diff --git a/target/riscv/helper.h b/target/riscv/helper.h
index 227c7122ef..9792ab5086 100644
--- a/target/riscv/helper.h
+++ b/target/riscv/helper.h
@@ -3,6 +3,7 @@ DEF_HELPER_2(raise_exception, noreturn, env, i32)
 
 /* Floating Point - rounding mode */
 DEF_HELPER_FLAGS_2(set_rounding_mode, TCG_CALL_NO_WG, void, env, i32)
+DEF_HELPER_FLAGS_2(set_rounding_mode_chkfrm, TCG_CALL_NO_WG, void, env, i32)
 DEF_HELPER_FLAGS_1(set_rod_rounding_mode, TCG_CALL_NO_WG, void, env)
 
 /* Floating Point - fused */
diff --git a/target/riscv/fpu_helper.c b/target/riscv/fpu_helper.c
index 5699c9517f..96817df8ef 100644
--- a/target/riscv/fpu_helper.c
+++ b/target/riscv/fpu_helper.c
@@ -81,6 +81,43 @@ void helper_set_rounding_mode(CPURISCVState *env, uint32_t rm)
     set_float_rounding_mode(softrm, &env->fp_status);
 }
 
+void helper_set_rounding_mode_chkfrm(CPURISCVState *env, uint32_t rm)
+{
+    int softrm;
+
+    /* Always validate frm, even if rm != DYN. */
+    if (unlikely(env->frm >= 5)) {
+        riscv_raise_exception(env, RISCV_EXCP_ILLEGAL_INST, GETPC());
+    }
+    if (rm == RISCV_FRM_DYN) {
+        rm = env->frm;
+    }
+    switch (rm) {
+    case RISCV_FRM_RNE:
+        softrm = float_round_nearest_even;
+        break;
+    case RISCV_FRM_RTZ:
+        softrm = float_round_to_zero;
+        break;
+    case RISCV_FRM_RDN:
+        softrm = float_round_down;
+        break;
+    case RISCV_FRM_RUP:
+        softrm = float_round_up;
+        break;
+    case RISCV_FRM_RMM:
+        softrm = float_round_ties_away;
+        break;
+    case RISCV_FRM_ROD:
+        softrm = float_round_to_odd;
+        break;
+    default:
+        g_assert_not_reached();
+    }
+
+    set_float_rounding_mode(softrm, &env->fp_status);
+}
+
 void helper_set_rod_rounding_mode(CPURISCVState *env)
 {
     set_float_rounding_mode(float_round_to_odd, &env->fp_status);
diff --git a/target/riscv/translate.c b/target/riscv/translate.c
index df38db7553..493c3815e1 100644
--- a/target/riscv/translate.c
+++ b/target/riscv/translate.c
@@ -114,6 +114,8 @@ typedef struct DisasContext {
     bool pm_base_enabled;
     /* Use icount trigger for native debug */
     bool itrigger;
+    /* FRM is known to contain a valid value. */
+    bool frm_valid;
     /* TCG of the current insn_start */
     TCGOp *insn_start;
 } DisasContext;
@@ -674,12 +676,29 @@ static void gen_set_rm(DisasContext *ctx, int rm)
         gen_helper_set_rod_rounding_mode(cpu_env);
         return;
     }
+    if (rm == RISCV_FRM_DYN) {
+        /* The helper will return only if frm valid. */
+        ctx->frm_valid = true;
+    }
 
     /* The helper may raise ILLEGAL_INSN -- record binv for unwind. */
     decode_save_opc(ctx);
     gen_helper_set_rounding_mode(cpu_env, tcg_constant_i32(rm));
 }
 
+static void gen_set_rm_chkfrm(DisasContext *ctx, int rm)
+{
+    if (ctx->frm == rm && ctx->frm_valid) {
+        return;
+    }
+    ctx->frm = rm;
+    ctx->frm_valid = true;
+
+    /* The helper may raise ILLEGAL_INSN -- record binv for unwind. */
+    decode_save_opc(ctx);
+    gen_helper_set_rounding_mode_chkfrm(cpu_env, tcg_constant_i32(rm));
+}
+
 static int ex_plus_1(DisasContext *ctx, int nf)
 {
     return nf + 1;
diff --git a/target/riscv/insn_trans/trans_rvv.c.inc b/target/riscv/insn_trans/trans_rvv.c.inc
index d455acedbf..bbb5c3a7b5 100644
--- a/target/riscv/insn_trans/trans_rvv.c.inc
+++ b/target/riscv/insn_trans/trans_rvv.c.inc
@@ -2679,13 +2679,9 @@ static bool do_opfv(DisasContext *s, arg_rmr *a,
                     int rm)
 {
     if (checkfn(s, a)) {
-        if (rm != RISCV_FRM_DYN) {
-            gen_set_rm(s, RISCV_FRM_DYN);
-        }
-
         uint32_t data = 0;
         TCGLabel *over = gen_new_label();
-        gen_set_rm(s, rm);
+        gen_set_rm_chkfrm(s, rm);
         tcg_gen_brcondi_tl(TCG_COND_EQ, cpu_vl, 0, over);
         tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over);
 
@@ -2882,17 +2878,13 @@ static bool opffv_widen_check(DisasContext *s, arg_rmr *a)
 static bool trans_##NAME(DisasContext *s, arg_rmr *a)              \
 {                                                                  \
     if (CHECK(s, a)) {                                             \
-        if (FRM != RISCV_FRM_DYN) {                                \
-            gen_set_rm(s, RISCV_FRM_DYN);                          \
-        }                                                          \
-                                                                   \
         uint32_t data = 0;                                         \
         static gen_helper_gvec_3_ptr * const fns[2] = {            \
             gen_helper_##HELPER##_h,                               \
             gen_helper_##HELPER##_w,                               \
         };                                                         \
         TCGLabel *over = gen_new_label();                          \
-        gen_set_rm(s, FRM);                                        \
+        gen_set_rm_chkfrm(s, FRM);                                 \
         tcg_gen_brcondi_tl(TCG_COND_EQ, cpu_vl, 0, over);          \
         tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over); \
                                                                    \
@@ -3005,17 +2997,13 @@ static bool opffv_narrow_check(DisasContext *s, arg_rmr *a)
 static bool trans_##NAME(DisasContext *s, arg_rmr *a)              \
 {                                                                  \
     if (CHECK(s, a)) {                                             \
-        if (FRM != RISCV_FRM_DYN) {                                \
-            gen_set_rm(s, RISCV_FRM_DYN);                          \
-        }                                                          \
-                                                                   \
         uint32_t data = 0;                                         \
         static gen_helper_gvec_3_ptr * const fns[2] = {            \
             gen_helper_##HELPER##_h,                               \
             gen_helper_##HELPER##_w,                               \
         };                                                         \
         TCGLabel *over = gen_new_label();                          \
-        gen_set_rm(s, FRM);                                        \
+        gen_set_rm_chkfrm(s, FRM);                                 \
         tcg_gen_brcondi_tl(TCG_COND_EQ, cpu_vl, 0, over);          \
         tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over); \
                                                                    \
@@ -3060,10 +3048,6 @@ static bool opxfv_narrow_check(DisasContext *s, arg_rmr *a)
 static bool trans_##NAME(DisasContext *s, arg_rmr *a)              \
 {                                                                  \
     if (opxfv_narrow_check(s, a)) {                                \
-        if (FRM != RISCV_FRM_DYN) {                                \
-            gen_set_rm(s, RISCV_FRM_DYN);                          \
-        }                                                          \
-                                                                   \
         uint32_t data = 0;                                         \
         static gen_helper_gvec_3_ptr * const fns[3] = {            \
             gen_helper_##HELPER##_b,                               \
@@ -3071,7 +3055,7 @@ static bool trans_##NAME(DisasContext *s, arg_rmr *a)              \
             gen_helper_##HELPER##_w,                               \
         };                                                         \
         TCGLabel *over = gen_new_label();                          \
-        gen_set_rm(s, FRM);                                        \
+        gen_set_rm_chkfrm(s, FRM);                                 \
         tcg_gen_brcondi_tl(TCG_COND_EQ, cpu_vl, 0, over);          \
         tcg_gen_brcond_tl(TCG_COND_GEU, cpu_vstart, cpu_vl, over); \
                                                                    \
