Re: [PATCH v2 03/24] target/riscv: save and restore elp state on priv transitions

[Deepak Gupta]

Thanks Richard.

On Tue, Jul 30, 2024 at 09:04:29AM +1000, Richard Henderson wrote:
> On 7/30/24 03:53, Deepak Gupta wrote:
> > elp state is recorded in *status on trap entry (less privilege to higher
> > privilege) and restored in elp from *status on trap exit (higher to less
> > privilege).
> >
> > Additionally this patch introduces a forward cfi helper function to
> > determine if current privilege has forward cfi is enabled or not based on
> > *envcfg (for U, VU, S, VU, HS) or mseccfg csr (for M). For qemu-user, a
> > new field `ufcfien` is introduced which is by default set to false and
> > helper function returns value deposited in `ufcfien` for qemu-user.
>
> Why are you using a different field for qemu-user?
> Much better to simply configure menvcfg the same as for system mode.


I am assuming `CONFIG_USER_ONLY` is set for qemu-user builds and unset
for `not qemu-user` builds. Let me know if I got that right?

`menvcfg` (and a lot of other system related fields CPUArchstate for riscv)
are wrapped under `#ifndef CONFIG_USER_ONLY`. So `menvcfg` field is not
available for qemu-user compile.


> > +        return (env->menvcfg & MENVCFG_LPE) ? true : false;
>
> Never use ?: with true/false.  Use the correct boolean expression in 
> the first place, which in this case is just the & expression.

Noted.
Will fix this and other instances in patch series.

> r~