docs/xen-save-devices-state.txt

   1 = Save Devices =
   2
   3 QEMU has code to load/save the state of the guest that it is running.
   4 These are two complementary operations.  Saving the state just does
   5 that, saves the state for each device that the guest is running.
   6
   7 These operations are normally used with migration (see migration.txt),
   8 however it is also possible to save the state of all devices to file,
   9 without saving the RAM or the block devices of the VM.
  10
  11 This operation is called "xen-save-devices-state" (see
  12 QMP/qmp-commands.txt)
  13
  14
  15 The binary format used in the file is the following:
  16
  17
  18 -------------------------------------------
  19
  20 32 bit big endian: QEMU_VM_FILE_MAGIC
  21 32 bit big endian: QEMU_VM_FILE_VERSION
  22
  23 for_each_device
  24 {
  25     8 bit:              QEMU_VM_SECTION_FULL
  26     32 bit big endian:  section_id
  27     8 bit:              idstr (ID string) length
  28     string:             idstr (ID string)
  29     32 bit big endian:  instance_id
  30     32 bit big endian:  version_id
  31     buffer:             device specific data
  32 }
  33
  34 8 bit: QEMU_VM_EOF