    /******************************************************************************
     * xen-compat.h
     *
     * Guest OS interface to Xen.  Compatibility layer.
     *
     * Permission is hereby granted, free of charge, to any person obtaining a copy
     * of this software and associated documentation files (the "Software"), to
     * deal in the Software without restriction, including without limitation the
     * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     * sell copies of the Software, and to permit persons to whom the Software is
     * furnished to do so, subject to the following conditions:
     *
     * The above copyright notice and this permission notice shall be included in
     * all copies or substantial portions of the Software.
     *
     * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     * DEALINGS IN THE SOFTWARE.
     *
     * Copyright (c) 2006, Christian Limpach
     */

    #ifndef __XEN_PUBLIC_XEN_COMPAT_H__
    #define __XEN_PUBLIC_XEN_COMPAT_H__

    #define __XEN_LATEST_INTERFACE_VERSION__ 0x00040900

    #if defined(__XEN__) || defined(__XEN_TOOLS__)
    /* Xen is built with matching headers and implements the latest interface. */
    #define __XEN_INTERFACE_VERSION__ __XEN_LATEST_INTERFACE_VERSION__
    #elif !defined(__XEN_INTERFACE_VERSION__)
    /* Guests which do not specify a version get the legacy interface. */
    #define __XEN_INTERFACE_VERSION__ 0x00000000
    #endif

    #if __XEN_INTERFACE_VERSION__ > __XEN_LATEST_INTERFACE_VERSION__
    #error "These header files do not support the requested interface version."
    #endif

    #endif /* __XEN_PUBLIC_XEN_COMPAT_H__ */