Hi,
On 03/02/2022 12:54, Juergen Gross wrote:
+## The commit message
+
+The commit message is free text describing *why* the patch is done and
+*how* the goal of the patch is achieved. A good commit message will describe
+the current situation, the desired goal, and the way this goal is being
+achieved. Parts of that can be omitted in obvious cases.
+
+In case additional changes are done in the patch (like e.g. cleanups), those
+should be mentioned.
+
+When referencing other patches (e.g. `similar to patch xy ...`) those
+patches should be referenced via their commit id (at least 12 digits)
+and the patch subject, if the very same patch isn't referenced by the
+`Fixes:` tag, too:
+
+ Similar to commit 67d01cdb5518 ("x86: infrastructure to allow converting
+ certain indirect calls to direct ones") add ...
+
+The following ``git config`` settings can be used to add a pretty format for
+outputting the above style in the ``git log`` or ``git show`` commands:
+
+ [core]
+ abbrev = 12
+ [pretty]
+ fixes = Fixes: %h (\"%s\")
+
+Lines in the commit message should not exceed 75 characters, except when
I was under the impression that commit message should be wrap to 72
characters. This is because tools like "git log" would indent the commit
message by 8 characters.
+copying error output directly into the commit message.
+
+## Tags
+
+Tags are entries in the form
+
+ Tag: something
+
+In general tags are added in chronological order. So a `Reviewed-by:` tag
+should be added **after** the `Signed-off-by:` tag, as the review happened
+after the patch was written.
+
+Do not split a tag across multiple lines, tags are exempt from the
+"wrap at 75 columns" rule in order to simplify parsing scripts.
This would need to be adjusted depending on the answer above.
+
+### Origin:
+
+Xen has inherited some source files from other open source projects. In case
+a patch modifying such an inherited file is taken from that project (maybe in
+modified form), the `Origin:` tag specifies the source of the patch:
+
+ Origin: <repository-URL> <commit-id>
NIT: Likes you did for Fixes tags, can you make clear that the commit id
should be the first 12 characters? So the line...
+
+E.g.:
+
+ Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
f093b08c47b3
... doesn't get horribly long.
+
+All tags **above** the `Origin:` tag are from the original patch (which
+should all be kept), while tags **after** `Origin:` are related to the
+normal Xen patch process as described here.
Cheers,
--
Julien Grall
