1 files changed, 11 insertions, 0 deletions
diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index f414aaebdb..2baf5bc3ca 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -380,6 +380,17 @@ void helper_wfi(CPURISCVState *env)
     }
 }
 
+void helper_wrs_nto(CPURISCVState *env)
+{
+    if (env->virt_enabled && (env->priv == PRV_S || env->priv == PRV_U) &&
+        get_field(env->hstatus, HSTATUS_VTW) &&
+        !get_field(env->mstatus, MSTATUS_TW)) {
+        riscv_raise_exception(env, RISCV_EXCP_VIRT_INSTRUCTION_FAULT, GETPC());
+    } else if (env->priv != PRV_M && get_field(env->mstatus, MSTATUS_TW)) {
+        riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
+    }
+}
+
 void helper_tlb_flush(CPURISCVState *env)
 {
     CPUState *cs = env_cpu(env);