[Qemu-devel] [PATCH COLO-Frame v10 38/38] COLO: Add block replication into colo process

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

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

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
---
 migration/colo.c      | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++-
 migration/migration.c | 10 ---------
 trace-events          |  2 ++
 3 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/migration/colo.c b/migration/colo.c
index 25335db..cb9c6db 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -23,6 +23,7 @@
 #include "qapi-types.h"
 #include "net/filter.h"
 #include "net/net.h"
+#include "block/block_int.h"
 
 /*
  * The delay time before qemu begin the procedure of default failover treatment.
@@ -83,6 +84,7 @@ 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.
@@ -100,6 +102,12 @@ 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 */
@@ -130,6 +138,7 @@ 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,
@@ -145,6 +154,12 @@ static void primary_vm_do_failover(void)
     }
     colo_cleanup_filter_buffers();
 
+    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,
@@ -234,6 +249,7 @@ 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_COMMAND_CHECKPOINT_REQUEST, 0);
     if (ret < 0) {
@@ -271,6 +287,16 @@ 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_COMMAND_VMSTATE_SEND, 0);
     if (ret < 0) {
         goto out;
@@ -315,6 +341,10 @@ static int colo_do_checkpoint_transaction(MigrationState *s,
     filter_buffer_release_all();
 
     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_COMMAND_GUEST_SHUTDOWN, 0);
         qemu_fflush(s->to_dst_file);
         colo_shutdown_requested = 0;
@@ -359,6 +389,7 @@ static void colo_process_checkpoint(MigrationState *s)
     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();
 
@@ -403,6 +434,15 @@ static void colo_process_checkpoint(MigrationState *s)
     }
 
     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);
+        ret = -EINVAL;
+        goto out;
+    }
+    trace_colo_start_block_replication();
     vm_start();
     qemu_mutex_unlock_iothread();
     trace_colo_vm_state_change("stop", "run");
@@ -514,6 +554,8 @@ static int colo_wait_handle_cmd(QEMUFile *f, int *checkpoint_request)
     case COLO_COMMAND_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
@@ -545,6 +587,7 @@ 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);
@@ -580,6 +623,16 @@ 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_COMMAND_CHECKPOINT_READY, 0);
     if (ret < 0) {
         goto out;
@@ -655,8 +708,15 @@ 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/migration/migration.c b/migration/migration.c
index 41ec693..72a2b63 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -328,16 +328,6 @@ static void process_incoming_migration_co(void *opaque)
         exit(EXIT_FAILURE);
     }
 
-    /* Make sure all file formats flush their mutable metadata */
-    bdrv_invalidate_cache_all(&local_err);
-    if (local_err) {
-        migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE,
-                          MIGRATION_STATUS_FAILED);
-        error_report_err(local_err);
-        migrate_decompress_threads_join();
-        exit(EXIT_FAILURE);
-    }
-
     /*
      * This must happen after all error conditions are dealt with and
      * we're sure the VM is going to be running on this host.
diff --git a/trace-events b/trace-events
index 61e89c7..8ab56b5 100644
--- a/trace-events
+++ b/trace-events
@@ -1503,6 +1503,8 @@ colo_vm_state_change(const char *old, const char *new) "Change '%s' => '%s'"
 colo_ctl_put(const char *msg, uint64_t value) "Send '%s' cmd, value: %" PRIu64""
 colo_ctl_get(const char *msg) "Receive '%s' cmd"
 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