Description of problem:
Selected a virtio drive as install target on s390x

Version-Release number of selected component:
anaconda-20.25.15-1

The following was filed automatically by anaconda:
anaconda 20.25.15-1 exception report
Traceback (most recent call first):
  File "/usr/lib64/python2.7/site-packages/pyanaconda/bootloader.py", line 533, in device_description
    raise ValueError("No description available for %s" % device.type)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/bootloader.py", line 581, in is_valid_stage1_device
    description = self.device_description(device)
  File "/usr/lib/python2.7/site-packages/blivet/partitioning.py", line 117, in _schedulePartitions
    if storage.bootloader.is_valid_stage1_device(device, early=True):
  File "/usr/lib/python2.7/site-packages/blivet/partitioning.py", line 315, in doAutoPartition
    _schedulePartitions(storage, disks)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/kickstart.py", line 263, in execute
    doAutoPartition(storage, ksdata)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/kickstart.py", line 1746, in doKickstartStorage
    ksdata.autopart.execute(storage, ksdata, instClass)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/tui/spokes/storage.py", line 260, in execute
    doKickstartStorage(self.storage, self.data, self.instclass)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/tui/spokes/storage.py", line 215, in input
    self.execute()
  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/tui/simpleline/base.py", line 440, in input
    key = self._screens[-1][0].input(args, key)
ValueError: No description available for disk

Additional info:
cmdline:        /usr/bin/python  /sbin/anaconda
cmdline_file:   root=live:http://s390.koji.fedoraproject.org/tree/releases/20/Fedora/s390x/os/images/install.img ip=192.168.53.2:192.168.53.1:192.168.53.1:32:s390x.kvm:eth0:none nameserver=8.8.8.8
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         3.11.10-301.fc20.s390x
product:        Fedora
release:        Cannot get release name.
type:           anaconda
version:        20