We have trusted hardware or hardware protection, do we still need software protection?

Yes. Even hardware protection needs to have encryption keys hidden somewhere. The transition between trusted and untrusted areas is a good candidate for White Hawk software protection. The substantial complexity of trusted hardware makes it likely that somebody might find software bugs to enter the system. Hardware protection is from the viewpoint of the processor. It typically protects the processor from an application. Remember White Hawk Software protection is different: We protect an application from the processor (respectively its owner).