scripts/qemugdb/mtree.py

   1 #
   2 # GDB debugging support
   3 #
   4 # Copyright 2012 Red Hat, Inc. and/or its affiliates
   5 #
   6 # Authors:
   7 #  Avi Kivity <avi@redhat.com>
   8 #
   9 # This work is licensed under the terms of the GNU GPL, version 2 or
  10 # later.  See the COPYING file in the top-level directory.
  11
  12 # 'qemu mtree' -- display the memory hierarchy
  13
  14 import gdb
  15
  16 def isnull(ptr):
  17     return ptr == gdb.Value(0).cast(ptr.type)
  18
  19 def int128(p):
  20     '''Read an Int128 type to a python integer.
  21
  22     QEMU can be built with native Int128 support so we need to detect
  23     if the value is a structure or the native type.
  24     '''
  25     if p.type.code == gdb.TYPE_CODE_STRUCT:
  26         return int(p['lo']) + (int(p['hi']) << 64)
  27     else:
  28         return int(("%s" % p), 16)
  29
  30 class MtreeCommand(gdb.Command):
  31     '''Display the memory tree hierarchy'''
  32     def __init__(self):
  33         gdb.Command.__init__(self, 'qemu mtree', gdb.COMMAND_DATA,
  34                              gdb.COMPLETE_NONE)
  35         self.queue = []
  36     def invoke(self, arg, from_tty):
  37         self.seen = set()
  38         self.queue_root('address_space_memory')
  39         self.queue_root('address_space_io')
  40         self.process_queue()
  41     def queue_root(self, varname):
  42         ptr = gdb.parse_and_eval(varname)['root']
  43         self.queue.append(ptr)
  44     def process_queue(self):
  45         while self.queue:
  46             ptr = self.queue.pop(0)
  47             if int(ptr) in self.seen:
  48                 continue
  49             self.print_item(ptr)
  50     def print_item(self, ptr, offset = gdb.Value(0), level = 0):
  51         self.seen.add(int(ptr))
  52         addr = ptr['addr']
  53         addr += offset
  54         size = int128(ptr['size'])
  55         alias = ptr['alias']
  56         klass = ''
  57         if not isnull(alias):
  58             klass = ' (alias)'
  59         elif not isnull(ptr['ops']):
  60             klass = ' (I/O)'
  61         elif bool(ptr['ram']):
  62             klass = ' (RAM)'
  63         gdb.write('%s%016x-%016x %s%s (@ %s)\n'
  64                   % ('  ' * level,
  65                      int(addr),
  66                      int(addr + (size - 1)),
  67                      ptr['name'].string(),
  68                      klass,
  69                      ptr,
  70                      ),
  71                   gdb.STDOUT)
  72         if not isnull(alias):
  73             gdb.write('%s    alias: %s@%016x (@ %s)\n' %
  74                       ('  ' * level,
  75                        alias['name'].string(),
  76                        int(ptr['alias_offset']),
  77                        alias,
  78                        ),
  79                       gdb.STDOUT)
  80             self.queue.append(alias)
  81         subregion = ptr['subregions']['tqh_first']
  82         level += 1
  83         while not isnull(subregion):
  84             self.print_item(subregion, addr, level)
  85             subregion = subregion['subregions_link']['tqe_next']