Re: [PATCH v6 net-next 00/12] allow user to offload tc action to net device

On Thu 09 Dec 2021 at 11:27, Simon Horman [off-list ref] wrote:

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 200 || true

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

 # tc actions add action police rate 100mbit burst 10000k index 200 skip_sw
 # tc -s -d actions list action police
 total acts 1

         action order 0:  police 0xc8 rate 100Mbit burst 10000Kb mtu 2Kb action reclassify 
         overhead 0b linklayer ethernet
         ref 1 bind 0  installed 142 sec used 0 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
         skip_sw in_hw in_hw_count 1
         used_hw_stats delayed

 # tc filter add dev $DEV protocol ip parent ffff: \
         flower skip_sw ip_proto tcp action police index 200
 # tc -s -d filter show dev $DEV protocol ip parent ffff:
 filter pref 49152 flower chain 0
 filter pref 49152 flower chain 0 handle 0x1
   eth_type ipv4
   ip_proto tcp
   skip_sw
   in_hw in_hw_count 1
         action order 1:  police 0xc8 rate 100Mbit burst 10000Kb mtu 2Kb action 
         reclassify overhead 0b linklayer ethernet
         ref 2 bind 1  installed 300 sec used 0 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
         skip_sw in_hw in_hw_count 1
         used_hw_stats delayed

 # tc filter add dev $DEV protocol ipv6 parent ffff: \
         flower skip_sw ip_proto tcp action police index 200
 # tc -s -d filter show dev $DEV protocol ipv6 parent ffff:
   filter pref 49151 flower chain 0
   filter pref 49151 flower chain 0 handle 0x1
   eth_type ipv6
   ip_proto tcp
   skip_sw
   in_hw in_hw_count 1
         action order 1:  police 0xc8 rate 100Mbit burst 10000Kb mtu 2Kb action 
         reclassify overhead 0b linklayer ethernet
         ref 3 bind 2  installed 761 sec used 0 sec
         Action statistics:
         Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
         backlog 0b 0p requeues 0
         skip_sw in_hw in_hw_count 1
         used_hw_stats delayed

 # tc -s -d actions list action police
 total acts 1

          action order 0:  police 0xc8 rate 100Mbit burst 10000Kb mtu 2Kb action reclassify overhead 0b linklayer ethernet
          ref 3 bind 2  installed 917 sec used 0 sec
          Action statistics:
          Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
          backlog 0b 0p requeues 0
          skip_sw in_hw in_hw_count 1
         used_hw_stats delayed

Changes compared to v5 patches:
* Fix issue reported by Dan Carpenter found using Smatch.

Hi,

Sorry for late response to this and previous version. From my side
series LGTM besides points raised by Jamal and Roi.

Regards,
Vlad

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