Hi Andrew,

-----Original Message-----
From: Andrew Rybchenko <redacted>

Hi Ori,

Cc Eli and Ilya since I think OvS could be interested in the feature.

On 6/3/21 11:25 AM, Ori Kam wrote:

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Hi Andrew,

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-----Original Message-----
From: Andrew Rybchenko <redacted>

Hi Ori,

On 6/2/21 4:32 PM, Ori Kam wrote:

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Hi Ivan,

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-----Original Message-----
From: Ivan Malov <redacted>

Hi Ori,

Your review efforts are much appreciated. I understand your concern
about the partial item/action coverage, but there are some points
to be considered when addressing it:
- It's anyway hardly possible to use the printed flow directly in
testpmd if it contains "opaque", or "PMD-specific", items/actions
in terms of the tunnel offload model. These items/actions have to
be omitted when printing the flow, and their absence in the
resulting string means that copy/pasting the flow to testpmd isn't
helpful in this particular case.

I fully agree with you that some of the rules can't be printed. That is why.
I'm not sure having partial solution is the way to go.

Sorry, I disagree that possibility to cover 99% and impossibility to
cover just 1% is the reason to discard.

I agree with you that 99% is better than 0 😊 but is this patch 99%?
maybe we can agree even if it is 70% it is good for this patch.

Hold on. Here we're talking about a theoretical possibility to cover 99%.
Coverage in this patch is discussed below in terms of "the most basic
commands".

I  know that that is why I said 70%.

.

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If OVS for example cares about
some of the item/action, maybe this log should be on their part.

OvS does and as far as I can see already has bugs there.
Of course, nobody says that it is testpmd-complient format, but it
definitely looks so.

Anyway, it sounds strange do duplicate the functionality in many-many
DPDK apps. Of course, it removes the headache from DPDK maintainers,
but it is hardly friendly to DPDK community in general.

Fully agree with you that if some feature is used by number of
applications, then it is better or at least nicer to have it in DPDK,
but my question is that, the current patch is for the OVS use case
from my understanding and not considering any other application. So, in this

case do we want it in DPDK?

The primary goal, in fact, is our testing harness :) OvS is just an open source
example. We could easily add it to our code but decided that it would be useful
in DPDK since seen such messages in OvS logs.

Private application are also good examples from my point of view. 

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- There's action ENCAP which also can't be fully represented by the
tool in question, simply because it has no parameters. In tespmd,
one first has to issue "set vxlan" command to configure the encap.
header, whilst "vxlan" token in the flow rule string just refers to
the previously set encap. parameters. The suggested flow print
helper can't reliably print these two components ("set vxlan" and
the flow rule itself) as they belong to different testpmd command strings.

Again, I agree with you but like my above answer, do we want a
partial solution in DPDK?

My answer is YES.

I can live with such decision but like I said above it depends on the
use case and how partial it is.

See above.

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As you might see, completeness of the solution wouldn't necessarily
be reachable, even if full item/action coverage was provided.

As for the item/action coverage itself, it's rather controversial.
On the one hand, yes, we should probably try to cover more items
and actions in the suggested patch, to the extent allowed by our
current priorities. But on the other hand, the existing coverage
might not be that poor: it's fairly elaborate and at least allows
to print the most common flow rules.

That is my main issue you are going to push something that is good
for you and maybe some other cases, but it can't be used by all
application, even with the most basic commands like encap.

Isn't it fair: if one wants to use something, be ready to help and
extend it. No pain, no gain :) Jokes aside - we're ready to support
"the most basic commands", just list it, but do not say everything is
basic. "everything" will delay the feature and simply unfair to demand

(IMHO).

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IMHO, the feature would make flow API more friendly and easier to
debug, report bugs etc.

I fully agree that if someone wants functionality, he should work for it.
But as a developer of rte_flow and maintainer I need to ask who will
add the new features/missing features? Should we enforce that each
developer when coding a new item/action will add it to the print?
Or just users that care about such log will add it?

It is a good and valid questions. First of all we can help with (or just completely
take it) to maintain the file.

The issue is not the maintaining of the file is the extra work required for each new feature.
and what do we do with features that are hard to print for example encap data?

Second basically any option from above is OK for me.
My personal preference would be to require implementation for new RTE flow
features. In fact, testpmd may start to use it to list created rules etc.
We'll try to make it easier to add new items and actions support.

I also think that the best is that all new features will be added to this print
but the requirement is that adding new this code will not have high overhead.
If we can find and easy way to do it, I think this will be perfect.

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To summarize.
I think the following question must be answer before deciding:
1. how many apps are going to use this feature?

I'll keep OvS maintainers to answer if OvS would like to use it. We'll definitely
use it (either from DPDK or from internal code base if it is not accepted), but I
guess not open source projects may be not taken into account.

Agree lets see the application programmers view point on this.

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2. it the coverage sufficient?

I hope yes, since it tries to warn about not supported features. I.e. it does not lie
simply skipping not supported bits.

But then you can't copy paste it to testpmd and test, which I think is a very good
why to debug issues that costumers may find.

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3. who is responsible to update it? (each developer/the interested
party member?)

See above.

I hope to see more answers here.

+1

Best,
Ori

We'll update it when we need more items/actions to dump.

Thanks,
Andrew.

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Best,
Ori

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Yes, macros and some other cunning ways to cover more flow
specifics might come in handy, but, at the same time, can be rather error

prone.

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Sometimes it's more robust to just write the code out in full.

I'm always in favor of easy of extra complex but too hard is also not good.

Thanks,
Ori

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Thank you.

On 30/05/2021 10:27, Ori Kam wrote:

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Hi Ivan,

First nice idea and thanks for the picking up the ball.

Before a detail review,
The main thing I'm concerned about is that this print will be
partially

supported,

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I know that you covered this issue by printing unknown for
unsupported

item/actions,

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but this will mean that it is enough that one item/action is not
supported

and already the

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flow can't be used in testpmd.
To get full support it means that the developer needs to add such
print

with each new

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item/action. I agree it is possible, but it has high overhead for
each

feature.

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Maybe we should somehow create a macros for the prints or other
easier

to support ways.

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For example, just printing the ipv4 has 7 function calls inside of
it each one

with error checking,

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and I'm not counting the dedicated functions.



Best,
Ori

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-----Original Message-----
From: Ivan Malov <redacted>
Sent: Thursday, May 27, 2021 11:25 AM
To: dev@dpdk.org
Cc: NBU-Contact-Thomas Monjalon <redacted>; Ferruh

Yigit

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[off-list ref]; Andrew Rybchenko
[off-list ref]; Ori Kam [off-list ref]; Ray
Kinsella [off-list ref]; Neil Horman [off-list ref]
Subject: [RFC PATCH] ethdev: add support for testpmd-compliant
flow

rule

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dumping

DPDK applications (for example, OvS) or tests which use RTE flow
API

need to

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log created or rejected flow rules to help to recognise what goes
right or wrong. From this standpoint, testpmd-compliant format is
nice for the purpose because it allows to copy-paste the flow
rules and debug using testpmd.

Recognisable pattern items:
VOID, VF, PF, PHY_PORT, PORT_ID, ETH, VLAN, IPV4, IPV6, UDP, TCP,

VXLAN,

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NVGRE, GENEVE, MARK, PPPOES, PPPOED.

Recognisable actions:
VOID, JUMP, MARK, FLAG, QUEUE, DROP, COUNT, RSS, PF, VF,

PHY_PORT,

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PORT_ID, OF_POP_VLAN, OF_PUSH_VLAN, OF_SET_VLAN_VID,
OF_SET_VLAN_PCP, VXLAN_ENCAP, VXLAN_DECAP.

Recognisable RSS types (action RSS):
IPV4, FRAG_IPV4, NONFRAG_IPV4_TCP, NONFRAG_IPV4_UDP,
NONFRAG_IPV4_OTHER, IPV6, FRAG_IPV6, NONFRAG_IPV6_TCP,
NONFRAG_IPV6_UDP, NONFRAG_IPV6_OTHER, IPV6_EX,

IPV6_TCP_EX,

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IPV6_UDP_EX, L3_SRC_ONLY, L3_DST_ONLY, L4_SRC_ONLY,

L4_DST_ONLY.

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Unrecognised parts of the flow specification are represented by
tokens "{unknown}" and "{unknown bits}". Interested parties are
welcome to extend this tool to recognise more items and actions.

Signed-off-by: Ivan Malov <redacted>