qcow2: QcowHeaderExtension print names for extension magics

Suggested-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200606081806.23897-13-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

4 files changed, 36 insertions, 21 deletions

diff --git a/tests/qemu-iotests/031.out b/tests/qemu-iotests/031.out
index 5a4beda..4b21d6a 100644
--- a/tests/qemu-iotests/031.out
+++ b/tests/qemu-iotests/031.out
@@ -25,7 +25,7 @@ refcount_order            4
 header_length             72
 
 Header extension:
-magic                     0x12345678
+magic                     0x12345678 (<unknown>)
 length                    31
 data                      'This is a test header extension'
 
@@ -53,7 +53,7 @@ refcount_order            4
 header_length             72
 
 Header extension:
-magic                     0x12345678
+magic                     0x12345678 (<unknown>)
 length                    31
 data                      'This is a test header extension'
 
@@ -81,12 +81,12 @@ refcount_order            4
 header_length             72
 
 Header extension:
-magic                     0xe2792aca
+magic                     0xe2792aca (Backing format)
 length                    11
 data                      'host_device'
 
 Header extension:
-magic                     0x12345678
+magic                     0x12345678 (<unknown>)
 length                    31
 data                      'This is a test header extension'
 
@@ -116,12 +116,12 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
 Header extension:
-magic                     0x12345678
+magic                     0x12345678 (<unknown>)
 length                    31
 data                      'This is a test header extension'
 
@@ -149,12 +149,12 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
 Header extension:
-magic                     0x12345678
+magic                     0x12345678 (<unknown>)
 length                    31
 data                      'This is a test header extension'
 
@@ -182,17 +182,17 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0xe2792aca
+magic                     0xe2792aca (Backing format)
 length                    11
 data                      'host_device'
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
 Header extension:
-magic                     0x12345678
+magic                     0x12345678 (<unknown>)
 length                    31
 data                      'This is a test header extension'
 
diff --git a/tests/qemu-iotests/036.out b/tests/qemu-iotests/036.out
index e409acf..a9bed82 100644
--- a/tests/qemu-iotests/036.out
+++ b/tests/qemu-iotests/036.out
@@ -25,7 +25,7 @@ incompatible_features     []
 compatible_features       []
 autoclear_features        [63]
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -37,7 +37,7 @@ incompatible_features     []
 compatible_features       []
 autoclear_features        []
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out
index a51ad1b..2f03cf0 100644
--- a/tests/qemu-iotests/061.out
+++ b/tests/qemu-iotests/061.out
@@ -25,7 +25,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -83,7 +83,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -139,7 +139,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -194,7 +194,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -263,7 +263,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -325,7 +325,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
@@ -354,7 +354,7 @@ refcount_order            4
 header_length             112
 
 Header extension:
-magic                     0x6803f857
+magic                     0x6803f857 (Feature table)
 length                    336
 data                      <binary>
 
diff --git a/tests/qemu-iotests/qcow2_format.py b/tests/qemu-iotests/qcow2_format.py
index 32371e4..40b5bf4 100644
--- a/tests/qemu-iotests/qcow2_format.py
+++ b/tests/qemu-iotests/qcow2_format.py
@@ -39,6 +39,12 @@ class Flags64(Qcow2Field):
         return str(bits)
 
 
+class Enum(Qcow2Field):
+
+    def __str__(self):
+        return f'{self.value:#x} ({self.mapping.get(self.value, "<unknown>")})'
+
+
 class Qcow2StructMeta(type):
 
     # Mapping from c types to python struct format
@@ -99,8 +105,17 @@ class Qcow2Struct(metaclass=Qcow2StructMeta):
 
 class QcowHeaderExtension(Qcow2Struct):
 
+    class Magic(Enum):
+        mapping = {
+            0xe2792aca: 'Backing format',
+            0x6803f857: 'Feature table',
+            0x0537be77: 'Crypto header',
+            0x23852875: 'Bitmaps',
+            0x44415441: 'Data file'
+        }
+
     fields = (
-        ('u32', '{:#x}', 'magic'),
+        ('u32', Magic, 'magic'),
         ('u32', '{}', 'length')
         # length bytes of data follows
         # then padding to next multiply of 8