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      1 /*
      2  * hvm/save.h
      3  *
      4  * Structure definitions for HVM state that is held by Xen and must
      5  * be saved along with the domain's memory and device-model state.
      6  *
      7  * Copyright (c) 2007 XenSource Ltd.
      8  *
      9  * Permission is hereby granted, free of charge, to any person obtaining a copy
     10  * of this software and associated documentation files (the "Software"), to
     11  * deal in the Software without restriction, including without limitation the
     12  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
     13  * sell copies of the Software, and to permit persons to whom the Software is
     14  * furnished to do so, subject to the following conditions:
     15  *
     16  * The above copyright notice and this permission notice shall be included in
     17  * all copies or substantial portions of the Software.
     18  *
     19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     22  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     25  * DEALINGS IN THE SOFTWARE.
     26  */
     27 
     28 #ifndef __XEN_PUBLIC_HVM_SAVE_H__
     29 #define __XEN_PUBLIC_HVM_SAVE_H__
     30 
     31 /*
     32  * Structures in this header *must* have the same layout in 32bit
     33  * and 64bit environments: this means that all fields must be explicitly
     34  * sized types and aligned to their sizes, and the structs must be
     35  * a multiple of eight bytes long.
     36  *
     37  * Only the state necessary for saving and restoring (i.e. fields
     38  * that are analogous to actual hardware state) should go in this file.
     39  * Internal mechanisms should be kept in Xen-private headers.
     40  */
     41 
     42 #if !defined(__GNUC__) || defined(__STRICT_ANSI__)
     43 #error "Anonymous structs/unions are a GNU extension."
     44 #endif
     45 
     46 /*
     47  * Each entry is preceded by a descriptor giving its type and length
     48  */
     49 struct hvm_save_descriptor {
     50     uint16_t typecode;          /* Used to demux the various types below */
     51     uint16_t instance;          /* Further demux within a type */
     52     uint32_t length;            /* In bytes, *not* including this descriptor */
     53 };
     54 
     55 
     56 /*
     57  * Each entry has a datatype associated with it: for example, the CPU state
     58  * is saved as a HVM_SAVE_TYPE(CPU), which has HVM_SAVE_LENGTH(CPU),
     59  * and is identified by a descriptor with typecode HVM_SAVE_CODE(CPU).
     60  * DECLARE_HVM_SAVE_TYPE binds these things together with some type-system
     61  * ugliness.
     62  */
     63 
     64 #ifdef __XEN__
     65 # define DECLARE_HVM_SAVE_TYPE_COMPAT(_x, _code, _type, _ctype, _fix)     \
     66     static inline int __HVM_SAVE_FIX_COMPAT_##_x(void *h, uint32_t size)  \
     67         { return _fix(h, size); }                                         \
     68     struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[2];};  \
     69     struct __HVM_SAVE_TYPE_COMPAT_##_x { _ctype t; }
     70 
     71 # include <xen/lib.h> /* BUG() */
     72 # define DECLARE_HVM_SAVE_TYPE(_x, _code, _type)                         \
     73     static inline int __HVM_SAVE_FIX_COMPAT_##_x(void *h, uint32_t size) \
     74         { BUG(); return -1; }                                            \
     75     struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[1];}; \
     76     struct __HVM_SAVE_TYPE_COMPAT_##_x { _type t; }
     77 #else
     78 # define DECLARE_HVM_SAVE_TYPE_COMPAT(_x, _code, _type, _ctype, _fix)     \
     79     struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[2];}
     80 
     81 # define DECLARE_HVM_SAVE_TYPE(_x, _code, _type)                         \
     82     struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; char cpt[1];}
     83 #endif
     84 
     85 #define HVM_SAVE_TYPE(_x) typeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->t)
     86 #define HVM_SAVE_LENGTH(_x) (sizeof (HVM_SAVE_TYPE(_x)))
     87 #define HVM_SAVE_CODE(_x) (sizeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->c))
     88 
     89 #ifdef __XEN__
     90 # define HVM_SAVE_TYPE_COMPAT(_x) typeof (((struct __HVM_SAVE_TYPE_COMPAT_##_x *)(0))->t)
     91 # define HVM_SAVE_LENGTH_COMPAT(_x) (sizeof (HVM_SAVE_TYPE_COMPAT(_x)))
     92 
     93 # define HVM_SAVE_HAS_COMPAT(_x) (sizeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->cpt)-1)
     94 # define HVM_SAVE_FIX_COMPAT(_x, _dst, _size) __HVM_SAVE_FIX_COMPAT_##_x(_dst, _size)
     95 #endif
     96 
     97 /*
     98  * The series of save records is teminated by a zero-type, zero-length
     99  * descriptor.
    100  */
    101 
    102 struct hvm_save_end {};
    103 DECLARE_HVM_SAVE_TYPE(END, 0, struct hvm_save_end);
    104 
    105 #if defined(__i386__) || defined(__x86_64__)
    106 #include "../arch-x86/hvm/save.h"
    107 #elif defined(__arm__) || defined(__aarch64__)
    108 #include "../arch-arm/hvm/save.h"
    109 #else
    110 #error "unsupported architecture"
    111 #endif
    112 
    113 #endif /* __XEN_PUBLIC_HVM_SAVE_H__ */
    114