Re: [Fedora-xen] FYI: The plan for Xen kernels in Fedora 9
On Fri, Nov 30, 2007 at 02:44:13PM -0500, Paul Wouters wrote:
On Fri, 30 Nov 2007, Daniel P. Berrange wrote:
> At the same time, upstream Linux gained
> Xen support for i386 DomU, and shortly x86_64 DomU, and is generally
> getting ever more virtualization capabilities.
I am somewhat confused here? Upstream gained xen support but you're forward
porting xen support?
Upstream gained support for i386, DomU Xen support only - that's far from
a complete solution, hence F8 still uses a forward port. This F9 plan is
basically about finishing the upstream Xen to support all the features we
need for Fedora & avoid any more forward porting.
> So the plan is to re-focus 100% of all Xen kernel efforts onto
paravirt_ops.
> LKML already has i386 pv_ops + Xen DomU. We intend to build on this to
> add:
I might be mixing up things, but are you saying you are focussing on adding
paravirt to lguest? And replace xen?
No, lguest is just another user of pv_ops. This is explicitly still a Xen
paravirt solution - we'll still have a Xen 3.x hypervisor underneath, with
same Xen 3.0 hypervisor ABI. So F6/7/8 guests should work on F9 host, and
F9 guest should still work on F6/7/8 host. ABI compatability is key because
that's what makes Xen, Xen :-)
lguest (at this time) is still basically a tool for research & development,
not real world production use.
> What this means though, is that Fedora 9 Xen will certainly be
going through
> periods of instability and will certainly be even buggier than normal. F9
> may well end up lacking features compared to Xen in Fedora 8 & earlier (eg no
> PCI device passthrough, or CPU hotplug). On the plus side though we will be
> 100% back in sync with bare metal kernel versions & hopefully even have a
> lot of this stuff merged in LKML to make ongoing maintainence sustainable.
> Short term pain; Long term gain!
I think most deployments are simple paravirts with no other hardware then virtual
disks and virtual network cards. So that might not be as bad as it sounds.
Yep, we're basically prioritizing our work to address most common & important
areas first. Eventually we may get to stuff like PCI passthrough & CPU hotplug
but its longer term low priority stuff.
Regards,
--
|=- Red Hat, Engineering, Emerging Technologies, Boston. +1 978 392 2496 -=|
|=- Perl modules: http://search.cpan.org/~danberr/ -=|
|=- Projects: http://freshmeat.net/~danielpb/ -=|
|=- GnuPG: 7D3B9505 F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 -=|