diff --git a/manifests/compute/mdev_type.pp b/manifests/compute/mdev_type.pp
index 22b048216..065a8cdbf 100644
--- a/manifests/compute/mdev_type.pp
+++ b/manifests/compute/mdev_type.pp
@@ -18,10 +18,15 @@
 #  device type.
 #  Defaults to $facts['os_service_default']
 #
+# [*max_instances*]
+#  (Optional) Number of mediated devices that type can create.
+#  Defaults to $facts['os_service_default']
+#
 define nova::compute::mdev_type (
   $mdev_type        = $name,
   $device_addresses = $facts['os_service_default'],
   $mdev_class       = $facts['os_service_default'],
+  $max_instances    = $facts['os_service_default'],
 ) {
 
   if empty($device_addresses) {
@@ -35,6 +40,7 @@ define nova::compute::mdev_type (
   }
 
   nova_config {
-    "mdev_${mdev_type}/mdev_class": value => $mdev_class;
+    "mdev_${mdev_type}/mdev_class":    value => $mdev_class;
+    "mdev_${mdev_type}/max_instances": value => $max_instances;
   }
 }
diff --git a/releasenotes/notes/mdev-max_instances-eeba30ae38b782b4.yaml b/releasenotes/notes/mdev-max_instances-eeba30ae38b782b4.yaml
new file mode 100644
index 000000000..531861a7e
--- /dev/null
+++ b/releasenotes/notes/mdev-max_instances-eeba30ae38b782b4.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Now the ``nova::compute::mdev_type`` defined resource type supports
+    the new ``max_instances`` parameter.
diff --git a/spec/classes/nova_compute_mdev_spec.rb b/spec/classes/nova_compute_mdev_spec.rb
index 8ac250ee2..850c8b84c 100644
--- a/spec/classes/nova_compute_mdev_spec.rb
+++ b/spec/classes/nova_compute_mdev_spec.rb
@@ -21,7 +21,8 @@ describe 'nova::compute::mdev' do
               'mdev_class'       => 'CUSTOM_MDEV1'
             },
             'nvidia-37' => {
-              'mdev_class' => 'VGPU'
+              'mdev_class'    => 'VGPU',
+              'max_instances' => 10
             }
           }
         }
@@ -31,10 +32,13 @@ describe 'nova::compute::mdev' do
         is_expected.to contain_nova_config('devices/enabled_mdev_types').with_value('nvidia-35,nvidia-36,nvidia-37')
         is_expected.to contain_nova_config('mdev_nvidia-35/device_addresses').with_value('0000:84:00.0,0000:85:00.0')
         is_expected.to contain_nova_config('mdev_nvidia-35/mdev_class').with_value('<SERVICE DEFAULT>')
+        is_expected.to contain_nova_config('mdev_nvidia-35/max_instances').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_nova_config('mdev_nvidia-36/device_addresses').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_nova_config('mdev_nvidia-36/mdev_class').with_value('CUSTOM_MDEV1')
+        is_expected.to contain_nova_config('mdev_nvidia-36/max_instances').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_nova_config('mdev_nvidia-37/device_addresses').with_value('<SERVICE DEFAULT>')
         is_expected.to contain_nova_config('mdev_nvidia-37/mdev_class').with_value('VGPU')
+        is_expected.to contain_nova_config('mdev_nvidia-37/max_instances').with_value(10)
       end
     end
   end