diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 82577eec6d0a..f9b31eb6846c 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -613,8 +613,8 @@ int xen_alloc_p2m_entry(unsigned long pfn)
 	}
 
 	/* Expanded the p2m? */
-	if (pfn > xen_p2m_last_pfn) {
-		xen_p2m_last_pfn = pfn;
+	if (pfn >= xen_p2m_last_pfn) {
+		xen_p2m_last_pfn = ALIGN(pfn + 1, P2M_PER_PAGE);
 		HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;
 	}