diff --git a/hypervisor/arch/x86/cpu.c b/hypervisor/arch/x86/cpu.c
index d995f8e06..07dc044d2 100644
--- a/hypervisor/arch/x86/cpu.c
+++ b/hypervisor/arch/x86/cpu.c
@@ -289,7 +289,7 @@ void init_pcpu_post(uint16_t pcpu_id)
 		/*
 		 * Reserve memory from platform E820 for shadow EPT 4K pages
 		 */
-		reserve_buffer_for_sept_pages();
+		allocate_buffer_for_sept_pages();
 
 		pcpu_sync = ALL_CPUS_MASK;
 		/* Start all secondary cores */
diff --git a/hypervisor/arch/x86/guest/vept.c b/hypervisor/arch/x86/guest/vept.c
index ac5f43177..26c9ae29b 100644
--- a/hypervisor/arch/x86/guest/vept.c
+++ b/hypervisor/arch/x86/guest/vept.c
@@ -26,27 +26,42 @@ static spinlock_t nept_desc_bucket_lock;
  * and sharing of memory between L2 VMs.
  *
  * Page table entry need 8 bytes to represent every 4K page frame.
- * Total number of bytes = (CONFIG_PLATFORM_RAM_SIZE/4096) * 8
- * Number of pages needed = Total number of bytes needed/4096
+ * Total number of bytes = (get_e820_ram_size() / PAGE_SIZE) * 8
+ * Number of pages needed = Total number of bytes needed/PAGE_SIZE
  */
-#define TOTAL_SEPT_4K_PAGES_SIZE	((CONFIG_PLATFORM_RAM_SIZE * 8UL) / 4096UL)
-#define TOTAL_SEPT_4K_PAGES_NUM		(TOTAL_SEPT_4K_PAGES_SIZE / PAGE_SIZE)
+static uint64_t get_total_vept_4k_page_size(void)
+{
+	return (get_e820_ram_size() * 8UL) / PAGE_SIZE;
+}
+
+static uint64_t get_total_vept_4k_page_num(void)
+{
+	return get_total_vept_4k_page_size() / PAGE_SIZE;
+}
 
 static struct page_pool sept_page_pool;
 static struct page *sept_pages;
-static uint64_t sept_page_bitmap[TOTAL_SEPT_4K_PAGES_NUM / 64U];
+static uint64_t *sept_page_bitmap;
+
+static void allocate_vept_bitmap(void)
+{
+	sept_page_bitmap = e820_alloc_memory((get_total_4k_page_num() / 64U), ~0UL);
+}
 
 /*
  * @brief Reserve space for SEPT 4K pages from platform E820 table
  * 	  At moment, we only support nested VMX for Service VM.
  */
-void reserve_buffer_for_sept_pages(void)
+void allocate_buffer_for_sept_pages(void)
 {
 	uint64_t page_base;
 
-	page_base = e820_alloc_memory(TOTAL_SEPT_4K_PAGES_SIZE, ~0UL);
-	set_paging_supervisor(page_base, TOTAL_SEPT_4K_PAGES_SIZE);
+	page_base = e820_alloc_memory(get_total_vept_4k_page_size(), ~0UL);
+
+	set_paging_supervisor(page_base, get_total_vept_4k_page_size());
+
 	sept_pages = (struct page *)page_base;
+	allocate_vept_bitmap();
 }
 
 static bool is_present_ept_entry(uint64_t ept_entry)
@@ -535,7 +550,7 @@ int32_t invept_vmexit_handler(struct acrn_vcpu *vcpu)
 void init_vept(void)
 {
 	sept_page_pool.start_page = sept_pages;
-	sept_page_pool.bitmap_size = TOTAL_SEPT_4K_PAGES_NUM / 64U;
+	sept_page_pool.bitmap_size = get_total_vept_4k_page_num() / 64U;
 	sept_page_pool.bitmap = sept_page_bitmap;
 	sept_page_pool.dummy_page = NULL;
 	spinlock_init(&sept_page_pool.lock);
diff --git a/hypervisor/include/arch/x86/asm/guest/vept.h b/hypervisor/include/arch/x86/asm/guest/vept.h
index 3d7d030e4..159a62537 100644
--- a/hypervisor/include/arch/x86/asm/guest/vept.h
+++ b/hypervisor/include/arch/x86/asm/guest/vept.h
@@ -38,7 +38,7 @@ struct nept_desc {
 	uint32_t ref_count;
 };
 
-void reserve_buffer_for_sept_pages(void);
+void allocate_buffer_for_sept_pages(void);
 void init_vept(void);
 uint64_t get_shadow_eptp(uint64_t guest_eptp);
 struct nept_desc *get_nept_desc(uint64_t guest_eptp);
@@ -46,6 +46,6 @@ void put_nept_desc(uint64_t guest_eptp);
 bool handle_l2_ept_violation(struct acrn_vcpu *vcpu);
 int32_t invept_vmexit_handler(struct acrn_vcpu *vcpu);
 #else
-static inline void reserve_buffer_for_sept_pages(void) {};
+static inline void allocate_buffer_for_sept_pages(void) {};
 #endif /* CONFIG_NVMX_ENABLED */
 #endif /* VEPT_H */