diff --git a/nova/virt/libvirt/config.py b/nova/virt/libvirt/config.py
index 2a1e703d31..936eb4052e 100644
--- a/nova/virt/libvirt/config.py
+++ b/nova/virt/libvirt/config.py
@@ -2136,6 +2136,23 @@ class LibvirtConfigGuestVideo(LibvirtConfigGuestDevice):
 
         return dev
 
+#RABSER
+class LibvirtConfigCommandLine(LibvirtConfigObject):
+    def __init__(self, **kwargs):
+        super(LibvirtConfigCommandLine, self).__init__(
+            root_name='commandline',
+            ns_uri = "http://libvirt.org/schemas/domain/qemu/1.0",
+            **kwargs)
+        self.memsize = None
+
+    def format_dom(self):
+        cmdline = super(LibvirtConfigCommandLine, self).format_dom()
+
+        cmdline.append(etree.Element('arg', value='-fw_cfg'))
+        cmdline.append(etree.Element('arg', value='opt/ovmf/X-PciMmio64Mb,string='+str(self.memsize)))
+        return cmdline
+#RABSER END
+
 
 class LibvirtConfigMemoryBalloon(LibvirtConfigGuestDevice):
     def __init__(self, **kwargs):
@@ -2945,6 +2962,9 @@ class LibvirtConfigGuest(LibvirtConfigObject):
         self.idmaps = []
         self.perf_events = []
         self.launch_security = None
+        #RABSER
+        self.cmdline = None
+        #RABSER END
 
     def _format_basic_props(self, root):
         root.append(self._text_node("uuid", self.uuid))
@@ -3041,6 +3061,12 @@ class LibvirtConfigGuest(LibvirtConfigObject):
                 features.append(feat.format_dom())
             root.append(features)
 
+    #RABSER
+    def _format_cmdline(self, root):
+        if self.cmdline is not None :
+            root.append(self.cmdline.format_dom())
+    #RABSER END
+
     def _format_devices(self, root):
         if len(self.devices) == 0:
             return
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index 863ac60af0..d6d773f80f 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -36,6 +36,9 @@ import grp
 import itertools
 import operator
 import os
+#RABSER
+import re
+#RABSER END
 import pwd
 import random
 import shutil
@@ -7131,6 +7134,30 @@ class LibvirtDriver(driver.ComputeDriver):
 
         self._guest_add_memory_balloon(guest)
 
+        #RABSER PATCH for UEFI/PCI support
+        if guest.os_loader == DEFAULT_UEFI_LOADER_PATH[caps.host.cpu.arch]:
+            memsize = 0
+            for device in guest.devices:
+                if device.root_name == 'hostdev' and device.type == 'pci':
+                    pcibasepath='/sys/bus/pci/devices/'
+                    resource_regex = re.compile('resource[0-9]+$')
+
+                    dev_dir=pcibasepath+device.domain+':'+device.bus+':'+device.slot+'.'+device.function
+                    for path in os.scandir(dev_dir):
+                       if path.is_file():
+                           if resource_regex.match(path.name):
+                              file_stats=os.stat(dev_dir+'/'+path.name)
+                              memsize += int(file_stats.st_size/1024/1024)
+            if os.path.isfile('/usr/share/OVMF/MEMFD.fd'):
+                if memsize > 0:
+                    LOG.warning("adding custom X-PciMmio64Mb argument to domain")
+                    self._guest_add_commandline(guest,memsize)
+            else:                                                                                                            
+                LOG.warning("BEWARE: your OVMF firmware seems too old and does not supports X-PciMmio64Mb argument")         
+                LOG.warning("Anyway, you can build the firmware by yourself following the instruction here: https://github.com/tianocore/edk2.g
+it and put the *.fd  files newly built in /usr/share/OVMF overwriting the old ones")
+        #RABSER END                                           
+
         if mdevs:
             self._guest_add_mdevs(guest, mdevs)
 
@@ -7276,6 +7303,14 @@ class LibvirtDriver(driver.ComputeDriver):
             channel.target_name = "com.redhat.spice.0"
             guest.add_device(channel)
 
+    #RABSER add a commandline section to domain xml for UEFI/PCI support
+    @staticmethod
+    def _guest_add_commandline(guest,memsize):
+        cmdline = vconfig.LibvirtConfigCommandLine()
+        cmdline.memsize = memsize
+        guest.cmdline = cmdline
+    #RABSER END              
+
     @staticmethod
     def _guest_add_memory_balloon(guest):
         # Memory balloon device only support 'qemu/kvm' hypervisor