From 371d312300251c0dc24522607b06b7e47e760b53 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Fri, 13 Mar 2020 12:34:32 +0000
Subject: [PATCH 12/20] block: Versioned x-blockdev-reopen API with feature
 flag

RH-Author: Kevin Wolf <kwolf@redhat.com>
Message-id: <20200313123439.10548-7-kwolf@redhat.com>
Patchwork-id: 94283
O-Subject: [RHEL-AV-8.2.0 qemu-kvm PATCH v2 06/13] block: Versioned x-blockdev-reopen API with feature flag
Bugzilla: 1790482 1805143
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: John Snow <jsnow@redhat.com>
RH-Acked-by: Daniel P. Berrange <berrange@redhat.com>
RH-Acked-by: Peter Krempa <pkrempa@redhat.com>

x-blockdev-reopen is still considered unstable upstream. libvirt needs
(a small subset of) it for incremental backups, though.

Add a downstream-only feature flag that effectively makes this a
versioned interface. As long as the feature is present, we promise that
we won't change the interface incompatibly. Incompatible changes to the
command will require us to drop the feature flag (and possibly introduce
a new one if the new version is still not stable upstream).

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
 qapi/block-core.json | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/qapi/block-core.json b/qapi/block-core.json
index 0cf68fe..a1e85b0 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -4202,10 +4202,17 @@
 # image does not have a default backing file name as part of its
 # metadata.
 #
+# Features:
+# @__com.redhat_rhel-av-8_2_0-api: Versioning the downstream interface while
+#                                  it's still unstable upstream. As long as
+#                                  this flag is present, this command will not
+#                                  change incompatibly.
+#
 # Since: 4.0
 ##
 { 'command': 'x-blockdev-reopen',
-  'data': 'BlockdevOptions', 'boxed': true }
+  'data': 'BlockdevOptions', 'boxed': true,
+  'features': [ '__com.redhat_rhel-av-8_2_0-api' ] }
 
 ##
 # @blockdev-del:
-- 
1.8.3.1

