dump.c

   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-common.h"
  15 #include "elf.h"
  16 #include "cpu.h"
  17 #include "exec/cpu-all.h"
  18 #include "exec/hwaddr.h"
  19 #include "monitor/monitor.h"
  20 #include "sysemu/kvm.h"
  21 #include "sysemu/dump.h"
  22 #include "sysemu/sysemu.h"
  23 #include "sysemu/memory_mapping.h"
  24 #include "qapi/error.h"
  25 #include "qmp-commands.h"
  26
  27 static uint16_t cpu_convert_to_target16(uint16_t val, int endian)
  28 {
  29     if (endian == ELFDATA2LSB) {
  30         val = cpu_to_le16(val);
  31     } else {
  32         val = cpu_to_be16(val);
  33     }
  34
  35     return val;
  36 }
  37
  38 static uint32_t cpu_convert_to_target32(uint32_t val, int endian)
  39 {
  40     if (endian == ELFDATA2LSB) {
  41         val = cpu_to_le32(val);
  42     } else {
  43         val = cpu_to_be32(val);
  44     }
  45
  46     return val;
  47 }
  48
  49 static uint64_t cpu_convert_to_target64(uint64_t val, int endian)
  50 {
  51     if (endian == ELFDATA2LSB) {
  52         val = cpu_to_le64(val);
  53     } else {
  54         val = cpu_to_be64(val);
  55     }
  56
  57     return val;
  58 }
  59
  60 typedef struct DumpState {
  61     ArchDumpInfo dump_info;
  62     MemoryMappingList list;
  63     uint16_t phdr_num;
  64     uint32_t sh_info;
  65     bool have_section;
  66     bool resume;
  67     size_t note_size;
  68     hwaddr memory_offset;
  69     int fd;
  70
  71     RAMBlock *block;
  72     ram_addr_t start;
  73     bool has_filter;
  74     int64_t begin;
  75     int64_t length;
  76     Error **errp;
  77 } DumpState;
  78
  79 static int dump_cleanup(DumpState *s)
  80 {
  81     int ret = 0;
  82
  83     memory_mapping_list_free(&s->list);
  84     if (s->fd != -1) {
  85         close(s->fd);
  86     }
  87     if (s->resume) {
  88         vm_start();
  89     }
  90
  91     return ret;
  92 }
  93
  94 static void dump_error(DumpState *s, const char *reason)
  95 {
  96     dump_cleanup(s);
  97 }
  98
  99 static int fd_write_vmcore(void *buf, size_t size, void *opaque)
 100 {
 101     DumpState *s = opaque;
 102     size_t written_size;
 103
 104     written_size = qemu_write_full(s->fd, buf, size);
 105     if (written_size != size) {
 106         return -1;
 107     }
 108
 109     return 0;
 110 }
 111
 112 static int write_elf64_header(DumpState *s)
 113 {
 114     Elf64_Ehdr elf_header;
 115     int ret;
 116     int endian = s->dump_info.d_endian;
 117
 118     memset(&elf_header, 0, sizeof(Elf64_Ehdr));
 119     memcpy(&elf_header, ELFMAG, SELFMAG);
 120     elf_header.e_ident[EI_CLASS] = ELFCLASS64;
 121     elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
 122     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
 123     elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
 124     elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
 125                                                    endian);
 126     elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
 127     elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
 128     elf_header.e_phoff = cpu_convert_to_target64(sizeof(Elf64_Ehdr), endian);
 129     elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf64_Phdr),
 130                                                      endian);
 131     elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
 132     if (s->have_section) {
 133         uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;
 134
 135         elf_header.e_shoff = cpu_convert_to_target64(shoff, endian);
 136         elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf64_Shdr),
 137                                                          endian);
 138         elf_header.e_shnum = cpu_convert_to_target16(1, endian);
 139     }
 140
 141     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
 142     if (ret < 0) {
 143         dump_error(s, "dump: failed to write elf header.\n");
 144         return -1;
 145     }
 146
 147     return 0;
 148 }
 149
 150 static int write_elf32_header(DumpState *s)
 151 {
 152     Elf32_Ehdr elf_header;
 153     int ret;
 154     int endian = s->dump_info.d_endian;
 155
 156     memset(&elf_header, 0, sizeof(Elf32_Ehdr));
 157     memcpy(&elf_header, ELFMAG, SELFMAG);
 158     elf_header.e_ident[EI_CLASS] = ELFCLASS32;
 159     elf_header.e_ident[EI_DATA] = endian;
 160     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
 161     elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
 162     elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
 163                                                    endian);
 164     elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
 165     elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
 166     elf_header.e_phoff = cpu_convert_to_target32(sizeof(Elf32_Ehdr), endian);
 167     elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf32_Phdr),
 168                                                      endian);
 169     elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
 170     if (s->have_section) {
 171         uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;
 172
 173         elf_header.e_shoff = cpu_convert_to_target32(shoff, endian);
 174         elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf32_Shdr),
 175                                                          endian);
 176         elf_header.e_shnum = cpu_convert_to_target16(1, endian);
 177     }
 178
 179     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
 180     if (ret < 0) {
 181         dump_error(s, "dump: failed to write elf header.\n");
 182         return -1;
 183     }
 184
 185     return 0;
 186 }
 187
 188 static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 189                             int phdr_index, hwaddr offset)
 190 {
 191     Elf64_Phdr phdr;
 192     int ret;
 193     int endian = s->dump_info.d_endian;
 194
 195     memset(&phdr, 0, sizeof(Elf64_Phdr));
 196     phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
 197     phdr.p_offset = cpu_convert_to_target64(offset, endian);
 198     phdr.p_paddr = cpu_convert_to_target64(memory_mapping->phys_addr, endian);
 199     if (offset == -1) {
 200         /* When the memory is not stored into vmcore, offset will be -1 */
 201         phdr.p_filesz = 0;
 202     } else {
 203         phdr.p_filesz = cpu_convert_to_target64(memory_mapping->length, endian);
 204     }
 205     phdr.p_memsz = cpu_convert_to_target64(memory_mapping->length, endian);
 206     phdr.p_vaddr = cpu_convert_to_target64(memory_mapping->virt_addr, endian);
 207
 208     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
 209     if (ret < 0) {
 210         dump_error(s, "dump: failed to write program header table.\n");
 211         return -1;
 212     }
 213
 214     return 0;
 215 }
 216
 217 static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
 218                             int phdr_index, hwaddr offset)
 219 {
 220     Elf32_Phdr phdr;
 221     int ret;
 222     int endian = s->dump_info.d_endian;
 223
 224     memset(&phdr, 0, sizeof(Elf32_Phdr));
 225     phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
 226     phdr.p_offset = cpu_convert_to_target32(offset, endian);
 227     phdr.p_paddr = cpu_convert_to_target32(memory_mapping->phys_addr, endian);
 228     if (offset == -1) {
 229         /* When the memory is not stored into vmcore, offset will be -1 */
 230         phdr.p_filesz = 0;
 231     } else {
 232         phdr.p_filesz = cpu_convert_to_target32(memory_mapping->length, endian);
 233     }
 234     phdr.p_memsz = cpu_convert_to_target32(memory_mapping->length, endian);
 235     phdr.p_vaddr = cpu_convert_to_target32(memory_mapping->virt_addr, endian);
 236
 237     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 238     if (ret < 0) {
 239         dump_error(s, "dump: failed to write program header table.\n");
 240         return -1;
 241     }
 242
 243     return 0;
 244 }
 245
 246 static int write_elf64_note(DumpState *s)
 247 {
 248     Elf64_Phdr phdr;
 249     int endian = s->dump_info.d_endian;
 250     hwaddr begin = s->memory_offset - s->note_size;
 251     int ret;
 252
 253     memset(&phdr, 0, sizeof(Elf64_Phdr));
 254     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
 255     phdr.p_offset = cpu_convert_to_target64(begin, endian);
 256     phdr.p_paddr = 0;
 257     phdr.p_filesz = cpu_convert_to_target64(s->note_size, endian);
 258     phdr.p_memsz = cpu_convert_to_target64(s->note_size, endian);
 259     phdr.p_vaddr = 0;
 260
 261     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
 262     if (ret < 0) {
 263         dump_error(s, "dump: failed to write program header table.\n");
 264         return -1;
 265     }
 266
 267     return 0;
 268 }
 269
 270 static inline int cpu_index(CPUState *cpu)
 271 {
 272     return cpu->cpu_index + 1;
 273 }
 274
 275 static int write_elf64_notes(DumpState *s)
 276 {
 277     CPUArchState *env;
 278     CPUState *cpu;
 279     int ret;
 280     int id;
 281
 282     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 283         cpu = ENV_GET_CPU(env);
 284         id = cpu_index(cpu);
 285         ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
 286         if (ret < 0) {
 287             dump_error(s, "dump: failed to write elf notes.\n");
 288             return -1;
 289         }
 290     }
 291
 292     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 293         ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
 294         if (ret < 0) {
 295             dump_error(s, "dump: failed to write CPU status.\n");
 296             return -1;
 297         }
 298     }
 299
 300     return 0;
 301 }
 302
 303 static int write_elf32_note(DumpState *s)
 304 {
 305     hwaddr begin = s->memory_offset - s->note_size;
 306     Elf32_Phdr phdr;
 307     int endian = s->dump_info.d_endian;
 308     int ret;
 309
 310     memset(&phdr, 0, sizeof(Elf32_Phdr));
 311     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
 312     phdr.p_offset = cpu_convert_to_target32(begin, endian);
 313     phdr.p_paddr = 0;
 314     phdr.p_filesz = cpu_convert_to_target32(s->note_size, endian);
 315     phdr.p_memsz = cpu_convert_to_target32(s->note_size, endian);
 316     phdr.p_vaddr = 0;
 317
 318     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 319     if (ret < 0) {
 320         dump_error(s, "dump: failed to write program header table.\n");
 321         return -1;
 322     }
 323
 324     return 0;
 325 }
 326
 327 static int write_elf32_notes(DumpState *s)
 328 {
 329     CPUArchState *env;
 330     CPUState *cpu;
 331     int ret;
 332     int id;
 333
 334     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 335         cpu = ENV_GET_CPU(env);
 336         id = cpu_index(cpu);
 337         ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
 338         if (ret < 0) {
 339             dump_error(s, "dump: failed to write elf notes.\n");
 340             return -1;
 341         }
 342     }
 343
 344     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 345         ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
 346         if (ret < 0) {
 347             dump_error(s, "dump: failed to write CPU status.\n");
 348             return -1;
 349         }
 350     }
 351
 352     return 0;
 353 }
 354
 355 static int write_elf_section(DumpState *s, int type)
 356 {
 357     Elf32_Shdr shdr32;
 358     Elf64_Shdr shdr64;
 359     int endian = s->dump_info.d_endian;
 360     int shdr_size;
 361     void *shdr;
 362     int ret;
 363
 364     if (type == 0) {
 365         shdr_size = sizeof(Elf32_Shdr);
 366         memset(&shdr32, 0, shdr_size);
 367         shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
 368         shdr = &shdr32;
 369     } else {
 370         shdr_size = sizeof(Elf64_Shdr);
 371         memset(&shdr64, 0, shdr_size);
 372         shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
 373         shdr = &shdr64;
 374     }
 375
 376     ret = fd_write_vmcore(&shdr, shdr_size, s);
 377     if (ret < 0) {
 378         dump_error(s, "dump: failed to write section header table.\n");
 379         return -1;
 380     }
 381
 382     return 0;
 383 }
 384
 385 static int write_data(DumpState *s, void *buf, int length)
 386 {
 387     int ret;
 388
 389     ret = fd_write_vmcore(buf, length, s);
 390     if (ret < 0) {
 391         dump_error(s, "dump: failed to save memory.\n");
 392         return -1;
 393     }
 394
 395     return 0;
 396 }
 397
 398 /* write the memroy to vmcore. 1 page per I/O. */
 399 static int write_memory(DumpState *s, RAMBlock *block, ram_addr_t start,
 400                         int64_t size)
 401 {
 402     int64_t i;
 403     int ret;
 404
 405     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
 406         ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
 407                          TARGET_PAGE_SIZE);
 408         if (ret < 0) {
 409             return ret;
 410         }
 411     }
 412
 413     if ((size % TARGET_PAGE_SIZE) != 0) {
 414         ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
 415                          size % TARGET_PAGE_SIZE);
 416         if (ret < 0) {
 417             return ret;
 418         }
 419     }
 420
 421     return 0;
 422 }
 423
 424 /* get the memory's offset in the vmcore */
 425 static hwaddr get_offset(hwaddr phys_addr,
 426                                      DumpState *s)
 427 {
 428     RAMBlock *block;
 429     hwaddr offset = s->memory_offset;
 430     int64_t size_in_block, start;
 431
 432     if (s->has_filter) {
 433         if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
 434             return -1;
 435         }
 436     }
 437
 438     QTAILQ_FOREACH(block, &ram_list.blocks, next) {
 439         if (s->has_filter) {
 440             if (block->offset >= s->begin + s->length ||
 441                 block->offset + block->length <= s->begin) {
 442                 /* This block is out of the range */
 443                 continue;
 444             }
 445
 446             if (s->begin <= block->offset) {
 447                 start = block->offset;
 448             } else {
 449                 start = s->begin;
 450             }
 451
 452             size_in_block = block->length - (start - block->offset);
 453             if (s->begin + s->length < block->offset + block->length) {
 454                 size_in_block -= block->offset + block->length -
 455                                  (s->begin + s->length);
 456             }
 457         } else {
 458             start = block->offset;
 459             size_in_block = block->length;
 460         }
 461
 462         if (phys_addr >= start && phys_addr < start + size_in_block) {
 463             return phys_addr - start + offset;
 464         }
 465
 466         offset += size_in_block;
 467     }
 468
 469     return -1;
 470 }
 471
 472 static int write_elf_loads(DumpState *s)
 473 {
 474     hwaddr offset;
 475     MemoryMapping *memory_mapping;
 476     uint32_t phdr_index = 1;
 477     int ret;
 478     uint32_t max_index;
 479
 480     if (s->have_section) {
 481         max_index = s->sh_info;
 482     } else {
 483         max_index = s->phdr_num;
 484     }
 485
 486     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
 487         offset = get_offset(memory_mapping->phys_addr, s);
 488         if (s->dump_info.d_class == ELFCLASS64) {
 489             ret = write_elf64_load(s, memory_mapping, phdr_index++, offset);
 490         } else {
 491             ret = write_elf32_load(s, memory_mapping, phdr_index++, offset);
 492         }
 493
 494         if (ret < 0) {
 495             return -1;
 496         }
 497
 498         if (phdr_index >= max_index) {
 499             break;
 500         }
 501     }
 502
 503     return 0;
 504 }
 505
 506 /* write elf header, PT_NOTE and elf note to vmcore. */
 507 static int dump_begin(DumpState *s)
 508 {
 509     int ret;
 510
 511     /*
 512      * the vmcore's format is:
 513      *   --------------
 514      *   |  elf header |
 515      *   --------------
 516      *   |  PT_NOTE    |
 517      *   --------------
 518      *   |  PT_LOAD    |
 519      *   --------------
 520      *   |  ......     |
 521      *   --------------
 522      *   |  PT_LOAD    |
 523      *   --------------
 524      *   |  sec_hdr    |
 525      *   --------------
 526      *   |  elf note   |
 527      *   --------------
 528      *   |  memory     |
 529      *   --------------
 530      *
 531      * we only know where the memory is saved after we write elf note into
 532      * vmcore.
 533      */
 534
 535     /* write elf header to vmcore */
 536     if (s->dump_info.d_class == ELFCLASS64) {
 537         ret = write_elf64_header(s);
 538     } else {
 539         ret = write_elf32_header(s);
 540     }
 541     if (ret < 0) {
 542         return -1;
 543     }
 544
 545     if (s->dump_info.d_class == ELFCLASS64) {
 546         /* write PT_NOTE to vmcore */
 547         if (write_elf64_note(s) < 0) {
 548             return -1;
 549         }
 550
 551         /* write all PT_LOAD to vmcore */
 552         if (write_elf_loads(s) < 0) {
 553             return -1;
 554         }
 555
 556         /* write section to vmcore */
 557         if (s->have_section) {
 558             if (write_elf_section(s, 1) < 0) {
 559                 return -1;
 560             }
 561         }
 562
 563         /* write notes to vmcore */
 564         if (write_elf64_notes(s) < 0) {
 565             return -1;
 566         }
 567
 568     } else {
 569         /* write PT_NOTE to vmcore */
 570         if (write_elf32_note(s) < 0) {
 571             return -1;
 572         }
 573
 574         /* write all PT_LOAD to vmcore */
 575         if (write_elf_loads(s) < 0) {
 576             return -1;
 577         }
 578
 579         /* write section to vmcore */
 580         if (s->have_section) {
 581             if (write_elf_section(s, 0) < 0) {
 582                 return -1;
 583             }
 584         }
 585
 586         /* write notes to vmcore */
 587         if (write_elf32_notes(s) < 0) {
 588             return -1;
 589         }
 590     }
 591
 592     return 0;
 593 }
 594
 595 /* write PT_LOAD to vmcore */
 596 static int dump_completed(DumpState *s)
 597 {
 598     dump_cleanup(s);
 599     return 0;
 600 }
 601
 602 static int get_next_block(DumpState *s, RAMBlock *block)
 603 {
 604     while (1) {
 605         block = QTAILQ_NEXT(block, next);
 606         if (!block) {
 607             /* no more block */
 608             return 1;
 609         }
 610
 611         s->start = 0;
 612         s->block = block;
 613         if (s->has_filter) {
 614             if (block->offset >= s->begin + s->length ||
 615                 block->offset + block->length <= s->begin) {
 616                 /* This block is out of the range */
 617                 continue;
 618             }
 619
 620             if (s->begin > block->offset) {
 621                 s->start = s->begin - block->offset;
 622             }
 623         }
 624
 625         return 0;
 626     }
 627 }
 628
 629 /* write all memory to vmcore */
 630 static int dump_iterate(DumpState *s)
 631 {
 632     RAMBlock *block;
 633     int64_t size;
 634     int ret;
 635
 636     while (1) {
 637         block = s->block;
 638
 639         size = block->length;
 640         if (s->has_filter) {
 641             size -= s->start;
 642             if (s->begin + s->length < block->offset + block->length) {
 643                 size -= block->offset + block->length - (s->begin + s->length);
 644             }
 645         }
 646         ret = write_memory(s, block, s->start, size);
 647         if (ret == -1) {
 648             return ret;
 649         }
 650
 651         ret = get_next_block(s, block);
 652         if (ret == 1) {
 653             dump_completed(s);
 654             return 0;
 655         }
 656     }
 657 }
 658
 659 static int create_vmcore(DumpState *s)
 660 {
 661     int ret;
 662
 663     ret = dump_begin(s);
 664     if (ret < 0) {
 665         return -1;
 666     }
 667
 668     ret = dump_iterate(s);
 669     if (ret < 0) {
 670         return -1;
 671     }
 672
 673     return 0;
 674 }
 675
 676 static ram_addr_t get_start_block(DumpState *s)
 677 {
 678     RAMBlock *block;
 679
 680     if (!s->has_filter) {
 681         s->block = QTAILQ_FIRST(&ram_list.blocks);
 682         return 0;
 683     }
 684
 685     QTAILQ_FOREACH(block, &ram_list.blocks, next) {
 686         if (block->offset >= s->begin + s->length ||
 687             block->offset + block->length <= s->begin) {
 688             /* This block is out of the range */
 689             continue;
 690         }
 691
 692         s->block = block;
 693         if (s->begin > block->offset) {
 694             s->start = s->begin - block->offset;
 695         } else {
 696             s->start = 0;
 697         }
 698         return s->start;
 699     }
 700
 701     return -1;
 702 }
 703
 704 static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
 705                      int64_t begin, int64_t length, Error **errp)
 706 {
 707     CPUArchState *env;
 708     int nr_cpus;
 709     int ret;
 710
 711     if (runstate_is_running()) {
 712         vm_stop(RUN_STATE_SAVE_VM);
 713         s->resume = true;
 714     } else {
 715         s->resume = false;
 716     }
 717
 718     s->errp = errp;
 719     s->fd = fd;
 720     s->has_filter = has_filter;
 721     s->begin = begin;
 722     s->length = length;
 723     s->start = get_start_block(s);
 724     if (s->start == -1) {
 725         error_set(errp, QERR_INVALID_PARAMETER, "begin");
 726         goto cleanup;
 727     }
 728
 729     /*
 730      * get dump info: endian, class and architecture.
 731      * If the target architecture is not supported, cpu_get_dump_info() will
 732      * return -1.
 733      *
 734      * if we use kvm, we should synchronize the register before we get dump
 735      * info.
 736      */
 737     nr_cpus = 0;
 738     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 739         cpu_synchronize_state(env);
 740         nr_cpus++;
 741     }
 742
 743     ret = cpu_get_dump_info(&s->dump_info);
 744     if (ret < 0) {
 745         error_set(errp, QERR_UNSUPPORTED);
 746         goto cleanup;
 747     }
 748
 749     s->note_size = cpu_get_note_size(s->dump_info.d_class,
 750                                      s->dump_info.d_machine, nr_cpus);
 751     if (ret < 0) {
 752         error_set(errp, QERR_UNSUPPORTED);
 753         goto cleanup;
 754     }
 755
 756     /* get memory mapping */
 757     memory_mapping_list_init(&s->list);
 758     if (paging) {
 759         qemu_get_guest_memory_mapping(&s->list);
 760     } else {
 761         qemu_get_guest_simple_memory_mapping(&s->list);
 762     }
 763
 764     if (s->has_filter) {
 765         memory_mapping_filter(&s->list, s->begin, s->length);
 766     }
 767
 768     /*
 769      * calculate phdr_num
 770      *
 771      * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
 772      */
 773     s->phdr_num = 1; /* PT_NOTE */
 774     if (s->list.num < UINT16_MAX - 2) {
 775         s->phdr_num += s->list.num;
 776         s->have_section = false;
 777     } else {
 778         s->have_section = true;
 779         s->phdr_num = PN_XNUM;
 780         s->sh_info = 1; /* PT_NOTE */
 781
 782         /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
 783         if (s->list.num <= UINT32_MAX - 1) {
 784             s->sh_info += s->list.num;
 785         } else {
 786             s->sh_info = UINT32_MAX;
 787         }
 788     }
 789
 790     if (s->dump_info.d_class == ELFCLASS64) {
 791         if (s->have_section) {
 792             s->memory_offset = sizeof(Elf64_Ehdr) +
 793                                sizeof(Elf64_Phdr) * s->sh_info +
 794                                sizeof(Elf64_Shdr) + s->note_size;
 795         } else {
 796             s->memory_offset = sizeof(Elf64_Ehdr) +
 797                                sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;
 798         }
 799     } else {
 800         if (s->have_section) {
 801             s->memory_offset = sizeof(Elf32_Ehdr) +
 802                                sizeof(Elf32_Phdr) * s->sh_info +
 803                                sizeof(Elf32_Shdr) + s->note_size;
 804         } else {
 805             s->memory_offset = sizeof(Elf32_Ehdr) +
 806                                sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;
 807         }
 808     }
 809
 810     return 0;
 811
 812 cleanup:
 813     if (s->resume) {
 814         vm_start();
 815     }
 816
 817     return -1;
 818 }
 819
 820 void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
 821                            int64_t begin, bool has_length, int64_t length,
 822                            Error **errp)
 823 {
 824     const char *p;
 825     int fd = -1;
 826     DumpState *s;
 827     int ret;
 828
 829     if (has_begin && !has_length) {
 830         error_set(errp, QERR_MISSING_PARAMETER, "length");
 831         return;
 832     }
 833     if (!has_begin && has_length) {
 834         error_set(errp, QERR_MISSING_PARAMETER, "begin");
 835         return;
 836     }
 837
 838 #if !defined(WIN32)
 839     if (strstart(file, "fd:", &p)) {
 840         fd = monitor_get_fd(cur_mon, p, errp);
 841         if (fd == -1) {
 842             return;
 843         }
 844     }
 845 #endif
 846
 847     if  (strstart(file, "file:", &p)) {
 848         fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
 849         if (fd < 0) {
 850             error_set(errp, QERR_OPEN_FILE_FAILED, p);
 851             return;
 852         }
 853     }
 854
 855     if (fd == -1) {
 856         error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 857         return;
 858     }
 859
 860     s = g_malloc(sizeof(DumpState));
 861
 862     ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
 863     if (ret < 0) {
 864         g_free(s);
 865         return;
 866     }
 867
 868     if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
 869         error_set(errp, QERR_IO_ERROR);
 870     }
 871
 872     g_free(s);
 873 }