From 13a626395dc1a35e7a7ab0a501a83c5647e3267a Mon Sep 17 00:00:00 2001
From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Wed, 25 Oct 2017 18:28:32 +0200
Subject: [PATCH 13/19] migration: Add 'pause-before-switchover' capability

RH-Author: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-id: <20171025182838.31829-2-dgilbert@redhat.com>
Patchwork-id: 77435
O-Subject: [RHV-7.5 qemu-kvm-rhev PATCH 1/7] migration: Add 'pause-before-switchover' capability
Bugzilla: 1497120
RH-Acked-by: Peter Xu <peterx@redhat.com>
RH-Acked-by: Juan Quintela <quintela@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

When 'pause-before-switchover' is enabled, the outgoing migration
will pause before invalidating the block devices and serializing
the device state.
At this point the management layer gets the chance to clean up any
device jobs or other device users before the migration completes.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
(cherry picked from commit 93fbd0314ec060ffaf90169a06d5737fa97ffb25)
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:
        migration/migration.c
	migration/migration.h
           Differences with other flags added
	qapi/migration.json
           Still in qapi-schema.json for us
---
 migration/migration.c | 10 ++++++++++
 migration/migration.h |  1 +
 qapi-schema.json      |  5 ++++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/migration/migration.c b/migration/migration.c
index c7b4d3d..d4356a4 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1426,6 +1426,16 @@ bool migrate_use_events(void)
     return s->enabled_capabilities[MIGRATION_CAPABILITY_EVENTS];
 }
 
+bool migrate_pause_before_switchover(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->enabled_capabilities[
+        MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER];
+}
+
 int migrate_use_xbzrle(void)
 {
     MigrationState *s;
diff --git a/migration/migration.h b/migration/migration.h
index 8771ab0..2eebad8 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -170,6 +170,7 @@ bool migrate_postcopy_ram(void);
 bool migrate_zero_blocks(void);
 
 bool migrate_auto_converge(void);
+bool migrate_pause_before_switchover(void);
 
 int migrate_use_xbzrle(void);
 int64_t migrate_xbzrle_cache_size(void);
diff --git a/qapi-schema.json b/qapi-schema.json
index 0591d9d..9b9ec9a 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -919,12 +919,15 @@
 # @return-path: If enabled, migration will use the return path even
 #               for precopy. (since 2.10)
 #
+# @pause-before-switchover: Pause outgoing migration before serialising device
+#          state and before disabling block IO (since 2.11)
+#
 # Since: 1.2
 ##
 { 'enum': 'MigrationCapability',
   'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks',
            'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram',
-           'block', 'return-path' ] }
+           'block', 'return-path', 'pause-before-switchover' ] }
 
 ##
 # @MigrationCapabilityStatus:
-- 
1.8.3.1