preserve secure information on xml changes

When setting parameters revolving around boot
mode, options, firmware, it is necessary to
extract and edit the XML document.

Some details, however, are not automatically
extracted and libvirt must be told to provide
secure information. This change prevents us
from accidently loosing such configuration
parameters

Story: 2010382
Task: 46652

Change-Id: I562e19a4290df64010ef59f6c5d9f49aeb09a693

releasenotes/notes/preserve-libvirt-domain-info-955410f570060241.yaml

@@ -0,0 +1,10 @@
+---
+security:
+  - |
+    Secure information in the Libvirt domain XML document is now preserved.
+    For more information, please see `story 2010382
+    <https://storyboard.openstack.org/#!/story/2010382>`_.
+fixes:
+  - |
+    Fixes an issue where secure fields were accidently lost in the Libvirt
+    domain XML document.

sushy_tools/emulator/resources/systems/libvirtdriver.py

@@ -189,6 +189,20 @@ class LibvirtDriver(AbstractSystemsDriver):
 
             raise error.AliasAccessError(domain.UUIDString())
 
+    # Copied from nova/virt/libvirt/guest.py
+    def get_xml_desc(self, domain, dump_inactive=True,
+                     dump_sensitive=True):
+        """Returns xml description of guest.
+
+        :param dump_inactive: Dump inactive domain information
+        :param domain: The libvirt domain to call
+        :param dump_sensitive: Dump security sensitive information
+        :returns string: XML description of the guest
+        """
+        flags = dump_inactive and libvirt.VIR_DOMAIN_XML_INACTIVE or 0
+        flags |= dump_sensitive and libvirt.VIR_DOMAIN_XML_SECURE or 0
+        return domain.XMLDesc(flags=flags)
+
     @property
     def driver(self):
         """Return human-friendly driver information
@@ -386,7 +400,7 @@ class LibvirtDriver(AbstractSystemsDriver):
         domain = self._get_domain(identity)
 
         # XML schema: https://libvirt.org/formatdomain.html#elementsOSBIOS
-        tree = ET.fromstring(domain.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE))
+        tree = ET.fromstring(self.get_xml_desc(domain))
 
         # Remove bootloader configuration
 
@@ -492,7 +506,7 @@ class LibvirtDriver(AbstractSystemsDriver):
         domain = self._get_domain(identity, readonly=True)
 
         # XML schema: https://libvirt.org/formatdomain.html#elementsOSBIOS
-        tree = ET.fromstring(domain.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE))
+        tree = ET.fromstring(self.get_xml_desc(domain))
 
         try:
             loader_type = self.BOOT_MODE_MAP[boot_mode]
@@ -1062,8 +1076,7 @@ class LibvirtDriver(AbstractSystemsDriver):
         """
         domain = self._get_domain(identity)
 
-        domain_tree = ET.fromstring(
-            domain.XMLDesc(libvirt.VIR_DOMAIN_XML_INACTIVE))
+        domain_tree = ET.fromstring(self.get_xml_desc(domain))
 
         self._remove_boot_images(domain, domain_tree, device)