PCI Express diagnostics

We are doing PCIe using an Arria II GX45. It works, but we'd like to pull some signals out of the FPGA to flag packet activity and packet errors, so we can see these things on a scope in real time, and maybe drive some counters to get statistics. The PCIe hard core has some outrageous number of test outputs, but they aren't documented.

Any ideas, links, suggestions?

Thanks

John