(I've been using the 2008Q1 packages,
on the theory that that's the closest approximation to in sync with
4.0; do newer xen packages (a) work with 4.0 and (b) fix things?)
There's an incompatibility between the latest xentools and the 4.0 release
kernels. So it's current or release but nothing in between :( ... well
reliably anyway.
On a -current dom0 kernel:
The main problem is that xenbackendd isn't invoked at all, therefore the
scripts never run.
xenbackendd listens for XS_WATCH_EVENT, but those never come.
In xen/xenbus/xenbus_xs.c:process_msg I see two type of events:
XS_READ and XS_ERROR for a block device (vbd).