diff options
Diffstat (limited to 'scripts/analyze-migration.py')
| -rwxr-xr-x | scripts/analyze-migration.py | 151 |
1 files changed, 113 insertions, 38 deletions
diff --git a/scripts/analyze-migration.py b/scripts/analyze-migration.py index 8a254a5..67631ac 100755 --- a/scripts/analyze-migration.py +++ b/scripts/analyze-migration.py @@ -65,6 +65,9 @@ class MigrationFile(object): def tell(self): return self.file.tell() + def seek(self, a, b): + return self.file.seek(a, b) + # The VMSD description is at the end of the file, after EOF. Look for # the last NULL byte, then for the beginning brace of JSON. def read_migration_debug_json(self): @@ -272,11 +275,24 @@ class S390StorageAttributes(object): self.section_key = section_key def read(self): + pos = 0 while True: addr_flags = self.file.read64() flags = addr_flags & 0xfff - if (flags & (self.STATTR_FLAG_DONE | self.STATTR_FLAG_EOS)): + + if flags & self.STATTR_FLAG_DONE: + pos = self.file.tell() + continue + elif flags & self.STATTR_FLAG_EOS: return + else: + # No EOS came after DONE, that's OK, but rewind the + # stream because this is not our data. + if pos: + self.file.seek(pos, os.SEEK_SET) + return + raise Exception("Unknown flags %x", flags) + if (flags & self.STATTR_FLAG_ERROR): raise Exception("Error in migration stream") count = self.file.read64() @@ -401,6 +417,28 @@ class VMSDFieldIntLE(VMSDFieldInt): super(VMSDFieldIntLE, self).__init__(desc, file) self.dtype = '<i%d' % self.size +class VMSDFieldNull(VMSDFieldGeneric): + NULL_PTR_MARKER = b'0' + + def __init__(self, desc, file): + super(VMSDFieldNull, self).__init__(desc, file) + + def __repr__(self): + # A NULL pointer is encoded in the stream as a '0' to + # disambiguate from a mere 0x0 value and avoid consumers + # trying to follow the NULL pointer. Displaying '0', 0x30 or + # 0x0 when analyzing the JSON debug stream could become + # confusing, so use an explicit term instead. + return "nullptr" + + def __str__(self): + return self.__repr__() + + def read(self): + super(VMSDFieldNull, self).read() + assert(self.data == self.NULL_PTR_MARKER) + return self.data + class VMSDFieldBool(VMSDFieldGeneric): def __init__(self, desc, file): super(VMSDFieldBool, self).__init__(desc, file) @@ -429,6 +467,9 @@ class VMSDFieldStruct(VMSDFieldGeneric): super(VMSDFieldStruct, self).__init__(desc, file) self.data = collections.OrderedDict() + if 'fields' not in self.desc['struct']: + raise Exception("No fields in struct. VMSD:\n%s" % self.desc) + # When we see compressed array elements, unfold them here new_fields = [] for field in self.desc['struct']['fields']: @@ -461,15 +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']: @@ -477,6 +528,10 @@ class VMSDFieldStruct(VMSDFieldGeneric): raise Exception("Subsection %s not found at offset %x" % ( subsection['vmsd_name'], self.file.tell())) name = self.file.readstr() version_id = self.file.read32() + + if not subsection: + raise Exception("Empty description for subsection: %s" % name) + self.data[name] = VMSDSection(self.file, version_id, subsection, (name, 0)) self.data[name].read() @@ -535,6 +590,7 @@ vmsd_field_readers = { "bitmap" : VMSDFieldGeneric, "struct" : VMSDFieldStruct, "capability": VMSDFieldCap, + "nullptr": VMSDFieldNull, "unknown" : VMSDFieldGeneric, } @@ -564,7 +620,9 @@ class MigrationDump(object): QEMU_VM_SUBSECTION = 0x05 QEMU_VM_VMDESCRIPTION = 0x06 QEMU_VM_CONFIGURATION = 0x07 + QEMU_VM_COMMAND = 0x08 QEMU_VM_SECTION_FOOTER= 0x7e + QEMU_MIG_CMD_SWITCHOVER_START = 0x0b def __init__(self, filename): self.section_classes = { @@ -574,10 +632,13 @@ class MigrationDump(object): } self.filename = filename self.vmsd_desc = None + self.vmsd_json = "" - def read(self, desc_only = False, dump_memory = False, write_memory = False): + def read(self, desc_only = False, dump_memory = False, + write_memory = False): # Read in the whole file file = MigrationFile(self.filename) + self.vmsd_json = file.read_migration_debug_json() # File magic data = file.read32() @@ -626,6 +687,15 @@ class MigrationDump(object): elif section_type == self.QEMU_VM_SECTION_PART or section_type == self.QEMU_VM_SECTION_END: section_id = file.read32() self.sections[section_id].read() + elif section_type == self.QEMU_VM_COMMAND: + command_type = file.read16() + command_data_len = file.read16() + if command_type != self.QEMU_MIG_CMD_SWITCHOVER_START: + raise Exception("Unknown QEMU_VM_COMMAND: %x" % + (command_type)) + if command_data_len != 0: + raise Exception("Invalid SWITCHOVER_START length: %x" % + (command_data_len)) elif section_type == self.QEMU_VM_SECTION_FOOTER: read_section_id = file.read32() if read_section_id != section_id: @@ -635,9 +705,11 @@ class MigrationDump(object): file.close() def load_vmsd_json(self, file): - vmsd_json = file.read_migration_debug_json() - self.vmsd_desc = json.loads(vmsd_json, object_pairs_hook=collections.OrderedDict) + self.vmsd_desc = json.loads(self.vmsd_json, + object_pairs_hook=collections.OrderedDict) for device in self.vmsd_desc['devices']: + if 'fields' not in device: + raise Exception("vmstate for device %s has no fields" % device['name']) key = (device['name'], device['instance_id']) value = ( VMSDSection, device ) self.section_classes[key] = value @@ -666,31 +738,34 @@ args = parser.parse_args() jsonenc = JSONEncoder(indent=4, separators=(',', ': ')) -if args.extract: - dump = MigrationDump(args.file) +if not any([args.extract, args.dump == "state", args.dump == "desc"]): + raise Exception("Please specify either -x, -d state or -d desc") - dump.read(desc_only = True) - print("desc.json") - f = open("desc.json", "w") - f.truncate() - f.write(jsonenc.encode(dump.vmsd_desc)) - f.close() - - dump.read(write_memory = True) - dict = dump.getDict() - print("state.json") - f = open("state.json", "w") - f.truncate() - f.write(jsonenc.encode(dict)) - f.close() -elif args.dump == "state": +try: dump = MigrationDump(args.file) - dump.read(dump_memory = args.memory) - dict = dump.getDict() - print(jsonenc.encode(dict)) -elif args.dump == "desc": - dump = MigrationDump(args.file) - dump.read(desc_only = True) - print(jsonenc.encode(dump.vmsd_desc)) -else: - raise Exception("Please specify either -x, -d state or -d desc") + + if args.extract: + dump.read(desc_only = True) + + print("desc.json") + f = open("desc.json", "w") + f.truncate() + f.write(jsonenc.encode(dump.vmsd_desc)) + f.close() + + dump.read(write_memory = True) + dict = dump.getDict() + print("state.json") + f = open("state.json", "w") + f.truncate() + f.write(jsonenc.encode(dict)) + f.close() + elif args.dump == "state": + dump.read(dump_memory = args.memory) + dict = dump.getDict() + print(jsonenc.encode(dict)) + elif args.dump == "desc": + dump.read(desc_only = True) + print(jsonenc.encode(dump.vmsd_desc)) +except Exception: + raise Exception("Full JSON dump:\n%s", dump.vmsd_json) |