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 #define DECLARE_HVM_SAVE_TYPE(_x, _code, _type)                   \
65   struct __HVM_SAVE_TYPE_##_x { _type t; char c[_code]; }
66 
67 #define HVM_SAVE_TYPE(_x) typeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->t)
68 #define HVM_SAVE_LENGTH(_x) (sizeof (HVM_SAVE_TYPE(_x)))
69 #define HVM_SAVE_CODE(_x) (sizeof (((struct __HVM_SAVE_TYPE_##_x *)(0))->c))
70 
71 
72 /*
73  * The series of save records is teminated by a zero-type, zero-length
74  * descriptor.
75  */
76 
77 struct hvm_save_end {};
78 DECLARE_HVM_SAVE_TYPE(END, 0, struct hvm_save_end);
79 
80 #if defined(__i386__) || defined(__x86_64__)
81 #include "../arch-x86/hvm/save.h"
82 #elif defined(__ia64__)
83 #include "../arch-ia64/hvm/save.h"
84 #else
85 #error "unsupported architecture"
86 #endif
87 
88 #endif /* __XEN_PUBLIC_HVM_SAVE_H__ */
89