[PATCH 1/2] migration: move wait-unplug loop to its own function

[Laurent Vivier <lvivier@redhat.com>]

The loop is used in migration_thread() and bg_migration_thread(),
so we can move it to its own function and call it from these both places.

Moreover, in migration_thread() we have a wrong state transition from
SETUP to ACTIVE while state could be WAIT_UNPLUG. This is correctly
managed in bg_migration_thread() so use this code instead.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 migration/migration.c | 54 +++++++++++++++++++++----------------------
 1 file changed, 26 insertions(+), 28 deletions(-)

diff --git a/migration/migration.c b/migration/migration.c
index 4228635d1880..3e92c405a2b6 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3664,6 +3664,28 @@ bool migration_rate_limit(void)
     return urgent;
 }
 
+/*
+ * if failover devices are present, wait they are completely
+ * unplugged
+ */
+
+static void qemu_savevm_wait_unplug(MigrationState *s, int old_state,
+                                    int new_state)
+{
+    if (qemu_savevm_state_guest_unplug_pending()) {
+        migrate_set_state(&s->state, old_state, MIGRATION_STATUS_WAIT_UNPLUG);
+
+        while (s->state == MIGRATION_STATUS_WAIT_UNPLUG &&
+               qemu_savevm_state_guest_unplug_pending()) {
+            qemu_sem_timedwait(&s->wait_unplug_sem, 250);
+        }
+
+        migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG, new_state);
+    } else {
+        migrate_set_state(&s->state, old_state, new_state);
+    }
+}
+
 /*
  * Master migration thread on the source VM.
  * It drives the migration and pumps the data down the outgoing channel.
@@ -3710,22 +3732,10 @@ static void *migration_thread(void *opaque)
 
     qemu_savevm_state_setup(s->to_dst_file);
 
-    if (qemu_savevm_state_guest_unplug_pending()) {
-        migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
-                          MIGRATION_STATUS_WAIT_UNPLUG);
-
-        while (s->state == MIGRATION_STATUS_WAIT_UNPLUG &&
-               qemu_savevm_state_guest_unplug_pending()) {
-            qemu_sem_timedwait(&s->wait_unplug_sem, 250);
-        }
-
-        migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG,
-                MIGRATION_STATUS_ACTIVE);
-    }
+    qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
+                               MIGRATION_STATUS_ACTIVE);
 
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
-    migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
-                      MIGRATION_STATUS_ACTIVE);
 
     trace_migration_thread_setup_complete();
 
@@ -3833,21 +3843,9 @@ static void *bg_migration_thread(void *opaque)
     qemu_savevm_state_header(s->to_dst_file);
     qemu_savevm_state_setup(s->to_dst_file);
 
-    if (qemu_savevm_state_guest_unplug_pending()) {
-        migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
-                          MIGRATION_STATUS_WAIT_UNPLUG);
-
-        while (s->state == MIGRATION_STATUS_WAIT_UNPLUG &&
-               qemu_savevm_state_guest_unplug_pending()) {
-            qemu_sem_timedwait(&s->wait_unplug_sem, 250);
-        }
+    qemu_savevm_wait_unplug(s, MIGRATION_STATUS_SETUP,
+                               MIGRATION_STATUS_ACTIVE);
 
-        migrate_set_state(&s->state, MIGRATION_STATUS_WAIT_UNPLUG,
-                          MIGRATION_STATUS_ACTIVE);
-    } else {
-        migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
-                MIGRATION_STATUS_ACTIVE);
-    }
     s->setup_time = qemu_clock_get_ms(QEMU_CLOCK_HOST) - setup_start;
 
     trace_migration_thread_setup_complete();
-- 
2.31.1