diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 18e974a34fce..a7177c284f9b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -4212,11 +4212,13 @@ static int kvmhv_configure_mmu(struct kvm *kvm, struct kvm_ppc_mmuv3_cfg *cfg)
 	if ((cfg->process_table & PRTS_MASK) > 24)
 		return -EINVAL;
 
+	mutex_lock(&kvm->lock);
 	kvm->arch.process_table = cfg->process_table;
 	kvmppc_setup_partition_table(kvm);
 
 	lpcr = (cfg->flags & KVM_PPC_MMUV3_GTSE) ? LPCR_GTSE : 0;
 	kvmppc_update_lpcr(kvm, lpcr, LPCR_GTSE);
+	mutex_unlock(&kvm->lock);
 
 	return 0;
 }