Stefano Stabellini | a7ae835 | 2012-01-25 12:24:51 +0000 | [diff] [blame] | 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 | |
Markus Armbruster | 1ef1cee | 2018-02-11 10:36:06 +0100 | [diff] [blame] | 11 | The save operation is available as QMP command xen-save-devices-state. |
Stefano Stabellini | a7ae835 | 2012-01-25 12:24:51 +0000 | [diff] [blame] | 12 | |
| 13 | |
| 14 | The binary format used in the file is the following: |
| 15 | |
| 16 | |
| 17 | ------------------------------------------- |
| 18 | |
| 19 | 32 bit big endian: QEMU_VM_FILE_MAGIC |
| 20 | 32 bit big endian: QEMU_VM_FILE_VERSION |
| 21 | |
| 22 | for_each_device |
| 23 | { |
| 24 | 8 bit: QEMU_VM_SECTION_FULL |
| 25 | 32 bit big endian: section_id |
| 26 | 8 bit: idstr (ID string) length |
| 27 | string: idstr (ID string) |
| 28 | 32 bit big endian: instance_id |
| 29 | 32 bit big endian: version_id |
| 30 | buffer: device specific data |
| 31 | } |
| 32 | |
| 33 | 8 bit: QEMU_VM_EOF |