Re: [PATCH 1/2] docs: introduce dedicated page about code provenance / sign-off

["Daniel P. Berrangé" <berrange@redhat.com>]

On Thu, Nov 23, 2023 at 01:01:00PM +0000, Peter Maydell wrote:
> On Thu, 23 Nov 2023 at 11:40, Daniel P. Berrangé <berrange@redhat.com> wrote:
> >
> > Currently we have a short paragraph saying that patches must include
> > a Signed-off-by line, and merely link to the kernel documentation.
> > The linked kernel docs have alot of content beyond the part about
> 
> "a lot"
> 
> > sign-off an thus is misleading/distracting to QEMU contributors.
> 
> "and thus are"
> 
> >
> > This introduces a dedicated 'code-provenance' page in QEMU talking
> > about why we require sign-off, explaining the other tags we commonly
> > use, and what to do in some edge cases.
> 
> Good idea; I've felt for a while now that it was a little awkward
> to have to point people at that big kernel doc page.
> 
> 
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> > ---
> >  docs/devel/code-provenance.rst    | 197 ++++++++++++++++++++++++++++++
> >  docs/devel/index-process.rst      |   1 +
> >  docs/devel/submitting-a-patch.rst |  18 +--
> >  3 files changed, 201 insertions(+), 15 deletions(-)
> >  create mode 100644 docs/devel/code-provenance.rst
> >
> > diff --git a/docs/devel/code-provenance.rst b/docs/devel/code-provenance.rst
> > new file mode 100644
> > index 0000000000..b4591a2dec
> > --- /dev/null
> > +++ b/docs/devel/code-provenance.rst
> > @@ -0,0 +1,197 @@
> > +.. _code-provenance:
> > +
> > +Code provenance
> > +===============
> > +
> > +Certifying patch submissions
> > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > +
> > +The QEMU community **mandates** all contributors to certify provenance
> > +of patch submissions they make to the project. To put it another way,
> > +contributors must indicate that they are legally permitted to contribute
> > +to the project.
> > +
> > +Certification is achieved with a low overhead by adding a single line
> > +to the bottom of every git commit::
> > +
> > +   Signed-off-by: YOUR NAME <YOUR@EMAIL>
> > +
> > +This existence of this line asserts that the author of the patch is
> > +contributing in accordance with the `Developer's Certificate of
> > +Origin <https://developercertifcate.org>`__:
> > +
> > +.. _dco:
> > +
> > +::
> > +  Developer's Certificate of Origin 1.1
> > +
> > +  By making a contribution to this project, I certify that:
> > +
> > +  (a) The contribution was created in whole or in part by me and I
> > +      have the right to submit it under the open source license
> > +      indicated in the file; or
> > +
> > +  (b) The contribution is based upon previous work that, to the best
> > +      of my knowledge, is covered under an appropriate open source
> > +      license and I have the right under that license to submit that
> > +      work with modifications, whether created in whole or in part
> > +      by me, under the same open source license (unless I am
> > +      permitted to submit under a different license), as indicated
> > +      in the file; or
> > +
> > +  (c) The contribution was provided directly to me by some other
> > +      person who certified (a), (b) or (c) and I have not modified
> > +      it.
> > +
> > +  (d) I understand and agree that this project and the contribution
> > +      are public and that a record of the contribution (including all
> > +      personal information I submit with it, including my sign-off) is
> > +      maintained indefinitely and may be redistributed consistent with
> > +      this project or the open source license(s) involved.
> > +
> > +It is generally expected that the name and email addresses used in one
> > +of the ``Signed-off-by`` lines, matches that of the git commit ``Author``
> > +field. If the person sending the mail is also one of the patch authors,
> > +it is further expected that the mail ``From:`` line name & address match
> > +one of the ``Signed-off-by`` lines.
> 
> Is it? Patches sent via the sr.ht service won't do that, and I'm
> pretty sure we've had a few contributors in the past who send
> patches from different addresses to avoid problems with their
> corporate mail server mangling patches. I think this would be
> better softened to something like a recommendation ("Generally
> you should use the same email addresses ... ").

Yes, I forgot about sr.ht being wierd in this respect, so I'll
take your suggestion.


> > +
> > + * **``Reviewed-by``**: when a QEMU community member reviews a patch
> > +   on the mailing list, if they consider the patch acceptable, they
> > +   should send an email reply containing a ``Reviewed-by`` tag.
> > +
> > +   NB: a subsystem maintainer sending a pull request would replace
> > +   their own ``Reviewed-by`` with another ``Signed-off-by``
> 
> I agree with Philippe here -- you add signed-off-by, you don't
> replace reviewed-by.

Yep, will change that.

> 
> > +
> > + * **``Acked-by``**: when a QEMU subsystem maintainer approves a patch
> > +   that touches their subsystem, but intends to allow a different
> > +   maintainer to queue it and send a pull request, they would send
> > +   a mail containing a ``Acked-by`` tag.
> 
> I would personally also say "Acked-by does not imply a full code
> review of the patch; if the subsystem maintainer has done a full
> review, they should use the Reviewed-by tag instead."
> 
> But I know that there are some differences of opinion on exactly
> what Acked-by: means...

I'll incorporate something along those lines with a little fuzzyness
to give flexibility.

> > +
> > + * **``Tested-by``**: when a QEMU community member has functionally
> > +   tested the behaviour of the patch in some manner, they should
> > +   send an email reply conmtaning a ``Tested-by`` tag.
> > +
> > + * **``Reported-by``**: when a QEMU community member reports a problem
> > +   via the mailing list, or some other informal channel that is not
> > +   the issue tracker, it is good practice to credit them by including
> > +   a ``Reported-by`` tag on any patch fixing the issue. When the
> > +   problem is reported via the GitLab issue tracker, however, it is
> > +   sufficient to just include a link to the issue.
> 
> Maybe we should add a bit of encouraging text here along the lines of:
> 
> Reviewing and testing is something anybody can do -- if you've
> reviewed the code or tested it, feel free to send an email with
> your tag to say you've done that, or to ask questions if there's
> part of the patch you don't understand.
> 
> ? Or perhaps that would be better elsewhere; IDK.

I'll put a little bit in here but want to keep it relatively
concise, since we have other docs about more general contribution
practices.



> > +If the abandoned patch already had a ``Signed-off-by`` from the original
> > +author this **must** be preserved. The new contributor **must** then add
> > +their own ``Signed-off-by`` after the original one if they made any
> > +further changes to it. It is common to include a comment just prior to
> > +the new ``Signed-off-by`` indicating what extra changes were made. For
> > +example::
> > +
> > +  Signed-off-by: Some Person <some.person@example.com>
> > +  [Rebased and added support for 'foo']
> > +  Signed-off-by: New Person <new.person@example.com>
> 
> You might want to use two different email domains in this example;
> an abandoned project picked up by somebody from the same company
> (assuming the usual copyright-belongs-to-company) is a bit different
> from an abandoned project picked up by an entirely unrelated person.

Yes good idea.

> I think in this case it's also worth stating the general principles:
> 
> ===begin===
> The general principles with picking up abandoned work are:
>  * we should continue to credit the first author for their work
>  * we should track the provenance of the code
>  * we should also acknowledge the efforts of the person picking
>    up the work
>  * the commit messages should indicate who is responsible for
>    what parts of the final patch
> 
> In complicated cases or if in doubt, you can always ask on the
> mailing list for advice.
> 
> If the new work you'd need to do to resubmit the patches is
> significant, it's worth dropping the original author a
> friendly email to let them know, in case you might be
> duplicating something the original author is still working on.
> ===endit===
> 
> perhaps ?

I'll incorporate somethnig along these lines.

With regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|