diff --git a/hypervisor/arch/x86/configs/vm_config.c b/hypervisor/arch/x86/configs/vm_config.c
index 1f63ef449..37c75e4fc 100644
--- a/hypervisor/arch/x86/configs/vm_config.c
+++ b/hypervisor/arch/x86/configs/vm_config.c
@@ -121,29 +121,23 @@ bool sanitize_vm_config(void)
 {
 	bool ret = true;
 	uint16_t vm_id, vuart_idx;
-	uint64_t pre_launch_pcpu_bitmap = 0UL;
 	struct acrn_vm_config *vm_config;
 
-	/* All physical CPUs except ocuppied by Pre-launched VMs are all
-	 * belong to SOS_VM. i.e. The cpu_affinity of a SOS_VM is decided
-	 * by cpu_affinity status in PRE_LAUNCHED_VMs.
-	 * We need to setup a rule, that the vm_configs[] array should follow
+	/* We need to setup a rule, that the vm_configs[] array should follow
 	 * the order of PRE_LAUNCHED_VM first, and then SOS_VM.
 	 */
 	for (vm_id = 0U; vm_id < CONFIG_MAX_VM_NUM; vm_id++) {
 		vm_config = get_vm_config(vm_id);
 
-		if ((vm_config->cpu_affinity & ~ALL_CPUS_MASK) != 0UL) {
+		if ((vm_config->cpu_affinity == 0UL) || ((vm_config->cpu_affinity & ~ALL_CPUS_MASK) != 0UL)) {
 			pr_err("%s: vm%u assigns invalid PCPU (0x%llx)", __func__, vm_id, vm_config->cpu_affinity);
 			ret = false;
 		}
 
 		switch (vm_config->load_order) {
 		case PRE_LAUNCHED_VM:
-			if (vm_config->cpu_affinity == 0UL) {
-				ret = false;
 			/* GUEST_FLAG_RT must be set if we have GUEST_FLAG_LAPIC_PASSTHROUGH set in guest_flags */
-			} else if (((vm_config->guest_flags & GUEST_FLAG_LAPIC_PASSTHROUGH) != 0U)
+			if (((vm_config->guest_flags & GUEST_FLAG_LAPIC_PASSTHROUGH) != 0U)
 					&& ((vm_config->guest_flags & GUEST_FLAG_RT) == 0U)) {
 				ret = false;
 			} else if (vm_config->epc.size != 0UL) {
@@ -151,24 +145,16 @@ bool sanitize_vm_config(void)
 			} else if (is_safety_vm_uuid(vm_config->uuid) && (vm_config->severity != (uint8_t)SEVERITY_SAFETY_VM)) {
 				ret = false;
 			} else {
-				pre_launch_pcpu_bitmap |= vm_config->cpu_affinity;
+				/* nothing to do here */
 			}
 			break;
 		case SOS_VM:
-			/* Deduct pcpus of PRE_LAUNCHED_VMs */
-			vm_config->cpu_affinity = ALL_CPUS_MASK ^ pre_launch_pcpu_bitmap;
-			if ((vm_config->cpu_affinity == 0UL) || (vm_config->severity != (uint8_t)SEVERITY_SOS) ||
+			if ((vm_config->severity != (uint8_t)SEVERITY_SOS) ||
 				((vm_config->guest_flags & GUEST_FLAG_LAPIC_PASSTHROUGH) != 0U)) {
 				ret = false;
 			}
 			break;
 		case POST_LAUNCHED_VM:
-			if ((vm_config->cpu_affinity == 0UL) ||
-				((vm_config->cpu_affinity & pre_launch_pcpu_bitmap) != 0UL)) {
-				pr_err("%s: Post-launch VM has no pcpus or share pcpu with Pre-launch VM!", __func__);
-				ret = false;
-			}
-
 			if ((vm_config->severity == (uint8_t)SEVERITY_SAFETY_VM) ||
 					(vm_config->severity == (uint8_t)SEVERITY_SOS)) {
 				ret = false;
diff --git a/hypervisor/arch/x86/guest/vm.c b/hypervisor/arch/x86/guest/vm.c
index e95ebb9ea..e852ecfe3 100644
--- a/hypervisor/arch/x86/guest/vm.c
+++ b/hypervisor/arch/x86/guest/vm.c
@@ -770,6 +770,7 @@ void prepare_vm(uint16_t vm_id, struct acrn_vm_config *vm_config)
 
 /**
  * @pre vm_config != NULL
+ * @Application constraint: The validity of vm_config->cpu_affinity should be guaranteed before run-time.
  */
 void launch_vms(uint16_t pcpu_id)
 {
@@ -779,11 +780,10 @@ void launch_vms(uint16_t pcpu_id)
 	for (vm_id = 0U; vm_id < CONFIG_MAX_VM_NUM; vm_id++) {
 		vm_config = get_vm_config(vm_id);
 		if ((vm_config->load_order == SOS_VM) || (vm_config->load_order == PRE_LAUNCHED_VM)) {
-			if (vm_config->load_order == SOS_VM) {
-				sos_vm_ptr = &vm_array[vm_id];
-			}
-
 			if (pcpu_id == get_configured_bsp_pcpu_id(vm_config)) {
+				if (vm_config->load_order == SOS_VM) {
+					sos_vm_ptr = &vm_array[vm_id];
+				}
 				prepare_vm(vm_id, vm_config);
 			}
 		}
diff --git a/misc/vm_configs/scenarios/hybrid/vm_configurations.c b/misc/vm_configs/scenarios/hybrid/vm_configurations.c
index 179fd22ef..4d2dfff86 100644
--- a/misc/vm_configs/scenarios/hybrid/vm_configurations.c
+++ b/misc/vm_configs/scenarios/hybrid/vm_configurations.c
@@ -45,6 +45,7 @@ struct acrn_vm_config vm_configs[CONFIG_MAX_VM_NUM] = {
 
 		/* Allow SOS to reboot the host since there is supposed to be the highest severity guest */
 		.guest_flags = 0UL,
+		.cpu_affinity = SOS_VM_CONFIG_CPU_AFFINITY,
 		.memory = {
 			.start_hpa = 0UL,
 			.size = CONFIG_SOS_RAM_SIZE,
diff --git a/misc/vm_configs/scenarios/hybrid/vm_configurations.h b/misc/vm_configs/scenarios/hybrid/vm_configurations.h
index 73db68920..d021753e7 100644
--- a/misc/vm_configs/scenarios/hybrid/vm_configurations.h
+++ b/misc/vm_configs/scenarios/hybrid/vm_configurations.h
@@ -34,6 +34,8 @@
 					SOS_IDLE	\
 					SOS_BOOTARGS_DIFF
 
+#define SOS_VM_CONFIG_CPU_AFFINITY      (AFFINITY_CPU(0U) | AFFINITY_CPU(1U) | AFFINITY_CPU(2U))
+
 #define VM2_CONFIG_CPU_AFFINITY         (AFFINITY_CPU(2U))
 
 #endif /* VM_CONFIGURATIONS_H */
diff --git a/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.c b/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.c
index cfa3e9c21..697484fe5 100644
--- a/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.c
+++ b/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.c
@@ -58,6 +58,7 @@ struct acrn_vm_config vm_configs[CONFIG_MAX_VM_NUM] = {
 
 		/* Allow SOS to reboot the host since there is supposed to be the highest severity guest */
 		.guest_flags = 0UL,
+		.cpu_affinity = SOS_VM_CONFIG_CPU_AFFINITY,
 		.memory = {
 			.start_hpa = 0UL,
 			.size = CONFIG_SOS_RAM_SIZE,
diff --git a/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.h b/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.h
index bebea966e..c3edc6c9c 100644
--- a/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.h
+++ b/misc/vm_configs/scenarios/hybrid_rt/vm_configurations.h
@@ -34,6 +34,8 @@
 					SOS_IDLE	\
 					SOS_BOOTARGS_DIFF
 
+#define SOS_VM_CONFIG_CPU_AFFINITY      (AFFINITY_CPU(0U) | AFFINITY_CPU(1U))
+
 #define VM2_CONFIG_CPU_AFFINITY         (AFFINITY_CPU(1U))
 
 #endif /* VM_CONFIGURATIONS_H */
diff --git a/misc/vm_configs/scenarios/industry/vm_configurations.c b/misc/vm_configs/scenarios/industry/vm_configurations.c
index dd96b39bd..8d191cbd5 100644
--- a/misc/vm_configs/scenarios/industry/vm_configurations.c
+++ b/misc/vm_configs/scenarios/industry/vm_configurations.c
@@ -14,6 +14,7 @@ struct acrn_vm_config vm_configs[CONFIG_MAX_VM_NUM] = {
 
 		/* Allow SOS to reboot the host since there is supposed to be the highest severity guest */
 		.guest_flags = 0UL,
+		.cpu_affinity = SOS_VM_CONFIG_CPU_AFFINITY,
 		.memory = {
 			.start_hpa = 0UL,
 			.size = CONFIG_SOS_RAM_SIZE,
diff --git a/misc/vm_configs/scenarios/industry/vm_configurations.h b/misc/vm_configs/scenarios/industry/vm_configurations.h
index 1591de59d..c42eace93 100644
--- a/misc/vm_configs/scenarios/industry/vm_configurations.h
+++ b/misc/vm_configs/scenarios/industry/vm_configurations.h
@@ -27,6 +27,8 @@
 					SOS_IDLE	\
 					SOS_BOOTARGS_DIFF
 
+#define SOS_VM_CONFIG_CPU_AFFINITY      (AFFINITY_CPU(0U) | AFFINITY_CPU(1U) | AFFINITY_CPU(2U) | AFFINITY_CPU(3U))
+
 #define VM1_CONFIG_CPU_AFFINITY         (AFFINITY_CPU(0U) | AFFINITY_CPU(1U))
 #define VM2_CONFIG_CPU_AFFINITY         (AFFINITY_CPU(2U) | AFFINITY_CPU(3U))
 #define VM3_CONFIG_CPU_AFFINITY         (AFFINITY_CPU(0U) | AFFINITY_CPU(1U))