Bugfix: Handle error if VM Generation ID device not present

This was crashing due to NULL-pointer dereference

QMP Test case:
==============

(QEMU) query-vm-generation-id
{"error": {"class": "GenericError", "desc": "VM Generation ID device not
found"}}

HMP Test case:
==============
virsh # qemu-monitor-command --hmp 3 info vm-generation-id
VM Generation ID device not found

Signed-off-by: Ben Warren <ben@skyportsystems.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/hmp.c b/hmp.c
index 261843f7a2..edb8970461 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2608,9 +2608,11 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
 
 void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict)
 {
-    GuidInfo *info = qmp_query_vm_generation_id(NULL);
+    Error *err = NULL;
+    GuidInfo *info = qmp_query_vm_generation_id(&err);
     if (info) {
         monitor_printf(mon, "%s\n", info->guid);
     }
+    hmp_handle_error(mon, &err);
     qapi_free_GuidInfo(info);
 }