From Fedora Project Wiki


Configure an existing VM to allow nested virtualization: running performant VMs inside another VM, with access to the host's virtualization extensions.


Virt capable host, latest Fedora VM and latest Fedora host.

How to test

  1. Check whether your host system supports nested virtualization. For Intel processors, look into /sys/module/kvm_intel/parameters/nested, for AMD processors into /sys/module/kvm_amd/parameters/nested. You should receive 1 or Y, if nested virt is supported, 0 or N otherwise. AMD processors should have it enabled by default, (certain) Intel processors might not. Example:
    $ cat /sys/module/kvm_intel/parameters/nested
  2. If your host system does not have nested virt enabled (most probably just Intel case), try to enable it by booting with kvm-intel.nested=1 argument on the kernel command line and check it again. Now you should be enabled.
  3. Make sure your VM is shut down
  4. Open virt-manager, go to the VM details page for that VM.
  5. Click on the CPU page.
  6. In the CPU model field, type 'host-passthrough', click Apply
  7. Start the VM
  8. Inside the VM, do sudo yum groupinstall virtualization
  9. Verify that the guest has virt correctly setup with: sudo virt-host-validate

Expected Results

  1. No obvious errors occur.
  2. sudo virt-host-validate should return PASS for all checks.