[Qemu-devel] [PATCH v4 4/6] qcow2: Add support for ImageInfoSpecific

[Max Reitz <mreitz@redhat.com>]

Add a new ImageInfoSpecificQCow2 type as a subtype of ImageInfoSpecific.
This contains the compatibility level as a string and an optional
lazy_refcounts boolean (optional means mandatory for compat >= 1.1 and
not available for compat == 0.10).

In qcow2_get_info, fill the BlockDriverInfo.format_specific field with
that information.

Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/qcow2.c    | 12 ++++++++++++
 qapi-schema.json | 16 ++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 7c9354c..6bc59c0 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1761,8 +1761,20 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
 static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 {
     BDRVQcowState *s = bs->opaque;
+
     bdi->cluster_size = s->cluster_size;
     bdi->vm_state_offset = qcow2_vm_state_offset(s);
+
+    bdi->format_specific = g_new0(ImageInfoSpecific, 1);
+    bdi->format_specific->kind = IMAGE_INFO_SPECIFIC_KIND_QCOW2;
+    bdi->format_specific->qcow2 = g_new0(ImageInfoSpecificQCow2, 1);
+    if (s->qcow_version == 2) {
+        bdi->format_specific->qcow2->compat = g_strdup("0.10");
+    } else if (s->qcow_version == 3) {
+        bdi->format_specific->qcow2->compat = g_strdup("1.1");
+        bdi->format_specific->qcow2->lazy_refcounts = s->use_lazy_refcounts;
+        bdi->format_specific->qcow2->has_lazy_refcounts = true;
+    }
     return 0;
 }
 
diff --git a/qapi-schema.json b/qapi-schema.json
index d4c63d9..6de32ea 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -210,6 +210,21 @@
             'vm-clock-sec': 'int', 'vm-clock-nsec': 'int' } }
 
 ##
+# @ImageInfoSpecificQCow2:
+#
+# @compat: compatibility level
+#
+# @lazy-refcounts: #optional on or off; only valid for compat >= 1.1
+#
+# Since: 1.7
+##
+{ 'type': 'ImageInfoSpecificQCow2',
+  'data': {
+      'compat': 'str',
+      '*lazy-refcounts': 'bool'
+  } }
+
+##
 # @ImageInfoSpecific:
 #
 # A discriminated record of image format specific information structures.
@@ -219,6 +234,7 @@
 
 { 'union': 'ImageInfoSpecific',
   'data': {
+      'qcow2': 'ImageInfoSpecificQCow2'
   } }
 
 ##
-- 
1.8.3.1