Can you setup a 2014 mac pro using a mid-2011 iMac target display mode?

When I connect the thunderbolt cable between the two and use Cmd+F2 from the iMac (running Mavericks) I get a dark grey screen with the cursor in the upper left corner. I'm unable to do anything else -- no screen to setup/configure the mac pro -- and Cmd+F2 won't return the display to the iMac.

BTW. . . this is the same color screen and cursor location i get when booting up my iMac normally just without the account login icons.

Does the Mac Pro already need to be setup before I can use target display mode from the iMac? Note the problem isn't with the thunderbolt cable as it works fine on other computers.