Re: [PATCH 1/4] target/riscv: Make MPV only work when MPP != PRV_M

[LIU Zhiwei <zhiwei_liu@linux.alibaba.com>]

On 2023/5/29 20:17, Weiwei Li wrote:
> Upon MRET or explicit memory access with MPRV=1, MPV should be ignored
> when MPP=PRV_M.
Does MPP==PRV_M always indicate the MPV==0?

Zhiwei

>
> Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
> ---
>   target/riscv/cpu_helper.c | 3 ++-
>   target/riscv/op_helper.c  | 3 ++-
>   2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> index 09ea227ceb..bd892c05d4 100644
> --- a/target/riscv/cpu_helper.c
> +++ b/target/riscv/cpu_helper.c
> @@ -46,7 +46,8 @@ int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
>   
>           if (mode == PRV_M && get_field(status, MSTATUS_MPRV)) {
>               mode = get_field(env->mstatus, MSTATUS_MPP);
> -            virt = get_field(env->mstatus, MSTATUS_MPV);
> +            virt = get_field(env->mstatus, MSTATUS_MPV) &&
> +                   (mode != PRV_M);
>               if (virt) {
>                   status = env->vsstatus;
>               }
> diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c
> index f563dc3981..9cdb9cdd06 100644
> --- a/target/riscv/op_helper.c
> +++ b/target/riscv/op_helper.c
> @@ -335,7 +335,8 @@ target_ulong helper_mret(CPURISCVState *env)
>           riscv_raise_exception(env, RISCV_EXCP_INST_ACCESS_FAULT, GETPC());
>       }
>   
> -    target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV);
> +    target_ulong prev_virt = get_field(env->mstatus, MSTATUS_MPV) &&
> +                             (prev_priv != PRV_M);
>       mstatus = set_field(mstatus, MSTATUS_MIE,
>                           get_field(mstatus, MSTATUS_MPIE));
>       mstatus = set_field(mstatus, MSTATUS_MPIE, 1);