Re: [PATCH 2/4] target/riscv: Remove check on mode for MPRV

[Weiwei Li]

On 2023/6/1 13:27, Alistair Francis wrote:
> On Mon, May 29, 2023 at 10:19 PM Weiwei Li <liweiwei@iscas.ac.cn> wrote:
> > Normally, MPRV can be set to 1 only in M mode (It will be cleared
> > when returning to lower-privilege mode by MRET/SRET).
> >
> > Signed-off-by: Weiwei Li <liweiwei@iscas.ac.cn>
> > Signed-off-by: Junqiang Wang <wangjunqiang@iscas.ac.cn>
> > ---
> >   target/riscv/cpu_helper.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> > index bd892c05d4..45baf95c77 100644
> > --- a/target/riscv/cpu_helper.c
> > +++ b/target/riscv/cpu_helper.c
> > @@ -44,7 +44,7 @@ int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch)
> >       if (!ifetch) {
> >           uint64_t status = env->mstatus;
> >
> > -        if (mode == PRV_M && get_field(status, MSTATUS_MPRV)) {
> > +        if (get_field(status, MSTATUS_MPRV)) {
> The original check is correct though, why remove it?

Yeah. As described in the commit message, I think MPRV can only be set 
to 1 in M mode normally

which means check on MPRV is enough in this case. So I remove the check 
on mode here.

Regards,

Weiwei Li

> Alistair
>
> >               mode = get_field(env->mstatus, MSTATUS_MPP);
> >               virt = get_field(env->mstatus, MSTATUS_MPV) &&
> >                      (mode != PRV_M);
> > --
> > 2.25.1