Comment 1 for bug 1500175

The "unable to init msix vectors" message is just a warning, and is harmless -- it is expected for the ARM boards. (There's a patch around that suppresses the incorrect warning but unfortunately it didn't get into 2.4.)

Your actual problem is that you haven't specified either a guest kernel (via -kernel) or a firmware image (via a suitable flash drive command). This means that QEMU executes zeroes (which are nop instructions) from its start at address 0 all the way to the end of RAM and then stops because we can't execute out of device registers. (This is approximately what real hardware would do if you booted it with an uninitialized ROM.)

I suggest you provide QEMU with a suitable kernel that will work on a versatile PB board.