Re: [RFC/PATCH net-next v3 0/8] allow user to offload tc action to net device

On 2021-10-31 05:50, Oz Shlomo wrote:

On 10/28/2021 2:06 PM, Simon Horman wrote:

quoted

Baowen Zheng says:

Allow use of flow_indr_dev_register/flow_indr_dev_setup_offload to 
offload
tc actions independent of flows.

The motivation for this work is to prepare for using TC police action
instances to provide hardware offload of OVS metering feature - which 
calls
for policers that may be used by multiple flows and whose lifecycle is
independent of any flows that use them.

This patch includes basic changes to offload drivers to return EOPNOTSUPP
if this feature is used - it is not yet supported by any driver.

Tc cli command to offload and quote an action:

tc qdisc del dev $DEV ingress && sleep 1 || true
tc actions delete action police index 99 || true

tc qdisc add dev $DEV ingress
tc qdisc show dev $DEV ingress

tc actions add action police index 99 rate 1mbit burst 100k skip_sw
tc actions list action police

tc filter add dev $DEV protocol ip parent ffff:
flower ip_proto tcp action police index 99
tc -s -d filter show dev $DEV protocol ip parent ffff:
tc filter add dev $DEV protocol ipv6 parent ffff:
flower skip_sw ip_proto tcp action police index 99
tc -s -d filter show dev $DEV protocol ipv6 parent ffff:
tc actions list action police

tc qdisc del dev $DEV ingress && sleep 1
tc actions delete action police index 99
tc actions list action police

Actions are also (implicitly) instantiated when filters are created.
In the following example the mirred action instance (created by the 
first filter) is shared by the second filter:

tc filter add dev $DEV1 proto ip parent ffff: flower \
     ip_proto tcp action mirred egress redirect dev $DEV3

tc filter add dev $DEV2 proto ip parent ffff: flower \
     ip_proto tcp action mirred index 1

I sure hope this is supported. At least the discussions so far
are a nod in that direction...
I know there is hardware that is not capable of achieving this
(little CPE type devices) but lets not make that the common case.

cheers,
jamal