xref: /openbmc/qemu/scripts/qemugdb/mtree.py (revision dc5bd18f) 
1#!/usr/bin/python
2
3# GDB debugging support
4#
5# Copyright 2012 Red Hat, Inc. and/or its affiliates
6#
7# Authors:
8#  Avi Kivity <avi@redhat.com>
9#
10# This work is licensed under the terms of the GNU GPL, version 2.  See
11# the COPYING file in the top-level directory.
12#
13# Contributions after 2012-01-13 are licensed under the terms of the
14# GNU GPL, version 2 or (at your option) any later version.
15
16# 'qemu mtree' -- display the memory hierarchy
17
18import gdb
19
20def isnull(ptr):
21    return ptr == gdb.Value(0).cast(ptr.type)
22
23def int128(p):
24    '''Read an Int128 type to a python integer.
25
26    QEMU can be built with native Int128 support so we need to detect
27    if the value is a structure or the native type.
28    '''
29    if p.type.code == gdb.TYPE_CODE_STRUCT:
30        return int(p['lo']) + (int(p['hi']) << 64)
31    else:
32        return int(("%s" % p), 16)
33
34class MtreeCommand(gdb.Command):
35    '''Display the memory tree hierarchy'''
36    def __init__(self):
37        gdb.Command.__init__(self, 'qemu mtree', gdb.COMMAND_DATA,
38                             gdb.COMPLETE_NONE)
39        self.queue = []
40    def invoke(self, arg, from_tty):
41        self.seen = set()
42        self.queue_root('address_space_memory')
43        self.queue_root('address_space_io')
44        self.process_queue()
45    def queue_root(self, varname):
46        ptr = gdb.parse_and_eval(varname)['root']
47        self.queue.append(ptr)
48    def process_queue(self):
49        while self.queue:
50            ptr = self.queue.pop(0)
51            if int(ptr) in self.seen:
52                continue
53            self.print_item(ptr)
54    def print_item(self, ptr, offset = gdb.Value(0), level = 0):
55        self.seen.add(int(ptr))
56        addr = ptr['addr']
57        addr += offset
58        size = int128(ptr['size'])
59        alias = ptr['alias']
60        klass = ''
61        if not isnull(alias):
62            klass = ' (alias)'
63        elif not isnull(ptr['ops']):
64            klass = ' (I/O)'
65        elif bool(ptr['ram']):
66            klass = ' (RAM)'
67        gdb.write('%s%016x-%016x %s%s (@ %s)\n'
68                  % ('  ' * level,
69                     int(addr),
70                     int(addr + (size - 1)),
71                     ptr['name'].string(),
72                     klass,
73                     ptr,
74                     ),
75                  gdb.STDOUT)
76        if not isnull(alias):
77            gdb.write('%s    alias: %s@%016x (@ %s)\n' %
78                      ('  ' * level,
79                       alias['name'].string(),
80                       int(ptr['alias_offset']),
81                       alias,
82                       ),
83                      gdb.STDOUT)
84            self.queue.append(alias)
85        subregion = ptr['subregions']['tqh_first']
86        level += 1
87        while not isnull(subregion):
88            self.print_item(subregion, addr, level)
89            subregion = subregion['subregions_link']['tqe_next']
90
91