dump.c - qemu - Git at Google

 /*
  * 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-common.h"
 #include "elf.h"
 #include "cpu.h"
 #include "exec/cpu-all.h"
 #include "exec/hwaddr.h"
 #include "monitor/monitor.h"
 #include "sysemu/kvm.h"
 #include "sysemu/dump.h"
 #include "sysemu/sysemu.h"
 #include "sysemu/memory_mapping.h"
 #include "sysemu/cpus.h"
 #include "qapi/error.h"
 #include "qmp-commands.h"

 static uint16_t cpu_convert_to_target16(uint16_t val, int endian)
 {
     if (endian == ELFDATA2LSB) {
         val = cpu_to_le16(val);
     } else {
         val = cpu_to_be16(val);
     }

     return val;
 }

 static uint32_t cpu_convert_to_target32(uint32_t val, int endian)
 {
     if (endian == ELFDATA2LSB) {
         val = cpu_to_le32(val);
     } else {
         val = cpu_to_be32(val);
     }

     return val;
 }

 static uint64_t cpu_convert_to_target64(uint64_t val, int endian)
 {
     if (endian == ELFDATA2LSB) {
         val = cpu_to_le64(val);
     } else {
         val = cpu_to_be64(val);
     }

     return val;
 }

 typedef struct DumpState {
     GuestPhysBlockList guest_phys_blocks;
     ArchDumpInfo dump_info;
     MemoryMappingList list;
     uint16_t phdr_num;
     uint32_t sh_info;
     bool have_section;
     bool resume;
     ssize_t note_size;
     hwaddr memory_offset;
     int fd;

     GuestPhysBlock *next_block;
     ram_addr_t start;
     bool has_filter;
     int64_t begin;
     int64_t length;
     Error **errp;
 } DumpState;

 static int dump_cleanup(DumpState *s)
 {
     int ret = 0;

     guest_phys_blocks_free(&s->guest_phys_blocks);
     memory_mapping_list_free(&s->list);
     if (s->fd != -1) {
         close(s->fd);
     }
     if (s->resume) {
         vm_start();
     }

     return ret;
 }

 static void dump_error(DumpState *s, const char *reason)
 {
     dump_cleanup(s);
 }

 static int fd_write_vmcore(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 -1;
     }

     return 0;
 }

 static int write_elf64_header(DumpState *s)
 {
     Elf64_Ehdr elf_header;
     int ret;
     int endian = s->dump_info.d_endian;

     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_convert_to_target16(ET_CORE, endian);
     elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
                                                    endian);
     elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
     elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
     elf_header.e_phoff = cpu_convert_to_target64(sizeof(Elf64_Ehdr), endian);
     elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf64_Phdr),
                                                      endian);
     elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
     if (s->have_section) {
         uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;

         elf_header.e_shoff = cpu_convert_to_target64(shoff, endian);
         elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf64_Shdr),
                                                          endian);
         elf_header.e_shnum = cpu_convert_to_target16(1, endian);
     }

     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write elf header.\n");
         return -1;
     }

     return 0;
 }

 static int write_elf32_header(DumpState *s)
 {
     Elf32_Ehdr elf_header;
     int ret;
     int endian = s->dump_info.d_endian;

     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] = endian;
     elf_header.e_ident[EI_VERSION] = EV_CURRENT;
     elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
     elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
                                                    endian);
     elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
     elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
     elf_header.e_phoff = cpu_convert_to_target32(sizeof(Elf32_Ehdr), endian);
     elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf32_Phdr),
                                                      endian);
     elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
     if (s->have_section) {
         uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;

         elf_header.e_shoff = cpu_convert_to_target32(shoff, endian);
         elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf32_Shdr),
                                                          endian);
         elf_header.e_shnum = cpu_convert_to_target16(1, endian);
     }

     ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write elf header.\n");
         return -1;
     }

     return 0;
 }

 static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
                             hwaddr filesz)
 {
     Elf64_Phdr phdr;
     int ret;
     int endian = s->dump_info.d_endian;

     memset(&phdr, 0, sizeof(Elf64_Phdr));
     phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
     phdr.p_offset = cpu_convert_to_target64(offset, endian);
     phdr.p_paddr = cpu_convert_to_target64(memory_mapping->phys_addr, endian);
     phdr.p_filesz = cpu_convert_to_target64(filesz, endian);
     phdr.p_memsz = cpu_convert_to_target64(memory_mapping->length, endian);
     phdr.p_vaddr = cpu_convert_to_target64(memory_mapping->virt_addr, endian);

     assert(memory_mapping->length >= filesz);

     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table.\n");
         return -1;
     }

     return 0;
 }

 static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
                             int phdr_index, hwaddr offset,
                             hwaddr filesz)
 {
     Elf32_Phdr phdr;
     int ret;
     int endian = s->dump_info.d_endian;

     memset(&phdr, 0, sizeof(Elf32_Phdr));
     phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
     phdr.p_offset = cpu_convert_to_target32(offset, endian);
     phdr.p_paddr = cpu_convert_to_target32(memory_mapping->phys_addr, endian);
     phdr.p_filesz = cpu_convert_to_target32(filesz, endian);
     phdr.p_memsz = cpu_convert_to_target32(memory_mapping->length, endian);
     phdr.p_vaddr = cpu_convert_to_target32(memory_mapping->virt_addr, endian);

     assert(memory_mapping->length >= filesz);

     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table.\n");
         return -1;
     }

     return 0;
 }

 static int write_elf64_note(DumpState *s)
 {
     Elf64_Phdr phdr;
     int endian = s->dump_info.d_endian;
     hwaddr begin = s->memory_offset - s->note_size;
     int ret;

     memset(&phdr, 0, sizeof(Elf64_Phdr));
     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
     phdr.p_offset = cpu_convert_to_target64(begin, endian);
     phdr.p_paddr = 0;
     phdr.p_filesz = cpu_convert_to_target64(s->note_size, endian);
     phdr.p_memsz = cpu_convert_to_target64(s->note_size, endian);
     phdr.p_vaddr = 0;

     ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table.\n");
         return -1;
     }

     return 0;
 }

 static inline int cpu_index(CPUState *cpu)
 {
     return cpu->cpu_index + 1;
 }

 static int write_elf64_notes(DumpState *s)
 {
     CPUState *cpu;
     int ret;
     int id;

     CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write elf notes.\n");
             return -1;
         }
     }

     CPU_FOREACH(cpu) {
         ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
             return -1;
         }
     }

     return 0;
 }

 static int write_elf32_note(DumpState *s)
 {
     hwaddr begin = s->memory_offset - s->note_size;
     Elf32_Phdr phdr;
     int endian = s->dump_info.d_endian;
     int ret;

     memset(&phdr, 0, sizeof(Elf32_Phdr));
     phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
     phdr.p_offset = cpu_convert_to_target32(begin, endian);
     phdr.p_paddr = 0;
     phdr.p_filesz = cpu_convert_to_target32(s->note_size, endian);
     phdr.p_memsz = cpu_convert_to_target32(s->note_size, endian);
     phdr.p_vaddr = 0;

     ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write program header table.\n");
         return -1;
     }

     return 0;
 }

 static int write_elf32_notes(DumpState *s)
 {
     CPUState *cpu;
     int ret;
     int id;

     CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
         ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write elf notes.\n");
             return -1;
         }
     }

     CPU_FOREACH(cpu) {
         ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
             return -1;
         }
     }

     return 0;
 }

 static int write_elf_section(DumpState *s, int type)
 {
     Elf32_Shdr shdr32;
     Elf64_Shdr shdr64;
     int endian = s->dump_info.d_endian;
     int shdr_size;
     void *shdr;
     int ret;

     if (type == 0) {
         shdr_size = sizeof(Elf32_Shdr);
         memset(&shdr32, 0, shdr_size);
         shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
         shdr = &shdr32;
     } else {
         shdr_size = sizeof(Elf64_Shdr);
         memset(&shdr64, 0, shdr_size);
         shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
         shdr = &shdr64;
     }

     ret = fd_write_vmcore(&shdr, shdr_size, s);
     if (ret < 0) {
         dump_error(s, "dump: failed to write section header table.\n");
         return -1;
     }

     return 0;
 }

 static int write_data(DumpState *s, void *buf, int length)
 {
     int ret;

     ret = fd_write_vmcore(buf, length, s);
     if (ret < 0) {
         dump_error(s, "dump: failed to save memory.\n");
         return -1;
     }

     return 0;
 }

 /* write the memroy to vmcore. 1 page per I/O. */
 static int write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
                         int64_t size)
 {
     int64_t i;
     int ret;

     for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
         ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
                          TARGET_PAGE_SIZE);
         if (ret < 0) {
             return ret;
         }
     }

     if ((size % TARGET_PAGE_SIZE) != 0) {
         ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
                          size % TARGET_PAGE_SIZE);
         if (ret < 0) {
             return ret;
         }
     }

     return 0;
 }

 /* 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 (s->has_filter) {
         if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
             return;
         }
     }

     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
         if (s->has_filter) {
             if (block->target_start >= s->begin + s->length ||
                 block->target_end <= s->begin) {
                 /* This block is out of the range */
                 continue;
             }

             if (s->begin <= block->target_start) {
                 start = block->target_start;
             } else {
                 start = s->begin;
             }

             size_in_block = block->target_end - start;
             if (s->begin + s->length < block->target_end) {
                 size_in_block -= block->target_end - (s->begin + s->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 int write_elf_loads(DumpState *s)
 {
     hwaddr offset, filesz;
     MemoryMapping *memory_mapping;
     uint32_t phdr_index = 1;
     int ret;
     uint32_t max_index;

     if (s->have_section) {
         max_index = s->sh_info;
     } else {
         max_index = s->phdr_num;
     }

     QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
         get_offset_range(memory_mapping->phys_addr,
                          memory_mapping->length,
                          s, &offset, &filesz);
         if (s->dump_info.d_class == ELFCLASS64) {
             ret = write_elf64_load(s, memory_mapping, phdr_index++, offset,
                                    filesz);
         } else {
             ret = write_elf32_load(s, memory_mapping, phdr_index++, offset,
                                    filesz);
         }

         if (ret < 0) {
             return -1;
         }

         if (phdr_index >= max_index) {
             break;
         }
     }

     return 0;
 }

 /* write elf header, PT_NOTE and elf note to vmcore. */
 static int dump_begin(DumpState *s)
 {
     int ret;

     /*
      * the vmcore's format is:
      *   --------------
      *   |  elf header |
      *   --------------
      *   |  PT_NOTE    |
      *   --------------
      *   |  PT_LOAD    |
      *   --------------
      *   |  ......     |
      *   --------------
      *   |  PT_LOAD    |
      *   --------------
      *   |  sec_hdr    |
      *   --------------
      *   |  elf note   |
      *   --------------
      *   |  memory     |
      *   --------------
      *
      * we only know where the memory is saved after we write elf note into
      * vmcore.
      */

     /* write elf header to vmcore */
     if (s->dump_info.d_class == ELFCLASS64) {
         ret = write_elf64_header(s);
     } else {
         ret = write_elf32_header(s);
     }
     if (ret < 0) {
         return -1;
     }

     if (s->dump_info.d_class == ELFCLASS64) {
         /* write PT_NOTE to vmcore */
         if (write_elf64_note(s) < 0) {
             return -1;
         }

         /* write all PT_LOAD to vmcore */
         if (write_elf_loads(s) < 0) {
             return -1;
         }

         /* write section to vmcore */
         if (s->have_section) {
             if (write_elf_section(s, 1) < 0) {
                 return -1;
             }
         }

         /* write notes to vmcore */
         if (write_elf64_notes(s) < 0) {
             return -1;
         }

     } else {
         /* write PT_NOTE to vmcore */
         if (write_elf32_note(s) < 0) {
             return -1;
         }

         /* write all PT_LOAD to vmcore */
         if (write_elf_loads(s) < 0) {
             return -1;
         }

         /* write section to vmcore */
         if (s->have_section) {
             if (write_elf_section(s, 0) < 0) {
                 return -1;
             }
         }

         /* write notes to vmcore */
         if (write_elf32_notes(s) < 0) {
             return -1;
         }
     }

     return 0;
 }

 /* write PT_LOAD to vmcore */
 static int dump_completed(DumpState *s)
 {
     dump_cleanup(s);
     return 0;
 }

 static int get_next_block(DumpState *s, GuestPhysBlock *block)
 {
     while (1) {
         block = QTAILQ_NEXT(block, next);
         if (!block) {
             /* no more block */
             return 1;
         }

         s->start = 0;
         s->next_block = block;
         if (s->has_filter) {
             if (block->target_start >= s->begin + s->length ||
                 block->target_end <= s->begin) {
                 /* This block is out of the range */
                 continue;
             }

             if (s->begin > block->target_start) {
                 s->start = s->begin - block->target_start;
             }
         }

         return 0;
     }
 }

 /* write all memory to vmcore */
 static int dump_iterate(DumpState *s)
 {
     GuestPhysBlock *block;
     int64_t size;
     int ret;

     while (1) {
         block = s->next_block;

         size = block->target_end - block->target_start;
         if (s->has_filter) {
             size -= s->start;
             if (s->begin + s->length < block->target_end) {
                 size -= block->target_end - (s->begin + s->length);
             }
         }
         ret = write_memory(s, block, s->start, size);
         if (ret == -1) {
             return ret;
         }

         ret = get_next_block(s, block);
         if (ret == 1) {
             dump_completed(s);
             return 0;
         }
     }
 }

 static int create_vmcore(DumpState *s)
 {
     int ret;

     ret = dump_begin(s);
     if (ret < 0) {
         return -1;
     }

     ret = dump_iterate(s);
     if (ret < 0) {
         return -1;
     }

     return 0;
 }

 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;

     if (!s->has_filter) {
         s->next_block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
         return 0;
     }

     QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
         if (block->target_start >= s->begin + s->length ||
             block->target_end <= s->begin) {
             /* This block is out of the range */
             continue;
         }

         s->next_block = block;
         if (s->begin > block->target_start) {
             s->start = s->begin - block->target_start;
         } else {
             s->start = 0;
         }
         return s->start;
     }

     return -1;
 }

 static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
                      int64_t begin, int64_t length, Error **errp)
 {
     CPUState *cpu;
     int nr_cpus;
     Error *err = NULL;
     int ret;

     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->errp = errp;
     s->fd = fd;
     s->has_filter = has_filter;
     s->begin = begin;
     s->length = length;

     guest_phys_blocks_init(&s->guest_phys_blocks);
     guest_phys_blocks_append(&s->guest_phys_blocks);

     s->start = get_start_block(s);
     if (s->start == -1) {
         error_set(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_set(errp, QERR_UNSUPPORTED);
         goto cleanup;
     }

     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_set(errp, QERR_UNSUPPORTED);
         goto cleanup;
     }

     /* get memory mapping */
     memory_mapping_list_init(&s->list);
     if (paging) {
         qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, &err);
         if (err != NULL) {
             error_propagate(errp, err);
             goto cleanup;
         }
     } else {
         qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
     }

     if (s->has_filter) {
         memory_mapping_filter(&s->list, s->begin, s->length);
     }

     /*
      * calculate phdr_num
      *
      * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
      */
     s->phdr_num = 1; /* PT_NOTE */
     if (s->list.num < UINT16_MAX - 2) {
         s->phdr_num += s->list.num;
         s->have_section = false;
     } else {
         s->have_section = true;
         s->phdr_num = PN_XNUM;
         s->sh_info = 1; /* PT_NOTE */

         /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
         if (s->list.num <= UINT32_MAX - 1) {
             s->sh_info += s->list.num;
         } else {
             s->sh_info = UINT32_MAX;
         }
     }

     if (s->dump_info.d_class == ELFCLASS64) {
         if (s->have_section) {
             s->memory_offset = sizeof(Elf64_Ehdr) +
                                sizeof(Elf64_Phdr) * s->sh_info +
                                sizeof(Elf64_Shdr) + s->note_size;
         } else {
             s->memory_offset = sizeof(Elf64_Ehdr) +
                                sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;
         }
     } else {
         if (s->have_section) {
             s->memory_offset = sizeof(Elf32_Ehdr) +
                                sizeof(Elf32_Phdr) * s->sh_info +
                                sizeof(Elf32_Shdr) + s->note_size;
         } else {
             s->memory_offset = sizeof(Elf32_Ehdr) +
                                sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;
         }
     }

     return 0;

 cleanup:
     guest_phys_blocks_free(&s->guest_phys_blocks);

     if (s->resume) {
         vm_start();
     }

     return -1;
 }

 void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
                            int64_t begin, bool has_length, int64_t length,
                            Error **errp)
 {
     const char *p;
     int fd = -1;
     DumpState *s;
     int ret;

     if (has_begin && !has_length) {
         error_set(errp, QERR_MISSING_PARAMETER, "length");
         return;
     }
     if (!has_begin && has_length) {
         error_set(errp, QERR_MISSING_PARAMETER, "begin");
         return;
     }

 #if !defined(WIN32)
     if (strstart(file, "fd:", &p)) {
         fd = monitor_get_fd(cur_mon, p, errp);
         if (fd == -1) {
             return;
         }
     }
 #endif

     if  (strstart(file, "file:", &p)) {
         fd = qemu_open(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_set(errp, QERR_INVALID_PARAMETER, "protocol");
         return;
     }

     s = g_malloc0(sizeof(DumpState));

     ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
     if (ret < 0) {
         g_free(s);
         return;
     }

     if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
         error_set(errp, QERR_IO_ERROR);
     }

     g_free(s);
 }
	/*
	* 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-common.h"
	#include "elf.h"
	#include "cpu.h"
	#include "exec/cpu-all.h"
	#include "exec/hwaddr.h"
	#include "monitor/monitor.h"
	#include "sysemu/kvm.h"
	#include "sysemu/dump.h"
	#include "sysemu/sysemu.h"
	#include "sysemu/memory_mapping.h"
	#include "sysemu/cpus.h"
	#include "qapi/error.h"
	#include "qmp-commands.h"

	static uint16_t cpu_convert_to_target16(uint16_t val, int endian)
	{
	if (endian == ELFDATA2LSB) {
	val = cpu_to_le16(val);
	} else {
	val = cpu_to_be16(val);
	}

	return val;
	}

	static uint32_t cpu_convert_to_target32(uint32_t val, int endian)
	{
	if (endian == ELFDATA2LSB) {
	val = cpu_to_le32(val);
	} else {
	val = cpu_to_be32(val);
	}

	return val;
	}

	static uint64_t cpu_convert_to_target64(uint64_t val, int endian)
	{
	if (endian == ELFDATA2LSB) {
	val = cpu_to_le64(val);
	} else {
	val = cpu_to_be64(val);
	}

	return val;
	}

	typedef struct DumpState {
	GuestPhysBlockList guest_phys_blocks;
	ArchDumpInfo dump_info;
	MemoryMappingList list;
	uint16_t phdr_num;
	uint32_t sh_info;
	bool have_section;
	bool resume;
	ssize_t note_size;
	hwaddr memory_offset;
	int fd;

	GuestPhysBlock *next_block;
	ram_addr_t start;
	bool has_filter;
	int64_t begin;
	int64_t length;
	Error **errp;
	} DumpState;

	static int dump_cleanup(DumpState *s)
	{
	int ret = 0;

	guest_phys_blocks_free(&s->guest_phys_blocks);
	memory_mapping_list_free(&s->list);
	if (s->fd != -1) {
	close(s->fd);
	}
	if (s->resume) {
	vm_start();
	}

	return ret;
	}

	static void dump_error(DumpState s, const char reason)
	{
	dump_cleanup(s);
	}

	static int fd_write_vmcore(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 -1;
	}

	return 0;
	}

	static int write_elf64_header(DumpState *s)
	{
	Elf64_Ehdr elf_header;
	int ret;
	int endian = s->dump_info.d_endian;

	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_convert_to_target16(ET_CORE, endian);
	elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
	endian);
	elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
	elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
	elf_header.e_phoff = cpu_convert_to_target64(sizeof(Elf64_Ehdr), endian);
	elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf64_Phdr),
	endian);
	elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
	if (s->have_section) {
	uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;

	elf_header.e_shoff = cpu_convert_to_target64(shoff, endian);
	elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf64_Shdr),
	endian);
	elf_header.e_shnum = cpu_convert_to_target16(1, endian);
	}

	ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write elf header.\n");
	return -1;
	}

	return 0;
	}

	static int write_elf32_header(DumpState *s)
	{
	Elf32_Ehdr elf_header;
	int ret;
	int endian = s->dump_info.d_endian;

	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] = endian;
	elf_header.e_ident[EI_VERSION] = EV_CURRENT;
	elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
	elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
	endian);
	elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
	elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
	elf_header.e_phoff = cpu_convert_to_target32(sizeof(Elf32_Ehdr), endian);
	elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf32_Phdr),
	endian);
	elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
	if (s->have_section) {
	uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;

	elf_header.e_shoff = cpu_convert_to_target32(shoff, endian);
	elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf32_Shdr),
	endian);
	elf_header.e_shnum = cpu_convert_to_target16(1, endian);
	}

	ret = fd_write_vmcore(&elf_header, sizeof(elf_header), s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write elf header.\n");
	return -1;
	}

	return 0;
	}

	static int write_elf64_load(DumpState s, MemoryMapping memory_mapping,
	int phdr_index, hwaddr offset,
	hwaddr filesz)
	{
	Elf64_Phdr phdr;
	int ret;
	int endian = s->dump_info.d_endian;

	memset(&phdr, 0, sizeof(Elf64_Phdr));
	phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
	phdr.p_offset = cpu_convert_to_target64(offset, endian);
	phdr.p_paddr = cpu_convert_to_target64(memory_mapping->phys_addr, endian);
	phdr.p_filesz = cpu_convert_to_target64(filesz, endian);
	phdr.p_memsz = cpu_convert_to_target64(memory_mapping->length, endian);
	phdr.p_vaddr = cpu_convert_to_target64(memory_mapping->virt_addr, endian);

	assert(memory_mapping->length >= filesz);

	ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write program header table.\n");
	return -1;
	}

	return 0;
	}

	static int write_elf32_load(DumpState s, MemoryMapping memory_mapping,
	int phdr_index, hwaddr offset,
	hwaddr filesz)
	{
	Elf32_Phdr phdr;
	int ret;
	int endian = s->dump_info.d_endian;

	memset(&phdr, 0, sizeof(Elf32_Phdr));
	phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
	phdr.p_offset = cpu_convert_to_target32(offset, endian);
	phdr.p_paddr = cpu_convert_to_target32(memory_mapping->phys_addr, endian);
	phdr.p_filesz = cpu_convert_to_target32(filesz, endian);
	phdr.p_memsz = cpu_convert_to_target32(memory_mapping->length, endian);
	phdr.p_vaddr = cpu_convert_to_target32(memory_mapping->virt_addr, endian);

	assert(memory_mapping->length >= filesz);

	ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write program header table.\n");
	return -1;
	}

	return 0;
	}

	static int write_elf64_note(DumpState *s)
	{
	Elf64_Phdr phdr;
	int endian = s->dump_info.d_endian;
	hwaddr begin = s->memory_offset - s->note_size;
	int ret;

	memset(&phdr, 0, sizeof(Elf64_Phdr));
	phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
	phdr.p_offset = cpu_convert_to_target64(begin, endian);
	phdr.p_paddr = 0;
	phdr.p_filesz = cpu_convert_to_target64(s->note_size, endian);
	phdr.p_memsz = cpu_convert_to_target64(s->note_size, endian);
	phdr.p_vaddr = 0;

	ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write program header table.\n");
	return -1;
	}

	return 0;
	}

	static inline int cpu_index(CPUState *cpu)
	{
	return cpu->cpu_index + 1;
	}

	static int write_elf64_notes(DumpState *s)
	{
	CPUState *cpu;
	int ret;
	int id;

	CPU_FOREACH(cpu) {
	id = cpu_index(cpu);
	ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write elf notes.\n");
	return -1;
	}
	}

	CPU_FOREACH(cpu) {
	ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write CPU status.\n");
	return -1;
	}
	}

	return 0;
	}

	static int write_elf32_note(DumpState *s)
	{
	hwaddr begin = s->memory_offset - s->note_size;
	Elf32_Phdr phdr;
	int endian = s->dump_info.d_endian;
	int ret;

	memset(&phdr, 0, sizeof(Elf32_Phdr));
	phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
	phdr.p_offset = cpu_convert_to_target32(begin, endian);
	phdr.p_paddr = 0;
	phdr.p_filesz = cpu_convert_to_target32(s->note_size, endian);
	phdr.p_memsz = cpu_convert_to_target32(s->note_size, endian);
	phdr.p_vaddr = 0;

	ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write program header table.\n");
	return -1;
	}

	return 0;
	}

	static int write_elf32_notes(DumpState *s)
	{
	CPUState *cpu;
	int ret;
	int id;

	CPU_FOREACH(cpu) {
	id = cpu_index(cpu);
	ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write elf notes.\n");
	return -1;
	}
	}

	CPU_FOREACH(cpu) {
	ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write CPU status.\n");
	return -1;
	}
	}

	return 0;
	}

	static int write_elf_section(DumpState *s, int type)
	{
	Elf32_Shdr shdr32;
	Elf64_Shdr shdr64;
	int endian = s->dump_info.d_endian;
	int shdr_size;
	void *shdr;
	int ret;

	if (type == 0) {
	shdr_size = sizeof(Elf32_Shdr);
	memset(&shdr32, 0, shdr_size);
	shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
	shdr = &shdr32;
	} else {
	shdr_size = sizeof(Elf64_Shdr);
	memset(&shdr64, 0, shdr_size);
	shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
	shdr = &shdr64;
	}

	ret = fd_write_vmcore(&shdr, shdr_size, s);
	if (ret < 0) {
	dump_error(s, "dump: failed to write section header table.\n");
	return -1;
	}

	return 0;
	}

	static int write_data(DumpState s, void buf, int length)
	{
	int ret;

	ret = fd_write_vmcore(buf, length, s);
	if (ret < 0) {
	dump_error(s, "dump: failed to save memory.\n");
	return -1;
	}

	return 0;
	}

	/* write the memroy to vmcore. 1 page per I/O. */
	static int write_memory(DumpState s, GuestPhysBlock block, ram_addr_t start,
	int64_t size)
	{
	int64_t i;
	int ret;

	for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {
	ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
	TARGET_PAGE_SIZE);
	if (ret < 0) {
	return ret;
	}
	}

	if ((size % TARGET_PAGE_SIZE) != 0) {
	ret = write_data(s, block->host_addr + start + i * TARGET_PAGE_SIZE,
	size % TARGET_PAGE_SIZE);
	if (ret < 0) {
	return ret;
	}
	}

	return 0;
	}

	/* 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 (s->has_filter) {
	if (phys_addr < s->begin \|\| phys_addr >= s->begin + s->length) {
	return;
	}
	}

	QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
	if (s->has_filter) {
	if (block->target_start >= s->begin + s->length \|\|
	block->target_end <= s->begin) {
	/* This block is out of the range */
	continue;
	}

	if (s->begin <= block->target_start) {
	start = block->target_start;
	} else {
	start = s->begin;
	}

	size_in_block = block->target_end - start;
	if (s->begin + s->length < block->target_end) {
	size_in_block -= block->target_end - (s->begin + s->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 int write_elf_loads(DumpState *s)
	{
	hwaddr offset, filesz;
	MemoryMapping *memory_mapping;
	uint32_t phdr_index = 1;
	int ret;
	uint32_t max_index;

	if (s->have_section) {
	max_index = s->sh_info;
	} else {
	max_index = s->phdr_num;
	}

	QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
	get_offset_range(memory_mapping->phys_addr,
	memory_mapping->length,
	s, &offset, &filesz);
	if (s->dump_info.d_class == ELFCLASS64) {
	ret = write_elf64_load(s, memory_mapping, phdr_index++, offset,
	filesz);
	} else {
	ret = write_elf32_load(s, memory_mapping, phdr_index++, offset,
	filesz);
	}

	if (ret < 0) {
	return -1;
	}

	if (phdr_index >= max_index) {
	break;
	}
	}

	return 0;
	}

	/* write elf header, PT_NOTE and elf note to vmcore. */
	static int dump_begin(DumpState *s)
	{
	int ret;

	/*
	* the vmcore's format is:
	* --------------
	* \| elf header \|
	* --------------
	* \| PT_NOTE \|
	* --------------
	* \| PT_LOAD \|
	* --------------
	* \| ...... \|
	* --------------
	* \| PT_LOAD \|
	* --------------
	* \| sec_hdr \|
	* --------------
	* \| elf note \|
	* --------------
	* \| memory \|
	* --------------
	*
	* we only know where the memory is saved after we write elf note into
	* vmcore.
	*/

	/* write elf header to vmcore */
	if (s->dump_info.d_class == ELFCLASS64) {
	ret = write_elf64_header(s);
	} else {
	ret = write_elf32_header(s);
	}
	if (ret < 0) {
	return -1;
	}

	if (s->dump_info.d_class == ELFCLASS64) {
	/* write PT_NOTE to vmcore */
	if (write_elf64_note(s) < 0) {
	return -1;
	}

	/* write all PT_LOAD to vmcore */
	if (write_elf_loads(s) < 0) {
	return -1;
	}

	/* write section to vmcore */
	if (s->have_section) {
	if (write_elf_section(s, 1) < 0) {
	return -1;
	}
	}

	/* write notes to vmcore */
	if (write_elf64_notes(s) < 0) {
	return -1;
	}

	} else {
	/* write PT_NOTE to vmcore */
	if (write_elf32_note(s) < 0) {
	return -1;
	}

	/* write all PT_LOAD to vmcore */
	if (write_elf_loads(s) < 0) {
	return -1;
	}

	/* write section to vmcore */
	if (s->have_section) {
	if (write_elf_section(s, 0) < 0) {
	return -1;
	}
	}

	/* write notes to vmcore */
	if (write_elf32_notes(s) < 0) {
	return -1;
	}
	}

	return 0;
	}

	/* write PT_LOAD to vmcore */
	static int dump_completed(DumpState *s)
	{
	dump_cleanup(s);
	return 0;
	}

	static int get_next_block(DumpState s, GuestPhysBlock block)
	{
	while (1) {
	block = QTAILQ_NEXT(block, next);
	if (!block) {
	/* no more block */
	return 1;
	}

	s->start = 0;
	s->next_block = block;
	if (s->has_filter) {
	if (block->target_start >= s->begin + s->length \|\|
	block->target_end <= s->begin) {
	/* This block is out of the range */
	continue;
	}

	if (s->begin > block->target_start) {
	s->start = s->begin - block->target_start;
	}
	}

	return 0;
	}
	}

	/* write all memory to vmcore */
	static int dump_iterate(DumpState *s)
	{
	GuestPhysBlock *block;
	int64_t size;
	int ret;

	while (1) {
	block = s->next_block;

	size = block->target_end - block->target_start;
	if (s->has_filter) {
	size -= s->start;
	if (s->begin + s->length < block->target_end) {
	size -= block->target_end - (s->begin + s->length);
	}
	}
	ret = write_memory(s, block, s->start, size);
	if (ret == -1) {
	return ret;
	}

	ret = get_next_block(s, block);
	if (ret == 1) {
	dump_completed(s);
	return 0;
	}
	}
	}

	static int create_vmcore(DumpState *s)
	{
	int ret;

	ret = dump_begin(s);
	if (ret < 0) {
	return -1;
	}

	ret = dump_iterate(s);
	if (ret < 0) {
	return -1;
	}

	return 0;
	}

	static ram_addr_t get_start_block(DumpState *s)
	{
	GuestPhysBlock *block;

	if (!s->has_filter) {
	s->next_block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
	return 0;
	}

	QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
	if (block->target_start >= s->begin + s->length \|\|
	block->target_end <= s->begin) {
	/* This block is out of the range */
	continue;
	}

	s->next_block = block;
	if (s->begin > block->target_start) {
	s->start = s->begin - block->target_start;
	} else {
	s->start = 0;
	}
	return s->start;
	}

	return -1;
	}

	static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
	int64_t begin, int64_t length, Error **errp)
	{
	CPUState *cpu;
	int nr_cpus;
	Error *err = NULL;
	int ret;

	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->errp = errp;
	s->fd = fd;
	s->has_filter = has_filter;
	s->begin = begin;
	s->length = length;

	guest_phys_blocks_init(&s->guest_phys_blocks);
	guest_phys_blocks_append(&s->guest_phys_blocks);

	s->start = get_start_block(s);
	if (s->start == -1) {
	error_set(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_set(errp, QERR_UNSUPPORTED);
	goto cleanup;
	}

	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_set(errp, QERR_UNSUPPORTED);
	goto cleanup;
	}

	/* get memory mapping */
	memory_mapping_list_init(&s->list);
	if (paging) {
	qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, &err);
	if (err != NULL) {
	error_propagate(errp, err);
	goto cleanup;
	}
	} else {
	qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
	}

	if (s->has_filter) {
	memory_mapping_filter(&s->list, s->begin, s->length);
	}

	/*
	* calculate phdr_num
	*
	* the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
	*/
	s->phdr_num = 1; /* PT_NOTE */
	if (s->list.num < UINT16_MAX - 2) {
	s->phdr_num += s->list.num;
	s->have_section = false;
	} else {
	s->have_section = true;
	s->phdr_num = PN_XNUM;
	s->sh_info = 1; /* PT_NOTE */

	/* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
	if (s->list.num <= UINT32_MAX - 1) {
	s->sh_info += s->list.num;
	} else {
	s->sh_info = UINT32_MAX;
	}
	}

	if (s->dump_info.d_class == ELFCLASS64) {
	if (s->have_section) {
	s->memory_offset = sizeof(Elf64_Ehdr) +
	sizeof(Elf64_Phdr) * s->sh_info +
	sizeof(Elf64_Shdr) + s->note_size;
	} else {
	s->memory_offset = sizeof(Elf64_Ehdr) +
	sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;
	}
	} else {
	if (s->have_section) {
	s->memory_offset = sizeof(Elf32_Ehdr) +
	sizeof(Elf32_Phdr) * s->sh_info +
	sizeof(Elf32_Shdr) + s->note_size;
	} else {
	s->memory_offset = sizeof(Elf32_Ehdr) +
	sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;
	}
	}

	return 0;

	cleanup:
	guest_phys_blocks_free(&s->guest_phys_blocks);

	if (s->resume) {
	vm_start();
	}

	return -1;
	}

	void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
	int64_t begin, bool has_length, int64_t length,
	Error **errp)
	{
	const char *p;
	int fd = -1;
	DumpState *s;
	int ret;

	if (has_begin && !has_length) {
	error_set(errp, QERR_MISSING_PARAMETER, "length");
	return;
	}
	if (!has_begin && has_length) {
	error_set(errp, QERR_MISSING_PARAMETER, "begin");
	return;
	}

	#if !defined(WIN32)
	if (strstart(file, "fd:", &p)) {
	fd = monitor_get_fd(cur_mon, p, errp);
	if (fd == -1) {
	return;
	}
	}
	#endif

	if (strstart(file, "file:", &p)) {
	fd = qemu_open(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_set(errp, QERR_INVALID_PARAMETER, "protocol");
	return;
	}

	s = g_malloc0(sizeof(DumpState));

	ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
	if (ret < 0) {
	g_free(s);
	return;
	}

	if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
	error_set(errp, QERR_IO_ERROR);
	}

	g_free(s);
	}