Re: [PATCH v1 21/28] target/riscv: Respect MPRV and SPRV for floating point ops

[Alistair Francis]

On Wed, Oct 2, 2019 at 4:52 PM Palmer Dabbelt <address@hidden> wrote:
>
> On Fri, 23 Aug 2019 16:38:44 PDT (-0700), Alistair Francis wrote:
> > Respect the contents of MSTATUS.MPRV and HSTATUS.SPRV when performing
> > floating point operations when V=0.
>
> I'm confused as to what this has to do with floating point.

virt_enabled is only checked in mark_fs_dirty() for floating point support.

Alistair

>
> >
> > Signed-off-by: Alistair Francis <address@hidden>
> > ---
> >  target/riscv/translate.c | 16 +++++++++++++++-
> >  1 file changed, 15 insertions(+), 1 deletion(-)
> >
> > diff --git a/target/riscv/translate.c b/target/riscv/translate.c
> > index 19771904f4..ea19ba9c5d 100644
> > --- a/target/riscv/translate.c
> > +++ b/target/riscv/translate.c
> > @@ -750,7 +750,21 @@ static void 
> > riscv_tr_init_disas_context(DisasContextBase *dcbase, CPUState *cs)
> >      ctx->mstatus_fs = ctx->base.tb->flags & TB_FLAGS_MSTATUS_FS;
> >      ctx->priv_ver = env->priv_ver;
> >  #if !defined(CONFIG_USER_ONLY)
> > -    ctx->virt_enabled = riscv_cpu_virt_enabled(env);
> > +    if (riscv_has_ext(env, RVH)) {
> > +        ctx->virt_enabled = riscv_cpu_virt_enabled(env);
> > +        if (env->priv_ver == PRV_M &&
> > +            get_field(*env->mstatus, MSTATUS_MPRV) &&
> > +            get_field(*env->mstatus, MSTATUS_MPV)) {
> > +            ctx->virt_enabled = true;
> > +        } else if (env->priv == PRV_S &&
> > +                   !riscv_cpu_virt_enabled(env) &&
> > +                   get_field(env->hstatus, HSTATUS_SPRV) &&
> > +                   get_field(env->hstatus, HSTATUS_SPV)) {
> > +            ctx->virt_enabled = true;
> > +        }
> > +    } else {
> > +        ctx->virt_enabled = false;
> > +    }
> >  #else
> >      ctx->virt_enabled = false;
> >  #endif