If switch doesn't show a spanning tree instance for vlan 1 that means you don't meet the conditions I mentioned above. You can use this command to check if you have a spanning tree instance for vlan 1: In short you need to have a spanning tree instance for vlan 1. Now you also need to make sure that there is an access port that is assigned to vlan 1 and it should be in up state or a trunk port in up state. This is what you need to create an svi for vlan 1: we know that vlan 1 can't be removed from cisco switches, so I am not going to ask you to check if you have vlan 1 configured. I am not sure if SVIs are supported in GNS3, but can't say for sure.
