Reference: bnc#863821
grub.xen is required to boot PV VMs that use the BTRFS filesystem.
This patch forces the use of grub.xen (instead of using pygrub) for
suse distros SLE12GA, openSUSE 13.2, and newer.
Index: virt-manager-4.0.0/virtinst/install/installer.py
===================================================================
--- virt-manager-4.0.0.orig/virtinst/install/installer.py
+++ virt-manager-4.0.0/virtinst/install/installer.py
@@ -222,7 +222,8 @@ class Installer(object):
 
     def _alter_treemedia_bootconfig(self, guest):
         if not self._treemedia:
-            return
+            if not self._treemedia_bootconfig or "grub.xen" not in self._treemedia_bootconfig[0]:
+                return
 
         kernel, initrd, kernel_args = self._treemedia_bootconfig
         if kernel:
@@ -582,6 +583,21 @@ class Installer(object):
         final_xml = guest.get_xml()
         if self._requires_postboot_xml_changes():
             initial_xml, final_xml = self._build_postboot_xml(final_xml, meter)
+        if (guest.os.is_xenpv() and
+            not guest.os.kernel):
+            os_ver = guest.osinfo.name
+            if guest.os.arch != 'x86_64' or os_ver.startswith("sles9") or \
+               os_ver.startswith("sles10") or os_ver.startswith("sled10") or \
+               os_ver.startswith("opensuse10") or os_ver.startswith("opensuse11"):
+                guest.bootloader = "pygrub"
+            else:
+                guest.bootloader = None
+                self._treemedia_bootconfig = ("/usr/lib/grub2/x86_64-xen/grub.xen", "", "")
+                log.debug("Using grub.xen to boot guest")
+                on_reboot_value = guest.on_reboot
+                self._alter_bootconfig(guest)
+                guest.on_reboot = on_reboot_value
+                final_xml = guest.get_xml()
         final_xml = self._pre_reinstall_xml or final_xml
 
         log.debug("Generated initial_xml: %s",