You have a large database which is currently in recovery, and you have no idea how long it will take. I’ve been there more than once, and this has helped me out:

SELECT der.session_id, der.command, der.status, der.percent_complete, *
FROM sys.dm_exec_requests AS der

Also, I found a nice post the other day with a query which displays time remaining on a restore. Could come in handy! Check it out here: How much longer will the SQL Server database restore take