xref: /openbmc/qemu/dump/dump.c (revision e71d3533)
1 /*
2  * QEMU dump
3  *
4  * Copyright Fujitsu, Corp. 2011, 2012
5  *
6  * Authors:
7  *     Wen Congyang <wency@cn.fujitsu.com>
8  *
9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
10  * See the COPYING file in the top-level directory.
11  *
12  */
13 
14 #include "qemu/osdep.h"
15 #include "qemu/cutils.h"
16 #include "elf.h"
17 #include "exec/hwaddr.h"
18 #include "monitor/monitor.h"
19 #include "sysemu/kvm.h"
20 #include "sysemu/dump.h"
21 #include "sysemu/memory_mapping.h"
22 #include "sysemu/runstate.h"
23 #include "sysemu/cpus.h"
24 #include "qapi/error.h"
25 #include "qapi/qapi-commands-dump.h"
26 #include "qapi/qapi-events-dump.h"
27 #include "qapi/qmp/qerror.h"
28 #include "qemu/error-report.h"
29 #include "qemu/main-loop.h"
30 #include "hw/misc/vmcoreinfo.h"
31 #include "migration/blocker.h"
32 
33 #ifdef TARGET_X86_64
34 #include "win_dump.h"
35 #endif
36 
37 #include <zlib.h>
38 #ifdef CONFIG_LZO
39 #include <lzo/lzo1x.h>
40 #endif
41 #ifdef CONFIG_SNAPPY
42 #include <snappy-c.h>
43 #endif
44 #ifndef ELF_MACHINE_UNAME
45 #define ELF_MACHINE_UNAME "Unknown"
46 #endif
47 
48 #define MAX_GUEST_NOTE_SIZE (1 << 20) /* 1MB should be enough */
49 
50 static Error *dump_migration_blocker;
51 
52 #define ELF_NOTE_SIZE(hdr_size, name_size, desc_size)   \
53     ((DIV_ROUND_UP((hdr_size), 4) +                     \
54       DIV_ROUND_UP((name_size), 4) +                    \
55       DIV_ROUND_UP((desc_size), 4)) * 4)
56 
57 uint16_t cpu_to_dump16(DumpState *s, uint16_t val)
58 {
59     if (s->dump_info.d_endian == ELFDATA2LSB) {
60         val = cpu_to_le16(val);
61     } else {
62         val = cpu_to_be16(val);
63     }
64 
65     return val;
66 }
67 
68 uint32_t cpu_to_dump32(DumpState *s, uint32_t val)
69 {
70     if (s->dump_info.d_endian == ELFDATA2LSB) {
71         val = cpu_to_le32(val);
72     } else {
73         val = cpu_to_be32(val);
74     }
75 
76     return val;
77 }
78 
79 uint64_t cpu_to_dump64(DumpState *s, uint64_t val)
80 {
81     if (s->dump_info.d_endian == ELFDATA2LSB) {
82         val = cpu_to_le64(val);
83     } else {
84         val = cpu_to_be64(val);
85     }
86 
87     return val;
88 }
89 
90 static int dump_cleanup(DumpState *s)
91 {
92     guest_phys_blocks_free(&s->guest_phys_blocks);
93     memory_mapping_list_free(&s->list);
94     close(s->fd);
95     g_free(s->guest_note);
96     s->guest_note = NULL;
97     if (s->resume) {
98         if (s->detached) {
99             qemu_mutex_lock_iothread();
100         }
101         vm_start();
102         if (s->detached) {
103             qemu_mutex_unlock_iothread();
104         }
105     }
106     migrate_del_blocker(dump_migration_blocker);
107 
108     return 0;
109 }
110 
111 static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
112 {
113     DumpState *s = opaque;
114     size_t written_size;
115 
116     written_size = qemu_write_full(s->fd, buf, size);
117     if (written_size != size) {
118         return -errno;
119     }
120 
121     return 0;
122 }
123 
124 static void write_elf64_header(DumpState *s, Error **errp)
125 {
126     /*
127      * phnum in the elf header is 16 bit, if we have more segments we
128      * set phnum to PN_XNUM and write the real number of segments to a
129      * special section.
130      */
131     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
132     Elf64_Ehdr elf_header;
133     int ret;
134 
135     memset(&elf_header, 0, sizeof(Elf64_Ehdr));
136     memcpy(&elf_header, ELFMAG, SELFMAG);
137     elf_header.e_ident[EI_CLASS] = ELFCLASS64;
138     elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
139     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
140     elf_header.e_type = cpu_to_dump16(s, ET_CORE);
141     elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
142     elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);
143     elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
144     elf_header.e_phoff = cpu_to_dump64(s, s->phdr_offset);
145     elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
146     elf_header.e_phnum = cpu_to_dump16(s, phnum);
147     if (s->shdr_num) {
148         elf_header.e_shoff = cpu_to_dump64(s, s->shdr_offset);
149         elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
150         elf_header.e_shnum = cpu_to_dump16(s, s->shdr_num);
151     }
152 
153     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
154     if (ret < 0) {
155         error_setg_errno(errp, -ret, "dump: failed to write elf header");
156     }
157 }
158 
159 static void write_elf32_header(DumpState *s, Error **errp)
160 {
161     /*
162      * phnum in the elf header is 16 bit, if we have more segments we
163      * set phnum to PN_XNUM and write the real number of segments to a
164      * special section.
165      */
166     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
167     Elf32_Ehdr elf_header;
168     int ret;
169 
170     memset(&elf_header, 0, sizeof(Elf32_Ehdr));
171     memcpy(&elf_header, ELFMAG, SELFMAG);
172     elf_header.e_ident[EI_CLASS] = ELFCLASS32;
173     elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
174     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
175     elf_header.e_type = cpu_to_dump16(s, ET_CORE);
176     elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
177     elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);
178     elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
179     elf_header.e_phoff = cpu_to_dump32(s, s->phdr_offset);
180     elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
181     elf_header.e_phnum = cpu_to_dump16(s, phnum);
182     if (s->shdr_num) {
183         elf_header.e_shoff = cpu_to_dump32(s, s->shdr_offset);
184         elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
185         elf_header.e_shnum = cpu_to_dump16(s, s->shdr_num);
186     }
187 
188     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
189     if (ret < 0) {
190         error_setg_errno(errp, -ret, "dump: failed to write elf header");
191     }
192 }
193 
194 static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
195                              int phdr_index, hwaddr offset,
196                              hwaddr filesz, Error **errp)
197 {
198     Elf64_Phdr phdr;
199     int ret;
200 
201     memset(&phdr, 0, sizeof(Elf64_Phdr));
202     phdr.p_type = cpu_to_dump32(s, PT_LOAD);
203     phdr.p_offset = cpu_to_dump64(s, offset);
204     phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
205     phdr.p_filesz = cpu_to_dump64(s, filesz);
206     phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
207     phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
208 
209     assert(memory_mapping->length >= filesz);
210 
211     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
212     if (ret < 0) {
213         error_setg_errno(errp, -ret,
214                          "dump: failed to write program header table");
215     }
216 }
217 
218 static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
219                              int phdr_index, hwaddr offset,
220                              hwaddr filesz, Error **errp)
221 {
222     Elf32_Phdr phdr;
223     int ret;
224 
225     memset(&phdr, 0, sizeof(Elf32_Phdr));
226     phdr.p_type = cpu_to_dump32(s, PT_LOAD);
227     phdr.p_offset = cpu_to_dump32(s, offset);
228     phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
229     phdr.p_filesz = cpu_to_dump32(s, filesz);
230     phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
231     phdr.p_vaddr =
232         cpu_to_dump32(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
233 
234     assert(memory_mapping->length >= filesz);
235 
236     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
237     if (ret < 0) {
238         error_setg_errno(errp, -ret,
239                          "dump: failed to write program header table");
240     }
241 }
242 
243 static void write_elf64_note(DumpState *s, Error **errp)
244 {
245     Elf64_Phdr phdr;
246     int ret;
247 
248     memset(&phdr, 0, sizeof(Elf64_Phdr));
249     phdr.p_type = cpu_to_dump32(s, PT_NOTE);
250     phdr.p_offset = cpu_to_dump64(s, s->note_offset);
251     phdr.p_paddr = 0;
252     phdr.p_filesz = cpu_to_dump64(s, s->note_size);
253     phdr.p_memsz = cpu_to_dump64(s, s->note_size);
254     phdr.p_vaddr = 0;
255 
256     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
257     if (ret < 0) {
258         error_setg_errno(errp, -ret,
259                          "dump: failed to write program header table");
260     }
261 }
262 
263 static inline int cpu_index(CPUState *cpu)
264 {
265     return cpu->cpu_index + 1;
266 }
267 
268 static void write_guest_note(WriteCoreDumpFunction f, DumpState *s,
269                              Error **errp)
270 {
271     int ret;
272 
273     if (s->guest_note) {
274         ret = f(s->guest_note, s->guest_note_size, s);
275         if (ret < 0) {
276             error_setg(errp, "dump: failed to write guest note");
277         }
278     }
279 }
280 
281 static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
282                               Error **errp)
283 {
284     CPUState *cpu;
285     int ret;
286     int id;
287 
288     CPU_FOREACH(cpu) {
289         id = cpu_index(cpu);
290         ret = cpu_write_elf64_note(f, cpu, id, s);
291         if (ret < 0) {
292             error_setg(errp, "dump: failed to write elf notes");
293             return;
294         }
295     }
296 
297     CPU_FOREACH(cpu) {
298         ret = cpu_write_elf64_qemunote(f, cpu, s);
299         if (ret < 0) {
300             error_setg(errp, "dump: failed to write CPU status");
301             return;
302         }
303     }
304 
305     write_guest_note(f, s, errp);
306 }
307 
308 static void write_elf32_note(DumpState *s, Error **errp)
309 {
310     Elf32_Phdr phdr;
311     int ret;
312 
313     memset(&phdr, 0, sizeof(Elf32_Phdr));
314     phdr.p_type = cpu_to_dump32(s, PT_NOTE);
315     phdr.p_offset = cpu_to_dump32(s, s->note_offset);
316     phdr.p_paddr = 0;
317     phdr.p_filesz = cpu_to_dump32(s, s->note_size);
318     phdr.p_memsz = cpu_to_dump32(s, s->note_size);
319     phdr.p_vaddr = 0;
320 
321     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
322     if (ret < 0) {
323         error_setg_errno(errp, -ret,
324                          "dump: failed to write program header table");
325     }
326 }
327 
328 static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
329                               Error **errp)
330 {
331     CPUState *cpu;
332     int ret;
333     int id;
334 
335     CPU_FOREACH(cpu) {
336         id = cpu_index(cpu);
337         ret = cpu_write_elf32_note(f, cpu, id, s);
338         if (ret < 0) {
339             error_setg(errp, "dump: failed to write elf notes");
340             return;
341         }
342     }
343 
344     CPU_FOREACH(cpu) {
345         ret = cpu_write_elf32_qemunote(f, cpu, s);
346         if (ret < 0) {
347             error_setg(errp, "dump: failed to write CPU status");
348             return;
349         }
350     }
351 
352     write_guest_note(f, s, errp);
353 }
354 
355 static void write_elf_section(DumpState *s, int type, Error **errp)
356 {
357     Elf32_Shdr shdr32;
358     Elf64_Shdr shdr64;
359     int shdr_size;
360     void *shdr;
361     int ret;
362 
363     if (type == 0) {
364         shdr_size = sizeof(Elf32_Shdr);
365         memset(&shdr32, 0, shdr_size);
366         shdr32.sh_info = cpu_to_dump32(s, s->phdr_num);
367         shdr = &shdr32;
368     } else {
369         shdr_size = sizeof(Elf64_Shdr);
370         memset(&shdr64, 0, shdr_size);
371         shdr64.sh_info = cpu_to_dump32(s, s->phdr_num);
372         shdr = &shdr64;
373     }
374 
375     ret = fd_write_vmcore(shdr, shdr_size, s);
376     if (ret < 0) {
377         error_setg_errno(errp, -ret,
378                          "dump: failed to write section header table");
379     }
380 }
381 
382 static void write_data(DumpState *s, void *buf, int length, Error **errp)
383 {
384     int ret;
385 
386     ret = fd_write_vmcore(buf, length, s);
387     if (ret < 0) {
388         error_setg_errno(errp, -ret, "dump: failed to save memory");
389     } else {
390         s->written_size += length;
391     }
392 }
393 
394 /* write the memory to vmcore. 1 page per I/O. */
395 static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
396                          int64_t size, Error **errp)
397 {
398     ERRP_GUARD();
399     int64_t i;
400 
401     for (i = 0; i < size / s->dump_info.page_size; i++) {
402         write_data(s, block->host_addr + start + i * s->dump_info.page_size,
403                    s->dump_info.page_size, errp);
404         if (*errp) {
405             return;
406         }
407     }
408 
409     if ((size % s->dump_info.page_size) != 0) {
410         write_data(s, block->host_addr + start + i * s->dump_info.page_size,
411                    size % s->dump_info.page_size, errp);
412         if (*errp) {
413             return;
414         }
415     }
416 }
417 
418 /* get the memory's offset and size in the vmcore */
419 static void get_offset_range(hwaddr phys_addr,
420                              ram_addr_t mapping_length,
421                              DumpState *s,
422                              hwaddr *p_offset,
423                              hwaddr *p_filesz)
424 {
425     GuestPhysBlock *block;
426     hwaddr offset = s->memory_offset;
427     int64_t size_in_block, start;
428 
429     /* When the memory is not stored into vmcore, offset will be -1 */
430     *p_offset = -1;
431     *p_filesz = 0;
432 
433     if (s->has_filter) {
434         if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
435             return;
436         }
437     }
438 
439     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
440         if (s->has_filter) {
441             if (block->target_start >= s->begin + s->length ||
442                 block->target_end <= s->begin) {
443                 /* This block is out of the range */
444                 continue;
445             }
446 
447             if (s->begin <= block->target_start) {
448                 start = block->target_start;
449             } else {
450                 start = s->begin;
451             }
452 
453             size_in_block = block->target_end - start;
454             if (s->begin + s->length < block->target_end) {
455                 size_in_block -= block->target_end - (s->begin + s->length);
456             }
457         } else {
458             start = block->target_start;
459             size_in_block = block->target_end - block->target_start;
460         }
461 
462         if (phys_addr >= start && phys_addr < start + size_in_block) {
463             *p_offset = phys_addr - start + offset;
464 
465             /* The offset range mapped from the vmcore file must not spill over
466              * the GuestPhysBlock, clamp it. The rest of the mapping will be
467              * zero-filled in memory at load time; see
468              * <http://refspecs.linuxbase.org/elf/gabi4+/ch5.pheader.html>.
469              */
470             *p_filesz = phys_addr + mapping_length <= start + size_in_block ?
471                         mapping_length :
472                         size_in_block - (phys_addr - start);
473             return;
474         }
475 
476         offset += size_in_block;
477     }
478 }
479 
480 static void write_elf_loads(DumpState *s, Error **errp)
481 {
482     ERRP_GUARD();
483     hwaddr offset, filesz;
484     MemoryMapping *memory_mapping;
485     uint32_t phdr_index = 1;
486 
487     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
488         get_offset_range(memory_mapping->phys_addr,
489                          memory_mapping->length,
490                          s, &offset, &filesz);
491         if (s->dump_info.d_class == ELFCLASS64) {
492             write_elf64_load(s, memory_mapping, phdr_index++, offset,
493                              filesz, errp);
494         } else {
495             write_elf32_load(s, memory_mapping, phdr_index++, offset,
496                              filesz, errp);
497         }
498 
499         if (*errp) {
500             return;
501         }
502 
503         if (phdr_index >= s->phdr_num) {
504             break;
505         }
506     }
507 }
508 
509 /* write elf header, PT_NOTE and elf note to vmcore. */
510 static void dump_begin(DumpState *s, Error **errp)
511 {
512     ERRP_GUARD();
513 
514     /*
515      * the vmcore's format is:
516      *   --------------
517      *   |  elf header |
518      *   --------------
519      *   |  PT_NOTE    |
520      *   --------------
521      *   |  PT_LOAD    |
522      *   --------------
523      *   |  ......     |
524      *   --------------
525      *   |  PT_LOAD    |
526      *   --------------
527      *   |  sec_hdr    |
528      *   --------------
529      *   |  elf note   |
530      *   --------------
531      *   |  memory     |
532      *   --------------
533      *
534      * we only know where the memory is saved after we write elf note into
535      * vmcore.
536      */
537 
538     /* write elf header to vmcore */
539     if (s->dump_info.d_class == ELFCLASS64) {
540         write_elf64_header(s, errp);
541     } else {
542         write_elf32_header(s, errp);
543     }
544     if (*errp) {
545         return;
546     }
547 
548     if (s->dump_info.d_class == ELFCLASS64) {
549         /* write PT_NOTE to vmcore */
550         write_elf64_note(s, errp);
551         if (*errp) {
552             return;
553         }
554 
555         /* write all PT_LOAD to vmcore */
556         write_elf_loads(s, errp);
557         if (*errp) {
558             return;
559         }
560 
561         /* write section to vmcore */
562         if (s->shdr_num) {
563             write_elf_section(s, 1, errp);
564             if (*errp) {
565                 return;
566             }
567         }
568 
569         /* write notes to vmcore */
570         write_elf64_notes(fd_write_vmcore, s, errp);
571         if (*errp) {
572             return;
573         }
574     } else {
575         /* write PT_NOTE to vmcore */
576         write_elf32_note(s, errp);
577         if (*errp) {
578             return;
579         }
580 
581         /* write all PT_LOAD to vmcore */
582         write_elf_loads(s, errp);
583         if (*errp) {
584             return;
585         }
586 
587         /* write section to vmcore */
588         if (s->shdr_num) {
589             write_elf_section(s, 0, errp);
590             if (*errp) {
591                 return;
592             }
593         }
594 
595         /* write notes to vmcore */
596         write_elf32_notes(fd_write_vmcore, s, errp);
597         if (*errp) {
598             return;
599         }
600     }
601 }
602 
603 static int get_next_block(DumpState *s, GuestPhysBlock *block)
604 {
605     while (1) {
606         block = QTAILQ_NEXT(block, next);
607         if (!block) {
608             /* no more block */
609             return 1;
610         }
611 
612         s->start = 0;
613         s->next_block = block;
614         if (s->has_filter) {
615             if (block->target_start >= s->begin + s->length ||
616                 block->target_end <= s->begin) {
617                 /* This block is out of the range */
618                 continue;
619             }
620 
621             if (s->begin > block->target_start) {
622                 s->start = s->begin - block->target_start;
623             }
624         }
625 
626         return 0;
627     }
628 }
629 
630 /* write all memory to vmcore */
631 static void dump_iterate(DumpState *s, Error **errp)
632 {
633     ERRP_GUARD();
634     GuestPhysBlock *block;
635     int64_t size;
636 
637     do {
638         block = s->next_block;
639 
640         size = block->target_end - block->target_start;
641         if (s->has_filter) {
642             size -= s->start;
643             if (s->begin + s->length < block->target_end) {
644                 size -= block->target_end - (s->begin + s->length);
645             }
646         }
647         write_memory(s, block, s->start, size, errp);
648         if (*errp) {
649             return;
650         }
651 
652     } while (!get_next_block(s, block));
653 }
654 
655 static void create_vmcore(DumpState *s, Error **errp)
656 {
657     ERRP_GUARD();
658 
659     dump_begin(s, errp);
660     if (*errp) {
661         return;
662     }
663 
664     dump_iterate(s, errp);
665 }
666 
667 static int write_start_flat_header(int fd)
668 {
669     MakedumpfileHeader *mh;
670     int ret = 0;
671 
672     QEMU_BUILD_BUG_ON(sizeof *mh > MAX_SIZE_MDF_HEADER);
673     mh = g_malloc0(MAX_SIZE_MDF_HEADER);
674 
675     memcpy(mh->signature, MAKEDUMPFILE_SIGNATURE,
676            MIN(sizeof mh->signature, sizeof MAKEDUMPFILE_SIGNATURE));
677 
678     mh->type = cpu_to_be64(TYPE_FLAT_HEADER);
679     mh->version = cpu_to_be64(VERSION_FLAT_HEADER);
680 
681     size_t written_size;
682     written_size = qemu_write_full(fd, mh, MAX_SIZE_MDF_HEADER);
683     if (written_size != MAX_SIZE_MDF_HEADER) {
684         ret = -1;
685     }
686 
687     g_free(mh);
688     return ret;
689 }
690 
691 static int write_end_flat_header(int fd)
692 {
693     MakedumpfileDataHeader mdh;
694 
695     mdh.offset = END_FLAG_FLAT_HEADER;
696     mdh.buf_size = END_FLAG_FLAT_HEADER;
697 
698     size_t written_size;
699     written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
700     if (written_size != sizeof(mdh)) {
701         return -1;
702     }
703 
704     return 0;
705 }
706 
707 static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
708 {
709     size_t written_size;
710     MakedumpfileDataHeader mdh;
711 
712     mdh.offset = cpu_to_be64(offset);
713     mdh.buf_size = cpu_to_be64(size);
714 
715     written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
716     if (written_size != sizeof(mdh)) {
717         return -1;
718     }
719 
720     written_size = qemu_write_full(fd, buf, size);
721     if (written_size != size) {
722         return -1;
723     }
724 
725     return 0;
726 }
727 
728 static int buf_write_note(const void *buf, size_t size, void *opaque)
729 {
730     DumpState *s = opaque;
731 
732     /* note_buf is not enough */
733     if (s->note_buf_offset + size > s->note_size) {
734         return -1;
735     }
736 
737     memcpy(s->note_buf + s->note_buf_offset, buf, size);
738 
739     s->note_buf_offset += size;
740 
741     return 0;
742 }
743 
744 /*
745  * This function retrieves various sizes from an elf header.
746  *
747  * @note has to be a valid ELF note. The return sizes are unmodified
748  * (not padded or rounded up to be multiple of 4).
749  */
750 static void get_note_sizes(DumpState *s, const void *note,
751                            uint64_t *note_head_size,
752                            uint64_t *name_size,
753                            uint64_t *desc_size)
754 {
755     uint64_t note_head_sz;
756     uint64_t name_sz;
757     uint64_t desc_sz;
758 
759     if (s->dump_info.d_class == ELFCLASS64) {
760         const Elf64_Nhdr *hdr = note;
761         note_head_sz = sizeof(Elf64_Nhdr);
762         name_sz = tswap64(hdr->n_namesz);
763         desc_sz = tswap64(hdr->n_descsz);
764     } else {
765         const Elf32_Nhdr *hdr = note;
766         note_head_sz = sizeof(Elf32_Nhdr);
767         name_sz = tswap32(hdr->n_namesz);
768         desc_sz = tswap32(hdr->n_descsz);
769     }
770 
771     if (note_head_size) {
772         *note_head_size = note_head_sz;
773     }
774     if (name_size) {
775         *name_size = name_sz;
776     }
777     if (desc_size) {
778         *desc_size = desc_sz;
779     }
780 }
781 
782 static bool note_name_equal(DumpState *s,
783                             const uint8_t *note, const char *name)
784 {
785     int len = strlen(name) + 1;
786     uint64_t head_size, name_size;
787 
788     get_note_sizes(s, note, &head_size, &name_size, NULL);
789     head_size = ROUND_UP(head_size, 4);
790 
791     return name_size == len && memcmp(note + head_size, name, len) == 0;
792 }
793 
794 /* write common header, sub header and elf note to vmcore */
795 static void create_header32(DumpState *s, Error **errp)
796 {
797     ERRP_GUARD();
798     DiskDumpHeader32 *dh = NULL;
799     KdumpSubHeader32 *kh = NULL;
800     size_t size;
801     uint32_t block_size;
802     uint32_t sub_hdr_size;
803     uint32_t bitmap_blocks;
804     uint32_t status = 0;
805     uint64_t offset_note;
806 
807     /* write common header, the version of kdump-compressed format is 6th */
808     size = sizeof(DiskDumpHeader32);
809     dh = g_malloc0(size);
810 
811     memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
812     dh->header_version = cpu_to_dump32(s, 6);
813     block_size = s->dump_info.page_size;
814     dh->block_size = cpu_to_dump32(s, block_size);
815     sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
816     sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
817     dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
818     /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
819     dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
820     dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
821     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
822     dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
823     strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
824 
825     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
826         status |= DUMP_DH_COMPRESSED_ZLIB;
827     }
828 #ifdef CONFIG_LZO
829     if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
830         status |= DUMP_DH_COMPRESSED_LZO;
831     }
832 #endif
833 #ifdef CONFIG_SNAPPY
834     if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
835         status |= DUMP_DH_COMPRESSED_SNAPPY;
836     }
837 #endif
838     dh->status = cpu_to_dump32(s, status);
839 
840     if (write_buffer(s->fd, 0, dh, size) < 0) {
841         error_setg(errp, "dump: failed to write disk dump header");
842         goto out;
843     }
844 
845     /* write sub header */
846     size = sizeof(KdumpSubHeader32);
847     kh = g_malloc0(size);
848 
849     /* 64bit max_mapnr_64 */
850     kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
851     kh->phys_base = cpu_to_dump32(s, s->dump_info.phys_base);
852     kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
853 
854     offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
855     if (s->guest_note &&
856         note_name_equal(s, s->guest_note, "VMCOREINFO")) {
857         uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
858 
859         get_note_sizes(s, s->guest_note,
860                        &hsize, &name_size, &size_vmcoreinfo_desc);
861         offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
862             (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
863         kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
864         kh->size_vmcoreinfo = cpu_to_dump32(s, size_vmcoreinfo_desc);
865     }
866 
867     kh->offset_note = cpu_to_dump64(s, offset_note);
868     kh->note_size = cpu_to_dump32(s, s->note_size);
869 
870     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
871                      block_size, kh, size) < 0) {
872         error_setg(errp, "dump: failed to write kdump sub header");
873         goto out;
874     }
875 
876     /* write note */
877     s->note_buf = g_malloc0(s->note_size);
878     s->note_buf_offset = 0;
879 
880     /* use s->note_buf to store notes temporarily */
881     write_elf32_notes(buf_write_note, s, errp);
882     if (*errp) {
883         goto out;
884     }
885     if (write_buffer(s->fd, offset_note, s->note_buf,
886                      s->note_size) < 0) {
887         error_setg(errp, "dump: failed to write notes");
888         goto out;
889     }
890 
891     /* get offset of dump_bitmap */
892     s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
893                              block_size;
894 
895     /* get offset of page */
896     s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
897                      block_size;
898 
899 out:
900     g_free(dh);
901     g_free(kh);
902     g_free(s->note_buf);
903 }
904 
905 /* write common header, sub header and elf note to vmcore */
906 static void create_header64(DumpState *s, Error **errp)
907 {
908     ERRP_GUARD();
909     DiskDumpHeader64 *dh = NULL;
910     KdumpSubHeader64 *kh = NULL;
911     size_t size;
912     uint32_t block_size;
913     uint32_t sub_hdr_size;
914     uint32_t bitmap_blocks;
915     uint32_t status = 0;
916     uint64_t offset_note;
917 
918     /* write common header, the version of kdump-compressed format is 6th */
919     size = sizeof(DiskDumpHeader64);
920     dh = g_malloc0(size);
921 
922     memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
923     dh->header_version = cpu_to_dump32(s, 6);
924     block_size = s->dump_info.page_size;
925     dh->block_size = cpu_to_dump32(s, block_size);
926     sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
927     sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
928     dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
929     /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
930     dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
931     dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
932     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
933     dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
934     strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
935 
936     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
937         status |= DUMP_DH_COMPRESSED_ZLIB;
938     }
939 #ifdef CONFIG_LZO
940     if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
941         status |= DUMP_DH_COMPRESSED_LZO;
942     }
943 #endif
944 #ifdef CONFIG_SNAPPY
945     if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
946         status |= DUMP_DH_COMPRESSED_SNAPPY;
947     }
948 #endif
949     dh->status = cpu_to_dump32(s, status);
950 
951     if (write_buffer(s->fd, 0, dh, size) < 0) {
952         error_setg(errp, "dump: failed to write disk dump header");
953         goto out;
954     }
955 
956     /* write sub header */
957     size = sizeof(KdumpSubHeader64);
958     kh = g_malloc0(size);
959 
960     /* 64bit max_mapnr_64 */
961     kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
962     kh->phys_base = cpu_to_dump64(s, s->dump_info.phys_base);
963     kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
964 
965     offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
966     if (s->guest_note &&
967         note_name_equal(s, s->guest_note, "VMCOREINFO")) {
968         uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
969 
970         get_note_sizes(s, s->guest_note,
971                        &hsize, &name_size, &size_vmcoreinfo_desc);
972         offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
973             (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
974         kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
975         kh->size_vmcoreinfo = cpu_to_dump64(s, size_vmcoreinfo_desc);
976     }
977 
978     kh->offset_note = cpu_to_dump64(s, offset_note);
979     kh->note_size = cpu_to_dump64(s, s->note_size);
980 
981     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
982                      block_size, kh, size) < 0) {
983         error_setg(errp, "dump: failed to write kdump sub header");
984         goto out;
985     }
986 
987     /* write note */
988     s->note_buf = g_malloc0(s->note_size);
989     s->note_buf_offset = 0;
990 
991     /* use s->note_buf to store notes temporarily */
992     write_elf64_notes(buf_write_note, s, errp);
993     if (*errp) {
994         goto out;
995     }
996 
997     if (write_buffer(s->fd, offset_note, s->note_buf,
998                      s->note_size) < 0) {
999         error_setg(errp, "dump: failed to write notes");
1000         goto out;
1001     }
1002 
1003     /* get offset of dump_bitmap */
1004     s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
1005                              block_size;
1006 
1007     /* get offset of page */
1008     s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
1009                      block_size;
1010 
1011 out:
1012     g_free(dh);
1013     g_free(kh);
1014     g_free(s->note_buf);
1015 }
1016 
1017 static void write_dump_header(DumpState *s, Error **errp)
1018 {
1019     if (s->dump_info.d_class == ELFCLASS32) {
1020         create_header32(s, errp);
1021     } else {
1022         create_header64(s, errp);
1023     }
1024 }
1025 
1026 static size_t dump_bitmap_get_bufsize(DumpState *s)
1027 {
1028     return s->dump_info.page_size;
1029 }
1030 
1031 /*
1032  * set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
1033  * rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
1034  * set_dump_bitmap will always leave the recently set bit un-sync. And setting
1035  * (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
1036  * vmcore, ie. synchronizing un-sync bit into vmcore.
1037  */
1038 static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
1039                            uint8_t *buf, DumpState *s)
1040 {
1041     off_t old_offset, new_offset;
1042     off_t offset_bitmap1, offset_bitmap2;
1043     uint32_t byte, bit;
1044     size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
1045     size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
1046 
1047     /* should not set the previous place */
1048     assert(last_pfn <= pfn);
1049 
1050     /*
1051      * if the bit needed to be set is not cached in buf, flush the data in buf
1052      * to vmcore firstly.
1053      * making new_offset be bigger than old_offset can also sync remained data
1054      * into vmcore.
1055      */
1056     old_offset = bitmap_bufsize * (last_pfn / bits_per_buf);
1057     new_offset = bitmap_bufsize * (pfn / bits_per_buf);
1058 
1059     while (old_offset < new_offset) {
1060         /* calculate the offset and write dump_bitmap */
1061         offset_bitmap1 = s->offset_dump_bitmap + old_offset;
1062         if (write_buffer(s->fd, offset_bitmap1, buf,
1063                          bitmap_bufsize) < 0) {
1064             return -1;
1065         }
1066 
1067         /* dump level 1 is chosen, so 1st and 2nd bitmap are same */
1068         offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
1069                          old_offset;
1070         if (write_buffer(s->fd, offset_bitmap2, buf,
1071                          bitmap_bufsize) < 0) {
1072             return -1;
1073         }
1074 
1075         memset(buf, 0, bitmap_bufsize);
1076         old_offset += bitmap_bufsize;
1077     }
1078 
1079     /* get the exact place of the bit in the buf, and set it */
1080     byte = (pfn % bits_per_buf) / CHAR_BIT;
1081     bit = (pfn % bits_per_buf) % CHAR_BIT;
1082     if (value) {
1083         buf[byte] |= 1u << bit;
1084     } else {
1085         buf[byte] &= ~(1u << bit);
1086     }
1087 
1088     return 0;
1089 }
1090 
1091 static uint64_t dump_paddr_to_pfn(DumpState *s, uint64_t addr)
1092 {
1093     int target_page_shift = ctz32(s->dump_info.page_size);
1094 
1095     return (addr >> target_page_shift) - ARCH_PFN_OFFSET;
1096 }
1097 
1098 static uint64_t dump_pfn_to_paddr(DumpState *s, uint64_t pfn)
1099 {
1100     int target_page_shift = ctz32(s->dump_info.page_size);
1101 
1102     return (pfn + ARCH_PFN_OFFSET) << target_page_shift;
1103 }
1104 
1105 /*
1106  * exam every page and return the page frame number and the address of the page.
1107  * bufptr can be NULL. note: the blocks here is supposed to reflect guest-phys
1108  * blocks, so block->target_start and block->target_end should be interal
1109  * multiples of the target page size.
1110  */
1111 static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
1112                           uint8_t **bufptr, DumpState *s)
1113 {
1114     GuestPhysBlock *block = *blockptr;
1115     hwaddr addr, target_page_mask = ~((hwaddr)s->dump_info.page_size - 1);
1116     uint8_t *buf;
1117 
1118     /* block == NULL means the start of the iteration */
1119     if (!block) {
1120         block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
1121         *blockptr = block;
1122         assert((block->target_start & ~target_page_mask) == 0);
1123         assert((block->target_end & ~target_page_mask) == 0);
1124         *pfnptr = dump_paddr_to_pfn(s, block->target_start);
1125         if (bufptr) {
1126             *bufptr = block->host_addr;
1127         }
1128         return true;
1129     }
1130 
1131     *pfnptr = *pfnptr + 1;
1132     addr = dump_pfn_to_paddr(s, *pfnptr);
1133 
1134     if ((addr >= block->target_start) &&
1135         (addr + s->dump_info.page_size <= block->target_end)) {
1136         buf = block->host_addr + (addr - block->target_start);
1137     } else {
1138         /* the next page is in the next block */
1139         block = QTAILQ_NEXT(block, next);
1140         *blockptr = block;
1141         if (!block) {
1142             return false;
1143         }
1144         assert((block->target_start & ~target_page_mask) == 0);
1145         assert((block->target_end & ~target_page_mask) == 0);
1146         *pfnptr = dump_paddr_to_pfn(s, block->target_start);
1147         buf = block->host_addr;
1148     }
1149 
1150     if (bufptr) {
1151         *bufptr = buf;
1152     }
1153 
1154     return true;
1155 }
1156 
1157 static void write_dump_bitmap(DumpState *s, Error **errp)
1158 {
1159     int ret = 0;
1160     uint64_t last_pfn, pfn;
1161     void *dump_bitmap_buf;
1162     size_t num_dumpable;
1163     GuestPhysBlock *block_iter = NULL;
1164     size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
1165     size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
1166 
1167     /* dump_bitmap_buf is used to store dump_bitmap temporarily */
1168     dump_bitmap_buf = g_malloc0(bitmap_bufsize);
1169 
1170     num_dumpable = 0;
1171     last_pfn = 0;
1172 
1173     /*
1174      * exam memory page by page, and set the bit in dump_bitmap corresponded
1175      * to the existing page.
1176      */
1177     while (get_next_page(&block_iter, &pfn, NULL, s)) {
1178         ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
1179         if (ret < 0) {
1180             error_setg(errp, "dump: failed to set dump_bitmap");
1181             goto out;
1182         }
1183 
1184         last_pfn = pfn;
1185         num_dumpable++;
1186     }
1187 
1188     /*
1189      * set_dump_bitmap will always leave the recently set bit un-sync. Here we
1190      * set the remaining bits from last_pfn to the end of the bitmap buffer to
1191      * 0. With those set, the un-sync bit will be synchronized into the vmcore.
1192      */
1193     if (num_dumpable > 0) {
1194         ret = set_dump_bitmap(last_pfn, last_pfn + bits_per_buf, false,
1195                               dump_bitmap_buf, s);
1196         if (ret < 0) {
1197             error_setg(errp, "dump: failed to sync dump_bitmap");
1198             goto out;
1199         }
1200     }
1201 
1202     /* number of dumpable pages that will be dumped later */
1203     s->num_dumpable = num_dumpable;
1204 
1205 out:
1206     g_free(dump_bitmap_buf);
1207 }
1208 
1209 static void prepare_data_cache(DataCache *data_cache, DumpState *s,
1210                                off_t offset)
1211 {
1212     data_cache->fd = s->fd;
1213     data_cache->data_size = 0;
1214     data_cache->buf_size = 4 * dump_bitmap_get_bufsize(s);
1215     data_cache->buf = g_malloc0(data_cache->buf_size);
1216     data_cache->offset = offset;
1217 }
1218 
1219 static int write_cache(DataCache *dc, const void *buf, size_t size,
1220                        bool flag_sync)
1221 {
1222     /*
1223      * dc->buf_size should not be less than size, otherwise dc will never be
1224      * enough
1225      */
1226     assert(size <= dc->buf_size);
1227 
1228     /*
1229      * if flag_sync is set, synchronize data in dc->buf into vmcore.
1230      * otherwise check if the space is enough for caching data in buf, if not,
1231      * write the data in dc->buf to dc->fd and reset dc->buf
1232      */
1233     if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
1234         (flag_sync && dc->data_size > 0)) {
1235         if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) {
1236             return -1;
1237         }
1238 
1239         dc->offset += dc->data_size;
1240         dc->data_size = 0;
1241     }
1242 
1243     if (!flag_sync) {
1244         memcpy(dc->buf + dc->data_size, buf, size);
1245         dc->data_size += size;
1246     }
1247 
1248     return 0;
1249 }
1250 
1251 static void free_data_cache(DataCache *data_cache)
1252 {
1253     g_free(data_cache->buf);
1254 }
1255 
1256 static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
1257 {
1258     switch (flag_compress) {
1259     case DUMP_DH_COMPRESSED_ZLIB:
1260         return compressBound(page_size);
1261 
1262     case DUMP_DH_COMPRESSED_LZO:
1263         /*
1264          * LZO will expand incompressible data by a little amount. Please check
1265          * the following URL to see the expansion calculation:
1266          * http://www.oberhumer.com/opensource/lzo/lzofaq.php
1267          */
1268         return page_size + page_size / 16 + 64 + 3;
1269 
1270 #ifdef CONFIG_SNAPPY
1271     case DUMP_DH_COMPRESSED_SNAPPY:
1272         return snappy_max_compressed_length(page_size);
1273 #endif
1274     }
1275     return 0;
1276 }
1277 
1278 static void write_dump_pages(DumpState *s, Error **errp)
1279 {
1280     int ret = 0;
1281     DataCache page_desc, page_data;
1282     size_t len_buf_out, size_out;
1283 #ifdef CONFIG_LZO
1284     lzo_bytep wrkmem = NULL;
1285 #endif
1286     uint8_t *buf_out = NULL;
1287     off_t offset_desc, offset_data;
1288     PageDescriptor pd, pd_zero;
1289     uint8_t *buf;
1290     GuestPhysBlock *block_iter = NULL;
1291     uint64_t pfn_iter;
1292 
1293     /* get offset of page_desc and page_data in dump file */
1294     offset_desc = s->offset_page;
1295     offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
1296 
1297     prepare_data_cache(&page_desc, s, offset_desc);
1298     prepare_data_cache(&page_data, s, offset_data);
1299 
1300     /* prepare buffer to store compressed data */
1301     len_buf_out = get_len_buf_out(s->dump_info.page_size, s->flag_compress);
1302     assert(len_buf_out != 0);
1303 
1304 #ifdef CONFIG_LZO
1305     wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
1306 #endif
1307 
1308     buf_out = g_malloc(len_buf_out);
1309 
1310     /*
1311      * init zero page's page_desc and page_data, because every zero page
1312      * uses the same page_data
1313      */
1314     pd_zero.size = cpu_to_dump32(s, s->dump_info.page_size);
1315     pd_zero.flags = cpu_to_dump32(s, 0);
1316     pd_zero.offset = cpu_to_dump64(s, offset_data);
1317     pd_zero.page_flags = cpu_to_dump64(s, 0);
1318     buf = g_malloc0(s->dump_info.page_size);
1319     ret = write_cache(&page_data, buf, s->dump_info.page_size, false);
1320     g_free(buf);
1321     if (ret < 0) {
1322         error_setg(errp, "dump: failed to write page data (zero page)");
1323         goto out;
1324     }
1325 
1326     offset_data += s->dump_info.page_size;
1327 
1328     /*
1329      * dump memory to vmcore page by page. zero page will all be resided in the
1330      * first page of page section
1331      */
1332     while (get_next_page(&block_iter, &pfn_iter, &buf, s)) {
1333         /* check zero page */
1334         if (buffer_is_zero(buf, s->dump_info.page_size)) {
1335             ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
1336                               false);
1337             if (ret < 0) {
1338                 error_setg(errp, "dump: failed to write page desc");
1339                 goto out;
1340             }
1341         } else {
1342             /*
1343              * not zero page, then:
1344              * 1. compress the page
1345              * 2. write the compressed page into the cache of page_data
1346              * 3. get page desc of the compressed page and write it into the
1347              *    cache of page_desc
1348              *
1349              * only one compression format will be used here, for
1350              * s->flag_compress is set. But when compression fails to work,
1351              * we fall back to save in plaintext.
1352              */
1353              size_out = len_buf_out;
1354              if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
1355                     (compress2(buf_out, (uLongf *)&size_out, buf,
1356                                s->dump_info.page_size, Z_BEST_SPEED) == Z_OK) &&
1357                     (size_out < s->dump_info.page_size)) {
1358                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_ZLIB);
1359                 pd.size  = cpu_to_dump32(s, size_out);
1360 
1361                 ret = write_cache(&page_data, buf_out, size_out, false);
1362                 if (ret < 0) {
1363                     error_setg(errp, "dump: failed to write page data");
1364                     goto out;
1365                 }
1366 #ifdef CONFIG_LZO
1367             } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
1368                     (lzo1x_1_compress(buf, s->dump_info.page_size, buf_out,
1369                     (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
1370                     (size_out < s->dump_info.page_size)) {
1371                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_LZO);
1372                 pd.size  = cpu_to_dump32(s, size_out);
1373 
1374                 ret = write_cache(&page_data, buf_out, size_out, false);
1375                 if (ret < 0) {
1376                     error_setg(errp, "dump: failed to write page data");
1377                     goto out;
1378                 }
1379 #endif
1380 #ifdef CONFIG_SNAPPY
1381             } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
1382                     (snappy_compress((char *)buf, s->dump_info.page_size,
1383                     (char *)buf_out, &size_out) == SNAPPY_OK) &&
1384                     (size_out < s->dump_info.page_size)) {
1385                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_SNAPPY);
1386                 pd.size  = cpu_to_dump32(s, size_out);
1387 
1388                 ret = write_cache(&page_data, buf_out, size_out, false);
1389                 if (ret < 0) {
1390                     error_setg(errp, "dump: failed to write page data");
1391                     goto out;
1392                 }
1393 #endif
1394             } else {
1395                 /*
1396                  * fall back to save in plaintext, size_out should be
1397                  * assigned the target's page size
1398                  */
1399                 pd.flags = cpu_to_dump32(s, 0);
1400                 size_out = s->dump_info.page_size;
1401                 pd.size = cpu_to_dump32(s, size_out);
1402 
1403                 ret = write_cache(&page_data, buf,
1404                                   s->dump_info.page_size, false);
1405                 if (ret < 0) {
1406                     error_setg(errp, "dump: failed to write page data");
1407                     goto out;
1408                 }
1409             }
1410 
1411             /* get and write page desc here */
1412             pd.page_flags = cpu_to_dump64(s, 0);
1413             pd.offset = cpu_to_dump64(s, offset_data);
1414             offset_data += size_out;
1415 
1416             ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
1417             if (ret < 0) {
1418                 error_setg(errp, "dump: failed to write page desc");
1419                 goto out;
1420             }
1421         }
1422         s->written_size += s->dump_info.page_size;
1423     }
1424 
1425     ret = write_cache(&page_desc, NULL, 0, true);
1426     if (ret < 0) {
1427         error_setg(errp, "dump: failed to sync cache for page_desc");
1428         goto out;
1429     }
1430     ret = write_cache(&page_data, NULL, 0, true);
1431     if (ret < 0) {
1432         error_setg(errp, "dump: failed to sync cache for page_data");
1433         goto out;
1434     }
1435 
1436 out:
1437     free_data_cache(&page_desc);
1438     free_data_cache(&page_data);
1439 
1440 #ifdef CONFIG_LZO
1441     g_free(wrkmem);
1442 #endif
1443 
1444     g_free(buf_out);
1445 }
1446 
1447 static void create_kdump_vmcore(DumpState *s, Error **errp)
1448 {
1449     ERRP_GUARD();
1450     int ret;
1451 
1452     /*
1453      * the kdump-compressed format is:
1454      *                                               File offset
1455      *  +------------------------------------------+ 0x0
1456      *  |    main header (struct disk_dump_header) |
1457      *  |------------------------------------------+ block 1
1458      *  |    sub header (struct kdump_sub_header)  |
1459      *  |------------------------------------------+ block 2
1460      *  |            1st-dump_bitmap               |
1461      *  |------------------------------------------+ block 2 + X blocks
1462      *  |            2nd-dump_bitmap               | (aligned by block)
1463      *  |------------------------------------------+ block 2 + 2 * X blocks
1464      *  |  page desc for pfn 0 (struct page_desc)  | (aligned by block)
1465      *  |  page desc for pfn 1 (struct page_desc)  |
1466      *  |                    :                     |
1467      *  |------------------------------------------| (not aligned by block)
1468      *  |         page data (pfn 0)                |
1469      *  |         page data (pfn 1)                |
1470      *  |                    :                     |
1471      *  +------------------------------------------+
1472      */
1473 
1474     ret = write_start_flat_header(s->fd);
1475     if (ret < 0) {
1476         error_setg(errp, "dump: failed to write start flat header");
1477         return;
1478     }
1479 
1480     write_dump_header(s, errp);
1481     if (*errp) {
1482         return;
1483     }
1484 
1485     write_dump_bitmap(s, errp);
1486     if (*errp) {
1487         return;
1488     }
1489 
1490     write_dump_pages(s, errp);
1491     if (*errp) {
1492         return;
1493     }
1494 
1495     ret = write_end_flat_header(s->fd);
1496     if (ret < 0) {
1497         error_setg(errp, "dump: failed to write end flat header");
1498         return;
1499     }
1500 }
1501 
1502 static ram_addr_t get_start_block(DumpState *s)
1503 {
1504     GuestPhysBlock *block;
1505 
1506     if (!s->has_filter) {
1507         s->next_block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
1508         return 0;
1509     }
1510 
1511     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1512         if (block->target_start >= s->begin + s->length ||
1513             block->target_end <= s->begin) {
1514             /* This block is out of the range */
1515             continue;
1516         }
1517 
1518         s->next_block = block;
1519         if (s->begin > block->target_start) {
1520             s->start = s->begin - block->target_start;
1521         } else {
1522             s->start = 0;
1523         }
1524         return s->start;
1525     }
1526 
1527     return -1;
1528 }
1529 
1530 static void get_max_mapnr(DumpState *s)
1531 {
1532     GuestPhysBlock *last_block;
1533 
1534     last_block = QTAILQ_LAST(&s->guest_phys_blocks.head);
1535     s->max_mapnr = dump_paddr_to_pfn(s, last_block->target_end);
1536 }
1537 
1538 static DumpState dump_state_global = { .status = DUMP_STATUS_NONE };
1539 
1540 static void dump_state_prepare(DumpState *s)
1541 {
1542     /* zero the struct, setting status to active */
1543     *s = (DumpState) { .status = DUMP_STATUS_ACTIVE };
1544 }
1545 
1546 bool qemu_system_dump_in_progress(void)
1547 {
1548     DumpState *state = &dump_state_global;
1549     return (qatomic_read(&state->status) == DUMP_STATUS_ACTIVE);
1550 }
1551 
1552 /* calculate total size of memory to be dumped (taking filter into
1553  * acoount.) */
1554 static int64_t dump_calculate_size(DumpState *s)
1555 {
1556     GuestPhysBlock *block;
1557     int64_t size = 0, total = 0, left = 0, right = 0;
1558 
1559     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1560         if (s->has_filter) {
1561             /* calculate the overlapped region. */
1562             left = MAX(s->begin, block->target_start);
1563             right = MIN(s->begin + s->length, block->target_end);
1564             size = right - left;
1565             size = size > 0 ? size : 0;
1566         } else {
1567             /* count the whole region in */
1568             size = (block->target_end - block->target_start);
1569         }
1570         total += size;
1571     }
1572 
1573     return total;
1574 }
1575 
1576 static void vmcoreinfo_update_phys_base(DumpState *s)
1577 {
1578     uint64_t size, note_head_size, name_size, phys_base;
1579     char **lines;
1580     uint8_t *vmci;
1581     size_t i;
1582 
1583     if (!note_name_equal(s, s->guest_note, "VMCOREINFO")) {
1584         return;
1585     }
1586 
1587     get_note_sizes(s, s->guest_note, &note_head_size, &name_size, &size);
1588     note_head_size = ROUND_UP(note_head_size, 4);
1589 
1590     vmci = s->guest_note + note_head_size + ROUND_UP(name_size, 4);
1591     *(vmci + size) = '\0';
1592 
1593     lines = g_strsplit((char *)vmci, "\n", -1);
1594     for (i = 0; lines[i]; i++) {
1595         const char *prefix = NULL;
1596 
1597         if (s->dump_info.d_machine == EM_X86_64) {
1598             prefix = "NUMBER(phys_base)=";
1599         } else if (s->dump_info.d_machine == EM_AARCH64) {
1600             prefix = "NUMBER(PHYS_OFFSET)=";
1601         }
1602 
1603         if (prefix && g_str_has_prefix(lines[i], prefix)) {
1604             if (qemu_strtou64(lines[i] + strlen(prefix), NULL, 16,
1605                               &phys_base) < 0) {
1606                 warn_report("Failed to read %s", prefix);
1607             } else {
1608                 s->dump_info.phys_base = phys_base;
1609             }
1610             break;
1611         }
1612     }
1613 
1614     g_strfreev(lines);
1615 }
1616 
1617 static void dump_init(DumpState *s, int fd, bool has_format,
1618                       DumpGuestMemoryFormat format, bool paging, bool has_filter,
1619                       int64_t begin, int64_t length, Error **errp)
1620 {
1621     ERRP_GUARD();
1622     VMCoreInfoState *vmci = vmcoreinfo_find();
1623     CPUState *cpu;
1624     int nr_cpus;
1625     int ret;
1626 
1627     s->has_format = has_format;
1628     s->format = format;
1629     s->written_size = 0;
1630 
1631     /* kdump-compressed is conflict with paging and filter */
1632     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1633         assert(!paging && !has_filter);
1634     }
1635 
1636     if (runstate_is_running()) {
1637         vm_stop(RUN_STATE_SAVE_VM);
1638         s->resume = true;
1639     } else {
1640         s->resume = false;
1641     }
1642 
1643     /* If we use KVM, we should synchronize the registers before we get dump
1644      * info or physmap info.
1645      */
1646     cpu_synchronize_all_states();
1647     nr_cpus = 0;
1648     CPU_FOREACH(cpu) {
1649         nr_cpus++;
1650     }
1651 
1652     s->fd = fd;
1653     s->has_filter = has_filter;
1654     s->begin = begin;
1655     s->length = length;
1656 
1657     memory_mapping_list_init(&s->list);
1658 
1659     guest_phys_blocks_init(&s->guest_phys_blocks);
1660     guest_phys_blocks_append(&s->guest_phys_blocks);
1661     s->total_size = dump_calculate_size(s);
1662 #ifdef DEBUG_DUMP_GUEST_MEMORY
1663     fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
1664 #endif
1665 
1666     /* it does not make sense to dump non-existent memory */
1667     if (!s->total_size) {
1668         error_setg(errp, "dump: no guest memory to dump");
1669         goto cleanup;
1670     }
1671 
1672     s->start = get_start_block(s);
1673     if (s->start == -1) {
1674         error_setg(errp, QERR_INVALID_PARAMETER, "begin");
1675         goto cleanup;
1676     }
1677 
1678     /* get dump info: endian, class and architecture.
1679      * If the target architecture is not supported, cpu_get_dump_info() will
1680      * return -1.
1681      */
1682     ret = cpu_get_dump_info(&s->dump_info, &s->guest_phys_blocks);
1683     if (ret < 0) {
1684         error_setg(errp, QERR_UNSUPPORTED);
1685         goto cleanup;
1686     }
1687 
1688     if (!s->dump_info.page_size) {
1689         s->dump_info.page_size = TARGET_PAGE_SIZE;
1690     }
1691 
1692     s->note_size = cpu_get_note_size(s->dump_info.d_class,
1693                                      s->dump_info.d_machine, nr_cpus);
1694     if (s->note_size < 0) {
1695         error_setg(errp, QERR_UNSUPPORTED);
1696         goto cleanup;
1697     }
1698 
1699     /*
1700      * The goal of this block is to (a) update the previously guessed
1701      * phys_base, (b) copy the guest note out of the guest.
1702      * Failure to do so is not fatal for dumping.
1703      */
1704     if (vmci) {
1705         uint64_t addr, note_head_size, name_size, desc_size;
1706         uint32_t size;
1707         uint16_t format;
1708 
1709         note_head_size = s->dump_info.d_class == ELFCLASS32 ?
1710             sizeof(Elf32_Nhdr) : sizeof(Elf64_Nhdr);
1711 
1712         format = le16_to_cpu(vmci->vmcoreinfo.guest_format);
1713         size = le32_to_cpu(vmci->vmcoreinfo.size);
1714         addr = le64_to_cpu(vmci->vmcoreinfo.paddr);
1715         if (!vmci->has_vmcoreinfo) {
1716             warn_report("guest note is not present");
1717         } else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) {
1718             warn_report("guest note size is invalid: %" PRIu32, size);
1719         } else if (format != FW_CFG_VMCOREINFO_FORMAT_ELF) {
1720             warn_report("guest note format is unsupported: %" PRIu16, format);
1721         } else {
1722             s->guest_note = g_malloc(size + 1); /* +1 for adding \0 */
1723             cpu_physical_memory_read(addr, s->guest_note, size);
1724 
1725             get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_size);
1726             s->guest_note_size = ELF_NOTE_SIZE(note_head_size, name_size,
1727                                                desc_size);
1728             if (name_size > MAX_GUEST_NOTE_SIZE ||
1729                 desc_size > MAX_GUEST_NOTE_SIZE ||
1730                 s->guest_note_size > size) {
1731                 warn_report("Invalid guest note header");
1732                 g_free(s->guest_note);
1733                 s->guest_note = NULL;
1734             } else {
1735                 vmcoreinfo_update_phys_base(s);
1736                 s->note_size += s->guest_note_size;
1737             }
1738         }
1739     }
1740 
1741     /* get memory mapping */
1742     if (paging) {
1743         qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, errp);
1744         if (*errp) {
1745             goto cleanup;
1746         }
1747     } else {
1748         qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
1749     }
1750 
1751     s->nr_cpus = nr_cpus;
1752 
1753     get_max_mapnr(s);
1754 
1755     uint64_t tmp;
1756     tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT),
1757                        s->dump_info.page_size);
1758     s->len_dump_bitmap = tmp * s->dump_info.page_size;
1759 
1760     /* init for kdump-compressed format */
1761     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1762         switch (format) {
1763         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
1764             s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
1765             break;
1766 
1767         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
1768 #ifdef CONFIG_LZO
1769             if (lzo_init() != LZO_E_OK) {
1770                 error_setg(errp, "failed to initialize the LZO library");
1771                 goto cleanup;
1772             }
1773 #endif
1774             s->flag_compress = DUMP_DH_COMPRESSED_LZO;
1775             break;
1776 
1777         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
1778             s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
1779             break;
1780 
1781         default:
1782             s->flag_compress = 0;
1783         }
1784 
1785         return;
1786     }
1787 
1788     if (s->has_filter) {
1789         memory_mapping_filter(&s->list, s->begin, s->length);
1790     }
1791 
1792     /*
1793      * calculate phdr_num
1794      *
1795      * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
1796      */
1797     s->phdr_num = 1; /* PT_NOTE */
1798     if (s->list.num < UINT16_MAX - 2) {
1799         s->shdr_num = 0;
1800         s->phdr_num += s->list.num;
1801     } else {
1802         /* sh_info of section 0 holds the real number of phdrs */
1803         s->shdr_num = 1;
1804 
1805         /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
1806         if (s->list.num <= UINT32_MAX - 1) {
1807             s->phdr_num += s->list.num;
1808         } else {
1809             s->phdr_num = UINT32_MAX;
1810         }
1811     }
1812 
1813     if (s->dump_info.d_class == ELFCLASS64) {
1814         s->phdr_offset = sizeof(Elf64_Ehdr);
1815         s->shdr_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
1816         s->note_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
1817         s->memory_offset = s->note_offset + s->note_size;
1818     } else {
1819 
1820         s->phdr_offset = sizeof(Elf32_Ehdr);
1821         s->shdr_offset = s->phdr_offset + sizeof(Elf32_Phdr) * s->phdr_num;
1822         s->note_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
1823         s->memory_offset = s->note_offset + s->note_size;
1824     }
1825 
1826     return;
1827 
1828 cleanup:
1829     dump_cleanup(s);
1830 }
1831 
1832 /* this operation might be time consuming. */
1833 static void dump_process(DumpState *s, Error **errp)
1834 {
1835     ERRP_GUARD();
1836     DumpQueryResult *result = NULL;
1837 
1838     if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
1839 #ifdef TARGET_X86_64
1840         create_win_dump(s, errp);
1841 #endif
1842     } else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1843         create_kdump_vmcore(s, errp);
1844     } else {
1845         create_vmcore(s, errp);
1846     }
1847 
1848     /* make sure status is written after written_size updates */
1849     smp_wmb();
1850     qatomic_set(&s->status,
1851                (*errp ? DUMP_STATUS_FAILED : DUMP_STATUS_COMPLETED));
1852 
1853     /* send DUMP_COMPLETED message (unconditionally) */
1854     result = qmp_query_dump(NULL);
1855     /* should never fail */
1856     assert(result);
1857     qapi_event_send_dump_completed(result, !!*errp, (*errp ?
1858                                                      error_get_pretty(*errp) : NULL));
1859     qapi_free_DumpQueryResult(result);
1860 
1861     dump_cleanup(s);
1862 }
1863 
1864 static void *dump_thread(void *data)
1865 {
1866     DumpState *s = (DumpState *)data;
1867     dump_process(s, NULL);
1868     return NULL;
1869 }
1870 
1871 DumpQueryResult *qmp_query_dump(Error **errp)
1872 {
1873     DumpQueryResult *result = g_new(DumpQueryResult, 1);
1874     DumpState *state = &dump_state_global;
1875     result->status = qatomic_read(&state->status);
1876     /* make sure we are reading status and written_size in order */
1877     smp_rmb();
1878     result->completed = state->written_size;
1879     result->total = state->total_size;
1880     return result;
1881 }
1882 
1883 void qmp_dump_guest_memory(bool paging, const char *file,
1884                            bool has_detach, bool detach,
1885                            bool has_begin, int64_t begin, bool has_length,
1886                            int64_t length, bool has_format,
1887                            DumpGuestMemoryFormat format, Error **errp)
1888 {
1889     ERRP_GUARD();
1890     const char *p;
1891     int fd = -1;
1892     DumpState *s;
1893     bool detach_p = false;
1894 
1895     if (runstate_check(RUN_STATE_INMIGRATE)) {
1896         error_setg(errp, "Dump not allowed during incoming migration.");
1897         return;
1898     }
1899 
1900     /* if there is a dump in background, we should wait until the dump
1901      * finished */
1902     if (qemu_system_dump_in_progress()) {
1903         error_setg(errp, "There is a dump in process, please wait.");
1904         return;
1905     }
1906 
1907     /*
1908      * kdump-compressed format need the whole memory dumped, so paging or
1909      * filter is not supported here.
1910      */
1911     if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
1912         (paging || has_begin || has_length)) {
1913         error_setg(errp, "kdump-compressed format doesn't support paging or "
1914                          "filter");
1915         return;
1916     }
1917     if (has_begin && !has_length) {
1918         error_setg(errp, QERR_MISSING_PARAMETER, "length");
1919         return;
1920     }
1921     if (!has_begin && has_length) {
1922         error_setg(errp, QERR_MISSING_PARAMETER, "begin");
1923         return;
1924     }
1925     if (has_detach) {
1926         detach_p = detach;
1927     }
1928 
1929     /* check whether lzo/snappy is supported */
1930 #ifndef CONFIG_LZO
1931     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
1932         error_setg(errp, "kdump-lzo is not available now");
1933         return;
1934     }
1935 #endif
1936 
1937 #ifndef CONFIG_SNAPPY
1938     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
1939         error_setg(errp, "kdump-snappy is not available now");
1940         return;
1941     }
1942 #endif
1943 
1944 #ifndef TARGET_X86_64
1945     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
1946         error_setg(errp, "Windows dump is only available for x86-64");
1947         return;
1948     }
1949 #endif
1950 
1951 #if !defined(WIN32)
1952     if (strstart(file, "fd:", &p)) {
1953         fd = monitor_get_fd(monitor_cur(), p, errp);
1954         if (fd == -1) {
1955             return;
1956         }
1957     }
1958 #endif
1959 
1960     if  (strstart(file, "file:", &p)) {
1961         fd = qemu_open_old(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
1962         if (fd < 0) {
1963             error_setg_file_open(errp, errno, p);
1964             return;
1965         }
1966     }
1967 
1968     if (fd == -1) {
1969         error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
1970         return;
1971     }
1972 
1973     if (!dump_migration_blocker) {
1974         error_setg(&dump_migration_blocker,
1975                    "Live migration disabled: dump-guest-memory in progress");
1976     }
1977 
1978     /*
1979      * Allows even for -only-migratable, but forbid migration during the
1980      * process of dump guest memory.
1981      */
1982     if (migrate_add_blocker_internal(dump_migration_blocker, errp)) {
1983         /* Remember to release the fd before passing it over to dump state */
1984         close(fd);
1985         return;
1986     }
1987 
1988     s = &dump_state_global;
1989     dump_state_prepare(s);
1990 
1991     dump_init(s, fd, has_format, format, paging, has_begin,
1992               begin, length, errp);
1993     if (*errp) {
1994         qatomic_set(&s->status, DUMP_STATUS_FAILED);
1995         return;
1996     }
1997 
1998     if (detach_p) {
1999         /* detached dump */
2000         s->detached = true;
2001         qemu_thread_create(&s->dump_thread, "dump_thread", dump_thread,
2002                            s, QEMU_THREAD_DETACHED);
2003     } else {
2004         /* sync dump */
2005         dump_process(s, errp);
2006     }
2007 }
2008 
2009 DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
2010 {
2011     DumpGuestMemoryCapability *cap =
2012                                   g_new0(DumpGuestMemoryCapability, 1);
2013     DumpGuestMemoryFormatList **tail = &cap->formats;
2014 
2015     /* elf is always available */
2016     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_ELF);
2017 
2018     /* kdump-zlib is always available */
2019     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB);
2020 
2021     /* add new item if kdump-lzo is available */
2022 #ifdef CONFIG_LZO
2023     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO);
2024 #endif
2025 
2026     /* add new item if kdump-snappy is available */
2027 #ifdef CONFIG_SNAPPY
2028     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
2029 #endif
2030 
2031     /* Windows dump is available only if target is x86_64 */
2032 #ifdef TARGET_X86_64
2033     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
2034 #endif
2035 
2036     return cap;
2037 }
2038