honor -S on incoming migration

-S is not honored by qemu on incoming migration.  If a domain is migrated
while paused, thus, it will start running on the remote machine; this
is wrong.

Given the trivial patch to fix this, it looks more like a thinko
than anything else, probably dating back to the qemu-kvm merge.
The interesting part is that the -S mechanism was in fact *used* when
migrating (setting autostart = 0) and the incoming migration code was
starting the VM at the end of the migration.

Since I was removing the vm_start from there, I also corrected a related
imprecision.  The code was doing a vm_stop "just in case", but we can
be sure that the VM is not running---the vm_start call in vl.c has not
been reached yet.  So the vm_stop is removed together with the vm_start.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

migration-exec.c

@@ -113,7 +113,6 @@ static void exec_accept_incoming_migration(void *opaque)
     QEMUFile *f = opaque;
     int ret;
 
-    vm_stop(0); /* just in case */
     ret = qemu_loadvm_state(f);
     if (ret < 0) {
         fprintf(stderr, "load of migration failed\n");
@@ -123,7 +122,6 @@ static void exec_accept_incoming_migration(void *opaque)
     dprintf("successfully loaded vm state\n");
     /* we've successfully migrated, close the fd */
     qemu_set_fd_handler2(qemu_popen_fd(f), NULL, NULL, NULL, NULL);
-    vm_start();
 
 err:
     qemu_fclose(f);

migration-tcp.c

@@ -159,7 +159,6 @@ static void tcp_accept_incoming_migration(void *opaque)
         goto out;
     }
 
-    vm_stop(0); /* just in case */
     ret = qemu_loadvm_state(f);
     if (ret < 0) {
         fprintf(stderr, "load of migration failed\n");
@@ -172,8 +171,6 @@ static void tcp_accept_incoming_migration(void *opaque)
     qemu_set_fd_handler2(s, NULL, NULL, NULL, NULL);
     close(s);
 
-    vm_start();
-
 out_fopen:
     qemu_fclose(f);
 out:

vl.c

@@ -5721,10 +5721,8 @@ int main(int argc, char **argv, char **envp)
     if (loadvm)
         do_loadvm(loadvm);
 
-    if (incoming) {
+    if (incoming)
-        autostart = 0; /* fixme how to deal with -daemonize */
         qemu_start_incoming_migration(incoming);
-    }
 
     if (autostart)
         vm_start();