qemu/dump.c
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   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 "sysemu/cpus.h"
  25#include "qapi/error.h"
  26#include "qmp-commands.h"
  27
  28#include <zlib.h>
  29#ifdef CONFIG_LZO
  30#include <lzo/lzo1x.h>
  31#endif
  32#ifdef CONFIG_SNAPPY
  33#include <snappy-c.h>
  34#endif
  35#ifndef ELF_MACHINE_UNAME
  36#define ELF_MACHINE_UNAME "Unknown"
  37#endif
  38
  39uint16_t cpu_to_dump16(DumpState *s, uint16_t val)
  40{
  41    if (s->dump_info.d_endian == ELFDATA2LSB) {
  42        val = cpu_to_le16(val);
  43    } else {
  44        val = cpu_to_be16(val);
  45    }
  46
  47    return val;
  48}
  49
  50uint32_t cpu_to_dump32(DumpState *s, uint32_t val)
  51{
  52    if (s->dump_info.d_endian == ELFDATA2LSB) {
  53        val = cpu_to_le32(val);
  54    } else {
  55        val = cpu_to_be32(val);
  56    }
  57
  58    return val;
  59}
  60
  61uint64_t cpu_to_dump64(DumpState *s, uint64_t val)
  62{
  63    if (s->dump_info.d_endian == ELFDATA2LSB) {
  64        val = cpu_to_le64(val);
  65    } else {
  66        val = cpu_to_be64(val);
  67    }
  68
  69    return val;
  70}
  71
  72static int dump_cleanup(DumpState *s)
  73{
  74    guest_phys_blocks_free(&s->guest_phys_blocks);
  75    memory_mapping_list_free(&s->list);
  76    close(s->fd);
  77    if (s->resume) {
  78        vm_start();
  79    }
  80
  81    return 0;
  82}
  83
  84static void dump_error(DumpState *s, const char *reason, Error **errp)
  85{
  86    dump_cleanup(s);
  87    error_setg(errp, "%s", reason);
  88}
  89
  90static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
  91{
  92    DumpState *s = opaque;
  93    size_t written_size;
  94
  95    written_size = qemu_write_full(s->fd, buf, size);
  96    if (written_size != size) {
  97        return -1;
  98    }
  99
 100    return 0;
 101}
 102
 103static void write_elf64_header(DumpState *s, Error **errp)
 104{
 105    Elf64_Ehdr elf_header;
 106    int ret;
 107
 108    memset(&elf_header, 0, sizeof(Elf64_Ehdr));
 109    memcpy(&elf_header, ELFMAG, SELFMAG);
 110    elf_header.e_ident[EI_CLASS] = ELFCLASS64;
 111    elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
 112    elf_header.e_ident[EI_VERSION] = EV_CURRENT;
 113    elf_header.e_type = cpu_to_dump16(s, ET_CORE);
 114    elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
 115    elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);
 116    elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
 117    elf_header.e_phoff = cpu_to_dump64(s, sizeof(Elf64_Ehdr));
 118    elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
 119    elf_header.e_phnum = cpu_to_dump16(s, s->phdr_num);
 120    if (s->have_section) {
 121        uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;
 122
 123        elf_header.e_shoff = cpu_to_dump64(s, shoff);
 124        elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
 125        elf_header.e_shnum = cpu_to_dump16(s, 1);
 126    }
 127
 128    ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
 129    if (ret < 0) {
 130        dump_error(s, "dump: failed to write elf header", errp);
 131    }
 132}
 133
 134static void write_elf32_header(DumpState *s, Error **errp)
 135{
 136    Elf32_Ehdr elf_header;
 137    int ret;
 138
 139    memset(&elf_header, 0, sizeof(Elf32_Ehdr));
 140    memcpy(&elf_header, ELFMAG, SELFMAG);
 141    elf_header.e_ident[EI_CLASS] = ELFCLASS32;
 142    elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
 143    elf_header.e_ident[EI_VERSION] = EV_CURRENT;
 144    elf_header.e_type = cpu_to_dump16(s, ET_CORE);
 145    elf_header.e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
 146    elf_header.e_version = cpu_to_dump32(s, EV_CURRENT);
 147    elf_header.e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
 148    elf_header.e_phoff = cpu_to_dump32(s, sizeof(Elf32_Ehdr));
 149    elf_header.e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
 150    elf_header.e_phnum = cpu_to_dump16(s, s->phdr_num);
 151    if (s->have_section) {
 152        uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;
 153
 154        elf_header.e_shoff = cpu_to_dump32(s, shoff);
 155        elf_header.e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
 156        elf_header.e_shnum = cpu_to_dump16(s, 1);
 157    }
 158
 159    ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
 160    if (ret < 0) {
 161        dump_error(s, "dump: failed to write elf header", errp);
 162    }
 163}
 164
 165static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
 166                             int phdr_index, hwaddr offset,
 167                             hwaddr filesz, Error **errp)
 168{
 169    Elf64_Phdr phdr;
 170    int ret;
 171
 172    memset(&phdr, 0, sizeof(Elf64_Phdr));
 173    phdr.p_type = cpu_to_dump32(s, PT_LOAD);
 174    phdr.p_offset = cpu_to_dump64(s, offset);
 175    phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
 176    phdr.p_filesz = cpu_to_dump64(s, filesz);
 177    phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
 178    phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr);
 179
 180    assert(memory_mapping->length >= filesz);
 181
 182    ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
 183    if (ret < 0) {
 184        dump_error(s, "dump: failed to write program header table", errp);
 185    }
 186}
 187
 188static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
 189                             int phdr_index, hwaddr offset,
 190                             hwaddr filesz, Error **errp)
 191{
 192    Elf32_Phdr phdr;
 193    int ret;
 194
 195    memset(&phdr, 0, sizeof(Elf32_Phdr));
 196    phdr.p_type = cpu_to_dump32(s, PT_LOAD);
 197    phdr.p_offset = cpu_to_dump32(s, offset);
 198    phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
 199    phdr.p_filesz = cpu_to_dump32(s, filesz);
 200    phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
 201    phdr.p_vaddr = cpu_to_dump32(s, memory_mapping->virt_addr);
 202
 203    assert(memory_mapping->length >= filesz);
 204
 205    ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 206    if (ret < 0) {
 207        dump_error(s, "dump: failed to write program header table", errp);
 208    }
 209}
 210
 211static void write_elf64_note(DumpState *s, Error **errp)
 212{
 213    Elf64_Phdr phdr;
 214    hwaddr begin = s->memory_offset - s->note_size;
 215    int ret;
 216
 217    memset(&phdr, 0, sizeof(Elf64_Phdr));
 218    phdr.p_type = cpu_to_dump32(s, PT_NOTE);
 219    phdr.p_offset = cpu_to_dump64(s, begin);
 220    phdr.p_paddr = 0;
 221    phdr.p_filesz = cpu_to_dump64(s, s->note_size);
 222    phdr.p_memsz = cpu_to_dump64(s, s->note_size);
 223    phdr.p_vaddr = 0;
 224
 225    ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
 226    if (ret < 0) {
 227        dump_error(s, "dump: failed to write program header table", errp);
 228    }
 229}
 230
 231static inline int cpu_index(CPUState *cpu)
 232{
 233    return cpu->cpu_index + 1;
 234}
 235
 236static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
 237                              Error **errp)
 238{
 239    CPUState *cpu;
 240    int ret;
 241    int id;
 242
 243    CPU_FOREACH(cpu) {
 244        id = cpu_index(cpu);
 245        ret = cpu_write_elf64_note(f, cpu, id, s);
 246        if (ret < 0) {
 247            dump_error(s, "dump: failed to write elf notes", errp);
 248            return;
 249        }
 250    }
 251
 252    CPU_FOREACH(cpu) {
 253        ret = cpu_write_elf64_qemunote(f, cpu, s);
 254        if (ret < 0) {
 255            dump_error(s, "dump: failed to write CPU status", errp);
 256            return;
 257        }
 258    }
 259}
 260
 261static void write_elf32_note(DumpState *s, Error **errp)
 262{
 263    hwaddr begin = s->memory_offset - s->note_size;
 264    Elf32_Phdr phdr;
 265    int ret;
 266
 267    memset(&phdr, 0, sizeof(Elf32_Phdr));
 268    phdr.p_type = cpu_to_dump32(s, PT_NOTE);
 269    phdr.p_offset = cpu_to_dump32(s, begin);
 270    phdr.p_paddr = 0;
 271    phdr.p_filesz = cpu_to_dump32(s, s->note_size);
 272    phdr.p_memsz = cpu_to_dump32(s, s->note_size);
 273    phdr.p_vaddr = 0;
 274
 275    ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
 276    if (ret < 0) {
 277        dump_error(s, "dump: failed to write program header table", errp);
 278    }
 279}
 280
 281static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
 282                              Error **errp)
 283{
 284    CPUState *cpu;
 285    int ret;
 286    int id;
 287
 288    CPU_FOREACH(cpu) {
 289        id = cpu_index(cpu);
 290        ret = cpu_write_elf32_note(f, cpu, id, s);
 291        if (ret < 0) {
 292            dump_error(s, "dump: failed to write elf notes", errp);
 293            return;
 294        }
 295    }
 296
 297    CPU_FOREACH(cpu) {
 298        ret = cpu_write_elf32_qemunote(f, cpu, s);
 299        if (ret < 0) {
 300            dump_error(s, "dump: failed to write CPU status", errp);
 301            return;
 302        }
 303    }
 304}
 305
 306static void write_elf_section(DumpState *s, int type, Error **errp)
 307{
 308    Elf32_Shdr shdr32;
 309    Elf64_Shdr shdr64;
 310    int shdr_size;
 311    void *shdr;
 312    int ret;
 313
 314    if (type == 0) {
 315        shdr_size = sizeof(Elf32_Shdr);
 316        memset(&shdr32, 0, shdr_size);
 317        shdr32.sh_info = cpu_to_dump32(s, s->sh_info);
 318        shdr = &shdr32;
 319    } else {
 320        shdr_size = sizeof(Elf64_Shdr);
 321        memset(&shdr64, 0, shdr_size);
 322        shdr64.sh_info = cpu_to_dump32(s, s->sh_info);
 323        shdr = &shdr64;
 324    }
 325
 326    ret = fd_write_vmcore(&shdr, shdr_size, s);
 327    if (ret < 0) {
 328        dump_error(s, "dump: failed to write section header table", errp);
 329    }
 330}
 331
 332static void write_data(DumpState *s, void *buf, int length, Error **errp)
 333{
 334    int ret;
 335
 336    ret = fd_write_vmcore(buf, length, s);
 337    if (ret < 0) {
 338        dump_error(s, "dump: failed to save memory", errp);
 339    }
 340}
 341
 342/* write the memory to vmcore. 1 page per I/O. */
 343static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
 344                         int64_t size, Error **errp)
 345{
 346    int64_t i;
 347    Error *local_err = NULL;
 348
 349    for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
 350        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
 351                   TARGET_PAGE_SIZE, &local_err);
 352        if (local_err) {
 353            error_propagate(errp, local_err);
 354            return;
 355        }
 356    }
 357
 358    if ((size % TARGET_PAGE_SIZE) != 0) {
 359        write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
 360                   size % TARGET_PAGE_SIZE, &local_err);
 361        if (local_err) {
 362            error_propagate(errp, local_err);
 363            return;
 364        }
 365    }
 366}
 367
 368/* get the memory's offset and size in the vmcore */
 369static void get_offset_range(hwaddr phys_addr,
 370                             ram_addr_t mapping_length,
 371                             DumpState *s,
 372                             hwaddr *p_offset,
 373                             hwaddr *p_filesz)
 374{
 375    GuestPhysBlock *block;
 376    hwaddr offset = s->memory_offset;
 377    int64_t size_in_block, start;
 378
 379    /* When the memory is not stored into vmcore, offset will be -1 */
 380    *p_offset = -1;
 381    *p_filesz = 0;
 382
 383    if (s->has_filter) {
 384        if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
 385            return;
 386        }
 387    }
 388
 389    QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
 390        if (s->has_filter) {
 391            if (block->target_start >= s->begin + s->length ||
 392                block->target_end <= s->begin) {
 393                /* This block is out of the range */
 394                continue;
 395            }
 396
 397            if (s->begin <= block->target_start) {
 398                start = block->target_start;
 399            } else {
 400                start = s->begin;
 401            }
 402
 403            size_in_block = block->target_end - start;
 404            if (s->begin + s->length < block->target_end) {
 405                size_in_block -= block->target_end - (s->begin + s->length);
 406            }
 407        } else {
 408            start = block->target_start;
 409            size_in_block = block->target_end - block->target_start;
 410        }
 411
 412        if (phys_addr >= start && phys_addr < start + size_in_block) {
 413            *p_offset = phys_addr - start + offset;
 414
 415            /* The offset range mapped from the vmcore file must not spill over
 416             * the GuestPhysBlock, clamp it. The rest of the mapping will be
 417             * zero-filled in memory at load time; see
 418             * <http://refspecs.linuxbase.org/elf/gabi4+/ch5.pheader.html>.
 419             */
 420            *p_filesz = phys_addr + mapping_length <= start + size_in_block ?
 421                        mapping_length :
 422                        size_in_block - (phys_addr - start);
 423            return;
 424        }
 425
 426        offset += size_in_block;
 427    }
 428}
 429
 430static void write_elf_loads(DumpState *s, Error **errp)
 431{
 432    hwaddr offset, filesz;
 433    MemoryMapping *memory_mapping;
 434    uint32_t phdr_index = 1;
 435    uint32_t max_index;
 436    Error *local_err = NULL;
 437
 438    if (s->have_section) {
 439        max_index = s->sh_info;
 440    } else {
 441        max_index = s->phdr_num;
 442    }
 443
 444    QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
 445        get_offset_range(memory_mapping->phys_addr,
 446                         memory_mapping->length,
 447                         s, &offset, &filesz);
 448        if (s->dump_info.d_class == ELFCLASS64) {
 449            write_elf64_load(s, memory_mapping, phdr_index++, offset,
 450                             filesz, &local_err);
 451        } else {
 452            write_elf32_load(s, memory_mapping, phdr_index++, offset,
 453                             filesz, &local_err);
 454        }
 455
 456        if (local_err) {
 457            error_propagate(errp, local_err);
 458            return;
 459        }
 460
 461        if (phdr_index >= max_index) {
 462            break;
 463        }
 464    }
 465}
 466
 467/* write elf header, PT_NOTE and elf note to vmcore. */
 468static void dump_begin(DumpState *s, Error **errp)
 469{
 470    Error *local_err = NULL;
 471
 472    /*
 473     * the vmcore's format is:
 474     *   --------------
 475     *   |  elf header |
 476     *   --------------
 477     *   |  PT_NOTE    |
 478     *   --------------
 479     *   |  PT_LOAD    |
 480     *   --------------
 481     *   |  ......     |
 482     *   --------------
 483     *   |  PT_LOAD    |
 484     *   --------------
 485     *   |  sec_hdr    |
 486     *   --------------
 487     *   |  elf note   |
 488     *   --------------
 489     *   |  memory     |
 490     *   --------------
 491     *
 492     * we only know where the memory is saved after we write elf note into
 493     * vmcore.
 494     */
 495
 496    /* write elf header to vmcore */
 497    if (s->dump_info.d_class == ELFCLASS64) {
 498        write_elf64_header(s, &local_err);
 499    } else {
 500        write_elf32_header(s, &local_err);
 501    }
 502    if (local_err) {
 503        error_propagate(errp, local_err);
 504        return;
 505    }
 506
 507    if (s->dump_info.d_class == ELFCLASS64) {
 508        /* write PT_NOTE to vmcore */
 509        write_elf64_note(s, &local_err);
 510        if (local_err) {
 511            error_propagate(errp, local_err);
 512            return;
 513        }
 514
 515        /* write all PT_LOAD to vmcore */
 516        write_elf_loads(s, &local_err);
 517        if (local_err) {
 518            error_propagate(errp, local_err);
 519            return;
 520        }
 521
 522        /* write section to vmcore */
 523        if (s->have_section) {
 524            write_elf_section(s, 1, &local_err);
 525            if (local_err) {
 526                error_propagate(errp, local_err);
 527                return;
 528            }
 529        }
 530
 531        /* write notes to vmcore */
 532        write_elf64_notes(fd_write_vmcore, s, &local_err);
 533        if (local_err) {
 534            error_propagate(errp, local_err);
 535            return;
 536        }
 537    } else {
 538        /* write PT_NOTE to vmcore */
 539        write_elf32_note(s, &local_err);
 540        if (local_err) {
 541            error_propagate(errp, local_err);
 542            return;
 543        }
 544
 545        /* write all PT_LOAD to vmcore */
 546        write_elf_loads(s, &local_err);
 547        if (local_err) {
 548            error_propagate(errp, local_err);
 549            return;
 550        }
 551
 552        /* write section to vmcore */
 553        if (s->have_section) {
 554            write_elf_section(s, 0, &local_err);
 555            if (local_err) {
 556                error_propagate(errp, local_err);
 557                return;
 558            }
 559        }
 560
 561        /* write notes to vmcore */
 562        write_elf32_notes(fd_write_vmcore, s, &local_err);
 563        if (local_err) {
 564            error_propagate(errp, local_err);
 565            return;
 566        }
 567    }
 568}
 569
 570static void dump_completed(DumpState *s)
 571{
 572    dump_cleanup(s);
 573}
 574
 575static int get_next_block(DumpState *s, GuestPhysBlock *block)
 576{
 577    while (1) {
 578        block = QTAILQ_NEXT(block, next);
 579        if (!block) {
 580            /* no more block */
 581            return 1;
 582        }
 583
 584        s->start = 0;
 585        s->next_block = block;
 586        if (s->has_filter) {
 587            if (block->target_start >= s->begin + s->length ||
 588                block->target_end <= s->begin) {
 589                /* This block is out of the range */
 590                continue;
 591            }
 592
 593            if (s->begin > block->target_start) {
 594                s->start = s->begin - block->target_start;
 595            }
 596        }
 597
 598        return 0;
 599    }
 600}
 601
 602/* write all memory to vmcore */
 603static void dump_iterate(DumpState *s, Error **errp)
 604{
 605    GuestPhysBlock *block;
 606    int64_t size;
 607    Error *local_err = NULL;
 608
 609    do {
 610        block = s->next_block;
 611
 612        size = block->target_end - block->target_start;
 613        if (s->has_filter) {
 614            size -= s->start;
 615            if (s->begin + s->length < block->target_end) {
 616                size -= block->target_end - (s->begin + s->length);
 617            }
 618        }
 619        write_memory(s, block, s->start, size, &local_err);
 620        if (local_err) {
 621            error_propagate(errp, local_err);
 622            return;
 623        }
 624
 625    } while (!get_next_block(s, block));
 626
 627    dump_completed(s);
 628}
 629
 630static void create_vmcore(DumpState *s, Error **errp)
 631{
 632    Error *local_err = NULL;
 633
 634    dump_begin(s, &local_err);
 635    if (local_err) {
 636        error_propagate(errp, local_err);
 637        return;
 638    }
 639
 640    dump_iterate(s, errp);
 641}
 642
 643static int write_start_flat_header(int fd)
 644{
 645    MakedumpfileHeader *mh;
 646    int ret = 0;
 647
 648    QEMU_BUILD_BUG_ON(sizeof *mh > MAX_SIZE_MDF_HEADER);
 649    mh = g_malloc0(MAX_SIZE_MDF_HEADER);
 650
 651    memcpy(mh->signature, MAKEDUMPFILE_SIGNATURE,
 652           MIN(sizeof mh->signature, sizeof MAKEDUMPFILE_SIGNATURE));
 653
 654    mh->type = cpu_to_be64(TYPE_FLAT_HEADER);
 655    mh->version = cpu_to_be64(VERSION_FLAT_HEADER);
 656
 657    size_t written_size;
 658    written_size = qemu_write_full(fd, mh, MAX_SIZE_MDF_HEADER);
 659    if (written_size != MAX_SIZE_MDF_HEADER) {
 660        ret = -1;
 661    }
 662
 663    g_free(mh);
 664    return ret;
 665}
 666
 667static int write_end_flat_header(int fd)
 668{
 669    MakedumpfileDataHeader mdh;
 670
 671    mdh.offset = END_FLAG_FLAT_HEADER;
 672    mdh.buf_size = END_FLAG_FLAT_HEADER;
 673
 674    size_t written_size;
 675    written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
 676    if (written_size != sizeof(mdh)) {
 677        return -1;
 678    }
 679
 680    return 0;
 681}
 682
 683static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
 684{
 685    size_t written_size;
 686    MakedumpfileDataHeader mdh;
 687
 688    mdh.offset = cpu_to_be64(offset);
 689    mdh.buf_size = cpu_to_be64(size);
 690
 691    written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
 692    if (written_size != sizeof(mdh)) {
 693        return -1;
 694    }
 695
 696    written_size = qemu_write_full(fd, buf, size);
 697    if (written_size != size) {
 698        return -1;
 699    }
 700
 701    return 0;
 702}
 703
 704static int buf_write_note(const void *buf, size_t size, void *opaque)
 705{
 706    DumpState *s = opaque;
 707
 708    /* note_buf is not enough */
 709    if (s->note_buf_offset + size > s->note_size) {
 710        return -1;
 711    }
 712
 713    memcpy(s->note_buf + s->note_buf_offset, buf, size);
 714
 715    s->note_buf_offset += size;
 716
 717    return 0;
 718}
 719
 720/* write common header, sub header and elf note to vmcore */
 721static void create_header32(DumpState *s, Error **errp)
 722{
 723    DiskDumpHeader32 *dh = NULL;
 724    KdumpSubHeader32 *kh = NULL;
 725    size_t size;
 726    uint32_t block_size;
 727    uint32_t sub_hdr_size;
 728    uint32_t bitmap_blocks;
 729    uint32_t status = 0;
 730    uint64_t offset_note;
 731    Error *local_err = NULL;
 732
 733    /* write common header, the version of kdump-compressed format is 6th */
 734    size = sizeof(DiskDumpHeader32);
 735    dh = g_malloc0(size);
 736
 737    strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
 738    dh->header_version = cpu_to_dump32(s, 6);
 739    block_size = TARGET_PAGE_SIZE;
 740    dh->block_size = cpu_to_dump32(s, block_size);
 741    sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
 742    sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
 743    dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
 744    /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
 745    dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
 746    dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
 747    bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
 748    dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
 749    strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
 750
 751    if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
 752        status |= DUMP_DH_COMPRESSED_ZLIB;
 753    }
 754#ifdef CONFIG_LZO
 755    if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
 756        status |= DUMP_DH_COMPRESSED_LZO;
 757    }
 758#endif
 759#ifdef CONFIG_SNAPPY
 760    if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
 761        status |= DUMP_DH_COMPRESSED_SNAPPY;
 762    }
 763#endif
 764    dh->status = cpu_to_dump32(s, status);
 765
 766    if (write_buffer(s->fd, 0, dh, size) < 0) {
 767        dump_error(s, "dump: failed to write disk dump header", errp);
 768        goto out;
 769    }
 770
 771    /* write sub header */
 772    size = sizeof(KdumpSubHeader32);
 773    kh = g_malloc0(size);
 774
 775    /* 64bit max_mapnr_64 */
 776    kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
 777    kh->phys_base = cpu_to_dump32(s, PHYS_BASE);
 778    kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
 779
 780    offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
 781    kh->offset_note = cpu_to_dump64(s, offset_note);
 782    kh->note_size = cpu_to_dump32(s, s->note_size);
 783
 784    if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
 785                     block_size, kh, size) < 0) {
 786        dump_error(s, "dump: failed to write kdump sub header", errp);
 787        goto out;
 788    }
 789
 790    /* write note */
 791    s->note_buf = g_malloc0(s->note_size);
 792    s->note_buf_offset = 0;
 793
 794    /* use s->note_buf to store notes temporarily */
 795    write_elf32_notes(buf_write_note, s, &local_err);
 796    if (local_err) {
 797        error_propagate(errp, local_err);
 798        goto out;
 799    }
 800    if (write_buffer(s->fd, offset_note, s->note_buf,
 801                     s->note_size) < 0) {
 802        dump_error(s, "dump: failed to write notes", errp);
 803        goto out;
 804    }
 805
 806    /* get offset of dump_bitmap */
 807    s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
 808                             block_size;
 809
 810    /* get offset of page */
 811    s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
 812                     block_size;
 813
 814out:
 815    g_free(dh);
 816    g_free(kh);
 817    g_free(s->note_buf);
 818}
 819
 820/* write common header, sub header and elf note to vmcore */
 821static void create_header64(DumpState *s, Error **errp)
 822{
 823    DiskDumpHeader64 *dh = NULL;
 824    KdumpSubHeader64 *kh = NULL;
 825    size_t size;
 826    uint32_t block_size;
 827    uint32_t sub_hdr_size;
 828    uint32_t bitmap_blocks;
 829    uint32_t status = 0;
 830    uint64_t offset_note;
 831    Error *local_err = NULL;
 832
 833    /* write common header, the version of kdump-compressed format is 6th */
 834    size = sizeof(DiskDumpHeader64);
 835    dh = g_malloc0(size);
 836
 837    strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
 838    dh->header_version = cpu_to_dump32(s, 6);
 839    block_size = TARGET_PAGE_SIZE;
 840    dh->block_size = cpu_to_dump32(s, block_size);
 841    sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
 842    sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
 843    dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
 844    /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
 845    dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
 846    dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
 847    bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
 848    dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
 849    strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
 850
 851    if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
 852        status |= DUMP_DH_COMPRESSED_ZLIB;
 853    }
 854#ifdef CONFIG_LZO
 855    if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
 856        status |= DUMP_DH_COMPRESSED_LZO;
 857    }
 858#endif
 859#ifdef CONFIG_SNAPPY
 860    if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
 861        status |= DUMP_DH_COMPRESSED_SNAPPY;
 862    }
 863#endif
 864    dh->status = cpu_to_dump32(s, status);
 865
 866    if (write_buffer(s->fd, 0, dh, size) < 0) {
 867        dump_error(s, "dump: failed to write disk dump header", errp);
 868        goto out;
 869    }
 870
 871    /* write sub header */
 872    size = sizeof(KdumpSubHeader64);
 873    kh = g_malloc0(size);
 874
 875    /* 64bit max_mapnr_64 */
 876    kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
 877    kh->phys_base = cpu_to_dump64(s, PHYS_BASE);
 878    kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
 879
 880    offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
 881    kh->offset_note = cpu_to_dump64(s, offset_note);
 882    kh->note_size = cpu_to_dump64(s, s->note_size);
 883
 884    if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
 885                     block_size, kh, size) < 0) {
 886        dump_error(s, "dump: failed to write kdump sub header", errp);
 887        goto out;
 888    }
 889
 890    /* write note */
 891    s->note_buf = g_malloc0(s->note_size);
 892    s->note_buf_offset = 0;
 893
 894    /* use s->note_buf to store notes temporarily */
 895    write_elf64_notes(buf_write_note, s, &local_err);
 896    if (local_err) {
 897        error_propagate(errp, local_err);
 898        goto out;
 899    }
 900
 901    if (write_buffer(s->fd, offset_note, s->note_buf,
 902                     s->note_size) < 0) {
 903        dump_error(s, "dump: failed to write notes", errp);
 904        goto out;
 905    }
 906
 907    /* get offset of dump_bitmap */
 908    s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
 909                             block_size;
 910
 911    /* get offset of page */
 912    s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
 913                     block_size;
 914
 915out:
 916    g_free(dh);
 917    g_free(kh);
 918    g_free(s->note_buf);
 919}
 920
 921static void write_dump_header(DumpState *s, Error **errp)
 922{
 923     Error *local_err = NULL;
 924
 925    if (s->dump_info.d_class == ELFCLASS32) {
 926        create_header32(s, &local_err);
 927    } else {
 928        create_header64(s, &local_err);
 929    }
 930    if (local_err) {
 931        error_propagate(errp, local_err);
 932    }
 933}
 934
 935/*
 936 * set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
 937 * rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
 938 * set_dump_bitmap will always leave the recently set bit un-sync. And setting
 939 * (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
 940 * vmcore, ie. synchronizing un-sync bit into vmcore.
 941 */
 942static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
 943                           uint8_t *buf, DumpState *s)
 944{
 945    off_t old_offset, new_offset;
 946    off_t offset_bitmap1, offset_bitmap2;
 947    uint32_t byte, bit;
 948
 949    /* should not set the previous place */
 950    assert(last_pfn <= pfn);
 951
 952    /*
 953     * if the bit needed to be set is not cached in buf, flush the data in buf
 954     * to vmcore firstly.
 955     * making new_offset be bigger than old_offset can also sync remained data
 956     * into vmcore.
 957     */
 958    old_offset = BUFSIZE_BITMAP * (last_pfn / PFN_BUFBITMAP);
 959    new_offset = BUFSIZE_BITMAP * (pfn / PFN_BUFBITMAP);
 960
 961    while (old_offset < new_offset) {
 962        /* calculate the offset and write dump_bitmap */
 963        offset_bitmap1 = s->offset_dump_bitmap + old_offset;
 964        if (write_buffer(s->fd, offset_bitmap1, buf,
 965                         BUFSIZE_BITMAP) < 0) {
 966            return -1;
 967        }
 968
 969        /* dump level 1 is chosen, so 1st and 2nd bitmap are same */
 970        offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
 971                         old_offset;
 972        if (write_buffer(s->fd, offset_bitmap2, buf,
 973                         BUFSIZE_BITMAP) < 0) {
 974            return -1;
 975        }
 976
 977        memset(buf, 0, BUFSIZE_BITMAP);
 978        old_offset += BUFSIZE_BITMAP;
 979    }
 980
 981    /* get the exact place of the bit in the buf, and set it */
 982    byte = (pfn % PFN_BUFBITMAP) / CHAR_BIT;
 983    bit = (pfn % PFN_BUFBITMAP) % CHAR_BIT;
 984    if (value) {
 985        buf[byte] |= 1u << bit;
 986    } else {
 987        buf[byte] &= ~(1u << bit);
 988    }
 989
 990    return 0;
 991}
 992
 993/*
 994 * exam every page and return the page frame number and the address of the page.
 995 * bufptr can be NULL. note: the blocks here is supposed to reflect guest-phys
 996 * blocks, so block->target_start and block->target_end should be interal
 997 * multiples of the target page size.
 998 */
 999static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
1000                          uint8_t **bufptr, DumpState *s)
1001{
1002    GuestPhysBlock *block = *blockptr;
1003    hwaddr addr;
1004    uint8_t *buf;
1005
1006    /* block == NULL means the start of the iteration */
1007    if (!block) {
1008        block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
1009        *blockptr = block;
1010        assert((block->target_start & ~TARGET_PAGE_MASK) == 0);
1011        assert((block->target_end & ~TARGET_PAGE_MASK) == 0);
1012        *pfnptr = paddr_to_pfn(block->target_start);
1013        if (bufptr) {
1014            *bufptr = block->host_addr;
1015        }
1016        return true;
1017    }
1018
1019    *pfnptr = *pfnptr + 1;
1020    addr = pfn_to_paddr(*pfnptr);
1021
1022    if ((addr >= block->target_start) &&
1023        (addr + TARGET_PAGE_SIZE <= block->target_end)) {
1024        buf = block->host_addr + (addr - block->target_start);
1025    } else {
1026        /* the next page is in the next block */
1027        block = QTAILQ_NEXT(block, next);
1028        *blockptr = block;
1029        if (!block) {
1030            return false;
1031        }
1032        assert((block->target_start & ~TARGET_PAGE_MASK) == 0);
1033        assert((block->target_end & ~TARGET_PAGE_MASK) == 0);
1034        *pfnptr = paddr_to_pfn(block->target_start);
1035        buf = block->host_addr;
1036    }
1037
1038    if (bufptr) {
1039        *bufptr = buf;
1040    }
1041
1042    return true;
1043}
1044
1045static void write_dump_bitmap(DumpState *s, Error **errp)
1046{
1047    int ret = 0;
1048    uint64_t last_pfn, pfn;
1049    void *dump_bitmap_buf;
1050    size_t num_dumpable;
1051    GuestPhysBlock *block_iter = NULL;
1052
1053    /* dump_bitmap_buf is used to store dump_bitmap temporarily */
1054    dump_bitmap_buf = g_malloc0(BUFSIZE_BITMAP);
1055
1056    num_dumpable = 0;
1057    last_pfn = 0;
1058
1059    /*
1060     * exam memory page by page, and set the bit in dump_bitmap corresponded
1061     * to the existing page.
1062     */
1063    while (get_next_page(&block_iter, &pfn, NULL, s)) {
1064        ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
1065        if (ret < 0) {
1066            dump_error(s, "dump: failed to set dump_bitmap", errp);
1067            goto out;
1068        }
1069
1070        last_pfn = pfn;
1071        num_dumpable++;
1072    }
1073
1074    /*
1075     * set_dump_bitmap will always leave the recently set bit un-sync. Here we
1076     * set last_pfn + PFN_BUFBITMAP to 0 and those set but un-sync bit will be
1077     * synchronized into vmcore.
1078     */
1079    if (num_dumpable > 0) {
1080        ret = set_dump_bitmap(last_pfn, last_pfn + PFN_BUFBITMAP, false,
1081                              dump_bitmap_buf, s);
1082        if (ret < 0) {
1083            dump_error(s, "dump: failed to sync dump_bitmap", errp);
1084            goto out;
1085        }
1086    }
1087
1088    /* number of dumpable pages that will be dumped later */
1089    s->num_dumpable = num_dumpable;
1090
1091out:
1092    g_free(dump_bitmap_buf);
1093}
1094
1095static void prepare_data_cache(DataCache *data_cache, DumpState *s,
1096                               off_t offset)
1097{
1098    data_cache->fd = s->fd;
1099    data_cache->data_size = 0;
1100    data_cache->buf_size = BUFSIZE_DATA_CACHE;
1101    data_cache->buf = g_malloc0(BUFSIZE_DATA_CACHE);
1102    data_cache->offset = offset;
1103}
1104
1105static int write_cache(DataCache *dc, const void *buf, size_t size,
1106                       bool flag_sync)
1107{
1108    /*
1109     * dc->buf_size should not be less than size, otherwise dc will never be
1110     * enough
1111     */
1112    assert(size <= dc->buf_size);
1113
1114    /*
1115     * if flag_sync is set, synchronize data in dc->buf into vmcore.
1116     * otherwise check if the space is enough for caching data in buf, if not,
1117     * write the data in dc->buf to dc->fd and reset dc->buf
1118     */
1119    if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
1120        (flag_sync && dc->data_size > 0)) {
1121        if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) {
1122            return -1;
1123        }
1124
1125        dc->offset += dc->data_size;
1126        dc->data_size = 0;
1127    }
1128
1129    if (!flag_sync) {
1130        memcpy(dc->buf + dc->data_size, buf, size);
1131        dc->data_size += size;
1132    }
1133
1134    return 0;
1135}
1136
1137static void free_data_cache(DataCache *data_cache)
1138{
1139    g_free(data_cache->buf);
1140}
1141
1142static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
1143{
1144    switch (flag_compress) {
1145    case DUMP_DH_COMPRESSED_ZLIB:
1146        return compressBound(page_size);
1147
1148    case DUMP_DH_COMPRESSED_LZO:
1149        /*
1150         * LZO will expand incompressible data by a little amount. Please check
1151         * the following URL to see the expansion calculation:
1152         * http://www.oberhumer.com/opensource/lzo/lzofaq.php
1153         */
1154        return page_size + page_size / 16 + 64 + 3;
1155
1156#ifdef CONFIG_SNAPPY
1157    case DUMP_DH_COMPRESSED_SNAPPY:
1158        return snappy_max_compressed_length(page_size);
1159#endif
1160    }
1161    return 0;
1162}
1163
1164/*
1165 * check if the page is all 0
1166 */
1167static inline bool is_zero_page(const uint8_t *buf, size_t page_size)
1168{
1169    return buffer_is_zero(buf, page_size);
1170}
1171
1172static void write_dump_pages(DumpState *s, Error **errp)
1173{
1174    int ret = 0;
1175    DataCache page_desc, page_data;
1176    size_t len_buf_out, size_out;
1177#ifdef CONFIG_LZO
1178    lzo_bytep wrkmem = NULL;
1179#endif
1180    uint8_t *buf_out = NULL;
1181    off_t offset_desc, offset_data;
1182    PageDescriptor pd, pd_zero;
1183    uint8_t *buf;
1184    GuestPhysBlock *block_iter = NULL;
1185    uint64_t pfn_iter;
1186
1187    /* get offset of page_desc and page_data in dump file */
1188    offset_desc = s->offset_page;
1189    offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
1190
1191    prepare_data_cache(&page_desc, s, offset_desc);
1192    prepare_data_cache(&page_data, s, offset_data);
1193
1194    /* prepare buffer to store compressed data */
1195    len_buf_out = get_len_buf_out(TARGET_PAGE_SIZE, s->flag_compress);
1196    assert(len_buf_out != 0);
1197
1198#ifdef CONFIG_LZO
1199    wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
1200#endif
1201
1202    buf_out = g_malloc(len_buf_out);
1203
1204    /*
1205     * init zero page's page_desc and page_data, because every zero page
1206     * uses the same page_data
1207     */
1208    pd_zero.size = cpu_to_dump32(s, TARGET_PAGE_SIZE);
1209    pd_zero.flags = cpu_to_dump32(s, 0);
1210    pd_zero.offset = cpu_to_dump64(s, offset_data);
1211    pd_zero.page_flags = cpu_to_dump64(s, 0);
1212    buf = g_malloc0(TARGET_PAGE_SIZE);
1213    ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
1214    g_free(buf);
1215    if (ret < 0) {
1216        dump_error(s, "dump: failed to write page data (zero page)", errp);
1217        goto out;
1218    }
1219
1220    offset_data += TARGET_PAGE_SIZE;
1221
1222    /*
1223     * dump memory to vmcore page by page. zero page will all be resided in the
1224     * first page of page section
1225     */
1226    while (get_next_page(&block_iter, &pfn_iter, &buf, s)) {
1227        /* check zero page */
1228        if (is_zero_page(buf, TARGET_PAGE_SIZE)) {
1229            ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
1230                              false);
1231            if (ret < 0) {
1232                dump_error(s, "dump: failed to write page desc", errp);
1233                goto out;
1234            }
1235        } else {
1236            /*
1237             * not zero page, then:
1238             * 1. compress the page
1239             * 2. write the compressed page into the cache of page_data
1240             * 3. get page desc of the compressed page and write it into the
1241             *    cache of page_desc
1242             *
1243             * only one compression format will be used here, for
1244             * s->flag_compress is set. But when compression fails to work,
1245             * we fall back to save in plaintext.
1246             */
1247             size_out = len_buf_out;
1248             if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
1249                    (compress2(buf_out, (uLongf *)&size_out, buf,
1250                               TARGET_PAGE_SIZE, Z_BEST_SPEED) == Z_OK) &&
1251                    (size_out < TARGET_PAGE_SIZE)) {
1252                pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_ZLIB);
1253                pd.size  = cpu_to_dump32(s, size_out);
1254
1255                ret = write_cache(&page_data, buf_out, size_out, false);
1256                if (ret < 0) {
1257                    dump_error(s, "dump: failed to write page data", errp);
1258                    goto out;
1259                }
1260#ifdef CONFIG_LZO
1261            } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
1262                    (lzo1x_1_compress(buf, TARGET_PAGE_SIZE, buf_out,
1263                    (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
1264                    (size_out < TARGET_PAGE_SIZE)) {
1265                pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_LZO);
1266                pd.size  = cpu_to_dump32(s, size_out);
1267
1268                ret = write_cache(&page_data, buf_out, size_out, false);
1269                if (ret < 0) {
1270                    dump_error(s, "dump: failed to write page data", errp);
1271                    goto out;
1272                }
1273#endif
1274#ifdef CONFIG_SNAPPY
1275            } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
1276                    (snappy_compress((char *)buf, TARGET_PAGE_SIZE,
1277                    (char *)buf_out, &size_out) == SNAPPY_OK) &&
1278                    (size_out < TARGET_PAGE_SIZE)) {
1279                pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_SNAPPY);
1280                pd.size  = cpu_to_dump32(s, size_out);
1281
1282                ret = write_cache(&page_data, buf_out, size_out, false);
1283                if (ret < 0) {
1284                    dump_error(s, "dump: failed to write page data", errp);
1285                    goto out;
1286                }
1287#endif
1288            } else {
1289                /*
1290                 * fall back to save in plaintext, size_out should be
1291                 * assigned TARGET_PAGE_SIZE
1292                 */
1293                pd.flags = cpu_to_dump32(s, 0);
1294                size_out = TARGET_PAGE_SIZE;
1295                pd.size = cpu_to_dump32(s, size_out);
1296
1297                ret = write_cache(&page_data, buf, TARGET_PAGE_SIZE, false);
1298                if (ret < 0) {
1299                    dump_error(s, "dump: failed to write page data", errp);
1300                    goto out;
1301                }
1302            }
1303
1304            /* get and write page desc here */
1305            pd.page_flags = cpu_to_dump64(s, 0);
1306            pd.offset = cpu_to_dump64(s, offset_data);
1307            offset_data += size_out;
1308
1309            ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
1310            if (ret < 0) {
1311                dump_error(s, "dump: failed to write page desc", errp);
1312                goto out;
1313            }
1314        }
1315    }
1316
1317    ret = write_cache(&page_desc, NULL, 0, true);
1318    if (ret < 0) {
1319        dump_error(s, "dump: failed to sync cache for page_desc", errp);
1320        goto out;
1321    }
1322    ret = write_cache(&page_data, NULL, 0, true);
1323    if (ret < 0) {
1324        dump_error(s, "dump: failed to sync cache for page_data", errp);
1325        goto out;
1326    }
1327
1328out:
1329    free_data_cache(&page_desc);
1330    free_data_cache(&page_data);
1331
1332#ifdef CONFIG_LZO
1333    g_free(wrkmem);
1334#endif
1335
1336    g_free(buf_out);
1337}
1338
1339static void create_kdump_vmcore(DumpState *s, Error **errp)
1340{
1341    int ret;
1342    Error *local_err = NULL;
1343
1344    /*
1345     * the kdump-compressed format is:
1346     *                                               File offset
1347     *  +------------------------------------------+ 0x0
1348     *  |    main header (struct disk_dump_header) |
1349     *  |------------------------------------------+ block 1
1350     *  |    sub header (struct kdump_sub_header)  |
1351     *  |------------------------------------------+ block 2
1352     *  |            1st-dump_bitmap               |
1353     *  |------------------------------------------+ block 2 + X blocks
1354     *  |            2nd-dump_bitmap               | (aligned by block)
1355     *  |------------------------------------------+ block 2 + 2 * X blocks
1356     *  |  page desc for pfn 0 (struct page_desc)  | (aligned by block)
1357     *  |  page desc for pfn 1 (struct page_desc)  |
1358     *  |                    :                     |
1359     *  |------------------------------------------| (not aligned by block)
1360     *  |         page data (pfn 0)                |
1361     *  |         page data (pfn 1)                |
1362     *  |                    :                     |
1363     *  +------------------------------------------+
1364     */
1365
1366    ret = write_start_flat_header(s->fd);
1367    if (ret < 0) {
1368        dump_error(s, "dump: failed to write start flat header", errp);
1369        return;
1370    }
1371
1372    write_dump_header(s, &local_err);
1373    if (local_err) {
1374        error_propagate(errp, local_err);
1375        return;
1376    }
1377
1378    write_dump_bitmap(s, &local_err);
1379    if (local_err) {
1380        error_propagate(errp, local_err);
1381        return;
1382    }
1383
1384    write_dump_pages(s, &local_err);
1385    if (local_err) {
1386        error_propagate(errp, local_err);
1387        return;
1388    }
1389
1390    ret = write_end_flat_header(s->fd);
1391    if (ret < 0) {
1392        dump_error(s, "dump: failed to write end flat header", errp);
1393        return;
1394    }
1395
1396    dump_completed(s);
1397}
1398
1399static ram_addr_t get_start_block(DumpState *s)
1400{
1401    GuestPhysBlock *block;
1402
1403    if (!s->has_filter) {
1404        s->next_block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
1405        return 0;
1406    }
1407
1408    QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
1409        if (block->target_start >= s->begin + s->length ||
1410            block->target_end <= s->begin) {
1411            /* This block is out of the range */
1412            continue;
1413        }
1414
1415        s->next_block = block;
1416        if (s->begin > block->target_start) {
1417            s->start = s->begin - block->target_start;
1418        } else {
1419            s->start = 0;
1420        }
1421        return s->start;
1422    }
1423
1424    return -1;
1425}
1426
1427static void get_max_mapnr(DumpState *s)
1428{
1429    GuestPhysBlock *last_block;
1430
1431    last_block = QTAILQ_LAST(&s->guest_phys_blocks.head, GuestPhysBlockHead);
1432    s->max_mapnr = paddr_to_pfn(last_block->target_end);
1433}
1434
1435static void dump_init(DumpState *s, int fd, bool has_format,
1436                      DumpGuestMemoryFormat format, bool paging, bool has_filter,
1437                      int64_t begin, int64_t length, Error **errp)
1438{
1439    CPUState *cpu;
1440    int nr_cpus;
1441    Error *err = NULL;
1442    int ret;
1443
1444    /* kdump-compressed is conflict with paging and filter */
1445    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1446        assert(!paging && !has_filter);
1447    }
1448
1449    if (runstate_is_running()) {
1450        vm_stop(RUN_STATE_SAVE_VM);
1451        s->resume = true;
1452    } else {
1453        s->resume = false;
1454    }
1455
1456    /* If we use KVM, we should synchronize the registers before we get dump
1457     * info or physmap info.
1458     */
1459    cpu_synchronize_all_states();
1460    nr_cpus = 0;
1461    CPU_FOREACH(cpu) {
1462        nr_cpus++;
1463    }
1464
1465    s->fd = fd;
1466    s->has_filter = has_filter;
1467    s->begin = begin;
1468    s->length = length;
1469
1470    memory_mapping_list_init(&s->list);
1471
1472    guest_phys_blocks_init(&s->guest_phys_blocks);
1473    guest_phys_blocks_append(&s->guest_phys_blocks);
1474
1475    s->start = get_start_block(s);
1476    if (s->start == -1) {
1477        error_set(errp, QERR_INVALID_PARAMETER, "begin");
1478        goto cleanup;
1479    }
1480
1481    /* get dump info: endian, class and architecture.
1482     * If the target architecture is not supported, cpu_get_dump_info() will
1483     * return -1.
1484     */
1485    ret = cpu_get_dump_info(&s->dump_info, &s->guest_phys_blocks);
1486    if (ret < 0) {
1487        error_set(errp, QERR_UNSUPPORTED);
1488        goto cleanup;
1489    }
1490
1491    s->note_size = cpu_get_note_size(s->dump_info.d_class,
1492                                     s->dump_info.d_machine, nr_cpus);
1493    if (s->note_size < 0) {
1494        error_set(errp, QERR_UNSUPPORTED);
1495        goto cleanup;
1496    }
1497
1498    /* get memory mapping */
1499    if (paging) {
1500        qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, &err);
1501        if (err != NULL) {
1502            error_propagate(errp, err);
1503            goto cleanup;
1504        }
1505    } else {
1506        qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
1507    }
1508
1509    s->nr_cpus = nr_cpus;
1510
1511    get_max_mapnr(s);
1512
1513    uint64_t tmp;
1514    tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), TARGET_PAGE_SIZE);
1515    s->len_dump_bitmap = tmp * TARGET_PAGE_SIZE;
1516
1517    /* init for kdump-compressed format */
1518    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1519        switch (format) {
1520        case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
1521            s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
1522            break;
1523
1524        case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
1525#ifdef CONFIG_LZO
1526            if (lzo_init() != LZO_E_OK) {
1527                error_setg(errp, "failed to initialize the LZO library");
1528                goto cleanup;
1529            }
1530#endif
1531            s->flag_compress = DUMP_DH_COMPRESSED_LZO;
1532            break;
1533
1534        case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
1535            s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
1536            break;
1537
1538        default:
1539            s->flag_compress = 0;
1540        }
1541
1542        return;
1543    }
1544
1545    if (s->has_filter) {
1546        memory_mapping_filter(&s->list, s->begin, s->length);
1547    }
1548
1549    /*
1550     * calculate phdr_num
1551     *
1552     * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
1553     */
1554    s->phdr_num = 1; /* PT_NOTE */
1555    if (s->list.num < UINT16_MAX - 2) {
1556        s->phdr_num += s->list.num;
1557        s->have_section = false;
1558    } else {
1559        s->have_section = true;
1560        s->phdr_num = PN_XNUM;
1561        s->sh_info = 1; /* PT_NOTE */
1562
1563        /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
1564        if (s->list.num <= UINT32_MAX - 1) {
1565            s->sh_info += s->list.num;
1566        } else {
1567            s->sh_info = UINT32_MAX;
1568        }
1569    }
1570
1571    if (s->dump_info.d_class == ELFCLASS64) {
1572        if (s->have_section) {
1573            s->memory_offset = sizeof(Elf64_Ehdr) +
1574                               sizeof(Elf64_Phdr) * s->sh_info +
1575                               sizeof(Elf64_Shdr) + s->note_size;
1576        } else {
1577            s->memory_offset = sizeof(Elf64_Ehdr) +
1578                               sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;
1579        }
1580    } else {
1581        if (s->have_section) {
1582            s->memory_offset = sizeof(Elf32_Ehdr) +
1583                               sizeof(Elf32_Phdr) * s->sh_info +
1584                               sizeof(Elf32_Shdr) + s->note_size;
1585        } else {
1586            s->memory_offset = sizeof(Elf32_Ehdr) +
1587                               sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;
1588        }
1589    }
1590
1591    return;
1592
1593cleanup:
1594    dump_cleanup(s);
1595}
1596
1597void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
1598                           int64_t begin, bool has_length,
1599                           int64_t length, bool has_format,
1600                           DumpGuestMemoryFormat format, Error **errp)
1601{
1602    const char *p;
1603    int fd = -1;
1604    DumpState *s;
1605    Error *local_err = NULL;
1606
1607    /*
1608     * kdump-compressed format need the whole memory dumped, so paging or
1609     * filter is not supported here.
1610     */
1611    if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
1612        (paging || has_begin || has_length)) {
1613        error_setg(errp, "kdump-compressed format doesn't support paging or "
1614                         "filter");
1615        return;
1616    }
1617    if (has_begin && !has_length) {
1618        error_set(errp, QERR_MISSING_PARAMETER, "length");
1619        return;
1620    }
1621    if (!has_begin && has_length) {
1622        error_set(errp, QERR_MISSING_PARAMETER, "begin");
1623        return;
1624    }
1625
1626    /* check whether lzo/snappy is supported */
1627#ifndef CONFIG_LZO
1628    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
1629        error_setg(errp, "kdump-lzo is not available now");
1630        return;
1631    }
1632#endif
1633
1634#ifndef CONFIG_SNAPPY
1635    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
1636        error_setg(errp, "kdump-snappy is not available now");
1637        return;
1638    }
1639#endif
1640
1641#if !defined(WIN32)
1642    if (strstart(file, "fd:", &p)) {
1643        fd = monitor_get_fd(cur_mon, p, errp);
1644        if (fd == -1) {
1645            return;
1646        }
1647    }
1648#endif
1649
1650    if  (strstart(file, "file:", &p)) {
1651        fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
1652        if (fd < 0) {
1653            error_setg_file_open(errp, errno, p);
1654            return;
1655        }
1656    }
1657
1658    if (fd == -1) {
1659        error_set(errp, QERR_INVALID_PARAMETER, "protocol");
1660        return;
1661    }
1662
1663    s = g_malloc0(sizeof(DumpState));
1664
1665    dump_init(s, fd, has_format, format, paging, has_begin,
1666              begin, length, &local_err);
1667    if (local_err) {
1668        g_free(s);
1669        error_propagate(errp, local_err);
1670        return;
1671    }
1672
1673    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
1674        create_kdump_vmcore(s, errp);
1675    } else {
1676        create_vmcore(s, errp);
1677    }
1678
1679    g_free(s);
1680}
1681
1682DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
1683{
1684    DumpGuestMemoryFormatList *item;
1685    DumpGuestMemoryCapability *cap =
1686                                  g_malloc0(sizeof(DumpGuestMemoryCapability));
1687
1688    /* elf is always available */
1689    item = g_malloc0(sizeof(DumpGuestMemoryFormatList));
1690    cap->formats = item;
1691    item->value = DUMP_GUEST_MEMORY_FORMAT_ELF;
1692
1693    /* kdump-zlib is always available */
1694    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
1695    item = item->next;
1696    item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
1697
1698    /* add new item if kdump-lzo is available */
1699#ifdef CONFIG_LZO
1700    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
1701    item = item->next;
1702    item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
1703#endif
1704
1705    /* add new item if kdump-snappy is available */
1706#ifdef CONFIG_SNAPPY
1707    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
1708    item = item->next;
1709    item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
1710#endif
1711
1712    return cap;
1713}
1714