#!/usr/bin/env python3
#
# Migration Stream Analyzer
#
# Copyright (c) 2015 Alexander Graf <agraf@suse.de>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, see <http://www.gnu.org/licenses/>.
import json
import os
import argparse
import collections
import struct
import sys
def mkdir_p(path):
try:
os.makedirs(path)
except OSError:
pass
class MigrationFile(object):
def __init__(self, filename):
self.filename = filename
self.file = open(self.filename, "rb")
def read64(self):
return int.from_bytes(self.file.read(8), byteorder='big', signed=True)
def read32(self):
return int.from_bytes(self.file.read(4), byteorder='big', signed=True)
def read16(self):
return int.from_bytes(self.file.read(2), byteorder='big', signed=True)
def read8(self):
return int.from_bytes(self.file.read(1), byteorder='big', signed=True)
def readstr(self, len = None):
return self.readvar(len).decode('utf-8')
def readvar(self, size = None):
if size is None:
size = self.read8()
if size == 0:
return ""
value = self.file.read(size)
if len(value) != size:
raise Exception("Unexpected end of %s at 0x%x" % (self.filename, self.file.tell()))
return value
def tell(self):
return self.file.tell()
# 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):
QEMU_VM_VMDESCRIPTION = 0x06
# Remember the offset in the file when we started
entrypos = self.file.tell()
# Read the last 10MB
self.file.seek(0, os.SEEK_END)
endpos = self.file.tell()
self.file.seek(max(-endpos, -10 * 1024 * 1024), os.SEEK_END)
datapos = self.file.tell()
data = self.file.read()
# The full file read closed the file as well, reopen it
self.file = open(self.filename, "rb")
# Find the last NULL byte, then the first brace after that. This should
# be the beginning of our JSON data.
nulpos = data.rfind(b'\0')
jsonpos = data.find(b'{', nulpos)
# Check backwards from there and see whether we guessed right
self.file.seek(datapos + jsonpos - 5, 0)
if self.read8() != QEMU_VM_VMDESCRIPTION:
raise Exception("No Debug Migration device found")
jsonlen = self.read32()
# Seek back to where we were at the beginning
self.file.seek(entrypos, 0)
# explicit decode() needed for Python 3.5 compatibility
return data[jsonpos:jsonpos + jsonlen].decode("utf-8")
def close(self):
self.file.close()
class RamSection(object):
RAM_SAVE_FLAG_COMPRESS = 0x02
RAM_SAVE_FLAG_MEM_SIZE = 0x04
RAM_SAVE_FLAG_PAGE = 0x08
RAM_SAVE_FLAG_EOS = 0x10
RAM_SAVE_FLAG_CONTINUE = 0x20
RAM_SAVE_FLAG_XBZRLE = 0x40
RAM_SAVE_FLAG_HOOK = 0x80
def __init__(self, file, version_id, ramargs, section_key):
if version_id != 4:
raise Exception("Unknown RAM version %d" % version_id)
self.file = file
self.section_key = section_key
self.TARGET_PAGE_SIZE = ramargs['page_size']
self.dump_memory = ramargs['dump_memory']
self.write_memory = ramargs['write_memory']
self.sizeinfo = collections.OrderedDict()
self.data = collections.OrderedDict()
self.data['section sizes'] = self.sizeinfo
self.name = ''
if self.write_memory:
self.files = { }
if self.dump_memory:
self.memory = collections.OrderedDict()
self.data['memory'] = self.memory
def __repr__(self):
return self.data.__repr__()
def __str__(self):
return self.data.__str__()
def getDict(self):
return self.data
def read(self):
# Read all RAM sections
while True:
addr = self.file.read64()
flags = addr & (self.TARGET_PAGE_SIZE - 1)
addr &= ~(self.TARGET_PAGE_SIZE - 1)
if flags & self.RAM_SAVE_FLAG_MEM_SIZE:
while True:
namelen = self.file.read8()
# We assume that no RAM chunk is big enough to ever
# hit the first byte of the address, so when we see
# a zero here we know it has to be an address, not the
# length of the next block.
if namelen == 0:
self.file.file.seek(-1, 1)
break
self.name = self.file.readstr(len = namelen)
len = self.file.read64()
self.sizeinfo[self.name] = '0x%016x' % len
if self.write_memory:
print(self.name)
mkdir_p('./' + os.path.dirname(self.name))
f = open('./' + self.name, "wb")
f.truncate(0)
f.truncate(len)
self.files[self.name] = f
flags &= ~self.RAM_SAVE_FLAG_MEM_SIZE
if flags & self.RAM_SAVE_FLAG_COMPRESS:
if flags & self.RAM_SAVE_FLAG_CONTINUE:
flags &= ~self.RAM_SAVE_FLAG_CONTINUE
else:
self.name = self.file.readstr()
fill_char = self.file.read8()
# The page in question is filled with fill_char now
if self.write_memory and fill_char != 0:
self.files[self.name].seek(addr, os.SEEK_SET)
self.files[self.name].write(chr(fill_char) * self.TARGET_PAGE_SIZE)
if self.dump_memory:
self.memory['%s (0x%016x)' % (self.name, addr)] = 'Filled with 0x%02x' % fill_char
flags &= ~self.RAM_SAVE_FLAG_COMPRESS
elif flags & self.RAM_SAVE_FLAG_PAGE:
if flags & self.RAM_SAVE_FLAG_CONTINUE:
flags &= ~self.RAM_SAVE_FLAG_CONTINUE
else:
self.name = self.file.readstr()
if self.write_memory or self.dump_memory:
data = self.file.readvar(size = self.TARGET_PAGE_SIZE)
else: # Just skip RAM data
self.file.file.seek(self.TARGET_PAGE_SIZE, 1)
if self.write_memory:
self.files[self.name].seek(addr, os.SEEK_SET)
self.files[self.name].write(data)
if self.dump_memory:
hexdata = " ".join("{0:02x}".format(ord(c)) for c in data)
self.memory['%s (0x%016x)' % (self.name, addr)] = hexdata
flags &= ~self.RAM_SAVE_FLAG_PAGE
elif flags & self.RAM_SAVE_FLAG_XBZRLE:
raise Exception("XBZRLE RAM compression is not supported yet")
elif flags & self.RAM_SAVE_FLAG_HOOK:
raise Exception("RAM hooks don't make sense with files")
# End of RAM section
if flags & self.RAM_SAVE_FLAG_EOS:
break
if flags != 0:
raise Exception("Unknown RAM flags: %x" % flags)
def __del__(self):
if self.write_memory:
for key in self.files:
self.files[key].close()
class HTABSection(object):
HASH_PTE_SIZE_64 = 16
def __init__(self, file, version_id, device, section_key):
if version_id != 1:
raise Exception("Unknown HTAB version %d" % version_id)
self.file = file
self.section_key = section_key
def read(self):
header = self.file.read32()
if (header == -1):
# "no HPT" encoding
return
if (header > 0):
# First section, just the hash shift
return
# Read until end marker
while True:
index = self.file.read32()
n_valid = self.file.read16()
n_invalid = self.file.read16()
if index == 0 and n_valid == 0 and n_invalid == 0:
break
self.file.readvar(n_valid * self.HASH_PTE_SIZE_64)
def getDict(self):
return ""
class ConfigurationSection(object):
def __init__(self, file):
self.file = file
def read(self):
name_len = self.file.read32()
name = self.file.readstr(len = name_len)
class VMSDFieldGeneric(object):
def __init__(self, desc, file):
self.file = file
self.desc = desc
self.data = ""
def __repr__(self):
return str(self.__str__())
def __str__(self):
return " ".join("{0:02x}".format(c) for c in self.data)
def getDict(self):
return self.__str__()
def read(self):
size = int(self.desc['size'])
self.data = self.file.readvar(size)
return self.data
class VMSDFieldInt(VMSDFieldGeneric):
def __init__(self, desc, file):
super(VMSDFieldInt, self).__init__(desc, file)
self.size = int(desc['size'])
self.format = '0x%%0%dx' % (self.size * 2)
self.sdtype = '>i%d' % self.size
self.udtype = '>u%d' % self.size
def __repr__(self):
if self.data < 0:
return ('%s (%d)' % ((self.format % self.udata), self.data))
else:
return self.format % self.data
def __str__(self):
return self.__repr__()
def getDict(self):
return self.__str__()
def read(self):
super(VMSDFieldInt, self).read()
self.sdata = int.from_bytes(self.data, byteorder='big', signed=True)
self.udata = int.from_bytes(self.data, byteorder='big', signed=False)
self.data = self.sdata
return self.data
class VMSDFieldUInt(VMSDFieldInt):
def __init__(self, desc, file):
super(VMSDFieldUInt, self).__init__(desc, file)
def read(self):
super(VMSDFieldUInt, self).read()
self.data = self.udata
return self.data
class VMSDFieldIntLE(VMSDFieldInt):
def __init__(self, desc, file):
super(VMSDFieldIntLE, self).__init__(desc, file)
self.dtype = '<i%d' % self.size
class VMSDFieldBool(VMSDFieldGeneric):
def __init__(self, desc, file):
super(VMSDFieldBool, self).__init__(desc, file)
def __repr__(self):
return self.data.__repr__()
def __str__(self):
return self.data.__str__()
def getDict(self):
return self.data
def read(self):
super(VMSDFieldBool, self).read()
if self.data[0] == 0:
self.data = False
else:
self.data = True
return self.data
class VMSDFieldStruct(VMSDFieldGeneric):
QEMU_VM_SUBSECTION = 0x05
def __init__(self, desc, file):
super(VMSDFieldStruct, self).__init__(desc, file)
self.data = collections.OrderedDict()
# When we see compressed array elements, unfold them here
new_fields = []
for field in self.desc['struct']['fields']:
if not 'array_len' in field:
new_fields.append(field)
continue
array_len = field.pop('array_len')
field['index'] = 0
new_fields.append(field)
for i in range(1, array_len):
c = field.copy()
c['index'] = i
new_fields.append(c)
self.desc['struct']['fields'] = new_fields
def __repr__(self):
return self.data.__repr__()
def __str__(self):
return self.data.__str__()
def read(self):
for field in self.desc['struct']['fields']:
try:
reader = vmsd_field_readers[field['type']]
except:
reader = 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'])
else:
self.data[field['name']] = field['data']
if 'subsections' in self.desc['struct']:
for subsection in self.desc['struct']['subsections']:
if self.file.read8() != self.QEMU_VM_SUBSECTION:
raise Exception("Subsection %s not found at offset %x" % ( subsection['vmsd_name'], self.file.tell()))
name = self.file.readstr()
version_id = self.file.read32()
self.data[name] = VMSDSection(self.file, version_id, subsection, (name, 0))
self.data[name].read()
def getDictItem(self, value):
# Strings would fall into the array category, treat
# them specially
if value.__class__ is ''.__class__:
return value
try:
return self.getDictOrderedDict(value)
except:
try:
return self.getDictArray(value)
except:
try:
return value.getDict()
except:
return value
def getDictArray(self, array):
r = []
for value in array:
r.append(self.getDictItem(value))
return r
def getDictOrderedDict(self, dict):
r = collections.OrderedDict()
for (key, value) in dict.items():
r[key] = self.getDictItem(value)
return r
def getDict(self):
return self.getDictOrderedDict(self.data)
vmsd_field_readers = {
"bool" : VMSDFieldBool,
"int8" : VMSDFieldInt,
"int16" : VMSDFieldInt,
"int32" : VMSDFieldInt,
"int32 equal" : VMSDFieldInt,
"int32 le" : VMSDFieldIntLE,
"int64" : VMSDFieldInt,
"uint8" : VMSDFieldUInt,
"uint16" : VMSDFieldUInt,
"uint32" : VMSDFieldUInt,
"uint32 equal" : VMSDFieldUInt,
"uint64" : VMSDFieldUInt,
"int64 equal" : VMSDFieldInt,
"uint8 equal" : VMSDFieldInt,
"uint16 equal" : VMSDFieldInt,
"float64" : VMSDFieldGeneric,
"timer" : VMSDFieldGeneric,
"buffer" : VMSDFieldGeneric,
"unused_buffer" : VMSDFieldGeneric,
"bitmap" : VMSDFieldGeneric,
"struct" : VMSDFieldStruct,
"unknown" : VMSDFieldGeneric,
}
class VMSDSection(VMSDFieldStruct):
def __init__(self, file, version_id, device, section_key):
self.file = file
self.data = ""
self.vmsd_name = ""
self.section_key = section_key
desc = device
if 'vmsd_name' in device:
self.vmsd_name = device['vmsd_name']
# A section really is nothing but a FieldStruct :)
super(VMSDSection, self).__init__({ 'struct' : desc }, file)
###############################################################################
class MigrationDump(object):
QEMU_VM_FILE_MAGIC = 0x5145564d
QEMU_VM_FILE_VERSION = 0x00000003
QEMU_VM_EOF = 0x00
QEMU_VM_SECTION_START = 0x01
QEMU_VM_SECTION_PART = 0x02
QEMU_VM_SECTION_END = 0x03
QEMU_VM_SECTION_FULL = 0x04
QEMU_VM_SUBSECTION = 0x05
QEMU_VM_VMDESCRIPTION = 0x06
QEMU_VM_CONFIGURATION = 0x07
QEMU_VM_SECTION_FOOTER= 0x7e
def __init__(self, filename):
self.section_classes = { ( 'ram', 0 ) : [ RamSection, None ],
( 'spapr/htab', 0) : ( HTABSection, None ) }
self.filename = filename
self.vmsd_desc = None
def read(self, desc_only = False, dump_memory = False, write_memory = False):
# Read in the whole file
file = MigrationFile(self.filename)
# File magic
data = file.read32()
if data != self.QEMU_VM_FILE_MAGIC:
raise Exception("Invalid file magic %x" % data)
# Version (has to be v3)
data = file.read32()
if data != self.QEMU_VM_FILE_VERSION:
raise Exception("Invalid version number %d" % data)
self.load_vmsd_json(file)
# Read sections
self.sections = collections.OrderedDict()
if desc_only:
return
ramargs = {}
ramargs['page_size'] = self.vmsd_desc['page_size']
ramargs['dump_memory'] = dump_memory
ramargs['write_memory'] = write_memory
self.section_classes[('ram',0)][1] = ramargs
while True:
section_type = file.read8()
if section_type == self.QEMU_VM_EOF:
break
elif section_type == self.QEMU_VM_CONFIGURATION:
section = ConfigurationSection(file)
section.read()
elif section_type == self.QEMU_VM_SECTION_START or section_type == self.QEMU_VM_SECTION_FULL:
section_id = file.read32()
name = file.readstr()
instance_id = file.read32()
version_id = file.read32()
section_key = (name, instance_id)
classdesc = self.section_classes[section_key]
section = classdesc[0](file, version_id, classdesc[1], section_key)
self.sections[section_id] = section
section.read()
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_SECTION_FOOTER:
read_section_id = file.read32()
if read_section_id != section_id:
raise Exception("Mismatched section footer: %x vs %x" % (read_section_id, section_id))
else:
raise Exception("Unknown section type: %d" % section_type)
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)
for device in self.vmsd_desc['devices']:
key = (device['name'], device['instance_id'])
value = ( VMSDSection, device )
self.section_classes[key] = value
def getDict(self):
r = collections.OrderedDict()
for (key, value) in self.sections.items():
key = "%s (%d)" % ( value.section_key[0], key )
r[key] = value.getDict()
return r
###############################################################################
class JSONEncoder(json.JSONEncoder):
def default(self, o):
if isinstance(o, VMSDFieldGeneric):
return str(o)
return json.JSONEncoder.default(self, o)
parser = argparse.ArgumentParser()
parser.add_argument("-f", "--file", help='migration dump to read from', required=True)
parser.add_argument("-m", "--memory", help='dump RAM contents as well', action='store_true')
parser.add_argument("-d", "--dump", help='what to dump ("state" or "desc")', default='state')
parser.add_argument("-x", "--extract", help='extract contents into individual files', action='store_true')
args = parser.parse_args()
jsonenc = JSONEncoder(indent=4, separators=(',', ': '))
if args.extract:
dump = MigrationDump(args.file)
dump.read(desc_only = True)
print("desc.json")
f = open("desc.json", "wb")
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", "wb")
f.truncate()
f.write(jsonenc.encode(dict))
f.close()
elif args.dump == "state":
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 dump")
