When "to have" is the main verb you normally use the auxiliary "do" when asking a question.
Do you have....?
Simple subject verb inversion in a question is used with the verb "to be" and the modal verbs. Howeve,it is also used sometimes with the verb "to have" when it signifies general possession. It can sound very formal and old fashioned, but it is grammatically correct. Being Canadian I sometimes use have in this way.
Have you any idea what it means?
Have you any younger sisters or brothers?
Have you a quart of milk I could borrow?