I want to use gcdemu and I did the following:
  zypper in gcdemu
  modprobe vhba
then in a terminal i typed
  gcdemu
The program didn't start and showed me the following error message:

Traceback (most recent call last):
  File "/usr/bin/gcdemu", line 1889, in on_connection_established
    self.add_device(i)
  File "/usr/bin/gcdemu", line 1931, in add_device
    device = self.create_device(self.cdemu, num)
  File "/usr/bin/gcdemu", line 2035, in create_device
    return gCDEmuDevice_Indicator(cdemu, d)
  File "/usr/bin/gcdemu", line 1677, in __init__
    gCDEmuDevice.__init__(self, cdemu, d)
  File "/usr/bin/gcdemu", line 1444, in __init__
    self.file_chooser = gCDEMuFileChooserDialog(cdemu.supported_parsers,
cdemu.supported_filter_streams)
  File "/usr/bin/gcdemu", line 961, in __init__
    Gtk.FileChooserDialog.__init__(self, _("Open file"), None,
Gtk.FileChooserAction.OPEN, (_("Cancel"), Gtk.ResponseType.CANCEL, _("Open"),
Gtk.ResponseType.ACCEPT))
TypeError: GObject.__init__() takes exactly 0 arguments (4 given)

It turns out that gcdemu requires python3 but the first line in /usr/bin/gcdemu
is:
  #!/usr/bin/env python
which uses python2
changing such line to:
  #!/usr/bin/env python3
makes gcdemu work properly.