[dpdk-dev] [PATCH v6 07/16] ethdev: flatten RSS configuration in flow API

[Adrien Mazarguil]

Hi Peng Yuan,

Apologies for the delay, I'll answer below to the entire thread.

On Sat, Apr 28, 2018 at 07:45:31AM +0000, Peng, Yuan wrote:
> Hi，Adrien Mazarguil
> 
> There is a bug of queue region with 18.05-rc1
> The test steps are as below:
> ./usertools/dpdk-devbind.py -b igb_uio 05:00.0
> ./x86_64-native-linuxapp-gcc/app/testpmd -c 1ffff -n 4 -- -i --rxq=16 --txq=16
> testpmd> port config all rss all
> Configuration of RSS hash at ethernet port 0 failed with error (22): Invalid argument.

I assume this issue is related rte_eth_dev_configure() which was recently
fixed [1], right?

[1] "ethdev: fix applications failure on configure"
    http://dpdk.org/ml/archives/dev/2018-May/099858.html

<snip>
> There is a bug present with 18.05-rci when I test the feature "Move RSS to rte_flow" in i40e NIC
> The test steps are as below:
> ./usertools/dpdk-devbind.py -b igb_uio 05:00.0 05:00.1
> ./x86_64-native-linuxapp-gcc/app/testpmd -c 0x1fffe -n 4  -- -i --nb-cores=8 --rxq=8 --txq=8 --port-topology=chained
> testpmd> set fwd rxonly
> Set rxonly packet forwarding mode
> testpmd> set verbose 1
> Change verbose level from 0 to 1
> testpmd> start
> testpmd> flow create 0 ingress pattern end actions rss queues 0 4 7 end / end
> Caught error type 16 (specific action): cause: 0x7fff84e33658, RSS hash key too large
> 
> The rss rule can be set successfully when I test it yesterday with older dpdk version without this patch.

Regarding this issue, the testpmd flow command now requests hash key length
from the PMD by default [2] if left unspecified by user. This value is taken
from the "hash_key_size" field returned by rte_eth_dev_infos_get().

While most PMDs return 40 here, i40e returns:

 (I40E_PFQF_HKEY_MAX_INDEX + 1) * sizeof(uint32_t)
 /* that is, (12 + 1) * 4 => 52 */

Is this correct and really supported by i40e? Otherwise I'd suggest to fix
the PMD as it may also confuse applications other than testpmd.

Note that you should be able to revert to the old behavior with the
PMD-specific default key by specifying a "key_len 0" parameter to the RSS
action.

[2] http://dpdk.org/browse/dpdk/tree/app/test-pmd/cmdline_flow.c?id=v18.05-rc2#n2780

<snip>
> There is another problem with ixgbe nic:
> ./usertools/dpdk-devbind.py -b igb_uio 07:00.0 07:00.1
> ./x86_64-native-linuxapp-gcc/app/testpmd -c 0x1fffe -n 4  -- -i --nb-cores=8 --rxq=8 --txq=8 --disable-rss --port-topology=chained 
> testpmd> flow create 0 ingress pattern end actions rss queues 5 6 7 end / end
> Caught error type 2 (flow rule (handle)): Failed to create flow.
> The rule setting command can be executed successfully with older dpdk version.
> 
> Could you help to check if there is a relationship between the bugs and this patch?

Perhaps a similar issue since testpmd now provides default values for
unspecified fields of the RSS action, that is, a default hash key with a
PMD-returned default length and the global "rss_hf" value for types (here 0
due to --disable-rss).

Try appending the following arguments to the RSS action:

 key_len 0 types ip udp end

If it works, it probably means the issue was always present, it just never
showed up due to the inability to validate RSS action parameters
previously. You should make sure ixgbe supports them.

-- 
Adrien Mazarguil
6WIND