diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index c172f9b212d1..b4182ca4435f 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -440,6 +440,7 @@ struct kvm_vcpu_arch {
 	bool skey_enabled;
 	/* Indicator if the access registers have been loaded from guest */
 	bool acrs_loaded;
+	bool initialized;
 	struct kvm_s390_pv_vcpu pv;
 	union diag318_info diag318_info;
 	struct kvm_s390_mmu_cache *mc;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 150b5dd2170e..f86b4b0b356f 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3613,6 +3613,9 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 	if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0 ||
 	    vcpu->kvm->arch.user_operexec)
 		vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
+
+	/* Pairs with smp_load_acquire() in kvm_arch_vcpu_ioctl_run() and kvm_arch_vcpu_ioctl() */
+	smp_store_release(&vcpu->arch.initialized, true);
 }
 
 static bool kvm_has_pckmo_subfunc(struct kvm *kvm, unsigned long nr)
@@ -5039,6 +5042,10 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 	    kvm_run->kvm_dirty_regs & ~KVM_SYNC_S390_VALID_FIELDS)
 		return -EINVAL;
 
+	/* Pairs with smp_store_release() in kvm_arch_vcpu_postcreate() */
+	if (!smp_load_acquire(&vcpu->arch.initialized))
+		return -EINVAL;
+
 	vcpu_load(vcpu);
 
 	if (guestdbg_exit_pending(vcpu)) {
@@ -5523,6 +5530,10 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
 	long r;
 	u16 rc, rrc;
 
+	/* Pairs with smp_store_release() in kvm_arch_vcpu_postcreate() */
+	if (!smp_load_acquire(&vcpu->arch.initialized))
+		return -EINVAL;
+
 	vcpu_load(vcpu);
 
 	switch (ioctl) {