[Qemu-devel] [PATCH COLO-Frame v19 20/22] COLO: Add block replication into colo process

[zhanghailiang]

Make sure master start block replication after slave's block
replication started.

Signed-off-by: zhanghailiang <address@hidden>
Signed-off-by: Wen Congyang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
Cc: Stefan Hajnoczi <address@hidden>
Cc: Kevin Wolf <address@hidden>
Cc: Max Reitz <address@hidden>
---
 migration/colo.c      | 52 +++++++++++++++++++++++++++++++++++++++++++++++++++
 migration/migration.c |  6 +++++-
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/migration/colo.c b/migration/colo.c
index b6f3cb0..ee20703 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -19,6 +19,9 @@
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "migration/failover.h"
+#include "qapi-event.h"
+#include "block/block.h"
+#include "replication.h"
 
 static bool vmstate_loading;
 
@@ -52,6 +55,7 @@ static void secondary_vm_do_failover(void)
 {
     int old_state;
     MigrationIncomingState *mis = migration_incoming_get_current();
+    Error *local_err = NULL;
 
     /* Can not do failover during the process of VM's loading VMstate, Or
      * it will break the secondary VM.
@@ -69,6 +73,11 @@ static void secondary_vm_do_failover(void)
     migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
 
+    replication_stop_all(true, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
     if (!autostart) {
         error_report("\"-S\" qemu option will be ignored in secondary side");
         /* recover runstate to normal migration finish state */
@@ -106,6 +115,7 @@ static void primary_vm_do_failover(void)
 {
     MigrationState *s = migrate_get_current();
     int old_state;
+    Error *local_err = NULL;
 
     migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
@@ -129,6 +139,12 @@ static void primary_vm_do_failover(void)
                      old_state);
         return;
     }
+
+    replication_stop_all(true, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
     /* Notify COLO thread that failover work is finished */
     qemu_sem_post(&s->colo_exit_sem);
 }
@@ -288,6 +304,15 @@ static int colo_do_checkpoint_transaction(MigrationState 
*s,
     s->params.shared = 0;
     qemu_savevm_state_header(fb);
     qemu_savevm_state_begin(fb, &s->params);
+
+    /* We call this API although this may do nothing on primary side. */
+    qemu_mutex_lock_iothread();
+    replication_do_checkpoint_all(&local_err);
+    qemu_mutex_unlock_iothread();
+    if (local_err) {
+        goto out;
+    }
+
     qemu_mutex_lock_iothread();
     qemu_savevm_state_complete_precopy(fb, false);
     qemu_mutex_unlock_iothread();
@@ -386,6 +411,12 @@ static void colo_process_checkpoint(MigrationState *s)
     object_unref(OBJECT(bioc));
 
     qemu_mutex_lock_iothread();
+    replication_start_all(REPLICATION_MODE_PRIMARY, &local_err);
+    if (local_err) {
+        qemu_mutex_unlock_iothread();
+        goto out;
+    }
+
     vm_start();
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("stop", "run");
@@ -468,6 +499,7 @@ static void colo_wait_handle_message(QEMUFile *f, int 
*checkpoint_request,
     case COLO_MESSAGE_GUEST_SHUTDOWN:
         qemu_mutex_lock_iothread();
         vm_stop_force_state(RUN_STATE_COLO);
+        replication_stop_all(false, NULL);
         qemu_system_shutdown_request_core();
         qemu_mutex_unlock_iothread();
         /*
@@ -514,6 +546,14 @@ void *colo_process_incoming_thread(void *opaque)
     fb = qemu_fopen_channel_input(QIO_CHANNEL(bioc));
     object_unref(OBJECT(bioc));
 
+    qemu_mutex_lock_iothread();
+    bdrv_invalidate_cache_all(&local_err);
+    replication_start_all(REPLICATION_MODE_SECONDARY, &local_err);
+    qemu_mutex_unlock_iothread();
+    if (local_err) {
+        goto out;
+    }
+
     colo_send_message(mis->to_src_file, COLO_MESSAGE_CHECKPOINT_READY,
                       &local_err);
     if (local_err) {
@@ -585,6 +625,18 @@ void *colo_process_incoming_thread(void *opaque)
             goto out;
         }
 
+        replication_get_error_all(&local_err);
+        if (local_err) {
+            qemu_mutex_unlock_iothread();
+            goto out;
+        }
+        /* discard colo disk buffer */
+        replication_do_checkpoint_all(&local_err);
+        if (local_err) {
+            qemu_mutex_unlock_iothread();
+            goto out;
+        }
+
         vmstate_loading = false;
         qemu_mutex_unlock_iothread();
 
diff --git a/migration/migration.c b/migration/migration.c
index db618db..9a904b8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1679,7 +1679,11 @@ static void migration_completion(MigrationState *s, int 
current_active_state,
 
         if (!ret) {
             ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
-            if (ret >= 0) {
+            /*
+             * Don't mark the image with BDRV_O_INACTIVE flag if
+             * we will go into COLO stage later.
+             */
+            if (ret >= 0 && !migrate_colo_enabled()) {
                 ret = bdrv_inactivate_all();
             }
             if (ret >= 0) {
-- 
1.8.3.1