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 "qapi/error.h"
  25 #include "qmp-commands.h"
  26 #include "exec/gdbstub.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 int write_elf64_notes(DumpState *s)
 272 {
 273     CPUArchState *env;
 274     CPUState *cpu;
 275     int ret;
 276     int id;
 277
 278     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 279         cpu = ENV_GET_CPU(env);
 280         id = cpu_index(cpu);
 281         ret = cpu_write_elf64_note(fd_write_vmcore, env, id, s);
 282         if (ret < 0) {
 283             dump_error(s, "dump: failed to write elf notes.\n");
 284             return -1;
 285         }
 286     }
 287
 288     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 289         ret = cpu_write_elf64_qemunote(fd_write_vmcore, env, s);
 290         if (ret < 0) {
 291             dump_error(s, "dump: failed to write CPU status.\n");
 292             return -1;
 293         }
 294     }
 295
 296     return 0;
 297 }
 298
 299 static int write_elf32_note(DumpState *s)
 300 {
 301     hwaddr begin = s->memory_offset - s->note_size;
 302     Elf32_Phdr phdr;
 303     int endian = s->dump_info.d_endian;
 304     int ret;
 305
 306     memset(&phdr, 0, sizeof(Elf32_Phdr));
 307     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
 308     phdr.p_offset = cpu_convert_to_target32(begin, endian);
 309     phdr.p_paddr = 0;
 310     phdr.p_filesz = cpu_convert_to_target32(s->note_size, endian);
 311     phdr.p_memsz = cpu_convert_to_target32(s->note_size, endian);
 312     phdr.p_vaddr = 0;
 313
 314     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 315     if (ret < 0) {
 316         dump_error(s, "dump: failed to write program header table.\n");
 317         return -1;
 318     }
 319
 320     return 0;
 321 }
 322
 323 static int write_elf32_notes(DumpState *s)
 324 {
 325     CPUArchState *env;
 326     CPUState *cpu;
 327     int ret;
 328     int id;
 329
 330     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 331         cpu = ENV_GET_CPU(env);
 332         id = cpu_index(cpu);
 333         ret = cpu_write_elf32_note(fd_write_vmcore, env, id, s);
 334         if (ret < 0) {
 335             dump_error(s, "dump: failed to write elf notes.\n");
 336             return -1;
 337         }
 338     }
 339
 340     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 341         ret = cpu_write_elf32_qemunote(fd_write_vmcore, env, s);
 342         if (ret < 0) {
 343             dump_error(s, "dump: failed to write CPU status.\n");
 344             return -1;
 345         }
 346     }
 347
 348     return 0;
 349 }
 350
 351 static int write_elf_section(DumpState *s, int type)
 352 {
 353     Elf32_Shdr shdr32;
 354     Elf64_Shdr shdr64;
 355     int endian = s->dump_info.d_endian;
 356     int shdr_size;
 357     void *shdr;
 358     int ret;
 359
 360     if (type == 0) {
 361         shdr_size = sizeof(Elf32_Shdr);
 362         memset(&shdr32, 0, shdr_size);
 363         shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
 364         shdr = &shdr32;
 365     } else {
 366         shdr_size = sizeof(Elf64_Shdr);
 367         memset(&shdr64, 0, shdr_size);
 368         shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
 369         shdr = &shdr64;
 370     }
 371
 372     ret = fd_write_vmcore(&shdr, shdr_size, s);
 373     if (ret < 0) {
 374         dump_error(s, "dump: failed to write section header table.\n");
 375         return -1;
 376     }
 377
 378     return 0;
 379 }
 380
 381 static int write_data(DumpState *s, void *buf, int length)
 382 {
 383     int ret;
 384
 385     ret = fd_write_vmcore(buf, length, s);
 386     if (ret < 0) {
 387         dump_error(s, "dump: failed to save memory.\n");
 388         return -1;
 389     }
 390
 391     return 0;
 392 }
 393
 394 /* write the memroy to vmcore. 1 page per I/O. */
 395 static int write_memory(DumpState *s, RAMBlock *block, ram_addr_t start,
 396                         int64_t size)
 397 {
 398     int64_t i;
 399     int ret;
 400
 401     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
 402         ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
 403                          TARGET_PAGE_SIZE);
 404         if (ret < 0) {
 405             return ret;
 406         }
 407     }
 408
 409     if ((size % TARGET_PAGE_SIZE) != 0) {
 410         ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
 411                          size % TARGET_PAGE_SIZE);
 412         if (ret < 0) {
 413             return ret;
 414         }
 415     }
 416
 417     return 0;
 418 }
 419
 420 /* get the memory's offset in the vmcore */
 421 static hwaddr get_offset(hwaddr phys_addr,
 422                                      DumpState *s)
 423 {
 424     RAMBlock *block;
 425     hwaddr offset = s->memory_offset;
 426     int64_t size_in_block, start;
 427
 428     if (s->has_filter) {
 429         if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
 430             return -1;
 431         }
 432     }
 433
 434     QTAILQ_FOREACH(block, &ram_list.blocks, next) {
 435         if (s->has_filter) {
 436             if (block->offset >= s->begin + s->length ||
 437                 block->offset + block->length <= s->begin) {
 438                 /* This block is out of the range */
 439                 continue;
 440             }
 441
 442             if (s->begin <= block->offset) {
 443                 start = block->offset;
 444             } else {
 445                 start = s->begin;
 446             }
 447
 448             size_in_block = block->length - (start - block->offset);
 449             if (s->begin + s->length < block->offset + block->length) {
 450                 size_in_block -= block->offset + block->length -
 451                                  (s->begin + s->length);
 452             }
 453         } else {
 454             start = block->offset;
 455             size_in_block = block->length;
 456         }
 457
 458         if (phys_addr >= start && phys_addr < start + size_in_block) {
 459             return phys_addr - start + offset;
 460         }
 461
 462         offset += size_in_block;
 463     }
 464
 465     return -1;
 466 }
 467
 468 static int write_elf_loads(DumpState *s)
 469 {
 470     hwaddr offset;
 471     MemoryMapping *memory_mapping;
 472     uint32_t phdr_index = 1;
 473     int ret;
 474     uint32_t max_index;
 475
 476     if (s->have_section) {
 477         max_index = s->sh_info;
 478     } else {
 479         max_index = s->phdr_num;
 480     }
 481
 482     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
 483         offset = get_offset(memory_mapping->phys_addr, s);
 484         if (s->dump_info.d_class == ELFCLASS64) {
 485             ret = write_elf64_load(s, memory_mapping, phdr_index++, offset);
 486         } else {
 487             ret = write_elf32_load(s, memory_mapping, phdr_index++, offset);
 488         }
 489
 490         if (ret < 0) {
 491             return -1;
 492         }
 493
 494         if (phdr_index >= max_index) {
 495             break;
 496         }
 497     }
 498
 499     return 0;
 500 }
 501
 502 /* write elf header, PT_NOTE and elf note to vmcore. */
 503 static int dump_begin(DumpState *s)
 504 {
 505     int ret;
 506
 507     /*
 508      * the vmcore's format is:
 509      *   --------------
 510      *   |  elf header |
 511      *   --------------
 512      *   |  PT_NOTE    |
 513      *   --------------
 514      *   |  PT_LOAD    |
 515      *   --------------
 516      *   |  ......     |
 517      *   --------------
 518      *   |  PT_LOAD    |
 519      *   --------------
 520      *   |  sec_hdr    |
 521      *   --------------
 522      *   |  elf note   |
 523      *   --------------
 524      *   |  memory     |
 525      *   --------------
 526      *
 527      * we only know where the memory is saved after we write elf note into
 528      * vmcore.
 529      */
 530
 531     /* write elf header to vmcore */
 532     if (s->dump_info.d_class == ELFCLASS64) {
 533         ret = write_elf64_header(s);
 534     } else {
 535         ret = write_elf32_header(s);
 536     }
 537     if (ret < 0) {
 538         return -1;
 539     }
 540
 541     if (s->dump_info.d_class == ELFCLASS64) {
 542         /* write PT_NOTE to vmcore */
 543         if (write_elf64_note(s) < 0) {
 544             return -1;
 545         }
 546
 547         /* write all PT_LOAD to vmcore */
 548         if (write_elf_loads(s) < 0) {
 549             return -1;
 550         }
 551
 552         /* write section to vmcore */
 553         if (s->have_section) {
 554             if (write_elf_section(s, 1) < 0) {
 555                 return -1;
 556             }
 557         }
 558
 559         /* write notes to vmcore */
 560         if (write_elf64_notes(s) < 0) {
 561             return -1;
 562         }
 563
 564     } else {
 565         /* write PT_NOTE to vmcore */
 566         if (write_elf32_note(s) < 0) {
 567             return -1;
 568         }
 569
 570         /* write all PT_LOAD to vmcore */
 571         if (write_elf_loads(s) < 0) {
 572             return -1;
 573         }
 574
 575         /* write section to vmcore */
 576         if (s->have_section) {
 577             if (write_elf_section(s, 0) < 0) {
 578                 return -1;
 579             }
 580         }
 581
 582         /* write notes to vmcore */
 583         if (write_elf32_notes(s) < 0) {
 584             return -1;
 585         }
 586     }
 587
 588     return 0;
 589 }
 590
 591 /* write PT_LOAD to vmcore */
 592 static int dump_completed(DumpState *s)
 593 {
 594     dump_cleanup(s);
 595     return 0;
 596 }
 597
 598 static int get_next_block(DumpState *s, RAMBlock *block)
 599 {
 600     while (1) {
 601         block = QTAILQ_NEXT(block, next);
 602         if (!block) {
 603             /* no more block */
 604             return 1;
 605         }
 606
 607         s->start = 0;
 608         s->block = block;
 609         if (s->has_filter) {
 610             if (block->offset >= s->begin + s->length ||
 611                 block->offset + block->length <= s->begin) {
 612                 /* This block is out of the range */
 613                 continue;
 614             }
 615
 616             if (s->begin > block->offset) {
 617                 s->start = s->begin - block->offset;
 618             }
 619         }
 620
 621         return 0;
 622     }
 623 }
 624
 625 /* write all memory to vmcore */
 626 static int dump_iterate(DumpState *s)
 627 {
 628     RAMBlock *block;
 629     int64_t size;
 630     int ret;
 631
 632     while (1) {
 633         block = s->block;
 634
 635         size = block->length;
 636         if (s->has_filter) {
 637             size -= s->start;
 638             if (s->begin + s->length < block->offset + block->length) {
 639                 size -= block->offset + block->length - (s->begin + s->length);
 640             }
 641         }
 642         ret = write_memory(s, block, s->start, size);
 643         if (ret == -1) {
 644             return ret;
 645         }
 646
 647         ret = get_next_block(s, block);
 648         if (ret == 1) {
 649             dump_completed(s);
 650             return 0;
 651         }
 652     }
 653 }
 654
 655 static int create_vmcore(DumpState *s)
 656 {
 657     int ret;
 658
 659     ret = dump_begin(s);
 660     if (ret < 0) {
 661         return -1;
 662     }
 663
 664     ret = dump_iterate(s);
 665     if (ret < 0) {
 666         return -1;
 667     }
 668
 669     return 0;
 670 }
 671
 672 static ram_addr_t get_start_block(DumpState *s)
 673 {
 674     RAMBlock *block;
 675
 676     if (!s->has_filter) {
 677         s->block = QTAILQ_FIRST(&ram_list.blocks);
 678         return 0;
 679     }
 680
 681     QTAILQ_FOREACH(block, &ram_list.blocks, next) {
 682         if (block->offset >= s->begin + s->length ||
 683             block->offset + block->length <= s->begin) {
 684             /* This block is out of the range */
 685             continue;
 686         }
 687
 688         s->block = block;
 689         if (s->begin > block->offset) {
 690             s->start = s->begin - block->offset;
 691         } else {
 692             s->start = 0;
 693         }
 694         return s->start;
 695     }
 696
 697     return -1;
 698 }
 699
 700 static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
 701                      int64_t begin, int64_t length, Error **errp)
 702 {
 703     CPUArchState *env;
 704     int nr_cpus;
 705     int ret;
 706
 707     if (runstate_is_running()) {
 708         vm_stop(RUN_STATE_SAVE_VM);
 709         s->resume = true;
 710     } else {
 711         s->resume = false;
 712     }
 713
 714     s->errp = errp;
 715     s->fd = fd;
 716     s->has_filter = has_filter;
 717     s->begin = begin;
 718     s->length = length;
 719     s->start = get_start_block(s);
 720     if (s->start == -1) {
 721         error_set(errp, QERR_INVALID_PARAMETER, "begin");
 722         goto cleanup;
 723     }
 724
 725     /*
 726      * get dump info: endian, class and architecture.
 727      * If the target architecture is not supported, cpu_get_dump_info() will
 728      * return -1.
 729      *
 730      * if we use kvm, we should synchronize the register before we get dump
 731      * info.
 732      */
 733     nr_cpus = 0;
 734     for (env = first_cpu; env != NULL; env = env->next_cpu) {
 735         cpu_synchronize_state(env);
 736         nr_cpus++;
 737     }
 738
 739     ret = cpu_get_dump_info(&s->dump_info);
 740     if (ret < 0) {
 741         error_set(errp, QERR_UNSUPPORTED);
 742         goto cleanup;
 743     }
 744
 745     s->note_size = cpu_get_note_size(s->dump_info.d_class,
 746                                      s->dump_info.d_machine, nr_cpus);
 747     if (ret < 0) {
 748         error_set(errp, QERR_UNSUPPORTED);
 749         goto cleanup;
 750     }
 751
 752     /* get memory mapping */
 753     memory_mapping_list_init(&s->list);
 754     if (paging) {
 755         qemu_get_guest_memory_mapping(&s->list);
 756     } else {
 757         qemu_get_guest_simple_memory_mapping(&s->list);
 758     }
 759
 760     if (s->has_filter) {
 761         memory_mapping_filter(&s->list, s->begin, s->length);
 762     }
 763
 764     /*
 765      * calculate phdr_num
 766      *
 767      * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
 768      */
 769     s->phdr_num = 1; /* PT_NOTE */
 770     if (s->list.num < UINT16_MAX - 2) {
 771         s->phdr_num += s->list.num;
 772         s->have_section = false;
 773     } else {
 774         s->have_section = true;
 775         s->phdr_num = PN_XNUM;
 776         s->sh_info = 1; /* PT_NOTE */
 777
 778         /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
 779         if (s->list.num <= UINT32_MAX - 1) {
 780             s->sh_info += s->list.num;
 781         } else {
 782             s->sh_info = UINT32_MAX;
 783         }
 784     }
 785
 786     if (s->dump_info.d_class == ELFCLASS64) {
 787         if (s->have_section) {
 788             s->memory_offset = sizeof(Elf64_Ehdr) +
 789                                sizeof(Elf64_Phdr) * s->sh_info +
 790                                sizeof(Elf64_Shdr) + s->note_size;
 791         } else {
 792             s->memory_offset = sizeof(Elf64_Ehdr) +
 793                                sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;
 794         }
 795     } else {
 796         if (s->have_section) {
 797             s->memory_offset = sizeof(Elf32_Ehdr) +
 798                                sizeof(Elf32_Phdr) * s->sh_info +
 799                                sizeof(Elf32_Shdr) + s->note_size;
 800         } else {
 801             s->memory_offset = sizeof(Elf32_Ehdr) +
 802                                sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;
 803         }
 804     }
 805
 806     return 0;
 807
 808 cleanup:
 809     if (s->resume) {
 810         vm_start();
 811     }
 812
 813     return -1;
 814 }
 815
 816 void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
 817                            int64_t begin, bool has_length, int64_t length,
 818                            Error **errp)
 819 {
 820     const char *p;
 821     int fd = -1;
 822     DumpState *s;
 823     int ret;
 824
 825     if (has_begin && !has_length) {
 826         error_set(errp, QERR_MISSING_PARAMETER, "length");
 827         return;
 828     }
 829     if (!has_begin && has_length) {
 830         error_set(errp, QERR_MISSING_PARAMETER, "begin");
 831         return;
 832     }
 833
 834 #if !defined(WIN32)
 835     if (strstart(file, "fd:", &p)) {
 836         fd = monitor_get_fd(cur_mon, p, errp);
 837         if (fd == -1) {
 838             return;
 839         }
 840     }
 841 #endif
 842
 843     if  (strstart(file, "file:", &p)) {
 844         fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
 845         if (fd < 0) {
 846             error_set(errp, QERR_OPEN_FILE_FAILED, p);
 847             return;
 848         }
 849     }
 850
 851     if (fd == -1) {
 852         error_set(errp, QERR_INVALID_PARAMETER, "protocol");
 853         return;
 854     }
 855
 856     s = g_malloc(sizeof(DumpState));
 857
 858     ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
 859     if (ret < 0) {
 860         g_free(s);
 861         return;
 862     }
 863
 864     if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
 865         error_set(errp, QERR_IO_ERROR);
 866     }
 867
 868     g_free(s);
 869 }