On Thu, 19-07-04, 11:52, Adrien Mazarguil wrote: > On Thu, Jul 04, 2019 at 05:52:43AM +0000, Jack Min wrote: > > On Wed, 19-07-03, 17:25, Adrien Mazarguil wrote: > > > On Tue, Jul 02, 2019 at 05:45:55PM +0800, Xiaoyu Min wrote: > > > > support matching on GRE key and present bits (C,K,S) > > > > > > > > example testpmd command could be: > > > > testpmd>flow create 0 ingress group 1 pattern eth / ipv4 / > > > > gre crksv is 0x2000 crksv mask 0xb000 / > > > > gre_key key is 0x12345678 / end > > > > actions rss queues 1 0 end / mark id 196 / end > > > > > > > > Which will match GRE packet with k present bit set and key value is > > > > 0x12345678. > > > > > > > > Signed-off-by: Xiaoyu Min <jack...@mellanox.com> > > > > > > I'm wondering... Is matching the K bit mandatory if one explicitly matches > > > gre_key already or is this a specific hardware limitation in your case? > > > > > > > If there is gre_key item MLX5 PMD will force set HW matching on K bit, > > From HW perspective it is mandatory. But, from testpmd (user) > > perspective, I agree with you, user needn't set matching on K bit if > > they already explicitly set gre_key item. > > OK, makes sense. > > > > Perhaps we could document that the K bit is implicitly matched as "1" in > > > the > > > default mask when a gre_key pattern item is present. If a user explicitly > > > > Yes, I should document this. > > So it should be documented in __testpmd_funcs.rst__ ? > > No it would be a change in the GRE_KEY item itself at the rte_flow API > level (rte_flow.h) & documentation (rte_flow.rst). The flow rules created by > testpmd must be an exact translation of user input, as a debugging tool it > can't request something that wasn't explicitly written. >
will update rte_flow.h & rte_flow.rst > > > spec/mask K as "0" and still provides gre_key, the PMD can safely ignore > > > the > > > gre_key item. > > > > > > > Well, actullay, when a user explicitly set spec/mask K as "0" and still > > provide gre_key item, MLX5 PMD will implicitly set match on K bit as > > "1", just ingore the K bit set by user. > > Not good then. You should spit an error out if it's an impossible > combination. You can't match both K == 0 *and* a GRE key, unless perhaps if > key mask is also 0, e.g.: > > gre crksv is 0x0000 crksv mask 0xb000 / > gre_key value spec 0x00000000 value mask 0x00000000 > Never thought man will wirte thing like this, they don't wanna match gre_key why put the item there ? But, since you have raised this example, I'll update PMD part to handle this. > This is merely an overly complex way for telling the PMD that one wants to > match packets without GRE keys that you could technically support. > > > The reason is wanna keep code simple, needn't to get > > information from other item (gre) inside gre_key item, or vice verse. > > PMDs typically maintain context as they process the pattern. The GRE pattern > item is guaranteed to come before GRE_KEY, so you already know at this point > whether users want to match K at all, and if so, what value they want it to > have. > Yes, PMD can know. Just need to add some code. > > And, I think, when a user provides a gre_key item, most probably, they do > > really wanna match on gre_key. What do you think? > > Depends. They may want to match all GRE traffic with a key, doesn't matter > which, in order to process it through a different path. To do so they could > either: > > 1. Use the GRE item only to match K bit == 1. > > 2. Use the GRE_KEY item to match a nonspecific key value (mask == 0). > > 3. Use a combination of both. > > I think you can easily support all three of them with mlx5 if you support > partial masks on GRE keys (I haven't checked), even if you're unable to > specifically match the K bit itself. > Already support this. > [...] > > > > @@ -755,6 +759,13 @@ static const enum index item_mpls[] = { > > > > > > > > static const enum index item_gre[] = { > > > > ITEM_GRE_PROTO, > > > > + ITEM_GRE_CRKSV, > > > > > > CRKSV may be unnecessary in this patch if the K bit is documented and > > > implemented as described in my previous comment. > > > > > > > Well, actully, we also wanna testpmd can match on C,S bits with K bit > > together so we can test on gre packet with key only or csum + key, or > > csum + key + sequence. > > OK no problem. Perhaps you could make this easier by allowing users to match > individual bits, let me explain: > > The flow command in testpmd is a direct interface to manipulate rte_flow's > structures. The "crksv" field doesn't exist in rte_flow_item_gre, its name > is "c_rsvd0_ver". Testpmd must use the same in its command and internal > code. > > However since bit-masks are usually a pain to mentally work out, you can > provide extras for convenience. The "types" field of the RSS action > (ACTION_RSS_TYPES) is an extreme example of this approach. > > So I suggest adding ITEM_GRE_C_RSVD0_VER taking a 16-bit value like CRKSV, > and complete it with ITEM_GRE_C_BIT, ITEM_GRE_S_BIT and ITEM_GRE_K_BIT > addressing the individual bits you would like to expose for convenience. > So something like: eth / ipv4 / gre c_rsvd0_ver c_bit is 0 s_bit is 0 k_bit is 1 / ... Is it right? > [...] > > > You should have named this field "value" then, i.e.: > > > > > > - ``value {unsigned}``: key value. > > > > > > > OK, I'll update it. > > Please remember to update it in rte_flow.h and documentation as well, > thanks. > OK. > -- > Adrien Mazarguil > 6WIND