[urgent] Soft Feature Freeze has started since Nov.1 for dk2-stable201811

[Laszlo Ersek <lersek@redhat.com>]

+ Yuchenlin, + Gerd, + both Phils

On 11/07/18 20:13, Laszlo Ersek wrote:

>>> For example, I reviewed and pushed 4 patches yesterday (on 2018-Nov-06):
>>>
>>>   1  e038bde2679b Revert "OvmfPkg/QemuVideoDxe: list "UnalignedIoInternal.h" in the INF file"
>>>   2  98856a724c2a Revert "OvmfPkg/QemuVideoDxe: VMWare SVGA device support"
>>>   3  438ada5aa5a1 Revert "OvmfPkg/QemuVideoDxe: Helper functions for unaligned port I/O."
>>>   4  328409ce8de7 Revert "OvmfPkg: VMWare SVGA display device register definitions"
>>>
>>> which are the first four patches (out of five) from the following
>>> series:
>>>
>>>   [edk2] [PATCH v2 0/5] OvmfPkg: simply use the Bochs interface for vmsvga
>>>
>>> These reverts are arguably not bugfixes; they are preparation for
>>> re-implementing a feature from scratch (the last patch in that series).
>>> Thus, had I known we were already in the Soft Feature Freeze, I wouldn't
>>> have pushed them, because the review was not complete before the soft
>>> freeze start.
>>>
>>> But I had just returned from a week (or more) of PTO, there was no
>>> announcement on the list yet, and I didn't remember the wiki page.
>>>
>>> (In the technical sense, the reverts are not disruptive, luckily; they
>>> remove code that is dead anyway.)

I've given this more thought.

The reverts indeed remove dead code, but the code in question is dead
*only* on QEMU v2.10+. On QEMU v2.9 and earlier, the code is not dead.

(See the original discussion in the thread "[edk2] [PATCH] OvmfPkg:
initialize bochs when initializing vmsvga".)

This means that, with only the first four patches applied from the
series (= the reverts), and with the fifth patch (= the clean
re-implementation of the feature) postponed, people running
edk2-stable201811 on *old* -- v2.9 or older -- QEMU, with VMW SVGA, will
suffer a regression.

So that leaves me with a question. Should I revert the first four
patches now, for edk2-stable201811? (I.e., revert the reverts -->
re-instate the incorrect VMW SVGA driver impl, that happens to work on
v2.9 and earlier.)

... Note that upstream QEMU no longer supports (= maintains stable
branches) for v2.9 and earlier releases. The QEMU homepage
<https://www.qemu.org/> currently advertizes:
- 3.1.0-rc0
- 3.0.0
- 2.12.1
- 2.11.2

Personally I'm leaning towards keeping the reverts for
edk2-stable201811. (v2.9 is really old, and the VMW SVGA device model is
virtually unused.) For my professional integrity though, I must ask this
question publicly.

Thanks
Laszlo