move nova-ovs-hybrid-plug to deploy with spice and fix qxl default

In centos/rhel 9 qemu supprot for the qxl model was removed
with the removal of spice support.
In ubuntu 24.04 qemu support for qxl and spice supprot
has now also been removed.
debian 12 bookworm still support spice in there qemu package.

When we updated the default video model to virtio for x86 we
left a config driven special case for spice to default to qxl
since that nolonger works on centos or ubuntu based distos that
default is not helpful so this change removes the special case
making virtio the default for x86 regardless of the console used.

This change also updates the nova-ovs-hybrid-plug to test with spice
so that we have at least one job using it. to enable that the job is
moved to debian.

Closes-Bug: #2097529
Change-Id: I265ad2ced3729bed41bf53c58dcebadb775ce1f7

.zuul.yaml

@@ -143,6 +143,7 @@
 - job:
     name: nova-ovs-hybrid-plug
     parent: tempest-multinode-full-py3
+    nodeset: devstack-two-node-debian-bookworm
     description: |
       Run move operations, reboot, and evacuation (via the same post-run hook
       as the nova-live-migration job) tests with the OVS network backend and
@@ -175,6 +176,7 @@
         Q_ML2_TENANT_NETWORK_TYPE: vxlan
         Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
         ML2_L3_PLUGIN: router
+        NOVA_VNC_ENABLED: False
       devstack_services:
         # Disable OVN services
         br-ex-tcpdump: false
@@ -202,6 +204,9 @@
         s-object: false
         s-proxy: false
         openstack-cli-server: true
+        # disable vnc and enable spice
+        n-novnc: false
+        n-spice: true
       devstack_local_conf:
         post-config:
           "/$NEUTRON_CORE_PLUGIN_CONF":
@@ -220,6 +225,8 @@
           Q_ML2_TENANT_NETWORK_TYPE: vxlan
           Q_ML2_PLUGIN_MECHANISM_DRIVERS: openvswitch
           ML2_L3_PLUGIN: router
+          NOVA_VNC_ENABLED: False
+          NOVA_SPICE_ENABLED: true
         devstack_services:
           # Disable OVN services
           br-ex-tcpdump: false

nova/tests/unit/virt/libvirt/test_driver.py

@@ -6077,8 +6077,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.flags(pointer_model='usbtablet')
 
         video_map = {
-            fields.Architecture.X86_64: 'qxl',
-            fields.Architecture.I686: 'qxl',
+            fields.Architecture.X86_64: 'virtio',
+            fields.Architecture.I686: 'virtio',
             fields.Architecture.PPC: 'vga',
             fields.Architecture.PPC64: 'vga',
             fields.Architecture.PPC64LE: 'vga',

nova/virt/libvirt/driver.py

@@ -6768,8 +6768,6 @@ class LibvirtDriver(driver.ComputeDriver):
             return 'virtio'
         elif guestarch == fields.Architecture.MIPSEL:
             return 'virtio'
-        elif CONF.spice.enabled:
-            return 'qxl'
 
         # NOTE(lyarwood): Return None and default to the default of
         # LibvirtConfigGuestVideo.type that is currently virtio

releasenotes/notes/make-virtio-the-default-spice-video-model-fff5189fa637d4bd.yaml

@@ -0,0 +1,24 @@
+---
+upgrade:
+  - |
+    Ubuntu 24.04 does not support the QXL video model or spice.
+    Operators using instances with this video model will be unable to start
+    them if moving to Ubuntu 24.04. CentOS 9 and RHEL 9 previously compiled
+    out support for spice, and as QXL was implemented in libspice, support
+    for QXL was removed as a result for the removal of support for spice.
+    The QXL model was a spice optimized video model and is no longer
+    supported by several distros. To avoid issues with starting instances,
+    operators should change the spice video model from QXL to virtio and
+    replace the spice console with vnc. For existing instances the video
+    model can be updated with the ``nova-manage image_property set`` command.
+    when updating the embedded image properties Operators should evaluate if
+    any glance images request the QXL video model and update them or work
+    with the image owner to have them move to a modern video model.
+fixes:
+  - |
+    When the default video model for libvirt was updated to virtio in Yoga
+    the default for host using spice was not changed. This lead to issues
+    when starting instances on hosts that had spice configured with QXL as
+    the default video model on modern distros. To address this the default
+    spice video model is now virtio.
+    see https://bugs.launchpad.net/nova/+bug/2097529 for more details.