virtualbox.org

Hello All,

I am wondering if it's possible to run the Xen hypervisor inside a Linux guest? I know any emulator/virtualizer that doesn't use VT-x/AMD-V should technically run inside VirtualBox. I just don't feel like either uninstalling VirtualBox or dual-booting a second Linux partition to play around with Xen. I believe the newer versions of Xen require a VT-x/AMD-V enabled chip.

A side question is... Can you run VirtualBox inside a VirtualBox guest? With VT-x/AMD-V disabled of course.

Quick answer: don't know, try it.

Longer answer: even a VM platform which doesn't use VT-x may still play tricks with privilege levels (rings) that make it awkward to run inside another VM. Hence VM within a VM is not supported whether or not it uses VT-x.

kveroneau wrote:A side question is... Can you run VirtualBox inside a VirtualBox guest? With VT-x/AMD-V disabled of course.

I just tried the following successfully. VT-x/AMD-V was enabled on both VMs.

• OSX running VirtualBox with
  • WinXP (VT-x/AMD-V) running VirtualBox with
    • WinXP (VT-x/AMD-V)

Your second (nested) virtualizer will not have VT-x/AMD-v support. This means no 64 bit guests in the nest. Also you must have nested page support on the real host.
The real question is not nesting VBox in VBox though it is nesting Xen in VBox which is going to be different, especially if it requires VT-x which it won't see.