xref: /openbmc/qemu/dump/dump.c (revision 919a0423d8cbdb99e31a9a9d5c49e6e364ddf160)
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      g_array_unref(s->string_table_buf);
107      s->guest_note = NULL;
108      if (s->resume) {
109          if (s->detached) {
110              qemu_mutex_lock_iothread();
111          }
112          vm_start();
113          if (s->detached) {
114              qemu_mutex_unlock_iothread();
115          }
116      }
117      migrate_del_blocker(dump_migration_blocker);
118  
119      return 0;
120  }
121  
122  static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
123  {
124      DumpState *s = opaque;
125      size_t written_size;
126  
127      written_size = qemu_write_full(s->fd, buf, size);
128      if (written_size != size) {
129          return -errno;
130      }
131  
132      return 0;
133  }
134  
135  static void prepare_elf64_header(DumpState *s, Elf64_Ehdr *elf_header)
136  {
137      /*
138       * phnum in the elf header is 16 bit, if we have more segments we
139       * set phnum to PN_XNUM and write the real number of segments to a
140       * special section.
141       */
142      uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
143  
144      memset(elf_header, 0, sizeof(Elf64_Ehdr));
145      memcpy(elf_header, ELFMAG, SELFMAG);
146      elf_header->e_ident[EI_CLASS] = ELFCLASS64;
147      elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
148      elf_header->e_ident[EI_VERSION] = EV_CURRENT;
149      elf_header->e_type = cpu_to_dump16(s, ET_CORE);
150      elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
151      elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
152      elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
153      elf_header->e_phoff = cpu_to_dump64(s, s->phdr_offset);
154      elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
155      elf_header->e_phnum = cpu_to_dump16(s, phnum);
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      elf_header->e_shstrndx = cpu_to_dump16(s, s->shdr_num - 1);
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      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      elf_header->e_shstrndx = cpu_to_dump16(s, s->shdr_num - 1);
187  }
188  
189  static void write_elf_header(DumpState *s, Error **errp)
190  {
191      Elf32_Ehdr elf32_header;
192      Elf64_Ehdr elf64_header;
193      size_t header_size;
194      void *header_ptr;
195      int ret;
196  
197      /* The NULL header and the shstrtab are always defined */
198      assert(s->shdr_num >= 2);
199      if (dump_is_64bit(s)) {
200          prepare_elf64_header(s, &elf64_header);
201          header_size = sizeof(elf64_header);
202          header_ptr = &elf64_header;
203      } else {
204          prepare_elf32_header(s, &elf32_header);
205          header_size = sizeof(elf32_header);
206          header_ptr = &elf32_header;
207      }
208  
209      ret = fd_write_vmcore(header_ptr, header_size, s);
210      if (ret < 0) {
211          error_setg_errno(errp, -ret, "dump: failed to write elf header");
212      }
213  }
214  
215  static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
216                               int phdr_index, hwaddr offset,
217                               hwaddr filesz, Error **errp)
218  {
219      Elf64_Phdr phdr;
220      int ret;
221  
222      memset(&phdr, 0, sizeof(Elf64_Phdr));
223      phdr.p_type = cpu_to_dump32(s, PT_LOAD);
224      phdr.p_offset = cpu_to_dump64(s, offset);
225      phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
226      phdr.p_filesz = cpu_to_dump64(s, filesz);
227      phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
228      phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
229  
230      assert(memory_mapping->length >= filesz);
231  
232      ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
233      if (ret < 0) {
234          error_setg_errno(errp, -ret,
235                           "dump: failed to write program header table");
236      }
237  }
238  
239  static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
240                               int phdr_index, hwaddr offset,
241                               hwaddr filesz, Error **errp)
242  {
243      Elf32_Phdr phdr;
244      int ret;
245  
246      memset(&phdr, 0, sizeof(Elf32_Phdr));
247      phdr.p_type = cpu_to_dump32(s, PT_LOAD);
248      phdr.p_offset = cpu_to_dump32(s, offset);
249      phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
250      phdr.p_filesz = cpu_to_dump32(s, filesz);
251      phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
252      phdr.p_vaddr =
253          cpu_to_dump32(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
254  
255      assert(memory_mapping->length >= filesz);
256  
257      ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
258      if (ret < 0) {
259          error_setg_errno(errp, -ret,
260                           "dump: failed to write program header table");
261      }
262  }
263  
264  static void prepare_elf64_phdr_note(DumpState *s, Elf64_Phdr *phdr)
265  {
266      memset(phdr, 0, sizeof(*phdr));
267      phdr->p_type = cpu_to_dump32(s, PT_NOTE);
268      phdr->p_offset = cpu_to_dump64(s, s->note_offset);
269      phdr->p_paddr = 0;
270      phdr->p_filesz = cpu_to_dump64(s, s->note_size);
271      phdr->p_memsz = cpu_to_dump64(s, s->note_size);
272      phdr->p_vaddr = 0;
273  }
274  
275  static inline int cpu_index(CPUState *cpu)
276  {
277      return cpu->cpu_index + 1;
278  }
279  
280  static void write_guest_note(WriteCoreDumpFunction f, DumpState *s,
281                               Error **errp)
282  {
283      int ret;
284  
285      if (s->guest_note) {
286          ret = f(s->guest_note, s->guest_note_size, s);
287          if (ret < 0) {
288              error_setg(errp, "dump: failed to write guest note");
289          }
290      }
291  }
292  
293  static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
294                                Error **errp)
295  {
296      CPUState *cpu;
297      int ret;
298      int id;
299  
300      CPU_FOREACH(cpu) {
301          id = cpu_index(cpu);
302          ret = cpu_write_elf64_note(f, cpu, id, s);
303          if (ret < 0) {
304              error_setg(errp, "dump: failed to write elf notes");
305              return;
306          }
307      }
308  
309      CPU_FOREACH(cpu) {
310          ret = cpu_write_elf64_qemunote(f, cpu, s);
311          if (ret < 0) {
312              error_setg(errp, "dump: failed to write CPU status");
313              return;
314          }
315      }
316  
317      write_guest_note(f, s, errp);
318  }
319  
320  static void prepare_elf32_phdr_note(DumpState *s, Elf32_Phdr *phdr)
321  {
322      memset(phdr, 0, sizeof(*phdr));
323      phdr->p_type = cpu_to_dump32(s, PT_NOTE);
324      phdr->p_offset = cpu_to_dump32(s, s->note_offset);
325      phdr->p_paddr = 0;
326      phdr->p_filesz = cpu_to_dump32(s, s->note_size);
327      phdr->p_memsz = cpu_to_dump32(s, s->note_size);
328      phdr->p_vaddr = 0;
329  }
330  
331  static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
332                                Error **errp)
333  {
334      CPUState *cpu;
335      int ret;
336      int id;
337  
338      CPU_FOREACH(cpu) {
339          id = cpu_index(cpu);
340          ret = cpu_write_elf32_note(f, cpu, id, s);
341          if (ret < 0) {
342              error_setg(errp, "dump: failed to write elf notes");
343              return;
344          }
345      }
346  
347      CPU_FOREACH(cpu) {
348          ret = cpu_write_elf32_qemunote(f, cpu, s);
349          if (ret < 0) {
350              error_setg(errp, "dump: failed to write CPU status");
351              return;
352          }
353      }
354  
355      write_guest_note(f, s, errp);
356  }
357  
358  static void write_elf_phdr_note(DumpState *s, Error **errp)
359  {
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 prepare_elf_section_hdr_zero(DumpState *s)
384  {
385      if (dump_is_64bit(s)) {
386          Elf64_Shdr *shdr64 = s->elf_section_hdrs;
387  
388          shdr64->sh_info = cpu_to_dump32(s, s->phdr_num);
389      } else {
390          Elf32_Shdr *shdr32 = s->elf_section_hdrs;
391  
392          shdr32->sh_info = cpu_to_dump32(s, s->phdr_num);
393      }
394  }
395  
396  static void prepare_elf_section_hdr_string(DumpState *s, void *buff)
397  {
398      uint64_t index = s->string_table_buf->len;
399      const char strtab[] = ".shstrtab";
400      Elf32_Shdr shdr32 = {};
401      Elf64_Shdr shdr64 = {};
402      int shdr_size;
403      void *shdr;
404  
405      g_array_append_vals(s->string_table_buf, strtab, sizeof(strtab));
406      if (dump_is_64bit(s)) {
407          shdr_size = sizeof(Elf64_Shdr);
408          shdr64.sh_type = SHT_STRTAB;
409          shdr64.sh_offset = s->section_offset + s->elf_section_data_size;
410          shdr64.sh_name = index;
411          shdr64.sh_size = s->string_table_buf->len;
412          shdr = &shdr64;
413      } else {
414          shdr_size = sizeof(Elf32_Shdr);
415          shdr32.sh_type = SHT_STRTAB;
416          shdr32.sh_offset = s->section_offset + s->elf_section_data_size;
417          shdr32.sh_name = index;
418          shdr32.sh_size = s->string_table_buf->len;
419          shdr = &shdr32;
420      }
421      memcpy(buff, shdr, shdr_size);
422  }
423  
424  static bool prepare_elf_section_hdrs(DumpState *s, Error **errp)
425  {
426      size_t len, sizeof_shdr;
427      void *buff_hdr;
428  
429      /*
430       * Section ordering:
431       * - HDR zero
432       * - Arch section hdrs
433       * - String table hdr
434       */
435      sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
436      len = sizeof_shdr * s->shdr_num;
437      s->elf_section_hdrs = g_malloc0(len);
438      buff_hdr = s->elf_section_hdrs;
439  
440      /*
441       * The first section header is ALWAYS a special initial section
442       * header.
443       *
444       * The header should be 0 with one exception being that if
445       * phdr_num is PN_XNUM then the sh_info field contains the real
446       * number of segment entries.
447       *
448       * As we zero allocate the buffer we will only need to modify
449       * sh_info for the PN_XNUM case.
450       */
451      if (s->phdr_num >= PN_XNUM) {
452          prepare_elf_section_hdr_zero(s);
453      }
454      buff_hdr += sizeof_shdr;
455  
456      /* Add architecture defined section headers */
457      if (s->dump_info.arch_sections_write_hdr_fn
458          && s->shdr_num > 2) {
459          buff_hdr += s->dump_info.arch_sections_write_hdr_fn(s, buff_hdr);
460  
461          if (s->shdr_num >= SHN_LORESERVE) {
462              error_setg_errno(errp, EINVAL,
463                               "dump: too many architecture defined sections");
464              return false;
465          }
466      }
467  
468      /*
469       * String table is the last section since strings are added via
470       * arch_sections_write_hdr().
471       */
472      prepare_elf_section_hdr_string(s, buff_hdr);
473      return true;
474  }
475  
476  static void write_elf_section_headers(DumpState *s, Error **errp)
477  {
478      size_t sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
479      int ret;
480  
481      if (!prepare_elf_section_hdrs(s, errp)) {
482          return;
483      }
484  
485      ret = fd_write_vmcore(s->elf_section_hdrs, s->shdr_num * sizeof_shdr, s);
486      if (ret < 0) {
487          error_setg_errno(errp, -ret, "dump: failed to write section headers");
488      }
489  
490      g_free(s->elf_section_hdrs);
491  }
492  
493  static void write_elf_sections(DumpState *s, Error **errp)
494  {
495      int ret;
496  
497      if (s->elf_section_data_size) {
498          /* Write architecture section data */
499          ret = fd_write_vmcore(s->elf_section_data,
500                                s->elf_section_data_size, s);
501          if (ret < 0) {
502              error_setg_errno(errp, -ret,
503                               "dump: failed to write architecture section data");
504              return;
505          }
506      }
507  
508      /* Write string table */
509      ret = fd_write_vmcore(s->string_table_buf->data,
510                            s->string_table_buf->len, s);
511      if (ret < 0) {
512          error_setg_errno(errp, -ret, "dump: failed to write string table data");
513      }
514  }
515  
516  static void write_data(DumpState *s, void *buf, int length, Error **errp)
517  {
518      int ret;
519  
520      ret = fd_write_vmcore(buf, length, s);
521      if (ret < 0) {
522          error_setg_errno(errp, -ret, "dump: failed to save memory");
523      } else {
524          s->written_size += length;
525      }
526  }
527  
528  /* write the memory to vmcore. 1 page per I/O. */
529  static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
530                           int64_t size, Error **errp)
531  {
532      ERRP_GUARD();
533      int64_t i;
534  
535      for (i = 0; i < size / s->dump_info.page_size; i++) {
536          write_data(s, block->host_addr + start + i * s->dump_info.page_size,
537                     s->dump_info.page_size, errp);
538          if (*errp) {
539              return;
540          }
541      }
542  
543      if ((size % s->dump_info.page_size) != 0) {
544          write_data(s, block->host_addr + start + i * s->dump_info.page_size,
545                     size % s->dump_info.page_size, errp);
546          if (*errp) {
547              return;
548          }
549      }
550  }
551  
552  /* get the memory's offset and size in the vmcore */
553  static void get_offset_range(hwaddr phys_addr,
554                               ram_addr_t mapping_length,
555                               DumpState *s,
556                               hwaddr *p_offset,
557                               hwaddr *p_filesz)
558  {
559      GuestPhysBlock *block;
560      hwaddr offset = s->memory_offset;
561      int64_t size_in_block, start;
562  
563      /* When the memory is not stored into vmcore, offset will be -1 */
564      *p_offset = -1;
565      *p_filesz = 0;
566  
567      if (dump_has_filter(s)) {
568          if (phys_addr < s->filter_area_begin ||
569              phys_addr >= s->filter_area_begin + s->filter_area_length) {
570              return;
571          }
572      }
573  
574      QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
575          if (dump_has_filter(s)) {
576              if (block->target_start >= s->filter_area_begin + s->filter_area_length ||
577                  block->target_end <= s->filter_area_begin) {
578                  /* This block is out of the range */
579                  continue;
580              }
581  
582              if (s->filter_area_begin <= block->target_start) {
583                  start = block->target_start;
584              } else {
585                  start = s->filter_area_begin;
586              }
587  
588              size_in_block = block->target_end - start;
589              if (s->filter_area_begin + s->filter_area_length < block->target_end) {
590                  size_in_block -= block->target_end - (s->filter_area_begin + s->filter_area_length);
591              }
592          } else {
593              start = block->target_start;
594              size_in_block = block->target_end - block->target_start;
595          }
596  
597          if (phys_addr >= start && phys_addr < start + size_in_block) {
598              *p_offset = phys_addr - start + offset;
599  
600              /* The offset range mapped from the vmcore file must not spill over
601               * the GuestPhysBlock, clamp it. The rest of the mapping will be
602               * zero-filled in memory at load time; see
603               * <http://refspecs.linuxbase.org/elf/gabi4+/ch5.pheader.html>.
604               */
605              *p_filesz = phys_addr + mapping_length <= start + size_in_block ?
606                          mapping_length :
607                          size_in_block - (phys_addr - start);
608              return;
609          }
610  
611          offset += size_in_block;
612      }
613  }
614  
615  static void write_elf_phdr_loads(DumpState *s, Error **errp)
616  {
617      ERRP_GUARD();
618      hwaddr offset, filesz;
619      MemoryMapping *memory_mapping;
620      uint32_t phdr_index = 1;
621  
622      QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
623          get_offset_range(memory_mapping->phys_addr,
624                           memory_mapping->length,
625                           s, &offset, &filesz);
626          if (dump_is_64bit(s)) {
627              write_elf64_load(s, memory_mapping, phdr_index++, offset,
628                               filesz, errp);
629          } else {
630              write_elf32_load(s, memory_mapping, phdr_index++, offset,
631                               filesz, errp);
632          }
633  
634          if (*errp) {
635              return;
636          }
637  
638          if (phdr_index >= s->phdr_num) {
639              break;
640          }
641      }
642  }
643  
644  static void write_elf_notes(DumpState *s, Error **errp)
645  {
646      if (dump_is_64bit(s)) {
647          write_elf64_notes(fd_write_vmcore, s, errp);
648      } else {
649          write_elf32_notes(fd_write_vmcore, s, errp);
650      }
651  }
652  
653  /* write elf header, PT_NOTE and elf note to vmcore. */
654  static void dump_begin(DumpState *s, Error **errp)
655  {
656      ERRP_GUARD();
657  
658      /*
659       * the vmcore's format is:
660       *   --------------
661       *   |  elf header |
662       *   --------------
663       *   |  sctn_hdr   |
664       *   --------------
665       *   |  PT_NOTE    |
666       *   --------------
667       *   |  PT_LOAD    |
668       *   --------------
669       *   |  ......     |
670       *   --------------
671       *   |  PT_LOAD    |
672       *   --------------
673       *   |  elf note   |
674       *   --------------
675       *   |  memory     |
676       *   --------------
677       *
678       * we only know where the memory is saved after we write elf note into
679       * vmcore.
680       */
681  
682      /* write elf header to vmcore */
683      write_elf_header(s, errp);
684      if (*errp) {
685          return;
686      }
687  
688      /* write section headers to vmcore */
689      write_elf_section_headers(s, errp);
690      if (*errp) {
691          return;
692      }
693  
694      /* write PT_NOTE to vmcore */
695      write_elf_phdr_note(s, errp);
696      if (*errp) {
697          return;
698      }
699  
700      /* write all PT_LOADs to vmcore */
701      write_elf_phdr_loads(s, errp);
702      if (*errp) {
703          return;
704      }
705  
706      /* write notes to vmcore */
707      write_elf_notes(s, errp);
708  }
709  
710  int64_t dump_filtered_memblock_size(GuestPhysBlock *block,
711                                      int64_t filter_area_start,
712                                      int64_t filter_area_length)
713  {
714      int64_t size, left, right;
715  
716      /* No filter, return full size */
717      if (!filter_area_length) {
718          return block->target_end - block->target_start;
719      }
720  
721      /* calculate the overlapped region. */
722      left = MAX(filter_area_start, block->target_start);
723      right = MIN(filter_area_start + filter_area_length, block->target_end);
724      size = right - left;
725      size = size > 0 ? size : 0;
726  
727      return size;
728  }
729  
730  int64_t dump_filtered_memblock_start(GuestPhysBlock *block,
731                                       int64_t filter_area_start,
732                                       int64_t filter_area_length)
733  {
734      if (filter_area_length) {
735          /* return -1 if the block is not within filter area */
736          if (block->target_start >= filter_area_start + filter_area_length ||
737              block->target_end <= filter_area_start) {
738              return -1;
739          }
740  
741          if (filter_area_start > block->target_start) {
742              return filter_area_start - block->target_start;
743          }
744      }
745  
746      return 0;
747  }
748  
749  /* write all memory to vmcore */
750  static void dump_iterate(DumpState *s, Error **errp)
751  {
752      ERRP_GUARD();
753      GuestPhysBlock *block;
754      int64_t memblock_size, memblock_start;
755  
756      QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
757          memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin, s->filter_area_length);
758          if (memblock_start == -1) {
759              continue;
760          }
761  
762          memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin, s->filter_area_length);
763  
764          /* Write the memory to file */
765          write_memory(s, block, memblock_start, memblock_size, errp);
766          if (*errp) {
767              return;
768          }
769      }
770  }
771  
772  static void dump_end(DumpState *s, Error **errp)
773  {
774      int rc;
775  
776      if (s->elf_section_data_size) {
777          s->elf_section_data = g_malloc0(s->elf_section_data_size);
778      }
779  
780      /* Adds the architecture defined section data to s->elf_section_data  */
781      if (s->dump_info.arch_sections_write_fn &&
782          s->elf_section_data_size) {
783          rc = s->dump_info.arch_sections_write_fn(s, s->elf_section_data);
784          if (rc) {
785              error_setg_errno(errp, rc,
786                               "dump: failed to get arch section data");
787              g_free(s->elf_section_data);
788              return;
789          }
790      }
791  
792      /* write sections to vmcore */
793      write_elf_sections(s, errp);
794  }
795  
796  static void create_vmcore(DumpState *s, Error **errp)
797  {
798      ERRP_GUARD();
799  
800      dump_begin(s, errp);
801      if (*errp) {
802          return;
803      }
804  
805      /* Iterate over memory and dump it to file */
806      dump_iterate(s, errp);
807      if (*errp) {
808          return;
809      }
810  
811      /* Write the section data */
812      dump_end(s, errp);
813  }
814  
815  static int write_start_flat_header(int fd)
816  {
817      MakedumpfileHeader *mh;
818      int ret = 0;
819  
820      QEMU_BUILD_BUG_ON(sizeof *mh > MAX_SIZE_MDF_HEADER);
821      mh = g_malloc0(MAX_SIZE_MDF_HEADER);
822  
823      memcpy(mh->signature, MAKEDUMPFILE_SIGNATURE,
824             MIN(sizeof mh->signature, sizeof MAKEDUMPFILE_SIGNATURE));
825  
826      mh->type = cpu_to_be64(TYPE_FLAT_HEADER);
827      mh->version = cpu_to_be64(VERSION_FLAT_HEADER);
828  
829      size_t written_size;
830      written_size = qemu_write_full(fd, mh, MAX_SIZE_MDF_HEADER);
831      if (written_size != MAX_SIZE_MDF_HEADER) {
832          ret = -1;
833      }
834  
835      g_free(mh);
836      return ret;
837  }
838  
839  static int write_end_flat_header(int fd)
840  {
841      MakedumpfileDataHeader mdh;
842  
843      mdh.offset = END_FLAG_FLAT_HEADER;
844      mdh.buf_size = END_FLAG_FLAT_HEADER;
845  
846      size_t written_size;
847      written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
848      if (written_size != sizeof(mdh)) {
849          return -1;
850      }
851  
852      return 0;
853  }
854  
855  static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
856  {
857      size_t written_size;
858      MakedumpfileDataHeader mdh;
859  
860      mdh.offset = cpu_to_be64(offset);
861      mdh.buf_size = cpu_to_be64(size);
862  
863      written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
864      if (written_size != sizeof(mdh)) {
865          return -1;
866      }
867  
868      written_size = qemu_write_full(fd, buf, size);
869      if (written_size != size) {
870          return -1;
871      }
872  
873      return 0;
874  }
875  
876  static int buf_write_note(const void *buf, size_t size, void *opaque)
877  {
878      DumpState *s = opaque;
879  
880      /* note_buf is not enough */
881      if (s->note_buf_offset + size > s->note_size) {
882          return -1;
883      }
884  
885      memcpy(s->note_buf + s->note_buf_offset, buf, size);
886  
887      s->note_buf_offset += size;
888  
889      return 0;
890  }
891  
892  /*
893   * This function retrieves various sizes from an elf header.
894   *
895   * @note has to be a valid ELF note. The return sizes are unmodified
896   * (not padded or rounded up to be multiple of 4).
897   */
898  static void get_note_sizes(DumpState *s, const void *note,
899                             uint64_t *note_head_size,
900                             uint64_t *name_size,
901                             uint64_t *desc_size)
902  {
903      uint64_t note_head_sz;
904      uint64_t name_sz;
905      uint64_t desc_sz;
906  
907      if (dump_is_64bit(s)) {
908          const Elf64_Nhdr *hdr = note;
909          note_head_sz = sizeof(Elf64_Nhdr);
910          name_sz = tswap64(hdr->n_namesz);
911          desc_sz = tswap64(hdr->n_descsz);
912      } else {
913          const Elf32_Nhdr *hdr = note;
914          note_head_sz = sizeof(Elf32_Nhdr);
915          name_sz = tswap32(hdr->n_namesz);
916          desc_sz = tswap32(hdr->n_descsz);
917      }
918  
919      if (note_head_size) {
920          *note_head_size = note_head_sz;
921      }
922      if (name_size) {
923          *name_size = name_sz;
924      }
925      if (desc_size) {
926          *desc_size = desc_sz;
927      }
928  }
929  
930  static bool note_name_equal(DumpState *s,
931                              const uint8_t *note, const char *name)
932  {
933      int len = strlen(name) + 1;
934      uint64_t head_size, name_size;
935  
936      get_note_sizes(s, note, &head_size, &name_size, NULL);
937      head_size = ROUND_UP(head_size, 4);
938  
939      return name_size == len && memcmp(note + head_size, name, len) == 0;
940  }
941  
942  /* write common header, sub header and elf note to vmcore */
943  static void create_header32(DumpState *s, Error **errp)
944  {
945      ERRP_GUARD();
946      DiskDumpHeader32 *dh = NULL;
947      KdumpSubHeader32 *kh = NULL;
948      size_t size;
949      uint32_t block_size;
950      uint32_t sub_hdr_size;
951      uint32_t bitmap_blocks;
952      uint32_t status = 0;
953      uint64_t offset_note;
954  
955      /* write common header, the version of kdump-compressed format is 6th */
956      size = sizeof(DiskDumpHeader32);
957      dh = g_malloc0(size);
958  
959      memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
960      dh->header_version = cpu_to_dump32(s, 6);
961      block_size = s->dump_info.page_size;
962      dh->block_size = cpu_to_dump32(s, block_size);
963      sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
964      sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
965      dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
966      /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
967      dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
968      dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
969      bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
970      dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
971      strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
972  
973      if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
974          status |= DUMP_DH_COMPRESSED_ZLIB;
975      }
976  #ifdef CONFIG_LZO
977      if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
978          status |= DUMP_DH_COMPRESSED_LZO;
979      }
980  #endif
981  #ifdef CONFIG_SNAPPY
982      if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
983          status |= DUMP_DH_COMPRESSED_SNAPPY;
984      }
985  #endif
986      dh->status = cpu_to_dump32(s, status);
987  
988      if (write_buffer(s->fd, 0, dh, size) < 0) {
989          error_setg(errp, "dump: failed to write disk dump header");
990          goto out;
991      }
992  
993      /* write sub header */
994      size = sizeof(KdumpSubHeader32);
995      kh = g_malloc0(size);
996  
997      /* 64bit max_mapnr_64 */
998      kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
999      kh->phys_base = cpu_to_dump32(s, s->dump_info.phys_base);
1000      kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
1001  
1002      offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
1003      if (s->guest_note &&
1004          note_name_equal(s, s->guest_note, "VMCOREINFO")) {
1005          uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
1006  
1007          get_note_sizes(s, s->guest_note,
1008                         &hsize, &name_size, &size_vmcoreinfo_desc);
1009          offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
1010              (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
1011          kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
1012          kh->size_vmcoreinfo = cpu_to_dump32(s, size_vmcoreinfo_desc);
1013      }
1014  
1015      kh->offset_note = cpu_to_dump64(s, offset_note);
1016      kh->note_size = cpu_to_dump32(s, s->note_size);
1017  
1018      if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
1019                       block_size, kh, size) < 0) {
1020          error_setg(errp, "dump: failed to write kdump sub header");
1021          goto out;
1022      }
1023  
1024      /* write note */
1025      s->note_buf = g_malloc0(s->note_size);
1026      s->note_buf_offset = 0;
1027  
1028      /* use s->note_buf to store notes temporarily */
1029      write_elf32_notes(buf_write_note, s, errp);
1030      if (*errp) {
1031          goto out;
1032      }
1033      if (write_buffer(s->fd, offset_note, s->note_buf,
1034                       s->note_size) < 0) {
1035          error_setg(errp, "dump: failed to write notes");
1036          goto out;
1037      }
1038  
1039      /* get offset of dump_bitmap */
1040      s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
1041                               block_size;
1042  
1043      /* get offset of page */
1044      s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
1045                       block_size;
1046  
1047  out:
1048      g_free(dh);
1049      g_free(kh);
1050      g_free(s->note_buf);
1051  }
1052  
1053  /* write common header, sub header and elf note to vmcore */
1054  static void create_header64(DumpState *s, Error **errp)
1055  {
1056      ERRP_GUARD();
1057      DiskDumpHeader64 *dh = NULL;
1058      KdumpSubHeader64 *kh = NULL;
1059      size_t size;
1060      uint32_t block_size;
1061      uint32_t sub_hdr_size;
1062      uint32_t bitmap_blocks;
1063      uint32_t status = 0;
1064      uint64_t offset_note;
1065  
1066      /* write common header, the version of kdump-compressed format is 6th */
1067      size = sizeof(DiskDumpHeader64);
1068      dh = g_malloc0(size);
1069  
1070      memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
1071      dh->header_version = cpu_to_dump32(s, 6);
1072      block_size = s->dump_info.page_size;
1073      dh->block_size = cpu_to_dump32(s, block_size);
1074      sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
1075      sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
1076      dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
1077      /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
1078      dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
1079      dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
1080      bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
1081      dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
1082      strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
1083  
1084      if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
1085          status |= DUMP_DH_COMPRESSED_ZLIB;
1086      }
1087  #ifdef CONFIG_LZO
1088      if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
1089          status |= DUMP_DH_COMPRESSED_LZO;
1090      }
1091  #endif
1092  #ifdef CONFIG_SNAPPY
1093      if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
1094          status |= DUMP_DH_COMPRESSED_SNAPPY;
1095      }
1096  #endif
1097      dh->status = cpu_to_dump32(s, status);
1098  
1099      if (write_buffer(s->fd, 0, dh, size) < 0) {
1100          error_setg(errp, "dump: failed to write disk dump header");
1101          goto out;
1102      }
1103  
1104      /* write sub header */
1105      size = sizeof(KdumpSubHeader64);
1106      kh = g_malloc0(size);
1107  
1108      /* 64bit max_mapnr_64 */
1109      kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
1110      kh->phys_base = cpu_to_dump64(s, s->dump_info.phys_base);
1111      kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
1112  
1113      offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
1114      if (s->guest_note &&
1115          note_name_equal(s, s->guest_note, "VMCOREINFO")) {
1116          uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
1117  
1118          get_note_sizes(s, s->guest_note,
1119                         &hsize, &name_size, &size_vmcoreinfo_desc);
1120          offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
1121              (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
1122          kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
1123          kh->size_vmcoreinfo = cpu_to_dump64(s, size_vmcoreinfo_desc);
1124      }
1125  
1126      kh->offset_note = cpu_to_dump64(s, offset_note);
1127      kh->note_size = cpu_to_dump64(s, s->note_size);
1128  
1129      if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
1130                       block_size, kh, size) < 0) {
1131          error_setg(errp, "dump: failed to write kdump sub header");
1132          goto out;
1133      }
1134  
1135      /* write note */
1136      s->note_buf = g_malloc0(s->note_size);
1137      s->note_buf_offset = 0;
1138  
1139      /* use s->note_buf to store notes temporarily */
1140      write_elf64_notes(buf_write_note, s, errp);
1141      if (*errp) {
1142          goto out;
1143      }
1144  
1145      if (write_buffer(s->fd, offset_note, s->note_buf,
1146                       s->note_size) < 0) {
1147          error_setg(errp, "dump: failed to write notes");
1148          goto out;
1149      }
1150  
1151      /* get offset of dump_bitmap */
1152      s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
1153                               block_size;
1154  
1155      /* get offset of page */
1156      s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
1157                       block_size;
1158  
1159  out:
1160      g_free(dh);
1161      g_free(kh);
1162      g_free(s->note_buf);
1163  }
1164  
1165  static void write_dump_header(DumpState *s, Error **errp)
1166  {
1167      if (dump_is_64bit(s)) {
1168          create_header64(s, errp);
1169      } else {
1170          create_header32(s, errp);
1171      }
1172  }
1173  
1174  static size_t dump_bitmap_get_bufsize(DumpState *s)
1175  {
1176      return s->dump_info.page_size;
1177  }
1178  
1179  /*
1180   * set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
1181   * rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
1182   * set_dump_bitmap will always leave the recently set bit un-sync. And setting
1183   * (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
1184   * vmcore, ie. synchronizing un-sync bit into vmcore.
1185   */
1186  static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
1187                             uint8_t *buf, DumpState *s)
1188  {
1189      off_t old_offset, new_offset;
1190      off_t offset_bitmap1, offset_bitmap2;
1191      uint32_t byte, bit;
1192      size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
1193      size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
1194  
1195      /* should not set the previous place */
1196      assert(last_pfn <= pfn);
1197  
1198      /*
1199       * if the bit needed to be set is not cached in buf, flush the data in buf
1200       * to vmcore firstly.
1201       * making new_offset be bigger than old_offset can also sync remained data
1202       * into vmcore.
1203       */
1204      old_offset = bitmap_bufsize * (last_pfn / bits_per_buf);
1205      new_offset = bitmap_bufsize * (pfn / bits_per_buf);
1206  
1207      while (old_offset < new_offset) {
1208          /* calculate the offset and write dump_bitmap */
1209          offset_bitmap1 = s->offset_dump_bitmap + old_offset;
1210          if (write_buffer(s->fd, offset_bitmap1, buf,
1211                           bitmap_bufsize) < 0) {
1212              return -1;
1213          }
1214  
1215          /* dump level 1 is chosen, so 1st and 2nd bitmap are same */
1216          offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
1217                           old_offset;
1218          if (write_buffer(s->fd, offset_bitmap2, buf,
1219                           bitmap_bufsize) < 0) {
1220              return -1;
1221          }
1222  
1223          memset(buf, 0, bitmap_bufsize);
1224          old_offset += bitmap_bufsize;
1225      }
1226  
1227      /* get the exact place of the bit in the buf, and set it */
1228      byte = (pfn % bits_per_buf) / CHAR_BIT;
1229      bit = (pfn % bits_per_buf) % CHAR_BIT;
1230      if (value) {
1231          buf[byte] |= 1u << bit;
1232      } else {
1233          buf[byte] &= ~(1u << bit);
1234      }
1235  
1236      return 0;
1237  }
1238  
1239  static uint64_t dump_paddr_to_pfn(DumpState *s, uint64_t addr)
1240  {
1241      int target_page_shift = ctz32(s->dump_info.page_size);
1242  
1243      return (addr >> target_page_shift) - ARCH_PFN_OFFSET;
1244  }
1245  
1246  static uint64_t dump_pfn_to_paddr(DumpState *s, uint64_t pfn)
1247  {
1248      int target_page_shift = ctz32(s->dump_info.page_size);
1249  
1250      return (pfn + ARCH_PFN_OFFSET) << target_page_shift;
1251  }
1252  
1253  /*
1254   * Return the page frame number and the page content in *bufptr. bufptr can be
1255   * NULL. If not NULL, *bufptr must contains a target page size of pre-allocated
1256   * memory. This is not necessarily the memory returned.
1257   */
1258  static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
1259                            uint8_t **bufptr, DumpState *s)
1260  {
1261      GuestPhysBlock *block = *blockptr;
1262      uint32_t page_size = s->dump_info.page_size;
1263      uint8_t *buf = NULL, *hbuf;
1264      hwaddr addr;
1265  
1266      /* block == NULL means the start of the iteration */
1267      if (!block) {
1268          block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
1269          *blockptr = block;
1270          addr = block->target_start;
1271          *pfnptr = dump_paddr_to_pfn(s, addr);
1272      } else {
1273          *pfnptr += 1;
1274          addr = dump_pfn_to_paddr(s, *pfnptr);
1275      }
1276      assert(block != NULL);
1277  
1278      while (1) {
1279          if (addr >= block->target_start && addr < block->target_end) {
1280              size_t n = MIN(block->target_end - addr, page_size - addr % page_size);
1281              hbuf = block->host_addr + (addr - block->target_start);
1282              if (!buf) {
1283                  if (n == page_size) {
1284                      /* this is a whole target page, go for it */
1285                      assert(addr % page_size == 0);
1286                      buf = hbuf;
1287                      break;
1288                  } else if (bufptr) {
1289                      assert(*bufptr);
1290                      buf = *bufptr;
1291                      memset(buf, 0, page_size);
1292                  } else {
1293                      return true;
1294                  }
1295              }
1296  
1297              memcpy(buf + addr % page_size, hbuf, n);
1298              addr += n;
1299              if (addr % page_size == 0) {
1300                  /* we filled up the page */
1301                  break;
1302              }
1303          } else {
1304              /* the next page is in the next block */
1305              *blockptr = block = QTAILQ_NEXT(block, next);
1306              if (!block) {
1307                  break;
1308              }
1309  
1310              addr = block->target_start;
1311              /* are we still in the same page? */
1312              if (dump_paddr_to_pfn(s, addr) != *pfnptr) {
1313                  if (buf) {
1314                      /* no, but we already filled something earlier, return it */
1315                      break;
1316                  } else {
1317                      /* else continue from there */
1318                      *pfnptr = dump_paddr_to_pfn(s, addr);
1319                  }
1320              }
1321          }
1322      }
1323  
1324      if (bufptr) {
1325          *bufptr = buf;
1326      }
1327  
1328      return buf != NULL;
1329  }
1330  
1331  static void write_dump_bitmap(DumpState *s, Error **errp)
1332  {
1333      int ret = 0;
1334      uint64_t last_pfn, pfn;
1335      void *dump_bitmap_buf;
1336      size_t num_dumpable;
1337      GuestPhysBlock *block_iter = NULL;
1338      size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
1339      size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
1340  
1341      /* dump_bitmap_buf is used to store dump_bitmap temporarily */
1342      dump_bitmap_buf = g_malloc0(bitmap_bufsize);
1343  
1344      num_dumpable = 0;
1345      last_pfn = 0;
1346  
1347      /*
1348       * exam memory page by page, and set the bit in dump_bitmap corresponded
1349       * to the existing page.
1350       */
1351      while (get_next_page(&block_iter, &pfn, NULL, s)) {
1352          ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
1353          if (ret < 0) {
1354              error_setg(errp, "dump: failed to set dump_bitmap");
1355              goto out;
1356          }
1357  
1358          last_pfn = pfn;
1359          num_dumpable++;
1360      }
1361  
1362      /*
1363       * set_dump_bitmap will always leave the recently set bit un-sync. Here we
1364       * set the remaining bits from last_pfn to the end of the bitmap buffer to
1365       * 0. With those set, the un-sync bit will be synchronized into the vmcore.
1366       */
1367      if (num_dumpable > 0) {
1368          ret = set_dump_bitmap(last_pfn, last_pfn + bits_per_buf, false,
1369                                dump_bitmap_buf, s);
1370          if (ret < 0) {
1371              error_setg(errp, "dump: failed to sync dump_bitmap");
1372              goto out;
1373          }
1374      }
1375  
1376      /* number of dumpable pages that will be dumped later */
1377      s->num_dumpable = num_dumpable;
1378  
1379  out:
1380      g_free(dump_bitmap_buf);
1381  }
1382  
1383  static void prepare_data_cache(DataCache *data_cache, DumpState *s,
1384                                 off_t offset)
1385  {
1386      data_cache->fd = s->fd;
1387      data_cache->data_size = 0;
1388      data_cache->buf_size = 4 * dump_bitmap_get_bufsize(s);
1389      data_cache->buf = g_malloc0(data_cache->buf_size);
1390      data_cache->offset = offset;
1391  }
1392  
1393  static int write_cache(DataCache *dc, const void *buf, size_t size,
1394                         bool flag_sync)
1395  {
1396      /*
1397       * dc->buf_size should not be less than size, otherwise dc will never be
1398       * enough
1399       */
1400      assert(size <= dc->buf_size);
1401  
1402      /*
1403       * if flag_sync is set, synchronize data in dc->buf into vmcore.
1404       * otherwise check if the space is enough for caching data in buf, if not,
1405       * write the data in dc->buf to dc->fd and reset dc->buf
1406       */
1407      if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
1408          (flag_sync && dc->data_size > 0)) {
1409          if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) {
1410              return -1;
1411          }
1412  
1413          dc->offset += dc->data_size;
1414          dc->data_size = 0;
1415      }
1416  
1417      if (!flag_sync) {
1418          memcpy(dc->buf + dc->data_size, buf, size);
1419          dc->data_size += size;
1420      }
1421  
1422      return 0;
1423  }
1424  
1425  static void free_data_cache(DataCache *data_cache)
1426  {
1427      g_free(data_cache->buf);
1428  }
1429  
1430  static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
1431  {
1432      switch (flag_compress) {
1433      case DUMP_DH_COMPRESSED_ZLIB:
1434          return compressBound(page_size);
1435  
1436      case DUMP_DH_COMPRESSED_LZO:
1437          /*
1438           * LZO will expand incompressible data by a little amount. Please check
1439           * the following URL to see the expansion calculation:
1440           * http://www.oberhumer.com/opensource/lzo/lzofaq.php
1441           */
1442          return page_size + page_size / 16 + 64 + 3;
1443  
1444  #ifdef CONFIG_SNAPPY
1445      case DUMP_DH_COMPRESSED_SNAPPY:
1446          return snappy_max_compressed_length(page_size);
1447  #endif
1448      }
1449      return 0;
1450  }
1451  
1452  static void write_dump_pages(DumpState *s, Error **errp)
1453  {
1454      int ret = 0;
1455      DataCache page_desc, page_data;
1456      size_t len_buf_out, size_out;
1457  #ifdef CONFIG_LZO
1458      lzo_bytep wrkmem = NULL;
1459  #endif
1460      uint8_t *buf_out = NULL;
1461      off_t offset_desc, offset_data;
1462      PageDescriptor pd, pd_zero;
1463      uint8_t *buf;
1464      GuestPhysBlock *block_iter = NULL;
1465      uint64_t pfn_iter;
1466      g_autofree uint8_t *page = NULL;
1467  
1468      /* get offset of page_desc and page_data in dump file */
1469      offset_desc = s->offset_page;
1470      offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
1471  
1472      prepare_data_cache(&page_desc, s, offset_desc);
1473      prepare_data_cache(&page_data, s, offset_data);
1474  
1475      /* prepare buffer to store compressed data */
1476      len_buf_out = get_len_buf_out(s->dump_info.page_size, s->flag_compress);
1477      assert(len_buf_out != 0);
1478  
1479  #ifdef CONFIG_LZO
1480      wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
1481  #endif
1482  
1483      buf_out = g_malloc(len_buf_out);
1484  
1485      /*
1486       * init zero page's page_desc and page_data, because every zero page
1487       * uses the same page_data
1488       */
1489      pd_zero.size = cpu_to_dump32(s, s->dump_info.page_size);
1490      pd_zero.flags = cpu_to_dump32(s, 0);
1491      pd_zero.offset = cpu_to_dump64(s, offset_data);
1492      pd_zero.page_flags = cpu_to_dump64(s, 0);
1493      buf = g_malloc0(s->dump_info.page_size);
1494      ret = write_cache(&page_data, buf, s->dump_info.page_size, false);
1495      g_free(buf);
1496      if (ret < 0) {
1497          error_setg(errp, "dump: failed to write page data (zero page)");
1498          goto out;
1499      }
1500  
1501      offset_data += s->dump_info.page_size;
1502      page = g_malloc(s->dump_info.page_size);
1503  
1504      /*
1505       * dump memory to vmcore page by page. zero page will all be resided in the
1506       * first page of page section
1507       */
1508      for (buf = page; get_next_page(&block_iter, &pfn_iter, &buf, s); buf = page) {
1509          /* check zero page */
1510          if (buffer_is_zero(buf, s->dump_info.page_size)) {
1511              ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
1512                                false);
1513              if (ret < 0) {
1514                  error_setg(errp, "dump: failed to write page desc");
1515                  goto out;
1516              }
1517          } else {
1518              /*
1519               * not zero page, then:
1520               * 1. compress the page
1521               * 2. write the compressed page into the cache of page_data
1522               * 3. get page desc of the compressed page and write it into the
1523               *    cache of page_desc
1524               *
1525               * only one compression format will be used here, for
1526               * s->flag_compress is set. But when compression fails to work,
1527               * we fall back to save in plaintext.
1528               */
1529               size_out = len_buf_out;
1530               if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
1531                      (compress2(buf_out, (uLongf *)&size_out, buf,
1532                                 s->dump_info.page_size, Z_BEST_SPEED) == Z_OK) &&
1533                      (size_out < s->dump_info.page_size)) {
1534                  pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_ZLIB);
1535                  pd.size  = cpu_to_dump32(s, size_out);
1536  
1537                  ret = write_cache(&page_data, buf_out, size_out, false);
1538                  if (ret < 0) {
1539                      error_setg(errp, "dump: failed to write page data");
1540                      goto out;
1541                  }
1542  #ifdef CONFIG_LZO
1543              } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
1544                      (lzo1x_1_compress(buf, s->dump_info.page_size, buf_out,
1545                      (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
1546                      (size_out < s->dump_info.page_size)) {
1547                  pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_LZO);
1548                  pd.size  = cpu_to_dump32(s, size_out);
1549  
1550                  ret = write_cache(&page_data, buf_out, size_out, false);
1551                  if (ret < 0) {
1552                      error_setg(errp, "dump: failed to write page data");
1553                      goto out;
1554                  }
1555  #endif
1556  #ifdef CONFIG_SNAPPY
1557              } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
1558                      (snappy_compress((char *)buf, s->dump_info.page_size,
1559                      (char *)buf_out, &size_out) == SNAPPY_OK) &&
1560                      (size_out < s->dump_info.page_size)) {
1561                  pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_SNAPPY);
1562                  pd.size  = cpu_to_dump32(s, size_out);
1563  
1564                  ret = write_cache(&page_data, buf_out, size_out, false);
1565                  if (ret < 0) {
1566                      error_setg(errp, "dump: failed to write page data");
1567                      goto out;
1568                  }
1569  #endif
1570              } else {
1571                  /*
1572                   * fall back to save in plaintext, size_out should be
1573                   * assigned the target's page size
1574                   */
1575                  pd.flags = cpu_to_dump32(s, 0);
1576                  size_out = s->dump_info.page_size;
1577                  pd.size = cpu_to_dump32(s, size_out);
1578  
1579                  ret = write_cache(&page_data, buf,
1580                                    s->dump_info.page_size, false);
1581                  if (ret < 0) {
1582                      error_setg(errp, "dump: failed to write page data");
1583                      goto out;
1584                  }
1585              }
1586  
1587              /* get and write page desc here */
1588              pd.page_flags = cpu_to_dump64(s, 0);
1589              pd.offset = cpu_to_dump64(s, offset_data);
1590              offset_data += size_out;
1591  
1592              ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
1593              if (ret < 0) {
1594                  error_setg(errp, "dump: failed to write page desc");
1595                  goto out;
1596              }
1597          }
1598          s->written_size += s->dump_info.page_size;
1599      }
1600  
1601      ret = write_cache(&page_desc, NULL, 0, true);
1602      if (ret < 0) {
1603          error_setg(errp, "dump: failed to sync cache for page_desc");
1604          goto out;
1605      }
1606      ret = write_cache(&page_data, NULL, 0, true);
1607      if (ret < 0) {
1608          error_setg(errp, "dump: failed to sync cache for page_data");
1609          goto out;
1610      }
1611  
1612  out:
1613      free_data_cache(&page_desc);
1614      free_data_cache(&page_data);
1615  
1616  #ifdef CONFIG_LZO
1617      g_free(wrkmem);
1618  #endif
1619  
1620      g_free(buf_out);
1621  }
1622  
1623  static void create_kdump_vmcore(DumpState *s, Error **errp)
1624  {
1625      ERRP_GUARD();
1626      int ret;
1627  
1628      /*
1629       * the kdump-compressed format is:
1630       *                                               File offset
1631       *  +------------------------------------------+ 0x0
1632       *  |    main header (struct disk_dump_header) |
1633       *  |------------------------------------------+ block 1
1634       *  |    sub header (struct kdump_sub_header)  |
1635       *  |------------------------------------------+ block 2
1636       *  |            1st-dump_bitmap               |
1637       *  |------------------------------------------+ block 2 + X blocks
1638       *  |            2nd-dump_bitmap               | (aligned by block)
1639       *  |------------------------------------------+ block 2 + 2 * X blocks
1640       *  |  page desc for pfn 0 (struct page_desc)  | (aligned by block)
1641       *  |  page desc for pfn 1 (struct page_desc)  |
1642       *  |                    :                     |
1643       *  |------------------------------------------| (not aligned by block)
1644       *  |         page data (pfn 0)                |
1645       *  |         page data (pfn 1)                |
1646       *  |                    :                     |
1647       *  +------------------------------------------+
1648       */
1649  
1650      ret = write_start_flat_header(s->fd);
1651      if (ret < 0) {
1652          error_setg(errp, "dump: failed to write start flat header");
1653          return;
1654      }
1655  
1656      write_dump_header(s, errp);
1657      if (*errp) {
1658          return;
1659      }
1660  
1661      write_dump_bitmap(s, errp);
1662      if (*errp) {
1663          return;
1664      }
1665  
1666      write_dump_pages(s, errp);
1667      if (*errp) {
1668          return;
1669      }
1670  
1671      ret = write_end_flat_header(s->fd);
1672      if (ret < 0) {
1673          error_setg(errp, "dump: failed to write end flat header");
1674          return;
1675      }
1676  }
1677  
1678  static int validate_start_block(DumpState *s)
1679  {
1680      GuestPhysBlock *block;
1681  
1682      if (!dump_has_filter(s)) {
1683          return 0;
1684      }
1685  
1686      QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1687          /* This block is out of the range */
1688          if (block->target_start >= s->filter_area_begin + s->filter_area_length ||
1689              block->target_end <= s->filter_area_begin) {
1690              continue;
1691          }
1692          return 0;
1693     }
1694  
1695      return -1;
1696  }
1697  
1698  static void get_max_mapnr(DumpState *s)
1699  {
1700      GuestPhysBlock *last_block;
1701  
1702      last_block = QTAILQ_LAST(&s->guest_phys_blocks.head);
1703      s->max_mapnr = dump_paddr_to_pfn(s, last_block->target_end);
1704  }
1705  
1706  static DumpState dump_state_global = { .status = DUMP_STATUS_NONE };
1707  
1708  static void dump_state_prepare(DumpState *s)
1709  {
1710      /* zero the struct, setting status to active */
1711      *s = (DumpState) { .status = DUMP_STATUS_ACTIVE };
1712  }
1713  
1714  bool qemu_system_dump_in_progress(void)
1715  {
1716      DumpState *state = &dump_state_global;
1717      return (qatomic_read(&state->status) == DUMP_STATUS_ACTIVE);
1718  }
1719  
1720  /*
1721   * calculate total size of memory to be dumped (taking filter into
1722   * account.)
1723   */
1724  static int64_t dump_calculate_size(DumpState *s)
1725  {
1726      GuestPhysBlock *block;
1727      int64_t total = 0;
1728  
1729      QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1730          total += dump_filtered_memblock_size(block,
1731                                               s->filter_area_begin,
1732                                               s->filter_area_length);
1733      }
1734  
1735      return total;
1736  }
1737  
1738  static void vmcoreinfo_update_phys_base(DumpState *s)
1739  {
1740      uint64_t size, note_head_size, name_size, phys_base;
1741      char **lines;
1742      uint8_t *vmci;
1743      size_t i;
1744  
1745      if (!note_name_equal(s, s->guest_note, "VMCOREINFO")) {
1746          return;
1747      }
1748  
1749      get_note_sizes(s, s->guest_note, &note_head_size, &name_size, &size);
1750      note_head_size = ROUND_UP(note_head_size, 4);
1751  
1752      vmci = s->guest_note + note_head_size + ROUND_UP(name_size, 4);
1753      *(vmci + size) = '\0';
1754  
1755      lines = g_strsplit((char *)vmci, "\n", -1);
1756      for (i = 0; lines[i]; i++) {
1757          const char *prefix = NULL;
1758  
1759          if (s->dump_info.d_machine == EM_X86_64) {
1760              prefix = "NUMBER(phys_base)=";
1761          } else if (s->dump_info.d_machine == EM_AARCH64) {
1762              prefix = "NUMBER(PHYS_OFFSET)=";
1763          }
1764  
1765          if (prefix && g_str_has_prefix(lines[i], prefix)) {
1766              if (qemu_strtou64(lines[i] + strlen(prefix), NULL, 16,
1767                                &phys_base) < 0) {
1768                  warn_report("Failed to read %s", prefix);
1769              } else {
1770                  s->dump_info.phys_base = phys_base;
1771              }
1772              break;
1773          }
1774      }
1775  
1776      g_strfreev(lines);
1777  }
1778  
1779  static void dump_init(DumpState *s, int fd, bool has_format,
1780                        DumpGuestMemoryFormat format, bool paging, bool has_filter,
1781                        int64_t begin, int64_t length, Error **errp)
1782  {
1783      ERRP_GUARD();
1784      VMCoreInfoState *vmci = vmcoreinfo_find();
1785      CPUState *cpu;
1786      int nr_cpus;
1787      int ret;
1788  
1789      s->has_format = has_format;
1790      s->format = format;
1791      s->written_size = 0;
1792  
1793      /* kdump-compressed is conflict with paging and filter */
1794      if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1795          assert(!paging && !has_filter);
1796      }
1797  
1798      if (runstate_is_running()) {
1799          vm_stop(RUN_STATE_SAVE_VM);
1800          s->resume = true;
1801      } else {
1802          s->resume = false;
1803      }
1804  
1805      /* If we use KVM, we should synchronize the registers before we get dump
1806       * info or physmap info.
1807       */
1808      cpu_synchronize_all_states();
1809      nr_cpus = 0;
1810      CPU_FOREACH(cpu) {
1811          nr_cpus++;
1812      }
1813  
1814      s->fd = fd;
1815      if (has_filter && !length) {
1816          error_setg(errp, QERR_INVALID_PARAMETER, "length");
1817          goto cleanup;
1818      }
1819      s->filter_area_begin = begin;
1820      s->filter_area_length = length;
1821  
1822      /* First index is 0, it's the special null name */
1823      s->string_table_buf = g_array_new(FALSE, TRUE, 1);
1824      /*
1825       * Allocate the null name, due to the clearing option set to true
1826       * it will be 0.
1827       */
1828      g_array_set_size(s->string_table_buf, 1);
1829  
1830      memory_mapping_list_init(&s->list);
1831  
1832      guest_phys_blocks_init(&s->guest_phys_blocks);
1833      guest_phys_blocks_append(&s->guest_phys_blocks);
1834      s->total_size = dump_calculate_size(s);
1835  #ifdef DEBUG_DUMP_GUEST_MEMORY
1836      fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
1837  #endif
1838  
1839      /* it does not make sense to dump non-existent memory */
1840      if (!s->total_size) {
1841          error_setg(errp, "dump: no guest memory to dump");
1842          goto cleanup;
1843      }
1844  
1845      /* Is the filter filtering everything? */
1846      if (validate_start_block(s) == -1) {
1847          error_setg(errp, QERR_INVALID_PARAMETER, "begin");
1848          goto cleanup;
1849      }
1850  
1851      /* get dump info: endian, class and architecture.
1852       * If the target architecture is not supported, cpu_get_dump_info() will
1853       * return -1.
1854       */
1855      ret = cpu_get_dump_info(&s->dump_info, &s->guest_phys_blocks);
1856      if (ret < 0) {
1857          error_setg(errp,
1858                     "dumping guest memory is not supported on this target");
1859          goto cleanup;
1860      }
1861  
1862      if (!s->dump_info.page_size) {
1863          s->dump_info.page_size = TARGET_PAGE_SIZE;
1864      }
1865  
1866      s->note_size = cpu_get_note_size(s->dump_info.d_class,
1867                                       s->dump_info.d_machine, nr_cpus);
1868      assert(s->note_size >= 0);
1869  
1870      /*
1871       * The goal of this block is to (a) update the previously guessed
1872       * phys_base, (b) copy the guest note out of the guest.
1873       * Failure to do so is not fatal for dumping.
1874       */
1875      if (vmci) {
1876          uint64_t addr, note_head_size, name_size, desc_size;
1877          uint32_t size;
1878          uint16_t format;
1879  
1880          note_head_size = dump_is_64bit(s) ?
1881              sizeof(Elf64_Nhdr) : sizeof(Elf32_Nhdr);
1882  
1883          format = le16_to_cpu(vmci->vmcoreinfo.guest_format);
1884          size = le32_to_cpu(vmci->vmcoreinfo.size);
1885          addr = le64_to_cpu(vmci->vmcoreinfo.paddr);
1886          if (!vmci->has_vmcoreinfo) {
1887              warn_report("guest note is not present");
1888          } else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) {
1889              warn_report("guest note size is invalid: %" PRIu32, size);
1890          } else if (format != FW_CFG_VMCOREINFO_FORMAT_ELF) {
1891              warn_report("guest note format is unsupported: %" PRIu16, format);
1892          } else {
1893              s->guest_note = g_malloc(size + 1); /* +1 for adding \0 */
1894              cpu_physical_memory_read(addr, s->guest_note, size);
1895  
1896              get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_size);
1897              s->guest_note_size = ELF_NOTE_SIZE(note_head_size, name_size,
1898                                                 desc_size);
1899              if (name_size > MAX_GUEST_NOTE_SIZE ||
1900                  desc_size > MAX_GUEST_NOTE_SIZE ||
1901                  s->guest_note_size > size) {
1902                  warn_report("Invalid guest note header");
1903                  g_free(s->guest_note);
1904                  s->guest_note = NULL;
1905              } else {
1906                  vmcoreinfo_update_phys_base(s);
1907                  s->note_size += s->guest_note_size;
1908              }
1909          }
1910      }
1911  
1912      /* get memory mapping */
1913      if (paging) {
1914          qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, errp);
1915          if (*errp) {
1916              goto cleanup;
1917          }
1918      } else {
1919          qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
1920      }
1921  
1922      s->nr_cpus = nr_cpus;
1923  
1924      get_max_mapnr(s);
1925  
1926      uint64_t tmp;
1927      tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT),
1928                         s->dump_info.page_size);
1929      s->len_dump_bitmap = tmp * s->dump_info.page_size;
1930  
1931      /* init for kdump-compressed format */
1932      if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1933          switch (format) {
1934          case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
1935              s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
1936              break;
1937  
1938          case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
1939  #ifdef CONFIG_LZO
1940              if (lzo_init() != LZO_E_OK) {
1941                  error_setg(errp, "failed to initialize the LZO library");
1942                  goto cleanup;
1943              }
1944  #endif
1945              s->flag_compress = DUMP_DH_COMPRESSED_LZO;
1946              break;
1947  
1948          case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
1949              s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
1950              break;
1951  
1952          default:
1953              s->flag_compress = 0;
1954          }
1955  
1956          return;
1957      }
1958  
1959      if (dump_has_filter(s)) {
1960          memory_mapping_filter(&s->list, s->filter_area_begin, s->filter_area_length);
1961      }
1962  
1963      /*
1964       * The first section header is always a special one in which most
1965       * fields are 0. The section header string table is also always
1966       * set.
1967       */
1968      s->shdr_num = 2;
1969  
1970      /*
1971       * Adds the number of architecture sections to shdr_num and sets
1972       * elf_section_data_size so we know the offsets and sizes of all
1973       * parts.
1974       */
1975      if (s->dump_info.arch_sections_add_fn) {
1976          s->dump_info.arch_sections_add_fn(s);
1977      }
1978  
1979      /*
1980       * calculate shdr_num so we know the offsets and sizes of all
1981       * parts.
1982       * Calculate phdr_num
1983       *
1984       * The absolute maximum amount of phdrs is UINT32_MAX - 1 as
1985       * sh_info is 32 bit. There's special handling once we go over
1986       * UINT16_MAX - 1 but that is handled in the ehdr and section
1987       * code.
1988       */
1989      s->phdr_num = 1; /* Reserve PT_NOTE */
1990      if (s->list.num <= UINT32_MAX - 1) {
1991          s->phdr_num += s->list.num;
1992      } else {
1993          s->phdr_num = UINT32_MAX;
1994      }
1995  
1996      /*
1997       * Now that the number of section and program headers is known we
1998       * can calculate the offsets of the headers and data.
1999       */
2000      if (dump_is_64bit(s)) {
2001          s->shdr_offset = sizeof(Elf64_Ehdr);
2002          s->phdr_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
2003          s->note_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
2004      } else {
2005          s->shdr_offset = sizeof(Elf32_Ehdr);
2006          s->phdr_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
2007          s->note_offset = s->phdr_offset + sizeof(Elf32_Phdr) * s->phdr_num;
2008      }
2009      s->memory_offset = s->note_offset + s->note_size;
2010      s->section_offset = s->memory_offset + s->total_size;
2011  
2012      return;
2013  
2014  cleanup:
2015      dump_cleanup(s);
2016  }
2017  
2018  /* this operation might be time consuming. */
2019  static void dump_process(DumpState *s, Error **errp)
2020  {
2021      ERRP_GUARD();
2022      DumpQueryResult *result = NULL;
2023  
2024      if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
2025  #ifdef TARGET_X86_64
2026          create_win_dump(s, errp);
2027  #endif
2028      } else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
2029          create_kdump_vmcore(s, errp);
2030      } else {
2031          create_vmcore(s, errp);
2032      }
2033  
2034      /* make sure status is written after written_size updates */
2035      smp_wmb();
2036      qatomic_set(&s->status,
2037                 (*errp ? DUMP_STATUS_FAILED : DUMP_STATUS_COMPLETED));
2038  
2039      /* send DUMP_COMPLETED message (unconditionally) */
2040      result = qmp_query_dump(NULL);
2041      /* should never fail */
2042      assert(result);
2043      qapi_event_send_dump_completed(result,
2044                                     *errp ? error_get_pretty(*errp) : NULL);
2045      qapi_free_DumpQueryResult(result);
2046  
2047      dump_cleanup(s);
2048  }
2049  
2050  static void *dump_thread(void *data)
2051  {
2052      DumpState *s = (DumpState *)data;
2053      dump_process(s, NULL);
2054      return NULL;
2055  }
2056  
2057  DumpQueryResult *qmp_query_dump(Error **errp)
2058  {
2059      DumpQueryResult *result = g_new(DumpQueryResult, 1);
2060      DumpState *state = &dump_state_global;
2061      result->status = qatomic_read(&state->status);
2062      /* make sure we are reading status and written_size in order */
2063      smp_rmb();
2064      result->completed = state->written_size;
2065      result->total = state->total_size;
2066      return result;
2067  }
2068  
2069  void qmp_dump_guest_memory(bool paging, const char *file,
2070                             bool has_detach, bool detach,
2071                             bool has_begin, int64_t begin, bool has_length,
2072                             int64_t length, bool has_format,
2073                             DumpGuestMemoryFormat format, Error **errp)
2074  {
2075      ERRP_GUARD();
2076      const char *p;
2077      int fd = -1;
2078      DumpState *s;
2079      bool detach_p = false;
2080  
2081      if (runstate_check(RUN_STATE_INMIGRATE)) {
2082          error_setg(errp, "Dump not allowed during incoming migration.");
2083          return;
2084      }
2085  
2086      /* if there is a dump in background, we should wait until the dump
2087       * finished */
2088      if (qemu_system_dump_in_progress()) {
2089          error_setg(errp, "There is a dump in process, please wait.");
2090          return;
2091      }
2092  
2093      /*
2094       * kdump-compressed format need the whole memory dumped, so paging or
2095       * filter is not supported here.
2096       */
2097      if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
2098          (paging || has_begin || has_length)) {
2099          error_setg(errp, "kdump-compressed format doesn't support paging or "
2100                           "filter");
2101          return;
2102      }
2103      if (has_begin && !has_length) {
2104          error_setg(errp, QERR_MISSING_PARAMETER, "length");
2105          return;
2106      }
2107      if (!has_begin && has_length) {
2108          error_setg(errp, QERR_MISSING_PARAMETER, "begin");
2109          return;
2110      }
2111      if (has_detach) {
2112          detach_p = detach;
2113      }
2114  
2115      /* check whether lzo/snappy is supported */
2116  #ifndef CONFIG_LZO
2117      if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
2118          error_setg(errp, "kdump-lzo is not available now");
2119          return;
2120      }
2121  #endif
2122  
2123  #ifndef CONFIG_SNAPPY
2124      if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
2125          error_setg(errp, "kdump-snappy is not available now");
2126          return;
2127      }
2128  #endif
2129  
2130  #ifndef TARGET_X86_64
2131      if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
2132          error_setg(errp, "Windows dump is only available for x86-64");
2133          return;
2134      }
2135  #endif
2136  
2137  #if !defined(WIN32)
2138      if (strstart(file, "fd:", &p)) {
2139          fd = monitor_get_fd(monitor_cur(), p, errp);
2140          if (fd == -1) {
2141              return;
2142          }
2143      }
2144  #endif
2145  
2146      if  (strstart(file, "file:", &p)) {
2147          fd = qemu_open_old(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
2148          if (fd < 0) {
2149              error_setg_file_open(errp, errno, p);
2150              return;
2151          }
2152      }
2153  
2154      if (fd == -1) {
2155          error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
2156          return;
2157      }
2158  
2159      if (!dump_migration_blocker) {
2160          error_setg(&dump_migration_blocker,
2161                     "Live migration disabled: dump-guest-memory in progress");
2162      }
2163  
2164      /*
2165       * Allows even for -only-migratable, but forbid migration during the
2166       * process of dump guest memory.
2167       */
2168      if (migrate_add_blocker_internal(dump_migration_blocker, errp)) {
2169          /* Remember to release the fd before passing it over to dump state */
2170          close(fd);
2171          return;
2172      }
2173  
2174      s = &dump_state_global;
2175      dump_state_prepare(s);
2176  
2177      dump_init(s, fd, has_format, format, paging, has_begin,
2178                begin, length, errp);
2179      if (*errp) {
2180          qatomic_set(&s->status, DUMP_STATUS_FAILED);
2181          return;
2182      }
2183  
2184      if (detach_p) {
2185          /* detached dump */
2186          s->detached = true;
2187          qemu_thread_create(&s->dump_thread, "dump_thread", dump_thread,
2188                             s, QEMU_THREAD_DETACHED);
2189      } else {
2190          /* sync dump */
2191          dump_process(s, errp);
2192      }
2193  }
2194  
2195  DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
2196  {
2197      DumpGuestMemoryCapability *cap =
2198                                    g_new0(DumpGuestMemoryCapability, 1);
2199      DumpGuestMemoryFormatList **tail = &cap->formats;
2200  
2201      /* elf is always available */
2202      QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_ELF);
2203  
2204      /* kdump-zlib is always available */
2205      QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB);
2206  
2207      /* add new item if kdump-lzo is available */
2208  #ifdef CONFIG_LZO
2209      QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO);
2210  #endif
2211  
2212      /* add new item if kdump-snappy is available */
2213  #ifdef CONFIG_SNAPPY
2214      QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
2215  #endif
2216  
2217      /* Windows dump is available only if target is x86_64 */
2218  #ifdef TARGET_X86_64
2219      QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
2220  #endif
2221  
2222      return cap;
2223  }
2224