The NUMA node information for PCI devices provided through
sysfs is invalid for AMD Opteron(TM) Processor 62xx and 63xx
on Red Hat Enterprise Linux 6, and VMs on some hypervisors.
It is good to see more checking for valid values.
Typical wrong numa node in some VMs:
$ cat /sys/devices/pci0000:00/0000:00:18.6/numa_node
-1