diff --git a/docker/services/nova-libvirt.yaml b/docker/services/nova-libvirt.yaml
index 0553e1cfe4..76b7fd89c1 100644
--- a/docker/services/nova-libvirt.yaml
+++ b/docker/services/nova-libvirt.yaml
@@ -125,6 +125,14 @@ parameters:
     type: string
     tags:
       - role_specific
+  QemuMemoryBackingDir:
+    type: string
+    description: >
+      Directory used for memoryBacking source if configured as file.
+      NOTE: big files will be stored here
+    default: ''
+    tags:
+      - role_specific
 
 conditions:
 
@@ -165,6 +173,11 @@ conditions:
       - {get_param: LibvirtVncCACert}
       - ''
 
+  memory_backing_dir_set:
+    not:
+      equals:
+      - {get_param: QemuMemoryBackingDir}
+      - ''
 
 resources:
   RoleParametersValue:
@@ -175,9 +188,11 @@ resources:
         map_replace:
           - map_replace:
             - vhostuser_socket_group: VhostuserSocketGroup
+              memory_backing_dir: QemuMemoryBackingDir
             - values: {get_param: [RoleParameters]}
           - values:
               VhostuserSocketGroup: {get_param: VhostuserSocketGroup}
+              QemuMemoryBackingDir: {get_param: QemuMemoryBackingDir}
 
 
   ContainersCommon:
@@ -362,6 +377,15 @@ outputs:
                                 - get_param: LibvirtVncCACert
                       - /etc/pki/libvirt-vnc:/var/lib/kolla/config_files/src-libvirt-vnc-pki:ro
                     - null
+                -
+                  if:
+                    - memory_backing_dir_set
+                    -
+                      - str_replace:
+                          template: "MEMORY_BACKING_DIR:MEMORY_BACKING_DIR"
+                          params:
+                            MEMORY_BACKING_DIR: {get_attr: [RoleParametersValue, value, memory_backing_dir]}
+                    - null
             environment:
               - KOLLA_CONFIG_STRATEGY=COPY_ALWAYS
         step_4:
diff --git a/puppet/services/nova-compute.yaml b/puppet/services/nova-compute.yaml
index e91f668d12..5f1abe02c6 100644
--- a/puppet/services/nova-compute.yaml
+++ b/puppet/services/nova-compute.yaml
@@ -189,6 +189,13 @@ parameters:
       - allowed_values: [ 256, 512, 1024 ]
     tags:
       - role_specific
+  NovaLibvirtFileBackedMemory:
+    description: >
+      Available capacity in MiB for file-backed memory.
+    default: 0
+    type: number
+    tags:
+      - role_specific
 
 conditions:
   enable_live_migration_tunnelled:
@@ -196,6 +203,12 @@ conditions:
       - equals: [{get_param: NovaNfsEnabled}, true]
       - equals: [{get_param: NovaEnableRbdBackend}, true]
 
+  libvirt_file_backed_memory_enabled:
+    not:
+      or:
+      -  equals: [{get_param: NovaLibvirtFileBackedMemory}, '']
+      -  equals: [{get_param: NovaLibvirtFileBackedMemory}, 0]
+
 resources:
   NovaBase:
     type: ./nova-base.yaml
@@ -224,6 +237,7 @@ resources:
               nova::compute::resume_guests_state_on_host_boot: NovaResumeGuestsStateOnHostBoot
               nova::compute::libvirt::rx_queue_size: NovaLibvirtRxQueueSize
               nova::compute::libvirt::tx_queue_size: NovaLibvirtTxQueueSize
+              nova::compute::libvirt::file_backed_memory: NovaLibvirtFileBackedMemory
             - values: {get_param: [RoleParameters]}
           - values:
               NovaVcpuPinSet: {get_param: NovaVcpuPinSet}
@@ -234,6 +248,7 @@ resources:
               NovaResumeGuestsStateOnHostBoot: {get_param: NovaResumeGuestsStateOnHostBoot}
               NovaLibvirtRxQueueSize: {get_param: NovaLibvirtRxQueueSize}
               NovaLibvirtTxQueueSize: {get_param: NovaLibvirtTxQueueSize}
+              NovaLibvirtFileBackedMemory: {get_param: NovaLibvirtFileBackedMemory}
 
 outputs:
   role_data:
@@ -313,6 +328,12 @@ outputs:
             nova::vncproxy::common::vncproxy_host: {get_param: [EndpointMap, NovaVNCProxyPublic, host_nobrackets]}
             nova::vncproxy::common::vncproxy_port: {get_param: [EndpointMap, NovaVNCProxyPublic, port]}
             nova::compute::verify_glance_signatures: {get_param: [VerifyGlanceSignatures]}
+            # if libvirt_file_backed_memory_enabled we have to set ram_allocation_ratio to 1.0
+            nova::ram_allocation_ratio:
+              if:
+              - libvirt_file_backed_memory_enabled
+              - '1.0'
+              - null
       step_config: |
         # TODO(emilien): figure how to deal with libvirt profile.
         # We'll probably treat it like we do with Neutron plugins.
diff --git a/puppet/services/nova-libvirt.yaml b/puppet/services/nova-libvirt.yaml
index 45f3bac60a..924e8c3303 100644
--- a/puppet/services/nova-libvirt.yaml
+++ b/puppet/services/nova-libvirt.yaml
@@ -130,6 +130,14 @@ parameters:
     description: The password for the libvirt service when TLS is enabled
     type: string
     hidden: true
+  QemuMemoryBackingDir:
+    type: string
+    description: >
+      Directory used for memoryBacking source if configured as file.
+      NOTE: big files will be stored here
+    default: ''
+    tags:
+      - role_specific
 
 conditions:
 
@@ -173,6 +181,20 @@ resources:
       RoleName: {get_param: RoleName}
       RoleParameters: {get_param: RoleParameters}
 
+  # Merging role-specific parameters (RoleParameters) with the default parameters.
+  # RoleParameters will have the precedence over the default parameters.
+  RoleParametersValue:
+    type: OS::Heat::Value
+    properties:
+      type: json
+      value:
+        map_replace:
+          - map_replace:
+            - nova::compute::libvirt::qemu::memory_backing_dir: QemuMemoryBackingDir
+            - values: {get_param: [RoleParameters]}
+          - values:
+              QemuMemoryBackingDir: {get_param: QemuMemoryBackingDir}
+
 outputs:
   role_data:
     description: Role data for the Libvirt service.
@@ -182,6 +204,7 @@ outputs:
       config_settings:
         map_merge:
           - get_attr: [NovaBase, role_data, config_settings]
+          - get_attr: [RoleParametersValue, value]
           # we include ::nova::compute::libvirt::services in nova/libvirt profile
           - nova::compute::libvirt::manage_libvirt_services: false
           # we manage migration in nova common puppet profile
diff --git a/releasenotes/notes/nova_file_backed_memory_and_memory_backing_dir_support_for_qemu-accfda4919b3d9dd.yaml b/releasenotes/notes/nova_file_backed_memory_and_memory_backing_dir_support_for_qemu-accfda4919b3d9dd.yaml
new file mode 100644
index 0000000000..e2dd468534
--- /dev/null
+++ b/releasenotes/notes/nova_file_backed_memory_and_memory_backing_dir_support_for_qemu-accfda4919b3d9dd.yaml
@@ -0,0 +1,18 @@
+---
+features:
+  - |
+    Add nova file_backed_memory and memory_backing_dir support for qemu.conf
+
+    The libvirt driver now allows utilizing file backed memory for qemu/KVM
+    virtual machines, via a new configuration attribute
+    ``[libvirt]/file_backed_memory``, defaulting to 0 (disabled).
+
+    ``[libvirt]/file_backed_memory`` specifies the available capacity in MiB
+    for file backed memory, at the directory configured for
+    ``memory_backing_dir`` in libvirt's ``qemu.conf``. When enabled, the
+    libvirt driver will report the configured value for the total memory
+    capacity of the node, and will report used memory as the sum of all
+    configured guest memory.
+
+    Running Nova with file_backed_memory requires libvirt version 4.0.0 and
+    qemu version 2.6.0