diff --git a/misc/config_tools/static_allocators/board_capability.py b/misc/config_tools/static_allocators/board_capability.py
new file mode 100644
index 000000000..5a98f472d
--- /dev/null
+++ b/misc/config_tools/static_allocators/board_capability.py
@@ -0,0 +1,12 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2021 Intel Corporation.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+import common
+
+def fn(board_etree, scenario_etree, allocation_etree):
+    pci_bus_nums =  board_etree.xpath("//bus[@type='pci']/@address")
+    common.append_node("/acrn-config/platform/MAX_PCI_BUS_NUM", hex(max(map(lambda x: int(x, 16), pci_bus_nums)) + 1), allocation_etree)
diff --git a/misc/config_tools/xforms/config.h.xsl b/misc/config_tools/xforms/config.h.xsl
index e4cd0cca5..bab5d7cc4 100644
--- a/misc/config_tools/xforms/config.h.xsl
+++ b/misc/config_tools/xforms/config.h.xsl
@@ -26,11 +26,20 @@
   </xsl:template>
 
   <xsl:template name="entry-by-key-value">
+    <xsl:param name="prefix" />
     <xsl:param name="key" />
     <xsl:param name="value" />
     <xsl:param name="default" />
 
-    <xsl:text>#define CONFIG_</xsl:text>
+    <xsl:text>#define </xsl:text>
+    <xsl:choose>
+      <xsl:when test="$prefix != ''">
+        <xsl:value-of select="$prefix" />
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:text>CONFIG_</xsl:text>
+      </xsl:otherwise>
+    </xsl:choose>
     <xsl:value-of select="$key" />
     <xsl:text> </xsl:text>
     <xsl:choose>
diff --git a/misc/config_tools/xforms/config.mk.xsl b/misc/config_tools/xforms/config.mk.xsl
index 6ebf6e80c..3620ce9aa 100644
--- a/misc/config_tools/xforms/config.mk.xsl
+++ b/misc/config_tools/xforms/config.mk.xsl
@@ -21,11 +21,19 @@
   </xsl:template>
 
   <xsl:template name="entry-by-key-value">
+    <xsl:param name="prefix" />
     <xsl:param name="key" />
     <xsl:param name="value" />
     <xsl:param name="default" />
 
-    <xsl:text>CONFIG_</xsl:text>
+    <xsl:choose>
+      <xsl:when test="$prefix != ''">
+        <xsl:value-of select="$prefix" />
+      </xsl:when>
+      <xsl:otherwise>
+        <xsl:text>CONFIG_</xsl:text>
+      </xsl:otherwise>
+    </xsl:choose>
     <xsl:value-of select="$key" />
     <xsl:text>=</xsl:text>
     <xsl:choose>
diff --git a/misc/config_tools/xforms/config_common.xsl b/misc/config_tools/xforms/config_common.xsl
index 22fe7d88b..700b202d3 100644
--- a/misc/config_tools/xforms/config_common.xsl
+++ b/misc/config_tools/xforms/config_common.xsl
@@ -151,8 +151,10 @@
   </xsl:template>
 
   <xsl:template match="CAPACITIES">
-    <xsl:call-template name="integer-by-key">
-      <xsl:with-param name="key" select="'IOMMU_BUS_NUM'" />
+    <xsl:call-template name="integer-by-key-value">
+      <xsl:with-param name="prefix" select="'ACFG_'" />
+      <xsl:with-param name="key" select="'MAX_PCI_BUS_NUM'" />
+      <xsl:with-param name="value" select="//allocation-data/acrn-config/platform/MAX_PCI_BUS_NUM" />
     </xsl:call-template>
 
     <xsl:call-template name="integer-by-key">
@@ -314,6 +316,7 @@
   <!-- Common library routines -->
 
   <xsl:template name="integer-by-key-value">
+    <xsl:param name="prefix" />
     <xsl:param name="key" />
     <xsl:param name="value" />
     <xsl:param name="default" />
@@ -321,18 +324,21 @@
     <xsl:choose>
       <xsl:when test="$value != ''">
 	<xsl:call-template name="entry-by-key-value">
+	  <xsl:with-param name="prefix" select="$prefix" />
 	  <xsl:with-param name="key" select="$key" />
 	  <xsl:with-param name="value" select="concat($value, $integer-suffix)" />
 	</xsl:call-template>
       </xsl:when>
       <xsl:when test="($value = '') and ($default != '')">
 	<xsl:call-template name="entry-by-key-value">
+	  <xsl:with-param name="prefix" select="$prefix" />
 	  <xsl:with-param name="key" select="$key" />
 	  <xsl:with-param name="value" select="concat($default, $integer-suffix)" />
 	</xsl:call-template>
       </xsl:when>
       <xsl:otherwise>
 	<xsl:call-template name="entry-by-key-value">
+	  <xsl:with-param name="prefix" select="$prefix" />
 	  <xsl:with-param name="key" select="$key" />
 	</xsl:call-template>
       </xsl:otherwise>