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, 1 insertions, 0 deletions

diff --git a/hw/acpi/vmgenid.c b/hw/acpi/vmgenid.c
index 744f2847da..7a3ad17d66 100644
--- a/hw/acpi/vmgenid.c
+++ b/hw/acpi/vmgenid.c
@@ -248,6 +248,7 @@ GuidInfo *qmp_query_vm_generation_id(Error **errp)
     Object *obj = find_vmgenid_dev();
 
     if (!obj) {
+        error_setg(errp, "VM Generation ID device not found");
         return NULL;
     }
     vms = VMGENID(obj);