[Qemu-devel] [PATCH COLO-Frame v10 05/38] migration: Integrate COLO checkpoint process into migration

[zhanghailiang]

Add a migrate state: MIGRATION_STATUS_COLO, enter this migration state
after the first live migration successfully finished.

We reuse migration thread, so if colo is enabled by user, migration thread will
go into the process of colo.

Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Signed-off-by: Gonglei <address@hidden>
---
v10: Simplify process by dropping colo thread and reusing migration thread.
     (Dave's suggestion)
---
 include/migration/colo.h |  3 +++
 migration/colo.c         | 31 +++++++++++++++++++++++++++++++
 migration/migration.c    | 19 +++++++++++++++----
 qapi-schema.json         |  2 +-
 stubs/migration-colo.c   |  9 +++++++++
 trace-events             |  3 +++
 6 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/include/migration/colo.h b/include/migration/colo.h
index 9b6662d..f462f06 100644
--- a/include/migration/colo.h
+++ b/include/migration/colo.h
@@ -19,4 +19,7 @@
 bool colo_supported(void);
 void colo_info_mig_init(void);
 
+void migrate_start_colo_process(MigrationState *s);
+bool migration_in_colo_state(void);
+
 #endif
diff --git a/migration/colo.c b/migration/colo.c
index 2c40d2e..cf0ccb8 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -10,9 +10,40 @@
  * later.  See the COPYING file in the top-level directory.
  */
 
+#include "sysemu/sysemu.h"
 #include "migration/colo.h"
+#include "trace.h"
 
 bool colo_supported(void)
 {
     return true;
 }
+
+bool migration_in_colo_state(void)
+{
+    MigrationState *s = migrate_get_current();
+
+    return (s->state == MIGRATION_STATUS_COLO);
+}
+
+static void colo_process_checkpoint(MigrationState *s)
+{
+    qemu_mutex_lock_iothread();
+    vm_start();
+    qemu_mutex_unlock_iothread();
+    trace_colo_vm_state_change("stop", "run");
+
+    /*TODO: COLO checkpoint savevm loop*/
+
+    migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
+                      MIGRATION_STATUS_COMPLETED);
+}
+
+void migrate_start_colo_process(MigrationState *s)
+{
+    qemu_mutex_unlock_iothread();
+    migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
+                      MIGRATION_STATUS_COLO);
+    colo_process_checkpoint(s);
+    qemu_mutex_lock_iothread();
+}
diff --git a/migration/migration.c b/migration/migration.c
index b179464..cf83531 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -475,6 +475,10 @@ MigrationInfo *qmp_query_migrate(Error **errp)
 
         get_xbzrle_cache_stats(info);
         break;
+    case MIGRATION_STATUS_COLO:
+        info->has_status = true;
+        /* TODO: display COLO specific information (checkpoint info etc.) */
+        break;
     case MIGRATION_STATUS_COMPLETED:
         get_xbzrle_cache_stats(info);
 
@@ -793,7 +797,8 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk,
 
     if (s->state == MIGRATION_STATUS_ACTIVE ||
         s->state == MIGRATION_STATUS_SETUP ||
-        s->state == MIGRATION_STATUS_CANCELLING) {
+        s->state == MIGRATION_STATUS_CANCELLING ||
+        s->state == MIGRATION_STATUS_COLO) {
         error_setg(errp, QERR_MIGRATION_ACTIVE);
         return;
     }
@@ -1030,8 +1035,11 @@ static void migration_completion(MigrationState *s, bool 
*old_vm_running,
         goto fail;
     }
 
-    migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
-                      MIGRATION_STATUS_COMPLETED);
+    if (!migrate_colo_enabled()) {
+        migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE,
+                          MIGRATION_STATUS_COMPLETED);
+    }
+
     return;
 
 fail:
@@ -1056,6 +1064,7 @@ static void *migration_thread(void *opaque)
     int64_t max_size = 0;
     int64_t start_time = initial_time;
     bool old_vm_running = false;
+    bool enable_colo = migrate_colo_enabled();
 
     rcu_register_thread();
 
@@ -1130,7 +1139,9 @@ static void *migration_thread(void *opaque)
         }
         runstate_set(RUN_STATE_POSTMIGRATE);
     } else {
-        if (old_vm_running) {
+        if (s->state == MIGRATION_STATUS_ACTIVE && enable_colo) {
+            migrate_start_colo_process(s);
+        } else if (old_vm_running) {
             vm_start();
         }
     }
diff --git a/qapi-schema.json b/qapi-schema.json
index cb5e5fd..22251ec 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -439,7 +439,7 @@
 ##
 { 'enum': 'MigrationStatus',
   'data': [ 'none', 'setup', 'cancelling', 'cancelled',
-            'active', 'completed', 'failed' ] }
+            'active', 'completed', 'failed', 'colo' ] }
 
 ##
 # @MigrationInfo
diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
index 3d817df..acddca6 100644
--- a/stubs/migration-colo.c
+++ b/stubs/migration-colo.c
@@ -16,3 +16,12 @@ bool colo_supported(void)
 {
     return false;
 }
+
+bool migration_in_colo_state(void)
+{
+    return false;
+}
+
+void migrate_start_colo_process(MigrationState *s)
+{
+}
diff --git a/trace-events b/trace-events
index 72136b9..9cd6391 100644
--- a/trace-events
+++ b/trace-events
@@ -1497,6 +1497,9 @@ rdma_start_incoming_migration_after_rdma_listen(void) ""
 rdma_start_outgoing_migration_after_rdma_connect(void) ""
 rdma_start_outgoing_migration_after_rdma_source_init(void) ""
 
+# migration/colo.c
+colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
+
 # kvm-all.c
 kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
 kvm_vm_ioctl(int type, void *arg) "type 0x%x, arg %p"
-- 
1.8.3.1