When the Ssdbltrp extension is enabled, SSTATUS.MDT field is cleared
when executing sret if executed in M-mode. When executing mret/mnret,
SSTATUS.MDT is cleared.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
---
 target/riscv/op_helper.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
index dabc74de39..64c5792af8 100644
--- a/target/riscv/op_helper.c
+++ b/target/riscv/op_helper.c
@@ -299,6 +299,9 @@ target_ulong helper_sret(CPURISCVState *env)
         }
         mstatus = set_field(mstatus, MSTATUS_SDT, 0);
     }
+    if (riscv_cpu_cfg(env)->ext_smdbltrp && env->priv >= PRV_M) {
+        mstatus = set_field(mstatus, MSTATUS_MDT, 0);
+    }
     if (env->priv_ver >= PRIV_VERSION_1_12_0) {
         mstatus = set_field(mstatus, MSTATUS_MPRV, 0);
     }
@@ -375,6 +378,9 @@ target_ulong helper_mret(CPURISCVState *env)
     if (riscv_cpu_cfg(env)->ext_ssdbltrp) {
         mstatus = ssdbltrp_mxret(env, mstatus, prev_priv, prev_virt);
     }
+    if (riscv_cpu_cfg(env)->ext_smdbltrp) {
+        mstatus = set_field(mstatus, MSTATUS_MDT, 0);
+    }
     if ((env->priv_ver >= PRIV_VERSION_1_12_0) && (prev_priv != PRV_M)) {
         mstatus = set_field(mstatus, MSTATUS_MPRV, 0);
     }
@@ -412,6 +418,12 @@ target_ulong helper_mnret(CPURISCVState *env)
         env->mstatus = ssdbltrp_mxret(env, env->mstatus, prev_priv, prev_virt);
     }
 
+    if (riscv_cpu_cfg(env)->ext_smdbltrp) {
+        if (prev_priv < PRV_M) {
+            env->mstatus = set_field(env->mstatus, MSTATUS_MDT, false);
+        }
+    }
+
     if (riscv_has_ext(env, RVH) && prev_virt) {
         riscv_cpu_swap_hypervisor_regs(env);
     }
-- 
2.45.2

On Fri, Oct 18, 2024 at 12:54 AM Clément Léger <cleger@rivosinc.com> wrote:
>
> When the Ssdbltrp extension is enabled, SSTATUS.MDT field is cleared
> when executing sret if executed in M-mode. When executing mret/mnret,
> SSTATUS.MDT is cleared.
>
> Signed-off-by: Clément Léger <cleger@rivosinc.com>
> ---
>  target/riscv/op_helper.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index dabc74de39..64c5792af8 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -299,6 +299,9 @@ target_ulong helper_sret(CPURISCVState *env)
>          }
>          mstatus = set_field(mstatus, MSTATUS_SDT, 0);
>      }
> +    if (riscv_cpu_cfg(env)->ext_smdbltrp && env->priv >= PRV_M) {
> +        mstatus = set_field(mstatus, MSTATUS_MDT, 0);
> +    }
>      if (env->priv_ver >= PRIV_VERSION_1_12_0) {
>          mstatus = set_field(mstatus, MSTATUS_MPRV, 0);
>      }
> @@ -375,6 +378,9 @@ target_ulong helper_mret(CPURISCVState *env)
>      if (riscv_cpu_cfg(env)->ext_ssdbltrp) {
>          mstatus = ssdbltrp_mxret(env, mstatus, prev_priv, prev_virt);
>      }
> +    if (riscv_cpu_cfg(env)->ext_smdbltrp) {
> +        mstatus = set_field(mstatus, MSTATUS_MDT, 0);
> +    }
>      if ((env->priv_ver >= PRIV_VERSION_1_12_0) && (prev_priv != PRV_M)) {
>          mstatus = set_field(mstatus, MSTATUS_MPRV, 0);
>      }
> @@ -412,6 +418,12 @@ target_ulong helper_mnret(CPURISCVState *env)
>          env->mstatus = ssdbltrp_mxret(env, env->mstatus, prev_priv, prev_virt);
>      }
>
> +    if (riscv_cpu_cfg(env)->ext_smdbltrp) {
> +        if (prev_priv < PRV_M) {
> +            env->mstatus = set_field(env->mstatus, MSTATUS_MDT, false);

0 instead of false, otherwise

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> +        }
> +    }
> +
>      if (riscv_has_ext(env, RVH) && prev_virt) {
>          riscv_cpu_swap_hypervisor_regs(env);
>      }
> --
> 2.45.2
>
>