[Qemu-devel] [PATCH] migration: Introduce MIGRATION_STATUS_FINISHING

[Pavel Fedin <p.fedin@samsung.com>]

This status is set after vm_stop_force_state(), and is telling us that all
CPUs are stopped, and we are finishing up with the migration.

Also, call notifier_list_notify() when this status is set. This will be
necessary for ITS live migration on ARM, which will have to dump its state
into guest RAM at this point.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
---
 hmp.c                         |  1 +
 include/migration/migration.h |  1 +
 migration/migration.c         | 19 ++++++++++++++++---
 qapi-schema.json              |  4 +++-
 4 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/hmp.c b/hmp.c
index 5048eee..202768f 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1467,6 +1467,7 @@ static void hmp_migrate_status_cb(void *opaque)
 
     info = qmp_query_migrate(NULL);
     if (!info->has_status || info->status == MIGRATION_STATUS_ACTIVE ||
+        info->status == MIGRATION_STATUS_FINISHING ||
         info->status == MIGRATION_STATUS_SETUP) {
         if (info->has_disk) {
             int progress;
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 8334621..ff4bfcb 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -117,6 +117,7 @@ int migrate_fd_close(MigrationState *s);
 void add_migration_state_change_notifier(Notifier *notify);
 void remove_migration_state_change_notifier(Notifier *notify);
 bool migration_in_setup(MigrationState *);
+bool migration_in_finishing(MigrationState *);
 bool migration_has_finished(MigrationState *);
 bool migration_has_failed(MigrationState *);
 MigrationState *migrate_get_current(void);
diff --git a/migration/migration.c b/migration/migration.c
index b092f38..8f28585 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -427,6 +427,7 @@ MigrationInfo *qmp_query_migrate(Error **errp)
         info->has_total_time = false;
         break;
     case MIGRATION_STATUS_ACTIVE:
+    case MIGRATION_STATUS_FINISHING:
     case MIGRATION_STATUS_CANCELLING:
         info->has_status = true;
         info->has_total_time = true;
@@ -507,6 +508,7 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
     MigrationCapabilityStatusList *cap;
 
     if (s->state == MIGRATION_STATUS_ACTIVE ||
+        s->state == MIGRATION_STATUS_FINISHING ||
         s->state == MIGRATION_STATUS_SETUP) {
         error_setg(errp, QERR_MIGRATION_ACTIVE);
         return;
@@ -641,7 +643,8 @@ static void migrate_fd_cancel(MigrationState *s)
     do {
         old_state = s->state;
         if (old_state != MIGRATION_STATUS_SETUP &&
-            old_state != MIGRATION_STATUS_ACTIVE) {
+            old_state != MIGRATION_STATUS_ACTIVE &&
+            old_state != MIGRATION_STATUS_FINISHING) {
             break;
         }
         migrate_set_state(s, old_state, MIGRATION_STATUS_CANCELLING);
@@ -674,6 +677,11 @@ bool migration_in_setup(MigrationState *s)
     return s->state == MIGRATION_STATUS_SETUP;
 }
 
+bool migration_in_finishing(MigrationState *s)
+{
+    return s->state == MIGRATION_STATUS_FINISHING;
+}
+
 bool migration_has_finished(MigrationState *s)
 {
     return s->state == MIGRATION_STATUS_COMPLETED;
@@ -774,6 +782,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
     params.shared = has_inc && inc;
 
     if (s->state == MIGRATION_STATUS_ACTIVE ||
+        s->state == MIGRATION_STATUS_FINISHING ||
         s->state == MIGRATION_STATUS_SETUP ||
         s->state == MIGRATION_STATUS_CANCELLING) {
         error_setg(errp, QERR_MIGRATION_ACTIVE);
@@ -985,6 +994,7 @@ int64_t migrate_xbzrle_cache_size(void)
 static void migration_completion(MigrationState *s, bool *old_vm_running,
                                  int64_t *start_time)
 {
+    MigrationStatus state = MIGRATION_STATUS_ACTIVE;
     int ret;
 
     qemu_mutex_lock_iothread();
@@ -996,6 +1006,9 @@ static void migration_completion(MigrationState *s, bool *old_vm_running,
     if (!ret) {
         ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
         if (ret >= 0) {
+            state = MIGRATION_STATUS_FINISHING;
+            migrate_set_state(s, MIGRATION_STATUS_ACTIVE, state);
+            notifier_list_notify(&migration_state_notifiers, s);
             qemu_file_set_rate_limit(s->file, INT64_MAX);
             qemu_savevm_state_complete(s->file);
         }
@@ -1011,11 +1024,11 @@ static void migration_completion(MigrationState *s, bool *old_vm_running,
         goto fail;
     }
 
-    migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_COMPLETED);
+    migrate_set_state(s, state, MIGRATION_STATUS_COMPLETED);
     return;
 
 fail:
-    migrate_set_state(s, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_FAILED);
+    migrate_set_state(s, state, MIGRATION_STATUS_FAILED);
 }
 
 /* migration thread support */
diff --git a/qapi-schema.json b/qapi-schema.json
index f60be29..c6226da 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -430,6 +430,8 @@
 #
 # @active: in the process of doing migration.
 #
+# @finishing: migration is being finished, CPUs have been stopped.
+#
 # @completed: migration is finished.
 #
 # @failed: some error occurred during migration process.
@@ -439,7 +441,7 @@
 ##
 { 'enum': 'MigrationStatus',
   'data': [ 'none', 'setup', 'cancelling', 'cancelled',
-            'active', 'completed', 'failed' ] }
+            'active', 'finishing', 'completed', 'failed' ] }
 
 ##
 # @MigrationInfo
-- 
1.9.5.msysgit.0