diff --git a/manifests/compute/libvirt.pp b/manifests/compute/libvirt.pp
index 98d69f5a8..918ce8e83 100644
--- a/manifests/compute/libvirt.pp
+++ b/manifests/compute/libvirt.pp
@@ -361,7 +361,7 @@ class nova::compute::libvirt (
     }
   }
 
-  if $libvirt_cpu_mode_real != 'none' {
+  if $libvirt_cpu_mode_real != 'none' and $libvirt_cpu_model_extra_flags {
     validate_legacy(String, 'validate_string', $libvirt_cpu_model_extra_flags)
     nova_config {
       'libvirt/cpu_model_extra_flags': value => $libvirt_cpu_model_extra_flags;
diff --git a/spec/classes/nova_compute_libvirt_spec.rb b/spec/classes/nova_compute_libvirt_spec.rb
index 4e525fbc2..c55e00037 100644
--- a/spec/classes/nova_compute_libvirt_spec.rb
+++ b/spec/classes/nova_compute_libvirt_spec.rb
@@ -14,9 +14,7 @@ describe 'nova::compute::libvirt' do
     describe 'with default parameters' do
 
       let :params do
-        {
-          :libvirt_cpu_model_extra_flags  => 'pcid,pdpe1gb',
-        }
+        {}
       end
 
       it { is_expected.to contain_class('nova::params')}
@@ -32,7 +30,7 @@ describe 'nova::compute::libvirt' do
 
       it {
         is_expected.to contain_package('libvirt').with(
-          :name   => 'libvirtd',
+          :name   => 'libvirt-bin',
           :ensure => 'present'
         )
         is_expected.to contain_package('libvirt').that_requires('Anchor[nova::install::begin]')
@@ -52,8 +50,8 @@ describe 'nova::compute::libvirt' do
       it { is_expected.to contain_nova_config('libvirt/virt_type').with_value('kvm')}
       it { is_expected.to contain_nova_config('libvirt/cpu_mode').with_value('host-model')}
       it { is_expected.to contain_nova_config('libvirt/cpu_model').with_ensure('absent')}
-      it { is_expected.to contain_nova_config('libvirt/cpu_model_extra_flags').with_ensure('pcid,pdpe1gb')}
-      it { is_expected.to contain_nova_config('libvirt/snapshot_image_format').with_ensure('absent')}
+      it { is_expected.to contain_nova_config('libvirt/cpu_model_extra_flags').with_ensure('absent')}
+      it { is_expected.to contain_nova_config('libvirt/snapshot_image_format').with_value('<SERVICE DEFAULT>')}
       it { is_expected.to contain_nova_config('libvirt/disk_cachemodes').with_ensure('absent')}
       it { is_expected.to contain_nova_config('libvirt/inject_password').with_value(false)}
       it { is_expected.to contain_nova_config('libvirt/inject_key').with_value(false)}
@@ -65,13 +63,13 @@ describe 'nova::compute::libvirt' do
       it { is_expected.to contain_nova_config('libvirt/rx_queue_size').with_value('<SERVICE DEFAULT>')}
       it { is_expected.to contain_nova_config('libvirt/tx_queue_size').with_value('<SERVICE DEFAULT>')}
       it { is_expected.to contain_nova_config('libvirt/volume_use_multipath').with_value('<SERVICE DEFAULT>')}
-      it { is_expected.to contain_nova_config('libvirt/nfs_mount_options').with_ensure('<SERVICE DEFAULT>')}
-      it { is_expected.to contain_nova_config('libvirt/num_pcie_ports').with_ensure('<SERVICE DEFAULT>')}
+      it { is_expected.to contain_nova_config('libvirt/nfs_mount_options').with_value('<SERVICE DEFAULT>')}
+      it { is_expected.to contain_nova_config('libvirt/num_pcie_ports').with_value('<SERVICE DEFAULT>')}
       it { is_expected.to contain_nova_config('libvirt/mem_stats_period_seconds').with_value('<SERVICE DEFAULT>')}
+      it { is_expected.to contain_nova_config('libvirt/pmem_namespaces').with_value('<SERVICE DEFAULT>')}
       it { is_expected.to contain_libvirtd_config('log_outputs').with_ensure('absent')}
       it { is_expected.to contain_libvirtd_config('log_filters').with_ensure('absent')}
       it { is_expected.to contain_libvirtd_config('tls_priority').with_ensure('absent')}
-      it { is_expected.to contain_libvirtd_config('pmem_namespaces').with_ensure('<SERVICE DEFAULT>')}
     end
 
     describe 'with params' do
@@ -117,8 +115,8 @@ describe 'nova::compute::libvirt' do
       it { is_expected.to contain_nova_config('libvirt/virt_type').with_value('qemu')}
       it { is_expected.to contain_nova_config('libvirt/cpu_mode').with_value('host-passthrough')}
       it { is_expected.to contain_nova_config('libvirt/cpu_model').with_ensure('absent')}
-      it { is_expected.to contain_nova_config('libvirt/cpu_model_extra_flags').with_ensure('pcid')}
-      it { is_expected.to contain_nova_config('libvirt/snapshot_image_format').with_ensure('absent')}
+      it { is_expected.to contain_nova_config('libvirt/cpu_model_extra_flags').with_value('pcid')}
+      it { is_expected.to contain_nova_config('libvirt/snapshot_image_format').with_value('raw')}
       it { is_expected.to contain_nova_config('libvirt/disk_cachemodes').with_value('file=directsync,block=none')}
       it { is_expected.to contain_nova_config('libvirt/hw_disk_discard').with_value('unmap')}
       it { is_expected.to contain_nova_config('libvirt/hw_machine_type').with_value('x86_64=machinetype1,armv7l=machinetype2')}
@@ -134,9 +132,9 @@ describe 'nova::compute::libvirt' do
       it { is_expected.to contain_nova_config('libvirt/nfs_mount_options').with_value('rw,intr,nolock')}
       it { is_expected.to contain_nova_config('libvirt/num_pcie_ports').with_value(16)}
       it { is_expected.to contain_nova_config('libvirt/mem_stats_period_seconds').with_value(20)}
+      it { is_expected.to contain_nova_config('libvirt/pmem_namespaces').with_value("128G:ns0|ns1|ns2|ns3")}
       it { is_expected.to contain_libvirtd_config('log_filters').with_value("\"#{params[:log_filters]}\"")}
       it { is_expected.to contain_libvirtd_config('tls_priority').with_value("\"#{params[:tls_priority]}\"")}
-      it { is_expected.to contain_libvirtd_config('pmem_namespaces').with_value("128G:ns0|ns1|ns2|ns3")}
       it {
         is_expected.to contain_service('libvirt').with(
           :name     => 'custom_service',
@@ -197,10 +195,6 @@ describe 'nova::compute::libvirt' do
         it { is_expected.to contain_class('nova::migration::libvirt')}
         it { is_expected.to contain_nova_config('vnc/server_listen').with_value('0.0.0.0')}
         it { is_expected.to contain_file_line('/etc/default/libvirtd libvirtd opts').with(:line => libvirt_options) }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tls').with(:line => "listen_tls = 0") }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tcp').with(:line => "listen_tcp = 1") }
-        it { is_expected.not_to contain_file_line('/etc/libvirt/libvirtd.conf auth_tls')}
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf auth_tcp').with(:line => "auth_tcp = \"none\"") }
       end
 
       context 'with vncserver_listen set to ::0' do
@@ -212,10 +206,6 @@ describe 'nova::compute::libvirt' do
         it { is_expected.to contain_class('nova::migration::libvirt')}
         it { is_expected.to contain_nova_config('vnc/server_listen').with_value('::0')}
         it { is_expected.to contain_file_line('/etc/default/libvirtd libvirtd opts').with(:line => libvirt_options) }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tls').with(:line => "listen_tls = 0") }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tcp').with(:line => "listen_tcp = 1") }
-        it { is_expected.not_to contain_file_line('/etc/libvirt/libvirtd.conf auth_tls')}
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf auth_tcp').with(:line => "auth_tcp = \"none\"") }
       end
 
       context 'with custom libvirt service name on Debian platforms' do
@@ -278,7 +268,7 @@ describe 'nova::compute::libvirt' do
         :ensure => 'running',
         :enable => true,
         :before => ['Service[libvirt]'],
-        :name   => 'messagebus'
+        :name   => 'dbus'
       ) }
 
       describe 'on rhel 7' do
@@ -305,7 +295,7 @@ describe 'nova::compute::libvirt' do
       it { is_expected.to contain_nova_config('DEFAULT/remove_unused_base_images').with_ensure('absent')}
       it { is_expected.to contain_nova_config('DEFAULT/remove_unused_original_minimum_age_seconds').with_ensure('absent')}
       it { is_expected.to contain_nova_config('libvirt/remove_unused_resized_minimum_age_seconds').with_ensure('absent')}
-      it { is_expected.to contain_nova_config('libvirt/nfs_mount_options').with_ensure('<SERVICE DEFAULT>')}
+      it { is_expected.to contain_nova_config('libvirt/nfs_mount_options').with_value('<SERVICE DEFAULT>')}
     end
 
     describe 'with params' do
@@ -346,10 +336,6 @@ describe 'nova::compute::libvirt' do
         it { is_expected.to contain_class('nova::migration::libvirt')}
         it { is_expected.to contain_nova_config('vnc/server_listen').with_value('0.0.0.0')}
         it { is_expected.to contain_file_line('/etc/sysconfig/libvirtd libvirtd args').with(:line => 'LIBVIRTD_ARGS="--listen"') }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tls').with(:line => "listen_tls = 0") }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tcp').with(:line => "listen_tcp = 1") }
-        it { is_expected.not_to contain_file_line('/etc/libvirt/libvirtd.conf auth_tls')}
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf auth_tcp').with(:line => "auth_tcp = \"none\"") }
       end
 
       context 'with vncserver_listen set to ::0' do
@@ -361,10 +347,6 @@ describe 'nova::compute::libvirt' do
         it { is_expected.to contain_class('nova::migration::libvirt')}
         it { is_expected.to contain_nova_config('vnc/server_listen').with_value('::0')}
         it { is_expected.to contain_file_line('/etc/sysconfig/libvirtd libvirtd args').with(:line => 'LIBVIRTD_ARGS="--listen"') }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tls').with(:line => "listen_tls = 0") }
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf listen_tcp').with(:line => "listen_tcp = 1") }
-        it { is_expected.not_to contain_file_line('/etc/libvirt/libvirtd.conf auth_tls')}
-        it { is_expected.to contain_file_line('/etc/libvirt/libvirtd.conf auth_tcp').with(:line => "auth_tcp = \"none\"") }
       end
 
     end
@@ -420,31 +402,14 @@ describe 'nova::compute::libvirt' do
     :supported_os => OSDefaults.get_supported_os
   }).each do |os,facts|
     context "on #{os}" do
+      let (:facts) do
+        facts.merge!(OSDefaults.get_facts())
+      end
 
-      case [:osfamily]
+      case facts[:osfamily]
       when 'Debian'
-
-        case [:operatingsystem]
-        when 'Debian'
-          let (:facts) do
-            facts.merge!(OSDefaults.get_facts({
-              :os_package_family => 'debian',
-              :operatingsystemmajrelease => '8'}))
-          end
-          it_behaves_like 'debian-nova-compute-libvirt'
-        when 'Ubuntu'
-          let (:facts) do
-            facts.merge!(OSDefaults.get_facts({
-              :os_package_family => 'ubuntu',
-              :operatingsystemmajrelease => '16.04'}))
-          end
-          it_behaves_like 'debian-nova-compute-libvirt'
-        end
-
+        it_behaves_like 'debian-nova-compute-libvirt'
       when 'RedHat'
-        let (:facts) do
-          facts.merge!(OSDefaults.get_facts({ :os_package_type => 'rpm' }))
-        end
         it_behaves_like 'redhat-nova-compute-libvirt'
       end
     end