diff options
Diffstat (limited to 'include/migration/vmstate.h')
| -rw-r--r-- | include/migration/vmstate.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h index df463fd33d..efa0a1150e 100644 --- a/include/migration/vmstate.h +++ b/include/migration/vmstate.h @@ -143,6 +143,11 @@ enum VMStateFlags { * to determine the number of entries in the array. Only valid in * combination with one of VMS_VARRAY*. */ VMS_MULTIPLY_ELEMENTS = 0x4000, + + /* A structure field that is like VMS_STRUCT, but uses + * VMStateField.struct_version_id to tell which version of the + * structure we are referencing to use. */ + VMS_VSTRUCT = 0x8000, }; typedef enum { @@ -167,6 +172,7 @@ struct VMStateField { enum VMStateFlags flags; const VMStateDescription *vmsd; int version_id; + int struct_version_id; bool (*field_exists)(void *opaque, int version_id); }; @@ -248,6 +254,25 @@ extern const VMStateInfo vmstate_info_qtailq; vmstate_offset_array(_state, _field, uint8_t, \ sizeof(typeof_field(_state, _field))) +/* In the macros below, if there is a _version, that means the macro's + * field will be processed only if the version being received is >= + * the _version specified. In general, if you add a new field, you + * would increment the structure's version and put that version + * number into the new field so it would only be processed with the + * new version. + * + * In particular, for VMSTATE_STRUCT() and friends the _version does + * *NOT* pick the version of the sub-structure. It works just as + * specified above. The version of the top-level structure received + * is passed down to all sub-structures. This means that the + * sub-structures must have version that are compatible with all the + * structures that use them. + * + * If you want to specify the version of the sub-structure, use + * VMSTATE_VSTRUCT(), which allows the specific sub-structure version + * to be directly specified. + */ + #define VMSTATE_SINGLE_TEST(_field, _state, _test, _version, _info, _type) { \ .name = (stringify(_field)), \ .version_id = (_version), \ @@ -395,6 +420,17 @@ extern const VMStateInfo vmstate_info_qtailq; .offset = offsetof(_state, _field), \ } +#define VMSTATE_VSTRUCT_TEST(_field, _state, _test, _version, _vmsd, _type, _struct_version) { \ + .name = (stringify(_field)), \ + .version_id = (_version), \ + .struct_version_id = (_struct_version), \ + .field_exists = (_test), \ + .vmsd = &(_vmsd), \ + .size = sizeof(_type), \ + .flags = VMS_VSTRUCT, \ + .offset = vmstate_offset_value(_state, _field, _type), \ +} + #define VMSTATE_STRUCT_TEST(_field, _state, _test, _version, _vmsd, _type) { \ .name = (stringify(_field)), \ .version_id = (_version), \ @@ -712,6 +748,13 @@ extern const VMStateInfo vmstate_info_qtailq; #define VMSTATE_SINGLE(_field, _state, _version, _info, _type) \ VMSTATE_SINGLE_TEST(_field, _state, NULL, _version, _info, _type) +#define VMSTATE_VSTRUCT(_field, _state, _vmsd, _type, _struct_version)\ + VMSTATE_VSTRUCT_TEST(_field, _state, NULL, 0, _vmsd, _type, _struct_version) + +#define VMSTATE_VSTRUCT_V(_field, _state, _version, _vmsd, _type, _struct_version) \ + VMSTATE_VSTRUCT_TEST(_field, _state, NULL, _version, _vmsd, _type, \ + _struct_version) + #define VMSTATE_STRUCT(_field, _state, _version, _vmsd, _type) \ VMSTATE_STRUCT_TEST(_field, _state, NULL, _version, _vmsd, _type) @@ -1000,6 +1043,8 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, void *opaque, int version_id); int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, void *opaque, QJSON *vmdesc); +int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, + void *opaque, QJSON *vmdesc, int version_id); bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque); |