[PATCH 2/3] migration: Remove unused zero-blocks capability

[dave]

From: "Dr. David Alan Gilbert" <dave@treblig.org>

migrate_zero_blocks is unused since
  eef0bae3a7 ("migration: Remove block migration")

Remove it.
That whole zero-blocks capability was just for old-school
block migration anyway.

Remove the capability as well.

Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
---
 migration/options.c |  8 --------
 migration/options.h |  1 -
 qapi/migration.json | 10 +---------
 3 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/migration/options.c b/migration/options.c
index 9460c5dee9..997e060612 100644
--- a/migration/options.c
+++ b/migration/options.c
@@ -177,7 +177,6 @@ Property migration_properties[] = {
     DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
     DEFINE_PROP_MIG_CAP("x-rdma-pin-all", MIGRATION_CAPABILITY_RDMA_PIN_ALL),
     DEFINE_PROP_MIG_CAP("x-auto-converge", MIGRATION_CAPABILITY_AUTO_CONVERGE),
-    DEFINE_PROP_MIG_CAP("x-zero-blocks", MIGRATION_CAPABILITY_ZERO_BLOCKS),
     DEFINE_PROP_MIG_CAP("x-events", MIGRATION_CAPABILITY_EVENTS),
     DEFINE_PROP_MIG_CAP("x-postcopy-ram", MIGRATION_CAPABILITY_POSTCOPY_RAM),
     DEFINE_PROP_MIG_CAP("x-postcopy-preempt",
@@ -339,13 +338,6 @@ bool migrate_xbzrle(void)
     return s->capabilities[MIGRATION_CAPABILITY_XBZRLE];
 }
 
-bool migrate_zero_blocks(void)
-{
-    MigrationState *s = migrate_get_current();
-
-    return s->capabilities[MIGRATION_CAPABILITY_ZERO_BLOCKS];
-}
-
 bool migrate_zero_copy_send(void)
 {
     MigrationState *s = migrate_get_current();
diff --git a/migration/options.h b/migration/options.h
index 36e7b3723f..79084eed0d 100644
--- a/migration/options.h
+++ b/migration/options.h
@@ -40,7 +40,6 @@ bool migrate_release_ram(void);
 bool migrate_return_path(void);
 bool migrate_validate_uuid(void);
 bool migrate_xbzrle(void);
-bool migrate_zero_blocks(void);
 bool migrate_zero_copy_send(void);
 
 /*
diff --git a/qapi/migration.json b/qapi/migration.json
index b66cccf107..82d0fc962e 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -389,13 +389,6 @@
 #     footprint is mlock()'d on demand or all at once.  Refer to
 #     docs/rdma.txt for usage.  Disabled by default.  (since 2.0)
 #
-# @zero-blocks: During storage migration encode blocks of zeroes
-#     efficiently.  This essentially saves 1MB of zeroes per block on
-#     the wire.  Enabling requires source and target VM to support
-#     this feature.  To enable it is sufficient to enable the
-#     capability on the source VM.  The feature is disabled by
-#     default.  (since 1.6)
-#
 # @events: generate events for each migration state change (since 2.4)
 #
 # @auto-converge: If enabled, QEMU will automatically throttle down
@@ -483,7 +476,7 @@
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
-  'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
+  'data': ['xbzrle', 'rdma-pin-all', 'auto-converge',
            'events', 'postcopy-ram',
            { 'name': 'x-colo', 'features': [ 'unstable' ] },
            'release-ram',
@@ -542,7 +535,6 @@
 #           {"state": false, "capability": "xbzrle"},
 #           {"state": false, "capability": "rdma-pin-all"},
 #           {"state": false, "capability": "auto-converge"},
-#           {"state": false, "capability": "zero-blocks"},
 #           {"state": true, "capability": "events"},
 #           {"state": false, "capability": "postcopy-ram"},
 #           {"state": false, "capability": "x-colo"}
-- 
2.46.0