[CentOS-virt] Fwd: Building Xen on RHEL7

Sun Dec 22 06:30:53 UTC 2013
Peter <peter at pajamian.dhs.org>

On 12/22/2013 04:33 PM, Nico Kadel-Garcia wrote:
> My first thought on seeing this thread was "Is there some reason to
> compile from source, rather than from an SRPM, say those at
> http://dev.centos.org/centos/6/xen-c6/SRPMS/ ?"

My thinking is that the sources from F19 would be better since RHEL7 is
based on F19 they would be a lot closer to RHEL7 than the CentOS 6 Xen
sources, although both would probably build with no modifications at all.

One thing that the parent didn't mention is where he got the dom0 kernel
from.  The best place would be just to rebuild the RHEL7 kernel with Xen
dom0 support enabled.  It is possible that libvirt would need to be
rebuilt with Xen support enabled as well, and as I said above,
everything else (the Xen tools and hypervisor) could be gotten from
Fedora 19.

> with the caveat that it did not have a "gcc"
> dependencies, which I've added to a .spec file,

gcc is considered to be part of the standard build toolset and as such
is not required to be listed as a dependency in any spec file.

> and the .spec file for
> dev86 and for Xen both have badly formatted dates in the "%changelog"
> stanza. RHEL 7 is much less tolerant of this  than RHEL 6 was. Again,
> I've edited some .spec files and will try to submit some patches if I
> can fiind time.

The F19 spec files should be fully compliant with the EL7 guidelines.

> Once I'd satisfied all the dependencies for the SRPM, I was able to
> build the Xen 4.3.1  tarball pretty easily. It just didn't work well
> to plug the tarball into the old  SRPM  and .spec file.

Admittedly F19 comes with Xen 4.2.3, rawhide comes with 4.3.1, though,
and can probably be directly rebuilt for EL7 without any fuss.

> But with all that said: why are you bothering with Xen when RHEL and
> thus CentOS have KVM support built right in? Is there some feature you
> require that isn't available in the built-in KVM support?

Some people like Xen, people like a choice, and it's not all that
difficult to add Xen to EL7 anyways.  There's no reason to exclude it
just because upstream made a political decision.