1/* SPDX-License-Identifier: BSD-3-Clause */
2/*
3 * QEMU migration/snapshot declarations
4 *
5 * Copyright (c) 2009-2011 Red Hat, Inc.
6 *
7 * Original author: Juan Quintela <quintela@redhat.com>
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer.
16 *
17 * 2. Redistributions in binary form must reproduce the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer in the documentation and/or other materials provided
20 * with the distribution.
21 *
22 * 3. Neither the name of the copyright holder nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
27 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
28 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
29 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
30 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
31 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
32 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
33 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
35 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
37 * OF THE POSSIBILITY OF SUCH DAMAGE.
38 */
39#ifndef VMSTATE_H_
40#define VMSTATE_H_
41
42#include <unistd.h>
43#include <stdint.h>
44#include <stdbool.h>
45#include "slirp.h"
46#include "stream.h"
47
48#define stringify(s) tostring(s)
49#define tostring(s) #s
50
51typedef struct VMStateInfo VMStateInfo;
52typedef struct VMStateDescription VMStateDescription;
53typedef struct VMStateField VMStateField;
54
55int slirp_vmstate_save_state(SlirpOStream *f, const VMStateDescription *vmsd,
56 void *opaque);
57int slirp_vmstate_load_state(SlirpIStream *f, const VMStateDescription *vmsd,
58 void *opaque, int version_id);
59
60/* VMStateInfo allows customized migration of objects that don't fit in
61 * any category in VMStateFlags. Additional information is always passed
62 * into get and put in terms of field and vmdesc parameters. However
63 * these two parameters should only be used in cases when customized
64 * handling is needed, such as QTAILQ. For primitive data types such as
65 * integer, field and vmdesc parameters should be ignored inside get/put.
66 */
67struct VMStateInfo {
68 const char *name;
69 int (*get)(SlirpIStream *f, void *pv, size_t size,
70 const VMStateField *field);
71 int (*put)(SlirpOStream *f, void *pv, size_t size,
72 const VMStateField *field);
73};
74
75enum VMStateFlags {
76 /* Ignored */
77 VMS_SINGLE = 0x001,
78
79 /* The struct member at opaque + VMStateField.offset is a pointer
80 * to the actual field (e.g. struct a { uint8_t *b;
81 * }). Dereference the pointer before using it as basis for
82 * further pointer arithmetic (see e.g. VMS_ARRAY). Does not
83 * affect the meaning of VMStateField.num_offset or
84 * VMStateField.size_offset; see VMS_VARRAY* and VMS_VBUFFER for
85 * those. */
86 VMS_POINTER = 0x002,
87
88 /* The field is an array of fixed size. VMStateField.num contains
89 * the number of entries in the array. The size of each entry is
90 * given by VMStateField.size and / or opaque +
91 * VMStateField.size_offset; see VMS_VBUFFER and
92 * VMS_MULTIPLY. Each array entry will be processed individually
93 * (VMStateField.info.get()/put() if VMS_STRUCT is not set,
94 * recursion into VMStateField.vmsd if VMS_STRUCT is set). May not
95 * be combined with VMS_VARRAY*. */
96 VMS_ARRAY = 0x004,
97
98 /* The field is itself a struct, containing one or more
99 * fields. Recurse into VMStateField.vmsd. Most useful in
100 * combination with VMS_ARRAY / VMS_VARRAY*, recursing into each
101 * array entry. */
102 VMS_STRUCT = 0x008,
103
104 /* The field is an array of variable size. The int32_t at opaque +
105 * VMStateField.num_offset contains the number of entries in the
106 * array. See the VMS_ARRAY description regarding array handling
107 * in general. May not be combined with VMS_ARRAY or any other
108 * VMS_VARRAY*. */
109 VMS_VARRAY_INT32 = 0x010,
110
111 /* Ignored */
112 VMS_BUFFER = 0x020,
113
114 /* The field is a (fixed-size or variable-size) array of pointers
115 * (e.g. struct a { uint8_t *b[]; }). Dereference each array entry
116 * before using it. Note: Does not imply any one of VMS_ARRAY /
117 * VMS_VARRAY*; these need to be set explicitly. */
118 VMS_ARRAY_OF_POINTER = 0x040,
119
120 /* The field is an array of variable size. The uint16_t at opaque
121 * + VMStateField.num_offset (subject to VMS_MULTIPLY_ELEMENTS)
122 * contains the number of entries in the array. See the VMS_ARRAY
123 * description regarding array handling in general. May not be
124 * combined with VMS_ARRAY or any other VMS_VARRAY*. */
125 VMS_VARRAY_UINT16 = 0x080,
126
127 /* The size of the individual entries (a single array entry if
128 * VMS_ARRAY or any of VMS_VARRAY* are set, or the field itself if
129 * neither is set) is variable (i.e. not known at compile-time),
130 * but the same for all entries. Use the int32_t at opaque +
131 * VMStateField.size_offset (subject to VMS_MULTIPLY) to determine
132 * the size of each (and every) entry. */
133 VMS_VBUFFER = 0x100,
134
135 /* Multiply the entry size given by the int32_t at opaque +
136 * VMStateField.size_offset (see VMS_VBUFFER description) with
137 * VMStateField.size to determine the number of bytes to be
138 * allocated. Only valid in combination with VMS_VBUFFER. */
139 VMS_MULTIPLY = 0x200,
140
141 /* The field is an array of variable size. The uint8_t at opaque +
142 * VMStateField.num_offset (subject to VMS_MULTIPLY_ELEMENTS)
143 * contains the number of entries in the array. See the VMS_ARRAY
144 * description regarding array handling in general. May not be
145 * combined with VMS_ARRAY or any other VMS_VARRAY*. */
146 VMS_VARRAY_UINT8 = 0x400,
147
148 /* The field is an array of variable size. The uint32_t at opaque
149 * + VMStateField.num_offset (subject to VMS_MULTIPLY_ELEMENTS)
150 * contains the number of entries in the array. See the VMS_ARRAY
151 * description regarding array handling in general. May not be
152 * combined with VMS_ARRAY or any other VMS_VARRAY*. */
153 VMS_VARRAY_UINT32 = 0x800,
154
155 /* Fail loading the serialised VM state if this field is missing
156 * from the input. */
157 VMS_MUST_EXIST = 0x1000,
158
159 /* When loading serialised VM state, allocate memory for the
160 * (entire) field. Only valid in combination with
161 * VMS_POINTER. Note: Not all combinations with other flags are
162 * currently supported, e.g. VMS_ALLOC|VMS_ARRAY_OF_POINTER won't
163 * cause the individual entries to be allocated. */
164 VMS_ALLOC = 0x2000,
165
166 /* Multiply the number of entries given by the integer at opaque +
167 * VMStateField.num_offset (see VMS_VARRAY*) with VMStateField.num
168 * to determine the number of entries in the array. Only valid in
169 * combination with one of VMS_VARRAY*. */
170 VMS_MULTIPLY_ELEMENTS = 0x4000,
171
172 /* A structure field that is like VMS_STRUCT, but uses
173 * VMStateField.struct_version_id to tell which version of the
174 * structure we are referencing to use. */
175 VMS_VSTRUCT = 0x8000,
176};
177
178struct VMStateField {
179 const char *name;
180 size_t offset;
181 size_t size;
182 size_t start;
183 int num;
184 size_t num_offset;
185 size_t size_offset;
186 const VMStateInfo *info;
187 enum VMStateFlags flags;
188 const VMStateDescription *vmsd;
189 int version_id;
190 int struct_version_id;
191 bool (*field_exists)(void *opaque, int version_id);
192};
193
194struct VMStateDescription {
195 const char *name;
196 int version_id;
197 int (*pre_load)(void *opaque);
198 int (*post_load)(void *opaque, int version_id);
199 int (*pre_save)(void *opaque);
200 VMStateField *fields;
201};
202
203
204extern const VMStateInfo slirp_vmstate_info_int16;
205extern const VMStateInfo slirp_vmstate_info_int32;
206extern const VMStateInfo slirp_vmstate_info_uint8;
207extern const VMStateInfo slirp_vmstate_info_uint16;
208extern const VMStateInfo slirp_vmstate_info_uint32;
209
210/** Put this in the stream when migrating a null pointer.*/
211#define VMS_NULLPTR_MARKER (0x30U) /* '0' */
212extern const VMStateInfo slirp_vmstate_info_nullptr;
213
214extern const VMStateInfo slirp_vmstate_info_buffer;
215extern const VMStateInfo slirp_vmstate_info_tmp;
216
217#define type_check_array(t1, t2, n) ((t1(*)[n])0 - (t2 *)0)
218#define type_check_pointer(t1, t2) ((t1 **)0 - (t2 *)0)
219#define typeof_field(type, field) typeof(((type *)0)->field)
220#define type_check(t1, t2) ((t1 *)0 - (t2 *)0)
221
222#define vmstate_offset_value(_state, _field, _type) \
223 (offsetof(_state, _field) + type_check(_type, typeof_field(_state, _field)))
224
225#define vmstate_offset_pointer(_state, _field, _type) \
226 (offsetof(_state, _field) + \
227 type_check_pointer(_type, typeof_field(_state, _field)))
228
229#define vmstate_offset_array(_state, _field, _type, _num) \
230 (offsetof(_state, _field) + \
231 type_check_array(_type, typeof_field(_state, _field), _num))
232
233#define vmstate_offset_buffer(_state, _field) \
234 vmstate_offset_array(_state, _field, uint8_t, \
235 sizeof(typeof_field(_state, _field)))
236
237/* In the macros below, if there is a _version, that means the macro's
238 * field will be processed only if the version being received is >=
239 * the _version specified. In general, if you add a new field, you
240 * would increment the structure's version and put that version
241 * number into the new field so it would only be processed with the
242 * new version.
243 *
244 * In particular, for VMSTATE_STRUCT() and friends the _version does
245 * *NOT* pick the version of the sub-structure. It works just as
246 * specified above. The version of the top-level structure received
247 * is passed down to all sub-structures. This means that the
248 * sub-structures must have version that are compatible with all the
249 * structures that use them.
250 *
251 * If you want to specify the version of the sub-structure, use
252 * VMSTATE_VSTRUCT(), which allows the specific sub-structure version
253 * to be directly specified.
254 */
255
256#define VMSTATE_SINGLE_TEST(_field, _state, _test, _version, _info, _type) \
257 { \
258 .name = (stringify(_field)), .version_id = (_version), \
259 .field_exists = (_test), .size = sizeof(_type), .info = &(_info), \
260 .flags = VMS_SINGLE, \
261 .offset = vmstate_offset_value(_state, _field, _type), \
262 }
263
264#define VMSTATE_ARRAY(_field, _state, _num, _version, _info, _type) \
265 { \
266 .name = (stringify(_field)), .version_id = (_version), .num = (_num), \
267 .info = &(_info), .size = sizeof(_type), .flags = VMS_ARRAY, \
268 .offset = vmstate_offset_array(_state, _field, _type, _num), \
269 }
270
271#define VMSTATE_STRUCT_TEST(_field, _state, _test, _version, _vmsd, _type) \
272 { \
273 .name = (stringify(_field)), .version_id = (_version), \
274 .field_exists = (_test), .vmsd = &(_vmsd), .size = sizeof(_type), \
275 .flags = VMS_STRUCT, \
276 .offset = vmstate_offset_value(_state, _field, _type), \
277 }
278
279#define VMSTATE_STRUCT_POINTER_V(_field, _state, _version, _vmsd, _type) \
280 { \
281 .name = (stringify(_field)), .version_id = (_version), \
282 .vmsd = &(_vmsd), .size = sizeof(_type *), \
283 .flags = VMS_STRUCT | VMS_POINTER, \
284 .offset = vmstate_offset_pointer(_state, _field, _type), \
285 }
286
287#define VMSTATE_STRUCT_ARRAY_TEST(_field, _state, _num, _test, _version, \
288 _vmsd, _type) \
289 { \
290 .name = (stringify(_field)), .num = (_num), .field_exists = (_test), \
291 .version_id = (_version), .vmsd = &(_vmsd), .size = sizeof(_type), \
292 .flags = VMS_STRUCT | VMS_ARRAY, \
293 .offset = vmstate_offset_array(_state, _field, _type, _num), \
294 }
295
296#define VMSTATE_STATIC_BUFFER(_field, _state, _version, _test, _start, _size) \
297 { \
298 .name = (stringify(_field)), .version_id = (_version), \
299 .field_exists = (_test), .size = (_size - _start), \
300 .info = &slirp_vmstate_info_buffer, .flags = VMS_BUFFER, \
301 .offset = vmstate_offset_buffer(_state, _field) + _start, \
302 }
303
304#define VMSTATE_VBUFFER_UINT32(_field, _state, _version, _test, _field_size) \
305 { \
306 .name = (stringify(_field)), .version_id = (_version), \
307 .field_exists = (_test), \
308 .size_offset = vmstate_offset_value(_state, _field_size, uint32_t), \
309 .info = &slirp_vmstate_info_buffer, \
310 .flags = VMS_VBUFFER | VMS_POINTER, \
311 .offset = offsetof(_state, _field), \
312 }
313
314#define QEMU_BUILD_BUG_ON_STRUCT(x) \
315 struct { \
316 int : (x) ? -1 : 1; \
317 }
318
319#define QEMU_BUILD_BUG_ON_ZERO(x) \
320 (sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)) - sizeof(QEMU_BUILD_BUG_ON_STRUCT(x)))
321
322/* Allocate a temporary of type 'tmp_type', set tmp->parent to _state
323 * and execute the vmsd on the temporary. Note that we're working with
324 * the whole of _state here, not a field within it.
325 * We compile time check that:
326 * That _tmp_type contains a 'parent' member that's a pointer to the
327 * '_state' type
328 * That the pointer is right at the start of _tmp_type.
329 */
330#define VMSTATE_WITH_TMP(_state, _tmp_type, _vmsd) \
331 { \
332 .name = "tmp", \
333 .size = sizeof(_tmp_type) + \
334 QEMU_BUILD_BUG_ON_ZERO(offsetof(_tmp_type, parent) != 0) + \
335 type_check_pointer(_state, typeof_field(_tmp_type, parent)), \
336 .vmsd = &(_vmsd), .info = &slirp_vmstate_info_tmp, \
337 }
338
339#define VMSTATE_SINGLE(_field, _state, _version, _info, _type) \
340 VMSTATE_SINGLE_TEST(_field, _state, NULL, _version, _info, _type)
341
342#define VMSTATE_STRUCT(_field, _state, _version, _vmsd, _type) \
343 VMSTATE_STRUCT_TEST(_field, _state, NULL, _version, _vmsd, _type)
344
345#define VMSTATE_STRUCT_POINTER(_field, _state, _vmsd, _type) \
346 VMSTATE_STRUCT_POINTER_V(_field, _state, 0, _vmsd, _type)
347
348#define VMSTATE_STRUCT_ARRAY(_field, _state, _num, _version, _vmsd, _type) \
349 VMSTATE_STRUCT_ARRAY_TEST(_field, _state, _num, NULL, _version, _vmsd, \
350 _type)
351
352#define VMSTATE_INT16_V(_f, _s, _v) \
353 VMSTATE_SINGLE(_f, _s, _v, slirp_vmstate_info_int16, int16_t)
354#define VMSTATE_INT32_V(_f, _s, _v) \
355 VMSTATE_SINGLE(_f, _s, _v, slirp_vmstate_info_int32, int32_t)
356
357#define VMSTATE_UINT8_V(_f, _s, _v) \
358 VMSTATE_SINGLE(_f, _s, _v, slirp_vmstate_info_uint8, uint8_t)
359#define VMSTATE_UINT16_V(_f, _s, _v) \
360 VMSTATE_SINGLE(_f, _s, _v, slirp_vmstate_info_uint16, uint16_t)
361#define VMSTATE_UINT32_V(_f, _s, _v) \
362 VMSTATE_SINGLE(_f, _s, _v, slirp_vmstate_info_uint32, uint32_t)
363
364#define VMSTATE_INT16(_f, _s) VMSTATE_INT16_V(_f, _s, 0)
365#define VMSTATE_INT32(_f, _s) VMSTATE_INT32_V(_f, _s, 0)
366
367#define VMSTATE_UINT8(_f, _s) VMSTATE_UINT8_V(_f, _s, 0)
368#define VMSTATE_UINT16(_f, _s) VMSTATE_UINT16_V(_f, _s, 0)
369#define VMSTATE_UINT32(_f, _s) VMSTATE_UINT32_V(_f, _s, 0)
370
371#define VMSTATE_UINT16_TEST(_f, _s, _t) \
372 VMSTATE_SINGLE_TEST(_f, _s, _t, 0, slirp_vmstate_info_uint16, uint16_t)
373
374#define VMSTATE_UINT32_TEST(_f, _s, _t) \
375 VMSTATE_SINGLE_TEST(_f, _s, _t, 0, slirp_vmstate_info_uint32, uint32_t)
376
377#define VMSTATE_INT16_ARRAY_V(_f, _s, _n, _v) \
378 VMSTATE_ARRAY(_f, _s, _n, _v, slirp_vmstate_info_int16, int16_t)
379
380#define VMSTATE_INT16_ARRAY(_f, _s, _n) VMSTATE_INT16_ARRAY_V(_f, _s, _n, 0)
381
382#define VMSTATE_BUFFER_V(_f, _s, _v) \
383 VMSTATE_STATIC_BUFFER(_f, _s, _v, NULL, 0, sizeof(typeof_field(_s, _f)))
384
385#define VMSTATE_BUFFER(_f, _s) VMSTATE_BUFFER_V(_f, _s, 0)
386
387#define VMSTATE_END_OF_LIST() \
388 { \
389 }
390
391#endif
392