analyze-migration.py (20729B)
1#!/usr/bin/env python3 2# 3# Migration Stream Analyzer 4# 5# Copyright (c) 2015 Alexander Graf <agraf@suse.de> 6# 7# This library is free software; you can redistribute it and/or 8# modify it under the terms of the GNU Lesser General Public 9# License as published by the Free Software Foundation; either 10# version 2.1 of the License, or (at your option) any later version. 11# 12# This library is distributed in the hope that it will be useful, 13# but WITHOUT ANY WARRANTY; without even the implied warranty of 14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15# Lesser General Public License for more details. 16# 17# You should have received a copy of the GNU Lesser General Public 18# License along with this library; if not, see <http://www.gnu.org/licenses/>. 19 20import json 21import os 22import argparse 23import collections 24import struct 25import sys 26 27 28def mkdir_p(path): 29 try: 30 os.makedirs(path) 31 except OSError: 32 pass 33 34 35class MigrationFile(object): 36 def __init__(self, filename): 37 self.filename = filename 38 self.file = open(self.filename, "rb") 39 40 def read64(self): 41 return int.from_bytes(self.file.read(8), byteorder='big', signed=True) 42 43 def read32(self): 44 return int.from_bytes(self.file.read(4), byteorder='big', signed=True) 45 46 def read16(self): 47 return int.from_bytes(self.file.read(2), byteorder='big', signed=True) 48 49 def read8(self): 50 return int.from_bytes(self.file.read(1), byteorder='big', signed=True) 51 52 def readstr(self, len = None): 53 return self.readvar(len).decode('utf-8') 54 55 def readvar(self, size = None): 56 if size is None: 57 size = self.read8() 58 if size == 0: 59 return "" 60 value = self.file.read(size) 61 if len(value) != size: 62 raise Exception("Unexpected end of %s at 0x%x" % (self.filename, self.file.tell())) 63 return value 64 65 def tell(self): 66 return self.file.tell() 67 68 # The VMSD description is at the end of the file, after EOF. Look for 69 # the last NULL byte, then for the beginning brace of JSON. 70 def read_migration_debug_json(self): 71 QEMU_VM_VMDESCRIPTION = 0x06 72 73 # Remember the offset in the file when we started 74 entrypos = self.file.tell() 75 76 # Read the last 10MB 77 self.file.seek(0, os.SEEK_END) 78 endpos = self.file.tell() 79 self.file.seek(max(-endpos, -10 * 1024 * 1024), os.SEEK_END) 80 datapos = self.file.tell() 81 data = self.file.read() 82 # The full file read closed the file as well, reopen it 83 self.file = open(self.filename, "rb") 84 85 # Find the last NULL byte, then the first brace after that. This should 86 # be the beginning of our JSON data. 87 nulpos = data.rfind(b'\0') 88 jsonpos = data.find(b'{', nulpos) 89 90 # Check backwards from there and see whether we guessed right 91 self.file.seek(datapos + jsonpos - 5, 0) 92 if self.read8() != QEMU_VM_VMDESCRIPTION: 93 raise Exception("No Debug Migration device found") 94 95 jsonlen = self.read32() 96 97 # Seek back to where we were at the beginning 98 self.file.seek(entrypos, 0) 99 100 # explicit decode() needed for Python 3.5 compatibility 101 return data[jsonpos:jsonpos + jsonlen].decode("utf-8") 102 103 def close(self): 104 self.file.close() 105 106class RamSection(object): 107 RAM_SAVE_FLAG_COMPRESS = 0x02 108 RAM_SAVE_FLAG_MEM_SIZE = 0x04 109 RAM_SAVE_FLAG_PAGE = 0x08 110 RAM_SAVE_FLAG_EOS = 0x10 111 RAM_SAVE_FLAG_CONTINUE = 0x20 112 RAM_SAVE_FLAG_XBZRLE = 0x40 113 RAM_SAVE_FLAG_HOOK = 0x80 114 115 def __init__(self, file, version_id, ramargs, section_key): 116 if version_id != 4: 117 raise Exception("Unknown RAM version %d" % version_id) 118 119 self.file = file 120 self.section_key = section_key 121 self.TARGET_PAGE_SIZE = ramargs['page_size'] 122 self.dump_memory = ramargs['dump_memory'] 123 self.write_memory = ramargs['write_memory'] 124 self.sizeinfo = collections.OrderedDict() 125 self.data = collections.OrderedDict() 126 self.data['section sizes'] = self.sizeinfo 127 self.name = '' 128 if self.write_memory: 129 self.files = { } 130 if self.dump_memory: 131 self.memory = collections.OrderedDict() 132 self.data['memory'] = self.memory 133 134 def __repr__(self): 135 return self.data.__repr__() 136 137 def __str__(self): 138 return self.data.__str__() 139 140 def getDict(self): 141 return self.data 142 143 def read(self): 144 # Read all RAM sections 145 while True: 146 addr = self.file.read64() 147 flags = addr & (self.TARGET_PAGE_SIZE - 1) 148 addr &= ~(self.TARGET_PAGE_SIZE - 1) 149 150 if flags & self.RAM_SAVE_FLAG_MEM_SIZE: 151 while True: 152 namelen = self.file.read8() 153 # We assume that no RAM chunk is big enough to ever 154 # hit the first byte of the address, so when we see 155 # a zero here we know it has to be an address, not the 156 # length of the next block. 157 if namelen == 0: 158 self.file.file.seek(-1, 1) 159 break 160 self.name = self.file.readstr(len = namelen) 161 len = self.file.read64() 162 self.sizeinfo[self.name] = '0x%016x' % len 163 if self.write_memory: 164 print(self.name) 165 mkdir_p('./' + os.path.dirname(self.name)) 166 f = open('./' + self.name, "wb") 167 f.truncate(0) 168 f.truncate(len) 169 self.files[self.name] = f 170 flags &= ~self.RAM_SAVE_FLAG_MEM_SIZE 171 172 if flags & self.RAM_SAVE_FLAG_COMPRESS: 173 if flags & self.RAM_SAVE_FLAG_CONTINUE: 174 flags &= ~self.RAM_SAVE_FLAG_CONTINUE 175 else: 176 self.name = self.file.readstr() 177 fill_char = self.file.read8() 178 # The page in question is filled with fill_char now 179 if self.write_memory and fill_char != 0: 180 self.files[self.name].seek(addr, os.SEEK_SET) 181 self.files[self.name].write(chr(fill_char) * self.TARGET_PAGE_SIZE) 182 if self.dump_memory: 183 self.memory['%s (0x%016x)' % (self.name, addr)] = 'Filled with 0x%02x' % fill_char 184 flags &= ~self.RAM_SAVE_FLAG_COMPRESS 185 elif flags & self.RAM_SAVE_FLAG_PAGE: 186 if flags & self.RAM_SAVE_FLAG_CONTINUE: 187 flags &= ~self.RAM_SAVE_FLAG_CONTINUE 188 else: 189 self.name = self.file.readstr() 190 191 if self.write_memory or self.dump_memory: 192 data = self.file.readvar(size = self.TARGET_PAGE_SIZE) 193 else: # Just skip RAM data 194 self.file.file.seek(self.TARGET_PAGE_SIZE, 1) 195 196 if self.write_memory: 197 self.files[self.name].seek(addr, os.SEEK_SET) 198 self.files[self.name].write(data) 199 if self.dump_memory: 200 hexdata = " ".join("{0:02x}".format(ord(c)) for c in data) 201 self.memory['%s (0x%016x)' % (self.name, addr)] = hexdata 202 203 flags &= ~self.RAM_SAVE_FLAG_PAGE 204 elif flags & self.RAM_SAVE_FLAG_XBZRLE: 205 raise Exception("XBZRLE RAM compression is not supported yet") 206 elif flags & self.RAM_SAVE_FLAG_HOOK: 207 raise Exception("RAM hooks don't make sense with files") 208 209 # End of RAM section 210 if flags & self.RAM_SAVE_FLAG_EOS: 211 break 212 213 if flags != 0: 214 raise Exception("Unknown RAM flags: %x" % flags) 215 216 def __del__(self): 217 if self.write_memory: 218 for key in self.files: 219 self.files[key].close() 220 221 222class HTABSection(object): 223 HASH_PTE_SIZE_64 = 16 224 225 def __init__(self, file, version_id, device, section_key): 226 if version_id != 1: 227 raise Exception("Unknown HTAB version %d" % version_id) 228 229 self.file = file 230 self.section_key = section_key 231 232 def read(self): 233 234 header = self.file.read32() 235 236 if (header == -1): 237 # "no HPT" encoding 238 return 239 240 if (header > 0): 241 # First section, just the hash shift 242 return 243 244 # Read until end marker 245 while True: 246 index = self.file.read32() 247 n_valid = self.file.read16() 248 n_invalid = self.file.read16() 249 250 if index == 0 and n_valid == 0 and n_invalid == 0: 251 break 252 253 self.file.readvar(n_valid * self.HASH_PTE_SIZE_64) 254 255 def getDict(self): 256 return "" 257 258 259class ConfigurationSection(object): 260 def __init__(self, file): 261 self.file = file 262 263 def read(self): 264 name_len = self.file.read32() 265 name = self.file.readstr(len = name_len) 266 267class VMSDFieldGeneric(object): 268 def __init__(self, desc, file): 269 self.file = file 270 self.desc = desc 271 self.data = "" 272 273 def __repr__(self): 274 return str(self.__str__()) 275 276 def __str__(self): 277 return " ".join("{0:02x}".format(c) for c in self.data) 278 279 def getDict(self): 280 return self.__str__() 281 282 def read(self): 283 size = int(self.desc['size']) 284 self.data = self.file.readvar(size) 285 return self.data 286 287class VMSDFieldInt(VMSDFieldGeneric): 288 def __init__(self, desc, file): 289 super(VMSDFieldInt, self).__init__(desc, file) 290 self.size = int(desc['size']) 291 self.format = '0x%%0%dx' % (self.size * 2) 292 self.sdtype = '>i%d' % self.size 293 self.udtype = '>u%d' % self.size 294 295 def __repr__(self): 296 if self.data < 0: 297 return ('%s (%d)' % ((self.format % self.udata), self.data)) 298 else: 299 return self.format % self.data 300 301 def __str__(self): 302 return self.__repr__() 303 304 def getDict(self): 305 return self.__str__() 306 307 def read(self): 308 super(VMSDFieldInt, self).read() 309 self.sdata = int.from_bytes(self.data, byteorder='big', signed=True) 310 self.udata = int.from_bytes(self.data, byteorder='big', signed=False) 311 self.data = self.sdata 312 return self.data 313 314class VMSDFieldUInt(VMSDFieldInt): 315 def __init__(self, desc, file): 316 super(VMSDFieldUInt, self).__init__(desc, file) 317 318 def read(self): 319 super(VMSDFieldUInt, self).read() 320 self.data = self.udata 321 return self.data 322 323class VMSDFieldIntLE(VMSDFieldInt): 324 def __init__(self, desc, file): 325 super(VMSDFieldIntLE, self).__init__(desc, file) 326 self.dtype = '<i%d' % self.size 327 328class VMSDFieldBool(VMSDFieldGeneric): 329 def __init__(self, desc, file): 330 super(VMSDFieldBool, self).__init__(desc, file) 331 332 def __repr__(self): 333 return self.data.__repr__() 334 335 def __str__(self): 336 return self.data.__str__() 337 338 def getDict(self): 339 return self.data 340 341 def read(self): 342 super(VMSDFieldBool, self).read() 343 if self.data[0] == 0: 344 self.data = False 345 else: 346 self.data = True 347 return self.data 348 349class VMSDFieldStruct(VMSDFieldGeneric): 350 QEMU_VM_SUBSECTION = 0x05 351 352 def __init__(self, desc, file): 353 super(VMSDFieldStruct, self).__init__(desc, file) 354 self.data = collections.OrderedDict() 355 356 # When we see compressed array elements, unfold them here 357 new_fields = [] 358 for field in self.desc['struct']['fields']: 359 if not 'array_len' in field: 360 new_fields.append(field) 361 continue 362 array_len = field.pop('array_len') 363 field['index'] = 0 364 new_fields.append(field) 365 for i in range(1, array_len): 366 c = field.copy() 367 c['index'] = i 368 new_fields.append(c) 369 370 self.desc['struct']['fields'] = new_fields 371 372 def __repr__(self): 373 return self.data.__repr__() 374 375 def __str__(self): 376 return self.data.__str__() 377 378 def read(self): 379 for field in self.desc['struct']['fields']: 380 try: 381 reader = vmsd_field_readers[field['type']] 382 except: 383 reader = VMSDFieldGeneric 384 385 field['data'] = reader(field, self.file) 386 field['data'].read() 387 388 if 'index' in field: 389 if field['name'] not in self.data: 390 self.data[field['name']] = [] 391 a = self.data[field['name']] 392 if len(a) != int(field['index']): 393 raise Exception("internal index of data field unmatched (%d/%d)" % (len(a), int(field['index']))) 394 a.append(field['data']) 395 else: 396 self.data[field['name']] = field['data'] 397 398 if 'subsections' in self.desc['struct']: 399 for subsection in self.desc['struct']['subsections']: 400 if self.file.read8() != self.QEMU_VM_SUBSECTION: 401 raise Exception("Subsection %s not found at offset %x" % ( subsection['vmsd_name'], self.file.tell())) 402 name = self.file.readstr() 403 version_id = self.file.read32() 404 self.data[name] = VMSDSection(self.file, version_id, subsection, (name, 0)) 405 self.data[name].read() 406 407 def getDictItem(self, value): 408 # Strings would fall into the array category, treat 409 # them specially 410 if value.__class__ is ''.__class__: 411 return value 412 413 try: 414 return self.getDictOrderedDict(value) 415 except: 416 try: 417 return self.getDictArray(value) 418 except: 419 try: 420 return value.getDict() 421 except: 422 return value 423 424 def getDictArray(self, array): 425 r = [] 426 for value in array: 427 r.append(self.getDictItem(value)) 428 return r 429 430 def getDictOrderedDict(self, dict): 431 r = collections.OrderedDict() 432 for (key, value) in dict.items(): 433 r[key] = self.getDictItem(value) 434 return r 435 436 def getDict(self): 437 return self.getDictOrderedDict(self.data) 438 439vmsd_field_readers = { 440 "bool" : VMSDFieldBool, 441 "int8" : VMSDFieldInt, 442 "int16" : VMSDFieldInt, 443 "int32" : VMSDFieldInt, 444 "int32 equal" : VMSDFieldInt, 445 "int32 le" : VMSDFieldIntLE, 446 "int64" : VMSDFieldInt, 447 "uint8" : VMSDFieldUInt, 448 "uint16" : VMSDFieldUInt, 449 "uint32" : VMSDFieldUInt, 450 "uint32 equal" : VMSDFieldUInt, 451 "uint64" : VMSDFieldUInt, 452 "int64 equal" : VMSDFieldInt, 453 "uint8 equal" : VMSDFieldInt, 454 "uint16 equal" : VMSDFieldInt, 455 "float64" : VMSDFieldGeneric, 456 "timer" : VMSDFieldGeneric, 457 "buffer" : VMSDFieldGeneric, 458 "unused_buffer" : VMSDFieldGeneric, 459 "bitmap" : VMSDFieldGeneric, 460 "struct" : VMSDFieldStruct, 461 "unknown" : VMSDFieldGeneric, 462} 463 464class VMSDSection(VMSDFieldStruct): 465 def __init__(self, file, version_id, device, section_key): 466 self.file = file 467 self.data = "" 468 self.vmsd_name = "" 469 self.section_key = section_key 470 desc = device 471 if 'vmsd_name' in device: 472 self.vmsd_name = device['vmsd_name'] 473 474 # A section really is nothing but a FieldStruct :) 475 super(VMSDSection, self).__init__({ 'struct' : desc }, file) 476 477############################################################################### 478 479class MigrationDump(object): 480 QEMU_VM_FILE_MAGIC = 0x5145564d 481 QEMU_VM_FILE_VERSION = 0x00000003 482 QEMU_VM_EOF = 0x00 483 QEMU_VM_SECTION_START = 0x01 484 QEMU_VM_SECTION_PART = 0x02 485 QEMU_VM_SECTION_END = 0x03 486 QEMU_VM_SECTION_FULL = 0x04 487 QEMU_VM_SUBSECTION = 0x05 488 QEMU_VM_VMDESCRIPTION = 0x06 489 QEMU_VM_CONFIGURATION = 0x07 490 QEMU_VM_SECTION_FOOTER= 0x7e 491 492 def __init__(self, filename): 493 self.section_classes = { ( 'ram', 0 ) : [ RamSection, None ], 494 ( 'spapr/htab', 0) : ( HTABSection, None ) } 495 self.filename = filename 496 self.vmsd_desc = None 497 498 def read(self, desc_only = False, dump_memory = False, write_memory = False): 499 # Read in the whole file 500 file = MigrationFile(self.filename) 501 502 # File magic 503 data = file.read32() 504 if data != self.QEMU_VM_FILE_MAGIC: 505 raise Exception("Invalid file magic %x" % data) 506 507 # Version (has to be v3) 508 data = file.read32() 509 if data != self.QEMU_VM_FILE_VERSION: 510 raise Exception("Invalid version number %d" % data) 511 512 self.load_vmsd_json(file) 513 514 # Read sections 515 self.sections = collections.OrderedDict() 516 517 if desc_only: 518 return 519 520 ramargs = {} 521 ramargs['page_size'] = self.vmsd_desc['page_size'] 522 ramargs['dump_memory'] = dump_memory 523 ramargs['write_memory'] = write_memory 524 self.section_classes[('ram',0)][1] = ramargs 525 526 while True: 527 section_type = file.read8() 528 if section_type == self.QEMU_VM_EOF: 529 break 530 elif section_type == self.QEMU_VM_CONFIGURATION: 531 section = ConfigurationSection(file) 532 section.read() 533 elif section_type == self.QEMU_VM_SECTION_START or section_type == self.QEMU_VM_SECTION_FULL: 534 section_id = file.read32() 535 name = file.readstr() 536 instance_id = file.read32() 537 version_id = file.read32() 538 section_key = (name, instance_id) 539 classdesc = self.section_classes[section_key] 540 section = classdesc[0](file, version_id, classdesc[1], section_key) 541 self.sections[section_id] = section 542 section.read() 543 elif section_type == self.QEMU_VM_SECTION_PART or section_type == self.QEMU_VM_SECTION_END: 544 section_id = file.read32() 545 self.sections[section_id].read() 546 elif section_type == self.QEMU_VM_SECTION_FOOTER: 547 read_section_id = file.read32() 548 if read_section_id != section_id: 549 raise Exception("Mismatched section footer: %x vs %x" % (read_section_id, section_id)) 550 else: 551 raise Exception("Unknown section type: %d" % section_type) 552 file.close() 553 554 def load_vmsd_json(self, file): 555 vmsd_json = file.read_migration_debug_json() 556 self.vmsd_desc = json.loads(vmsd_json, object_pairs_hook=collections.OrderedDict) 557 for device in self.vmsd_desc['devices']: 558 key = (device['name'], device['instance_id']) 559 value = ( VMSDSection, device ) 560 self.section_classes[key] = value 561 562 def getDict(self): 563 r = collections.OrderedDict() 564 for (key, value) in self.sections.items(): 565 key = "%s (%d)" % ( value.section_key[0], key ) 566 r[key] = value.getDict() 567 return r 568 569############################################################################### 570 571class JSONEncoder(json.JSONEncoder): 572 def default(self, o): 573 if isinstance(o, VMSDFieldGeneric): 574 return str(o) 575 return json.JSONEncoder.default(self, o) 576 577parser = argparse.ArgumentParser() 578parser.add_argument("-f", "--file", help='migration dump to read from', required=True) 579parser.add_argument("-m", "--memory", help='dump RAM contents as well', action='store_true') 580parser.add_argument("-d", "--dump", help='what to dump ("state" or "desc")', default='state') 581parser.add_argument("-x", "--extract", help='extract contents into individual files', action='store_true') 582args = parser.parse_args() 583 584jsonenc = JSONEncoder(indent=4, separators=(',', ': ')) 585 586if args.extract: 587 dump = MigrationDump(args.file) 588 589 dump.read(desc_only = True) 590 print("desc.json") 591 f = open("desc.json", "wb") 592 f.truncate() 593 f.write(jsonenc.encode(dump.vmsd_desc)) 594 f.close() 595 596 dump.read(write_memory = True) 597 dict = dump.getDict() 598 print("state.json") 599 f = open("state.json", "wb") 600 f.truncate() 601 f.write(jsonenc.encode(dict)) 602 f.close() 603elif args.dump == "state": 604 dump = MigrationDump(args.file) 605 dump.read(dump_memory = args.memory) 606 dict = dump.getDict() 607 print(jsonenc.encode(dict)) 608elif args.dump == "desc": 609 dump = MigrationDump(args.file) 610 dump.read(desc_only = True) 611 print(jsonenc.encode(dump.vmsd_desc)) 612else: 613 raise Exception("Please specify either -x, -d state or -d dump")