qemu

dump.c (66675B)

---

 /*
  * QEMU dump
  *
  * Copyright Fujitsu, Corp. 2011, 2012
  *
  * Authors:
  *     Wen Congyang <wency@cn.fujitsu.com>
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  * See the COPYING file in the top-level directory.
  *
  */
 
 #include "qemu/osdep.h"
 #include "qemu/cutils.h"
 #include "elf.h"
 #include "exec/hwaddr.h"
 #include "monitor/monitor.h"
 #include "sysemu/kvm.h"
 #include "sysemu/dump.h"
 #include "sysemu/memory_mapping.h"
 #include "sysemu/runstate.h"
 #include "sysemu/cpus.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-dump.h"
 #include "qapi/qapi-events-dump.h"
 #include "qapi/qmp/qerror.h"
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "hw/misc/vmcoreinfo.h"
 #include "migration/blocker.h"
 
 #ifdef TARGET_X86_64
 #include "win_dump.h"
 #endif
 
 #include <zlib.h>
 #ifdef CONFIG_LZO
 #include <lzo/lzo1x.h>
 #endif
 #ifdef CONFIG_SNAPPY
 #include <snappy-c.h>
 #endif
 #ifndef ELF_MACHINE_UNAME
 #define ELF_MACHINE_UNAME "Unknown"
 #endif
 
 #define MAX_GUEST_NOTE_SIZE (1 << 20) /* 1MB should be enough */
 
 static Error *dump_migration_blocker;
 
 #define ELF_NOTE_SIZE(hdr_size, name_size, desc_size)   \
     ((DIV_ROUND_UP((hdr_size), 4) +                     \
       DIV_ROUND_UP((name_size), 4) +                    \
       DIV_ROUND_UP((desc_size), 4)) * 4)
 
 static inline bool dump_is_64bit(DumpState *s)
 {
     return s->dump_info.d_class == ELFCLASS64;
 }
 
 static inline bool dump_has_filter(DumpState *s)
 {
     return s->filter_area_length > 0;
 }
 
 uint16_t cpu_to_dump16(DumpState *s, uint16_t val)
 {
     if (s->dump_info.d_endian == ELFDATA2LSB) {
         val = cpu_to_le16(val);
     } else {
         val = cpu_to_be16(val);
     }
 
     return val;
 }
 
 uint32_t cpu_to_dump32(DumpState *s, uint32_t val)
 {
     if (s->dump_info.d_endian == ELFDATA2LSB) {
         val = cpu_to_le32(val);
     } else {
         val = cpu_to_be32(val);
     }
 
     return val;
 }
 
 uint64_t cpu_to_dump64(DumpState *s, uint64_t val)
 {
     if (s->dump_info.d_endian == ELFDATA2LSB) {
         val = cpu_to_le64(val);
     } else {
         val = cpu_to_be64(val);
     }
 
     return val;
 }
 
 static int dump_cleanup(DumpState *s)
 {
     guest_phys_blocks_free(&s->guest_phys_blocks);
     memory_mapping_list_free(&s->list);
     close(s->fd);
     g_free(s->guest_note);
     g_array_unref(s->string_table_buf);
     s->guest_note = NULL;
     if (s->resume) {
         if (s->detached) {
             qemu_mutex_lock_iothread();
         }
         vm_start();
         if (s->detached) {
             qemu_mutex_unlock_iothread();
         }
     }
     migrate_del_blocker(dump_migration_blocker);
 
     return 0;
 }
 
 static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
 {
     DumpState *s = opaque;
     size_t written_size;
 
     written_size = qemu_write_full(s->fd, buf, size);
     if (written_size != size) {
         return -errno;
     }
 
     return 0;
 }
 
 static void prepare_elf64_header(DumpState *s, Elf64_Ehdr *elf_header)
 {
     /*
      * phnum in the elf header is 16 bit, if we have more segments we
      * set phnum to PN_XNUM and write the real number of segments to a
      * special section.
      */
     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
 
     memset(elf_header, 0, sizeof(Elf64_Ehdr));
     memcpy(elf_header, ELFMAG, SELFMAG);
     elf_header->e_ident[EI_CLASS] = ELFCLASS64;
     elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
     elf_header->e_ident[EI_VERSION] = EV_CURRENT;
     elf_header->e_type = cpu_to_dump16(s, ET_CORE);
     elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
     elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
     elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
     elf_header->e_phoff = cpu_to_dump64(s, s->phdr_offset);
     elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
     elf_header->e_phnum = cpu_to_dump16(s, phnum);
     elf_header->e_shoff = cpu_to_dump64(s, s->shdr_offset);
     elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
     elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
     elf_header->e_shstrndx = cpu_to_dump16(s, s->shdr_num - 1);
 }
 
 static void prepare_elf32_header(DumpState *s, Elf32_Ehdr *elf_header)
 {
     /*
      * phnum in the elf header is 16 bit, if we have more segments we
      * set phnum to PN_XNUM and write the real number of segments to a
      * special section.
      */
     uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
 
     memset(elf_header, 0, sizeof(Elf32_Ehdr));
     memcpy(elf_header, ELFMAG, SELFMAG);
     elf_header->e_ident[EI_CLASS] = ELFCLASS32;
     elf_header->e_ident[EI_DATA] = s->dump_info.d_endian;
     elf_header->e_ident[EI_VERSION] = EV_CURRENT;
     elf_header->e_type = cpu_to_dump16(s, ET_CORE);
     elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
     elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
     elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
     elf_header->e_phoff = cpu_to_dump32(s, s->phdr_offset);
     elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
     elf_header->e_phnum = cpu_to_dump16(s, phnum);
     elf_header->e_shoff = cpu_to_dump32(s, s->shdr_offset);
     elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
     elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
     elf_header->e_shstrndx = cpu_to_dump16(s, s->shdr_num - 1);
 }
 
 static void write_elf_header(DumpState *s, Error **errp)
 {
     Elf32_Ehdr elf32_header;
     Elf64_Ehdr elf64_header;
     size_t header_size;
     void *header_ptr;
     int ret;
 
     /* The NULL header and the shstrtab are always defined */
     assert(s->shdr_num >= 2);
     if (dump_is_64bit(s)) {
         prepare_elf64_header(s, &elf64_header);
         header_size = sizeof(elf64_header);
         header_ptr = &elf64_header;
     } else {
         prepare_elf32_header(s, &elf32_header);
         header_size = sizeof(elf32_header);
         header_ptr = &elf32_header;
     }
 
     ret = fd_write_vmcore(header_ptr, header_size, s);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "dump: failed to write elf header");
     }
 }
 
 static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
                              int phdr_index, hwaddr offset,
                              hwaddr filesz, Error **errp)
 {
     Elf64_Phdr phdr;
     int ret;
 
     memset(&phdr, 0, sizeof(Elf64_Phdr));
     phdr.p_type = cpu_to_dump32(s, PT_LOAD);
     phdr.p_offset = cpu_to_dump64(s, offset);
     phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
     phdr.p_filesz = cpu_to_dump64(s, filesz);
     phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
     phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
 
     assert(memory_mapping->length >= filesz);
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
         error_setg_errno(errp, -ret,
                          "dump: failed to write program header table");
     }
 }
 
 static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
                              int phdr_index, hwaddr offset,
                              hwaddr filesz, Error **errp)
 {
     Elf32_Phdr phdr;
     int ret;
 
     memset(&phdr, 0, sizeof(Elf32_Phdr));
     phdr.p_type = cpu_to_dump32(s, PT_LOAD);
     phdr.p_offset = cpu_to_dump32(s, offset);
     phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
     phdr.p_filesz = cpu_to_dump32(s, filesz);
     phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
     phdr.p_vaddr =
         cpu_to_dump32(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
 
     assert(memory_mapping->length >= filesz);
 
     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
         error_setg_errno(errp, -ret,
                          "dump: failed to write program header table");
     }
 }
 
 static void prepare_elf64_phdr_note(DumpState *s, Elf64_Phdr *phdr)
 {
     memset(phdr, 0, sizeof(*phdr));
     phdr->p_type = cpu_to_dump32(s, PT_NOTE);
     phdr->p_offset = cpu_to_dump64(s, s->note_offset);
     phdr->p_paddr = 0;
     phdr->p_filesz = cpu_to_dump64(s, s->note_size);
     phdr->p_memsz = cpu_to_dump64(s, s->note_size);
     phdr->p_vaddr = 0;
 }
 
 static inline int cpu_index(CPUState *cpu)
 {
     return cpu->cpu_index + 1;
 }
 
 static void write_guest_note(WriteCoreDumpFunction f, DumpState *s,
                              Error **errp)
 {
     int ret;
 
     if (s->guest_note) {
         ret = f(s->guest_note, s->guest_note_size, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to write guest note");
         }
     }
 }
 
 static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
                               Error **errp)
 {
     CPUState *cpu;
     int ret;
     int id;
 
     CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf64_note(f, cpu, id, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to write elf notes");
             return;
         }
     }
 
     CPU_FOREACH(cpu) {
         ret = cpu_write_elf64_qemunote(f, cpu, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to write CPU status");
             return;
         }
     }
 
     write_guest_note(f, s, errp);
 }
 
 static void prepare_elf32_phdr_note(DumpState *s, Elf32_Phdr *phdr)
 {
     memset(phdr, 0, sizeof(*phdr));
     phdr->p_type = cpu_to_dump32(s, PT_NOTE);
     phdr->p_offset = cpu_to_dump32(s, s->note_offset);
     phdr->p_paddr = 0;
     phdr->p_filesz = cpu_to_dump32(s, s->note_size);
     phdr->p_memsz = cpu_to_dump32(s, s->note_size);
     phdr->p_vaddr = 0;
 }
 
 static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
                               Error **errp)
 {
     CPUState *cpu;
     int ret;
     int id;
 
     CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf32_note(f, cpu, id, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to write elf notes");
             return;
         }
     }
 
     CPU_FOREACH(cpu) {
         ret = cpu_write_elf32_qemunote(f, cpu, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to write CPU status");
             return;
         }
     }
 
     write_guest_note(f, s, errp);
 }
 
 static void write_elf_phdr_note(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     Elf32_Phdr phdr32;
     Elf64_Phdr phdr64;
     void *phdr;
     size_t size;
     int ret;
 
     if (dump_is_64bit(s)) {
         prepare_elf64_phdr_note(s, &phdr64);
         size = sizeof(phdr64);
         phdr = &phdr64;
     } else {
         prepare_elf32_phdr_note(s, &phdr32);
         size = sizeof(phdr32);
         phdr = &phdr32;
     }
 
     ret = fd_write_vmcore(phdr, size, s);
     if (ret < 0) {
         error_setg_errno(errp, -ret,
                          "dump: failed to write program header table");
     }
 }
 
 static void prepare_elf_section_hdr_zero(DumpState *s)
 {
     if (dump_is_64bit(s)) {
         Elf64_Shdr *shdr64 = s->elf_section_hdrs;
 
         shdr64->sh_info = cpu_to_dump32(s, s->phdr_num);
     } else {
         Elf32_Shdr *shdr32 = s->elf_section_hdrs;
 
         shdr32->sh_info = cpu_to_dump32(s, s->phdr_num);
     }
 }
 
 static void prepare_elf_section_hdr_string(DumpState *s, void *buff)
 {
     uint64_t index = s->string_table_buf->len;
     const char strtab[] = ".shstrtab";
     Elf32_Shdr shdr32 = {};
     Elf64_Shdr shdr64 = {};
     int shdr_size;
     void *shdr;
 
     g_array_append_vals(s->string_table_buf, strtab, sizeof(strtab));
     if (dump_is_64bit(s)) {
         shdr_size = sizeof(Elf64_Shdr);
         shdr64.sh_type = SHT_STRTAB;
         shdr64.sh_offset = s->section_offset + s->elf_section_data_size;
         shdr64.sh_name = index;
         shdr64.sh_size = s->string_table_buf->len;
         shdr = &shdr64;
     } else {
         shdr_size = sizeof(Elf32_Shdr);
         shdr32.sh_type = SHT_STRTAB;
         shdr32.sh_offset = s->section_offset + s->elf_section_data_size;
         shdr32.sh_name = index;
         shdr32.sh_size = s->string_table_buf->len;
         shdr = &shdr32;
     }
     memcpy(buff, shdr, shdr_size);
 }
 
 static bool prepare_elf_section_hdrs(DumpState *s, Error **errp)
 {
     size_t len, sizeof_shdr;
     void *buff_hdr;
 
     /*
      * Section ordering:
      * - HDR zero
      * - Arch section hdrs
      * - String table hdr
      */
     sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
     len = sizeof_shdr * s->shdr_num;
     s->elf_section_hdrs = g_malloc0(len);
     buff_hdr = s->elf_section_hdrs;
 
     /*
      * The first section header is ALWAYS a special initial section
      * header.
      *
      * The header should be 0 with one exception being that if
      * phdr_num is PN_XNUM then the sh_info field contains the real
      * number of segment entries.
      *
      * As we zero allocate the buffer we will only need to modify
      * sh_info for the PN_XNUM case.
      */
     if (s->phdr_num >= PN_XNUM) {
         prepare_elf_section_hdr_zero(s);
     }
     buff_hdr += sizeof_shdr;
 
     /* Add architecture defined section headers */
     if (s->dump_info.arch_sections_write_hdr_fn
         && s->shdr_num > 2) {
         buff_hdr += s->dump_info.arch_sections_write_hdr_fn(s, buff_hdr);
 
         if (s->shdr_num >= SHN_LORESERVE) {
             error_setg_errno(errp, EINVAL,
                              "dump: too many architecture defined sections");
             return false;
         }
     }
 
     /*
      * String table is the last section since strings are added via
      * arch_sections_write_hdr().
      */
     prepare_elf_section_hdr_string(s, buff_hdr);
     return true;
 }
 
 static void write_elf_section_headers(DumpState *s, Error **errp)
 {
     size_t sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
     int ret;
 
     if (!prepare_elf_section_hdrs(s, errp)) {
         return;
     }
 
     ret = fd_write_vmcore(s->elf_section_hdrs, s->shdr_num * sizeof_shdr, s);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "dump: failed to write section headers");
     }
 
     g_free(s->elf_section_hdrs);
 }
 
 static void write_elf_sections(DumpState *s, Error **errp)
 {
     int ret;
 
     if (s->elf_section_data_size) {
         /* Write architecture section data */
         ret = fd_write_vmcore(s->elf_section_data,
                               s->elf_section_data_size, s);
         if (ret < 0) {
             error_setg_errno(errp, -ret,
                              "dump: failed to write architecture section data");
             return;
         }
     }
 
     /* Write string table */
     ret = fd_write_vmcore(s->string_table_buf->data,
                           s->string_table_buf->len, s);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "dump: failed to write string table data");
     }
 }
 
 static void write_data(DumpState *s, void *buf, int length, Error **errp)
 {
     int ret;
 
     ret = fd_write_vmcore(buf, length, s);
     if (ret < 0) {
         error_setg_errno(errp, -ret, "dump: failed to save memory");
     } else {
         s->written_size += length;
     }
 }
 
 /* write the memory to vmcore. 1 page per I/O. */
 static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
                          int64_t size, Error **errp)
 {
     ERRP_GUARD();
     int64_t i;
 
     for (i = 0; i < size / s->dump_info.page_size; i++) {
         write_data(s, block->host_addr + start + i * s->dump_info.page_size,
                    s->dump_info.page_size, errp);
         if (*errp) {
             return;
         }
     }
 
     if ((size % s->dump_info.page_size) != 0) {
         write_data(s, block->host_addr + start + i * s->dump_info.page_size,
                    size % s->dump_info.page_size, errp);
         if (*errp) {
             return;
         }
     }
 }
 
 /* get the memory's offset and size in the vmcore */
 static void get_offset_range(hwaddr phys_addr,
                              ram_addr_t mapping_length,
                              DumpState *s,
                              hwaddr *p_offset,
                              hwaddr *p_filesz)
 {
     GuestPhysBlock *block;
     hwaddr offset = s->memory_offset;
     int64_t size_in_block, start;
 
     /* When the memory is not stored into vmcore, offset will be -1 */
     *p_offset = -1;
     *p_filesz = 0;
 
     if (dump_has_filter(s)) {
         if (phys_addr < s->filter_area_begin ||
             phys_addr >= s->filter_area_begin + s->filter_area_length) {
             return;
         }
     }
 
     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
         if (dump_has_filter(s)) {
             if (block->target_start >= s->filter_area_begin + s->filter_area_length ||
                 block->target_end <= s->filter_area_begin) {
                 /* This block is out of the range */
                 continue;
             }
 
             if (s->filter_area_begin <= block->target_start) {
                 start = block->target_start;
             } else {
                 start = s->filter_area_begin;
             }
 
             size_in_block = block->target_end - start;
             if (s->filter_area_begin + s->filter_area_length < block->target_end) {
                 size_in_block -= block->target_end - (s->filter_area_begin + s->filter_area_length);
             }
         } else {
             start = block->target_start;
             size_in_block = block->target_end - block->target_start;
         }
 
         if (phys_addr >= start && phys_addr < start + size_in_block) {
             *p_offset = phys_addr - start + offset;
 
             /* The offset range mapped from the vmcore file must not spill over
              * the GuestPhysBlock, clamp it. The rest of the mapping will be
              * zero-filled in memory at load time; see
              * <http://refspecs.linuxbase.org/elf/gabi4+/ch5.pheader.html>.
              */
             *p_filesz = phys_addr + mapping_length <= start + size_in_block ?
                         mapping_length :
                         size_in_block - (phys_addr - start);
             return;
         }
 
         offset += size_in_block;
     }
 }
 
 static void write_elf_phdr_loads(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     hwaddr offset, filesz;
     MemoryMapping *memory_mapping;
     uint32_t phdr_index = 1;
 
     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
         get_offset_range(memory_mapping->phys_addr,
                          memory_mapping->length,
                          s, &offset, &filesz);
         if (dump_is_64bit(s)) {
             write_elf64_load(s, memory_mapping, phdr_index++, offset,
                              filesz, errp);
         } else {
             write_elf32_load(s, memory_mapping, phdr_index++, offset,
                              filesz, errp);
         }
 
         if (*errp) {
             return;
         }
 
         if (phdr_index >= s->phdr_num) {
             break;
         }
     }
 }
 
 static void write_elf_notes(DumpState *s, Error **errp)
 {
     if (dump_is_64bit(s)) {
         write_elf64_notes(fd_write_vmcore, s, errp);
     } else {
         write_elf32_notes(fd_write_vmcore, s, errp);
     }
 }
 
 /* write elf header, PT_NOTE and elf note to vmcore. */
 static void dump_begin(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
 
     /*
      * the vmcore's format is:
      *   --------------
      *   |  elf header |
      *   --------------
      *   |  sctn_hdr   |
      *   --------------
      *   |  PT_NOTE    |
      *   --------------
      *   |  PT_LOAD    |
      *   --------------
      *   |  ......     |
      *   --------------
      *   |  PT_LOAD    |
      *   --------------
      *   |  elf note   |
      *   --------------
      *   |  memory     |
      *   --------------
      *
      * we only know where the memory is saved after we write elf note into
      * vmcore.
      */
 
     /* write elf header to vmcore */
     write_elf_header(s, errp);
     if (*errp) {
         return;
     }
 
     /* write section headers to vmcore */
     write_elf_section_headers(s, errp);
     if (*errp) {
         return;
     }
 
     /* write PT_NOTE to vmcore */
     write_elf_phdr_note(s, errp);
     if (*errp) {
         return;
     }
 
     /* write all PT_LOADs to vmcore */
     write_elf_phdr_loads(s, errp);
     if (*errp) {
         return;
     }
 
     /* write notes to vmcore */
     write_elf_notes(s, errp);
 }
 
 int64_t dump_filtered_memblock_size(GuestPhysBlock *block,
                                     int64_t filter_area_start,
                                     int64_t filter_area_length)
 {
     int64_t size, left, right;
 
     /* No filter, return full size */
     if (!filter_area_length) {
         return block->target_end - block->target_start;
     }
 
     /* calculate the overlapped region. */
     left = MAX(filter_area_start, block->target_start);
     right = MIN(filter_area_start + filter_area_length, block->target_end);
     size = right - left;
     size = size > 0 ? size : 0;
 
     return size;
 }
 
 int64_t dump_filtered_memblock_start(GuestPhysBlock *block,
                                      int64_t filter_area_start,
                                      int64_t filter_area_length)
 {
     if (filter_area_length) {
         /* return -1 if the block is not within filter area */
         if (block->target_start >= filter_area_start + filter_area_length ||
             block->target_end <= filter_area_start) {
             return -1;
         }
 
         if (filter_area_start > block->target_start) {
             return filter_area_start - block->target_start;
         }
     }
 
     return 0;
 }
 
 /* write all memory to vmcore */
 static void dump_iterate(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     GuestPhysBlock *block;
     int64_t memblock_size, memblock_start;
 
     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
         memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin, s->filter_area_length);
         if (memblock_start == -1) {
             continue;
         }
 
         memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin, s->filter_area_length);
 
         /* Write the memory to file */
         write_memory(s, block, memblock_start, memblock_size, errp);
         if (*errp) {
             return;
         }
     }
 }
 
 static void dump_end(DumpState *s, Error **errp)
 {
     int rc;
     ERRP_GUARD();
 
     if (s->elf_section_data_size) {
         s->elf_section_data = g_malloc0(s->elf_section_data_size);
     }
 
     /* Adds the architecture defined section data to s->elf_section_data  */
     if (s->dump_info.arch_sections_write_fn &&
         s->elf_section_data_size) {
         rc = s->dump_info.arch_sections_write_fn(s, s->elf_section_data);
         if (rc) {
             error_setg_errno(errp, rc,
                              "dump: failed to get arch section data");
             g_free(s->elf_section_data);
             return;
         }
     }
 
     /* write sections to vmcore */
     write_elf_sections(s, errp);
 }
 
 static void create_vmcore(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
 
     dump_begin(s, errp);
     if (*errp) {
         return;
     }
 
     /* Iterate over memory and dump it to file */
     dump_iterate(s, errp);
     if (*errp) {
         return;
     }
 
     /* Write the section data */
     dump_end(s, errp);
 }
 
 static int write_start_flat_header(int fd)
 {
     MakedumpfileHeader *mh;
     int ret = 0;
 
     QEMU_BUILD_BUG_ON(sizeof *mh > MAX_SIZE_MDF_HEADER);
     mh = g_malloc0(MAX_SIZE_MDF_HEADER);
 
     memcpy(mh->signature, MAKEDUMPFILE_SIGNATURE,
            MIN(sizeof mh->signature, sizeof MAKEDUMPFILE_SIGNATURE));
 
     mh->type = cpu_to_be64(TYPE_FLAT_HEADER);
     mh->version = cpu_to_be64(VERSION_FLAT_HEADER);
 
     size_t written_size;
     written_size = qemu_write_full(fd, mh, MAX_SIZE_MDF_HEADER);
     if (written_size != MAX_SIZE_MDF_HEADER) {
         ret = -1;
     }
 
     g_free(mh);
     return ret;
 }
 
 static int write_end_flat_header(int fd)
 {
     MakedumpfileDataHeader mdh;
 
     mdh.offset = END_FLAG_FLAT_HEADER;
     mdh.buf_size = END_FLAG_FLAT_HEADER;
 
     size_t written_size;
     written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
     if (written_size != sizeof(mdh)) {
         return -1;
     }
 
     return 0;
 }
 
 static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
 {
     size_t written_size;
     MakedumpfileDataHeader mdh;
 
     mdh.offset = cpu_to_be64(offset);
     mdh.buf_size = cpu_to_be64(size);
 
     written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
     if (written_size != sizeof(mdh)) {
         return -1;
     }
 
     written_size = qemu_write_full(fd, buf, size);
     if (written_size != size) {
         return -1;
     }
 
     return 0;
 }
 
 static int buf_write_note(const void *buf, size_t size, void *opaque)
 {
     DumpState *s = opaque;
 
     /* note_buf is not enough */
     if (s->note_buf_offset + size > s->note_size) {
         return -1;
     }
 
     memcpy(s->note_buf + s->note_buf_offset, buf, size);
 
     s->note_buf_offset += size;
 
     return 0;
 }
 
 /*
  * This function retrieves various sizes from an elf header.
  *
  * @note has to be a valid ELF note. The return sizes are unmodified
  * (not padded or rounded up to be multiple of 4).
  */
 static void get_note_sizes(DumpState *s, const void *note,
                            uint64_t *note_head_size,
                            uint64_t *name_size,
                            uint64_t *desc_size)
 {
     uint64_t note_head_sz;
     uint64_t name_sz;
     uint64_t desc_sz;
 
     if (dump_is_64bit(s)) {
         const Elf64_Nhdr *hdr = note;
         note_head_sz = sizeof(Elf64_Nhdr);
         name_sz = tswap64(hdr->n_namesz);
         desc_sz = tswap64(hdr->n_descsz);
     } else {
         const Elf32_Nhdr *hdr = note;
         note_head_sz = sizeof(Elf32_Nhdr);
         name_sz = tswap32(hdr->n_namesz);
         desc_sz = tswap32(hdr->n_descsz);
     }
 
     if (note_head_size) {
         *note_head_size = note_head_sz;
     }
     if (name_size) {
         *name_size = name_sz;
     }
     if (desc_size) {
         *desc_size = desc_sz;
     }
 }
 
 static bool note_name_equal(DumpState *s,
                             const uint8_t *note, const char *name)
 {
     int len = strlen(name) + 1;
     uint64_t head_size, name_size;
 
     get_note_sizes(s, note, &head_size, &name_size, NULL);
     head_size = ROUND_UP(head_size, 4);
 
     return name_size == len && memcmp(note + head_size, name, len) == 0;
 }
 
 /* write common header, sub header and elf note to vmcore */
 static void create_header32(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     DiskDumpHeader32 *dh = NULL;
     KdumpSubHeader32 *kh = NULL;
     size_t size;
     uint32_t block_size;
     uint32_t sub_hdr_size;
     uint32_t bitmap_blocks;
     uint32_t status = 0;
     uint64_t offset_note;
 
     /* write common header, the version of kdump-compressed format is 6th */
     size = sizeof(DiskDumpHeader32);
     dh = g_malloc0(size);
 
     memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
     dh->header_version = cpu_to_dump32(s, 6);
     block_size = s->dump_info.page_size;
     dh->block_size = cpu_to_dump32(s, block_size);
     sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
     sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
     dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
     /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
     dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
     dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
     dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
     strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
 
     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
         status |= DUMP_DH_COMPRESSED_ZLIB;
     }
 #ifdef CONFIG_LZO
     if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
         status |= DUMP_DH_COMPRESSED_LZO;
     }
 #endif
 #ifdef CONFIG_SNAPPY
     if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
         status |= DUMP_DH_COMPRESSED_SNAPPY;
     }
 #endif
     dh->status = cpu_to_dump32(s, status);
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
         error_setg(errp, "dump: failed to write disk dump header");
         goto out;
     }
 
     /* write sub header */
     size = sizeof(KdumpSubHeader32);
     kh = g_malloc0(size);
 
     /* 64bit max_mapnr_64 */
     kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
     kh->phys_base = cpu_to_dump32(s, s->dump_info.phys_base);
     kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
 
     offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
     if (s->guest_note &&
         note_name_equal(s, s->guest_note, "VMCOREINFO")) {
         uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
 
         get_note_sizes(s, s->guest_note,
                        &hsize, &name_size, &size_vmcoreinfo_desc);
         offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
             (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
         kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
         kh->size_vmcoreinfo = cpu_to_dump32(s, size_vmcoreinfo_desc);
     }
 
     kh->offset_note = cpu_to_dump64(s, offset_note);
     kh->note_size = cpu_to_dump32(s, s->note_size);
 
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
         error_setg(errp, "dump: failed to write kdump sub header");
         goto out;
     }
 
     /* write note */
     s->note_buf = g_malloc0(s->note_size);
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
     write_elf32_notes(buf_write_note, s, errp);
     if (*errp) {
         goto out;
     }
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
         error_setg(errp, "dump: failed to write notes");
         goto out;
     }
 
     /* get offset of dump_bitmap */
     s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
                              block_size;
 
     /* get offset of page */
     s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
                      block_size;
 
 out:
     g_free(dh);
     g_free(kh);
     g_free(s->note_buf);
 }
 
 /* write common header, sub header and elf note to vmcore */
 static void create_header64(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     DiskDumpHeader64 *dh = NULL;
     KdumpSubHeader64 *kh = NULL;
     size_t size;
     uint32_t block_size;
     uint32_t sub_hdr_size;
     uint32_t bitmap_blocks;
     uint32_t status = 0;
     uint64_t offset_note;
 
     /* write common header, the version of kdump-compressed format is 6th */
     size = sizeof(DiskDumpHeader64);
     dh = g_malloc0(size);
 
     memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
     dh->header_version = cpu_to_dump32(s, 6);
     block_size = s->dump_info.page_size;
     dh->block_size = cpu_to_dump32(s, block_size);
     sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
     sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
     dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
     /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
     dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
     dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
     dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
     strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
 
     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
         status |= DUMP_DH_COMPRESSED_ZLIB;
     }
 #ifdef CONFIG_LZO
     if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
         status |= DUMP_DH_COMPRESSED_LZO;
     }
 #endif
 #ifdef CONFIG_SNAPPY
     if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
         status |= DUMP_DH_COMPRESSED_SNAPPY;
     }
 #endif
     dh->status = cpu_to_dump32(s, status);
 
     if (write_buffer(s->fd, 0, dh, size) < 0) {
         error_setg(errp, "dump: failed to write disk dump header");
         goto out;
     }
 
     /* write sub header */
     size = sizeof(KdumpSubHeader64);
     kh = g_malloc0(size);
 
     /* 64bit max_mapnr_64 */
     kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
     kh->phys_base = cpu_to_dump64(s, s->dump_info.phys_base);
     kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
 
     offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
     if (s->guest_note &&
         note_name_equal(s, s->guest_note, "VMCOREINFO")) {
         uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
 
         get_note_sizes(s, s->guest_note,
                        &hsize, &name_size, &size_vmcoreinfo_desc);
         offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
             (DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
         kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
         kh->size_vmcoreinfo = cpu_to_dump64(s, size_vmcoreinfo_desc);
     }
 
     kh->offset_note = cpu_to_dump64(s, offset_note);
     kh->note_size = cpu_to_dump64(s, s->note_size);
 
     if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
                      block_size, kh, size) < 0) {
         error_setg(errp, "dump: failed to write kdump sub header");
         goto out;
     }
 
     /* write note */
     s->note_buf = g_malloc0(s->note_size);
     s->note_buf_offset = 0;
 
     /* use s->note_buf to store notes temporarily */
     write_elf64_notes(buf_write_note, s, errp);
     if (*errp) {
         goto out;
     }
 
     if (write_buffer(s->fd, offset_note, s->note_buf,
                      s->note_size) < 0) {
         error_setg(errp, "dump: failed to write notes");
         goto out;
     }
 
     /* get offset of dump_bitmap */
     s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
                              block_size;
 
     /* get offset of page */
     s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
                      block_size;
 
 out:
     g_free(dh);
     g_free(kh);
     g_free(s->note_buf);
 }
 
 static void write_dump_header(DumpState *s, Error **errp)
 {
     if (dump_is_64bit(s)) {
         create_header64(s, errp);
     } else {
         create_header32(s, errp);
     }
 }
 
 static size_t dump_bitmap_get_bufsize(DumpState *s)
 {
     return s->dump_info.page_size;
 }
 
 /*
  * set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
  * rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
  * set_dump_bitmap will always leave the recently set bit un-sync. And setting
  * (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
  * vmcore, ie. synchronizing un-sync bit into vmcore.
  */
 static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
                            uint8_t *buf, DumpState *s)
 {
     off_t old_offset, new_offset;
     off_t offset_bitmap1, offset_bitmap2;
     uint32_t byte, bit;
     size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
     size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
 
     /* should not set the previous place */
     assert(last_pfn <= pfn);
 
     /*
      * if the bit needed to be set is not cached in buf, flush the data in buf
      * to vmcore firstly.
      * making new_offset be bigger than old_offset can also sync remained data
      * into vmcore.
      */
     old_offset = bitmap_bufsize * (last_pfn / bits_per_buf);
     new_offset = bitmap_bufsize * (pfn / bits_per_buf);
 
     while (old_offset < new_offset) {
         /* calculate the offset and write dump_bitmap */
         offset_bitmap1 = s->offset_dump_bitmap + old_offset;
         if (write_buffer(s->fd, offset_bitmap1, buf,
                          bitmap_bufsize) < 0) {
             return -1;
         }
 
         /* dump level 1 is chosen, so 1st and 2nd bitmap are same */
         offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
                          old_offset;
         if (write_buffer(s->fd, offset_bitmap2, buf,
                          bitmap_bufsize) < 0) {
             return -1;
         }
 
         memset(buf, 0, bitmap_bufsize);
         old_offset += bitmap_bufsize;
     }
 
     /* get the exact place of the bit in the buf, and set it */
     byte = (pfn % bits_per_buf) / CHAR_BIT;
     bit = (pfn % bits_per_buf) % CHAR_BIT;
     if (value) {
         buf[byte] |= 1u << bit;
     } else {
         buf[byte] &= ~(1u << bit);
     }
 
     return 0;
 }
 
 static uint64_t dump_paddr_to_pfn(DumpState *s, uint64_t addr)
 {
     int target_page_shift = ctz32(s->dump_info.page_size);
 
     return (addr >> target_page_shift) - ARCH_PFN_OFFSET;
 }
 
 static uint64_t dump_pfn_to_paddr(DumpState *s, uint64_t pfn)
 {
     int target_page_shift = ctz32(s->dump_info.page_size);
 
     return (pfn + ARCH_PFN_OFFSET) << target_page_shift;
 }
 
 /*
  * Return the page frame number and the page content in *bufptr. bufptr can be
  * NULL. If not NULL, *bufptr must contains a target page size of pre-allocated
  * memory. This is not necessarily the memory returned.
  */
 static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
                           uint8_t **bufptr, DumpState *s)
 {
     GuestPhysBlock *block = *blockptr;
     uint32_t page_size = s->dump_info.page_size;
     uint8_t *buf = NULL, *hbuf;
     hwaddr addr;
 
     /* block == NULL means the start of the iteration */
     if (!block) {
         block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
         *blockptr = block;
         addr = block->target_start;
         *pfnptr = dump_paddr_to_pfn(s, addr);
     } else {
         *pfnptr += 1;
         addr = dump_pfn_to_paddr(s, *pfnptr);
     }
     assert(block != NULL);
 
     while (1) {
         if (addr >= block->target_start && addr < block->target_end) {
             size_t n = MIN(block->target_end - addr, page_size - addr % page_size);
             hbuf = block->host_addr + (addr - block->target_start);
             if (!buf) {
                 if (n == page_size) {
                     /* this is a whole target page, go for it */
                     assert(addr % page_size == 0);
                     buf = hbuf;
                     break;
                 } else if (bufptr) {
                     assert(*bufptr);
                     buf = *bufptr;
                     memset(buf, 0, page_size);
                 } else {
                     return true;
                 }
             }
 
             memcpy(buf + addr % page_size, hbuf, n);
             addr += n;
             if (addr % page_size == 0) {
                 /* we filled up the page */
                 break;
             }
         } else {
             /* the next page is in the next block */
             *blockptr = block = QTAILQ_NEXT(block, next);
             if (!block) {
                 break;
             }
 
             addr = block->target_start;
             /* are we still in the same page? */
             if (dump_paddr_to_pfn(s, addr) != *pfnptr) {
                 if (buf) {
                     /* no, but we already filled something earlier, return it */
                     break;
                 } else {
                     /* else continue from there */
                     *pfnptr = dump_paddr_to_pfn(s, addr);
                 }
             }
         }
     }
 
     if (bufptr) {
         *bufptr = buf;
     }
 
     return buf != NULL;
 }
 
 static void write_dump_bitmap(DumpState *s, Error **errp)
 {
     int ret = 0;
     uint64_t last_pfn, pfn;
     void *dump_bitmap_buf;
     size_t num_dumpable;
     GuestPhysBlock *block_iter = NULL;
     size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
     size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
 
     /* dump_bitmap_buf is used to store dump_bitmap temporarily */
     dump_bitmap_buf = g_malloc0(bitmap_bufsize);
 
     num_dumpable = 0;
     last_pfn = 0;
 
     /*
      * exam memory page by page, and set the bit in dump_bitmap corresponded
      * to the existing page.
      */
     while (get_next_page(&block_iter, &pfn, NULL, s)) {
         ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to set dump_bitmap");
             goto out;
         }
 
         last_pfn = pfn;
         num_dumpable++;
     }
 
     /*
      * set_dump_bitmap will always leave the recently set bit un-sync. Here we
      * set the remaining bits from last_pfn to the end of the bitmap buffer to
      * 0. With those set, the un-sync bit will be synchronized into the vmcore.
      */
     if (num_dumpable > 0) {
         ret = set_dump_bitmap(last_pfn, last_pfn + bits_per_buf, false,
                               dump_bitmap_buf, s);
         if (ret < 0) {
             error_setg(errp, "dump: failed to sync dump_bitmap");
             goto out;
         }
     }
 
     /* number of dumpable pages that will be dumped later */
     s->num_dumpable = num_dumpable;
 
 out:
     g_free(dump_bitmap_buf);
 }
 
 static void prepare_data_cache(DataCache *data_cache, DumpState *s,
                                off_t offset)
 {
     data_cache->fd = s->fd;
     data_cache->data_size = 0;
     data_cache->buf_size = 4 * dump_bitmap_get_bufsize(s);
     data_cache->buf = g_malloc0(data_cache->buf_size);
     data_cache->offset = offset;
 }
 
 static int write_cache(DataCache *dc, const void *buf, size_t size,
                        bool flag_sync)
 {
     /*
      * dc->buf_size should not be less than size, otherwise dc will never be
      * enough
      */
     assert(size <= dc->buf_size);
 
     /*
      * if flag_sync is set, synchronize data in dc->buf into vmcore.
      * otherwise check if the space is enough for caching data in buf, if not,
      * write the data in dc->buf to dc->fd and reset dc->buf
      */
     if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
         (flag_sync && dc->data_size > 0)) {
         if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) {
             return -1;
         }
 
         dc->offset += dc->data_size;
         dc->data_size = 0;
     }
 
     if (!flag_sync) {
         memcpy(dc->buf + dc->data_size, buf, size);
         dc->data_size += size;
     }
 
     return 0;
 }
 
 static void free_data_cache(DataCache *data_cache)
 {
     g_free(data_cache->buf);
 }
 
 static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
 {
     switch (flag_compress) {
     case DUMP_DH_COMPRESSED_ZLIB:
         return compressBound(page_size);
 
     case DUMP_DH_COMPRESSED_LZO:
         /*
          * LZO will expand incompressible data by a little amount. Please check
          * the following URL to see the expansion calculation:
          * http://www.oberhumer.com/opensource/lzo/lzofaq.php
          */
         return page_size + page_size / 16 + 64 + 3;
 
 #ifdef CONFIG_SNAPPY
     case DUMP_DH_COMPRESSED_SNAPPY:
         return snappy_max_compressed_length(page_size);
 #endif
     }
     return 0;
 }
 
 static void write_dump_pages(DumpState *s, Error **errp)
 {
     int ret = 0;
     DataCache page_desc, page_data;
     size_t len_buf_out, size_out;
 #ifdef CONFIG_LZO
     lzo_bytep wrkmem = NULL;
 #endif
     uint8_t *buf_out = NULL;
     off_t offset_desc, offset_data;
     PageDescriptor pd, pd_zero;
     uint8_t *buf;
     GuestPhysBlock *block_iter = NULL;
     uint64_t pfn_iter;
     g_autofree uint8_t *page = NULL;
 
     /* get offset of page_desc and page_data in dump file */
     offset_desc = s->offset_page;
     offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
 
     prepare_data_cache(&page_desc, s, offset_desc);
     prepare_data_cache(&page_data, s, offset_data);
 
     /* prepare buffer to store compressed data */
     len_buf_out = get_len_buf_out(s->dump_info.page_size, s->flag_compress);
     assert(len_buf_out != 0);
 
 #ifdef CONFIG_LZO
     wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
 #endif
 
     buf_out = g_malloc(len_buf_out);
 
     /*
      * init zero page's page_desc and page_data, because every zero page
      * uses the same page_data
      */
     pd_zero.size = cpu_to_dump32(s, s->dump_info.page_size);
     pd_zero.flags = cpu_to_dump32(s, 0);
     pd_zero.offset = cpu_to_dump64(s, offset_data);
     pd_zero.page_flags = cpu_to_dump64(s, 0);
     buf = g_malloc0(s->dump_info.page_size);
     ret = write_cache(&page_data, buf, s->dump_info.page_size, false);
     g_free(buf);
     if (ret < 0) {
         error_setg(errp, "dump: failed to write page data (zero page)");
         goto out;
     }
 
     offset_data += s->dump_info.page_size;
     page = g_malloc(s->dump_info.page_size);
 
     /*
      * dump memory to vmcore page by page. zero page will all be resided in the
      * first page of page section
      */
     for (buf = page; get_next_page(&block_iter, &pfn_iter, &buf, s); buf = page) {
         /* check zero page */
         if (buffer_is_zero(buf, s->dump_info.page_size)) {
             ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
                               false);
             if (ret < 0) {
                 error_setg(errp, "dump: failed to write page desc");
                 goto out;
             }
         } else {
             /*
              * not zero page, then:
              * 1. compress the page
              * 2. write the compressed page into the cache of page_data
              * 3. get page desc of the compressed page and write it into the
              *    cache of page_desc
              *
              * only one compression format will be used here, for
              * s->flag_compress is set. But when compression fails to work,
              * we fall back to save in plaintext.
              */
              size_out = len_buf_out;
              if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
                     (compress2(buf_out, (uLongf *)&size_out, buf,
                                s->dump_info.page_size, Z_BEST_SPEED) == Z_OK) &&
                     (size_out < s->dump_info.page_size)) {
                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_ZLIB);
                 pd.size  = cpu_to_dump32(s, size_out);
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
                     error_setg(errp, "dump: failed to write page data");
                     goto out;
                 }
 #ifdef CONFIG_LZO
             } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
                     (lzo1x_1_compress(buf, s->dump_info.page_size, buf_out,
                     (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
                     (size_out < s->dump_info.page_size)) {
                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_LZO);
                 pd.size  = cpu_to_dump32(s, size_out);
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
                     error_setg(errp, "dump: failed to write page data");
                     goto out;
                 }
 #endif
 #ifdef CONFIG_SNAPPY
             } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
                     (snappy_compress((char *)buf, s->dump_info.page_size,
                     (char *)buf_out, &size_out) == SNAPPY_OK) &&
                     (size_out < s->dump_info.page_size)) {
                 pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_SNAPPY);
                 pd.size  = cpu_to_dump32(s, size_out);
 
                 ret = write_cache(&page_data, buf_out, size_out, false);
                 if (ret < 0) {
                     error_setg(errp, "dump: failed to write page data");
                     goto out;
                 }
 #endif
             } else {
                 /*
                  * fall back to save in plaintext, size_out should be
                  * assigned the target's page size
                  */
                 pd.flags = cpu_to_dump32(s, 0);
                 size_out = s->dump_info.page_size;
                 pd.size = cpu_to_dump32(s, size_out);
 
                 ret = write_cache(&page_data, buf,
                                   s->dump_info.page_size, false);
                 if (ret < 0) {
                     error_setg(errp, "dump: failed to write page data");
                     goto out;
                 }
             }
 
             /* get and write page desc here */
             pd.page_flags = cpu_to_dump64(s, 0);
             pd.offset = cpu_to_dump64(s, offset_data);
             offset_data += size_out;
 
             ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
             if (ret < 0) {
                 error_setg(errp, "dump: failed to write page desc");
                 goto out;
             }
         }
         s->written_size += s->dump_info.page_size;
     }
 
     ret = write_cache(&page_desc, NULL, 0, true);
     if (ret < 0) {
         error_setg(errp, "dump: failed to sync cache for page_desc");
         goto out;
     }
     ret = write_cache(&page_data, NULL, 0, true);
     if (ret < 0) {
         error_setg(errp, "dump: failed to sync cache for page_data");
         goto out;
     }
 
 out:
     free_data_cache(&page_desc);
     free_data_cache(&page_data);
 
 #ifdef CONFIG_LZO
     g_free(wrkmem);
 #endif
 
     g_free(buf_out);
 }
 
 static void create_kdump_vmcore(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     int ret;
 
     /*
      * the kdump-compressed format is:
      *                                               File offset
      *  +------------------------------------------+ 0x0
      *  |    main header (struct disk_dump_header) |
      *  |------------------------------------------+ block 1
      *  |    sub header (struct kdump_sub_header)  |
      *  |------------------------------------------+ block 2
      *  |            1st-dump_bitmap               |
      *  |------------------------------------------+ block 2 + X blocks
      *  |            2nd-dump_bitmap               | (aligned by block)
      *  |------------------------------------------+ block 2 + 2 * X blocks
      *  |  page desc for pfn 0 (struct page_desc)  | (aligned by block)
      *  |  page desc for pfn 1 (struct page_desc)  |
      *  |                    :                     |
      *  |------------------------------------------| (not aligned by block)
      *  |         page data (pfn 0)                |
      *  |         page data (pfn 1)                |
      *  |                    :                     |
      *  +------------------------------------------+
      */
 
     ret = write_start_flat_header(s->fd);
     if (ret < 0) {
         error_setg(errp, "dump: failed to write start flat header");
         return;
     }
 
     write_dump_header(s, errp);
     if (*errp) {
         return;
     }
 
     write_dump_bitmap(s, errp);
     if (*errp) {
         return;
     }
 
     write_dump_pages(s, errp);
     if (*errp) {
         return;
     }
 
     ret = write_end_flat_header(s->fd);
     if (ret < 0) {
         error_setg(errp, "dump: failed to write end flat header");
         return;
     }
 }
 
 static int validate_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
 
     if (!dump_has_filter(s)) {
         return 0;
     }
 
     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
         /* This block is out of the range */
         if (block->target_start >= s->filter_area_begin + s->filter_area_length ||
             block->target_end <= s->filter_area_begin) {
             continue;
         }
         return 0;
    }
 
     return -1;
 }
 
 static void get_max_mapnr(DumpState *s)
 {
     GuestPhysBlock *last_block;
 
     last_block = QTAILQ_LAST(&s->guest_phys_blocks.head);
     s->max_mapnr = dump_paddr_to_pfn(s, last_block->target_end);
 }
 
 static DumpState dump_state_global = { .status = DUMP_STATUS_NONE };
 
 static void dump_state_prepare(DumpState *s)
 {
     /* zero the struct, setting status to active */
     *s = (DumpState) { .status = DUMP_STATUS_ACTIVE };
 }
 
 bool qemu_system_dump_in_progress(void)
 {
     DumpState *state = &dump_state_global;
     return (qatomic_read(&state->status) == DUMP_STATUS_ACTIVE);
 }
 
 /*
  * calculate total size of memory to be dumped (taking filter into
  * account.)
  */
 static int64_t dump_calculate_size(DumpState *s)
 {
     GuestPhysBlock *block;
     int64_t total = 0;
 
     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
         total += dump_filtered_memblock_size(block,
                                              s->filter_area_begin,
                                              s->filter_area_length);
     }
 
     return total;
 }
 
 static void vmcoreinfo_update_phys_base(DumpState *s)
 {
     uint64_t size, note_head_size, name_size, phys_base;
     char **lines;
     uint8_t *vmci;
     size_t i;
 
     if (!note_name_equal(s, s->guest_note, "VMCOREINFO")) {
         return;
     }
 
     get_note_sizes(s, s->guest_note, &note_head_size, &name_size, &size);
     note_head_size = ROUND_UP(note_head_size, 4);
 
     vmci = s->guest_note + note_head_size + ROUND_UP(name_size, 4);
     *(vmci + size) = '\0';
 
     lines = g_strsplit((char *)vmci, "\n", -1);
     for (i = 0; lines[i]; i++) {
         const char *prefix = NULL;
 
         if (s->dump_info.d_machine == EM_X86_64) {
             prefix = "NUMBER(phys_base)=";
         } else if (s->dump_info.d_machine == EM_AARCH64) {
             prefix = "NUMBER(PHYS_OFFSET)=";
         }
 
         if (prefix && g_str_has_prefix(lines[i], prefix)) {
             if (qemu_strtou64(lines[i] + strlen(prefix), NULL, 16,
                               &phys_base) < 0) {
                 warn_report("Failed to read %s", prefix);
             } else {
                 s->dump_info.phys_base = phys_base;
             }
             break;
         }
     }
 
     g_strfreev(lines);
 }
 
 static void dump_init(DumpState *s, int fd, bool has_format,
                       DumpGuestMemoryFormat format, bool paging, bool has_filter,
                       int64_t begin, int64_t length, Error **errp)
 {
     ERRP_GUARD();
     VMCoreInfoState *vmci = vmcoreinfo_find();
     CPUState *cpu;
     int nr_cpus;
     int ret;
 
     s->has_format = has_format;
     s->format = format;
     s->written_size = 0;
 
     /* kdump-compressed is conflict with paging and filter */
     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
         assert(!paging && !has_filter);
     }
 
     if (runstate_is_running()) {
         vm_stop(RUN_STATE_SAVE_VM);
         s->resume = true;
     } else {
         s->resume = false;
     }
 
     /* If we use KVM, we should synchronize the registers before we get dump
      * info or physmap info.
      */
     cpu_synchronize_all_states();
     nr_cpus = 0;
     CPU_FOREACH(cpu) {
         nr_cpus++;
     }
 
     s->fd = fd;
     if (has_filter && !length) {
         error_setg(errp, QERR_INVALID_PARAMETER, "length");
         goto cleanup;
     }
     s->filter_area_begin = begin;
     s->filter_area_length = length;
 
     /* First index is 0, it's the special null name */
     s->string_table_buf = g_array_new(FALSE, TRUE, 1);
     /*
      * Allocate the null name, due to the clearing option set to true
      * it will be 0.
      */
     g_array_set_size(s->string_table_buf, 1);
 
     memory_mapping_list_init(&s->list);
 
     guest_phys_blocks_init(&s->guest_phys_blocks);
     guest_phys_blocks_append(&s->guest_phys_blocks);
     s->total_size = dump_calculate_size(s);
 #ifdef DEBUG_DUMP_GUEST_MEMORY
     fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
 #endif
 
     /* it does not make sense to dump non-existent memory */
     if (!s->total_size) {
         error_setg(errp, "dump: no guest memory to dump");
         goto cleanup;
     }
 
     /* Is the filter filtering everything? */
     if (validate_start_block(s) == -1) {
         error_setg(errp, QERR_INVALID_PARAMETER, "begin");
         goto cleanup;
     }
 
     /* get dump info: endian, class and architecture.
      * If the target architecture is not supported, cpu_get_dump_info() will
      * return -1.
      */
     ret = cpu_get_dump_info(&s->dump_info, &s->guest_phys_blocks);
     if (ret < 0) {
         error_setg(errp, QERR_UNSUPPORTED);
         goto cleanup;
     }
 
     if (!s->dump_info.page_size) {
         s->dump_info.page_size = TARGET_PAGE_SIZE;
     }
 
     s->note_size = cpu_get_note_size(s->dump_info.d_class,
                                      s->dump_info.d_machine, nr_cpus);
     if (s->note_size < 0) {
         error_setg(errp, QERR_UNSUPPORTED);
         goto cleanup;
     }
 
     /*
      * The goal of this block is to (a) update the previously guessed
      * phys_base, (b) copy the guest note out of the guest.
      * Failure to do so is not fatal for dumping.
      */
     if (vmci) {
         uint64_t addr, note_head_size, name_size, desc_size;
         uint32_t size;
         uint16_t format;
 
         note_head_size = dump_is_64bit(s) ?
             sizeof(Elf64_Nhdr) : sizeof(Elf32_Nhdr);
 
         format = le16_to_cpu(vmci->vmcoreinfo.guest_format);
         size = le32_to_cpu(vmci->vmcoreinfo.size);
         addr = le64_to_cpu(vmci->vmcoreinfo.paddr);
         if (!vmci->has_vmcoreinfo) {
             warn_report("guest note is not present");
         } else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) {
             warn_report("guest note size is invalid: %" PRIu32, size);
         } else if (format != FW_CFG_VMCOREINFO_FORMAT_ELF) {
             warn_report("guest note format is unsupported: %" PRIu16, format);
         } else {
             s->guest_note = g_malloc(size + 1); /* +1 for adding \0 */
             cpu_physical_memory_read(addr, s->guest_note, size);
 
             get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_size);
             s->guest_note_size = ELF_NOTE_SIZE(note_head_size, name_size,
                                                desc_size);
             if (name_size > MAX_GUEST_NOTE_SIZE ||
                 desc_size > MAX_GUEST_NOTE_SIZE ||
                 s->guest_note_size > size) {
                 warn_report("Invalid guest note header");
                 g_free(s->guest_note);
                 s->guest_note = NULL;
             } else {
                 vmcoreinfo_update_phys_base(s);
                 s->note_size += s->guest_note_size;
             }
         }
     }
 
     /* get memory mapping */
     if (paging) {
         qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, errp);
         if (*errp) {
             goto cleanup;
         }
     } else {
         qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
     }
 
     s->nr_cpus = nr_cpus;
 
     get_max_mapnr(s);
 
     uint64_t tmp;
     tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT),
                        s->dump_info.page_size);
     s->len_dump_bitmap = tmp * s->dump_info.page_size;
 
     /* init for kdump-compressed format */
     if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
         switch (format) {
         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
             s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
             break;
 
         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
 #ifdef CONFIG_LZO
             if (lzo_init() != LZO_E_OK) {
                 error_setg(errp, "failed to initialize the LZO library");
                 goto cleanup;
             }
 #endif
             s->flag_compress = DUMP_DH_COMPRESSED_LZO;
             break;
 
         case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
             s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
             break;
 
         default:
             s->flag_compress = 0;
         }
 
         return;
     }
 
     if (dump_has_filter(s)) {
         memory_mapping_filter(&s->list, s->filter_area_begin, s->filter_area_length);
     }
 
     /*
      * The first section header is always a special one in which most
      * fields are 0. The section header string table is also always
      * set.
      */
     s->shdr_num = 2;
 
     /*
      * Adds the number of architecture sections to shdr_num and sets
      * elf_section_data_size so we know the offsets and sizes of all
      * parts.
      */
     if (s->dump_info.arch_sections_add_fn) {
         s->dump_info.arch_sections_add_fn(s);
     }
 
     /*
      * calculate shdr_num so we know the offsets and sizes of all
      * parts.
      * Calculate phdr_num
      *
      * The absolute maximum amount of phdrs is UINT32_MAX - 1 as
      * sh_info is 32 bit. There's special handling once we go over
      * UINT16_MAX - 1 but that is handled in the ehdr and section
      * code.
      */
     s->phdr_num = 1; /* Reserve PT_NOTE */
     if (s->list.num <= UINT32_MAX - 1) {
         s->phdr_num += s->list.num;
     } else {
         s->phdr_num = UINT32_MAX;
     }
 
     /*
      * Now that the number of section and program headers is known we
      * can calculate the offsets of the headers and data.
      */
     if (dump_is_64bit(s)) {
         s->shdr_offset = sizeof(Elf64_Ehdr);
         s->phdr_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
         s->note_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
     } else {
         s->shdr_offset = sizeof(Elf32_Ehdr);
         s->phdr_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
         s->note_offset = s->phdr_offset + sizeof(Elf32_Phdr) * s->phdr_num;
     }
     s->memory_offset = s->note_offset + s->note_size;
     s->section_offset = s->memory_offset + s->total_size;
 
     return;
 
 cleanup:
     dump_cleanup(s);
 }
 
 /* this operation might be time consuming. */
 static void dump_process(DumpState *s, Error **errp)
 {
     ERRP_GUARD();
     DumpQueryResult *result = NULL;
 
     if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
 #ifdef TARGET_X86_64
         create_win_dump(s, errp);
 #endif
     } else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
         create_kdump_vmcore(s, errp);
     } else {
         create_vmcore(s, errp);
     }
 
     /* make sure status is written after written_size updates */
     smp_wmb();
     qatomic_set(&s->status,
                (*errp ? DUMP_STATUS_FAILED : DUMP_STATUS_COMPLETED));
 
     /* send DUMP_COMPLETED message (unconditionally) */
     result = qmp_query_dump(NULL);
     /* should never fail */
     assert(result);
     qapi_event_send_dump_completed(result, !!*errp, (*errp ?
                                                      error_get_pretty(*errp) : NULL));
     qapi_free_DumpQueryResult(result);
 
     dump_cleanup(s);
 }
 
 static void *dump_thread(void *data)
 {
     DumpState *s = (DumpState *)data;
     dump_process(s, NULL);
     return NULL;
 }
 
 DumpQueryResult *qmp_query_dump(Error **errp)
 {
     DumpQueryResult *result = g_new(DumpQueryResult, 1);
     DumpState *state = &dump_state_global;
     result->status = qatomic_read(&state->status);
     /* make sure we are reading status and written_size in order */
     smp_rmb();
     result->completed = state->written_size;
     result->total = state->total_size;
     return result;
 }
 
 void qmp_dump_guest_memory(bool paging, const char *file,
                            bool has_detach, bool detach,
                            bool has_begin, int64_t begin, bool has_length,
                            int64_t length, bool has_format,
                            DumpGuestMemoryFormat format, Error **errp)
 {
     ERRP_GUARD();
     const char *p;
     int fd = -1;
     DumpState *s;
     bool detach_p = false;
 
     if (runstate_check(RUN_STATE_INMIGRATE)) {
         error_setg(errp, "Dump not allowed during incoming migration.");
         return;
     }
 
     /* if there is a dump in background, we should wait until the dump
      * finished */
     if (qemu_system_dump_in_progress()) {
         error_setg(errp, "There is a dump in process, please wait.");
         return;
     }
 
     /*
      * kdump-compressed format need the whole memory dumped, so paging or
      * filter is not supported here.
      */
     if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
         (paging || has_begin || has_length)) {
         error_setg(errp, "kdump-compressed format doesn't support paging or "
                          "filter");
         return;
     }
     if (has_begin && !has_length) {
         error_setg(errp, QERR_MISSING_PARAMETER, "length");
         return;
     }
     if (!has_begin && has_length) {
         error_setg(errp, QERR_MISSING_PARAMETER, "begin");
         return;
     }
     if (has_detach) {
         detach_p = detach;
     }
 
     /* check whether lzo/snappy is supported */
 #ifndef CONFIG_LZO
     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
         error_setg(errp, "kdump-lzo is not available now");
         return;
     }
 #endif
 
 #ifndef CONFIG_SNAPPY
     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
         error_setg(errp, "kdump-snappy is not available now");
         return;
     }
 #endif
 
 #ifndef TARGET_X86_64
     if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
         error_setg(errp, "Windows dump is only available for x86-64");
         return;
     }
 #endif
 
 #if !defined(WIN32)
     if (strstart(file, "fd:", &p)) {
         fd = monitor_get_fd(monitor_cur(), p, errp);
         if (fd == -1) {
             return;
         }
     }
 #endif
 
     if  (strstart(file, "file:", &p)) {
         fd = qemu_open_old(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
         if (fd < 0) {
             error_setg_file_open(errp, errno, p);
             return;
         }
     }
 
     if (fd == -1) {
         error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
         return;
     }
 
     if (!dump_migration_blocker) {
         error_setg(&dump_migration_blocker,
                    "Live migration disabled: dump-guest-memory in progress");
     }
 
     /*
      * Allows even for -only-migratable, but forbid migration during the
      * process of dump guest memory.
      */
     if (migrate_add_blocker_internal(dump_migration_blocker, errp)) {
         /* Remember to release the fd before passing it over to dump state */
         close(fd);
         return;
     }
 
     s = &dump_state_global;
     dump_state_prepare(s);
 
     dump_init(s, fd, has_format, format, paging, has_begin,
               begin, length, errp);
     if (*errp) {
         qatomic_set(&s->status, DUMP_STATUS_FAILED);
         return;
     }
 
     if (detach_p) {
         /* detached dump */
         s->detached = true;
         qemu_thread_create(&s->dump_thread, "dump_thread", dump_thread,
                            s, QEMU_THREAD_DETACHED);
     } else {
         /* sync dump */
         dump_process(s, errp);
     }
 }
 
 DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
 {
     DumpGuestMemoryCapability *cap =
                                   g_new0(DumpGuestMemoryCapability, 1);
     DumpGuestMemoryFormatList **tail = &cap->formats;
 
     /* elf is always available */
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_ELF);
 
     /* kdump-zlib is always available */
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB);
 
     /* add new item if kdump-lzo is available */
 #ifdef CONFIG_LZO
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO);
 #endif
 
     /* add new item if kdump-snappy is available */
 #ifdef CONFIG_SNAPPY
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
 #endif
 
     /* Windows dump is available only if target is x86_64 */
 #ifdef TARGET_X86_64
     QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
 #endif
 
     return cap;
 }