On Thu, Jun 24, 2021 at 11:48 PM Jose Martins <josemartin...@gmail.com> wrote:
>
> > > +static const target_ulong vs_delegable_excps = delegable_excps &
> > > + ~((1ULL << (RISCV_EXCP_S_ECALL)) |
> >
> > > + (1ULL << (RISCV_EXCP_VS_ECALL)) |
> > > + (1ULL << (RISCV_EXCP_M_ECALL)) |
> >
> > These two are both read only 0, shouldn't they not be included in this list?
> >
> > > static int write_hedeleg(CPURISCVState *env, int csrno, target_ulong val)
> > > {
> > > - env->hedeleg = val;
> > > + env->hedeleg = val & vs_delegable_excps;
> >
> > Because we then allow a write to occur here.
>
> Note that the list is being bitwise negated, so both of these are
> actually not writable (ie read-only 0). There is still the question
> regarding the VS_ECALL (exception 10) bit raised by Zhiwei, since
> table 5.2 in the spec does not explicitly classify it. However, I
> believe it is safe to assume that exception 10 is non-delegable.
Ah, I see.
Reviewed-by: Alistair Francis <alistair.fran...@wdc.com>
Applied to riscv-to-apply.next
I improved the indentation and rebased this on the latest master.
Alistair
>
> José
