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Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing
From: |
Alistair Francis |
Subject: |
Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET |
Date: |
Thu, 6 Apr 2023 10:43:04 +1000 |
On Thu, Mar 30, 2023 at 11:59 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
>
> The MPP will be set to the least-privileged supported mode (U if
> U-mode is implemented, else M).
I don't think this is right, the spec in section 8.6.4 says this:
"MRET then in mstatus/mstatush sets MPV=0, MPP=0,
MIE=MPIE, and MPIE=1"
So it should just always be 0 (PRV_U is 0)
Alistair
>
> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
> ---
> target/riscv/op_helper.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index 84ee018f7d..991f06d98d 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -339,7 +339,8 @@ target_ulong helper_mret(CPURISCVState *env)
> mstatus = set_field(mstatus, MSTATUS_MIE,
> get_field(mstatus, MSTATUS_MPIE));
> mstatus = set_field(mstatus, MSTATUS_MPIE, 1);
> - mstatus = set_field(mstatus, MSTATUS_MPP, PRV_U);
> + mstatus = set_field(mstatus, MSTATUS_MPP,
> + riscv_has_ext(env, RVU) ? PRV_U : PRV_M);
> mstatus = set_field(mstatus, MSTATUS_MPV, 0);
> if ((env->priv_ver >= PRIV_VERSION_1_12_0) && (prev_priv != PRV_M)) {
> mstatus = set_field(mstatus, MSTATUS_MPRV, 0);
> --
> 2.25.1
>
>
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET,
Alistair Francis <=
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, liweiwei, 2023/04/05
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, Alistair Francis, 2023/04/05
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, liweiwei, 2023/04/05
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, Alistair Francis, 2023/04/05
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, liweiwei, 2023/04/05
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, liweiwei, 2023/04/05
- Re: [PATCH 1/2] target/riscv: Fix the mstatus.MPP value after executing MRET, Alistair Francis, 2023/04/05