From 2f6cf7cba883c594e14aea05a85bb36b9f5209b0 Mon Sep 17 00:00:00 2001
From: "Daniel P. Berrange" <berrange@redhat.com>
Date: Tue, 28 Jul 2015 17:39:33 +0100
Subject: [PATCH] libvirt: add helper methods for getting guest devices/disks

Add get_all_devices and get_all_disks methods to the libvirt
Guest object.

Related-bug: #1429220
Change-Id: I97ee786c5cc603aec1695929f58aa127063db439
---
 nova/tests/unit/virt/libvirt/test_guest.py | 87 ++++++++++++++++++++++
 nova/virt/libvirt/guest.py                 | 30 ++++++++
 2 files changed, 117 insertions(+)

diff --git a/nova/tests/unit/virt/libvirt/test_guest.py b/nova/tests/unit/virt/libvirt/test_guest.py
index 79164530aa1a..35d643bc4a11 100644
--- a/nova/tests/unit/virt/libvirt/test_guest.py
+++ b/nova/tests/unit/virt/libvirt/test_guest.py
@@ -257,6 +257,93 @@ class GuestTestCase(test.NoDBTestCase):
         self.guest.set_user_password("foo", "123")
         self.domain.setUserPassword.assert_called_once_with("foo", "123", 0)
 
+    def test_get_devices(self):
+        xml = """
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory unit='KiB'>219136</memory>
+  <currentMemory unit='KiB'>219136</currentMemory>
+  <vcpu placement='static'>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest2'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
+    </disk>
+    <disk type='network' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <auth username='myname'>
+        <secret type='iscsi' usage='mycluster_myname'/>
+      </auth>
+      <source protocol='iscsi' name='iqn.1992-01.com.example'>
+        <host name='example.org' port='6000'/>
+      </source>
+      <target dev='vda' bus='virtio'/>
+    </disk>
+    <disk type='network' device='disk'>
+      <driver name='qemu' type='raw'/>
+      <source protocol='iscsi' name='iqn.1992-01.com.example/1'>
+        <host name='example.org' port='6000'/>
+      </source>
+      <target dev='vdb' bus='virtio'/>
+    </disk>
+    <hostdev mode='subsystem' type='pci' managed='yes'>
+      <source>
+        <address domain='0x0000' bus='0x06' slot='0x12' function='0x5'/>
+      </source>
+    </hostdev>
+    <hostdev mode='subsystem' type='pci' managed='yes'>
+      <source>
+        <address domain='0x0000' bus='0x06' slot='0x12' function='0x6'/>
+      </source>
+    </hostdev>
+    <controller type='usb' index='0'/>
+    <controller type='pci' index='0' model='pci-root'/>
+    <memballoon model='none'/>
+  </devices>
+</domain>
+"""
+
+        self.domain.XMLDesc.return_value = xml
+
+        devs = self.guest.get_all_devices()
+        # Only currently parse <disk> and <hostdev> elements
+        # hence we're not counting the controller/memballoon
+        self.assertEqual(5, len(devs))
+        self.assertIsInstance(devs[0], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[1], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[2], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[3], vconfig.LibvirtConfigGuestHostdev)
+        self.assertIsInstance(devs[4], vconfig.LibvirtConfigGuestHostdev)
+
+        devs = self.guest.get_all_devices(vconfig.LibvirtConfigGuestDisk)
+        self.assertEqual(3, len(devs))
+        self.assertIsInstance(devs[0], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[1], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[2], vconfig.LibvirtConfigGuestDisk)
+
+        devs = self.guest.get_all_disks()
+        self.assertEqual(3, len(devs))
+        self.assertIsInstance(devs[0], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[1], vconfig.LibvirtConfigGuestDisk)
+        self.assertIsInstance(devs[2], vconfig.LibvirtConfigGuestDisk)
+
+        devs = self.guest.get_all_devices(vconfig.LibvirtConfigGuestHostdev)
+        self.assertEqual(2, len(devs))
+        self.assertIsInstance(devs[0], vconfig.LibvirtConfigGuestHostdev)
+        self.assertIsInstance(devs[1], vconfig.LibvirtConfigGuestHostdev)
+
 
 class GuestBlockTestCase(test.NoDBTestCase):
 
diff --git a/nova/virt/libvirt/guest.py b/nova/virt/libvirt/guest.py
index 9264206eb190..d0a975f8b8df 100644
--- a/nova/virt/libvirt/guest.py
+++ b/nova/virt/libvirt/guest.py
@@ -217,6 +217,36 @@ class Guest(object):
             conf.parse_dom(node)
             return conf
 
+    def get_all_disks(self):
+        """Returns all the disks for a guest
+
+        :returns: a list of LibvirtConfigGuestDisk instances
+        """
+
+        return self.get_all_devices(vconfig.LibvirtConfigGuestDisk)
+
+    def get_all_devices(self, devtype=None):
+        """Returns all devices for a guest
+
+        :param devtype: a LibvirtConfigGuestDevice subclass class
+
+        :returns: a list of LibvirtConfigGuestDevice instances
+        """
+
+        try:
+            config = vconfig.LibvirtConfigGuest()
+            config.parse_str(
+                self._domain.XMLDesc(0))
+        except Exception:
+            return []
+
+        devs = []
+        for dev in config.devices:
+            if (devtype is None or
+                isinstance(dev, devtype)):
+                devs.append(dev)
+        return devs
+
     def detach_device(self, conf, persistent=False, live=False):
         """Detaches device to the guest.