/etc/rc.local:

# enable Receive packet steering on eth0
# This works for 'vif' interface on amazon.
# For HVM machines with 'Enhanced networking', grep for eth0-TxRx
# Note that this only works for ixgbevf driver with a single TxRx queue.
# If that command returns 2 values, you'll have to iterate over them and tweak the CPU mask below
ETH0_IRQ=`awk -F: '/eth0/ {print $1}' </proc/interrupts | tr -d ' '`

# interrupts on CPU0 only
echo '00000001' >/proc/irq/$ETH0_IRQ/smp_affinity

# Configure RPS on 7 CPUs in the same NUMA domain as CPU0
echo '000000fe' >/sys/class/net/eth0/queues/rx-0/rps_cpus