kvm-kmod Quickstart
-------------------

./configure
make
make install


Build Details
-------------

Building the KVM kernel module is performed differently depending on whether
you are working from a clone of the git repository or from a source release.
Notice that two kernels are involved: One from which the KVM sources
are taken (kernel A), and one for which the module is built (kernel B).
In almost all cases, kernel A is more recent than kernel B.

- To build from a release (this is the default case), simply
  use ./configure (possibly with any arguments that are required for
  your setup, see ./configure --help) and make. The kernel specified
  with --kerneldir refers to kernel B, that is, the kernel for which
  the module is built. All sources required from kernel A are already
  included in the release.

- Building from a cloned git repository (most likely useful for developers
  only) requires a kernel tree with the main kvm sources (kernel A) that
  is included as a submodule in the linux/ directory.  By default, the KVM
  development tree on git.kernel.org is used, but this can be changed in
  the git configuration after the 'submodule init' step.

  Before the kvm module can be built, the linux submodule must be initialised
  and populated. The required sequence of commands is

  git submodule init
  git submodule update
  ./configure
  make sync
  make

  Notice that you can also specify an existing Linux tree for the
  synchronisation stage by using

  make sync LINUX=/path/to/kernel/A

  LINUX specifies the path to kernel A from which the KVM sources are taken.
  The directory must point to a local git tree, not to a plain directory
  containing the kernel sources. If LINUX is unset, the default value is
  linux/, i.e., the git submodule.

  Note that configure may refuse to build against your target kernel if it
  considers it too new or too old. If you know what you are doing, you can
  override this check by passing --force.