package rdma-core needed for mlx functionality

[Christian Ehrhardt ]

[Impact]

 * the librte-mlx PMD drivers will need rdma-core to properly work in some
   setups.

 * Solution: add the missing dependency.

[Test Case]

 * Install DPDK 18.11.x in particular librte-pmd-mlx5-18.11 and
   librte-pmd-mlx4-18.11
 * Those should now depend on rdma-core which will make the MLX
   initialization work on the systems where it was failing so far.

 * Further some MLX cards hard-fail initialization without the fix, but we
   have no such card available [1]. But we can try if our cards still
   initialize correctly.

[1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925141#50

[Regression Potential]

 * The one thing we have identified is the obvious extra clutter that will
   be installed. But for users of librte-pmd-mlx[45]-18.11 this really
   will improve reliability and others (that e.g. do not want to use mlx
   PMDs can remove the packages. You can perfectly fine have e.g. PMDs for
   intel cards installed but mlx PMDs removed.
   The default "dpdk" only depends on some core libs and RECOMMENDS the
   common PMDs. Uncommon PMDs are opt-in installs anyway and one can even
   remove common PMDs to e.g. reduce the active code.
   That way people concerned of the extra clutter can avoid it, while real
   users of MLX PMDs will benefit from better device support.

[Other Info]

 * n/a

---

The MLX drivers correctly depend on the symbols they need e.g.:
  ibverbs-providers (>= 15), libc6 (>= 2.14), libibverbs1 (>= 1.1.6)

But with that they load correctly, but do not find the cards.

Most likely because the kernel modules and/or services are not up.
It was reported that rdma-core will fix this.

We don't want to pull in rdma-core on all older updates, but on newer versions we might add a dependency to it.

I'm not entirely sure - on one hand DPDK already pulls in a lot anyway.
But OTOH maybe we make it a suggests?
Yet the rdma-modules will not do a lot when no HW is present and also the services should be somewhat lightweight if there is no HW present.
Finally running DPDK is never lightweight to begin with - so maybe a depends from the MLX PMDs would be the most appropriate?

@Alaaa (if you are reading this) - do you happen to know which bit of rdma-cores functionality exactly it is that makes it work?

[Christian Ehrhardt  (paelzer)]

I'll discuss that with Luca on Thursday, he has MLX in his setups as well.

[Christian Ehrhardt  (paelzer)]

To underline here a message I just got from MLX:
"rdma-core is a must to be able to use MLX PMD's"

That we need it seems clear, the question will be:
- depends, recommends or suggests?
- do we SRU any of that?

[Christian Ehrhardt  (paelzer)]

After discussion with Luca I file a bug for rdma-core and put Luca as well as Thomas Monjalon on CC to get their opinion on all of this.

[Christian Ehrhardt  (paelzer)]

Fixed in Debian but not breaking the freeze in Disco.
This will be synced into 19.10 later on and then considered for an 19.04 SRU.

[Christian Ehrhardt  (paelzer)]

Fixed in Eoan, forgot the bug ref :-/

[Christian Ehrhardt  (paelzer)]

Uploaded to -unapproved as part of the Stable release.
Adding SRU template here.

[Łukasz Zemczak (sil2100)]

An upload of dpdk to disco-proposed has been rejected from the upload queue for the following reason: "Attached bug LP: #1784816 seems to point to a previous (different) stable version update (already released). Could we get a new bug for the new update, with proper release notes linked in?".

[Łukasz Zemczak (sil2100)]

Hello Christian, or anyone else affected,

Accepted dpdk into disco-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/dpdk/18.11.2-1ubuntu0.19.04.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested and change the tag from verification-needed-disco to verification-done-disco. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-disco. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Christian Ehrhardt  (paelzer)]

I checked installs with proposed enabled.
Now rdma-core is correctly pulled in on installs.

Also as planned, if wanted I can uninstall MLX and get rid of it (dpdk->mlx4|5 is only recommends).

$ sudo apt remove librte-pmd-mlx4-18.11 librte-pmd-mlx5-18.11
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following package was automatically installed and is no longer required:
  rdma-core
Use 'sudo apt autoremove' to remove it.
The following packages will be REMOVED:
  librte-pmd-mlx4-18.11 librte-pmd-mlx5-18.11

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for dpdk has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package dpdk - 18.11.2-1ubuntu0.19.04.1

---------------
dpdk (18.11.2-1ubuntu0.19.04.1) disco; urgency=medium

  * Make DPDK LTS release available in Disco (LP: #1836365)
    - includes a fix for mlx rdma-core dependencies (LP: #1820957)

dpdk (18.11.2-1) experimental; urgency=medium

  [ Christian Ehrhardt ]
  * Merge stable update to 18.11.2; For a list of changes see
    http://doc.dpdk.org/guides-18.11/rel_notes/release_18_11.html#id1
    - refresh 0004-build-bump-minimum-Meson-version-to-0.47.1.patch for 18.11.2
    - drop changes upstream in 18.11.2
      0002-build-use-generic-march-on-arm64-when-using-default.patch
      lp-1827102-kni-fix-build-with-Linux-5.1.patch

  [ Santiago Ruano Rincón ]
  * debian/rules: clean doc files

dpdk (18.11.1-3) experimental; urgency=medium

  * d/control: add dependencies to libdpdk-dev: libelf-dev and libjansson-dev
    to avoid pkg-config issues
  * d/control: drop unused build dependency to libcap-dev

dpdk (18.11.1-2) experimental; urgency=medium

  [ Christian Ehrhardt ]
  * d/control: drop shlibs:Depends from dpdk as it has no binaries anymore
  * d/p/lp-1827102-kni-fix-build-with-Linux-5.1.patch fix kni DKMS build with
    Linux 5.1 kernels (LP: #1827102)

  [ Luca Boccassi ]
  * Bump Standards-Version to 4.3.0, no changes.

dpdk (18.11.1-1) experimental; urgency=medium

  [ Christian Ehrhardt ]
  * Merge stable update to 18.11.1; For a list of changes see
    https://doc.dpdk.org/guides-18.11/rel_notes/release_18_11.html
    - refresh 0004-build-bump-minimum-Meson-version-to-0.47.1.patch for 18.11.1
    - drop changes upstream in 18.11.1
      0001-doc-fix-garbage-text-in-generated-HTML-guides.patch
      0003-build-mention-march-in-pkg-config-description.patch
      0001-kni-fix-build-for-dev_open-in-Linux-5.0.patch
      0002-kni-fix-build-for-igb_ndo_bridge_setlink-in-Linux-5..patch
  * d/control: fix usability issue with mlx PMDs which might need rdma-core
    to be installed. In most cases users will want this, to be able to
    drop rdma-core if unwanted in some cases this is only a recommends added
    to librte-pmd-mlx4-18.11 and librte-pmd-mlx5-18.11 (Closes: #925141)

 -- Christian Ehrhardt <email address hidden> Fri, 12 Jul 2019 14:35:59 +0200