migration: Deprecate zero-blocks capability
The zero-blocks capability was meant to be used along with the block
migration, which has been removed already in commit eef0bae3a7
("migration: Remove block migration").
Setting zero-blocks is currently a noop, but the outright removal of
the capability would cause and error in case some users are still
setting it. Put the capability through the deprecation process.
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Peter Xu <peterx@redhat.com>
Link: https://lore.kernel.org/r/20240919134626.166183-4-dave@treblig.org
Signed-off-by: Peter Xu <peterx@redhat.com>
diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index c02bbb6..33ce4f9 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -467,3 +467,9 @@
deprecated in favor of explicitly using the ``file:`` URI with the
file descriptor being passed as an ``fdset``. Refer to the ``add-fd``
command documentation for details on the ``fdset`` usage.
+
+``zero-blocks`` capability (since 9.2)
+''''''''''''''''''''''''''''''''''''''
+
+The ``zero-blocks`` capability was part of the block migration which
+doesn't exist anymore since it was removed in QEMU v9.1.
diff --git a/migration/options.c b/migration/options.c
index 6f54998..ad8d698 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -450,6 +450,10 @@
ERRP_GUARD();
MigrationIncomingState *mis = migration_incoming_get_current();
+ if (new_caps[MIGRATION_CAPABILITY_ZERO_BLOCKS]) {
+ warn_report("zero-blocks capability is deprecated");
+ }
+
#ifndef CONFIG_REPLICATION
if (new_caps[MIGRATION_CAPABILITY_X_COLO]) {
error_setg(errp, "QEMU compiled without replication module"
diff --git a/qapi/migration.json b/qapi/migration.json
index b66cccf..3af6aa1 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -479,11 +479,14 @@
# Features:
#
# @unstable: Members @x-colo and @x-ignore-shared are experimental.
+# @deprecated: Member @zero-blocks is deprecated as being part of
+# block migration which was already removed.
#
# Since: 1.2
##
{ 'enum': 'MigrationCapability',
- 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
+ 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge',
+ { 'name': 'zero-blocks', 'features': [ 'deprecated' ] },
'events', 'postcopy-ram',
{ 'name': 'x-colo', 'features': [ 'unstable' ] },
'release-ram',