What cabling would one need to go from ConnectX-2 VPI to XFP 10Gigabit ethernet (with CX4 XFPs)

I’ve got a couple of ConnectX-2 and ConnectX VPI cards, and the QSFP to CX4 cables I purchased seem to not understand that the other side is 10Gigabit ethernet. What cabling would I need to make those ports understand that they’re connected to a 10GigE switch?

Current: (HCA) QSFP → CX4 (passive) CX4 → XFP (Force10 E600)

I’ve attempted the above with a variety of different card driver settings (on linux) and none of them work (inbox and mlnx_ofed) - ibstatus always reports ‘state: 1: DOWN’ and ‘phys state: 3: Disabled’. I attempted to email support@mellanox, but since I don’t have an active service contract they referred me here.

Does anybody have a working ConnectX-2 VPI to XFP 10GbE setup? If so, what cables/adapters did you use?