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王子1986
Asked: 2013-08-05 18:22:11 +0800 CST

How to enable nested virtualization in ubuntu

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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.

virtualbox

3 Answers

  1. 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.
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  2. Virtualbox just released (12/18/2018) version 6 in which is expected to have nested virtualization. However, at this moment it seems is still unavailable on Intel procs. https://www.virtualbox.org/wiki/Downloads

    Regarding the main question (Enable nested virtualization in Ubuntu) - KVM module is supporting nested virtualization on Ubuntu 16 and above (maybe lower versions too). Not sure about using XEN on host, but you can nest XEN in KVM for sure.

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  3. Enable nested virtualization in KVM in UBUNTU Before enabling nested VT feature, power off all running VMs.

    Next, unload KVM modules.

    To unload KVM module on INTEL systems, run:

    $ sudo modprobe -r kvm_intel

    On AMD systems:

    $ sudo modprobe -r kvm_amd

    Reload the KVM module with the nested feature enabled on INTEL CPUs with command:

    $ sudo modprobe kvm_intel nested=1

    Reload the KVM module with the nested feature enabled on AMD CPUs using command:

    $ sudo modprobe kvm_amd nested=1

    Enable nested virtualization permanently according with:

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