Re: [PATCH] riscv: Set xPIE to 1 after xRET

[Alistair Francis]

On Fri, Jan 3, 2020 at 12:01 AM Yiting Wang <address@hidden> wrote:
>
> When executing an xRET instruction, supposing xPP holds the
> value y, xIE is set to xPIE; the privilege mode is changed to y;
> xPIE is set to 1. But QEMU sets xPIE to 0 incorrectly.
>
> Signed-off-by: Yiting Wang <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Alistair

> ---
>  target/riscv/op_helper.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index 331cc36..e87c911 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -93,7 +93,7 @@ target_ulong helper_sret(CPURISCVState *env, target_ulong 
> cpu_pc_deb)
>          env->priv_ver >= PRIV_VERSION_1_10_0 ?
>          MSTATUS_SIE : MSTATUS_UIE << prev_priv,
>          get_field(mstatus, MSTATUS_SPIE));
> -    mstatus = set_field(mstatus, MSTATUS_SPIE, 0);
> +    mstatus = set_field(mstatus, MSTATUS_SPIE, 1);
>      mstatus = set_field(mstatus, MSTATUS_SPP, PRV_U);
>      riscv_cpu_set_mode(env, prev_priv);
>      env->mstatus = mstatus;
> @@ -118,7 +118,7 @@ target_ulong helper_mret(CPURISCVState *env, target_ulong 
> cpu_pc_deb)
>          env->priv_ver >= PRIV_VERSION_1_10_0 ?
>          MSTATUS_MIE : MSTATUS_UIE << prev_priv,
>          get_field(mstatus, MSTATUS_MPIE));
> -    mstatus = set_field(mstatus, MSTATUS_MPIE, 0);
> +    mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
>      mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
>      riscv_cpu_set_mode(env, prev_priv);
>      env->mstatus = mstatus;
> --
> 2.7.4
>
>