1*a7ae8355SStefano Stabellini= Save Devices = 2*a7ae8355SStefano Stabellini 3*a7ae8355SStefano StabelliniQEMU has code to load/save the state of the guest that it is running. 4*a7ae8355SStefano StabelliniThese are two complementary operations. Saving the state just does 5*a7ae8355SStefano Stabellinithat, saves the state for each device that the guest is running. 6*a7ae8355SStefano Stabellini 7*a7ae8355SStefano StabelliniThese operations are normally used with migration (see migration.txt), 8*a7ae8355SStefano Stabellinihowever it is also possible to save the state of all devices to file, 9*a7ae8355SStefano Stabelliniwithout saving the RAM or the block devices of the VM. 10*a7ae8355SStefano Stabellini 11*a7ae8355SStefano StabelliniThis operation is called "xen-save-devices-state" (see 12*a7ae8355SStefano StabelliniQMP/qmp-commands.txt) 13*a7ae8355SStefano Stabellini 14*a7ae8355SStefano Stabellini 15*a7ae8355SStefano StabelliniThe binary format used in the file is the following: 16*a7ae8355SStefano Stabellini 17*a7ae8355SStefano Stabellini 18*a7ae8355SStefano Stabellini------------------------------------------- 19*a7ae8355SStefano Stabellini 20*a7ae8355SStefano Stabellini32 bit big endian: QEMU_VM_FILE_MAGIC 21*a7ae8355SStefano Stabellini32 bit big endian: QEMU_VM_FILE_VERSION 22*a7ae8355SStefano Stabellini 23*a7ae8355SStefano Stabellinifor_each_device 24*a7ae8355SStefano Stabellini{ 25*a7ae8355SStefano Stabellini 8 bit: QEMU_VM_SECTION_FULL 26*a7ae8355SStefano Stabellini 32 bit big endian: section_id 27*a7ae8355SStefano Stabellini 8 bit: idstr (ID string) length 28*a7ae8355SStefano Stabellini string: idstr (ID string) 29*a7ae8355SStefano Stabellini 32 bit big endian: instance_id 30*a7ae8355SStefano Stabellini 32 bit big endian: version_id 31*a7ae8355SStefano Stabellini buffer: device specific data 32*a7ae8355SStefano Stabellini} 33*a7ae8355SStefano Stabellini 34*a7ae8355SStefano Stabellini8 bit: QEMU_VM_EOF 35