Re: [libvirt] [PATCH 7/7] Add support for attaching network/bridge NICs in QEMU driver
On Mon, Jul 27, 2009 at 10:18:18PM +0100, Daniel P. Berrange wrote:
It is also probably worth formalizing how long we wish to support a
particular hypervisor release series for.
ie how long do we wish to support Xen 3.0.3 for (for benefit of
RHEL-5) before we declare only Xen 3.1.0 or later & thus drop
all the crufty xm_internal.c code.
As a starting point I'd say we should support a particular HV
release for as long as it is shipped in the current release of
a major distro. ie we'd support Xen 3.0.3 for as long as RHEL-5
was most recent, and once RHEL-6 came out we'd drop Xen 3.0.3
support, picking the next oldest Xen version that's used in a
current major distro whether that's 3.1.0 or 3.3.0 or something
else. This would allow distro maintainers reasonably easy
backports and/or rebases to newer libvirt versions for some
amount of time, without burdening us (upstream) to support ancient
versions of Xen / QEMU forever.
This thread is probably not the best place to discuss that policy,
and should be started separately. I tend to think that it depends how
intrusive the specific bits are to manage an old hypervisor version.
If it doesn't hurt, except for the size IMHO there is no reason to drop
support, it's only if the associated code makes maintainance harder than
necessary that it should be dropped. For example in xm_internal.c case
as long as it's cleanly separated and doesn't make patches for new
versions more complex, I would keep it. Another example is old Xen
hypervisor code, we have that big detection code and switch but beside
that it's not making other things any more complex. The goal of libvirt
being really to decouple from low level changes and simplify long term
maintainance, I would be very conservative and drop ancien versions
support only if it really gets painful and we are pretty sure there is
no real users left. I consider the project users the final users, not
the distro maintainers !
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
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http://veillard.com/ | virtualization library http://libvirt.org/