[PATCH v13 00/11] iotests: Dump QCOW2 dirty bitmaps metadata

[PATCH v13 00/11] iotests: Dump QCOW2 dirty bitmaps metadata

[Andrey Shinkevich]

Add dirty bitmap information to QCOW2 metadata dump in the qcow2_format.py.

v13:
  01: Bitmaps are added without launching VM (suggested by Eric).
      The code amendments suggested by Vladimir.
  07: Bitmap table entry size zeroed up for all types but serialized.
  09: The extra dict variables removed. to_dict() renamed to to_json().
      The to_json() added to the class Qcow2BitmapTable. (By Vladimir).


Andrey Shinkevich (11):
  iotests: add test for QCOW2 header dump
  qcow2_format.py: make printable data an extension class member
  qcow2_format.py: change Qcow2BitmapExt initialization method
  qcow2_format.py: dump bitmap flags in human readable way.
  qcow2_format.py: Dump bitmap directory information
  qcow2_format.py: pass cluster size to substructures
  qcow2_format.py: Dump bitmap table serialized entries
  qcow2.py: Introduce '-j' key to dump in JSON format
  qcow2_format.py: collect fields to dump in JSON format
  qcow2_format.py: support dumping metadata in JSON format
  iotests: dump QCOW2 header in JSON in #303

 tests/qemu-iotests/303             |  63 +++++++++++
 tests/qemu-iotests/303.out         | 158 +++++++++++++++++++++++++++
 tests/qemu-iotests/group           |   1 +
 tests/qemu-iotests/qcow2.py        |  18 +++-
 tests/qemu-iotests/qcow2_format.py | 215 ++++++++++++++++++++++++++++++++++---
 5 files changed, 434 insertions(+), 21 deletions(-)
 create mode 100755 tests/qemu-iotests/303
 create mode 100644 tests/qemu-iotests/303.out

-- 
1.8.3.1

[PATCH v13 01/11] iotests: add test for QCOW2 header dump

[Andrey Shinkevich]

The simple script creates a QCOW2 image and fills it with some data.
Two bitmaps are created as well. Then the script reads the image header
with extensions from the disk by running the script qcow2.py and dumps
the information to the output. Other entities, such as snapshots, may
be added to the test later.

Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/303     | 60 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/303.out | 60 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/group   |  1 +
 3 files changed, 121 insertions(+)
 create mode 100755 tests/qemu-iotests/303
 create mode 100644 tests/qemu-iotests/303.out

diff --git a/tests/qemu-iotests/303 b/tests/qemu-iotests/303
new file mode 100755
index 0000000..e9accdc
--- /dev/null
+++ b/tests/qemu-iotests/303
@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+#
+# Test for dumping of qcow2 image metadata
+#
+# Copyright (c) 2020 Virtuozzo International GmbH
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import iotests
+import subprocess
+from iotests import qemu_img_create, qemu_io, file_path, log, filter_qemu_io
+
+iotests.script_initialize(supported_fmts=['qcow2'])
+
+disk = file_path('disk')
+chunk = 1024 * 1024
+
+
+def create_bitmap(bitmap_number, disabled):
+    granularity = 1 << (14 + bitmap_number)
+    bitmap_name = 'bitmap-' + str(bitmap_number)
+    args = ['bitmap', '--add', '-g', f'{granularity}', '-f', iotests.imgfmt,
+            disk, bitmap_name]
+    if disabled:
+        args.append('--disable')
+
+    iotests.qemu_img_pipe(*args)
+
+
+def write_to_disk(offset, size):
+    write = f'write {offset} {size}'
+    log(qemu_io('-c', write, disk), filters=[filter_qemu_io])
+
+
+def add_bitmap(num, begin, end, disabled):
+    log(f'Add bitmap {num}')
+    create_bitmap(num, disabled)
+    for i in range(begin, end):
+        write_to_disk((i) * chunk, chunk)
+    log('')
+
+
+qemu_img_create('-f', iotests.imgfmt, disk, '10M')
+
+add_bitmap(1, 0, 6, False)
+add_bitmap(2, 6, 8, True)
+dump = ['qcow2.py', disk, 'dump-header']
+subprocess.run(dump)
diff --git a/tests/qemu-iotests/303.out b/tests/qemu-iotests/303.out
new file mode 100644
index 0000000..8d7973c
--- /dev/null
+++ b/tests/qemu-iotests/303.out
@@ -0,0 +1,60 @@
+Add bitmap 1
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 1048576
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 2097152
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 3145728
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 4194304
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 5242880
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+
+Add bitmap 2
+wrote 1048576/1048576 bytes at offset 6291456
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+wrote 1048576/1048576 bytes at offset 7340032
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+
+magic                     0x514649fb
+version                   3
+backing_file_offset       0x0
+backing_file_size         0x0
+cluster_bits              16
+size                      10485760
+crypt_method              0
+l1_size                   1
+l1_table_offset           0x30000
+refcount_table_offset     0x10000
+refcount_table_clusters   1
+nb_snapshots              0
+snapshot_offset           0x0
+incompatible_features     []
+compatible_features       []
+autoclear_features        [0]
+refcount_order            4
+header_length             112
+
+Header extension:
+magic                     0x6803f857 (Feature table)
+length                    336
+data                      <binary>
+
+Header extension:
+magic                     0x23852875 (Bitmaps)
+length                    24
+nb_bitmaps                2
+reserved32                0
+bitmap_directory_size     0x40
+bitmap_directory_offset   0x9d0000
+
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 025ed52..7e12e1f 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -309,3 +309,4 @@
 299 auto quick
 301 backing quick
 302 quick
+303 rw quick
-- 
1.8.3.1

[PATCH v13 02/11] qcow2_format.py: make printable data an extension class member

[Andrey Shinkevich]

Let us differ binary data type from string one for the extension data
variable and keep the string as the QcowHeaderExtension class member.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index cc432e7..2f3681b 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -165,6 +165,13 @@ class QcowHeaderExtension(Qcow2Struct):
             self.data = fd.read(padded)
             assert self.data is not None
 
+        data_str = self.data[:self.length]
+        if all(c in string.printable.encode('ascii') for c in data_str):
+            data_str = f"'{ data_str.decode('ascii') }'"
+        else:
+            data_str = '<binary>'
+        self.data_str = data_str
+
         if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
             self.obj = Qcow2BitmapExt(data=self.data)
         else:
@@ -174,12 +181,7 @@ class QcowHeaderExtension(Qcow2Struct):
         super().dump()
 
         if self.obj is None:
-            data = self.data[:self.length]
-            if all(c in string.printable.encode('ascii') for c in data):
-                data = f"'{ data.decode('ascii') }'"
-            else:
-                data = '<binary>'
-            print(f'{"data":<25} {data}')
+            print(f'{"data":<25} {self.data_str}')
         else:
             self.obj.dump()
 
-- 
1.8.3.1

[PATCH v13 03/11] qcow2_format.py: change Qcow2BitmapExt initialization method

[Andrey Shinkevich]

There are two ways to initialize a class derived from Qcow2Struct:
1. Pass a block of binary data to the constructor.
2. Pass the file descriptor to allow reading the file from constructor.
Let's change the Qcow2BitmapExt initialization method from 1 to 2 to
support a scattered reading in the initialization chain.
The implementation comes with the patch that follows.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 2f3681b..d4a9974 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -113,6 +113,11 @@ class Qcow2BitmapExt(Qcow2Struct):
         ('u64', '{:#x}', 'bitmap_directory_offset')
     )
 
+    def __init__(self, fd):
+        super().__init__(fd=fd)
+        tail = struct.calcsize(self.fmt) % 8
+        if tail:
+            fd.seek(8 - tail, 1)
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
 
@@ -161,21 +166,24 @@ class QcowHeaderExtension(Qcow2Struct):
         else:
             assert all(v is None for v in (magic, length, data))
             super().__init__(fd=fd)
-            padded = (self.length + 7) & ~7
-            self.data = fd.read(padded)
-            assert self.data is not None
-
-        data_str = self.data[:self.length]
-        if all(c in string.printable.encode('ascii') for c in data_str):
-            data_str = f"'{ data_str.decode('ascii') }'"
-        else:
-            data_str = '<binary>'
-        self.data_str = data_str
+            if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
+                self.obj = Qcow2BitmapExt(fd=fd)
+                self.data = None
+            else:
+                padded = (self.length + 7) & ~7
+                self.data = fd.read(padded)
+                assert self.data is not None
+                self.obj = None
+
+        if self.data is not None:
+            data_str = self.data[:self.length]
+            if all(c in string.printable.encode(
+                'ascii') for c in data_str):
+                data_str = f"'{ data_str.decode('ascii') }'"
+            else:
+                data_str = '<binary>'
+            self.data_str = data_str
 
-        if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
-            self.obj = Qcow2BitmapExt(data=self.data)
-        else:
-            self.obj = None
 
     def dump(self):
         super().dump()
-- 
1.8.3.1

[PATCH v13 04/11] qcow2_format.py: dump bitmap flags in human readable way.

[Andrey Shinkevich]

Introduce the class BitmapFlags that parses a bitmap flags mask.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index d4a9974..b447344 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -40,6 +40,22 @@ class Flags64(Qcow2Field):
         return str(bits)
 
 
+class BitmapFlags(Qcow2Field):
+
+    flags = {
+        0x1: 'in-use',
+        0x2: 'auto'
+    }
+
+    def __str__(self):
+        bits = []
+        for bit in range(64):
+            flag = self.value & (1 << bit)
+            if flag:
+                bits.append(self.flags.get(flag, f'bit-{bit}'))
+        return f'{self.value:#x} ({bits})'
+
+
 class Enum(Qcow2Field):
 
     def __str__(self):
-- 
1.8.3.1

[PATCH v13 05/11] qcow2_format.py: Dump bitmap directory information

[Andrey Shinkevich]

Read and dump entries from the bitmap directory of QCOW2 image.

Header extension:
magic                     0x23852875 (Bitmaps)
...
Bitmap name               bitmap-1
bitmap_table_offset       0xf0000
bitmap_table_size         1
flags                     0x2 (['auto'])
type                      1
granularity_bits          16
name_size                 8
extra_data_size           0

Suggested-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/303.out         | 18 +++++++++++++++
 tests/qemu-iotests/qcow2_format.py | 47 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/tests/qemu-iotests/303.out b/tests/qemu-iotests/303.out
index 8d7973c..038ba93 100644
--- a/tests/qemu-iotests/303.out
+++ b/tests/qemu-iotests/303.out
@@ -58,3 +58,21 @@ reserved32                0
 bitmap_directory_size     0x40
 bitmap_directory_offset   0x9d0000
 
+Bitmap name               bitmap-1
+bitmap_table_offset       0x9b0000
+bitmap_table_size         1
+flags                     0x2 (['auto'])
+type                      1
+granularity_bits          15
+name_size                 8
+extra_data_size           0
+
+Bitmap name               bitmap-2
+bitmap_table_offset       0x9c0000
+bitmap_table_size         1
+flags                     0x0 ([])
+type                      1
+granularity_bits          16
+name_size                 8
+extra_data_size           0
+
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index b447344..05a8aa9 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -134,6 +134,53 @@ class Qcow2BitmapExt(Qcow2Struct):
         tail = struct.calcsize(self.fmt) % 8
         if tail:
             fd.seek(8 - tail, 1)
+        position = fd.tell()
+        self.read_bitmap_directory(fd)
+        fd.seek(position)
+
+    def read_bitmap_directory(self, fd):
+        fd.seek(self.bitmap_directory_offset)
+        self.bitmap_directory = \
+            [Qcow2BitmapDirEntry(fd) for _ in range(self.nb_bitmaps)]
+
+    def dump(self):
+        super().dump()
+        for entry in self.bitmap_directory:
+            print()
+            entry.dump()
+
+
+class Qcow2BitmapDirEntry(Qcow2Struct):
+
+    fields = (
+        ('u64', '{:#x}', 'bitmap_table_offset'),
+        ('u32', '{}', 'bitmap_table_size'),
+        ('u32', BitmapFlags, 'flags'),
+        ('u8',  '{}', 'type'),
+        ('u8',  '{}', 'granularity_bits'),
+        ('u16', '{}', 'name_size'),
+        ('u32', '{}', 'extra_data_size')
+    )
+
+    def __init__(self, fd):
+        super().__init__(fd=fd)
+        # Seek relative to the current position in the file
+        fd.seek(self.extra_data_size, 1)
+        bitmap_name = fd.read(self.name_size)
+        self.name = bitmap_name.decode('ascii')
+        # Move position to the end of the entry in the directory
+        entry_raw_size = self.bitmap_dir_entry_raw_size()
+        padding = ((entry_raw_size + 7) & ~7) - entry_raw_size
+        fd.seek(padding, 1)
+
+    def bitmap_dir_entry_raw_size(self):
+        return struct.calcsize(self.fmt) + self.name_size + \
+            self.extra_data_size
+
+    def dump(self):
+        print(f'{"Bitmap name":<25} {self.name}')
+        super(Qcow2BitmapDirEntry, self).dump()
+
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
 
-- 
1.8.3.1

[PATCH v13 06/11] qcow2_format.py: pass cluster size to substructures

[Andrey Shinkevich]

The cluster size of an image is the QcowHeader class member and may be
obtained by dependent extension structures such as Qcow2BitmapExt for
further bitmap table details print.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 05a8aa9..ca0d350 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -129,19 +129,21 @@ class Qcow2BitmapExt(Qcow2Struct):
         ('u64', '{:#x}', 'bitmap_directory_offset')
     )
 
-    def __init__(self, fd):
+    def __init__(self, fd, cluster_size):
         super().__init__(fd=fd)
         tail = struct.calcsize(self.fmt) % 8
         if tail:
             fd.seek(8 - tail, 1)
         position = fd.tell()
+        self.cluster_size = cluster_size
         self.read_bitmap_directory(fd)
         fd.seek(position)
 
     def read_bitmap_directory(self, fd):
         fd.seek(self.bitmap_directory_offset)
         self.bitmap_directory = \
-            [Qcow2BitmapDirEntry(fd) for _ in range(self.nb_bitmaps)]
+            [Qcow2BitmapDirEntry(fd, cluster_size=self.cluster_size)
+             for _ in range(self.nb_bitmaps)]
 
     def dump(self):
         super().dump()
@@ -162,8 +164,9 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         ('u32', '{}', 'extra_data_size')
     )
 
-    def __init__(self, fd):
+    def __init__(self, fd, cluster_size):
         super().__init__(fd=fd)
+        self.cluster_size = cluster_size
         # Seek relative to the current position in the file
         fd.seek(self.extra_data_size, 1)
         bitmap_name = fd.read(self.name_size)
@@ -203,11 +206,13 @@ class QcowHeaderExtension(Qcow2Struct):
         # then padding to next multiply of 8
     )
 
-    def __init__(self, magic=None, length=None, data=None, fd=None):
+    def __init__(self, magic=None, length=None, data=None, fd=None,
+                 cluster_size=None):
         """
         Support both loading from fd and creation from user data.
         For fd-based creation current position in a file will be used to read
         the data.
+        The cluster_size value may be obtained by dependent structures.
 
         This should be somehow refactored and functionality should be moved to
         superclass (to allow creation of any qcow2 struct), but then, fields
@@ -230,7 +235,7 @@ class QcowHeaderExtension(Qcow2Struct):
             assert all(v is None for v in (magic, length, data))
             super().__init__(fd=fd)
             if self.magic == QCOW2_EXT_MAGIC_BITMAPS:
-                self.obj = Qcow2BitmapExt(fd=fd)
+                self.obj = Qcow2BitmapExt(fd=fd, cluster_size=cluster_size)
                 self.data = None
             else:
                 padded = (self.length + 7) & ~7
@@ -319,7 +324,7 @@ class QcowHeader(Qcow2Struct):
             end = self.cluster_size
 
         while fd.tell() < end:
-            ext = QcowHeaderExtension(fd=fd)
+            ext = QcowHeaderExtension(fd=fd, cluster_size=self.cluster_size)
             if ext.magic == 0:
                 break
             else:
-- 
1.8.3.1

[PATCH v13 07/11] qcow2_format.py: Dump bitmap table serialized entries

[Andrey Shinkevich]

Add bitmap table information to the QCOW2 metadata dump.

Bitmap name               bitmap-1
...
Bitmap table   type            size         offset
0              serialized      65536        10092544
1              all-zeroes      0            0
2              all-zeroes      0            0

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/303.out         |  4 +++
 tests/qemu-iotests/qcow2_format.py | 50 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/tests/qemu-iotests/303.out b/tests/qemu-iotests/303.out
index 038ba93..70828e0 100644
--- a/tests/qemu-iotests/303.out
+++ b/tests/qemu-iotests/303.out
@@ -66,6 +66,8 @@ type                      1
 granularity_bits          15
 name_size                 8
 extra_data_size           0
+Bitmap table   type            size         offset
+0              serialized      65536        10092544
 
 Bitmap name               bitmap-2
 bitmap_table_offset       0x9c0000
@@ -75,4 +77,6 @@ type                      1
 granularity_bits          16
 name_size                 8
 extra_data_size           0
+Bitmap table   type            size         offset
+0              all-zeroes      0            0
 
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index ca0d350..574249b 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -175,6 +175,10 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         entry_raw_size = self.bitmap_dir_entry_raw_size()
         padding = ((entry_raw_size + 7) & ~7) - entry_raw_size
         fd.seek(padding, 1)
+        self.bitmap_table = Qcow2BitmapTable(fd=fd,
+                                             offset=self.bitmap_table_offset,
+                                             nb_entries=self.bitmap_table_size,
+                                             cluster_size=self.cluster_size)
 
     def bitmap_dir_entry_raw_size(self):
         return struct.calcsize(self.fmt) + self.name_size + \
@@ -183,6 +187,52 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
     def dump(self):
         print(f'{"Bitmap name":<25} {self.name}')
         super(Qcow2BitmapDirEntry, self).dump()
+        self.bitmap_table.dump()
+
+
+class Qcow2BitmapTableEntry(Qcow2Struct):
+
+    fields = (
+        ('u64',  '{}', 'entry'),
+    )
+
+    BME_TABLE_ENTRY_RESERVED_MASK = 0xff000000000001fe
+    BME_TABLE_ENTRY_OFFSET_MASK = 0x00fffffffffffe00
+    BME_TABLE_ENTRY_FLAG_ALL_ONES = 1
+
+    def __init__(self, fd):
+        super().__init__(fd=fd)
+        self.reserved = self.entry & self.BME_TABLE_ENTRY_RESERVED_MASK
+        self.offset = self.entry & self.BME_TABLE_ENTRY_OFFSET_MASK
+        if self.offset:
+            if self.entry & self.BME_TABLE_ENTRY_FLAG_ALL_ONES:
+                self.type = 'invalid'
+            else:
+                self.type = 'serialized'
+        elif self.entry & self.BME_TABLE_ENTRY_FLAG_ALL_ONES:
+            self.type = 'all-ones'
+        else:
+            self.type = 'all-zeroes'
+
+
+class Qcow2BitmapTable:
+
+    def __init__(self, fd, offset, nb_entries, cluster_size):
+        self.cluster_size = cluster_size
+        position = fd.tell()
+        fd.seek(offset)
+        self.entries = [Qcow2BitmapTableEntry(fd) for _ in range(nb_entries)]
+        fd.seek(position)
+
+    def dump(self):
+        bitmap_table = enumerate(self.entries)
+        print(f'{"Bitmap table":<14} {"type":<15} {"size":<12} {"offset"}')
+        for i, entry in bitmap_table:
+            if entry.type == 'serialized':
+                size = self.cluster_size
+            else:
+                size = 0
+            print(f'{i:<14} {entry.type:<15} {size:<12} {entry.offset}')
 
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
-- 
1.8.3.1

[PATCH v13 08/11] qcow2.py: Introduce '-j' key to dump in JSON format

[Andrey Shinkevich]

Add the command key to the qcow2.py arguments list to dump QCOW2
metadata in JSON format. Here is the suggested way to do that. The
implementation of the dump in JSON format is in the patch that follows.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2.py        | 18 ++++++++++++++----
 tests/qemu-iotests/qcow2_format.py |  4 ++--
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/tests/qemu-iotests/qcow2.py b/tests/qemu-iotests/qcow2.py
index 0910e6a..77ca59c 100755
--- a/tests/qemu-iotests/qcow2.py
+++ b/tests/qemu-iotests/qcow2.py
@@ -26,16 +26,19 @@ from qcow2_format import (
 )
 
 
+is_json = False
+
+
 def cmd_dump_header(fd):
     h = QcowHeader(fd)
-    h.dump()
+    h.dump(is_json)
     print()
-    h.dump_extensions()
+    h.dump_extensions(is_json)
 
 
 def cmd_dump_header_exts(fd):
     h = QcowHeader(fd)
-    h.dump_extensions()
+    h.dump_extensions(is_json)
 
 
 def cmd_set_header(fd, name, value):
@@ -151,11 +154,14 @@ def main(filename, cmd, args):
 
 
 def usage():
-    print("Usage: %s <file> <cmd> [<arg>, ...]" % sys.argv[0])
+    print("Usage: %s <file> <cmd> [<arg>, ...] [<key>, ...]" % sys.argv[0])
     print("")
     print("Supported commands:")
     for name, handler, num_args, desc in cmds:
         print("    %-20s - %s" % (name, desc))
+    print("")
+    print("Supported keys:")
+    print("    %-20s - %s" % ('-j', 'Dump in JSON format'))
 
 
 if __name__ == '__main__':
@@ -163,4 +169,8 @@ if __name__ == '__main__':
         usage()
         sys.exit(1)
 
+    is_json = '-j' in sys.argv
+    if is_json:
+        sys.argv.remove('-j')
+
     main(sys.argv[1], sys.argv[2], sys.argv[3:])
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 574249b..de0adcb 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -109,7 +109,7 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
         self.__dict__ = dict((field[2], values[i])
                              for i, field in enumerate(self.fields))
 
-    def dump(self):
+    def dump(self, is_json=False):
         for f in self.fields:
             value = self.__dict__[f[2]]
             if isinstance(f[1], str):
@@ -408,7 +408,7 @@ class QcowHeader(Qcow2Struct):
         buf = buf[0:header_bytes-1]
         fd.write(buf)
 
-    def dump_extensions(self):
+    def dump_extensions(self, is_json=False):
         for ex in self.extensions:
             print('Header extension:')
             ex.dump()
-- 
1.8.3.1

[PATCH v13 09/11] qcow2_format.py: collect fields to dump in JSON format

[Andrey Shinkevich]

As __dict__ is being extended with class members we do not want to
print, add the to_dict() method to classes that returns a dictionary
with desired fields and their values. Extend it in subclass when
necessary to print the final dictionary in the JSON output which
follows.

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index de0adcb..5a298b2 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -119,6 +119,9 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
 
             print('{:<25} {}'.format(f[2], value_str))
 
+    def to_json(self):
+        return dict((f[2], self.__dict__[f[2]]) for f in self.fields)
+
 
 class Qcow2BitmapExt(Qcow2Struct):
 
@@ -151,6 +154,11 @@ class Qcow2BitmapExt(Qcow2Struct):
             print()
             entry.dump()
 
+    def to_json(self):
+        fields_dict = super().to_json()
+        fields_dict['bitmap_directory'] = self.bitmap_directory
+        return fields_dict
+
 
 class Qcow2BitmapDirEntry(Qcow2Struct):
 
@@ -189,6 +197,14 @@ class Qcow2BitmapDirEntry(Qcow2Struct):
         super(Qcow2BitmapDirEntry, self).dump()
         self.bitmap_table.dump()
 
+    def to_json(self):
+        # Put the name ahead of the dict
+        return {
+            'name': self.name,
+            **super().to_json(),
+            'bitmap_table': self.bitmap_table
+        }
+
 
 class Qcow2BitmapTableEntry(Qcow2Struct):
 
@@ -214,6 +230,10 @@ class Qcow2BitmapTableEntry(Qcow2Struct):
         else:
             self.type = 'all-zeroes'
 
+    def to_json(self):
+        return {'type': self.type, 'offset': self.offset,
+                'reserved': self.reserved}
+
 
 class Qcow2BitmapTable:
 
@@ -234,6 +254,9 @@ class Qcow2BitmapTable:
                 size = 0
             print(f'{i:<14} {entry.type:<15} {size:<12} {entry.offset}')
 
+    def to_json(self):
+        return self.entries
+
 
 QCOW2_EXT_MAGIC_BITMAPS = 0x23852875
 
@@ -249,6 +272,9 @@ class QcowHeaderExtension(Qcow2Struct):
             0x44415441: 'Data file'
         }
 
+        def to_json(self):
+            return self.mapping.get(self.value, "<unknown>")
+
     fields = (
         ('u32', Magic, 'magic'),
         ('u32', '{}', 'length')
@@ -311,6 +337,16 @@ class QcowHeaderExtension(Qcow2Struct):
         else:
             self.obj.dump()
 
+    def to_json(self):
+        # Put the name ahead of the dict
+        res = {'name': self.Magic(self.magic), **super().to_json()}
+        if self.obj is not None:
+            res['data'] = self.obj
+        else:
+            res['data_str'] = self.data_str
+
+        return res
+
     @classmethod
     def create(cls, magic, data):
         return QcowHeaderExtension(magic, len(data), data)
-- 
1.8.3.1

[PATCH v13 10/11] qcow2_format.py: support dumping metadata in JSON format

[Andrey Shinkevich]

Implementation of dumping QCOW2 image metadata.
The sample output:
{
    "Header_extensions": [
        {
            "name": "Feature table",
            "magic": 1745090647,
            "length": 192,
            "data_str": "<binary>"
        },
        {
            "name": "Bitmaps",
            "magic": 595929205,
            "length": 24,
            "data": {
                "nb_bitmaps": 2,
                "reserved32": 0,
                "bitmap_directory_size": 64,
                "bitmap_directory_offset": 1048576,
                "bitmap_directory": [
                    {
                        "name": "bitmap-1",
                        "bitmap_table_offset": 589824,
                        "bitmap_table_size": 1,
                        "flags": 2,
                        "type": 1,
                        "granularity_bits": 15,
                        "name_size": 8,
                        "extra_data_size": 0,
                        "bitmap_table": [
                            {
                                "type": "serialized",
                                "offset": 655360
                            },
                            ...

Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/qcow2_format.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 5a298b2..8adc995 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -19,6 +19,15 @@
 
 import struct
 import string
+import json
+
+
+class ComplexEncoder(json.JSONEncoder):
+    def default(self, obj):
+        if hasattr(obj, 'to_json'):
+            return obj.to_json()
+        else:
+            return json.JSONEncoder.default(self, obj)
 
 
 class Qcow2Field:
@@ -110,6 +119,10 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
                              for i, field in enumerate(self.fields))
 
     def dump(self, is_json=False):
+        if is_json:
+            print(json.dumps(self.to_json(), indent=4, cls=ComplexEncoder))
+            return
+
         for f in self.fields:
             value = self.__dict__[f[2]]
             if isinstance(f[1], str):
@@ -445,6 +458,10 @@ class QcowHeader(Qcow2Struct):
         fd.write(buf)
 
     def dump_extensions(self, is_json=False):
+        if is_json:
+            print(json.dumps(self.extensions, indent=4, cls=ComplexEncoder))
+            return
+
         for ex in self.extensions:
             print('Header extension:')
             ex.dump()
-- 
1.8.3.1

[PATCH v13 11/11] iotests: dump QCOW2 header in JSON in #303

[Andrey Shinkevich]

Extend the test case #303 by dumping QCOW2 image metadata in JSON
format.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/303     |  3 ++
 tests/qemu-iotests/303.out | 76 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/tests/qemu-iotests/303 b/tests/qemu-iotests/303
index e9accdc..6c21774 100755
--- a/tests/qemu-iotests/303
+++ b/tests/qemu-iotests/303
@@ -58,3 +58,6 @@ add_bitmap(1, 0, 6, False)
 add_bitmap(2, 6, 8, True)
 dump = ['qcow2.py', disk, 'dump-header']
 subprocess.run(dump)
+# Dump the metadata in JSON format
+dump.append('-j')
+subprocess.run(dump)
diff --git a/tests/qemu-iotests/303.out b/tests/qemu-iotests/303.out
index 70828e0..7fa1ede 100644
--- a/tests/qemu-iotests/303.out
+++ b/tests/qemu-iotests/303.out
@@ -80,3 +80,79 @@ extra_data_size           0
 Bitmap table   type            size         offset
 0              all-zeroes      0            0
 
+{
+    "magic": 1363560955,
+    "version": 3,
+    "backing_file_offset": 0,
+    "backing_file_size": 0,
+    "cluster_bits": 16,
+    "size": 10485760,
+    "crypt_method": 0,
+    "l1_size": 1,
+    "l1_table_offset": 196608,
+    "refcount_table_offset": 65536,
+    "refcount_table_clusters": 1,
+    "nb_snapshots": 0,
+    "snapshot_offset": 0,
+    "incompatible_features": 0,
+    "compatible_features": 0,
+    "autoclear_features": 1,
+    "refcount_order": 4,
+    "header_length": 112
+}
+
+[
+    {
+        "name": "Feature table",
+        "magic": 1745090647,
+        "length": 336,
+        "data_str": "<binary>"
+    },
+    {
+        "name": "Bitmaps",
+        "magic": 595929205,
+        "length": 24,
+        "data": {
+            "nb_bitmaps": 2,
+            "reserved32": 0,
+            "bitmap_directory_size": 64,
+            "bitmap_directory_offset": 10289152,
+            "bitmap_directory": [
+                {
+                    "name": "bitmap-1",
+                    "bitmap_table_offset": 10158080,
+                    "bitmap_table_size": 1,
+                    "flags": 2,
+                    "type": 1,
+                    "granularity_bits": 15,
+                    "name_size": 8,
+                    "extra_data_size": 0,
+                    "bitmap_table": [
+                        {
+                            "type": "serialized",
+                            "offset": 10092544,
+                            "reserved": 0
+                        }
+                    ]
+                },
+                {
+                    "name": "bitmap-2",
+                    "bitmap_table_offset": 10223616,
+                    "bitmap_table_size": 1,
+                    "flags": 0,
+                    "type": 1,
+                    "granularity_bits": 16,
+                    "name_size": 8,
+                    "extra_data_size": 0,
+                    "bitmap_table": [
+                        {
+                            "type": "all-zeroes",
+                            "offset": 0,
+                            "reserved": 0
+                        }
+                    ]
+                }
+            ]
+        }
+    }
+]
-- 
1.8.3.1

Re: [PATCH v13 09/11] qcow2_format.py: collect fields to dump in JSON format

[Vladimir Sementsov-Ogievskiy]

06.08.2020 22:35, Andrey Shinkevich wrote:
> As __dict__ is being extended with class members we do not want to
> print, add the to_dict() method to classes that returns a dictionary

to_json() ... that returns a json-dumpable object

> with desired fields and their values. Extend it in subclass when
> necessary to print the final dictionary in the JSON output which
> follows.
> 
> Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>


-- 
Best regards,
Vladimir

Re: [PATCH v13 09/11] qcow2_format.py: collect fields to dump in JSON format

[Andrey Shinkevich]

On 07.08.2020 09:30, Vladimir Sementsov-Ogievskiy wrote:
> 06.08.2020 22:35, Andrey Shinkevich wrote:
>> As __dict__ is being extended with class members we do not want to
>> print, add the to_dict() method to classes that returns a dictionary
>
> to_json() ... that returns a json-dumpable object
>

New version to release with the commit message fix?

Andrey


>> with desired fields and their values. Extend it in subclass when
>> necessary to print the final dictionary in the JSON output which
>> follows.
>>
>> Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>
> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>
>

Re: [PATCH v13 09/11] qcow2_format.py: collect fields to dump in JSON format

[Vladimir Sementsov-Ogievskiy]

07.08.2020 11:03, Andrey Shinkevich wrote:
> On 07.08.2020 09:30, Vladimir Sementsov-Ogievskiy wrote:
>> 06.08.2020 22:35, Andrey Shinkevich wrote:
>>> As __dict__ is being extended with class members we do not want to
>>> print, add the to_dict() method to classes that returns a dictionary
>>
>> to_json() ... that returns a json-dumpable object
>>
> 
> New version to release with the commit message fix?
> 

Not worth resending, it can be touched when queuing.

> 
>>> with desired fields and their values. Extend it in subclass when
>>> necessary to print the final dictionary in the JSON output which
>>> follows.
>>>
>>> Suggested-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>> Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
>>
>> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>>
>>


-- 
Best regards,
Vladimir

Re: [PATCH v13 00/11] iotests: Dump QCOW2 dirty bitmaps metadata

[Andrey Shinkevich]

Dear Eric!

Vladimir has compeated reviewing this series. I have not received any 
other responses to it so far.

So, is it good for pull request now? Would you please consider taking 
this series as you did it with the Vladimir's related one?

Kindly,
Andrey


On 06.08.2020 22:35, Andrey Shinkevich wrote:
> Add dirty bitmap information to QCOW2 metadata dump in the qcow2_format.py.
>
> v13:
>    01: Bitmaps are added without launching VM (suggested by Eric).
>        The code amendments suggested by Vladimir.
>    07: Bitmap table entry size zeroed up for all types but serialized.
>    09: The extra dict variables removed. to_dict() renamed to to_json().
>        The to_json() added to the class Qcow2BitmapTable. (By Vladimir).
>
>
> Andrey Shinkevich (11):
>    iotests: add test for QCOW2 header dump
>    qcow2_format.py: make printable data an extension class member
>    qcow2_format.py: change Qcow2BitmapExt initialization method
>    qcow2_format.py: dump bitmap flags in human readable way.
>    qcow2_format.py: Dump bitmap directory information
>    qcow2_format.py: pass cluster size to substructures
>    qcow2_format.py: Dump bitmap table serialized entries
>    qcow2.py: Introduce '-j' key to dump in JSON format
>    qcow2_format.py: collect fields to dump in JSON format
>    qcow2_format.py: support dumping metadata in JSON format
>    iotests: dump QCOW2 header in JSON in #303
>
>   tests/qemu-iotests/303             |  63 +++++++++++
>   tests/qemu-iotests/303.out         | 158 +++++++++++++++++++++++++++
>   tests/qemu-iotests/group           |   1 +
>   tests/qemu-iotests/qcow2.py        |  18 +++-
>   tests/qemu-iotests/qcow2_format.py | 215 ++++++++++++++++++++++++++++++++++---
>   5 files changed, 434 insertions(+), 21 deletions(-)
>   create mode 100755 tests/qemu-iotests/303
>   create mode 100644 tests/qemu-iotests/303.out
>

Re: [PATCH v13 00/11] iotests: Dump QCOW2 dirty bitmaps metadata

[Eric Blake]

On 8/14/20 6:56 AM, Andrey Shinkevich wrote:
> Dear Eric!
> 
> Vladimir has compeated reviewing this series. I have not received any 
> other responses to it so far.
> 
> So, is it good for pull request now? Would you please consider taking 
> this series as you did it with the Vladimir's related one?

I've spent some time playing with this; I have now queued it on my 
bitmaps tree, and will be posting a pull request as soon as Paolo's 
meson changes settle.  I also made the tweaks suggested on 9/11.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

Re: [PATCH v13 00/11] iotests: Dump QCOW2 dirty bitmaps metadata

[Andrey Shinkevich]

On 20.08.2020 03:49, Eric Blake wrote:
> On 8/14/20 6:56 AM, Andrey Shinkevich wrote:
>> Dear Eric!
>>
>> Vladimir has compeated reviewing this series. I have not received any 
>> other responses to it so far.
>>
>> So, is it good for pull request now? Would you please consider taking 
>> this series as you did it with the Vladimir's related one?
>
> I've spent some time playing with this; I have now queued it on my 
> bitmaps tree, and will be posting a pull request as soon as Paolo's 
> meson changes settle.  I also made the tweaks suggested on 9/11.
>

Sounds good, thank you so much, Eric. I appreciate.

Andrey