xref: /openbmc/qemu/dump/dump.c (revision 6c187695)
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 static inline bool dump_is_64bit(DumpState *s)
58 {
59     return s->dump_info.d_class == ELFCLASS64;
60 }
61 
62 static inline bool dump_has_filter(DumpState *s)
63 {
64     return s->filter_area_length > 0;
65 }
66 
67 uint16_t cpu_to_dump16(DumpState *s, uint16_t val)
68 {
69     if (s->dump_info.d_endian == ELFDATA2LSB) {
70         val = cpu_to_le16(val);
71     } else {
72         val = cpu_to_be16(val);
73     }
74 
75     return val;
76 }
77 
78 uint32_t cpu_to_dump32(DumpState *s, uint32_t val)
79 {
80     if (s->dump_info.d_endian == ELFDATA2LSB) {
81         val = cpu_to_le32(val);
82     } else {
83         val = cpu_to_be32(val);
84     }
85 
86     return val;
87 }
88 
89 uint64_t cpu_to_dump64(DumpState *s, uint64_t val)
90 {
91     if (s->dump_info.d_endian == ELFDATA2LSB) {
92         val = cpu_to_le64(val);
93     } else {
94         val = cpu_to_be64(val);
95     }
96 
97     return val;
98 }
99 
100 static int dump_cleanup(DumpState *s)
101 {
102     guest_phys_blocks_free(&s->guest_phys_blocks);
103     memory_mapping_list_free(&s->list);
104     close(s->fd);
105     g_free(s->guest_note);
106     s->guest_note = NULL;
107     if (s->resume) {
108         if (s->detached) {
109             qemu_mutex_lock_iothread();
110         }
111         vm_start();
112         if (s->detached) {
113             qemu_mutex_unlock_iothread();
114         }
115     }
116     migrate_del_blocker(dump_migration_blocker);
117 
118     return 0;
119 }
120 
121 static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
122 {
123     DumpState *s = opaque;
124     size_t written_size;
125 
126     written_size = qemu_write_full(s->fd, buf, size);
127     if (written_size != size) {
128         return -errno;
129     }
130 
131     return 0;
132 }
133 
134 static void prepare_elf64_header(DumpState *s, Elf64_Ehdr *elf_header)
135 {
136     /*
137      * phnum in the elf header is 16 bit, if we have more segments we
138      * set phnum to PN_XNUM and write the real number of segments to a
139      * special section.
140      */
141     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
142 
143     memset(elf_header, 0, sizeof(Elf64_Ehdr));
144     memcpy(elf_header, ELFMAG, SELFMAG);
145     elf_header->e_ident[EI_CLASS] = ELFCLASS64;
146     elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
147     elf_header->e_ident[EI_VERSION] = EV_CURRENT;
148     elf_header->e_type = cpu_to_dump16(s, ET_CORE);
149     elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
150     elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
151     elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
152     elf_header->e_phoff = cpu_to_dump64(s, s->phdr_offset);
153     elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
154     elf_header->e_phnum = cpu_to_dump16(s, phnum);
155     if (s->shdr_num) {
156         elf_header->e_shoff = cpu_to_dump64(s, s->shdr_offset);
157         elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
158         elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
159     }
160 }
161 
162 static void prepare_elf32_header(DumpState *s, Elf32_Ehdr *elf_header)
163 {
164     /*
165      * phnum in the elf header is 16 bit, if we have more segments we
166      * set phnum to PN_XNUM and write the real number of segments to a
167      * special section.
168      */
169     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
170 
171     memset(elf_header, 0, sizeof(Elf32_Ehdr));
172     memcpy(elf_header, ELFMAG, SELFMAG);
173     elf_header->e_ident[EI_CLASS] = ELFCLASS32;
174     elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
175     elf_header->e_ident[EI_VERSION] = EV_CURRENT;
176     elf_header->e_type = cpu_to_dump16(s, ET_CORE);
177     elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
178     elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
179     elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
180     elf_header->e_phoff = cpu_to_dump32(s, s->phdr_offset);
181     elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
182     elf_header->e_phnum = cpu_to_dump16(s, phnum);
183     if (s->shdr_num) {
184         elf_header->e_shoff = cpu_to_dump32(s, s->shdr_offset);
185         elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
186         elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
187     }
188 }
189 
190 static void write_elf_header(DumpState *s, Error **errp)
191 {
192     Elf32_Ehdr elf32_header;
193     Elf64_Ehdr elf64_header;
194     size_t header_size;
195     void *header_ptr;
196     int ret;
197 
198     if (dump_is_64bit(s)) {
199         prepare_elf64_header(s, &elf64_header);
200         header_size = sizeof(elf64_header);
201         header_ptr = &elf64_header;
202     } else {
203         prepare_elf32_header(s, &elf32_header);
204         header_size = sizeof(elf32_header);
205         header_ptr = &elf32_header;
206     }
207 
208     ret = fd_write_vmcore(header_ptr, header_size, s);
209     if (ret < 0) {
210         error_setg_errno(errp, -ret, "dump: failed to write elf header");
211     }
212 }
213 
214 static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
215                              int phdr_index, hwaddr offset,
216                              hwaddr filesz, Error **errp)
217 {
218     Elf64_Phdr phdr;
219     int ret;
220 
221     memset(&phdr, 0, sizeof(Elf64_Phdr));
222     phdr.p_type = cpu_to_dump32(s, PT_LOAD);
223     phdr.p_offset = cpu_to_dump64(s, offset);
224     phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
225     phdr.p_filesz = cpu_to_dump64(s, filesz);
226     phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
227     phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
228 
229     assert(memory_mapping->length >= filesz);
230 
231     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
232     if (ret < 0) {
233         error_setg_errno(errp, -ret,
234                          "dump: failed to write program header table");
235     }
236 }
237 
238 static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
239                              int phdr_index, hwaddr offset,
240                              hwaddr filesz, Error **errp)
241 {
242     Elf32_Phdr phdr;
243     int ret;
244 
245     memset(&phdr, 0, sizeof(Elf32_Phdr));
246     phdr.p_type = cpu_to_dump32(s, PT_LOAD);
247     phdr.p_offset = cpu_to_dump32(s, offset);
248     phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
249     phdr.p_filesz = cpu_to_dump32(s, filesz);
250     phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
251     phdr.p_vaddr =
252         cpu_to_dump32(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
253 
254     assert(memory_mapping->length >= filesz);
255 
256     ret = fd_write_vmcore(&phdr, sizeof(Elf32_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 void prepare_elf64_phdr_note(DumpState *s, Elf64_Phdr *phdr)
264 {
265     memset(phdr, 0, sizeof(*phdr));
266     phdr->p_type = cpu_to_dump32(s, PT_NOTE);
267     phdr->p_offset = cpu_to_dump64(s, s->note_offset);
268     phdr->p_paddr = 0;
269     phdr->p_filesz = cpu_to_dump64(s, s->note_size);
270     phdr->p_memsz = cpu_to_dump64(s, s->note_size);
271     phdr->p_vaddr = 0;
272 }
273 
274 static inline int cpu_index(CPUState *cpu)
275 {
276     return cpu->cpu_index + 1;
277 }
278 
279 static void write_guest_note(WriteCoreDumpFunction f, DumpState *s,
280                              Error **errp)
281 {
282     int ret;
283 
284     if (s->guest_note) {
285         ret = f(s->guest_note, s->guest_note_size, s);
286         if (ret < 0) {
287             error_setg(errp, "dump: failed to write guest note");
288         }
289     }
290 }
291 
292 static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
293                               Error **errp)
294 {
295     CPUState *cpu;
296     int ret;
297     int id;
298 
299     CPU_FOREACH(cpu) {
300         id = cpu_index(cpu);
301         ret = cpu_write_elf64_note(f, cpu, id, s);
302         if (ret < 0) {
303             error_setg(errp, "dump: failed to write elf notes");
304             return;
305         }
306     }
307 
308     CPU_FOREACH(cpu) {
309         ret = cpu_write_elf64_qemunote(f, cpu, s);
310         if (ret < 0) {
311             error_setg(errp, "dump: failed to write CPU status");
312             return;
313         }
314     }
315 
316     write_guest_note(f, s, errp);
317 }
318 
319 static void prepare_elf32_phdr_note(DumpState *s, Elf32_Phdr *phdr)
320 {
321     memset(phdr, 0, sizeof(*phdr));
322     phdr->p_type = cpu_to_dump32(s, PT_NOTE);
323     phdr->p_offset = cpu_to_dump32(s, s->note_offset);
324     phdr->p_paddr = 0;
325     phdr->p_filesz = cpu_to_dump32(s, s->note_size);
326     phdr->p_memsz = cpu_to_dump32(s, s->note_size);
327     phdr->p_vaddr = 0;
328 }
329 
330 static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
331                               Error **errp)
332 {
333     CPUState *cpu;
334     int ret;
335     int id;
336 
337     CPU_FOREACH(cpu) {
338         id = cpu_index(cpu);
339         ret = cpu_write_elf32_note(f, cpu, id, s);
340         if (ret < 0) {
341             error_setg(errp, "dump: failed to write elf notes");
342             return;
343         }
344     }
345 
346     CPU_FOREACH(cpu) {
347         ret = cpu_write_elf32_qemunote(f, cpu, s);
348         if (ret < 0) {
349             error_setg(errp, "dump: failed to write CPU status");
350             return;
351         }
352     }
353 
354     write_guest_note(f, s, errp);
355 }
356 
357 static void write_elf_phdr_note(DumpState *s, Error **errp)
358 {
359     ERRP_GUARD();
360     Elf32_Phdr phdr32;
361     Elf64_Phdr phdr64;
362     void *phdr;
363     size_t size;
364     int ret;
365 
366     if (dump_is_64bit(s)) {
367         prepare_elf64_phdr_note(s, &phdr64);
368         size = sizeof(phdr64);
369         phdr = &phdr64;
370     } else {
371         prepare_elf32_phdr_note(s, &phdr32);
372         size = sizeof(phdr32);
373         phdr = &phdr32;
374     }
375 
376     ret = fd_write_vmcore(phdr, size, s);
377     if (ret < 0) {
378         error_setg_errno(errp, -ret,
379                          "dump: failed to write program header table");
380     }
381 }
382 
383 static void write_elf_section(DumpState *s, int type, Error **errp)
384 {
385     Elf32_Shdr shdr32;
386     Elf64_Shdr shdr64;
387     int shdr_size;
388     void *shdr;
389     int ret;
390 
391     if (type == 0) {
392         shdr_size = sizeof(Elf32_Shdr);
393         memset(&shdr32, 0, shdr_size);
394         shdr32.sh_info = cpu_to_dump32(s, s->phdr_num);
395         shdr = &shdr32;
396     } else {
397         shdr_size = sizeof(Elf64_Shdr);
398         memset(&shdr64, 0, shdr_size);
399         shdr64.sh_info = cpu_to_dump32(s, s->phdr_num);
400         shdr = &shdr64;
401     }
402 
403     ret = fd_write_vmcore(shdr, shdr_size, s);
404     if (ret < 0) {
405         error_setg_errno(errp, -ret,
406                          "dump: failed to write section header table");
407     }
408 }
409 
410 static void write_data(DumpState *s, void *buf, int length, Error **errp)
411 {
412     int ret;
413 
414     ret = fd_write_vmcore(buf, length, s);
415     if (ret < 0) {
416         error_setg_errno(errp, -ret, "dump: failed to save memory");
417     } else {
418         s->written_size += length;
419     }
420 }
421 
422 /* write the memory to vmcore. 1 page per I/O. */
423 static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
424                          int64_t size, Error **errp)
425 {
426     ERRP_GUARD();
427     int64_t i;
428 
429     for (i = 0; i < size / s->dump_info.page_size; i++) {
430         write_data(s, block->host_addr + start + i * s->dump_info.page_size,
431                    s->dump_info.page_size, errp);
432         if (*errp) {
433             return;
434         }
435     }
436 
437     if ((size % s->dump_info.page_size) != 0) {
438         write_data(s, block->host_addr + start + i * s->dump_info.page_size,
439                    size % s->dump_info.page_size, errp);
440         if (*errp) {
441             return;
442         }
443     }
444 }
445 
446 /* get the memory's offset and size in the vmcore */
447 static void get_offset_range(hwaddr phys_addr,
448                              ram_addr_t mapping_length,
449                              DumpState *s,
450                              hwaddr *p_offset,
451                              hwaddr *p_filesz)
452 {
453     GuestPhysBlock *block;
454     hwaddr offset = s->memory_offset;
455     int64_t size_in_block, start;
456 
457     /* When the memory is not stored into vmcore, offset will be -1 */
458     *p_offset = -1;
459     *p_filesz = 0;
460 
461     if (dump_has_filter(s)) {
462         if (phys_addr < s->filter_area_begin ||
463             phys_addr >= s->filter_area_begin + s->filter_area_length) {
464             return;
465         }
466     }
467 
468     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
469         if (dump_has_filter(s)) {
470             if (block->target_start >= s->filter_area_begin + s->filter_area_length ||
471                 block->target_end <= s->filter_area_begin) {
472                 /* This block is out of the range */
473                 continue;
474             }
475 
476             if (s->filter_area_begin <= block->target_start) {
477                 start = block->target_start;
478             } else {
479                 start = s->filter_area_begin;
480             }
481 
482             size_in_block = block->target_end - start;
483             if (s->filter_area_begin + s->filter_area_length < block->target_end) {
484                 size_in_block -= block->target_end - (s->filter_area_begin + s->filter_area_length);
485             }
486         } else {
487             start = block->target_start;
488             size_in_block = block->target_end - block->target_start;
489         }
490 
491         if (phys_addr >= start && phys_addr < start + size_in_block) {
492             *p_offset = phys_addr - start + offset;
493 
494             /* The offset range mapped from the vmcore file must not spill over
495              * the GuestPhysBlock, clamp it. The rest of the mapping will be
496              * zero-filled in memory at load time; see
497              * <http://refspecs.linuxbase.org/elf/gabi4+/ch5.pheader.html>.
498              */
499             *p_filesz = phys_addr + mapping_length <= start + size_in_block ?
500                         mapping_length :
501                         size_in_block - (phys_addr - start);
502             return;
503         }
504 
505         offset += size_in_block;
506     }
507 }
508 
509 static void write_elf_phdr_loads(DumpState *s, Error **errp)
510 {
511     ERRP_GUARD();
512     hwaddr offset, filesz;
513     MemoryMapping *memory_mapping;
514     uint32_t phdr_index = 1;
515 
516     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
517         get_offset_range(memory_mapping->phys_addr,
518                          memory_mapping->length,
519                          s, &offset, &filesz);
520         if (dump_is_64bit(s)) {
521             write_elf64_load(s, memory_mapping, phdr_index++, offset,
522                              filesz, errp);
523         } else {
524             write_elf32_load(s, memory_mapping, phdr_index++, offset,
525                              filesz, errp);
526         }
527 
528         if (*errp) {
529             return;
530         }
531 
532         if (phdr_index >= s->phdr_num) {
533             break;
534         }
535     }
536 }
537 
538 static void write_elf_notes(DumpState *s, Error **errp)
539 {
540     if (dump_is_64bit(s)) {
541         write_elf64_notes(fd_write_vmcore, s, errp);
542     } else {
543         write_elf32_notes(fd_write_vmcore, s, errp);
544     }
545 }
546 
547 /* write elf header, PT_NOTE and elf note to vmcore. */
548 static void dump_begin(DumpState *s, Error **errp)
549 {
550     ERRP_GUARD();
551 
552     /*
553      * the vmcore's format is:
554      *   --------------
555      *   |  elf header |
556      *   --------------
557      *   |  PT_NOTE    |
558      *   --------------
559      *   |  PT_LOAD    |
560      *   --------------
561      *   |  ......     |
562      *   --------------
563      *   |  PT_LOAD    |
564      *   --------------
565      *   |  sec_hdr    |
566      *   --------------
567      *   |  elf note   |
568      *   --------------
569      *   |  memory     |
570      *   --------------
571      *
572      * we only know where the memory is saved after we write elf note into
573      * vmcore.
574      */
575 
576     /* write elf header to vmcore */
577     write_elf_header(s, errp);
578     if (*errp) {
579         return;
580     }
581 
582     /* write PT_NOTE to vmcore */
583     write_elf_phdr_note(s, errp);
584     if (*errp) {
585         return;
586     }
587 
588     /* write all PT_LOADs to vmcore */
589     write_elf_phdr_loads(s, errp);
590     if (*errp) {
591         return;
592     }
593 
594     /* write section to vmcore */
595     if (s->shdr_num) {
596         write_elf_section(s, 1, errp);
597         if (*errp) {
598             return;
599         }
600     }
601 
602     /* write notes to vmcore */
603     write_elf_notes(s, errp);
604 }
605 
606 static int64_t dump_filtered_memblock_size(GuestPhysBlock *block,
607                                            int64_t filter_area_start,
608                                            int64_t filter_area_length)
609 {
610     int64_t size, left, right;
611 
612     /* No filter, return full size */
613     if (!filter_area_length) {
614         return block->target_end - block->target_start;
615     }
616 
617     /* calculate the overlapped region. */
618     left = MAX(filter_area_start, block->target_start);
619     right = MIN(filter_area_start + filter_area_length, block->target_end);
620     size = right - left;
621     size = size > 0 ? size : 0;
622 
623     return size;
624 }
625 
626 static int64_t dump_filtered_memblock_start(GuestPhysBlock *block,
627                                             int64_t filter_area_start,
628                                             int64_t filter_area_length)
629 {
630     if (filter_area_length) {
631         /* return -1 if the block is not within filter area */
632         if (block->target_start >= filter_area_start + filter_area_length ||
633             block->target_end <= filter_area_start) {
634             return -1;
635         }
636 
637         if (filter_area_start > block->target_start) {
638             return filter_area_start - block->target_start;
639         }
640     }
641 
642     return 0;
643 }
644 
645 /* write all memory to vmcore */
646 static void dump_iterate(DumpState *s, Error **errp)
647 {
648     ERRP_GUARD();
649     GuestPhysBlock *block;
650     int64_t memblock_size, memblock_start;
651 
652     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
653         memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin, s->filter_area_length);
654         if (memblock_start == -1) {
655             continue;
656         }
657 
658         memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin, s->filter_area_length);
659 
660         /* Write the memory to file */
661         write_memory(s, block, memblock_start, memblock_size, errp);
662         if (*errp) {
663             return;
664         }
665     }
666 }
667 
668 static void create_vmcore(DumpState *s, Error **errp)
669 {
670     ERRP_GUARD();
671 
672     dump_begin(s, errp);
673     if (*errp) {
674         return;
675     }
676 
677     dump_iterate(s, errp);
678 }
679 
680 static int write_start_flat_header(int fd)
681 {
682     MakedumpfileHeader *mh;
683     int ret = 0;
684 
685     QEMU_BUILD_BUG_ON(sizeof *mh > MAX_SIZE_MDF_HEADER);
686     mh = g_malloc0(MAX_SIZE_MDF_HEADER);
687 
688     memcpy(mh->signature, MAKEDUMPFILE_SIGNATURE,
689            MIN(sizeof mh->signature, sizeof MAKEDUMPFILE_SIGNATURE));
690 
691     mh->type = cpu_to_be64(TYPE_FLAT_HEADER);
692     mh->version = cpu_to_be64(VERSION_FLAT_HEADER);
693 
694     size_t written_size;
695     written_size = qemu_write_full(fd, mh, MAX_SIZE_MDF_HEADER);
696     if (written_size != MAX_SIZE_MDF_HEADER) {
697         ret = -1;
698     }
699 
700     g_free(mh);
701     return ret;
702 }
703 
704 static int write_end_flat_header(int fd)
705 {
706     MakedumpfileDataHeader mdh;
707 
708     mdh.offset = END_FLAG_FLAT_HEADER;
709     mdh.buf_size = END_FLAG_FLAT_HEADER;
710 
711     size_t written_size;
712     written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
713     if (written_size != sizeof(mdh)) {
714         return -1;
715     }
716 
717     return 0;
718 }
719 
720 static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
721 {
722     size_t written_size;
723     MakedumpfileDataHeader mdh;
724 
725     mdh.offset = cpu_to_be64(offset);
726     mdh.buf_size = cpu_to_be64(size);
727 
728     written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
729     if (written_size != sizeof(mdh)) {
730         return -1;
731     }
732 
733     written_size = qemu_write_full(fd, buf, size);
734     if (written_size != size) {
735         return -1;
736     }
737 
738     return 0;
739 }
740 
741 static int buf_write_note(const void *buf, size_t size, void *opaque)
742 {
743     DumpState *s = opaque;
744 
745     /* note_buf is not enough */
746     if (s->note_buf_offset + size > s->note_size) {
747         return -1;
748     }
749 
750     memcpy(s->note_buf + s->note_buf_offset, buf, size);
751 
752     s->note_buf_offset += size;
753 
754     return 0;
755 }
756 
757 /*
758  * This function retrieves various sizes from an elf header.
759  *
760  * @note has to be a valid ELF note. The return sizes are unmodified
761  * (not padded or rounded up to be multiple of 4).
762  */
763 static void get_note_sizes(DumpState *s, const void *note,
764                            uint64_t *note_head_size,
765                            uint64_t *name_size,
766                            uint64_t *desc_size)
767 {
768     uint64_t note_head_sz;
769     uint64_t name_sz;
770     uint64_t desc_sz;
771 
772     if (dump_is_64bit(s)) {
773         const Elf64_Nhdr *hdr = note;
774         note_head_sz = sizeof(Elf64_Nhdr);
775         name_sz = tswap64(hdr->n_namesz);
776         desc_sz = tswap64(hdr->n_descsz);
777     } else {
778         const Elf32_Nhdr *hdr = note;
779         note_head_sz = sizeof(Elf32_Nhdr);
780         name_sz = tswap32(hdr->n_namesz);
781         desc_sz = tswap32(hdr->n_descsz);
782     }
783 
784     if (note_head_size) {
785         *note_head_size = note_head_sz;
786     }
787     if (name_size) {
788         *name_size = name_sz;
789     }
790     if (desc_size) {
791         *desc_size = desc_sz;
792     }
793 }
794 
795 static bool note_name_equal(DumpState *s,
796                             const uint8_t *note, const char *name)
797 {
798     int len = strlen(name) + 1;
799     uint64_t head_size, name_size;
800 
801     get_note_sizes(s, note, &head_size, &name_size, NULL);
802     head_size = ROUND_UP(head_size, 4);
803 
804     return name_size == len && memcmp(note + head_size, name, len) == 0;
805 }
806 
807 /* write common header, sub header and elf note to vmcore */
808 static void create_header32(DumpState *s, Error **errp)
809 {
810     ERRP_GUARD();
811     DiskDumpHeader32 *dh = NULL;
812     KdumpSubHeader32 *kh = NULL;
813     size_t size;
814     uint32_t block_size;
815     uint32_t sub_hdr_size;
816     uint32_t bitmap_blocks;
817     uint32_t status = 0;
818     uint64_t offset_note;
819 
820     /* write common header, the version of kdump-compressed format is 6th */
821     size = sizeof(DiskDumpHeader32);
822     dh = g_malloc0(size);
823 
824     memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
825     dh->header_version = cpu_to_dump32(s, 6);
826     block_size = s->dump_info.page_size;
827     dh->block_size = cpu_to_dump32(s, block_size);
828     sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
829     sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
830     dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
831     /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
832     dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
833     dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
834     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
835     dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
836     strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
837 
838     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
839         status |= DUMP_DH_COMPRESSED_ZLIB;
840     }
841 #ifdef CONFIG_LZO
842     if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
843         status |= DUMP_DH_COMPRESSED_LZO;
844     }
845 #endif
846 #ifdef CONFIG_SNAPPY
847     if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
848         status |= DUMP_DH_COMPRESSED_SNAPPY;
849     }
850 #endif
851     dh->status = cpu_to_dump32(s, status);
852 
853     if (write_buffer(s->fd, 0, dh, size) < 0) {
854         error_setg(errp, "dump: failed to write disk dump header");
855         goto out;
856     }
857 
858     /* write sub header */
859     size = sizeof(KdumpSubHeader32);
860     kh = g_malloc0(size);
861 
862     /* 64bit max_mapnr_64 */
863     kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
864     kh->phys_base = cpu_to_dump32(s, s->dump_info.phys_base);
865     kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
866 
867     offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
868     if (s->guest_note &&
869         note_name_equal(s, s->guest_note, "VMCOREINFO")) {
870         uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
871 
872         get_note_sizes(s, s->guest_note,
873                        &hsize, &name_size, &size_vmcoreinfo_desc);
874         offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
875             (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
876         kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
877         kh->size_vmcoreinfo = cpu_to_dump32(s, size_vmcoreinfo_desc);
878     }
879 
880     kh->offset_note = cpu_to_dump64(s, offset_note);
881     kh->note_size = cpu_to_dump32(s, s->note_size);
882 
883     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
884                      block_size, kh, size) < 0) {
885         error_setg(errp, "dump: failed to write kdump sub header");
886         goto out;
887     }
888 
889     /* write note */
890     s->note_buf = g_malloc0(s->note_size);
891     s->note_buf_offset = 0;
892 
893     /* use s->note_buf to store notes temporarily */
894     write_elf32_notes(buf_write_note, s, errp);
895     if (*errp) {
896         goto out;
897     }
898     if (write_buffer(s->fd, offset_note, s->note_buf,
899                      s->note_size) < 0) {
900         error_setg(errp, "dump: failed to write notes");
901         goto out;
902     }
903 
904     /* get offset of dump_bitmap */
905     s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
906                              block_size;
907 
908     /* get offset of page */
909     s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
910                      block_size;
911 
912 out:
913     g_free(dh);
914     g_free(kh);
915     g_free(s->note_buf);
916 }
917 
918 /* write common header, sub header and elf note to vmcore */
919 static void create_header64(DumpState *s, Error **errp)
920 {
921     ERRP_GUARD();
922     DiskDumpHeader64 *dh = NULL;
923     KdumpSubHeader64 *kh = NULL;
924     size_t size;
925     uint32_t block_size;
926     uint32_t sub_hdr_size;
927     uint32_t bitmap_blocks;
928     uint32_t status = 0;
929     uint64_t offset_note;
930 
931     /* write common header, the version of kdump-compressed format is 6th */
932     size = sizeof(DiskDumpHeader64);
933     dh = g_malloc0(size);
934 
935     memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
936     dh->header_version = cpu_to_dump32(s, 6);
937     block_size = s->dump_info.page_size;
938     dh->block_size = cpu_to_dump32(s, block_size);
939     sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
940     sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
941     dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
942     /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
943     dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
944     dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
945     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
946     dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
947     strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
948 
949     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
950         status |= DUMP_DH_COMPRESSED_ZLIB;
951     }
952 #ifdef CONFIG_LZO
953     if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
954         status |= DUMP_DH_COMPRESSED_LZO;
955     }
956 #endif
957 #ifdef CONFIG_SNAPPY
958     if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
959         status |= DUMP_DH_COMPRESSED_SNAPPY;
960     }
961 #endif
962     dh->status = cpu_to_dump32(s, status);
963 
964     if (write_buffer(s->fd, 0, dh, size) < 0) {
965         error_setg(errp, "dump: failed to write disk dump header");
966         goto out;
967     }
968 
969     /* write sub header */
970     size = sizeof(KdumpSubHeader64);
971     kh = g_malloc0(size);
972 
973     /* 64bit max_mapnr_64 */
974     kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
975     kh->phys_base = cpu_to_dump64(s, s->dump_info.phys_base);
976     kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
977 
978     offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
979     if (s->guest_note &&
980         note_name_equal(s, s->guest_note, "VMCOREINFO")) {
981         uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
982 
983         get_note_sizes(s, s->guest_note,
984                        &hsize, &name_size, &size_vmcoreinfo_desc);
985         offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
986             (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
987         kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
988         kh->size_vmcoreinfo = cpu_to_dump64(s, size_vmcoreinfo_desc);
989     }
990 
991     kh->offset_note = cpu_to_dump64(s, offset_note);
992     kh->note_size = cpu_to_dump64(s, s->note_size);
993 
994     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
995                      block_size, kh, size) < 0) {
996         error_setg(errp, "dump: failed to write kdump sub header");
997         goto out;
998     }
999 
1000     /* write note */
1001     s->note_buf = g_malloc0(s->note_size);
1002     s->note_buf_offset = 0;
1003 
1004     /* use s->note_buf to store notes temporarily */
1005     write_elf64_notes(buf_write_note, s, errp);
1006     if (*errp) {
1007         goto out;
1008     }
1009 
1010     if (write_buffer(s->fd, offset_note, s->note_buf,
1011                      s->note_size) < 0) {
1012         error_setg(errp, "dump: failed to write notes");
1013         goto out;
1014     }
1015 
1016     /* get offset of dump_bitmap */
1017     s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
1018                              block_size;
1019 
1020     /* get offset of page */
1021     s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
1022                      block_size;
1023 
1024 out:
1025     g_free(dh);
1026     g_free(kh);
1027     g_free(s->note_buf);
1028 }
1029 
1030 static void write_dump_header(DumpState *s, Error **errp)
1031 {
1032     if (dump_is_64bit(s)) {
1033         create_header64(s, errp);
1034     } else {
1035         create_header32(s, errp);
1036     }
1037 }
1038 
1039 static size_t dump_bitmap_get_bufsize(DumpState *s)
1040 {
1041     return s->dump_info.page_size;
1042 }
1043 
1044 /*
1045  * set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
1046  * rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
1047  * set_dump_bitmap will always leave the recently set bit un-sync. And setting
1048  * (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
1049  * vmcore, ie. synchronizing un-sync bit into vmcore.
1050  */
1051 static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
1052                            uint8_t *buf, DumpState *s)
1053 {
1054     off_t old_offset, new_offset;
1055     off_t offset_bitmap1, offset_bitmap2;
1056     uint32_t byte, bit;
1057     size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
1058     size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
1059 
1060     /* should not set the previous place */
1061     assert(last_pfn <= pfn);
1062 
1063     /*
1064      * if the bit needed to be set is not cached in buf, flush the data in buf
1065      * to vmcore firstly.
1066      * making new_offset be bigger than old_offset can also sync remained data
1067      * into vmcore.
1068      */
1069     old_offset = bitmap_bufsize * (last_pfn / bits_per_buf);
1070     new_offset = bitmap_bufsize * (pfn / bits_per_buf);
1071 
1072     while (old_offset < new_offset) {
1073         /* calculate the offset and write dump_bitmap */
1074         offset_bitmap1 = s->offset_dump_bitmap + old_offset;
1075         if (write_buffer(s->fd, offset_bitmap1, buf,
1076                          bitmap_bufsize) < 0) {
1077             return -1;
1078         }
1079 
1080         /* dump level 1 is chosen, so 1st and 2nd bitmap are same */
1081         offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
1082                          old_offset;
1083         if (write_buffer(s->fd, offset_bitmap2, buf,
1084                          bitmap_bufsize) < 0) {
1085             return -1;
1086         }
1087 
1088         memset(buf, 0, bitmap_bufsize);
1089         old_offset += bitmap_bufsize;
1090     }
1091 
1092     /* get the exact place of the bit in the buf, and set it */
1093     byte = (pfn % bits_per_buf) / CHAR_BIT;
1094     bit = (pfn % bits_per_buf) % CHAR_BIT;
1095     if (value) {
1096         buf[byte] |= 1u << bit;
1097     } else {
1098         buf[byte] &= ~(1u << bit);
1099     }
1100 
1101     return 0;
1102 }
1103 
1104 static uint64_t dump_paddr_to_pfn(DumpState *s, uint64_t addr)
1105 {
1106     int target_page_shift = ctz32(s->dump_info.page_size);
1107 
1108     return (addr >> target_page_shift) - ARCH_PFN_OFFSET;
1109 }
1110 
1111 static uint64_t dump_pfn_to_paddr(DumpState *s, uint64_t pfn)
1112 {
1113     int target_page_shift = ctz32(s->dump_info.page_size);
1114 
1115     return (pfn + ARCH_PFN_OFFSET) << target_page_shift;
1116 }
1117 
1118 /*
1119  * Return the page frame number and the page content in *bufptr. bufptr can be
1120  * NULL. If not NULL, *bufptr must contains a target page size of pre-allocated
1121  * memory. This is not necessarily the memory returned.
1122  */
1123 static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
1124                           uint8_t **bufptr, DumpState *s)
1125 {
1126     GuestPhysBlock *block = *blockptr;
1127     uint32_t page_size = s->dump_info.page_size;
1128     uint8_t *buf = NULL, *hbuf;
1129     hwaddr addr;
1130 
1131     /* block == NULL means the start of the iteration */
1132     if (!block) {
1133         block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
1134         *blockptr = block;
1135         addr = block->target_start;
1136         *pfnptr = dump_paddr_to_pfn(s, addr);
1137     } else {
1138         *pfnptr += 1;
1139         addr = dump_pfn_to_paddr(s, *pfnptr);
1140     }
1141     assert(block != NULL);
1142 
1143     while (1) {
1144         if (addr >= block->target_start && addr < block->target_end) {
1145             size_t n = MIN(block->target_end - addr, page_size - addr % page_size);
1146             hbuf = block->host_addr + (addr - block->target_start);
1147             if (!buf) {
1148                 if (n == page_size) {
1149                     /* this is a whole target page, go for it */
1150                     assert(addr % page_size == 0);
1151                     buf = hbuf;
1152                     break;
1153                 } else if (bufptr) {
1154                     assert(*bufptr);
1155                     buf = *bufptr;
1156                     memset(buf, 0, page_size);
1157                 } else {
1158                     return true;
1159                 }
1160             }
1161 
1162             memcpy(buf + addr % page_size, hbuf, n);
1163             addr += n;
1164             if (addr % page_size == 0) {
1165                 /* we filled up the page */
1166                 break;
1167             }
1168         } else {
1169             /* the next page is in the next block */
1170             *blockptr = block = QTAILQ_NEXT(block, next);
1171             if (!block) {
1172                 break;
1173             }
1174 
1175             addr = block->target_start;
1176             /* are we still in the same page? */
1177             if (dump_paddr_to_pfn(s, addr) != *pfnptr) {
1178                 if (buf) {
1179                     /* no, but we already filled something earlier, return it */
1180                     break;
1181                 } else {
1182                     /* else continue from there */
1183                     *pfnptr = dump_paddr_to_pfn(s, addr);
1184                 }
1185             }
1186         }
1187     }
1188 
1189     if (bufptr) {
1190         *bufptr = buf;
1191     }
1192 
1193     return buf != NULL;
1194 }
1195 
1196 static void write_dump_bitmap(DumpState *s, Error **errp)
1197 {
1198     int ret = 0;
1199     uint64_t last_pfn, pfn;
1200     void *dump_bitmap_buf;
1201     size_t num_dumpable;
1202     GuestPhysBlock *block_iter = NULL;
1203     size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
1204     size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
1205 
1206     /* dump_bitmap_buf is used to store dump_bitmap temporarily */
1207     dump_bitmap_buf = g_malloc0(bitmap_bufsize);
1208 
1209     num_dumpable = 0;
1210     last_pfn = 0;
1211 
1212     /*
1213      * exam memory page by page, and set the bit in dump_bitmap corresponded
1214      * to the existing page.
1215      */
1216     while (get_next_page(&block_iter, &pfn, NULL, s)) {
1217         ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
1218         if (ret < 0) {
1219             error_setg(errp, "dump: failed to set dump_bitmap");
1220             goto out;
1221         }
1222 
1223         last_pfn = pfn;
1224         num_dumpable++;
1225     }
1226 
1227     /*
1228      * set_dump_bitmap will always leave the recently set bit un-sync. Here we
1229      * set the remaining bits from last_pfn to the end of the bitmap buffer to
1230      * 0. With those set, the un-sync bit will be synchronized into the vmcore.
1231      */
1232     if (num_dumpable > 0) {
1233         ret = set_dump_bitmap(last_pfn, last_pfn + bits_per_buf, false,
1234                               dump_bitmap_buf, s);
1235         if (ret < 0) {
1236             error_setg(errp, "dump: failed to sync dump_bitmap");
1237             goto out;
1238         }
1239     }
1240 
1241     /* number of dumpable pages that will be dumped later */
1242     s->num_dumpable = num_dumpable;
1243 
1244 out:
1245     g_free(dump_bitmap_buf);
1246 }
1247 
1248 static void prepare_data_cache(DataCache *data_cache, DumpState *s,
1249                                off_t offset)
1250 {
1251     data_cache->fd = s->fd;
1252     data_cache->data_size = 0;
1253     data_cache->buf_size = 4 * dump_bitmap_get_bufsize(s);
1254     data_cache->buf = g_malloc0(data_cache->buf_size);
1255     data_cache->offset = offset;
1256 }
1257 
1258 static int write_cache(DataCache *dc, const void *buf, size_t size,
1259                        bool flag_sync)
1260 {
1261     /*
1262      * dc->buf_size should not be less than size, otherwise dc will never be
1263      * enough
1264      */
1265     assert(size <= dc->buf_size);
1266 
1267     /*
1268      * if flag_sync is set, synchronize data in dc->buf into vmcore.
1269      * otherwise check if the space is enough for caching data in buf, if not,
1270      * write the data in dc->buf to dc->fd and reset dc->buf
1271      */
1272     if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
1273         (flag_sync && dc->data_size > 0)) {
1274         if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) {
1275             return -1;
1276         }
1277 
1278         dc->offset += dc->data_size;
1279         dc->data_size = 0;
1280     }
1281 
1282     if (!flag_sync) {
1283         memcpy(dc->buf + dc->data_size, buf, size);
1284         dc->data_size += size;
1285     }
1286 
1287     return 0;
1288 }
1289 
1290 static void free_data_cache(DataCache *data_cache)
1291 {
1292     g_free(data_cache->buf);
1293 }
1294 
1295 static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
1296 {
1297     switch (flag_compress) {
1298     case DUMP_DH_COMPRESSED_ZLIB:
1299         return compressBound(page_size);
1300 
1301     case DUMP_DH_COMPRESSED_LZO:
1302         /*
1303          * LZO will expand incompressible data by a little amount. Please check
1304          * the following URL to see the expansion calculation:
1305          * http://www.oberhumer.com/opensource/lzo/lzofaq.php
1306          */
1307         return page_size + page_size / 16 + 64 + 3;
1308 
1309 #ifdef CONFIG_SNAPPY
1310     case DUMP_DH_COMPRESSED_SNAPPY:
1311         return snappy_max_compressed_length(page_size);
1312 #endif
1313     }
1314     return 0;
1315 }
1316 
1317 static void write_dump_pages(DumpState *s, Error **errp)
1318 {
1319     int ret = 0;
1320     DataCache page_desc, page_data;
1321     size_t len_buf_out, size_out;
1322 #ifdef CONFIG_LZO
1323     lzo_bytep wrkmem = NULL;
1324 #endif
1325     uint8_t *buf_out = NULL;
1326     off_t offset_desc, offset_data;
1327     PageDescriptor pd, pd_zero;
1328     uint8_t *buf;
1329     GuestPhysBlock *block_iter = NULL;
1330     uint64_t pfn_iter;
1331     g_autofree uint8_t *page = NULL;
1332 
1333     /* get offset of page_desc and page_data in dump file */
1334     offset_desc = s->offset_page;
1335     offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
1336 
1337     prepare_data_cache(&page_desc, s, offset_desc);
1338     prepare_data_cache(&page_data, s, offset_data);
1339 
1340     /* prepare buffer to store compressed data */
1341     len_buf_out = get_len_buf_out(s->dump_info.page_size, s->flag_compress);
1342     assert(len_buf_out != 0);
1343 
1344 #ifdef CONFIG_LZO
1345     wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
1346 #endif
1347 
1348     buf_out = g_malloc(len_buf_out);
1349 
1350     /*
1351      * init zero page's page_desc and page_data, because every zero page
1352      * uses the same page_data
1353      */
1354     pd_zero.size = cpu_to_dump32(s, s->dump_info.page_size);
1355     pd_zero.flags = cpu_to_dump32(s, 0);
1356     pd_zero.offset = cpu_to_dump64(s, offset_data);
1357     pd_zero.page_flags = cpu_to_dump64(s, 0);
1358     buf = g_malloc0(s->dump_info.page_size);
1359     ret = write_cache(&page_data, buf, s->dump_info.page_size, false);
1360     g_free(buf);
1361     if (ret < 0) {
1362         error_setg(errp, "dump: failed to write page data (zero page)");
1363         goto out;
1364     }
1365 
1366     offset_data += s->dump_info.page_size;
1367     page = g_malloc(s->dump_info.page_size);
1368 
1369     /*
1370      * dump memory to vmcore page by page. zero page will all be resided in the
1371      * first page of page section
1372      */
1373     for (buf = page; get_next_page(&block_iter, &pfn_iter, &buf, s); buf = page) {
1374         /* check zero page */
1375         if (buffer_is_zero(buf, s->dump_info.page_size)) {
1376             ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
1377                               false);
1378             if (ret < 0) {
1379                 error_setg(errp, "dump: failed to write page desc");
1380                 goto out;
1381             }
1382         } else {
1383             /*
1384              * not zero page, then:
1385              * 1. compress the page
1386              * 2. write the compressed page into the cache of page_data
1387              * 3. get page desc of the compressed page and write it into the
1388              *    cache of page_desc
1389              *
1390              * only one compression format will be used here, for
1391              * s->flag_compress is set. But when compression fails to work,
1392              * we fall back to save in plaintext.
1393              */
1394              size_out = len_buf_out;
1395              if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
1396                     (compress2(buf_out, (uLongf *)&size_out, buf,
1397                                s->dump_info.page_size, Z_BEST_SPEED) == Z_OK) &&
1398                     (size_out < s->dump_info.page_size)) {
1399                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_ZLIB);
1400                 pd.size  = cpu_to_dump32(s, size_out);
1401 
1402                 ret = write_cache(&page_data, buf_out, size_out, false);
1403                 if (ret < 0) {
1404                     error_setg(errp, "dump: failed to write page data");
1405                     goto out;
1406                 }
1407 #ifdef CONFIG_LZO
1408             } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
1409                     (lzo1x_1_compress(buf, s->dump_info.page_size, buf_out,
1410                     (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
1411                     (size_out < s->dump_info.page_size)) {
1412                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_LZO);
1413                 pd.size  = cpu_to_dump32(s, size_out);
1414 
1415                 ret = write_cache(&page_data, buf_out, size_out, false);
1416                 if (ret < 0) {
1417                     error_setg(errp, "dump: failed to write page data");
1418                     goto out;
1419                 }
1420 #endif
1421 #ifdef CONFIG_SNAPPY
1422             } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
1423                     (snappy_compress((char *)buf, s->dump_info.page_size,
1424                     (char *)buf_out, &size_out) == SNAPPY_OK) &&
1425                     (size_out < s->dump_info.page_size)) {
1426                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_SNAPPY);
1427                 pd.size  = cpu_to_dump32(s, size_out);
1428 
1429                 ret = write_cache(&page_data, buf_out, size_out, false);
1430                 if (ret < 0) {
1431                     error_setg(errp, "dump: failed to write page data");
1432                     goto out;
1433                 }
1434 #endif
1435             } else {
1436                 /*
1437                  * fall back to save in plaintext, size_out should be
1438                  * assigned the target's page size
1439                  */
1440                 pd.flags = cpu_to_dump32(s, 0);
1441                 size_out = s->dump_info.page_size;
1442                 pd.size = cpu_to_dump32(s, size_out);
1443 
1444                 ret = write_cache(&page_data, buf,
1445                                   s->dump_info.page_size, false);
1446                 if (ret < 0) {
1447                     error_setg(errp, "dump: failed to write page data");
1448                     goto out;
1449                 }
1450             }
1451 
1452             /* get and write page desc here */
1453             pd.page_flags = cpu_to_dump64(s, 0);
1454             pd.offset = cpu_to_dump64(s, offset_data);
1455             offset_data += size_out;
1456 
1457             ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
1458             if (ret < 0) {
1459                 error_setg(errp, "dump: failed to write page desc");
1460                 goto out;
1461             }
1462         }
1463         s->written_size += s->dump_info.page_size;
1464     }
1465 
1466     ret = write_cache(&page_desc, NULL, 0, true);
1467     if (ret < 0) {
1468         error_setg(errp, "dump: failed to sync cache for page_desc");
1469         goto out;
1470     }
1471     ret = write_cache(&page_data, NULL, 0, true);
1472     if (ret < 0) {
1473         error_setg(errp, "dump: failed to sync cache for page_data");
1474         goto out;
1475     }
1476 
1477 out:
1478     free_data_cache(&page_desc);
1479     free_data_cache(&page_data);
1480 
1481 #ifdef CONFIG_LZO
1482     g_free(wrkmem);
1483 #endif
1484 
1485     g_free(buf_out);
1486 }
1487 
1488 static void create_kdump_vmcore(DumpState *s, Error **errp)
1489 {
1490     ERRP_GUARD();
1491     int ret;
1492 
1493     /*
1494      * the kdump-compressed format is:
1495      *                                               File offset
1496      *  +------------------------------------------+ 0x0
1497      *  |    main header (struct disk_dump_header) |
1498      *  |------------------------------------------+ block 1
1499      *  |    sub header (struct kdump_sub_header)  |
1500      *  |------------------------------------------+ block 2
1501      *  |            1st-dump_bitmap               |
1502      *  |------------------------------------------+ block 2 + X blocks
1503      *  |            2nd-dump_bitmap               | (aligned by block)
1504      *  |------------------------------------------+ block 2 + 2 * X blocks
1505      *  |  page desc for pfn 0 (struct page_desc)  | (aligned by block)
1506      *  |  page desc for pfn 1 (struct page_desc)  |
1507      *  |                    :                     |
1508      *  |------------------------------------------| (not aligned by block)
1509      *  |         page data (pfn 0)                |
1510      *  |         page data (pfn 1)                |
1511      *  |                    :                     |
1512      *  +------------------------------------------+
1513      */
1514 
1515     ret = write_start_flat_header(s->fd);
1516     if (ret < 0) {
1517         error_setg(errp, "dump: failed to write start flat header");
1518         return;
1519     }
1520 
1521     write_dump_header(s, errp);
1522     if (*errp) {
1523         return;
1524     }
1525 
1526     write_dump_bitmap(s, errp);
1527     if (*errp) {
1528         return;
1529     }
1530 
1531     write_dump_pages(s, errp);
1532     if (*errp) {
1533         return;
1534     }
1535 
1536     ret = write_end_flat_header(s->fd);
1537     if (ret < 0) {
1538         error_setg(errp, "dump: failed to write end flat header");
1539         return;
1540     }
1541 }
1542 
1543 static int validate_start_block(DumpState *s)
1544 {
1545     GuestPhysBlock *block;
1546 
1547     if (!dump_has_filter(s)) {
1548         return 0;
1549     }
1550 
1551     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1552         /* This block is out of the range */
1553         if (block->target_start >= s->filter_area_begin + s->filter_area_length ||
1554             block->target_end <= s->filter_area_begin) {
1555             continue;
1556         }
1557         return 0;
1558    }
1559 
1560     return -1;
1561 }
1562 
1563 static void get_max_mapnr(DumpState *s)
1564 {
1565     GuestPhysBlock *last_block;
1566 
1567     last_block = QTAILQ_LAST(&s->guest_phys_blocks.head);
1568     s->max_mapnr = dump_paddr_to_pfn(s, last_block->target_end);
1569 }
1570 
1571 static DumpState dump_state_global = { .status = DUMP_STATUS_NONE };
1572 
1573 static void dump_state_prepare(DumpState *s)
1574 {
1575     /* zero the struct, setting status to active */
1576     *s = (DumpState) { .status = DUMP_STATUS_ACTIVE };
1577 }
1578 
1579 bool qemu_system_dump_in_progress(void)
1580 {
1581     DumpState *state = &dump_state_global;
1582     return (qatomic_read(&state->status) == DUMP_STATUS_ACTIVE);
1583 }
1584 
1585 /*
1586  * calculate total size of memory to be dumped (taking filter into
1587  * account.)
1588  */
1589 static int64_t dump_calculate_size(DumpState *s)
1590 {
1591     GuestPhysBlock *block;
1592     int64_t total = 0;
1593 
1594     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1595         total += dump_filtered_memblock_size(block,
1596                                              s->filter_area_begin,
1597                                              s->filter_area_length);
1598     }
1599 
1600     return total;
1601 }
1602 
1603 static void vmcoreinfo_update_phys_base(DumpState *s)
1604 {
1605     uint64_t size, note_head_size, name_size, phys_base;
1606     char **lines;
1607     uint8_t *vmci;
1608     size_t i;
1609 
1610     if (!note_name_equal(s, s->guest_note, "VMCOREINFO")) {
1611         return;
1612     }
1613 
1614     get_note_sizes(s, s->guest_note, &note_head_size, &name_size, &size);
1615     note_head_size = ROUND_UP(note_head_size, 4);
1616 
1617     vmci = s->guest_note + note_head_size + ROUND_UP(name_size, 4);
1618     *(vmci + size) = '\0';
1619 
1620     lines = g_strsplit((char *)vmci, "\n", -1);
1621     for (i = 0; lines[i]; i++) {
1622         const char *prefix = NULL;
1623 
1624         if (s->dump_info.d_machine == EM_X86_64) {
1625             prefix = "NUMBER(phys_base)=";
1626         } else if (s->dump_info.d_machine == EM_AARCH64) {
1627             prefix = "NUMBER(PHYS_OFFSET)=";
1628         }
1629 
1630         if (prefix && g_str_has_prefix(lines[i], prefix)) {
1631             if (qemu_strtou64(lines[i] + strlen(prefix), NULL, 16,
1632                               &phys_base) < 0) {
1633                 warn_report("Failed to read %s", prefix);
1634             } else {
1635                 s->dump_info.phys_base = phys_base;
1636             }
1637             break;
1638         }
1639     }
1640 
1641     g_strfreev(lines);
1642 }
1643 
1644 static void dump_init(DumpState *s, int fd, bool has_format,
1645                       DumpGuestMemoryFormat format, bool paging, bool has_filter,
1646                       int64_t begin, int64_t length, Error **errp)
1647 {
1648     ERRP_GUARD();
1649     VMCoreInfoState *vmci = vmcoreinfo_find();
1650     CPUState *cpu;
1651     int nr_cpus;
1652     int ret;
1653 
1654     s->has_format = has_format;
1655     s->format = format;
1656     s->written_size = 0;
1657 
1658     /* kdump-compressed is conflict with paging and filter */
1659     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1660         assert(!paging && !has_filter);
1661     }
1662 
1663     if (runstate_is_running()) {
1664         vm_stop(RUN_STATE_SAVE_VM);
1665         s->resume = true;
1666     } else {
1667         s->resume = false;
1668     }
1669 
1670     /* If we use KVM, we should synchronize the registers before we get dump
1671      * info or physmap info.
1672      */
1673     cpu_synchronize_all_states();
1674     nr_cpus = 0;
1675     CPU_FOREACH(cpu) {
1676         nr_cpus++;
1677     }
1678 
1679     s->fd = fd;
1680     if (has_filter && !length) {
1681         error_setg(errp, QERR_INVALID_PARAMETER, "length");
1682         goto cleanup;
1683     }
1684     s->filter_area_begin = begin;
1685     s->filter_area_length = length;
1686 
1687     memory_mapping_list_init(&s->list);
1688 
1689     guest_phys_blocks_init(&s->guest_phys_blocks);
1690     guest_phys_blocks_append(&s->guest_phys_blocks);
1691     s->total_size = dump_calculate_size(s);
1692 #ifdef DEBUG_DUMP_GUEST_MEMORY
1693     fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
1694 #endif
1695 
1696     /* it does not make sense to dump non-existent memory */
1697     if (!s->total_size) {
1698         error_setg(errp, "dump: no guest memory to dump");
1699         goto cleanup;
1700     }
1701 
1702     /* Is the filter filtering everything? */
1703     if (validate_start_block(s) == -1) {
1704         error_setg(errp, QERR_INVALID_PARAMETER, "begin");
1705         goto cleanup;
1706     }
1707 
1708     /* get dump info: endian, class and architecture.
1709      * If the target architecture is not supported, cpu_get_dump_info() will
1710      * return -1.
1711      */
1712     ret = cpu_get_dump_info(&s->dump_info, &s->guest_phys_blocks);
1713     if (ret < 0) {
1714         error_setg(errp, QERR_UNSUPPORTED);
1715         goto cleanup;
1716     }
1717 
1718     if (!s->dump_info.page_size) {
1719         s->dump_info.page_size = TARGET_PAGE_SIZE;
1720     }
1721 
1722     s->note_size = cpu_get_note_size(s->dump_info.d_class,
1723                                      s->dump_info.d_machine, nr_cpus);
1724     if (s->note_size < 0) {
1725         error_setg(errp, QERR_UNSUPPORTED);
1726         goto cleanup;
1727     }
1728 
1729     /*
1730      * The goal of this block is to (a) update the previously guessed
1731      * phys_base, (b) copy the guest note out of the guest.
1732      * Failure to do so is not fatal for dumping.
1733      */
1734     if (vmci) {
1735         uint64_t addr, note_head_size, name_size, desc_size;
1736         uint32_t size;
1737         uint16_t format;
1738 
1739         note_head_size = dump_is_64bit(s) ?
1740             sizeof(Elf64_Nhdr) : sizeof(Elf32_Nhdr);
1741 
1742         format = le16_to_cpu(vmci->vmcoreinfo.guest_format);
1743         size = le32_to_cpu(vmci->vmcoreinfo.size);
1744         addr = le64_to_cpu(vmci->vmcoreinfo.paddr);
1745         if (!vmci->has_vmcoreinfo) {
1746             warn_report("guest note is not present");
1747         } else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) {
1748             warn_report("guest note size is invalid: %" PRIu32, size);
1749         } else if (format != FW_CFG_VMCOREINFO_FORMAT_ELF) {
1750             warn_report("guest note format is unsupported: %" PRIu16, format);
1751         } else {
1752             s->guest_note = g_malloc(size + 1); /* +1 for adding \0 */
1753             cpu_physical_memory_read(addr, s->guest_note, size);
1754 
1755             get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_size);
1756             s->guest_note_size = ELF_NOTE_SIZE(note_head_size, name_size,
1757                                                desc_size);
1758             if (name_size > MAX_GUEST_NOTE_SIZE ||
1759                 desc_size > MAX_GUEST_NOTE_SIZE ||
1760                 s->guest_note_size > size) {
1761                 warn_report("Invalid guest note header");
1762                 g_free(s->guest_note);
1763                 s->guest_note = NULL;
1764             } else {
1765                 vmcoreinfo_update_phys_base(s);
1766                 s->note_size += s->guest_note_size;
1767             }
1768         }
1769     }
1770 
1771     /* get memory mapping */
1772     if (paging) {
1773         qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, errp);
1774         if (*errp) {
1775             goto cleanup;
1776         }
1777     } else {
1778         qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
1779     }
1780 
1781     s->nr_cpus = nr_cpus;
1782 
1783     get_max_mapnr(s);
1784 
1785     uint64_t tmp;
1786     tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT),
1787                        s->dump_info.page_size);
1788     s->len_dump_bitmap = tmp * s->dump_info.page_size;
1789 
1790     /* init for kdump-compressed format */
1791     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1792         switch (format) {
1793         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
1794             s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
1795             break;
1796 
1797         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
1798 #ifdef CONFIG_LZO
1799             if (lzo_init() != LZO_E_OK) {
1800                 error_setg(errp, "failed to initialize the LZO library");
1801                 goto cleanup;
1802             }
1803 #endif
1804             s->flag_compress = DUMP_DH_COMPRESSED_LZO;
1805             break;
1806 
1807         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
1808             s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
1809             break;
1810 
1811         default:
1812             s->flag_compress = 0;
1813         }
1814 
1815         return;
1816     }
1817 
1818     if (dump_has_filter(s)) {
1819         memory_mapping_filter(&s->list, s->filter_area_begin, s->filter_area_length);
1820     }
1821 
1822     /*
1823      * calculate phdr_num
1824      *
1825      * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
1826      */
1827     s->phdr_num = 1; /* PT_NOTE */
1828     if (s->list.num < UINT16_MAX - 2) {
1829         s->shdr_num = 0;
1830         s->phdr_num += s->list.num;
1831     } else {
1832         /* sh_info of section 0 holds the real number of phdrs */
1833         s->shdr_num = 1;
1834 
1835         /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
1836         if (s->list.num <= UINT32_MAX - 1) {
1837             s->phdr_num += s->list.num;
1838         } else {
1839             s->phdr_num = UINT32_MAX;
1840         }
1841     }
1842 
1843     if (dump_is_64bit(s)) {
1844         s->phdr_offset = sizeof(Elf64_Ehdr);
1845         s->shdr_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
1846         s->note_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
1847         s->memory_offset = s->note_offset + s->note_size;
1848     } else {
1849 
1850         s->phdr_offset = sizeof(Elf32_Ehdr);
1851         s->shdr_offset = s->phdr_offset + sizeof(Elf32_Phdr) * s->phdr_num;
1852         s->note_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
1853         s->memory_offset = s->note_offset + s->note_size;
1854     }
1855 
1856     return;
1857 
1858 cleanup:
1859     dump_cleanup(s);
1860 }
1861 
1862 /* this operation might be time consuming. */
1863 static void dump_process(DumpState *s, Error **errp)
1864 {
1865     ERRP_GUARD();
1866     DumpQueryResult *result = NULL;
1867 
1868     if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
1869 #ifdef TARGET_X86_64
1870         create_win_dump(s, errp);
1871 #endif
1872     } else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1873         create_kdump_vmcore(s, errp);
1874     } else {
1875         create_vmcore(s, errp);
1876     }
1877 
1878     /* make sure status is written after written_size updates */
1879     smp_wmb();
1880     qatomic_set(&s->status,
1881                (*errp ? DUMP_STATUS_FAILED : DUMP_STATUS_COMPLETED));
1882 
1883     /* send DUMP_COMPLETED message (unconditionally) */
1884     result = qmp_query_dump(NULL);
1885     /* should never fail */
1886     assert(result);
1887     qapi_event_send_dump_completed(result, !!*errp, (*errp ?
1888                                                      error_get_pretty(*errp) : NULL));
1889     qapi_free_DumpQueryResult(result);
1890 
1891     dump_cleanup(s);
1892 }
1893 
1894 static void *dump_thread(void *data)
1895 {
1896     DumpState *s = (DumpState *)data;
1897     dump_process(s, NULL);
1898     return NULL;
1899 }
1900 
1901 DumpQueryResult *qmp_query_dump(Error **errp)
1902 {
1903     DumpQueryResult *result = g_new(DumpQueryResult, 1);
1904     DumpState *state = &dump_state_global;
1905     result->status = qatomic_read(&state->status);
1906     /* make sure we are reading status and written_size in order */
1907     smp_rmb();
1908     result->completed = state->written_size;
1909     result->total = state->total_size;
1910     return result;
1911 }
1912 
1913 void qmp_dump_guest_memory(bool paging, const char *file,
1914                            bool has_detach, bool detach,
1915                            bool has_begin, int64_t begin, bool has_length,
1916                            int64_t length, bool has_format,
1917                            DumpGuestMemoryFormat format, Error **errp)
1918 {
1919     ERRP_GUARD();
1920     const char *p;
1921     int fd = -1;
1922     DumpState *s;
1923     bool detach_p = false;
1924 
1925     if (runstate_check(RUN_STATE_INMIGRATE)) {
1926         error_setg(errp, "Dump not allowed during incoming migration.");
1927         return;
1928     }
1929 
1930     /* if there is a dump in background, we should wait until the dump
1931      * finished */
1932     if (qemu_system_dump_in_progress()) {
1933         error_setg(errp, "There is a dump in process, please wait.");
1934         return;
1935     }
1936 
1937     /*
1938      * kdump-compressed format need the whole memory dumped, so paging or
1939      * filter is not supported here.
1940      */
1941     if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
1942         (paging || has_begin || has_length)) {
1943         error_setg(errp, "kdump-compressed format doesn't support paging or "
1944                          "filter");
1945         return;
1946     }
1947     if (has_begin && !has_length) {
1948         error_setg(errp, QERR_MISSING_PARAMETER, "length");
1949         return;
1950     }
1951     if (!has_begin && has_length) {
1952         error_setg(errp, QERR_MISSING_PARAMETER, "begin");
1953         return;
1954     }
1955     if (has_detach) {
1956         detach_p = detach;
1957     }
1958 
1959     /* check whether lzo/snappy is supported */
1960 #ifndef CONFIG_LZO
1961     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
1962         error_setg(errp, "kdump-lzo is not available now");
1963         return;
1964     }
1965 #endif
1966 
1967 #ifndef CONFIG_SNAPPY
1968     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
1969         error_setg(errp, "kdump-snappy is not available now");
1970         return;
1971     }
1972 #endif
1973 
1974 #ifndef TARGET_X86_64
1975     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
1976         error_setg(errp, "Windows dump is only available for x86-64");
1977         return;
1978     }
1979 #endif
1980 
1981 #if !defined(WIN32)
1982     if (strstart(file, "fd:", &p)) {
1983         fd = monitor_get_fd(monitor_cur(), p, errp);
1984         if (fd == -1) {
1985             return;
1986         }
1987     }
1988 #endif
1989 
1990     if  (strstart(file, "file:", &p)) {
1991         fd = qemu_open_old(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
1992         if (fd < 0) {
1993             error_setg_file_open(errp, errno, p);
1994             return;
1995         }
1996     }
1997 
1998     if (fd == -1) {
1999         error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
2000         return;
2001     }
2002 
2003     if (!dump_migration_blocker) {
2004         error_setg(&dump_migration_blocker,
2005                    "Live migration disabled: dump-guest-memory in progress");
2006     }
2007 
2008     /*
2009      * Allows even for -only-migratable, but forbid migration during the
2010      * process of dump guest memory.
2011      */
2012     if (migrate_add_blocker_internal(dump_migration_blocker, errp)) {
2013         /* Remember to release the fd before passing it over to dump state */
2014         close(fd);
2015         return;
2016     }
2017 
2018     s = &dump_state_global;
2019     dump_state_prepare(s);
2020 
2021     dump_init(s, fd, has_format, format, paging, has_begin,
2022               begin, length, errp);
2023     if (*errp) {
2024         qatomic_set(&s->status, DUMP_STATUS_FAILED);
2025         return;
2026     }
2027 
2028     if (detach_p) {
2029         /* detached dump */
2030         s->detached = true;
2031         qemu_thread_create(&s->dump_thread, "dump_thread", dump_thread,
2032                            s, QEMU_THREAD_DETACHED);
2033     } else {
2034         /* sync dump */
2035         dump_process(s, errp);
2036     }
2037 }
2038 
2039 DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
2040 {
2041     DumpGuestMemoryCapability *cap =
2042                                   g_new0(DumpGuestMemoryCapability, 1);
2043     DumpGuestMemoryFormatList **tail = &cap->formats;
2044 
2045     /* elf is always available */
2046     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_ELF);
2047 
2048     /* kdump-zlib is always available */
2049     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB);
2050 
2051     /* add new item if kdump-lzo is available */
2052 #ifdef CONFIG_LZO
2053     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO);
2054 #endif
2055 
2056     /* add new item if kdump-snappy is available */
2057 #ifdef CONFIG_SNAPPY
2058     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
2059 #endif
2060 
2061     /* Windows dump is available only if target is x86_64 */
2062 #ifdef TARGET_X86_64
2063     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
2064 #endif
2065 
2066     return cap;
2067 }
2068