docs/system: clarify deprecation schedule

The sentence explaining the deprecation schedule is ambiguous. Make it
clear that a feature deprecated in the Nth release is guaranteed to
remain available in the N+1th release. Removal can occur in the N+2nd
release or later.

As an example of this in action, see commit
25956af3fe ("block: Finish deprecation of
'qemu-img convert -n -o'"). The feature was deprecated in QEMU 4.2.0. It
was present in the 5.0.0 release and removed in the 5.1.0 release.

Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200915150734.711426-1-stefanha@redhat.com>
This commit is contained in:
Stefan Hajnoczi 2020-09-15 16:07:34 +01:00
parent 8080747748
commit ef1f5b0a96

View File

@ -3,10 +3,11 @@ Deprecated features
In general features are intended to be supported indefinitely once
introduced into QEMU. In the event that a feature needs to be removed,
it will be listed in this section. The feature will remain functional
for 2 releases prior to actual removal. Deprecated features may also
generate warnings on the console when QEMU starts up, or if activated
via a monitor command, however, this is not a mandatory requirement.
it will be listed in this section. The feature will remain functional for the
release in which it was deprecated and one further release. After these two
releases, the feature is liable to be removed. Deprecated features may also
generate warnings on the console when QEMU starts up, or if activated via a
monitor command, however, this is not a mandatory requirement.
Prior to the 2.10.0 release there was no official policy on how
long features would be deprecated prior to their removal, nor