port-xen/53392: dom0 xen: no poweroff

[yarl-baudig%mailoo.org@localhost]

>Number:         53392
>Category:       port-xen
>Synopsis:       dom0 xen: no poweroff
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    port-xen-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Jun 24 16:35:00 +0000 2018
>Originator:     yarl
>Release:        netbsd-7
>Organization:
>Environment:
NetBSD nb 7.1_STABLE NetBSD 7.1_STABLE (XEN3_DOM0) #8: Sat Jun 23 16:07:26 CEST 2018  builder@nb:/mnt/twoforme/builder/sysbuild/build-stable-debug/amd64/obj/mnt/twoforme/builder/git/src/sys/arch/amd64/compile/XEN3_DOM0 amd64
>Description:
xenkernel48, xentools48

Computer does not poweroff. Neither 'shutdown -p now' nor 'xl shutdown' works.
Disks are synced and devices are detached, nothing more.
This computer powers off fine with a regular kernel.
I didn't touch the kernel configuration.
>How-To-Repeat:

>Fix: