1 files changed, 55 insertions, 34 deletions

diff --git a/migration/migration.c b/migration/migration.c
index 4228635d18..5ff7ba9d5c 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -456,10 +456,6 @@ static void qemu_start_incoming_migration(const char *uri, Error **errp)
 {
     const char *p = NULL;
 
-    if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
-        return;
-    }
-
     qapi_event_send_migration(MIGRATION_STATUS_SETUP);
     if (strstart(uri, "tcp:", &p) ||
         strstart(uri, "unix:", NULL) ||
@@ -474,7 +470,6 @@ static void qemu_start_incoming_migration(const char *uri, Error **errp)
     } else if (strstart(uri, "fd:", &p)) {
         fd_start_incoming_migration(p, errp);
     } else {
-        yank_unregister_instance(MIGRATION_YANK_INSTANCE);
         error_setg(errp, "unknown migration protocol: %s", uri);
     }
 }
@@ -2083,9 +2078,14 @@ void qmp_migrate_incoming(const char *uri, Error **errp)
         return;
     }
 
+    if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) {
+        return;
+    }
+
     qemu_start_incoming_migration(uri, &local_err);
 
     if (local_err) {
+        yank_unregister_instance(MIGRATION_YANK_INSTANCE);
         error_propagate(errp, local_err);
         return;
     }
@@ -2097,6 +2097,13 @@ void qmp_migrate_recover(const char *uri, Error **errp)
 {
     MigrationIncomingState *mis = migration_incoming_get_current();
 
+    /*
+     * Don't even bother to use ERRP_GUARD() as it _must_ always be set by
+     * callers (no one should ignore a recover failure); if there is, it's a
+     * programming error.
+     */
+    assert(errp);
+
     if (mis->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
         error_setg(errp, "Migrate recover can only be run "
                    "when postcopy is paused.");
@@ -2114,8 +2121,13 @@ void qmp_migrate_recover(const char *uri, Error **errp)
      * only re-setup the migration stream and poke existing migration
      * to continue using that newly established channel.
      */
-    yank_unregister_instance(MIGRATION_YANK_INSTANCE);
     qemu_start_incoming_migration(uri, errp);
+
+    /* Safe to dereference with the assert above */
+    if (*errp) {
+        /* Reset the flag so user could still retry */
+        qatomic_set(&mis->postcopy_recover_triggered, false);
+    }
 }
 
 void qmp_migrate_pause(Error **errp)
@@ -3665,6 +3677,39 @@ bool migration_rate_limit(void)
 }
 
 /*
+ * 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);
+        }
+        if (s->state != MIGRATION_STATUS_WAIT_UNPLUG) {
+            int timeout = 120; /* 30 seconds */
+            /*
+             * migration has been canceled
+             * but as we have started an unplug we must wait the end
+             * to be able to plug back the card
+             */
+            while (timeout-- && 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 +3755,10 @@ 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 +3866,9 @@ 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();