Virtualization – Enable Nested Virtualization in Ubuntu

virtualboxvirtualization

I would like to do some lib testing on my OS. So I need several environment to run KVM. And I found my guest machine was not able to run KVM.

I was using virtualbox 4.2.

Best Answer

KVM requires VT-X/AMD-V, but VirtualBox does not pass VT-X/AMD-V to the guest operating system.

Therefore, KVM can't run in VirtualBox (yet). Please track bug ticket #4032.

VT-X and AMD-V (so-called virtualization extensions) run the guest operating system natively in the CPU. Without them, the virtualization software must interpret the operating system opcodes in software, which is very slow.

For now, you can either

run KVM inside a hypervisor which passes virtualization extensions to the guest (e.g. KVM inside VMware Workstation 8), or
run another hypervisor inside VirtualBox (e.g. VirtualBox inside VirtualBox). This option will be very slow, because the guest will miss VT-X/AMD-V.

Related Solutions

Ubuntu – Virtualization of Windows on Ubuntu 11.10 64 bit

At least for the time being, Virtualbox is the best solution to virtualize Windows desktops. It has support for 3D and 2D acceleration which improves the user experience. It also has easy support for USB. I also think the configuration GUI is a little bit more user friendly than virt-manager, though that's a nice GUI as well.

I've been told that we'll get SPICE in 12.04, and that may change things, but for now, go with Virtualbox.

Ubuntu – Extra mouse buttons not working in virtualization (VMware/VirtualBox, ubuntu host)

Possible workaround:

After editing the VM's .vmx file to add

mouse.vusb.enable = "TRUE"
mouse.vusb.useBasicMouse = "FALSE"
usb.generic.allowHID = "TRUE"

you'll be able to use your five-button mouse in the VM. To do so, open your VM, then navigate to Virtual Machine > Removable Devices > [Your Mouse] > Connect (Disconnect from Host). You'll get a couple warnings that you won't be able to use your mouse with the host anymore, and just click OK.

Now you can only use your mouse within the VM whether it's full-screen or in windowed mode. Hit Ctrl-G on your keyboard to get rid of the host mouse icon and fully immerse yourself in the VM. Once you need your mouse again outside the VM, hit Ctrl+Alt, then release. Now the focus is back to your host OS. Hold Alt and push V to bring up the Virtual Machine menu, and use your arrow keys to navigate to Virtual Machine > Removable Devices > [Your Mouse] > Disconnect (Connect to Host).

Now everything is back to normal. Hopefully something will change in either Ubuntu or VMWare Player soon to make it easier than this.

Best Answer

Related Solutions

Ubuntu – Virtualization of Windows on Ubuntu 11.10 64 bit

Ubuntu – Extra mouse buttons not working in virtualization (VMware/VirtualBox, ubuntu host)

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