dump.c

   1 /*
   2  * QEMU dump
   3  *
   4  * Copyright Fujitsu, Corp. 2011, 2012
   5  *
   6  * Authors:
   7  *     Wen Congyang <[email protected]>
   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 "sysemu/cpus.h"
  25 #include "qapi/error.h"
  26 #include "qmp-commands.h"
  27
  28 static uint16_t cpu_convert_to_target16(uint16_t val, int endian)
  29 {
  30     if (endian == ELFDATA2LSB) {
  31         val = cpu_to_le16(val);
  32     } else {
  33         val = cpu_to_be16(val);
  34     }
  35
  36     return val;
  37 }
  38
  39 static uint32_t cpu_convert_to_target32(uint32_t val, int endian)
  40 {
  41     if (endian == ELFDATA2LSB) {
  42         val = cpu_to_le32(val);
  43     } else {
  44         val = cpu_to_be32(val);
  45     }
  46
  47     return val;
  48 }
  49
  50 static uint64_t cpu_convert_to_target64(uint64_t val, int endian)
  51 {
  52     if (endian == ELFDATA2LSB) {
  53         val = cpu_to_le64(val);
  54     } else {
  55         val = cpu_to_be64(val);
  56     }
  57
  58     return val;
  59 }
  60
  61 typedef struct DumpState {
  62     ArchDumpInfo dump_info;
  63     MemoryMappingList list;
  64     uint16_t phdr_num;
  65     uint32_t sh_info;
  66     bool have_section;
  67     bool resume;
  68     size_t note_size;
  69     hwaddr memory_offset;
  70     int fd;
  71
  72     RAMBlock *block;
  73     ram_addr_t start;
  74     bool has_filter;
  75     int64_t begin;
  76     int64_t length;
  77     Error **errp;
  78 } DumpState;
  79
  80 static int dump_cleanup(DumpState *s)
  81 {
  82     int ret = 0;
  83
  84     memory_mapping_list_free(&s->list);
  85     if (s->fd != -1) {
  86         close(s->fd);
  87     }
  88     if (s->resume) {
  89         vm_start();
  90     }
  91
  92     return ret;
  93 }
  94
  95 static void dump_error(DumpState *s, const char *reason)
  96 {
  97     dump_cleanup(s);
  98 }
  99
 100 static int fd_write_vmcore(void *buf, size_t size, void *opaque)
 101 {
 102     DumpState *s = opaque;
 103     size_t written_size;
 104
 105     written_size = qemu_write_full(s->fd, buf, size);
 106     if (written_size != size) {
 107         return -1;
 108     }
 109
 110     return 0;
 111 }
 112
 113 static int write_elf64_header(DumpState *s)
 114 {
 115     Elf64_Ehdr elf_header;
 116     int ret;
 117     int endian = s->dump_info.d_endian;
 118
 119     memset(&elf_header, 0, sizeof(Elf64_Ehdr));
 120     memcpy(&elf_header, ELFMAG, SELFMAG);
 121     elf_header.e_ident[EI_CLASS] = ELFCLASS64;
 122     elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
 123     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
 124     elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
 125     elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
 126                                                    endian);
 127     elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
 128     elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
 129     elf_header.e_phoff = cpu_convert_to_target64(sizeof(Elf64_Ehdr), endian);
 130     elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf64_Phdr),
 131                                                      endian);
 132     elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
 133     if (s->have_section) {
 134         uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;
 135
 136         elf_header.e_shoff = cpu_convert_to_target64(shoff, endian);
 137         elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf64_Shdr),
 138                                                          endian);
 139         elf_header.e_shnum = cpu_convert_to_target16(1, endian);
 140     }
 141
 142     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
 143     if (ret < 0) {
 144         dump_error(s, "dump: failed to write elf header.\n");
 145         return -1;
 146     }
 147
 148     return 0;
 149 }
 150
 151 static int write_elf32_header(DumpState *s)
 152 {
 153     Elf32_Ehdr elf_header;
 154     int ret;
 155     int endian = s->dump_info.d_endian;
 156
 157     memset(&elf_header, 0, sizeof(Elf32_Ehdr));
 158     memcpy(&elf_header, ELFMAG, SELFMAG);
 159     elf_header.e_ident[EI_CLASS] = ELFCLASS32;
 160     elf_header.e_ident[EI_DATA] = endian;
 161     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
 162     elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
 163     elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
 164                                                    endian);
 165     elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
 166     elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
 167     elf_header.e_phoff = cpu_convert_to_target32(sizeof(Elf32_Ehdr), endian);
 168     elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf32_Phdr),
 169                                                      endian);
 170     elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
 171     if (s->have_section) {
 172         uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;
 173
 174         elf_header.e_shoff = cpu_convert_to_target32(shoff, endian);
 175         elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf32_Shdr),
 176                                                          endian);
 177         elf_header.e_shnum = cpu_convert_to_target16(1, endian);
 178     }
 179
 180     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
 181     if (ret < 0) {
 182         dump_error(s, "dump: failed to write elf header.\n");
 183         return -1;
 184     }
 185
 186     return 0;
 187 }
 188
 189 static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 190                             int phdr_index, hwaddr offset)
 191 {
 192     Elf64_Phdr phdr;
 193     int ret;
 194     int endian = s->dump_info.d_endian;
 195
 196     memset(&phdr, 0, sizeof(Elf64_Phdr));
 197     phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
 198     phdr.p_offset = cpu_convert_to_target64(offset, endian);
 199     phdr.p_paddr = cpu_convert_to_target64(memory_mapping->phys_addr, endian);
 200     if (offset == -1) {
 201         /* When the memory is not stored into vmcore, offset will be -1 */
 202         phdr.p_filesz = 0;
 203     } else {
 204         phdr.p_filesz = cpu_convert_to_target64(memory_mapping->length, endian);
 205     }
 206     phdr.p_memsz = cpu_convert_to_target64(memory_mapping->length, endian);
 207     phdr.p_vaddr = cpu_convert_to_target64(memory_mapping->virt_addr, endian);
 208
 209     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
 210     if (ret < 0) {
 211         dump_error(s, "dump: failed to write program header table.\n");
 212         return -1;
 213     }
 214
 215     return 0;
 216 }
 217
 218 static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
 219                             int phdr_index, hwaddr offset)
 220 {
 221     Elf32_Phdr phdr;
 222     int ret;
 223     int endian = s->dump_info.d_endian;
 224
 225     memset(&phdr, 0, sizeof(Elf32_Phdr));
 226     phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
 227     phdr.p_offset = cpu_convert_to_target32(offset, endian);
 228     phdr.p_paddr = cpu_convert_to_target32(memory_mapping->phys_addr, endian);
 229     if (offset == -1) {
 230         /* When the memory is not stored into vmcore, offset will be -1 */
 231         phdr.p_filesz = 0;
 232     } else {
 233         phdr.p_filesz = cpu_convert_to_target32(memory_mapping->length, endian);
 234     }
 235     phdr.p_memsz = cpu_convert_to_target32(memory_mapping->length, endian);
 236     phdr.p_vaddr = cpu_convert_to_target32(memory_mapping->virt_addr, endian);
 237
 238     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 239     if (ret < 0) {
 240         dump_error(s, "dump: failed to write program header table.\n");
 241         return -1;
 242     }
 243
 244     return 0;
 245 }
 246
 247 static int write_elf64_note(DumpState *s)
 248 {
 249     Elf64_Phdr phdr;
 250     int endian = s->dump_info.d_endian;
 251     hwaddr begin = s->memory_offset - s->note_size;
 252     int ret;
 253
 254     memset(&phdr, 0, sizeof(Elf64_Phdr));
 255     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
 256     phdr.p_offset = cpu_convert_to_target64(begin, endian);
 257     phdr.p_paddr = 0;
 258     phdr.p_filesz = cpu_convert_to_target64(s->note_size, endian);
 259     phdr.p_memsz = cpu_convert_to_target64(s->note_size, endian);
 260     phdr.p_vaddr = 0;
 261
 262     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
 263     if (ret < 0) {
 264         dump_error(s, "dump: failed to write program header table.\n");
 265         return -1;
 266     }
 267
 268     return 0;
 269 }
 270
 271 static inline int cpu_index(CPUState *cpu)
 272 {
 273     return cpu->cpu_index + 1;
 274 }
 275
 276 static int write_elf64_notes(DumpState *s)
 277 {
 278     CPUArchState *env;
 279     CPUState *cpu;
 280     int ret;
 281     int id;
 282
 283     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 284         cpu = ENV_GET_CPU(env);
 285         id = cpu_index(cpu);
 286         ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
 287         if (ret < 0) {
 288             dump_error(s, "dump: failed to write elf notes.\n");
 289             return -1;
 290         }
 291     }
 292
 293     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 294         ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
 295         if (ret < 0) {
 296             dump_error(s, "dump: failed to write CPU status.\n");
 297             return -1;
 298         }
 299     }
 300
 301     return 0;
 302 }
 303
 304 static int write_elf32_note(DumpState *s)
 305 {
 306     hwaddr begin = s->memory_offset - s->note_size;
 307     Elf32_Phdr phdr;
 308     int endian = s->dump_info.d_endian;
 309     int ret;
 310
 311     memset(&phdr, 0, sizeof(Elf32_Phdr));
 312     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
 313     phdr.p_offset = cpu_convert_to_target32(begin, endian);
 314     phdr.p_paddr = 0;
 315     phdr.p_filesz = cpu_convert_to_target32(s->note_size, endian);
 316     phdr.p_memsz = cpu_convert_to_target32(s->note_size, endian);
 317     phdr.p_vaddr = 0;
 318
 319     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 320     if (ret < 0) {
 321         dump_error(s, "dump: failed to write program header table.\n");
 322         return -1;
 323     }
 324
 325     return 0;
 326 }
 327
 328 static int write_elf32_notes(DumpState *s)
 329 {
 330     CPUArchState *env;
 331     CPUState *cpu;
 332     int ret;
 333     int id;
 334
 335     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 336         cpu = ENV_GET_CPU(env);
 337         id = cpu_index(cpu);
 338         ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
 339         if (ret < 0) {
 340             dump_error(s, "dump: failed to write elf notes.\n");
 341             return -1;
 342         }
 343     }
 344
 345     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 346         ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
 347         if (ret < 0) {
 348             dump_error(s, "dump: failed to write CPU status.\n");
 349             return -1;
 350         }
 351     }
 352
 353     return 0;
 354 }
 355
 356 static int write_elf_section(DumpState *s, int type)
 357 {
 358     Elf32_Shdr shdr32;
 359     Elf64_Shdr shdr64;
 360     int endian = s->dump_info.d_endian;
 361     int shdr_size;
 362     void *shdr;
 363     int ret;
 364
 365     if (type == 0) {
 366         shdr_size = sizeof(Elf32_Shdr);
 367         memset(&shdr32, 0, shdr_size);
 368         shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
 369         shdr = &shdr32;
 370     } else {
 371         shdr_size = sizeof(Elf64_Shdr);
 372         memset(&shdr64, 0, shdr_size);
 373         shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
 374         shdr = &shdr64;
 375     }
 376
 377     ret = fd_write_vmcore(&shdr, shdr_size, s);
 378     if (ret < 0) {
 379         dump_error(s, "dump: failed to write section header table.\n");
 380         return -1;
 381     }
 382
 383     return 0;
 384 }
 385
 386 static int write_data(DumpState *s, void *buf, int length)
 387 {
 388     int ret;
 389
 390     ret = fd_write_vmcore(buf, length, s);
 391     if (ret < 0) {
 392         dump_error(s, "dump: failed to save memory.\n");
 393         return -1;
 394     }
 395
 396     return 0;
 397 }
 398
 399 /* write the memroy to vmcore. 1 page per I/O. */
 400 static int write_memory(DumpState *s, RAMBlock *block, ram_addr_t start,
 401                         int64_t size)
 402 {
 403     int64_t i;
 404     int ret;
 405
 406     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
 407         ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
 408                          TARGET_PAGE_SIZE);
 409         if (ret < 0) {
 410             return ret;
 411         }
 412     }
 413
 414     if ((size % TARGET_PAGE_SIZE) != 0) {
 415         ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
 416                          size % TARGET_PAGE_SIZE);
 417         if (ret < 0) {
 418             return ret;
 419         }
 420     }
 421
 422     return 0;
 423 }
 424
 425 /* get the memory's offset in the vmcore */
 426 static hwaddr get_offset(hwaddr phys_addr,
 427                                      DumpState *s)
 428 {
 429     RAMBlock *block;
 430     hwaddr offset = s->memory_offset;
 431     int64_t size_in_block, start;
 432
 433     if (s->has_filter) {
 434         if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
 435             return -1;
 436         }
 437     }
 438
 439     QTAILQ_FOREACH(block, &ram_list.blocks, next) {
 440         if (s->has_filter) {
 441             if (block->offset >= s->begin + s->length ||
 442                 block->offset + block->length <= s->begin) {
 443                 /* This block is out of the range */
 444                 continue;
 445             }
 446
 447             if (s->begin <= block->offset) {
 448                 start = block->offset;
 449             } else {
 450                 start = s->begin;
 451             }
 452
 453             size_in_block = block->length - (start - block->offset);
 454             if (s->begin + s->length < block->offset + block->length) {
 455                 size_in_block -= block->offset + block->length -
 456                                  (s->begin + s->length);
 457             }
 458         } else {
 459             start = block->offset;
 460             size_in_block = block->length;
 461         }
 462
 463         if (phys_addr >= start && phys_addr < start + size_in_block) {
 464             return phys_addr - start + offset;
 465         }
 466
 467         offset += size_in_block;
 468     }
 469
 470     return -1;
 471 }
 472
 473 static int write_elf_loads(DumpState *s)
 474 {
 475     hwaddr offset;
 476     MemoryMapping *memory_mapping;
 477     uint32_t phdr_index = 1;
 478     int ret;
 479     uint32_t max_index;
 480
 481     if (s->have_section) {
 482         max_index = s->sh_info;
 483     } else {
 484         max_index = s->phdr_num;
 485     }
 486
 487     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
 488         offset = get_offset(memory_mapping->phys_addr, s);
 489         if (s->dump_info.d_class == ELFCLASS64) {
 490             ret = write_elf64_load(s, memory_mapping, phdr_index++, offset);
 491         } else {
 492             ret = write_elf32_load(s, memory_mapping, phdr_index++, offset);
 493         }
 494
 495         if (ret < 0) {
 496             return -1;
 497         }
 498
 499         if (phdr_index >= max_index) {
 500             break;
 501         }
 502     }
 503
 504     return 0;
 505 }
 506
 507 /* write elf header, PT_NOTE and elf note to vmcore. */
 508 static int dump_begin(DumpState *s)
 509 {
 510     int ret;
 511
 512     /*
 513      * the vmcore's format is:
 514      *   --------------
 515      *   |  elf header |
 516      *   --------------
 517      *   |  PT_NOTE    |
 518      *   --------------
 519      *   |  PT_LOAD    |
 520      *   --------------
 521      *   |  ......     |
 522      *   --------------
 523      *   |  PT_LOAD    |
 524      *   --------------
 525      *   |  sec_hdr    |
 526      *   --------------
 527      *   |  elf note   |
 528      *   --------------
 529      *   |  memory     |
 530      *   --------------
 531      *
 532      * we only know where the memory is saved after we write elf note into
 533      * vmcore.
 534      */
 535
 536     /* write elf header to vmcore */
 537     if (s->dump_info.d_class == ELFCLASS64) {
 538         ret = write_elf64_header(s);
 539     } else {
 540         ret = write_elf32_header(s);
 541     }
 542     if (ret < 0) {
 543         return -1;
 544     }
 545
 546     if (s->dump_info.d_class == ELFCLASS64) {
 547         /* write PT_NOTE to vmcore */
 548         if (write_elf64_note(s) < 0) {
 549             return -1;
 550         }
 551
 552         /* write all PT_LOAD to vmcore */
 553         if (write_elf_loads(s) < 0) {
 554             return -1;
 555         }
 556
 557         /* write section to vmcore */
 558         if (s->have_section) {
 559             if (write_elf_section(s, 1) < 0) {
 560                 return -1;
 561             }
 562         }
 563
 564         /* write notes to vmcore */
 565         if (write_elf64_notes(s) < 0) {
 566             return -1;
 567         }
 568
 569     } else {
 570         /* write PT_NOTE to vmcore */
 571         if (write_elf32_note(s) < 0) {
 572             return -1;
 573         }
 574
 575         /* write all PT_LOAD to vmcore */
 576         if (write_elf_loads(s) < 0) {
 577             return -1;
 578         }
 579
 580         /* write section to vmcore */
 581         if (s->have_section) {
 582             if (write_elf_section(s, 0) < 0) {
 583                 return -1;
 584             }
 585         }
 586
 587         /* write notes to vmcore */
 588         if (write_elf32_notes(s) < 0) {
 589             return -1;
 590         }
 591     }
 592
 593     return 0;
 594 }
 595
 596 /* write PT_LOAD to vmcore */
 597 static int dump_completed(DumpState *s)
 598 {
 599     dump_cleanup(s);
 600     return 0;
 601 }
 602
 603 static int get_next_block(DumpState *s, RAMBlock *block)
 604 {
 605     while (1) {
 606         block = QTAILQ_NEXT(block, next);
 607         if (!block) {
 608             /* no more block */
 609             return 1;
 610         }
 611
 612         s->start = 0;
 613         s->block = block;
 614         if (s->has_filter) {
 615             if (block->offset >= s->begin + s->length ||
 616                 block->offset + block->length <= s->begin) {
 617                 /* This block is out of the range */
 618                 continue;
 619             }
 620
 621             if (s->begin > block->offset) {
 622                 s->start = s->begin - block->offset;
 623             }
 624         }
 625
 626         return 0;
 627     }
 628 }
 629
 630 /* write all memory to vmcore */
 631 static int dump_iterate(DumpState *s)
 632 {
 633     RAMBlock *block;
 634     int64_t size;
 635     int ret;
 636
 637     while (1) {
 638         block = s->block;
 639
 640         size = block->length;
 641         if (s->has_filter) {
 642             size -= s->start;
 643             if (s->begin + s->length < block->offset + block->length) {
 644                 size -= block->offset + block->length - (s->begin + s->length);
 645             }
 646         }
 647         ret = write_memory(s, block, s->start, size);
 648         if (ret == -1) {
 649             return ret;
 650         }
 651
 652         ret = get_next_block(s, block);
 653         if (ret == 1) {
 654             dump_completed(s);
 655             return 0;
 656         }
 657     }
 658 }
 659
 660 static int create_vmcore(DumpState *s)
 661 {
 662     int ret;
 663
 664     ret = dump_begin(s);
 665     if (ret < 0) {
 666         return -1;
 667     }
 668
 669     ret = dump_iterate(s);
 670     if (ret < 0) {
 671         return -1;
 672     }
 673
 674     return 0;
 675 }
 676
 677 static ram_addr_t get_start_block(DumpState *s)
 678 {
 679     RAMBlock *block;
 680
 681     if (!s->has_filter) {
 682         s->block = QTAILQ_FIRST(&ram_list.blocks);
 683         return 0;
 684     }
 685
 686     QTAILQ_FOREACH(block, &ram_list.blocks, next) {
 687         if (block->offset >= s->begin + s->length ||
 688             block->offset + block->length <= s->begin) {
 689             /* This block is out of the range */
 690             continue;
 691         }
 692
 693         s->block = block;
 694         if (s->begin > block->offset) {
 695             s->start = s->begin - block->offset;
 696         } else {
 697             s->start = 0;
 698         }
 699         return s->start;
 700     }
 701
 702     return -1;
 703 }
 704
 705 static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
 706                      int64_t begin, int64_t length, Error **errp)
 707 {
 708     CPUArchState *env;
 709     int nr_cpus;
 710     Error *err = NULL;
 711     int ret;
 712
 713     if (runstate_is_running()) {
 714         vm_stop(RUN_STATE_SAVE_VM);
 715         s->resume = true;
 716     } else {
 717         s->resume = false;
 718     }
 719
 720     s->errp = errp;
 721     s->fd = fd;
 722     s->has_filter = has_filter;
 723     s->begin = begin;
 724     s->length = length;
 725     s->start = get_start_block(s);
 726     if (s->start == -1) {
 727         error_set(errp, QERR_INVALID_PARAMETER, "begin");
 728         goto cleanup;
 729     }
 730
 731     /*
 732      * get dump info: endian, class and architecture.
 733      * If the target architecture is not supported, cpu_get_dump_info() will
 734      * return -1.
 735      *
 736      * If we use KVM, we should synchronize the registers before we get dump
 737      * info.
 738      */
 739     cpu_synchronize_all_states();
 740     nr_cpus = 0;
 741     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 742         nr_cpus++;
 743     }
 744
 745     ret = cpu_get_dump_info(&s->dump_info);
 746     if (ret < 0) {
 747         error_set(errp, QERR_UNSUPPORTED);
 748         goto cleanup;
 749     }
 750
 751     s->note_size = cpu_get_note_size(s->dump_info.d_class,
 752                                      s->dump_info.d_machine, nr_cpus);
 753     if (ret < 0) {
 754         error_set(errp, QERR_UNSUPPORTED);
 755         goto cleanup;
 756     }
 757
 758     /* get memory mapping */
 759     memory_mapping_list_init(&s->list);
 760     if (paging) {
 761         qemu_get_guest_memory_mapping(&s->list, &err);
 762         if (err != NULL) {
 763             error_propagate(errp, err);
 764             goto cleanup;
 765         }
 766     } else {
 767         qemu_get_guest_simple_memory_mapping(&s->list);
 768     }
 769
 770     if (s->has_filter) {
 771         memory_mapping_filter(&s->list, s->begin, s->length);
 772     }
 773
 774     /*
 775      * calculate phdr_num
 776      *
 777      * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
 778      */
 779     s->phdr_num = 1; /* PT_NOTE */
 780     if (s->list.num < UINT16_MAX - 2) {
 781         s->phdr_num += s->list.num;
 782         s->have_section = false;
 783     } else {
 784         s->have_section = true;
 785         s->phdr_num = PN_XNUM;
 786         s->sh_info = 1; /* PT_NOTE */
 787
 788         /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
 789         if (s->list.num <= UINT32_MAX - 1) {
 790             s->sh_info += s->list.num;
 791         } else {
 792             s->sh_info = UINT32_MAX;
 793         }
 794     }
 795
 796     if (s->dump_info.d_class == ELFCLASS64) {
 797         if (s->have_section) {
 798             s->memory_offset = sizeof(Elf64_Ehdr) +
 799                                sizeof(Elf64_Phdr) * s->sh_info +
 800                                sizeof(Elf64_Shdr) + s->note_size;
 801         } else {
 802             s->memory_offset = sizeof(Elf64_Ehdr) +
 803                                sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;
 804         }
 805     } else {
 806         if (s->have_section) {
 807             s->memory_offset = sizeof(Elf32_Ehdr) +
 808                                sizeof(Elf32_Phdr) * s->sh_info +
 809                                sizeof(Elf32_Shdr) + s->note_size;
 810         } else {
 811             s->memory_offset = sizeof(Elf32_Ehdr) +
 812                                sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;
 813         }
 814     }
 815
 816     return 0;
 817
 818 cleanup:
 819     if (s->resume) {
 820         vm_start();
 821     }
 822
 823     return -1;
 824 }
 825
 826 void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
 827                            int64_t begin, bool has_length, int64_t length,
 828                            Error **errp)
 829 {
 830     const char *p;
 831     int fd = -1;
 832     DumpState *s;
 833     int ret;
 834
 835     if (has_begin && !has_length) {
 836         error_set(errp, QERR_MISSING_PARAMETER, "length");
 837         return;
 838     }
 839     if (!has_begin && has_length) {
 840         error_set(errp, QERR_MISSING_PARAMETER, "begin");
 841         return;
 842     }
 843
 844 #if !defined(WIN32)
 845     if (strstart(file, "fd:", &p)) {
 846         fd = monitor_get_fd(cur_mon, p, errp);
 847         if (fd == -1) {
 848             return;
 849         }
 850     }
 851 #endif
 852
 853     if  (strstart(file, "file:", &p)) {
 854         fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
 855         if (fd < 0) {
 856             error_setg_file_open(errp, errno, p);
 857             return;
 858         }
 859     }
 860
 861     if (fd == -1) {
 862         error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 863         return;
 864     }
 865
 866     s = g_malloc(sizeof(DumpState));
 867
 868     ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
 869     if (ret < 0) {
 870         g_free(s);
 871         return;
 872     }
 873
 874     if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
 875         error_set(errp, QERR_IO_ERROR);
 876     }
 877
 878     g_free(s);
 879 }