xref: /freebsd/sys/contrib/xen/hvm/save.h (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
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