[RFC 2/6] migration: migrate 'inc' command option is deprecated.

[Juan Quintela]

Use 'migrate_set_parameter block_incremental true' instead.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 docs/about/deprecated.rst |  7 +++++++
 qapi/migration.json       | 11 +++++++++--
 migration/migration.c     |  5 +++++
 3 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index e1aa0eafc8..c75a3a8f5a 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -433,3 +433,10 @@ Migration
 ``skipped`` field in Migration stats has been deprecated.  It hasn't
 been used for more than 10 years.
 
+``inc`` migrate command option (since 8.1)
+''''''''''''''''''''''''''''''''''''''''''
+
+The new way to modify migration is using migration parameters.
+``inc`` functionality can be acchieved using
+``migrate_set_parameter block-incremental true``.
+
diff --git a/qapi/migration.json b/qapi/migration.json
index bcae193733..4ee28df6da 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1424,13 +1424,19 @@
 #
 # @blk: do block migration (full disk copy)
 #
-# @inc: incremental disk copy migration
+# @inc: incremental disk copy migration.  This option is deprecated.
+#    Use 'migrate_set_parameter block-incremetantal true' instead.
 #
 # @detach: this argument exists only for compatibility reasons and is
 #     ignored by QEMU
 #
 # @resume: resume one paused migration, default "off". (since 3.0)
 #
+# Features:
+#
+# @deprecated: option @inc is better set with
+#     'migrate_set_parameter block-incremental true'.
+#
 # Returns: nothing on success
 #
 # Since: 0.14
@@ -1452,7 +1458,8 @@
 # <- { "return": {} }
 ##
 { 'command': 'migrate',
-  'data': {'uri': 'str', '*blk': 'bool', '*inc': 'bool',
+  'data': {'uri': 'str', '*blk': 'bool',
+           '*inc': { 'type': 'bool', 'features': ['deprecated'] },
            '*detach': 'bool', '*resume': 'bool' } }
 
 ##
diff --git a/migration/migration.c b/migration/migration.c
index dc05c6f6ea..7ebce7c7bf 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1544,6 +1544,11 @@ static bool migrate_prepare(MigrationState *s, bool blk, 
bool blk_inc,
 {
     Error *local_err = NULL;
 
+    if (blk_inc) {
+        warn_report("-inc migrate option is deprecated, use"
+                    "'migrate_set_parameter block-incremental true' instead.");
+    }
+
     if (resume) {
         if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
             error_setg(errp, "Cannot resume if there is no "
-- 
2.40.1