Merge remote-tracking branch 'quintela/thread.next' into staging

# By Juan Quintela (7) and Paolo Bonzini (6)
# Via Juan Quintela
* quintela/thread.next:
  migration: remove argument to qemu_savevm_state_cancel
  migration: Only go to the iterate stage if there is anything to send
  migration: unfold rest of migrate_fd_put_ready() into thread
  migration: move exit condition to migration thread
  migration: Add buffered_flush error handling
  migration: move beginning stage to the migration thread
  qemu-file: Only set last_error if it is not already set
  migration: fix off-by-one in buffered_rate_limit
  migration: remove double call to migrate_fd_close
  migration: make function static
  use XFER_LIMIT_RATIO consistently
  Protect migration_bitmap_sync() with the ramlist lock
  Unlock ramlist lock also in error case

5 files changed, 81 insertions, 91 deletions

diff --git a/arch_init.c b/arch_init.c
index 86f85443d7..dada6ded1a 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -642,12 +642,13 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
         i++;
     }
 
+    qemu_mutex_unlock_ramlist();
+
     if (ret < 0) {
         bytes_transferred += total_sent;
         return ret;
     }
 
-    qemu_mutex_unlock_ramlist();
     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);
     total_sent += 8;
     bytes_transferred += total_sent;
@@ -657,9 +658,8 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
 
 static int ram_save_complete(QEMUFile *f, void *opaque)
 {
-    migration_bitmap_sync();
-
     qemu_mutex_lock_ramlist();
+    migration_bitmap_sync();
 
     /* try transferring iterative blocks of memory */
 
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 2d5b630cce..a8c9639732 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -54,7 +54,6 @@ struct MigrationState
     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
     int64_t xbzrle_cache_size;
     bool complete;
-    bool first_time;
 };
 
 void process_incoming_migration(QEMUFile *f);
@@ -87,8 +86,6 @@ void migrate_fd_error(MigrationState *s);
 
 void migrate_fd_connect(MigrationState *s);
 
-ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data,
-                              size_t size);
 int migrate_fd_close(MigrationState *s);
 
 void add_migration_state_change_notifier(Notifier *notify);
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 6599617def..337ce7df0c 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -77,7 +77,7 @@ int qemu_savevm_state_begin(QEMUFile *f,
                             const MigrationParams *params);
 int qemu_savevm_state_iterate(QEMUFile *f);
 int qemu_savevm_state_complete(QEMUFile *f);
-void qemu_savevm_state_cancel(QEMUFile *f);
+void qemu_savevm_state_cancel(void);
 uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
 int qemu_loadvm_state(QEMUFile *f);
 
diff --git a/migration.c b/migration.c
index c69e864fcd..77c1971b77 100644
--- a/migration.c
+++ b/migration.c
@@ -302,8 +302,8 @@ static void migrate_fd_completed(MigrationState *s)
     notifier_list_notify(&migration_state_notifiers, s);
 }
 
-ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data,
-                              size_t size)
+static ssize_t migrate_fd_put_buffer(MigrationState *s, const void *data,
+                                     size_t size)
 {
     ssize_t ret;
 
@@ -330,7 +330,7 @@ static void migrate_fd_cancel(MigrationState *s)
 
     s->state = MIG_STATE_CANCELLED;
     notifier_list_notify(&migration_state_notifiers, s);
-    qemu_savevm_state_cancel(s->file);
+    qemu_savevm_state_cancel();
 
     migrate_fd_cleanup(s);
 }
@@ -605,7 +605,6 @@ static int buffered_close(void *opaque)
     if (ret >= 0) {
         ret = ret2;
     }
-    ret = migrate_fd_close(s);
     s->complete = true;
     return ret;
 }
@@ -633,7 +632,7 @@ static int buffered_rate_limit(void *opaque)
         return ret;
     }
 
-    if (s->bytes_xfer > s->xfer_limit) {
+    if (s->bytes_xfer >= s->xfer_limit) {
         return 1;
     }
 
@@ -650,7 +649,7 @@ static int64_t buffered_set_rate_limit(void *opaque, int64_t new_rate)
         new_rate = SIZE_MAX;
     }
 
-    s->xfer_limit = new_rate / 10;
+    s->xfer_limit = new_rate / XFER_LIMIT_RATIO;
 
 out:
     return s->xfer_limit;
@@ -663,84 +662,79 @@ 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)
+static void *buffered_file_thread(void *opaque)
 {
-    int ret;
-    uint64_t pending_size;
+    MigrationState *s = opaque;
+    int64_t initial_time = qemu_get_clock_ms(rt_clock);
+    int64_t max_size = 0;
     bool last_round = false;
+    int ret;
 
     qemu_mutex_lock_iothread();
-    if (s->state != MIG_STATE_ACTIVE) {
-        DPRINTF("put_ready returning because of non-active state\n");
+    DPRINTF("beginning savevm\n");
+    ret = qemu_savevm_state_begin(s->file, &s->params);
+    if (ret < 0) {
+        DPRINTF("failed, %d\n", ret);
         qemu_mutex_unlock_iothread();
-        return false;
-    }
-    if (s->first_time) {
-        s->first_time = false;
-        DPRINTF("beginning savevm\n");
-        ret = qemu_savevm_state_begin(s->file, &s->params);
-        if (ret < 0) {
-            DPRINTF("failed, %d\n", ret);
-            migrate_fd_error(s);
-            qemu_mutex_unlock_iothread();
-            return false;
-        }
-    }
-
-    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;
+        goto out;
     }
     qemu_mutex_unlock_iothread();
 
-    return last_round;
-}
-
-static void *buffered_file_thread(void *opaque)
-{
-    MigrationState *s = opaque;
-    int64_t initial_time = qemu_get_clock_ms(rt_clock);
-    int64_t max_size = 0;
-    bool last_round = false;
-
     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) {
+            DPRINTF("put_ready returning because of non-active state\n");
+            qemu_mutex_unlock_iothread();
+            break;
+        }
         if (s->complete) {
+            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 && 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;
             uint64_t time_spent = current_time - initial_time;
@@ -758,17 +752,16 @@ static void *buffered_file_thread(void *opaque)
             /* usleep expects microseconds */
             g_usleep((initial_time + BUFFER_DELAY - current_time)*1000);
         }
-        if (buffered_flush(s) < 0) {
+        ret = buffered_flush(s);
+        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:
+    if (ret < 0) {
+        migrate_fd_error(s);
+    }
     g_free(s->buffer);
     return NULL;
 }
@@ -790,8 +783,6 @@ void migrate_fd_connect(MigrationState *s)
     s->buffer_size = 0;
     s->buffer_capacity = 0;
 
-    s->first_time = true;
-
     s->xfer_limit = s->bandwidth_limit / XFER_LIMIT_RATIO;
     s->complete = false;
 
diff --git a/savevm.c b/savevm.c
index d9ff1d9b72..304d1effe5 100644
--- a/savevm.c
+++ b/savevm.c
@@ -419,7 +419,9 @@ int qemu_file_get_error(QEMUFile *f)
 
 static void qemu_file_set_error(QEMUFile *f, int ret)
 {
-    f->last_error = ret;
+    if (f->last_error == 0) {
+        f->last_error = ret;
+    }
 }
 
 /** Flushes QEMUFile buffer
@@ -1588,13 +1590,13 @@ int qemu_savevm_state_begin(QEMUFile *f,
 
         ret = se->ops->save_live_setup(f, se->opaque);
         if (ret < 0) {
-            qemu_savevm_state_cancel(f);
+            qemu_savevm_state_cancel();
             return ret;
         }
     }
     ret = qemu_file_get_error(f);
     if (ret != 0) {
-        qemu_savevm_state_cancel(f);
+        qemu_savevm_state_cancel();
     }
 
     return ret;
@@ -1645,7 +1647,7 @@ int qemu_savevm_state_iterate(QEMUFile *f)
     }
     ret = qemu_file_get_error(f);
     if (ret != 0) {
-        qemu_savevm_state_cancel(f);
+        qemu_savevm_state_cancel();
     }
     return ret;
 }
@@ -1725,7 +1727,7 @@ uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
     return ret;
 }
 
-void qemu_savevm_state_cancel(QEMUFile *f)
+void qemu_savevm_state_cancel(void)
 {
     SaveStateEntry *se;