On 7/13/20 6:04 PM, Cong Wang wrote:
On Sat, Jul 11, 2020 at 2:28 PM Ariel Levkovich <lar...@mellanox.com> wrote:
Allow user to set a packet's hash value using a bpf program.
The user provided BPF program is required to compute and return
a hash value for the packet which is then stored in skb->hash.
Can be done by act_bpf, right?
Right. We already agreed on that.
Nevertheless, as I mentioned, act_bpf is not offloadable.
Device driver has no clue what the program does.
Using this action to set the skb->hash is an alternative to setting
it with act_skbedit and can be useful for future HW offload support
when the HW hash function is different then the kernel's hash
function.
By using a bpg program that emulates the HW hash function user
can ensure hash consistency between the SW and the HW.
It sounds weird that the sole reason to add a new action is
because of HW offloading. What prevents us extending the
existing actions to support HW offloading?
Thanks.
Something like adding a parameter to act_bpf that provides information
on the program
and what it does?
Ariel
