setting that was turned off. But that’s NOT what it’s telling you. what it is telling you is you are trying to virtualize a virtualization product, so all the clever VT settings from your physical machines CPU will be shown to VMware workstation. But that presents a Virtual CPU to the OS you are installing as a guest (In the case above ESX) and THAT virtual CPU does NOT have Intel- VT-x/EPT enabled.

So a “Nested VM” – is a Guest VM, running Inside a Guest Hypervisor, that’s been virtualized.

Solution

Note: I’m using VMware workstation 8.

1. Right click the VM in question and select “Settings”.

2. Hardware Tab > Processors > Tick the option to enable VT-x/EPT or V/RVI > OK.

3. Restart the guest machine.

Note: You can also do this be editing the machines .vmx file with a text editor and adding the following lines;

[box]

monitor.virtual_mmu = "hardware"

monitor.virtual_exec = "hardware"

vhv.enable = "TRUE"

monitor_control.restrict_backdoor = "true"

[/box]

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Tag Archives: VTX

Hyper-V Enable Nested Virtualisation

Problem

Solution: Enable Nested Virtualisation

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