On Thu, Oct 15, 2020 at 4:54 PM Ferruh Yigit <[email protected]> wrote: > > On 10/16/2020 12:21 AM, Ophir Munk wrote: > >> From: Ferruh Yigit <[email protected]> > >>>>> On 10/15/2020 1:41 PM, Lijun Ou wrote: > >>>>>> When start the testpmd, the pmd driver initializes the RSS > >>>>>> configuration. Generally, the recommended RSS hash key is used as > >>>>>> the default key in the driver. In addition, the default key is > >>>>>> different from the default RSS flow in testpmd without specifying > >>>>>> RSS hash key. So. if you do not specify the RSS key when creating > >>>>>> an RSS rule, the testpmd uses the default key as the default RSS > >>>>>> key of the RSS rule. As a result, you may mistakenly consider that > >>>>>> the RSS key in use is the valid default key of the NIC, actually, > >>>>>> the key and the valid default key of the NIC are two values. > >>>>>> > >>>>>> Consider the follow usage with testpmd: > >>>>>> 1. first, startup testpmd: > >>>>>> testpmd> show port 0 rss-hash key > >>>>>> RSS functions: > >>>>>> all ipv4-frag ipv4-other ipv6-frag ipv6-other ip RSS key: > >>>>>> - > >> 6D5A56DA255B0EC24167253D43A38FB0D0CA2BCBAE7B30B477CB2DA3803 > >> 0F > >>>>>> -20C6A42B73BBEAC01FA > >>>>>> 2. create a rss rule > >>>>>> testpmd> flow create 0 ingress pattern eth / ipv4 / udp / end > >>>>>> testpmd> actions rss \ > >>>>>> types ipv4-udp end queues end / end > >>>>>> > >>>>>> 3. show rss-hash key > >>>>>> testpmd> show port 0 rss-hash key > >>>>>> RSS functions: > >>>>>> all ipv4-udp udp > >>>>>> RSS key: > >>>>>> - > >> 74657374706D6427732064656661756C74205253532068617368206B65792C > >> 206F > >>>>>> -76657272696465 > >>>>>> > >>>>>> In order to solve the above problems, it use the NIC valid default > >>>>>> RSS key instead of the testpmd dummy RSS key in the flow > >>>>>> configuration when the RSS key is not specified in the flow rule. > >>>>>> If the NIC RSS key is invalid, it will use testpmd dummy RSS key as the > >> default key. > >>>>>> > >>>>>> Fixes: ac8d22de2394 ("ethdev: flatten RSS configuration in flow > >>>>>> API") > >>>>>> Cc: [email protected] > >>>>>> > >>>>>> Signed-off-by: Lijun Ou <[email protected]> > >>>>>> Reviewed-by: Phil Yang <[email protected]> > >>>>>> --- > >>>>>> V4->V5: > >>>>>> -rewrite the commit log > >>>>>> -add reviewed-by > >>>>> > >>>>> Hi Lijun, > >>>>> > >>>>> There were multiple other comments, it seems they are not addressed > >>>>> but only updated the commit log, can you please check comments to > >> prev versions. > >>>>> > >>>>> Before going into the details, my question was what happens if > >>>>> default key not provided at all? > >>>>> It seems this has been already tried by Ophir [1], later reverted > >>>>> back [2] bringing the initial issue back. > >>>>> > >>>>> According commit, the reason of revert is to support following > >> command: > >>>>> "flow create 0 <pattern> actions rss queues 0 1 end key_len 40 / end" > >>>>> > >>>>> @Ophir, @Lijun, > >>>>> Can we ignore the 'key_len' if the 'key' is not supported and solve > >>>>> current issue as initially intended ([1])? > >>>>> > >>>> Hi, Ferruh > >>>> I have discussed with Phil Yang about the problem in [1]. I think > >>>> there may be other problems with the idea and there is no better > >>>> solution. and we need to remove key_len definition from rte_rss_conf > >>>> structure. They don't have a plan. And [1] was eventually reverted. > >>>> > >>> > >>> Why ignoring 'key_len' (set it to zero) when there is no 'key' > >>> provided doesn't work? > >>> > >> > >> What do you think [1] + following update, will it work? > >> > >> diff --git a/lib/librte_ethdev/rte_flow.c b/lib/librte_ethdev/rte_flow.c > >> index ee4f3464fe..e7789c87b3 100644 > >> --- a/lib/librte_ethdev/rte_flow.c > >> +++ b/lib/librte_ethdev/rte_flow.c > >> @@ -535,7 +535,7 @@ rte_flow_conv_action_conf(void *buf, const size_t > >> size, > >> }), > >> size > sizeof(*dst.rss) ? sizeof(*dst.rss) : > >> size); > >> off = sizeof(*dst.rss); > >> - if (src.rss->key_len) { > >> + if (src.rss->key_len && src.rss->key) { > >> off = RTE_ALIGN_CEIL(off, > >> sizeof(*dst.rss->key)); > >> tmp = sizeof(*src.rss->key) * src.rss->key_len; > >> if (size >= off + tmp) > >> > > > > Ferruh, your suggestion ([1] + update) looks correct. I also verified it on > > mlx5 PMD. > > Advantage: it's a generic fix for all dpdk applications using rte_flows > > (not just testpmd). > > It reduces code. > > With this fix the responsibility of handling key==NULL and/or len==0 is > > moved to the PMDs (which is good). > > > > With regard to Lijun patch - I liked the approach of overriding the default > > testpmd key with the default PMD key. > > But it only addresses testpmd. More code was added. > > It seems OK to call rte_eth_dev_rss_hash_conf_get() as part of parsing RSS, > > but it would feel more confident if we could confirm it for all the PMDs > > (by testing) or at least review the PMDs rss_hash_conf_get() > > implementations. > > > > Lijun's idea can work. There was a problem in implementation related to the > key > size assumption, which can be fixed. > > Even it is fixed, when user gives a rss rule without a key, we are getting key > from device and feeding same key back to device, this is unnecessary I think. > When user didn't provide a key, rss rule shouldn't touch the key at all. +1 But can we add this as expected behavior in the rte_flow document.
> > Complication was when user provides key_len without a key, I think both > ignoring > or returning error in this case is OK. Let's return an error if key_len is provided without a key.
