What's the right way to address these sort RedHat vs. Debian things in the
Xen build?

- rm -f  $(D)$(CONFIG_DIR)/sysconfig/xendomains
+ rm -f  $(D)$(CONFIG_DIR)/default/xendomains

- mkdir -p /var/lock/subsys
- touch /var/lock/subsys/xend
+ mkdir -p /var/lock
+ touch /var/lock/xend

Can I submit a patch that uses a config var to switch on which path use ?

Or, where should such a build time switch go? Env, or?
...assuming that it's even an option.

There's a couple of different downstream patches that others are maintaining
to handle this kind of stuff, but that lag behind the xen-unstable tree and
it seems like an upstream patch to handle this distro variation in the Xen
build itself would be a better long term solution.

-Bruce