def METHOD_NAME():
    """
    Return a list of all installed kernels.
    CLI Example:
    .. code-block:: bash
        salt '*' kernelpkg.list_installed
    """
    pkg_re = re.compile(r"^{}-[\d.-]+-{}$".format(_package_prefix(), _kernel_type()))
    pkgs = __salt__["pkg.list_pkgs"](versions_as_list=True)
    if pkgs is None:
        pkgs = []
    result = list(filter(pkg_re.match, pkgs))
    if result is None:
        return []
    prefix_len = len(_package_prefix()) + 1
    return sorted(
        (pkg[prefix_len:] for pkg in result), key=functools.cmp_to_key(_cmp_version)
    )