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