Netfilter nf_tables hardware flow offload module

modulename: nft_flow_offload.ko

configname: CONFIG_NFT_FLOW_OFFLOAD

Linux Kernel Configuration
└─>Networking support
└─>Networking options
└─>Network packet filtering framework (Netfilter)
└─>Core Netfilter Configuration
└─>Netfilter nf_tables hardware flow offload module
In linux kernel since version 4.2 (release Date: 2015-08-30)  
This option adds the "flow_offload" expression that you can use to
choose what flows are placed into the hardware.

source code:
net/netfilter/nft_flow_offload.c