Supernested is a test of nested KVM.  It is able to run KVM, nested to
any depth, limited only by available memory, bugs in KVM, and your
patience.


Author
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By Richard W.M. Jones <rjones@redhat.com>

Bugs, feedback etc: http://www.redhat.com/mailman/listinfo/virt-tools-list

(Note: Bugs in KVM or the kernel should be reported to the qemu-devel
or Linux kernel mailing lists respectively)


License
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Gnu General Public License, version 2 or above.  See 'COPYING'.


Requirements
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 - supermin version 5
   https://github.com/libguestfs/supermin
   Note: older versions of supermin will not work

 - guestfish

 - recent qemu and kernel

 - qemu-img

 - getopt(1) utility (from util-linux)

 - Only tested on Fedora, but it should work on other Linux distros
   *provided* they have supermin 5 support.  Patches to fix that are
   welcome.


Compiling the disk image
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To build the disk image, do:

  autoreconf -i
  ./configure
  make

Assuming that works you will end up with 4 files:

 - 'supernested-<VERSION>-<DISTRO>.qcow2'
   The disk image.

 - 'kernel'

 - 'initrd'

 - 'run-supernested.sh'

You need all 4 files for the next step.


Running the disk image
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!NOTE FIRST!  If nested KVM is broken, it can *frequently* cause your
host machine to crash, reboot, catch fire, etc.  You need to run this
on baremetal, on a machine which is KVM-capable, a modern CPU, with
lots of free memory, and nothing much else running.

You need to have the kernel KVM module (eg. kvm_amd or kvm_intel)
loaded, with the nested flag set.  The nested flag defaults to true in
recent kernels.  /dev/kvm needs to be accessible.  On some distros
you may need to add your user to a special 'kvm' group.

You *don't* need to run this command as root.  Running it as root may
give different results.  Consult a qemu/KVM expert.

Have a look at the 'run-supernested.sh' script.  You may want to edit
things like the name of the qemu binary.

  ./run-supernested.sh