From: Cole Robinson <crobinso@redhat.com>
Date: Thu, 26 Mar 2015 17:08:15 -0400
Subject: [PATCH virt-manager] cpu: Drop vendor and features if setting
 host-model (bz 1190851)

Otherwise via virt-manager we can try to set a <cpu> with a <vendor>
but no <model>, and libvirt complains.

(cherry picked from commit dc1737e623aef0f661cc28c0c5b87f847fc2526b)
---
 tests/xmlparse-xml/change-minimal-guest-out.xml | 2 +-
 tests/xmlparse.py                               | 1 +
 virtinst/cpu.py                                 | 5 +++++
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/tests/xmlparse-xml/change-minimal-guest-out.xml b/tests/xmlparse-xml/change-minimal-guest-out.xml
index 5363080..f3be5c0 100644
--- a/tests/xmlparse-xml/change-minimal-guest-out.xml
+++ b/tests/xmlparse-xml/change-minimal-guest-out.xml
@@ -23,7 +23,7 @@
     <label>frob</label>
   </seclabel>
   <cpu mode="custom" match="exact">
-    <model>foobar</model>
+    <model fallback="allow">foobar</model>
     <topology sockets="1" cores="4" threads="1"/>
     <feature policy="forbid" name="x2apic"/>
   </cpu>
diff --git a/tests/xmlparse.py b/tests/xmlparse.py
index c4bcb20..477de22 100644
--- a/tests/xmlparse.py
+++ b/tests/xmlparse.py
@@ -251,6 +251,7 @@ class XMLParseTest(unittest.TestCase):
 
         check = self._make_checker(guest.cpu)
         check("model", None, "foobar")
+        check("model_fallback", None, "allow")
         check("cores", None, 4)
         guest.cpu.add_feature("x2apic", "forbid")
         guest.cpu.set_topology_defaults(guest.vcpus)
diff --git a/virtinst/cpu.py b/virtinst/cpu.py
index 551364c..b12fd30 100644
--- a/virtinst/cpu.py
+++ b/virtinst/cpu.py
@@ -59,6 +59,10 @@ class CPU(XMLBuilder):
         if (val == self.SPECIAL_MODE_HOST_MODEL or
             val == self.SPECIAL_MODE_HOST_PASSTHROUGH):
             self.model = None
+            self.vendor = None
+            self.model_fallback = None
+            for f in self.features:
+                self.remove_feature(f)
             self.mode = val
         elif val == self.SPECIAL_MODE_HOST_COPY:
             self.copy_host_cpu()
@@ -161,6 +165,7 @@ class CPU(XMLBuilder):
                 self.match = "exact"
         return val
     model = XMLProperty("./model", set_converter=_set_model)
+    model_fallback = XMLProperty("./model/@fallback")
 
     match = XMLProperty("./@match")
     vendor = XMLProperty("./vendor")