    /*
     * 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) IBM Corp. 2006
     */

    #ifndef _XEN_XENCOMM_H_
    #define _XEN_XENCOMM_H_

    /* A xencomm descriptor is a scatter/gather list containing physical
     * addresses corresponding to a virtually contiguous memory area. The
     * hypervisor translates these physical addresses to machine addresses to copy
     * to and from the virtually contiguous area.
     */

    #define XENCOMM_MAGIC 0x58434F4D /* 'XCOM' */
    #define XENCOMM_INVALID (~0UL)

    struct xencomm_desc {
        uint32_t magic;
        uint32_t nr_addrs; /* the number of entries in address[] */
        uint64_t address[0];
    };

    #endif /* _XEN_XENCOMM_H_ */