1a7ae8355SStefano Stabellini= Save Devices = 2a7ae8355SStefano Stabellini 3a7ae8355SStefano StabelliniQEMU has code to load/save the state of the guest that it is running. 4a7ae8355SStefano StabelliniThese are two complementary operations. Saving the state just does 5a7ae8355SStefano Stabellinithat, saves the state for each device that the guest is running. 6a7ae8355SStefano Stabellini 7a7ae8355SStefano StabelliniThese operations are normally used with migration (see migration.txt), 8a7ae8355SStefano Stabellinihowever it is also possible to save the state of all devices to file, 9a7ae8355SStefano Stabelliniwithout saving the RAM or the block devices of the VM. 10a7ae8355SStefano Stabellini 11*1ef1cee7SMarkus ArmbrusterThe save operation is available as QMP command xen-save-devices-state. 12a7ae8355SStefano Stabellini 13a7ae8355SStefano Stabellini 14a7ae8355SStefano StabelliniThe binary format used in the file is the following: 15a7ae8355SStefano Stabellini 16a7ae8355SStefano Stabellini 17a7ae8355SStefano Stabellini------------------------------------------- 18a7ae8355SStefano Stabellini 19a7ae8355SStefano Stabellini32 bit big endian: QEMU_VM_FILE_MAGIC 20a7ae8355SStefano Stabellini32 bit big endian: QEMU_VM_FILE_VERSION 21a7ae8355SStefano Stabellini 22a7ae8355SStefano Stabellinifor_each_device 23a7ae8355SStefano Stabellini{ 24a7ae8355SStefano Stabellini 8 bit: QEMU_VM_SECTION_FULL 25a7ae8355SStefano Stabellini 32 bit big endian: section_id 26a7ae8355SStefano Stabellini 8 bit: idstr (ID string) length 27a7ae8355SStefano Stabellini string: idstr (ID string) 28a7ae8355SStefano Stabellini 32 bit big endian: instance_id 29a7ae8355SStefano Stabellini 32 bit big endian: version_id 30a7ae8355SStefano Stabellini buffer: device specific data 31a7ae8355SStefano Stabellini} 32a7ae8355SStefano Stabellini 33a7ae8355SStefano Stabellini8 bit: QEMU_VM_EOF 34