diff options
Diffstat (limited to 'migration/vmstate.c')
| -rw-r--r-- | migration/vmstate.c | 34 |
1 files changed, 26 insertions, 8 deletions
diff --git a/migration/vmstate.c b/migration/vmstate.c index 4cde30bf2d..1cf9e45b85 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -26,6 +26,30 @@ static int vmstate_subsection_save(QEMUFile *f, const VMStateDescription *vmsd, static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription *vmsd, void *opaque); +/* Whether this field should exist for either save or load the VM? */ +static bool +vmstate_field_exists(const VMStateDescription *vmsd, const VMStateField *field, + void *opaque, int version_id) +{ + bool result; + + if (field->field_exists) { + /* If there's the function checker, that's the solo truth */ + result = field->field_exists(opaque, version_id); + trace_vmstate_field_exists(vmsd->name, field->name, field->version_id, + version_id, result); + } else { + /* + * Otherwise, we only save/load if field version is same or older. + * For example, when loading from an old binary with old version, + * we ignore new fields with newer version_ids. + */ + result = field->version_id <= version_id; + } + + return result; +} + static int vmstate_n_elems(void *opaque, const VMStateField *field) { int n_elems = 1; @@ -105,10 +129,7 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, } while (field->name) { trace_vmstate_load_state_field(vmsd->name, field->name); - if ((field->field_exists && - field->field_exists(opaque, version_id)) || - (!field->field_exists && - field->version_id <= version_id)) { + if (vmstate_field_exists(vmsd, field, opaque, version_id)) { void *first_elem = opaque + field->offset; int i, n_elems = vmstate_n_elems(opaque, field); int size = vmstate_size(opaque, field); @@ -349,10 +370,7 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, } while (field->name) { - if ((field->field_exists && - field->field_exists(opaque, version_id)) || - (!field->field_exists && - field->version_id <= version_id)) { + if (vmstate_field_exists(vmsd, field, opaque, version_id)) { void *first_elem = opaque + field->offset; int i, n_elems = vmstate_n_elems(opaque, field); int size = vmstate_size(opaque, field); |