diff --git a/misc/config_tools/static_allocators/intx.py b/misc/config_tools/static_allocators/intx.py
index f113d63d6..50b7c5daf 100644
--- a/misc/config_tools/static_allocators/intx.py
+++ b/misc/config_tools/static_allocators/intx.py
@@ -8,6 +8,9 @@
 import sys, os
 sys.path.append(os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'library'))
 import common, board_cfg_lib, lib.error, lib.lib
+import re
+from collections import defaultdict
+from itertools import combinations
 
 LEGACY_IRQ_MAX = 16
 
@@ -47,7 +50,7 @@ def create_vuart_irq_node(etree, vm_id, vuart_id, irq):
 
     common.append_node(f"./legacy_vuart[@id = '{vuart_id}']/irq", irq, allocation_sos_vm_node)
 
-def fn(board_etree, scenario_etree, allocation_etree):
+def alloc_sos_vuart_irqs(board_etree, scenario_etree, allocation_etree):
     irq_list = get_native_valid_irq()
     hv_debug_console = lib.lib.parse_hv_console(scenario_etree)
     native_ttys = lib.lib.get_native_ttys()
@@ -69,3 +72,133 @@ def fn(board_etree, scenario_etree, allocation_etree):
             vuart1_irq = alloc_irq(irq_list)
 
             create_vuart_irq_node(allocation_etree, vm_id, "1", vuart1_irq)
+
+def get_irqs_of_device(device_node):
+    irqs = set()
+
+    # IRQs in ACPI
+    for res in device_node.xpath("resource[@type='irq']"):
+        irqs.update(set(map(int, res.get("int").split(", "))))
+
+    # PCI interrupt pin
+    for res in device_node.xpath("resource[@type='interrupt_pin']"):
+        irq = res.get("source", None)
+        if irq is not None:
+            irqs.add(int(irq))
+
+    return irqs
+
+def alloc_device_irqs(board_etree, scenario_etree, allocation_etree):
+    service_vm_id = -1
+    irq_allocation = defaultdict(lambda: defaultdict(lambda: []))  # vm_id -> irq -> [device]
+
+    # Collect the list of devices that have to use INTx, excluding legacy UART which is to be emulated.
+    device_nodes = set(board_etree.xpath("//device[count(resource[@type='irq' or @type='interrupt_pin']) > 0 and count(capability[@id='MSI' or @id='MSI-X']) = 0]"))
+    uart_nodes = set(board_etree.xpath("//device[@id='PNP0501']"))
+    device_nodes -= uart_nodes
+
+    #
+    # Identify the interrupt lines each pre-launched VM uses
+    #
+    for vm in scenario_etree.xpath("//vm"):
+        vm_type = vm.find("vm_type").text
+        vm_id = int(vm.get("id"))
+        if lib.lib.is_pre_launched_vm(vm_type):
+            pt_intx_node = common.get_node("pt_intx", vm)
+            if pt_intx_node is not None:
+                pt_intx_mapping = dict(eval(f"[{pt_intx_node.text.replace(')(', '), (')}]"))
+                for irq in pt_intx_mapping.keys():
+                    irq_allocation[vm_id][irq].append("(Explicitly assigned in scenario configuration)")
+            for pci_dev in vm.xpath("pci_devs/pci_dev/text()"):
+                bdf = lib.lib.BusDevFunc.from_str(pci_dev.split(" ")[0])
+                address = hex((bdf.dev << 16) | (bdf.func))
+                device_node = common.get_node(f"//bus[@address='{hex(bdf.bus)}']/device[@address='{address}']", board_etree)
+                if device_node in device_nodes:
+                    irqs = get_irqs_of_device(device_node)
+                    for irq in irqs:
+                        irq_allocation[vm_id][irq].append(pci_dev)
+                    device_nodes.discard(device_node)
+
+            # Raise error when any pre-launched VM with LAPIC passthrough requires any interrupt line.
+            lapic_passthru_flag = common.get_node("guest_flags[guest_flag='GUEST_FLAG_LAPIC_PASSTHROUGH']", vm)
+            if lapic_passthru_flag is not None and irq_allocation[vm_id]:
+                for irq, devices in irq_allocation[vm_id].items():
+                    print(f"Interrupt line {irq} is used by the following device(s).")
+                    for device in devices:
+                        print(f"\t{device}")
+                raise lib.error.ResourceError(f"Pre-launched VM {vm_id} with LAPIC_PASSTHROUGH flag cannot use interrupt lines.")
+        elif lib.lib.is_sos_vm(vm_type):
+            service_vm_id = vm_id
+
+    #
+    # Detect interrupt line conflicts
+    #
+    conflicts = defaultdict(lambda: defaultdict(lambda: set())) # irq -> vm_id -> devices
+
+    # If a service VM exists, collect its interrupt lines as well
+    if service_vm_id >= 0:
+        # Collect the interrupt lines that may be used by the service VM
+        for device_node in device_nodes:
+            acpi_object = device_node.find("acpi_object")
+            description = ""
+            if acpi_object is not None:
+                description = acpi_object.text
+            description = device_node.get("description", description)
+
+            # Guess BDF of the device
+            bus = device_node.getparent()
+            if bus.tag == "bus" and bus.get("type") == "pci" and device_node.get("address") is not None:
+                bus_number = int(bus.get("address"), 16)
+                address = int(device_node.get("address"), 16)
+                device_number = address >> 16
+                function_number = address & 0xffff
+                description = f"{bus_number:02x}:{device_number:02x}.{function_number} {description}"
+
+                for irq in get_irqs_of_device(device_node):
+                    irq_allocation[service_vm_id][irq].append(description)
+
+    # Identify and report conflicts among interrupt lines of the VMs
+    for vm1, vm2 in combinations(irq_allocation.keys(), 2):
+        common_irqs = set(irq_allocation[vm1].keys()) & set(irq_allocation[vm2].keys())
+        for irq in common_irqs:
+            conflicts[irq][vm1].update(set(irq_allocation[vm1][irq]))
+            conflicts[irq][vm2].update(set(irq_allocation[vm2][irq]))
+
+    if conflicts:
+        print("Interrupt line conflicts detected!")
+        for irq, vm_devices in sorted(conflicts.items()):
+            print(f"Interrupt line {irq} is shared by the following devices.")
+            for vm_id, devices in vm_devices.items():
+                for device in sorted(devices):
+                    print(f"\tVM {vm_id}: {device}")
+        raise lib.error.ResourceError(f"VMs have conflicting interrupt lines.")
+
+    #
+    # Dump allocations to allocation_etree. The virtual interrupt line is the same as the physical one unless otherwise
+    # stated in the scenario configuration.
+    #
+    for vm_id, alloc in irq_allocation.items():
+        vm_node = common.get_node(f"/acrn-config/vm[@id = '{vm_id}']", allocation_etree)
+        if vm_node is None:
+            vm_node = common.append_node("/acrn-config/vm", None, allocation_etree, id = str(vm_id))
+        pt_intx_node = common.get_node(f"//vm[@id='{vm_id}']/pt_intx", scenario_etree)
+        pt_intx_mapping = dict(eval(f"[{pt_intx_node.text.replace(')(', '), (')}]")) if pt_intx_node is not None else {}
+        for irq, devs in alloc.items():
+            for dev in devs:
+                if dev.startswith("("):  # Allocation in the scenario configuration need not go to allocation.xml
+                    continue
+                bdf = dev.split(" ")[0]
+                dev_name = f"PTDEV_{bdf}"
+                dev_node = common.get_node(f"device[@name = '{dev_name}']", vm_node)
+                if dev_node is None:
+                    dev_node = common.append_node("./device", None, vm_node, name = dev_name)
+                pt_intx_node = common.get_node(f"pt_intx", dev_node)
+                virq = pt_intx_mapping.get(irq, irq)
+                if pt_intx_node is None:
+                    common.append_node(f"./pt_intx", f"({irq}, {virq})", dev_node)
+                else:
+                    pt_intx_node.text += f" ({irq}, {virq})"
+
+def fn(board_etree, scenario_etree, allocation_etree):
+    alloc_sos_vuart_irqs(board_etree, scenario_etree, allocation_etree)
+    alloc_device_irqs(board_etree, scenario_etree, allocation_etree)
diff --git a/misc/config_tools/xforms/lib.xsl b/misc/config_tools/xforms/lib.xsl
index 4873fe86e..ce51b9ef2 100644
--- a/misc/config_tools/xforms/lib.xsl
+++ b/misc/config_tools/xforms/lib.xsl
@@ -9,6 +9,8 @@
     xmlns:dyn="http://exslt.org/dynamic"
     xmlns:math="http://exslt.org/math"
     xmlns:func="http://exslt.org/functions"
+    xmlns:str="http://exslt.org/strings"
+    xmlns:set="http://exslt.org/sets"
     xmlns:acrn="http://projectacrn.org"
     extension-element-prefixes="func">
 
@@ -586,6 +588,13 @@
     </xsl:choose>
   </func:function>
 
+  <func:function name="acrn:get-intx-mapping">
+    <xsl:param name="pt_intx_nodes" />
+    <xsl:variable name="joined" select="translate(acrn:string-join($pt_intx_nodes/text(), '', '', ''), ' ', '')" />
+    <xsl:variable name="unique_mapping" select="set:distinct(str:split(str:replace($joined, ')(', ').('), '.'))" />
+    <func:result select="$unique_mapping" />
+  </func:function>
+
   <func:function name="acrn:get-vbdf">
     <xsl:param name="vmid" />
     <xsl:param name="name" />
diff --git a/misc/config_tools/xforms/misc_cfg.h.xsl b/misc/config_tools/xforms/misc_cfg.h.xsl
index bd2a384b7..62756739e 100644
--- a/misc/config_tools/xforms/misc_cfg.h.xsl
+++ b/misc/config_tools/xforms/misc_cfg.h.xsl
@@ -39,7 +39,6 @@
     <xsl:call-template name="vm0_passthrough_tpm" />
     <xsl:call-template name="vm_config_pci_dev_num" />
     <xsl:call-template name="vm_boot_args" />
-    <xsl:call-template name="vm_pt_intx_num" />
   </xsl:template>
 
   <xsl:template match="allocation-data//ssram">
@@ -216,17 +215,4 @@
   </xsl:for-each>
 </xsl:template>
 
-<xsl:template name="vm_pt_intx_num">
-  <xsl:variable name="pt_intx" select="normalize-space(vm/pt_intx)" />
-  <xsl:variable name="length" select="string-length($pt_intx) - string-length(translate($pt_intx, ',', ''))" />
-  <xsl:choose>
-    <xsl:when test="$length">
-      <xsl:value-of select="acrn:define('VM0_PT_INTX_NUM', $length, 'U')" />
-    </xsl:when>
-    <xsl:otherwise>
-      <xsl:value-of select="acrn:define('VM0_PT_INTX_NUM', 0, 'U')" />
-    </xsl:otherwise>
-  </xsl:choose>
-</xsl:template>
-
 </xsl:stylesheet>
diff --git a/misc/config_tools/xforms/pt_intx.c.xsl b/misc/config_tools/xforms/pt_intx.c.xsl
index 3a42e611d..5afad4945 100644
--- a/misc/config_tools/xforms/pt_intx.c.xsl
+++ b/misc/config_tools/xforms/pt_intx.c.xsl
@@ -20,20 +20,7 @@
     <!-- Included headers -->
     <xsl:value-of select="acrn:include('asm/vm_config.h')" />
 
-    <xsl:apply-templates select="config-data/acrn-config" />
-  </xsl:template>
-
-  <xsl:template match="config-data/acrn-config">
-    <xsl:choose>
-      <xsl:when test="(vm/pt_intx) and (normalize-space(vm/pt_intx) != '')">
-        <xsl:value-of select="$newline" />
-        <xsl:apply-templates select="vm/pt_intx" />
-      </xsl:when>
-      <xsl:otherwise>
-        <xsl:text>struct pt_intx_config vm0_pt_intx[1U];</xsl:text>
-        <xsl:value-of select="$newline" />
-      </xsl:otherwise>
-    </xsl:choose>
+    <xsl:apply-templates select="config-data/acrn-config/vm" />
   </xsl:template>
 
   <xsl:template name="format_remappings">
@@ -51,26 +38,33 @@
       <xsl:value-of select="acrn:initializer('virt_gsi', concat($virt_gsi, 'U'))" />
       <xsl:text>},</xsl:text>
       <xsl:value-of select="$newline" />
-      <xsl:call-template name="format_remappings">
-        <xsl:with-param name="pText" select="substring-after($pText, ')')" />
-        <xsl:with-param name="index" select="$index + 1" />
-      </xsl:call-template>
     </xsl:if>
   </xsl:template>
 
-  <xsl:template match="vm/pt_intx">
-    <xsl:variable name="length" select="string-length(current()) - string-length(translate(current(), ',', ''))" />
-    <xsl:if test="$length">
-      <xsl:value-of select="acrn:array-initializer('struct pt_intx_config', 'vm0_pt_intx', concat($length, 'U'))" />
-      <xsl:variable name="pText" select="normalize-space(current())" />
-      <xsl:variable name="index" select="'0'" />
-      <xsl:call-template name="format_remappings">
-        <xsl:with-param name="pText" select="$pText" />
-        <xsl:with-param name="index" select="$index" />
-      </xsl:call-template>
-      <xsl:value-of select="$end_of_array_initializer" />
+  <xsl:template match="config-data/acrn-config/vm">
+    <xsl:if test="acrn:is-pre-launched-vm(vm_type)">
+      <xsl:variable name="vm_id" select="@id" />
+      <xsl:variable name="pt_intx" select="acrn:get-intx-mapping(//vm[@id=$vm_id]//pt_intx)" />
+      <xsl:variable name="length" select="count($pt_intx)" />
+
+      <xsl:choose>
+	<xsl:when test="$length">
+	  <xsl:value-of select="acrn:array-initializer('struct pt_intx_config', concat('vm', @id, '_pt_intx'), concat($length, 'U'))" />
+	  <xsl:for-each select="$pt_intx">
+	    <xsl:call-template name="format_remappings">
+              <xsl:with-param name="pText" select="." />
+              <xsl:with-param name="index" select="position() - 1" />
+	    </xsl:call-template>
+	  </xsl:for-each>
+	  <xsl:value-of select="$end_of_array_initializer" />
+	</xsl:when>
+	<xsl:otherwise>
+	  <xsl:value-of select="acrn:array-initializer('struct pt_intx_config', concat('vm', @id, '_pt_intx'), '1U')" />
+	  <xsl:value-of select="$end_of_array_initializer" />
+	</xsl:otherwise>
+      </xsl:choose>
+      <xsl:value-of select="$newline" />
     </xsl:if>
-    <xsl:value-of select="$newline" />
   </xsl:template>
 
 </xsl:stylesheet>
diff --git a/misc/config_tools/xforms/vm_configurations.c.xsl b/misc/config_tools/xforms/vm_configurations.c.xsl
index 5554b1ec0..45cdd1c69 100644
--- a/misc/config_tools/xforms/vm_configurations.c.xsl
+++ b/misc/config_tools/xforms/vm_configurations.c.xsl
@@ -32,19 +32,21 @@
           <xsl:value-of select="acrn:extern('struct acrn_vm_pci_dev_config', concat('vm', @id, '_pci_devs'), concat('VM', @id, '_CONFIG_PCI_DEV_NUM'))" />
         </xsl:when>
       </xsl:choose>
-    </xsl:for-each>
 
-    <!-- Declaration of pt_intx -->
-    <xsl:variable name="pt_intx" select="normalize-space(vm[@id = 0]/pt_intx)" />
-    <xsl:variable name="length" select="string-length($pt_intx) - string-length(translate($pt_intx, ',', ''))" />
-    <xsl:choose>
-      <xsl:when test="$length > 0">
-        <xsl:value-of select="acrn:extern('struct pt_intx_config', 'vm0_pt_intx', concat($length, 'U'))" />
-      </xsl:when>
-      <xsl:otherwise>
-        <xsl:value-of select="acrn:extern('struct pt_intx_config', 'vm0_pt_intx', '1U')" />
-      </xsl:otherwise>
-    </xsl:choose>
+      <!-- Declaration of pt_intx -->
+      <xsl:if test="acrn:is-pre-launched-vm(vm_type)">
+	<xsl:variable name="vm_id" select="@id" />
+	<xsl:variable name="length" select="count(acrn:get-intx-mapping(//vm[@id=$vm_id]//pt_intx))" />
+	<xsl:choose>
+	  <xsl:when test="$length">
+            <xsl:value-of select="acrn:extern('struct pt_intx_config', concat('vm', @id, '_pt_intx'), concat($length, 'U'))" />
+	  </xsl:when>
+	  <xsl:otherwise>
+            <xsl:value-of select="acrn:extern('struct pt_intx_config', concat('vm', @id, '_pt_intx'), '1U')" />
+	  </xsl:otherwise>
+	</xsl:choose>
+      </xsl:if>
+    </xsl:for-each>
 
     <!-- Definition of vm_configs -->
     <xsl:value-of select="acrn:array-initializer('struct acrn_vm_config', 'vm_configs', 'CONFIG_MAX_VM_NUM')" />
@@ -253,9 +255,12 @@
       <xsl:text>},</xsl:text>
       <xsl:value-of select="$newline" />
       <xsl:value-of select="$endif" />
-      <xsl:value-of select="acrn:initializer('pt_intx_num', 'VM0_PT_INTX_NUM')" />
-      <xsl:value-of select="acrn:initializer('pt_intx', '&amp;vm0_pt_intx[0U]')" />
     </xsl:if>
+
+    <xsl:variable name="vm_id" select="@id" />
+    <xsl:variable name="length" select="count(acrn:get-intx-mapping(//vm[@id=$vm_id]//pt_intx))" />
+    <xsl:value-of select="acrn:initializer('pt_intx_num', $length)" />
+    <xsl:value-of select="acrn:initializer('pt_intx', concat('vm', @id, '_pt_intx'))" />
   </xsl:template>
 
 </xsl:stylesheet>