migration, vl: start migration via qmp_migrate_incoming

Make qemu_start_incoming_migration local to migration/migration.c.
By using the runstate instead of a separate flag, vl need not do
anything to setup deferred incoming migration.

qmp_migrate_incoming also does not need the deferred_incoming flag
anymore, because "-incoming PROTOCOL" will clear the "once" flag
before the main loop starts.  Therefore, later invocations of
the migrate-incoming command will fail with the existing
"The incoming migration has already been started" error message.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/migration/misc.h

@@ -58,7 +58,6 @@ void dump_vmstate_json_to_file(FILE *out_fp);
 /* migration/migration.c */
 void migration_object_init(void);
 void migration_shutdown(void);
-void qemu_start_incoming_migration(const char *uri, Error **errp);
 bool migration_is_idle(void);
 bool migration_is_active(MigrationState *);
 void add_migration_state_change_notifier(Notifier *notify);

migration/migration.c

@@ -118,8 +118,6 @@
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
 
-static bool deferred_incoming;
-
 /* Messages sent on the return path from destination to source */
 enum mig_rp_message_type {
     MIG_RP_MSG_INVALID = 0,  /* Must be 0 */
@@ -275,19 +273,6 @@ static bool migrate_late_block_activate(void)
         MIGRATION_CAPABILITY_LATE_BLOCK_ACTIVATE];
 }
 
-/*
- * Called on -incoming with a defer: uri.
- * The migration can be started later after any parameters have been
- * changed.
- */
-static void deferred_incoming_migration(Error **errp)
-{
-    if (deferred_incoming) {
-        error_setg(errp, "Incoming migration already deferred");
-    }
-    deferred_incoming = true;
-}
-
 /*
  * Send a message on the return channel back to the source
  * of the migration.
@@ -429,16 +414,14 @@ void migrate_add_address(SocketAddress *address)
     addrs->value = QAPI_CLONE(SocketAddress, address);
 }
 
-void qemu_start_incoming_migration(const char *uri, Error **errp)
+static void qemu_start_incoming_migration(const char *uri, Error **errp)
 {
     const char *p = NULL;
 
     qapi_event_send_migration(MIGRATION_STATUS_SETUP);
-    if (!strcmp(uri, "defer")) {
+    if (strstart(uri, "tcp:", &p) ||
-        deferred_incoming_migration(errp);
+        strstart(uri, "unix:", NULL) ||
-    } else if (strstart(uri, "tcp:", &p) ||
+        strstart(uri, "vsock:", NULL)) {
-               strstart(uri, "unix:", NULL) ||
-               strstart(uri, "vsock:", NULL)) {
         socket_start_incoming_migration(p ? p : uri, errp);
 #ifdef CONFIG_RDMA
     } else if (strstart(uri, "rdma:", &p)) {
@@ -1988,14 +1971,14 @@ void qmp_migrate_incoming(const char *uri, Error **errp)
     Error *local_err = NULL;
     static bool once = true;
 
-    if (!deferred_incoming) {
-        error_setg(errp, "For use with '-incoming defer'");
-        return;
-    }
     if (!once) {
         error_setg(errp, "The incoming migration has already been started");
         return;
     }
+    if (!runstate_check(RUN_STATE_INMIGRATE)) {
+        error_setg(errp, "'-incoming' was not specified on the command line");
+        return;
+    }
 
     qemu_start_incoming_migration(uri, &local_err);
 

softmmu/vl.c

@@ -109,6 +109,7 @@
 #include "qapi/qapi-visit-block-core.h"
 #include "qapi/qapi-visit-ui.h"
 #include "qapi/qapi-commands-block-core.h"
+#include "qapi/qapi-commands-migration.h"
 #include "qapi/qapi-commands-run-state.h"
 #include "qapi/qapi-commands-ui.h"
 #include "qapi/qmp/qerror.h"
@@ -4556,10 +4557,12 @@ void qemu_init(int argc, char **argv, char **envp)
     }
     if (incoming) {
         Error *local_err = NULL;
-        qemu_start_incoming_migration(incoming, &local_err);
+        if (strcmp(incoming, "defer") != 0) {
-        if (local_err) {
+            qmp_migrate_incoming(incoming, &local_err);
-            error_reportf_err(local_err, "-incoming %s: ", incoming);
+            if (local_err) {
-            exit(1);
+                error_reportf_err(local_err, "-incoming %s: ", incoming);
+                exit(1);
+            }
         }
     } else if (autostart) {
         vm_start();