[Fedora-xen] [fedora-virt] Dom0 xen support in Fedora 15?

[Don Dutile]

M A Young wrote:
> I am trying to work out whether it is practical to propose Dom0 xen 
> support as a feature for Fedora 15.
> 
> The kernel situation is that Domain 0 has been accepted upstream for 
> 2.6.37. Assuming a 3 month kernel release cycle, F15 will most likely ship 
> with a 2.6.37.x kernel, with 2.6.38 coming out either after the F15 
> release or just before but too late to be included. If the plan to get key 
> xen drivers into 2.6.38 succeeds, then F15 may be become usable as a 
> Domain 0 system at some point during its lifetime as the kernel package in 
> a Fedora version typically has one major update.
> 
> If the kernel team accept backported patches then it might just be 
> possible to ship F15 with usable Domain 0 support but the timescale for 
> that would be very tight.
> 
> The other thing we would need to consider is what needs to be done to make 
> xen friendly enough to be usable by an ordinary user. The page 
> https://fedoraproject.org/wiki/Features/XenPvopsDom0 contains plans from 
> when dom0 xen support was expected to make a quick return to Fedora, but 
> they are a couple of years old now so probably need updating.
> 
> I think as a minimum we would need a way to add a dom0 enabled grub entry 
> for a kernel, rather than requiring the user to hand edit the grub file. 
> We should also make sure that xen works with the other Fedora 
> virtualisation tools.
> 
> What do others think about this? For example is it achievable as a 
> feature, is it too early and better to wait for F16, and what else should 
> we aim to do to make xen usable in Fedora?
> 
>  	Michael Young
> _______________________________________________
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> virt at lists.fedoraproject.org
> https://admin.fedoraproject.org/mailman/listinfo/virt

IMO, the pieces that the Xen folks have to whip into shape are the tools;
the missing kernel pieces are fairly well known (backend drivers), although Xen folks
are considering blkback in userspace instead of kernel space, so that may be
a new twist.

So, getting Xen support in the following 2 userspace tools is critical: qemu & libvirt;
the latter means a new interface to xen libxc (dropping xend), so xen fixes can be
tracked to latest xen upstream.  I've seen a fair amt of activity to add xen support
to upstream qemu; I haven't been following libvirt devel to see if xen support to
libxc has been active or not (but would like to hear if so).

- Don