From c21f08f0f6e94ef32a2d36b9aa0aef88b07f821b Mon Sep 17 00:00:00 2001
From: Balazs Gibizer <balazs.gibizer@est.tech>
Date: Mon, 3 Aug 2020 17:02:28 +0200
Subject: [PATCH] Move equality check into LibvirtConfigGuestInterface

This is a pure refactoring that moves the equality check of
LibvirtConfigGuestInterface objects from get_interface_by_cfg() into the
class itself.

Later this pattern will be extended to LibvirtConfigGuestHostdevPCI objects
to support detaching direct physical interfaces where PCI address based
equality is needed.

Part of blueprint sriov-interface-attach-detach

Change-Id: I6ce9457179f65f82ff721b315e51a67ebd879673
---
 nova/virt/libvirt/config.py | 14 ++++++++++++++
 nova/virt/libvirt/guest.py  | 11 +++--------
 2 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
index 32dea36113..083c6f6934 100644
--- a/nova/virt/libvirt/config.py
+++ b/nova/virt/libvirt/config.py
@@ -1686,6 +1686,20 @@ class LibvirtConfigGuestInterface(LibvirtConfigGuestDevice):
         self.device_addr = None
         self.mtu = None
 
+    def __eq__(self, other):
+        if not isinstance(other, LibvirtConfigGuestInterface):
+            return False
+
+        # NOTE(arches) Skip checking target_dev for vhostuser
+        # vif type; target_dev is not a valid value for vhostuser.
+        return (
+            self.mac_addr == other.mac_addr and
+            self.net_type == other.net_type and
+            self.source_dev == other.source_dev and
+            (self.net_type == 'vhostuser' or
+                self.target_dev == other.target_dev) and
+            self.vhostuser_path == other.vhostuser_path)
+
     @property
     def uses_virtio(self):
         return 'virtio' == self.model
diff --git a/nova/virt/libvirt/guest.py b/nova/virt/libvirt/guest.py
index 1a39ce5329..e70989fb69 100644
--- a/nova/virt/libvirt/guest.py
+++ b/nova/virt/libvirt/guest.py
@@ -246,14 +246,9 @@ class Guest(object):
                 # NOTE(leehom) LibvirtConfigGuestInterface get from domain and
                 # LibvirtConfigGuestInterface generated by
                 # nova.virt.libvirt.vif.get_config must be identical.
-                # NOTE(arches) Skip checking target_dev for vhostuser
-                # vif type; target_dev is not a valid value for vhostuser.
-                if (interface.mac_addr == cfg.mac_addr and
-                        interface.net_type == cfg.net_type and
-                        interface.source_dev == cfg.source_dev and
-                        (cfg.net_type == 'vhostuser' or
-                            interface.target_dev == cfg.target_dev) and
-                        interface.vhostuser_path == cfg.vhostuser_path):
+                # NOTE(gibi): LibvirtConfigGuestInterface does a custom
+                # equality check based on available information on nova side
+                if cfg == interface:
                     return interface
 
     def get_vcpus_info(self):