Description of problem:
Xen guest is shutdown when first starting libvirtd.service.

Version-Release number of selected component (if applicable):
kernel-4.9.0-0.rc6.git2.1.fc26.x86_64
libvirt-3.0.0-1.fc26.x86_64
xen-4.8.0-2.fc26.x86_64

How reproducible: Always

Steps to Reproduce:
1. Boot Fedora Rawhide system xen hypervisor.
2. Create a vm guest using command "xl create xen-guest.conf"
3. Using “xl list” to check the guest status, login to guest and the guest works OK.
4. Start libvirtd.service, check the guest status by xl list.

Actual results:
Xen guest is shutdown when executing command "service libvirtd start", the status changing like this:
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----      36.4
xen-hvm-32                                   1  1024     2     -b----       0.2
[root@dhcp-10-249 ~]# service libvirtd status
Redirecting to /bin/systemctl status  libvirtd.service
● libvirtd.service - Virtualization daemon
   Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled; vendor pre
   Active: inactive (dead)
     Docs: man:libvirtd(8)
           http://libvirt.org
[root@dhcp-10-249 ~]# service libvirtd start
Redirecting to /bin/systemctl start  libvirtd.service
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----      42.0
xen-hvm-32                                   1  1024     2     ---ss-       0.4
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----      45.0
xen-hvm-32                                   1  1024     2     --pss-       0.4
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----      46.3
(null)                                       1  1024     2     --pss-       0.4
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----      48.0
(null)                                       1  1024     2     --pss-       0.4
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----      50.0
(null)                                       1  1024     2     --pss-       0.4
[root@dhcp-10-249 ~]# xl list
Name                                        ID   Mem VCPUs        State        Time(s)
Domain-0                                     0  6916     8     r-----     103.6


Expected results:
The libvirtd service shouldn't affect xen guest status.

Additional information:
1. Creating xen guest again, and then restart or stop/start libvirtd.service again, the guest status isn't affected. So xen guest is shutdown only when first starting libvirtd.service after booting host.
2. The xen guest logs displays the guest is shutdown:
   Waiting for domain xen-hvm-32 (domid 1) to die [pid 1634]
   Domain 1 has shut down, reason code 2 0x2
   Domain has suspended.
   Done. Exiting now