    /*
     * hvm/save.h
     *
     * Structure definitions for HVM state that is held by Xen and must
     * be saved along with the domain's memory and device-model state.
     *
     * Copyright (c) 2007 XenSource Ltd.
     *
     * 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.
     */

    #ifndef __XEN_PUBLIC_HVM_SAVE_H__
    #define __XEN_PUBLIC_HVM_SAVE_H__

    /*
     * Structures in this header *must* have the same layout in 32bit
     * and 64bit environments: this means that all fields must be explicitly
     * sized types and aligned to their sizes, and the structs must be
     * a multiple of eight bytes long.
     *
     * Only the state necessary for saving and restoring (i.e. fields
     * that are analogous to actual hardware state) should go in this file.
     * Internal mechanisms should be kept in Xen-private headers.
     */

    #if !defined(__GNUC__) || defined(__STRICT_ANSI__)
    #error "Anonymous structs/unions are a GNU extension."
    #endif

    /*
     * Each entry is preceded by a descriptor giving its type and length
     */
    struct hvm_save_descriptor {
        uint16_t typecode;          /* Used to demux the various types below */
        uint16_t instance;          /* Further demux within a type */
        uint32_t length;            /* In bytes, *not* including this descriptor */
    };

    /*
     * Each entry has a datatype associated with it: for example, the CPU state
     * is saved as a HVM_SAVE_TYPE(CPU), which has HVM_SAVE_LENGTH(CPU),
     * and is identified by a descriptor with typecode HVM_SAVE_CODE(CPU).
     * DECLARE_HVM_SAVE_TYPE binds these things together with some type-system
     * ugliness.
     */

    #ifdef __XEN__
    # define DECLARE_HVM_SAVE_TYPE_COMPAT(_x, _code, _type, _ctype, _fix)     \
        static inline int __HVM_SAVE_FIX_COMPAT_##_x(void *h, uint32_t size)  \
            { return _fix(h, size); }                                         \
        struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[2];};  \
        struct __HVM_SAVE_TYPE_COMPAT_##_x { _ctype t; }

    # include <xen/lib.h> /* BUG() */
    # define DECLARE_HVM_SAVE_TYPE(_x, _code, _type)                         \
        static inline int __HVM_SAVE_FIX_COMPAT_##_x(void *h, uint32_t size) \
            { BUG(); return -1; }                                            \
        struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[1];}; \
        struct __HVM_SAVE_TYPE_COMPAT_##_x { _type t; }
    #else
    # define DECLARE_HVM_SAVE_TYPE_COMPAT(_x, _code, _type, _ctype, _fix)     \
        struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[2];}

    # define DECLARE_HVM_SAVE_TYPE(_x, _code, _type)                         \
        struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[1];}
    #endif

    #define HVM_SAVE_TYPE(_x) __typeof__ (((struct __HVM_SAVE_TYPE_##_x *)(0))->t)
    #define HVM_SAVE_LENGTH(_x) (sizeof (HVM_SAVE_TYPE(_x)))
    #define HVM_SAVE_CODE(_x) (sizeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->c))

    #ifdef __XEN__
    # define HVM_SAVE_TYPE_COMPAT(_x) __typeof__ (((struct __HVM_SAVE_TYPE_COMPAT_##_x *)(0))->t)
    # define HVM_SAVE_LENGTH_COMPAT(_x) (sizeof (HVM_SAVE_TYPE_COMPAT(_x)))

    # define HVM_SAVE_HAS_COMPAT(_x) (sizeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->cpt)-1)
    # define HVM_SAVE_FIX_COMPAT(_x, _dst, _size) __HVM_SAVE_FIX_COMPAT_##_x(_dst, _size)
    #endif

    /*
     * The series of save records is teminated by a zero-type, zero-length
     * descriptor.
     */

    struct hvm_save_end {};
    DECLARE_HVM_SAVE_TYPE(END, 0, struct hvm_save_end);

    #if defined(__i386__) || defined(__x86_64__)
    #include "../arch-x86/hvm/save.h"
    #elif defined(__arm__) || defined(__aarch64__)
    #include "../arch-arm/hvm/save.h"
    #else
    #error "unsupported architecture"
    #endif

    #endif /* __XEN_PUBLIC_HVM_SAVE_H__ */