Merge remote-tracking branch 'remotes/kraxel/tags/pull-vnc-20150216-1' into staging
[qemu.git] / migration / vmstate.c
blobe5388f0596a354b89a6778453078546dd4fc6257
1 #include "qemu-common.h"
2 #include "migration/migration.h"
3 #include "migration/qemu-file.h"
4 #include "migration/vmstate.h"
5 #include "qemu/bitops.h"
6 #include "qemu/error-report.h"
7 #include "trace.h"
8 #include "qjson.h"
10 static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
11 void *opaque, QJSON *vmdesc);
12 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
13 void *opaque);
15 static int vmstate_n_elems(void *opaque, VMStateField *field)
17 int n_elems = 1;
19 if (field->flags & VMS_ARRAY) {
20 n_elems = field->num;
21 } else if (field->flags & VMS_VARRAY_INT32) {
22 n_elems = *(int32_t *)(opaque+field->num_offset);
23 } else if (field->flags & VMS_VARRAY_UINT32) {
24 n_elems = *(uint32_t *)(opaque+field->num_offset);
25 } else if (field->flags & VMS_VARRAY_UINT16) {
26 n_elems = *(uint16_t *)(opaque+field->num_offset);
27 } else if (field->flags & VMS_VARRAY_UINT8) {
28 n_elems = *(uint8_t *)(opaque+field->num_offset);
31 return n_elems;
34 static int vmstate_size(void *opaque, VMStateField *field)
36 int size = field->size;
38 if (field->flags & VMS_VBUFFER) {
39 size = *(int32_t *)(opaque+field->size_offset);
40 if (field->flags & VMS_MULTIPLY) {
41 size *= field->size;
45 return size;
48 static void *vmstate_base_addr(void *opaque, VMStateField *field, bool alloc)
50 void *base_addr = opaque + field->offset;
52 if (field->flags & VMS_POINTER) {
53 if (alloc && (field->flags & VMS_ALLOC)) {
54 gsize size = 0;
55 if (field->flags & VMS_VBUFFER) {
56 size = vmstate_size(opaque, field);
57 } else {
58 int n_elems = vmstate_n_elems(opaque, field);
59 if (n_elems) {
60 size = n_elems * field->size;
63 if (size) {
64 *((void **)base_addr + field->start) = g_malloc(size);
67 base_addr = *(void **)base_addr + field->start;
70 return base_addr;
73 int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
74 void *opaque, int version_id)
76 VMStateField *field = vmsd->fields;
77 int ret = 0;
79 trace_vmstate_load_state(vmsd->name, version_id);
80 if (version_id > vmsd->version_id) {
81 trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL);
82 return -EINVAL;
84 if (version_id < vmsd->minimum_version_id) {
85 if (vmsd->load_state_old &&
86 version_id >= vmsd->minimum_version_id_old) {
87 ret = vmsd->load_state_old(f, opaque, version_id);
88 trace_vmstate_load_state_end(vmsd->name, "old path", ret);
89 return ret;
91 trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL);
92 return -EINVAL;
94 if (vmsd->pre_load) {
95 int ret = vmsd->pre_load(opaque);
96 if (ret) {
97 return ret;
100 while (field->name) {
101 trace_vmstate_load_state_field(vmsd->name, field->name);
102 if ((field->field_exists &&
103 field->field_exists(opaque, version_id)) ||
104 (!field->field_exists &&
105 field->version_id <= version_id)) {
106 void *base_addr = vmstate_base_addr(opaque, field, true);
107 int i, n_elems = vmstate_n_elems(opaque, field);
108 int size = vmstate_size(opaque, field);
110 for (i = 0; i < n_elems; i++) {
111 void *addr = base_addr + size * i;
113 if (field->flags & VMS_ARRAY_OF_POINTER) {
114 addr = *(void **)addr;
116 if (field->flags & VMS_STRUCT) {
117 ret = vmstate_load_state(f, field->vmsd, addr,
118 field->vmsd->version_id);
119 } else {
120 ret = field->info->get(f, addr, size);
123 if (ret >= 0) {
124 ret = qemu_file_get_error(f);
126 if (ret < 0) {
127 qemu_file_set_error(f, ret);
128 trace_vmstate_load_field_error(field->name, ret);
129 return ret;
132 } else if (field->flags & VMS_MUST_EXIST) {
133 error_report("Input validation failed: %s/%s",
134 vmsd->name, field->name);
135 return -1;
137 field++;
139 ret = vmstate_subsection_load(f, vmsd, opaque);
140 if (ret != 0) {
141 return ret;
143 if (vmsd->post_load) {
144 ret = vmsd->post_load(opaque, version_id);
146 trace_vmstate_load_state_end(vmsd->name, "end", ret);
147 return ret;
150 static int vmfield_name_num(VMStateField *start, VMStateField *search)
152 VMStateField *field;
153 int found = 0;
155 for (field = start; field->name; field++) {
156 if (!strcmp(field->name, search->name)) {
157 if (field == search) {
158 return found;
160 found++;
164 return -1;
167 static bool vmfield_name_is_unique(VMStateField *start, VMStateField *search)
169 VMStateField *field;
170 int found = 0;
172 for (field = start; field->name; field++) {
173 if (!strcmp(field->name, search->name)) {
174 found++;
175 /* name found more than once, so it's not unique */
176 if (found > 1) {
177 return false;
182 return true;
185 static const char *vmfield_get_type_name(VMStateField *field)
187 const char *type = "unknown";
189 if (field->flags & VMS_STRUCT) {
190 type = "struct";
191 } else if (field->info->name) {
192 type = field->info->name;
195 return type;
198 static bool vmsd_can_compress(VMStateField *field)
200 if (field->field_exists) {
201 /* Dynamically existing fields mess up compression */
202 return false;
205 if (field->flags & VMS_STRUCT) {
206 VMStateField *sfield = field->vmsd->fields;
207 while (sfield->name) {
208 if (!vmsd_can_compress(sfield)) {
209 /* Child elements can't compress, so can't we */
210 return false;
212 sfield++;
215 if (field->vmsd->subsections) {
216 /* Subsections may come and go, better don't compress */
217 return false;
221 return true;
224 static void vmsd_desc_field_start(const VMStateDescription *vmsd, QJSON *vmdesc,
225 VMStateField *field, int i, int max)
227 char *name, *old_name;
228 bool is_array = max > 1;
229 bool can_compress = vmsd_can_compress(field);
231 if (!vmdesc) {
232 return;
235 name = g_strdup(field->name);
237 /* Field name is not unique, need to make it unique */
238 if (!vmfield_name_is_unique(vmsd->fields, field)) {
239 int num = vmfield_name_num(vmsd->fields, field);
240 old_name = name;
241 name = g_strdup_printf("%s[%d]", name, num);
242 g_free(old_name);
245 json_start_object(vmdesc, NULL);
246 json_prop_str(vmdesc, "name", name);
247 if (is_array) {
248 if (can_compress) {
249 json_prop_int(vmdesc, "array_len", max);
250 } else {
251 json_prop_int(vmdesc, "index", i);
254 json_prop_str(vmdesc, "type", vmfield_get_type_name(field));
256 if (field->flags & VMS_STRUCT) {
257 json_start_object(vmdesc, "struct");
260 g_free(name);
263 static void vmsd_desc_field_end(const VMStateDescription *vmsd, QJSON *vmdesc,
264 VMStateField *field, size_t size, int i)
266 if (!vmdesc) {
267 return;
270 if (field->flags & VMS_STRUCT) {
271 /* We printed a struct in between, close its child object */
272 json_end_object(vmdesc);
275 json_prop_int(vmdesc, "size", size);
276 json_end_object(vmdesc);
279 void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
280 void *opaque, QJSON *vmdesc)
282 VMStateField *field = vmsd->fields;
284 if (vmsd->pre_save) {
285 vmsd->pre_save(opaque);
288 if (vmdesc) {
289 json_prop_str(vmdesc, "vmsd_name", vmsd->name);
290 json_prop_int(vmdesc, "version", vmsd->version_id);
291 json_start_array(vmdesc, "fields");
294 while (field->name) {
295 if (!field->field_exists ||
296 field->field_exists(opaque, vmsd->version_id)) {
297 void *base_addr = vmstate_base_addr(opaque, field, false);
298 int i, n_elems = vmstate_n_elems(opaque, field);
299 int size = vmstate_size(opaque, field);
300 int64_t old_offset, written_bytes;
301 QJSON *vmdesc_loop = vmdesc;
303 for (i = 0; i < n_elems; i++) {
304 void *addr = base_addr + size * i;
306 vmsd_desc_field_start(vmsd, vmdesc_loop, field, i, n_elems);
307 old_offset = qemu_ftell_fast(f);
309 if (field->flags & VMS_ARRAY_OF_POINTER) {
310 addr = *(void **)addr;
312 if (field->flags & VMS_STRUCT) {
313 vmstate_save_state(f, field->vmsd, addr, vmdesc_loop);
314 } else {
315 field->info->put(f, addr, size);
318 written_bytes = qemu_ftell_fast(f) - old_offset;
319 vmsd_desc_field_end(vmsd, vmdesc_loop, field, written_bytes, i);
321 /* Compressed arrays only care about the first element */
322 if (vmdesc_loop && vmsd_can_compress(field)) {
323 vmdesc_loop = NULL;
326 } else {
327 if (field->flags & VMS_MUST_EXIST) {
328 error_report("Output state validation failed: %s/%s",
329 vmsd->name, field->name);
330 assert(!(field->flags & VMS_MUST_EXIST));
333 field++;
336 if (vmdesc) {
337 json_end_array(vmdesc);
340 vmstate_subsection_save(f, vmsd, opaque, vmdesc);
343 static const VMStateDescription *
344 vmstate_get_subsection(const VMStateSubsection *sub, char *idstr)
346 while (sub && sub->needed) {
347 if (strcmp(idstr, sub->vmsd->name) == 0) {
348 return sub->vmsd;
350 sub++;
352 return NULL;
355 static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd,
356 void *opaque)
358 trace_vmstate_subsection_load(vmsd->name);
360 while (qemu_peek_byte(f, 0) == QEMU_VM_SUBSECTION) {
361 char idstr[256];
362 int ret;
363 uint8_t version_id, len, size;
364 const VMStateDescription *sub_vmsd;
366 len = qemu_peek_byte(f, 1);
367 if (len < strlen(vmsd->name) + 1) {
368 /* subsection name has be be "section_name/a" */
369 trace_vmstate_subsection_load_bad(vmsd->name, "(short)");
370 return 0;
372 size = qemu_peek_buffer(f, (uint8_t *)idstr, len, 2);
373 if (size != len) {
374 trace_vmstate_subsection_load_bad(vmsd->name, "(peek fail)");
375 return 0;
377 idstr[size] = 0;
379 if (strncmp(vmsd->name, idstr, strlen(vmsd->name)) != 0) {
380 trace_vmstate_subsection_load_bad(vmsd->name, idstr);
381 /* it don't have a valid subsection name */
382 return 0;
384 sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr);
385 if (sub_vmsd == NULL) {
386 trace_vmstate_subsection_load_bad(vmsd->name, "(lookup)");
387 return -ENOENT;
389 qemu_file_skip(f, 1); /* subsection */
390 qemu_file_skip(f, 1); /* len */
391 qemu_file_skip(f, len); /* idstr */
392 version_id = qemu_get_be32(f);
394 ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
395 if (ret) {
396 trace_vmstate_subsection_load_bad(vmsd->name, "(child)");
397 return ret;
401 trace_vmstate_subsection_load_good(vmsd->name);
402 return 0;
405 static void vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd,
406 void *opaque, QJSON *vmdesc)
408 const VMStateSubsection *sub = vmsd->subsections;
409 bool subsection_found = false;
411 while (sub && sub->needed) {
412 if (sub->needed(opaque)) {
413 const VMStateDescription *vmsd = sub->vmsd;
414 uint8_t len;
416 if (vmdesc) {
417 /* Only create subsection array when we have any */
418 if (!subsection_found) {
419 json_start_array(vmdesc, "subsections");
420 subsection_found = true;
423 json_start_object(vmdesc, NULL);
426 qemu_put_byte(f, QEMU_VM_SUBSECTION);
427 len = strlen(vmsd->name);
428 qemu_put_byte(f, len);
429 qemu_put_buffer(f, (uint8_t *)vmsd->name, len);
430 qemu_put_be32(f, vmsd->version_id);
431 vmstate_save_state(f, vmsd, opaque, vmdesc);
433 if (vmdesc) {
434 json_end_object(vmdesc);
437 sub++;
440 if (vmdesc && subsection_found) {
441 json_end_array(vmdesc);
445 /* bool */
447 static int get_bool(QEMUFile *f, void *pv, size_t size)
449 bool *v = pv;
450 *v = qemu_get_byte(f);
451 return 0;
454 static void put_bool(QEMUFile *f, void *pv, size_t size)
456 bool *v = pv;
457 qemu_put_byte(f, *v);
460 const VMStateInfo vmstate_info_bool = {
461 .name = "bool",
462 .get = get_bool,
463 .put = put_bool,
466 /* 8 bit int */
468 static int get_int8(QEMUFile *f, void *pv, size_t size)
470 int8_t *v = pv;
471 qemu_get_s8s(f, v);
472 return 0;
475 static void put_int8(QEMUFile *f, void *pv, size_t size)
477 int8_t *v = pv;
478 qemu_put_s8s(f, v);
481 const VMStateInfo vmstate_info_int8 = {
482 .name = "int8",
483 .get = get_int8,
484 .put = put_int8,
487 /* 16 bit int */
489 static int get_int16(QEMUFile *f, void *pv, size_t size)
491 int16_t *v = pv;
492 qemu_get_sbe16s(f, v);
493 return 0;
496 static void put_int16(QEMUFile *f, void *pv, size_t size)
498 int16_t *v = pv;
499 qemu_put_sbe16s(f, v);
502 const VMStateInfo vmstate_info_int16 = {
503 .name = "int16",
504 .get = get_int16,
505 .put = put_int16,
508 /* 32 bit int */
510 static int get_int32(QEMUFile *f, void *pv, size_t size)
512 int32_t *v = pv;
513 qemu_get_sbe32s(f, v);
514 return 0;
517 static void put_int32(QEMUFile *f, void *pv, size_t size)
519 int32_t *v = pv;
520 qemu_put_sbe32s(f, v);
523 const VMStateInfo vmstate_info_int32 = {
524 .name = "int32",
525 .get = get_int32,
526 .put = put_int32,
529 /* 32 bit int. See that the received value is the same than the one
530 in the field */
532 static int get_int32_equal(QEMUFile *f, void *pv, size_t size)
534 int32_t *v = pv;
535 int32_t v2;
536 qemu_get_sbe32s(f, &v2);
538 if (*v == v2) {
539 return 0;
541 return -EINVAL;
544 const VMStateInfo vmstate_info_int32_equal = {
545 .name = "int32 equal",
546 .get = get_int32_equal,
547 .put = put_int32,
550 /* 32 bit int. Check that the received value is non-negative
551 * and less than or equal to the one in the field.
554 static int get_int32_le(QEMUFile *f, void *pv, size_t size)
556 int32_t *cur = pv;
557 int32_t loaded;
558 qemu_get_sbe32s(f, &loaded);
560 if (loaded >= 0 && loaded <= *cur) {
561 *cur = loaded;
562 return 0;
564 return -EINVAL;
567 const VMStateInfo vmstate_info_int32_le = {
568 .name = "int32 le",
569 .get = get_int32_le,
570 .put = put_int32,
573 /* 64 bit int */
575 static int get_int64(QEMUFile *f, void *pv, size_t size)
577 int64_t *v = pv;
578 qemu_get_sbe64s(f, v);
579 return 0;
582 static void put_int64(QEMUFile *f, void *pv, size_t size)
584 int64_t *v = pv;
585 qemu_put_sbe64s(f, v);
588 const VMStateInfo vmstate_info_int64 = {
589 .name = "int64",
590 .get = get_int64,
591 .put = put_int64,
594 /* 8 bit unsigned int */
596 static int get_uint8(QEMUFile *f, void *pv, size_t size)
598 uint8_t *v = pv;
599 qemu_get_8s(f, v);
600 return 0;
603 static void put_uint8(QEMUFile *f, void *pv, size_t size)
605 uint8_t *v = pv;
606 qemu_put_8s(f, v);
609 const VMStateInfo vmstate_info_uint8 = {
610 .name = "uint8",
611 .get = get_uint8,
612 .put = put_uint8,
615 /* 16 bit unsigned int */
617 static int get_uint16(QEMUFile *f, void *pv, size_t size)
619 uint16_t *v = pv;
620 qemu_get_be16s(f, v);
621 return 0;
624 static void put_uint16(QEMUFile *f, void *pv, size_t size)
626 uint16_t *v = pv;
627 qemu_put_be16s(f, v);
630 const VMStateInfo vmstate_info_uint16 = {
631 .name = "uint16",
632 .get = get_uint16,
633 .put = put_uint16,
636 /* 32 bit unsigned int */
638 static int get_uint32(QEMUFile *f, void *pv, size_t size)
640 uint32_t *v = pv;
641 qemu_get_be32s(f, v);
642 return 0;
645 static void put_uint32(QEMUFile *f, void *pv, size_t size)
647 uint32_t *v = pv;
648 qemu_put_be32s(f, v);
651 const VMStateInfo vmstate_info_uint32 = {
652 .name = "uint32",
653 .get = get_uint32,
654 .put = put_uint32,
657 /* 32 bit uint. See that the received value is the same than the one
658 in the field */
660 static int get_uint32_equal(QEMUFile *f, void *pv, size_t size)
662 uint32_t *v = pv;
663 uint32_t v2;
664 qemu_get_be32s(f, &v2);
666 if (*v == v2) {
667 return 0;
669 return -EINVAL;
672 const VMStateInfo vmstate_info_uint32_equal = {
673 .name = "uint32 equal",
674 .get = get_uint32_equal,
675 .put = put_uint32,
678 /* 64 bit unsigned int */
680 static int get_uint64(QEMUFile *f, void *pv, size_t size)
682 uint64_t *v = pv;
683 qemu_get_be64s(f, v);
684 return 0;
687 static void put_uint64(QEMUFile *f, void *pv, size_t size)
689 uint64_t *v = pv;
690 qemu_put_be64s(f, v);
693 const VMStateInfo vmstate_info_uint64 = {
694 .name = "uint64",
695 .get = get_uint64,
696 .put = put_uint64,
699 /* 64 bit unsigned int. See that the received value is the same than the one
700 in the field */
702 static int get_uint64_equal(QEMUFile *f, void *pv, size_t size)
704 uint64_t *v = pv;
705 uint64_t v2;
706 qemu_get_be64s(f, &v2);
708 if (*v == v2) {
709 return 0;
711 return -EINVAL;
714 const VMStateInfo vmstate_info_uint64_equal = {
715 .name = "int64 equal",
716 .get = get_uint64_equal,
717 .put = put_uint64,
720 /* 8 bit int. See that the received value is the same than the one
721 in the field */
723 static int get_uint8_equal(QEMUFile *f, void *pv, size_t size)
725 uint8_t *v = pv;
726 uint8_t v2;
727 qemu_get_8s(f, &v2);
729 if (*v == v2) {
730 return 0;
732 return -EINVAL;
735 const VMStateInfo vmstate_info_uint8_equal = {
736 .name = "uint8 equal",
737 .get = get_uint8_equal,
738 .put = put_uint8,
741 /* 16 bit unsigned int int. See that the received value is the same than the one
742 in the field */
744 static int get_uint16_equal(QEMUFile *f, void *pv, size_t size)
746 uint16_t *v = pv;
747 uint16_t v2;
748 qemu_get_be16s(f, &v2);
750 if (*v == v2) {
751 return 0;
753 return -EINVAL;
756 const VMStateInfo vmstate_info_uint16_equal = {
757 .name = "uint16 equal",
758 .get = get_uint16_equal,
759 .put = put_uint16,
762 /* floating point */
764 static int get_float64(QEMUFile *f, void *pv, size_t size)
766 float64 *v = pv;
768 *v = make_float64(qemu_get_be64(f));
769 return 0;
772 static void put_float64(QEMUFile *f, void *pv, size_t size)
774 uint64_t *v = pv;
776 qemu_put_be64(f, float64_val(*v));
779 const VMStateInfo vmstate_info_float64 = {
780 .name = "float64",
781 .get = get_float64,
782 .put = put_float64,
785 /* uint8_t buffers */
787 static int get_buffer(QEMUFile *f, void *pv, size_t size)
789 uint8_t *v = pv;
790 qemu_get_buffer(f, v, size);
791 return 0;
794 static void put_buffer(QEMUFile *f, void *pv, size_t size)
796 uint8_t *v = pv;
797 qemu_put_buffer(f, v, size);
800 const VMStateInfo vmstate_info_buffer = {
801 .name = "buffer",
802 .get = get_buffer,
803 .put = put_buffer,
806 /* unused buffers: space that was used for some fields that are
807 not useful anymore */
809 static int get_unused_buffer(QEMUFile *f, void *pv, size_t size)
811 uint8_t buf[1024];
812 int block_len;
814 while (size > 0) {
815 block_len = MIN(sizeof(buf), size);
816 size -= block_len;
817 qemu_get_buffer(f, buf, block_len);
819 return 0;
822 static void put_unused_buffer(QEMUFile *f, void *pv, size_t size)
824 static const uint8_t buf[1024];
825 int block_len;
827 while (size > 0) {
828 block_len = MIN(sizeof(buf), size);
829 size -= block_len;
830 qemu_put_buffer(f, buf, block_len);
834 const VMStateInfo vmstate_info_unused_buffer = {
835 .name = "unused_buffer",
836 .get = get_unused_buffer,
837 .put = put_unused_buffer,
840 /* bitmaps (as defined by bitmap.h). Note that size here is the size
841 * of the bitmap in bits. The on-the-wire format of a bitmap is 64
842 * bit words with the bits in big endian order. The in-memory format
843 * is an array of 'unsigned long', which may be either 32 or 64 bits.
845 /* This is the number of 64 bit words sent over the wire */
846 #define BITS_TO_U64S(nr) DIV_ROUND_UP(nr, 64)
847 static int get_bitmap(QEMUFile *f, void *pv, size_t size)
849 unsigned long *bmp = pv;
850 int i, idx = 0;
851 for (i = 0; i < BITS_TO_U64S(size); i++) {
852 uint64_t w = qemu_get_be64(f);
853 bmp[idx++] = w;
854 if (sizeof(unsigned long) == 4 && idx < BITS_TO_LONGS(size)) {
855 bmp[idx++] = w >> 32;
858 return 0;
861 static void put_bitmap(QEMUFile *f, void *pv, size_t size)
863 unsigned long *bmp = pv;
864 int i, idx = 0;
865 for (i = 0; i < BITS_TO_U64S(size); i++) {
866 uint64_t w = bmp[idx++];
867 if (sizeof(unsigned long) == 4 && idx < BITS_TO_LONGS(size)) {
868 w |= ((uint64_t)bmp[idx++]) << 32;
870 qemu_put_be64(f, w);
874 const VMStateInfo vmstate_info_bitmap = {
875 .name = "bitmap",
876 .get = get_bitmap,
877 .put = put_bitmap,