Error message
xillybus: Failed to enable MSI interrupts. Aborting.Meaning
This fatal error message indicates that the driver failed to enable hardware MSI interrupts for the peripheral. This is never expected to happen, unless the kernel was configured at compilation or boot time not to support MSI.
Recommended action
Just to be sure, verify that the kernel supports MSI.
Also, some (old) Linux distributions disable MSI interrupts. You can generally fix this by adding pci=msi to the kernel command line (through your bootloader, e.g. GRUB).
If no apparent reason is found, please report this error. Alternatively, attempt to fix the problem by modifying the kernel module's source code.