osdict: Turn videomodel check into a function

The previous setup of having an OS register a preferred videomodel is
overly simplistic and doesn't cover all our needs. Rework it without any
logic change for now, we will alter the logic in subsequent commits.

virtinst/guest.py

@@ -507,6 +507,14 @@ class Guest(XMLBuilder):
     # Guest Dictionary Helper methods #
     ###################################
 
+    def _get_os_object(self):
+        ret = osdict.lookup_os(self.os_variant)
+        if ret is None:
+            ret = osdict.lookup_os("generic")
+        return ret
+    _os_object = property(_get_os_object)
+
+
     def _lookup_osdict_key(self, key, default):
         """
         Use self.os_variant to find key in OSTYPES
@@ -960,24 +968,18 @@ class Guest(XMLBuilder):
             dev.type = "spicevmc"
             self.add_device(dev)
 
-    def _set_video_defaults(self):
-        def has_spice():
-            for gfx in self.get_devices("graphics"):
-                if gfx.type == gfx.TYPE_SPICE:
-                    return True
+    def has_spice(self):
+        for gfx in self.get_devices("graphics"):
+            if gfx.type == gfx.TYPE_SPICE:
+                return True
 
-        if has_spice():
+    def _set_video_defaults(self):
+        if self.has_spice():
             self._add_spice_channels()
             self._add_spice_sound()
             self._add_spice_usbredir()
 
-        if has_spice() and self.os.is_x86():
-            video_model = "qxl"
-        elif self.os.is_ppc64() and self.os.machine == "pseries":
-            video_model = "vga"
-        else:
-            video_model = self._lookup_osdict_key("videomodel", "cirrus")
-
+        video_model = self._os_object.get_videomodel(self) or "cirrus"
         for video in self.get_devices("video"):
             if video.model == video.MODEL_DEFAULT:
                 video.model = video_model

virtinst/osdict.py

@@ -157,6 +157,8 @@ class _OSVariant(object):
     based on the OS. They should be self explanatory. See guest.py for
     their usage.
     """
+    _os = None
+
     def __init__(self, name, label, is_type=False,
                  sortby=None, parent=_SENTINEL, typename=_SENTINEL,
                  urldistro=_SENTINEL, supported=_SENTINEL,
@@ -164,7 +166,7 @@ class _OSVariant(object):
                  acpi=_SENTINEL, apic=_SENTINEL, clock=_SENTINEL,
                  netmodel=_SENTINEL, diskbus=_SENTINEL,
                  inputtype=_SENTINEL, inputbus=_SENTINEL,
-                 videomodel=_SENTINEL, virtionet=_SENTINEL,
+                 virtionet=_SENTINEL,
                  virtiodisk=_SENTINEL, virtiommio=_SENTINEL,
                  virtioconsole=_SENTINEL, xen_disable_acpi=_SENTINEL,
                  qemu_ga=_SENTINEL, hyperv_features=_SENTINEL):
@@ -218,7 +220,6 @@ class _OSVariant(object):
         self.clock = _get_default("clock", clock)
 
         self.netmodel = _get_default("netmodel", netmodel)
-        self.videomodel = _get_default("videomodel", videomodel)
         self.diskbus = _get_default("diskbus", diskbus)
         self.inputtype = _get_default("inputtype", inputtype)
         self.inputbus = _get_default("inputbus", inputbus)
@@ -236,6 +237,19 @@ class _OSVariant(object):
         ignore1 = arch
         return None
 
+    def get_videomodel(self, guest):
+        if guest.has_spice() and guest.os.is_x86():
+            return "qxl"
+        if guest.os.is_ppc64() and guest.os.machine == "pseries":
+            return "vga"
+
+        if self._os:
+            if self._os.get_short_id() in {"ubuntu13.10", "ubuntu13.04"}:
+                return "vmvga"
+            if _OsVariantOsInfo.is_windows(self._os):
+                return "vga"
+        return None
+
 
 def _add_type(*args, **kwargs):
     kwargs["is_type"] = True
@@ -286,23 +300,6 @@ class _OsVariantOsInfo(_OSVariant):
             return devs.get_nth(0).get_name()
         return _SENTINEL
 
-    def _get_videomodel(self):
-        if self._os.get_short_id() in {"ubuntu13.10", "ubuntu13.04"}:
-            return "vmvga"
-
-        if _OsVariantOsInfo.is_windows(self._os):
-            return "vga"
-
-        if self._os.get_distro() == "fedora":
-            return _SENTINEL
-
-        fltr = libosinfo.Filter()
-        fltr.add_constraint("class", "video")
-        devs = self._os.get_all_devices(fltr)
-        if devs.get_length():
-            return devs.get_nth(0).get_name()
-        return _SENTINEL
-
     def _get_inputtype(self):
         fltr = libosinfo.Filter()
         fltr.add_constraint("class", "input")
@@ -477,7 +474,6 @@ class _OsVariantOsInfo(_OSVariant):
         hyperv_features = self._is_hyperv_features()
         virtioconsole = lambda: self._is_virtioconsole()
         netmodel = lambda: self._get_netmodel()
-        videomodel = lambda: self._get_videomodel()
         diskbus = lambda: self._get_diskbus()
         inputtype = lambda: self._get_inputtype()
         inputbus = lambda: self.get_inputbus()
@@ -488,7 +484,7 @@ class _OsVariantOsInfo(_OSVariant):
                 urldistro=urldistro, supported=supported,
                 three_stage_install=three_stage_install, acpi=acpi, apic=apic,
                 clock=clock, netmodel=netmodel, diskbus=diskbus,
-                inputtype=inputtype, inputbus=inputbus, videomodel=videomodel,
+                inputtype=inputtype, inputbus=inputbus,
                 virtionet=virtionet, virtiodisk=virtiodisk,
                 virtiommio=virtiommio, virtioconsole=virtioconsole,
                 xen_disable_acpi=xen_disable_acpi, qemu_ga=qemu_ga,
@@ -511,8 +507,9 @@ class _OsVariantOsInfo(_OSVariant):
 
         return ret
 
+
 _add_type("linux", "Linux")
-_add_type("windows", "Windows", clock="localtime", three_stage_install=True, inputtype="tablet", inputbus="usb", videomodel="vga")
+_add_type("windows", "Windows", clock="localtime", three_stage_install=True, inputtype="tablet", inputbus="usb")
 _add_type("solaris", "Solaris", clock="localtime")
 _add_type("unix", "UNIX")
 _add_type("other", "Other")