migration: unfold rest of migrate_fd_put_ready() into thread

This will allow us finer control in next patches.
Signed-off-by: NJuan Quintela <quintela@redhat.com>
Reviewed-by: NReviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: NPaolo Bonzini <pbonzini@redhat.com>

migration.c

@@ -662,54 +662,6 @@ static int64_t buffered_get_rate_limit(void *opaque)
     return s->xfer_limit;
 }
 
-static bool migrate_fd_put_ready(MigrationState *s, uint64_t max_size)
-{
-    int ret;
-    uint64_t pending_size;
-    bool last_round = false;
-
-    qemu_mutex_lock_iothread();
-    DPRINTF("iterate\n");
-    pending_size = qemu_savevm_state_pending(s->file, max_size);
-    DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
-    if (pending_size >= max_size) {
-        ret = qemu_savevm_state_iterate(s->file);
-        if (ret < 0) {
-            migrate_fd_error(s);
-        }
-    } else {
-        int old_vm_running = runstate_is_running();
-        int64_t start_time, end_time;
-
-        DPRINTF("done iterating\n");
-        start_time = qemu_get_clock_ms(rt_clock);
-        qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
-        if (old_vm_running) {
-            vm_stop(RUN_STATE_FINISH_MIGRATE);
-        } else {
-            vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
-        }
-
-        if (qemu_savevm_state_complete(s->file) < 0) {
-            migrate_fd_error(s);
-        } else {
-            migrate_fd_completed(s);
-        }
-        end_time = qemu_get_clock_ms(rt_clock);
-        s->total_time = end_time - s->total_time;
-        s->downtime = end_time - start_time;
-        if (s->state != MIG_STATE_COMPLETED) {
-            if (old_vm_running) {
-                vm_start();
-            }
-        }
-        last_round = true;
-    }
-    qemu_mutex_unlock_iothread();
-
-    return last_round;
-}
-
 static void *buffered_file_thread(void *opaque)
 {
     MigrationState *s = opaque;
@@ -730,6 +682,7 @@ static void *buffered_file_thread(void *opaque)
 
     while (true) {
         int64_t current_time = qemu_get_clock_ms(rt_clock);
+        uint64_t pending_size;
 
         qemu_mutex_lock_iothread();
         if (s->state != MIG_STATE_ACTIVE) {
@@ -741,6 +694,46 @@ static void *buffered_file_thread(void *opaque)
             qemu_mutex_unlock_iothread();
             break;
         }
+        if (s->bytes_xfer < s->xfer_limit) {
+            DPRINTF("iterate\n");
+            pending_size = qemu_savevm_state_pending(s->file, max_size);
+            DPRINTF("pending size %lu max %lu\n", pending_size, max_size);
+            if (pending_size >= max_size) {
+                ret = qemu_savevm_state_iterate(s->file);
+                if (ret < 0) {
+                    qemu_mutex_unlock_iothread();
+                    break;
+                }
+            } else {
+                int old_vm_running = runstate_is_running();
+                int64_t start_time, end_time;
+
+                DPRINTF("done iterating\n");
+                start_time = qemu_get_clock_ms(rt_clock);
+                qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);
+                if (old_vm_running) {
+                    vm_stop(RUN_STATE_FINISH_MIGRATE);
+                } else {
+                    vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);
+                }
+                ret = qemu_savevm_state_complete(s->file);
+                if (ret < 0) {
+                    qemu_mutex_unlock_iothread();
+                    break;
+                } else {
+                    migrate_fd_completed(s);
+                }
+                end_time = qemu_get_clock_ms(rt_clock);
+                s->total_time = end_time - s->total_time;
+                s->downtime = end_time - start_time;
+                if (s->state != MIG_STATE_COMPLETED) {
+                    if (old_vm_running) {
+                        vm_start();
+                    }
+                }
+                last_round = true;
+            }
+        }
         qemu_mutex_unlock_iothread();
         if (current_time >= initial_time + BUFFER_DELAY) {
             uint64_t transferred_bytes = s->bytes_xfer;
@@ -763,12 +756,6 @@ static void *buffered_file_thread(void *opaque)
         if (ret < 0) {
             break;
         }
-
-        DPRINTF("file is ready\n");
-        if (s->bytes_xfer < s->xfer_limit) {
-            DPRINTF("notifying client\n");
-            last_round = migrate_fd_put_ready(s, max_size);
-        }
     }
 
 out: