[dpdk-stable] [PATCH 20.11 v2 00/18] Backport the new VLAN design for Intel ice PMD

[Wang, Haiyue]

> -----Original Message-----
> From: Kevin Traynor <ktraynor at redhat.com>
> Sent: Thursday, June 17, 2021 18:05
> To: Xueming(Steven) Li <xuemingl at nvidia.com>; Wang, Haiyue <haiyue.wang at intel.com>; Luca Boccassi
> <bluca at debian.org>; stable at dpdk.org
> Cc: NBU-Contact-Thomas Monjalon <thomas at monjalon.net>; christian.ehrhardt at canonical.com; Zhang, Qi Z
> <qi.z.zhang at intel.com>
> Subject: Re: [dpdk-stable] [PATCH 20.11 v2 00/18] Backport the new VLAN design for Intel ice PMD
> 
> On 17/06/2021 09:53, Xueming(Steven) Li wrote:
> > Hi Haiyue,
> >
> >> -----Original Message-----
> >> From: Wang, Haiyue <haiyue.wang at intel.com>
> >> Sent: Thursday, June 17, 2021 9:16 AM
> >> To: Luca Boccassi <bluca at debian.org>; stable at dpdk.org
> >> Cc: Xueming(Steven) Li <xuemingl at nvidia.com>; NBU-Contact-Thomas Monjalon <thomas at monjalon.net>;
> >> christian.ehrhardt at canonical.com; ktraynor at redhat.com; Zhang, Qi Z <qi.z.zhang at intel.com>
> >> Subject: RE: [dpdk-stable] [PATCH 20.11 v2 00/18] Backport the new VLAN design for Intel ice PMD
> >>
> >>> -----Original Message-----
> >>> From: Luca Boccassi <bluca at debian.org>
> >>> Sent: Wednesday, June 16, 2021 23:47
> >>> To: Wang, Haiyue <haiyue.wang at intel.com>; stable at dpdk.org
> >>> Cc: xuemingl at nvidia.com; thomas at monjalon.net;
> >>> christian.ehrhardt at canonical.com; ktraynor at redhat.com; Zhang, Qi Z
> >>> <qi.z.zhang at intel.com>
> >>> Subject: Re: [dpdk-stable] [PATCH 20.11 v2 00/18] Backport the new
> >>> VLAN design for Intel ice PMD
> >>>
> >>> On Fri, 2021-06-11 at 15:15 +0800, Haiyue Wang wrote:
> >>>> When LTS 20.11 was released, the Intel ice PMD has a basic VLAN
> >>>> offload, which can only handle single VLAN mode for firmware
> >>>> limitation. Now the firmware is updated to support double VLAN mode
> >>>> and single VLAN mode at the same time. It depends on the driver to do selection at the boot time.
> >>>>
> >>>> As VLAN protocol handling like strip, filter, flow is very common
> >>>> use, we request to support the ice PMD can run on the latest
> >>>> firmware for enabling the new design. This is compatible backport as the main tree.
> >>>>
> >>>> v2: Fix the subject fix with messy code like : PATCHÂ
> >>>>
> >>>> Haiyue Wang (4):
> >>>>   net/ice/base: do not set VLAN mode in DCF mode
> >>>>   net/ice: fix VLAN strip for double VLAN
> >>>>   net/ice: fix VLAN 0 adding based on VLAN mode
> >>>>   net/ice: update QinQ switch filter handling
> >>>>
> >>>> Junfeng Guo (1):
> >>>>   net/ice: enable QinQ filter for switch
> >>>>
> >>>> Qi Zhang (12):
> >>>>   net/ice/base: align add VSI and update VSI AQ command buffer
> >>>>   net/ice/base: add interface to support configuring VLAN mode
> >>>>   net/ice/base: fix outer VLAN related macro
> >>>>   net/ice/base: add VLAN TPID for VLAN filters
> >>>>   net/ice/base: support checking double VLAN mode
> >>>>   net/ice/base: support configuring device in double VLAN mode
> >>>>   net/ice/base: update boost TCAM for DVM
> >>>>   net/ice/base: change protocol ID for VLAN in DVM
> >>>>   net/ice/base: refactor post DDP download VLAN mode config
> >>>>   net/ice/base: log if DDP/FW do not support QinQ
> >>>>   net/ice/base: add inner VLAN protocol type for QinQ filter
> >>>>   net/ice/base: fix QinQ PPPoE dummy packet selection
> >>>>
> >>>> Yuying Zhang (1):
> >>>>   net/ice/base: add ethertype offset for QinQ dummy packet
> >>>>
> >>>>  drivers/net/ice/base/ice_adminq_cmd.h    | 268 ++++++++-----
> >>>>  drivers/net/ice/base/ice_bitops.h        |  45 +++
> >>>>  drivers/net/ice/base/ice_common.c        |  38 ++
> >>>>  drivers/net/ice/base/ice_common.h        |   4 +
> >>>>  drivers/net/ice/base/ice_flex_pipe.c     | 302 +++++++++++++--
> >>>>  drivers/net/ice/base/ice_flex_pipe.h     |  12 +
> >>>>  drivers/net/ice/base/ice_flex_type.h     |  39 ++
> >>>>  drivers/net/ice/base/ice_protocol_type.h |   1 +
> >>>>  drivers/net/ice/base/ice_switch.c        | 124 +++++-
> >>>>  drivers/net/ice/base/ice_switch.h        |  15 +
> >>>>  drivers/net/ice/base/ice_type.h          |   4 +
> >>>>  drivers/net/ice/base/ice_vlan_mode.c     | 451 ++++++++++++++++++++++
> >>>>  drivers/net/ice/base/ice_vlan_mode.h     |  16 +
> >>>>  drivers/net/ice/base/meson.build         |   1 +
> >>>>  drivers/net/ice/ice_ethdev.c             | 455 +++++++++++++----------
> >>>>  drivers/net/ice/ice_ethdev.h             |  10 +-
> >>>>  drivers/net/ice/ice_generic_flow.c       |   8 +
> >>>>  drivers/net/ice/ice_generic_flow.h       |   1 +
> >>>>  drivers/net/ice/ice_switch_filter.c      | 114 +++++-
> >>>>  19 files changed, 1545 insertions(+), 363 deletions(-)  create mode
> >>>> 100644 drivers/net/ice/base/ice_vlan_mode.c
> >>>>  create mode 100644 drivers/net/ice/base/ice_vlan_mode.h
> >>>
> >>> Hi,
> >>>
> >>> At 1.9k diffstat, this series is quite large. Given it's a new
> >>> feature, rather than a series of bug fixes, this would seem a bit risky to me.
> >>> Final word of course belongs to Xueming, since he's managing this one.
> >>> See:
> >>>
> >>
> 
> Thanks for using the questions as a way to discuss it, it is a good way
> to see if they are useful. Just to note, they were to try and capture
> some of the important things for a maintainer to consider, it is not a
> flow chart leading to a binary answer (though clearly some things like
> ABI breakage, probably would end the discussion).
> 
> >> 01. Does the feature break API/ABI?
> >>
> >>  NO.
> >>
> >> 02. Does the feature break backwards compatibility?
> >>
> >>  NO.
> >>
> >> 03. Is it for the latest LTS release (to avoid LTS upgrade issues)?
> >>
> >> Yes.
> >>
> >> 04. Is there a commitment from the proposer or affiliation to validate the feature and check for
> regressions in related functionality?
> >>
> >> Passed internally, if needed, an official Test-by can be provided.
> >>
> 
> It would be better to share test cases (even high level), not just a
> tested-by which doesn't give any idea of test coverage.

+ Fu Qi, who can share the test cases from dts.

> 
> I would look at it like:
> The new functionality not working with the new firmware and new code is
> not a big issue.
> 
> The old functionality not working with the new firmware and the new code
> is a big issue.
> 
> The old functionality not working with the old firmware and the new code
> is a very big issue.
> 
> So regression testing of the old functionality would be the most
> important IMHO.

This is some kind of compatibility matrix, sure, it make both works. This part
can be covered by the test cases.

> 
> >> 05. Is there a track record of the proposer or affiliation validating stable releases?
> >>
> 
> Yes, Intel tests every LTS release.
> 
> >> Bugzilla ?
> >>
> >> 06. Is it obvious that the feature will not impact existing functionality?
> >>
> >> Yes.
> >>
> 
> No. It is 1.9KLOC change. The key part of the question is "obvious". It
> was meant so the maintainer could use their judgement and review that
> for example, a few lines of code adding a PCI ID or adding a case in a
> switch statement, is obviously not going to impact existing functionality.
> On the other hand, for a more complex code change to existing code, it
> is not immediately obvious that there would be no risk to existing
> functionality.
> 
> >> 07. How intrusive is the code change?
> >>
> >>  From LOC, yes, 1.9K seems to be BIG, but DPDK PMD related is 588, other is  the share code in base
> (1320), which is tested and
> >> validated on other platform.
> >>
> 
> Very intrusive. It seems to be big, because it is big.
> 
> >>      drivers/net/ice/ice_ethdev.c             | 455 +++++++++++++----------
> >>      drivers/net/ice/ice_ethdev.h             |  10 +-
> >>      drivers/net/ice/ice_generic_flow.c       |   8 +
> >>      drivers/net/ice/ice_generic_flow.h       |   1 +
> >>      drivers/net/ice/ice_switch_filter.c      | 114 +++++-
> >>
> >> 08. What is the scope of the code change?
> >>
> >> PMD only.
> >>
> >> 09. Does it impact common components or vendor specific?
> >>
> >> NO.
> >>
> >> 10. Is there a justifiable use case (a clear user need)?
> >>
> >> Yes, for firmware updated. And we have the customer who wants to use the VLAN feature on LTS 20.11.
> >>
> 
> Well, like a lot of the considerations, this is subjective and everyone
> will think there is a need for their own patches, that is a given. It is
> for the maintainer to try and balance the need of the feature against
> the possible impacts to the LTS.
> 
> It seems like you mentioned "for updated firmware" and "customer who
> wants to used the VLAN feature" as separate points. If there is a
> separate need for updating firmware aside from new VLAN functionality,
> it is good to state that.
> 
> >> 11. Is there a community consensus about the backport?
> >>
> >> ...
> >
> > Kevin happens to updated the documents on new feature backport 4 months ago, thanks for checking
> them
> > one by one. Luca's only concern is size of the series, driver vendor is on it's own risk to backport
> a big patch set.
> > The series supports new fw and QinQ, is it easy to split?
> >
> > Kevin, is this the first case of feature backport? How do you think?
> >
> 
> Like Luca, main concern would be the size and intrusiveness of the
> changes, and if it's ok to change 1.9KLOC in this driver now, then why
> not 20KLOC in next release to multiple drivers. I had pushed against a

TBH, we won't want to change the stable i40e, ixgbe PMDs, but ice is a fresh
one, current VLAN has a limited usage, customer is hard to use. That's why we
try to request to backport the new VLAN design.

> LOC limit when this was last discussed at the TB, as it's a crude way to
> judge code complexity/risk, but maybe it should be considered.
> 
> On the positive side it is self-contained and Intel has an excellent
> track record for testing LTS.
> 
> >>
> >>> https://doc.dpdk.org/guides/contributing/stable.html#what-changes-shou
> >>> ld-be-backported
> >>>
> >>> --
> >>> Kind regards,
> >>> Luca Boccassi