[Qemu-devel] [PATCH COLO-Frame v9 31/32] COLO: Add block replication into colo process

[zhanghailiang]

From: Wen Congyang <address@hidden>

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: Yang Hongyang <address@hidden>
Signed-off-by: Li Zhijian <address@hidden>
---
 migration/colo.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 trace-events     |  2 ++
 2 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/migration/colo.c b/migration/colo.c
index fdbda79..d7a14ba 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -21,6 +21,7 @@
 #include "qapi-event.h"
 #include "qmp-commands.h"
 #include "qapi-types.h"
+#include "block/block_int.h"
 
 /*
  * The delay time before qemu begin the procedure of default failover 
treatment.
@@ -64,6 +65,7 @@ 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.
@@ -81,6 +83,12 @@ static void secondary_vm_do_failover(void)
     migrate_set_state(&mis->state, MIGRATION_STATUS_COLO,
                       MIGRATION_STATUS_COMPLETED);
 
+    bdrv_stop_replication_all(true, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+    trace_colo_stop_block_replication("failover");
+
     if (!autostart) {
         error_report("\"-S\" qemu option will be ignored in secondary side");
         /* recover runstate to normal migration finish state */
@@ -111,6 +119,7 @@ static void primary_vm_do_failover(void)
 {
     MigrationState *s = migrate_get_current();
     int old_state;
+    Error *local_err = NULL;
 
     if (s->state != MIGRATION_STATUS_FAILED) {
         migrate_set_state(&s->state, MIGRATION_STATUS_COLO,
@@ -126,6 +135,12 @@ static void primary_vm_do_failover(void)
 
     qemu_bh_schedule(s->cleanup_bh);
 
+    bdrv_stop_replication_all(true, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+    trace_colo_stop_block_replication("failover");
+
     vm_start();
 
     old_state = failover_set_state(FAILOVER_STATUS_HANDLING,
@@ -215,6 +230,7 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     int colo_shutdown, ret;
     size_t size;
     QEMUFile *trans = NULL;
+    Error *local_err = NULL;
 
     ret = colo_ctl_put(s->to_dst_file, COLO_CMD_CHECKPOINT_REQUEST, 0);
     if (ret < 0) {
@@ -252,6 +268,16 @@ static int colo_do_checkpoint_transaction(MigrationState 
*s,
         goto out;
     }
 
+    /* we call this api although this may do nothing on primary side */
+    qemu_mutex_lock_iothread();
+    bdrv_do_checkpoint_all(&local_err);
+    qemu_mutex_unlock_iothread();
+    if (local_err) {
+        error_report_err(local_err);
+        ret = -1;
+        goto out;
+    }
+
     ret = colo_ctl_put(s->to_dst_file, COLO_CMD_VMSTATE_SEND, 0);
     if (ret < 0) {
         goto out;
@@ -294,6 +320,10 @@ static int colo_do_checkpoint_transaction(MigrationState 
*s,
     }
 
     if (colo_shutdown) {
+        qemu_mutex_lock_iothread();
+        bdrv_stop_replication_all(false, NULL);
+        trace_colo_stop_block_replication("shutdown");
+        qemu_mutex_unlock_iothread();
         colo_ctl_put(s->to_dst_file, COLO_CMD_GUEST_SHUTDOWN, 0);
         qemu_fflush(s->to_dst_file);
         colo_shutdown_requested = 0;
@@ -339,6 +369,7 @@ static void *colo_thread(void *opaque)
     int64_t current_time, checkpoint_time = qemu_clock_get_ms(QEMU_CLOCK_HOST);
     int64_t error_time;
     int fd, ret = 0;
+    Error *local_err = NULL;
 
     failover_init_state();
 
@@ -377,6 +408,14 @@ static void *colo_thread(void *opaque)
     }
 
     qemu_mutex_lock_iothread();
+    /* start block replication */
+    bdrv_start_replication_all(REPLICATION_MODE_PRIMARY, &local_err);
+    if (local_err) {
+        qemu_mutex_unlock_iothread();
+        error_report_err(local_err);
+        goto out;
+    }
+    trace_colo_start_block_replication();
     vm_start();
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("stop", "run");
@@ -507,6 +546,8 @@ static int colo_wait_handle_cmd(QEMUFile *f, int 
*checkpoint_request)
     case COLO_CMD_GUEST_SHUTDOWN:
         qemu_mutex_lock_iothread();
         vm_stop_force_state(RUN_STATE_COLO);
+        bdrv_stop_replication_all(false, NULL);
+        trace_colo_stop_block_replication("shutdown");
         qemu_system_shutdown_request_core();
         qemu_mutex_unlock_iothread();
         /* the main thread will exit and termiante the whole
@@ -538,6 +579,7 @@ void *colo_process_incoming_thread(void *opaque)
     int  total_size;
     int64_t error_time, current_time;
     int fd, ret = 0;
+    Error *local_err = NULL;
 
     migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
                       MIGRATION_STATUS_COLO);
@@ -573,6 +615,16 @@ void *colo_process_incoming_thread(void *opaque)
         goto out;
     }
 
+    qemu_mutex_lock_iothread();
+    /* start block replication */
+    bdrv_start_replication_all(REPLICATION_MODE_SECONDARY, &local_err);
+    qemu_mutex_unlock_iothread();
+    if (local_err) {
+        error_report_err(local_err);
+        goto out;
+    }
+    trace_colo_start_block_replication();
+
     ret = colo_ctl_put(mis->to_src_file, COLO_CMD_CHECKPOINT_READY, 0);
     if (ret < 0) {
         goto out;
@@ -647,8 +699,15 @@ void *colo_process_incoming_thread(void *opaque)
             goto out;
         }
 
-        vmstate_loading = false;
+        /* discard colo disk buffer */
+        bdrv_do_checkpoint_all(&local_err);
         qemu_mutex_unlock_iothread();
+        if (local_err) {
+            vmstate_loading = false;
+            goto out;
+        }
+
+        vmstate_loading = false;
 
         if (failover_get_state() == FAILOVER_STATUS_RELAUNCH) {
             failover_set_state(FAILOVER_STATUS_RELAUNCH, FAILOVER_STATUS_NONE);
diff --git a/trace-events b/trace-events
index cf378ec..d3ba02d 100644
--- a/trace-events
+++ b/trace-events
@@ -1477,6 +1477,8 @@ colo_vm_state_change(const char *old, const char *new) 
"Change '%s' => '%s'"
 colo_ctl_put(const char *msg) "Send '%s'"
 colo_ctl_get(const char *msg) "Receive '%s'"
 colo_failover_set_state(int new_state) "new state %d"
+colo_start_block_replication(void) "Block replication is started"
+colo_stop_block_replication(const char *reason) "Block replication is 
stopped(reason: '%s')"
 
 # kvm-all.c
 kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
-- 
1.8.3.1