diff --git a/misc/config_tools/launch_config/launch_cfg_gen.py b/misc/config_tools/launch_config/launch_cfg_gen.py
index e0ccca1c0..910b2e6df 100755
--- a/misc/config_tools/launch_config/launch_cfg_gen.py
+++ b/misc/config_tools/launch_config/launch_cfg_gen.py
@@ -55,6 +55,10 @@ class LaunchScript:
             next_vbdf = self._free_slots.pop(0)
             return next_vbdf
 
+        def remove_virtual_bdf(self, slot):
+            if slot in self._free_slots:
+                self._free_slots.remove(slot)
+
     class PassThruDeviceOptions:
         passthru_device_options = {
             "0x0200": [".//PTM[text()='y']", "enable_ptm"],  # Ethernet controller, added if PTM is enabled for the VM
@@ -165,6 +169,8 @@ class LaunchScript:
 
         if vbdf is None:
             vbdf = self._vbdf_allocator.get_virtual_bdf()
+        else:
+            self._vbdf_allocator.remove_virtual_bdf(vbdf)
         self.add_dynamic_dm_parameter("add_virtual_device", f"{vbdf} {kind} {options}")
 
     def add_passthru_device(self, bus, dev, fun, options=""):
@@ -253,6 +259,9 @@ def generate_for_one_vm(board_etree, hv_scenario_etree, vm_scenario_etree, vm_id
     # Emulated PCI devices
     script.add_virtual_device("hostbridge", vbdf="0:0")
 
+    #ivshmem and vuart must be the first virtual devices generated before the others except hostbridge and LPC
+    #ivshmem and vuart own reserved slots which setting by user
+
     for ivshmem in eval_xpath_all(vm_scenario_etree, f"//IVSHMEM_REGION[PROVIDED_BY = 'Device Model' and .//VM_NAME = '{vm_name}']"):
         script.add_virtual_device("ivshmem", options=f"dm:/{ivshmem.find('NAME').text},{ivshmem.find('IVSHMEM_SIZE').text}")
 
@@ -262,9 +271,14 @@ def generate_for_one_vm(board_etree, hv_scenario_etree, vm_scenario_etree, vm_id
     if eval_xpath(vm_scenario_etree, ".//console_vuart/text()") == "PCI":
         script.add_virtual_device("uart", options="vuart_idx:0")
 
-    for idx, conn in enumerate(eval_xpath_all(hv_scenario_etree, f".//vuart_connection[endpoint/vm_name = '{vm_name}']"), start=1):
-        if eval_xpath(conn, "./type/text()") == "pci":
-            script.add_virtual_device("uart", options=f"vuart_idx:{idx}")
+    for idx, conn in enumerate(eval_xpath_all(hv_scenario_etree, f"//vuart_connection[endpoint/vm_name/text() = '{vm_name}']"), start=1):
+        if eval_xpath(conn, f"./type/text()") == "pci":
+            vbdf = eval_xpath(conn, f"./endpoint[vm_name/text() = '{vm_name}']/vbdf/text()")
+            if vbdf is not None:
+                slot = int((vbdf.split(":")[1].split(".")[0]), 16)
+            else:
+                slot = None
+            script.add_virtual_device("uart", slot, options=f"vuart_idx:{idx}")
 
     # Mediated PCI devices, including virtio
     for usb_xhci in eval_xpath_all(vm_scenario_etree, ".//usb_xhci/usb_dev[text() != '']/text()"):
diff --git a/misc/config_tools/static_allocators/gpa.py b/misc/config_tools/static_allocators/gpa.py
index d0ac4a515..726457a36 100644
--- a/misc/config_tools/static_allocators/gpa.py
+++ b/misc/config_tools/static_allocators/gpa.py
@@ -109,15 +109,20 @@ class AddrWindow(namedtuple(
             return False
         return True
 
-def insert_vuart_to_dev_dict(scenario_etree, devdict_32bits):
+def insert_vuart_to_dev_dict(scenario_etree, vm_id, devdict_32bits):
+
     console_vuart =  scenario_etree.xpath(f"./console_vuart[base != 'INVALID_PCI_BASE']/@id")
-    communication_vuarts = scenario_etree.xpath(f".//communication_vuart[base != 'INVALID_PCI_BASE']/@id")
     for vuart_id in console_vuart:
         devdict_32bits[(f"{VUART}_{vuart_id}", "bar0")] = PCI_VUART_VBAR0_SIZE
         devdict_32bits[(f"{VUART}_{vuart_id}", "bar1")] = PCI_VUART_VBAR1_SIZE
-    for vuart_id in communication_vuarts:
-        devdict_32bits[(f"{VUART}_{vuart_id}", "bar0")] = PCI_VUART_VBAR0_SIZE
-        devdict_32bits[(f"{VUART}_{vuart_id}", "bar1")] = PCI_VUART_VBAR1_SIZE
+
+    vm_name = common.get_node(f"//vm[@id = '{vm_id}']/name/text()", scenario_etree)
+    communication_vuarts = scenario_etree.xpath(f"//vuart_connection[endpoint/vm_name/text() = '{vm_name}']")
+    for vuart_id, vuart in enumerate(communication_vuarts, start=1):
+        connection_type = common.get_node(f"./type/text()", vuart)
+        if connection_type == "pci":
+            devdict_32bits[(f"{VUART}_{vuart_id}", "bar0")] = PCI_VUART_VBAR0_SIZE
+            devdict_32bits[(f"{VUART}_{vuart_id}", "bar1")] = PCI_VUART_VBAR1_SIZE
 
 def insert_legacy_vuart_to_dev_dict(vm_node, devdict_io_port):
     legacy_vuart =  vm_node.xpath(f".//legacy_vuart[base = 'CONFIG_COM_BASE']/@id")
@@ -409,7 +414,7 @@ def allocate_pci_bar(board_etree, scenario_etree, allocation_etree):
 
         devdict_32bits = {}
         devdict_64bits = {}
-        insert_vuart_to_dev_dict(vm_node, devdict_32bits)
+        insert_vuart_to_dev_dict(scenario_etree, vm_id, devdict_32bits)
         insert_ivsheme_to_dev_dict(scenario_etree, devdict_32bits, devdict_64bits, vm_id)
         insert_pt_devs_to_dev_dict(board_etree, vm_node, devdict_32bits, devdict_64bits)
 
diff --git a/misc/config_tools/xforms/lib.xsl b/misc/config_tools/xforms/lib.xsl
index 0e28f89f1..615961a16 100644
--- a/misc/config_tools/xforms/lib.xsl
+++ b/misc/config_tools/xforms/lib.xsl
@@ -331,8 +331,13 @@
           </xsl:otherwise>
         </xsl:choose>
       </xsl:variable>
+
       <xsl:variable name="console_vuart" select="count(./console_vuart/base[text() = 'PCI_VUART'])" />
-      <xsl:variable name="communication_vuart" select="count(./communication_vuart/base[text() = 'PCI_VUART'])" />
+      <xsl:variable name="vm_name" select="./name" />
+      <xsl:variable name="communication_vuart">
+        <xsl:value-of select="count(//vuart_connection[type = 'pci']/endpoint[vm_name/text() = $vm_name])" />
+      </xsl:variable>
+
       <xsl:variable name="pci_devs" select="count(./pci_devs/pci_dev[text() != ''])" />
       <xsl:variable name="pci_hostbridge" select="1" />
       <xsl:variable name="virtual_root_port">
diff --git a/misc/config_tools/xforms/pci_dev.c.xsl b/misc/config_tools/xforms/pci_dev.c.xsl
index de654b5e1..fdc274b97 100644
--- a/misc/config_tools/xforms/pci_dev.c.xsl
+++ b/misc/config_tools/xforms/pci_dev.c.xsl
@@ -46,7 +46,7 @@
     </xsl:if>
     <xsl:call-template name="ivshmem_shm_mem" />
     <xsl:apply-templates select="console_vuart" />
-    <xsl:apply-templates select="communication_vuart" />
+    <xsl:call-template name="communication_vuart" />
     <xsl:if test="acrn:is-pre-launched-vm(load_order)">
       <xsl:apply-templates select="pci_devs" />
     </xsl:if>
@@ -95,32 +95,55 @@
     </xsl:if>
   </xsl:template>
 
-  <xsl:template match="communication_vuart">
-    <xsl:if test="base != 'INVALID_PCI_BASE'">
-      <xsl:variable name="vm_id" select="../@id" />
-      <xsl:variable name="dev_name" select="concat('VUART_', @id)" />
-      <xsl:text>{</xsl:text>
-      <xsl:value-of select="$newline" />
-      <xsl:value-of select="acrn:initializer('vuart_idx', @id, '')" />
-      <xsl:value-of select="acrn:initializer('emu_type', 'PCI_DEV_TYPE_HVEMUL', '')" />
-      <xsl:value-of select="acrn:initializer('vdev_ops', '&amp;vmcs9900_ops', '')" />
-      <xsl:choose>
-        <xsl:when test="acrn:is-post-launched-vm(../load_order)">
-          <xsl:value-of select="acrn:initializer('vbar_base[0]', 'INVALID_PCI_BASE', '')" />
-          <xsl:value-of select="acrn:initializer('vbdf.value', 'UNASSIGNED_VBDF', '')" />
-        </xsl:when>
-        <xsl:otherwise>
-          <xsl:for-each select="//vm[@id = $vm_id]/device[@name = $dev_name]/bar">
-            <xsl:value-of select="acrn:initializer(concat('vbar_base[', @id,']'), concat(text(), 'UL'), '')" />
-          </xsl:for-each>
-          <xsl:value-of select="acrn:initializer('vbdf.bits', acrn:get-vbdf(../@id, $dev_name), '')" />
-        </xsl:otherwise>
-      </xsl:choose>
-      <xsl:value-of select="acrn:initializer('t_vuart.vm_id', target_vm_id, '')" />
-      <xsl:value-of select="acrn:initializer('t_vuart.vuart_id', target_uart_id, '')" />
+  <xsl:template name="communication_vuart">
+    <xsl:variable name="vm_id" select="@id" />
+    <xsl:variable name="vm_name" select="name/text()" />
+    <xsl:variable name="load_order" select="load_order/text()" />
+    <xsl:for-each select="//vuart_connection[endpoint/vm_name/text() = $vm_name]">
+      <xsl:variable name="connection_name" select="name/text()" />
+      <xsl:if test="./type/text() = 'pci'">
+        <xsl:variable name="vuart_id" select="position()"/>
+        <xsl:variable name="dev_name" select="concat('VUART_', $vuart_id)" />
+        <xsl:text>{</xsl:text>
+        <xsl:value-of select="$newline" />
+        <xsl:value-of select="acrn:initializer('vuart_idx', $vuart_id, '')" />
+        <xsl:value-of select="acrn:initializer('emu_type', 'PCI_DEV_TYPE_HVEMUL', '')" />
+        <xsl:value-of select="acrn:initializer('vdev_ops', '&amp;vmcs9900_ops', '')" />
+        <xsl:for-each select="endpoint">
+          <xsl:choose>
+            <xsl:when test="vm_name = $vm_name">
+              <xsl:choose>
+                <xsl:when test="acrn:is-post-launched-vm($load_order)">
+                  <xsl:value-of select="acrn:initializer('vbar_base[0]', 'INVALID_PCI_BASE', '')" />
+                  <xsl:value-of select="acrn:initializer('vbdf.value', 'UNASSIGNED_VBDF')" />
+                </xsl:when>
+                <xsl:otherwise>
+                  <xsl:for-each select="//vm[@id = $vm_id]/device[@name = $dev_name]/bar">
+                    <xsl:value-of select="acrn:initializer(concat('vbar_base[', @id,']'), concat(text(), 'UL'), '')" />
+                  </xsl:for-each>
+                  <xsl:variable name="b" select="substring-before(vbdf/text(), ':')" />
+                  <xsl:variable name="d" select="substring-before(substring-after(vbdf/text(), ':'), '.')" />
+                  <xsl:variable name="f" select="substring-after(vbdf/text(), '.')" />
+                  <xsl:value-of select="acrn:initializer('vbdf.bits', concat('{', '0x', $b, ', ', '0x', $d, ', ', '0x', $f, '}'))" />
+                </xsl:otherwise>
+              </xsl:choose>
+            </xsl:when>
+            <xsl:otherwise>
+              <xsl:variable name="target_name" select="vm_name" />
+              <xsl:value-of select="acrn:initializer('t_vuart.vm_id', concat(//vm[name = $target_name]/@id, 'U'))" />
+              <xsl:for-each select="//vuart_connection[endpoint/vm_name = $target_name]">
+                <xsl:variable name="uart_num" select="position()"/>
+                <xsl:if test="name = $connection_name">
+                  <xsl:value-of select="acrn:initializer('t_vuart.vuart_id', concat($uart_num, 'U'))" />
+                </xsl:if>
+              </xsl:for-each>
+            </xsl:otherwise>
+          </xsl:choose>
+        </xsl:for-each>
       <xsl:text>},</xsl:text>
       <xsl:value-of select="$newline" />
-    </xsl:if>
+      </xsl:if>
+    </xsl:for-each>
   </xsl:template>
 
   <xsl:template match="pci_devs">
diff --git a/misc/config_tools/xforms/vm_configurations.c.xsl b/misc/config_tools/xforms/vm_configurations.c.xsl
index 2a6ea08d0..bb2c3e29d 100644
--- a/misc/config_tools/xforms/vm_configurations.c.xsl
+++ b/misc/config_tools/xforms/vm_configurations.c.xsl
@@ -296,42 +296,27 @@
       <xsl:variable name="type" select="type/text()" />
       <xsl:variable name="vuart_id" select="position()"/>
       <xsl:value-of select="acrn:initializer(concat('vuart[', $vuart_id, ']'), '{', true())" />
-      <xsl:choose>
-        <xsl:when test="$type = 'legacy'">
-          <xsl:value-of select="acrn:initializer('type', 'VUART_LEGACY_PIO')" />
-        </xsl:when>
-        <xsl:when test="$type = 'pci'">
-          <xsl:value-of select="acrn:initializer('type', 'VUART_PCI')" />
-        </xsl:when>
-      </xsl:choose>
-      <xsl:value-of select="acrn:initializer('irq', concat(//allocation-data/acrn-config/vm[@id=$vm_id]/legacy_vuart[@id=$vuart_id]/irq, 'U'))" />
-      <xsl:for-each select="endpoint">
-        <xsl:choose>
-          <xsl:when test="vm_name = $vmname">
-            <xsl:choose>
-              <xsl:when test="$type = 'legacy'">
-                <xsl:value-of select="acrn:initializer('addr.port_base', concat(io_port, 'U'))" />
-              </xsl:when>
-              <xsl:when test="$type = 'pci'">
-                <xsl:variable name="b" select="substring-before(vbdf/text(), ':')" />
-                <xsl:variable name="d" select="substring-before(substring-after(vbdf/text(), ':'), '.')" />
-                <xsl:variable name="f" select="substring-after(vbdf/text(), '.')" />
-                <xsl:value-of select="acrn:initializer('addr.bdf', concat('{', $b, ', ', $d, ', ', $f, '}'))" />
-              </xsl:when>
-            </xsl:choose>
-          </xsl:when>
-          <xsl:otherwise>
-            <xsl:variable name="target_name" select="vm_name" />
-            <xsl:value-of select="acrn:initializer('t_vuart.vm_id', concat(//vm[name = $target_name]/@id, 'U'))" />
-            <xsl:for-each select="//vuart_connection[endpoint/vm_name = $target_name]">
-              <xsl:variable name="uart_num" select="position()"/>
-              <xsl:if test="name = $connection_name">
-	        <xsl:value-of select="acrn:initializer('t_vuart.vuart_id', concat($uart_num, 'U'))" />
-              </xsl:if>
-          </xsl:for-each>
-          </xsl:otherwise>
-        </xsl:choose>
-      </xsl:for-each>
+      <xsl:if test="$type = 'legacy'">
+        <xsl:value-of select="acrn:initializer('irq', concat(//allocation-data/acrn-config/vm[@id=$vm_id]/legacy_vuart[@id=$vuart_id]/irq, 'U'))" />
+        <xsl:value-of select="acrn:initializer('type', 'VUART_LEGACY_PIO')" />
+        <xsl:for-each select="endpoint">
+          <xsl:choose>
+            <xsl:when test="vm_name = $vmname">
+              <xsl:value-of select="acrn:initializer('addr.port_base', concat(io_port, 'U'))" />
+            </xsl:when>
+            <xsl:otherwise>
+              <xsl:variable name="target_name" select="vm_name" />
+              <xsl:value-of select="acrn:initializer('t_vuart.vm_id', concat(//vm[name = $target_name]/@id, 'U'))" />
+              <xsl:for-each select="//vuart_connection[endpoint/vm_name = $target_name]">
+                <xsl:variable name="uart_num" select="position()"/>
+                <xsl:if test="name = $connection_name">
+                  <xsl:value-of select="acrn:initializer('t_vuart.vuart_id', concat($uart_num, 'U'))" />
+                </xsl:if>
+              </xsl:for-each>
+            </xsl:otherwise>
+          </xsl:choose>
+        </xsl:for-each>
+      </xsl:if>
       <xsl:text>},</xsl:text>
       <xsl:value-of select="$newline" />
     </xsl:for-each>