diff options
| -rw-r--r-- | migration/vmstate.c | 33 | ||||
| -rwxr-xr-x | scripts/analyze-migration.py | 26 |
2 files changed, 50 insertions, 9 deletions
diff --git a/migration/vmstate.c b/migration/vmstate.c index 52704c822c..82bd005a83 100644 --- a/migration/vmstate.c +++ b/migration/vmstate.c @@ -425,15 +425,19 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, int size = vmstate_size(opaque, field); uint64_t old_offset, written_bytes; JSONWriter *vmdesc_loop = vmdesc; + bool is_prev_null = false; trace_vmstate_save_state_loop(vmsd->name, field->name, n_elems); if (field->flags & VMS_POINTER) { first_elem = *(void **)first_elem; assert(first_elem || !n_elems || !size); } + for (i = 0; i < n_elems; i++) { void *curr_elem = first_elem + size * i; const VMStateField *inner_field; + bool is_null; + int max_elems = n_elems - i; old_offset = qemu_file_transferred(f); if (field->flags & VMS_ARRAY_OF_POINTER) { @@ -448,12 +452,39 @@ int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd, * not follow. */ inner_field = vmsd_create_fake_nullptr_field(field); + is_null = true; } else { inner_field = field; + is_null = false; + } + + /* + * Due to the fake nullptr handling above, if there's mixed + * null/non-null data, it doesn't make sense to emit a + * compressed array representation spanning the entire array + * because the field types will be different (e.g. struct + * vs. nullptr). Search ahead for the next null/non-null element + * and start a new compressed array if found. + */ + if (field->flags & VMS_ARRAY_OF_POINTER && + is_null != is_prev_null) { + + is_prev_null = is_null; + vmdesc_loop = vmdesc; + + for (int j = i + 1; j < n_elems; j++) { + void *elem = *(void **)(first_elem + size * j); + bool elem_is_null = !elem && size; + + if (is_null != elem_is_null) { + max_elems = j - i; + break; + } + } } vmsd_desc_field_start(vmsd, vmdesc_loop, inner_field, - i, n_elems); + i, max_elems); if (inner_field->flags & VMS_STRUCT) { ret = vmstate_save_state(f, inner_field->vmsd, diff --git a/scripts/analyze-migration.py b/scripts/analyze-migration.py index 923f174f1b..8e1fbf4c9d 100755 --- a/scripts/analyze-migration.py +++ b/scripts/analyze-migration.py @@ -502,15 +502,25 @@ class VMSDFieldStruct(VMSDFieldGeneric): field['data'] = reader(field, self.file) field['data'].read() - if 'index' in field: - if field['name'] not in self.data: - self.data[field['name']] = [] - a = self.data[field['name']] - if len(a) != int(field['index']): - raise Exception("internal index of data field unmatched (%d/%d)" % (len(a), int(field['index']))) - a.append(field['data']) + fname = field['name'] + fdata = field['data'] + + # The field could be: + # i) a single data entry, e.g. uint64 + # ii) an array, indicated by it containing the 'index' key + # + # However, the overall data after parsing the whole + # stream, could be a mix of arrays and single data fields, + # all sharing the same field name due to how QEMU breaks + # up arrays with NULL pointers into multiple compressed + # array segments. + if fname not in self.data: + self.data[fname] = fdata + elif type(self.data[fname]) == list: + self.data[fname].append(fdata) else: - self.data[field['name']] = field['data'] + tmp = self.data[fname] + self.data[fname] = [tmp, fdata] if 'subsections' in self.desc['struct']: for subsection in self.desc['struct']['subsections']: |