qmp: query-block: add 'encryption_key_missing' field

Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>

block.c

@@ -2445,6 +2445,7 @@ BlockInfoList *qmp_query_block(Error **errp)
             info->value->inserted->ro = bs->read_only;
             info->value->inserted->drv = g_strdup(bs->drv->format_name);
             info->value->inserted->encrypted = bs->encrypted;
+            info->value->inserted->encryption_key_missing = bdrv_key_required(bs);
             if (bs->backing_file[0]) {
                 info->value->inserted->has_backing_file = true;
                 info->value->inserted->backing_file = g_strdup(bs->backing_file);

qapi-schema.json

@@ -402,6 +402,9 @@
 #
 # @encrypted: true if the backing device is encrypted
 #
+# @encryption_key_missing: true if the backing device is encrypted but an
+#                          valid encryption key is missing
+#
 # @bps: total throughput limit in bytes per second is specified
 #
 # @bps_rd: read throughput limit in bytes per second is specified
@@ -421,9 +424,9 @@
 { 'type': 'BlockDeviceInfo',
   'data': { 'file': 'str', 'ro': 'bool', 'drv': 'str',
             '*backing_file': 'str', 'backing_file_depth': 'int',
-            'encrypted': 'bool', 'bps': 'int', 'bps_rd': 'int',
-            'bps_wr': 'int', 'iops': 'int', 'iops_rd': 'int',
-            'iops_wr': 'int'} }
+            'encrypted': 'bool', 'encryption_key_missing': 'bool',
+            'bps': 'int', 'bps_rd': 'int', 'bps_wr': 'int',
+            'iops': 'int', 'iops_rd': 'int', 'iops_wr': 'int'} }
 
 ##
 # @BlockDeviceIoStatus: