[CentOS-virt] Plan to update to Xen 4.6

Tue Nov 3 17:04:45 UTC 2015
George Dunlap <dunlapg at umich.edu>

When we started the Virt SIG, our stated goal was to support one
recent version of Xen with a recent kernel.  We updated at that time
to Xen 4.4, as the most recent stable release.  We skipped 4.5; but
now with 4.6 out, I think it's about time to upgrade.

Moving to 4.6 has several distinct advantages for CentOS 7.  Xen 4.4
has no systemd integration, while Xen 4.6 does.  Additionally, Xen 4.4
has an insufficient level of ARM support, while Xen 4.6 does.

The Xen releases are heavily tested upstream, not only by the
open-source team, but by the vendors who build their products on Xen.
I'm fairly confident that moving forward to Xen 4.6 should be a
relatively safe maneuver for most people.

So I shall be moving towards releasing Xen 4.6 for CentOS 6 in the not
too distant future.

That said, the Virt SIG is a community effort -- if anyone in the
community wants to step up and maintain the Xen 4.4 packages within
the SIG, they would be welcome to do so.  The burden of doing the
maintenance should not be too high.

Security updates will continue for 4.4 until the 4.6 packages are
fully ready (and may continue for a month or  two afterwards,
depending on severity, to provide a transition period).