Introduce a class for storing libvirt CPU configuration

Extend the libvirt config APIs to include a new class
LibvirtConfigCPU for storing host/guest CPU configuration
data

blueprint libvirt-xml-config-apis
Change-Id: Ib508637c1e0ca69860d461b0a480347c59165e6b
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

2 files changed, 77 insertions, 0 deletions

diff --git a/nova/tests/test_libvirt_config.py b/nova/tests/test_libvirt_config.py
index 186fb5a18..8d6ede1be 100644
--- a/nova/tests/test_libvirt_config.py
+++ b/nova/tests/test_libvirt_config.py
@@ -361,3 +361,40 @@ class LibvirtConfigGuestTest(LibvirtConfigBaseTest):
                 </disk>
               </devices>
             </domain>""")
+
+
+class LibvirtConfigCPUTest(LibvirtConfigBaseTest):
+
+    def test_config_cpu(self):
+        obj = config.LibvirtConfigCPU()
+        obj.vendor = "AMD"
+        obj.model = "Quad-Core AMD Opteron(tm) Processor 2350"
+        obj.arch = "x86_64"
+        obj.add_feature("svm")
+        obj.add_feature("extapic")
+        obj.add_feature("constant_tsc")
+
+        xml = obj.to_xml()
+        self.assertXmlEqual(xml, """
+            <cpu>
+              <arch>x86_64</arch>
+              <model>Quad-Core AMD Opteron(tm) Processor 2350</model>
+              <vendor>AMD</vendor>
+              <feature name="svm"/>
+              <feature name="extapic"/>
+              <feature name="constant_tsc"/>
+            </cpu>""")
+
+    def test_config_topology(self):
+        obj = config.LibvirtConfigCPU()
+        obj.vendor = "AMD"
+        obj.sockets = 2
+        obj.cores = 4
+        obj.threads = 2
+
+        xml = obj.to_xml()
+        self.assertXmlEqual(xml, """
+            <cpu>
+              <vendor>AMD</vendor>
+              <topology cores="4" threads="2" sockets="2"/>
+            </cpu>""")
diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
index 44790a068..e4f99a7ba 100644
--- a/nova/virt/libvirt/config.py
+++ b/nova/virt/libvirt/config.py
@@ -356,3 +356,43 @@ class LibvirtConfigGuest(LibvirtConfigObject):
 
     def add_device(self, dev):
         self.devices.append(dev)
+
+
+class LibvirtConfigCPU(LibvirtConfigObject):
+
+    def __init__(self, **kwargs):
+        super(LibvirtConfigCPU, self).__init__(root_name="cpu",
+                                               **kwargs)
+
+        self.arch = None
+        self.model = None
+        self.vendor = None
+        self.sockets = None
+        self.cores = None
+        self.threads = None
+        self.features = []
+
+    def add_feature(self, name):
+        self.features.append(name)
+
+    def format_dom(self):
+        cpu = super(LibvirtConfigCPU, self).format_dom()
+        if self.arch:
+            cpu.append(self._text_node("arch", self.arch))
+        if self.model:
+            cpu.append(self._text_node("model", self.model))
+        if self.vendor:
+            cpu.append(self._text_node("vendor", self.vendor))
+        if (self.sockets is not None and
+            self.cores is not None and
+            self.threads is not None):
+            cpu.append(etree.Element("topology",
+                                     sockets=str(self.sockets),
+                                     cores=str(self.cores),
+                                     threads=str(self.threads)))
+
+        for f in self.features:
+            cpu.append(etree.Element("feature",
+                                     name=f))
+
+        return cpu