Daniel P. Berrangé <berra...@redhat.com> writes: > On Wed, Oct 18, 2023 at 06:51:41AM -0400, Michael S. Tsirkin wrote: >> On Wed, Oct 18, 2023 at 12:36:10PM +0200, Markus Armbruster wrote: >> > > x- seems safer for management tool that doesn't know about "unstable" >> > > properties.. >> > >> > Easy, traditional, and unreliable :) >> >> > > But on the other hand, changing from x- to no-prefix is already >> > > done when the feature is stable, and thouse who use it already >> > > use the latest version of interface, so, removing the prefix is >> > > just extra work. >> > >> > Exactly. >> > >> >> I think "x-" is still better for command line use of properties - we >> don't have an API to mark things unstable there, do we? > > Personally I like to see "x-" prefix present *everywhere* there is > an unstable feature, and consider the need to rename when declaring > it stable to be good thing as it sets an easily identifiable line > in the sand and is self-evident to outside observers. > > The self-documenting nature of the "x-" prefer is what makes it most > compelling to me. A patch submission, or command line invokation or > an example QMP command, or a bug report, that exhibit an 'x-' prefix > are an immediate red flag to anyone who sees them.
Except when it isn't, like in "x-origin". > If someone sees a QMP comamnd / a typical giant QEMU command line, > they are never going to go look at the QAPI schema to check whether > any feature used had an 'unstable' marker. The 'unstable' marker > might as well not exist in most cases. > > IOW, having the 'unstable' flag in the QAPI schema is great for machine > introspection, but it isn't a substitute for having an 'x-' prefix used > for the benefit of humans IMHO. I'm not sure there's disagreement. Quoting myself: The "x-" can remind humans "this is unstable" better than a feature flag can (for machines, it's the other way round). CLI and HMP are for humans. We continue to use "x-" there. QMP is for machines. The feature flag is the sole source of truth. Additional use of "x-" is fine, but not required.