On Thu, Nov 23, 2023 at 11:40:25AM +0000, Daniel P. Berrangé 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 > sign-off an thus is misleading/distracting to QEMU contributors. > > 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. > > Signed-off-by: Daniel P. Berrangé <berra...@redhat.com>
Great initiative! I think we needed this for a while now. > --- > 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 The existence? > +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. > + > +Multiple authorship > +~~~~~~~~~~~~~~~~~~~ > + > +It is not uncommon for a patch to have contributions from multiple > +authors. In such a scenario, a git commit will usually be expected > +to have a ``Signed-off-by`` line for each contributor involved in > +creatin of the patch. Some edge cases: creation > + > + * The non-primary author's contributions were so trivial that > + they can be considered not subject to copyright. In this case > + the secondary authors need not include a ``Signed-off-by``. > + > + This case most commonly applies where QEMU reviewers give short > + snippets of code as suggested fixes to a patch. The reviewers > + don't need to have their own ``Signed-off-by`` added unless > + their code suggestion was unusually large. It is still a good policy to include attribution, e.g. by adding a Suggested-by tag. > + > + * Both contributors work for the same employer and the employer > + requires copyright assignment. > + > + It can be said that in this case a ``Signed-off-by`` is indicating > + that the person has permission to contributeo from their employer contribute > + who is the copyright holder. It is none the less still preferrable > + to include a ``Signed-off-by`` for each contributor, as in some > + countries employees are not able to assign copyright to their > + employer, and it also covers any time invested outside working > + hours. > + > +Other commit tags > +~~~~~~~~~~~~~~~~~ > + > +While the ``Signed-off-by`` tag is mandatory, there are a number of > +other tags that are commonly used during QEMU development > + > + * **``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`` > + > + * **``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. > + > + * **``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. Suggested-by is also common. As long as we are here, let's document Fixes: and Cc: ? > +Subsystem maintainer requirements > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +When a subsystem maintainer accepts a patch from a contributor, in > +addition to the normal code review points, they are expected to validate > +the presence of suitable ``Signed-off-by`` tags. > + > +At the time they queue the patch in their subsystem tree, the maintainer > +**MUST** also then add their own ``Signed-off-by`` to indicate that they > +have done the aforementioned validation. Below you say **must** - I think that is better, no need to shout. > + > +The subsystem maintainer submitting a pull request is **NOT** expected to > +have a ``Reviewed-by`` tag on the patch, since this is implied by their > +own ``Signed-off-by``. > + > +Tools for adding ``Signed-of-by`` Signed-off-by > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +There are a variety of ways tools can support adding ``Signed-off-by`` > +tags for patches, avoiding the need for contributors to manually > +type in this repetitive text each time. > + > +git commands > +^^^^^^^^^^^^ > + > +When creating, or amending, a commit the ``-s`` flag to ``git commit`` > +will append a suitable line matching the configuring git author > +details. > + > +If preparing patches using the ``git format-patch`` tool, the ``-s`` > +flag can be used to append a suitable line in the emails it creates, > +without modifying the local commits. Alternatively to modify the > +local commits on a branch en-mass:: > + > + git rebase master -x 'git commit --amend --no-edit -s' > + > +emacs > +^^^^^ > + > +In the file ``$HOME/.emacs.d/abbrev_defs`` add:: > + > + (define-abbrev-table 'global-abbrev-table > + '( > + ("8rev" "Reviewed-by: YOUR NAME <y...@email.addr>" nil 1) > + ("8ack" "Acked-by: YOUR NAME <y...@email.addr>" nil 1) > + ("8test" "Tested-by: YOUR NAME <y...@email.addr>" nil 1) > + ("8sob" "Signed-off-by: YOUR NAME <y...@email.addr>" nil 1) > + )) > + > +with this change, if you type (for example) ``8rev`` followed > +by ``<space>`` or ``<enter>`` it will expand to the whole phrase. > + > +vim > +^^^ > + > +In the file ``$HOME/.vimrc`` add:: > + > + iabbrev 8rev Reviewed-by: YOUR NAME <y...@email.addr> > + iabbrev 8ack Acked-by: YOUR NAME <y...@email.addr> > + iabbrev 8test Tested-by: YOUR NAME <y...@email.addr> > + iabbrev 8sob Signed-off-by: YOUR NAME <y...@email.addr> > + > +with this change, if you type (for example) ``8rev`` followed > +by ``<space>`` or ``<enter>`` it will expand to the whole phrase. > + > +Re-starting abandoned work > +~~~~~~~~~~~~~~~~~~~~~~~~~~ > + > +For a variety of reasons there are some patches that get submitted to > +QEMU but never merged. An unrelated contributor may decide (months or > +years later) to continue working from the abandoned patch and re-submit > +it with extra changes. > + > +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.per...@example.com> > + [Rebased and added support for 'foo'] > + Signed-off-by: New Person <new.per...@example.com> > diff --git a/docs/devel/index-process.rst b/docs/devel/index-process.rst > index 362f97ee30..b54e58105e 100644 > --- a/docs/devel/index-process.rst > +++ b/docs/devel/index-process.rst > @@ -13,6 +13,7 @@ Notes about how to interact with the community and how and > where to submit patch > maintainers > style > submitting-a-patch > + code-provenance > trivial-patches > stable-process > submitting-a-pull-request > diff --git a/docs/devel/submitting-a-patch.rst > b/docs/devel/submitting-a-patch.rst > index c641d948f1..ec541b3d15 100644 > --- a/docs/devel/submitting-a-patch.rst > +++ b/docs/devel/submitting-a-patch.rst > @@ -322,21 +322,9 @@ Patch emails must include a ``Signed-off-by:`` line > > Your patches **must** include a Signed-off-by: line. This is a hard > requirement because it's how you say "I'm legally okay to contribute > -this and happy for it to go into QEMU". The process is modelled after > -the `Linux kernel > -<http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches?id=f6f94e2ab1b33f0082ac22d71f66385a60d8157f#n297>`__ > -policy. > - > -If you wrote the patch, make sure your "From:" and "Signed-off-by:" > -lines use the same spelling. It's okay if you subscribe or contribute to > -the list via more than one address, but using multiple addresses in one > -commit just confuses things. If someone else wrote the patch, git will > -include a "From:" line in the body of the email (different from your > -envelope From:) that will give credit to the correct author; but again, > -that author's Signed-off-by: line is mandatory, with the same spelling. > - > -There are various tooling options for automatically adding these tags > -include using ``git commit -s`` or ``git format-patch -s``. For more > +this and happy for it to go into QEMU". For full guidance, read the > +:ref:`code-provenance` documentation. > + > information see `SubmittingPatches 1.12 > > <http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches?id=f6f94e2ab1b33f0082ac22d71f66385a60d8157f#n297>`__. this "information" now looks orphaned or am I confused? > -- > 2.41.0
