On Tue, Mar 29, 2022 at 2:20 PM Numan Siddique <[email protected]> wrote:
>
> On Mon, Mar 28, 2022 at 1:40 AM Han Zhou <[email protected]> wrote:
> >
> > Some NICs support HW offloading for datapath flows, but masked access to
> > the 128-bit ct_label field may prevent a flow being offloaded due to HW
> > limitations. OVN's use of ct_label currently includes:
> > - ct_label.blocked (1 bit)
> > - ct_label.natted (1 bit)
> > - ct_label.ecmp_reply_port (16 bits)
> > - ct_label.ecmp_reply_eth (48 bits)
> > - ct_label.label (32 bits)
> >
> > This patch moves the bits blocked, natted and ecmp_reply_port to use
> > ct_mark (18 bits in total among the 32-bit ct_mark), and keep the rest
> > of the fields in ct_label:
> > - ct_mark.blocked (1 bit)
> > - ct_mark.natted (1 bit)
> > - ct_mark.ecmp_reply_port (16 bits)
> > - ct_label.ecmp_reply_eth (48 bits)
> > - ct_label.label (32 bits)
> >
> > This would allow HW offloading to work for most of the cases.
> >
> > For ct_label.ecmp_reply_eth, the flow matching it still uses masked
> > access, but it doesn't matter because the flow is for new connections
> > and requires ct_commit in its actions, so it wouldn't be offloaded
> > anyway for those NICs. There is a flow for established connections that
> > would access the masked field in the actions, while in this patch it
> > avoids masked access by using a register xxreg1 to temporarily read the
> > whole ct_label, and then use masked access to xxreg1 to read the actual
> > value.
> >
> > The only exception is for ct_label.label, there is a flow that matches
> > the masked field for ACL logging of reply direction. This patch cannot
> > avoid the masked access to ct_label in this case. This flow is enabled
> > only for the feature "log-related". So offloading may still not work for
> > some NICs when an ACL is configured with a label and with "log-related"
> > enabled.
> >
> > There are no other flows relying on masked ct_label match, but it's
> > worth noting that the LB hairpin related flows using ct_label.natted
> > which were hardcoded directly in ovn-controller are still kept to avoid
> > traffic breaking during upgrading. It relies on the
> > northd-internal-version to internally determine if it is currently
> > upgrading from a version that requires the ct_label flows being
> > kept, and automatically removes the flows when northd-internal-version
> > is up-to-date.
> >
> > Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1957786
>
>
> Thanks for the patch series.
>
> For the entire series:
>
> Acked-by: Numan Siddique <[email protected]>
>
> Numan
>
Thanks Numan! I applied the series to main.

Han

> >
> > v1 -> v2: Fixed two system test cases.
> > v2 -> v3:
> >     - Addressed Numan's comment regarding hairpin flow upgrading
problem by
> >       keeping ct_label flows together with ct_mark flows for hairpin,
and
> >       provided an option to disable ct_label after upgrading.
> >     - Moved a misplaced chunk from patch2 to patch5 to fix related
system tests.
> > v3 -> v4:
> >     - Avoid the extra option to disable ct_label after upgrading for
hairpin
> >       flows. Instead, reuse the north-internal-ver to determine
automatically.
> >       For this to work, a new patch is added to handle SB_Global
changes in I-P
> >       engine of ovn-controller.
> >
> > Han Zhou (6):
> >   ovn-sb.xml: Fix ct_lb documentation.
> >   actions: Add action ct_lb_mark.
> >   actions: Add stack push and pop actions.
> >   ovn-northd: Improve the doc and tests for ecmp-symmetric-reply.
> >   ovn-controller: Handle SB_Global:options:northd_internal_version in
> >     I-P engine.
> >   Use ct_mark for masked access to make flows HW-offloading friendly.
> >
> >  NEWS                         |   2 +
> >  controller/lflow.c           |  33 ++-
> >  controller/lflow.h           |   1 +
> >  controller/ovn-controller.c  |  79 ++++++
> >  include/ovn/actions.h        |  11 +-
> >  include/ovn/logical-fields.h |   3 +
> >  lib/actions.c                | 128 ++++++++-
> >  lib/logical-fields.c         |  17 +-
> >  lib/ovn-util.c               |  25 +-
> >  lib/ovn-util.h               |   4 +
> >  northd/northd.c              | 107 ++++---
> >  northd/ovn-northd.8.xml      |  59 ++--
> >  ovn-sb.xml                   |  54 +++-
> >  tests/ovn-controller.at      |  46 +++
> >  tests/ovn-northd.at          | 526 ++++++++++++++++++-----------------
> >  tests/ovn.at                 | 208 +++++++-------
> >  tests/system-ovn.at          | 178 ++++++------
> >  utilities/ovn-trace.c        |  72 ++++-
> >  18 files changed, 1017 insertions(+), 536 deletions(-)
> >
> > --
> > 2.30.2
> >
> > _______________________________________________
> > dev mailing list
> > [email protected]
> > https://mail.openvswitch.org/mailman/listinfo/ovs-dev
> >
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