Re: [RFC PATCH v8 09/23] target/arm: Handle PSTATE.ALLINT on taking an exception

[Peter Maydell]

On Mon, 18 Mar 2024 at 09:37, Jinjie Ruan <ruanjinjie@huawei.com> wrote:
>
> Set or clear PSTATE.ALLINT on taking an exception to ELx according to the
> SCTLR_ELx.SPINTMASK bit.
>
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> v3:
> - Add Reviewed-by.
> ---
>  target/arm/helper.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 4bc63bf7ca..81f4a8f194 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -11705,6 +11705,15 @@ static void arm_cpu_do_interrupt_aarch64(CPUState 
> *cs)
>          }
>      }
>
> +    if (cpu_isar_feature(aa64_nmi, cpu) &&
> +        (env->cp15.sctlr_el[new_el] & SCTLR_NMI)) {

This shouldn't be checking the value of SCTLR_NMI here:
the new PSTATE.ALLINT is set to !SPINTMASK even if NMI == 0.
(The SPINTMASK bit description is a bit confusing, but
the correct behaviour is clear in the AArch64.TakeException()
pseudocode.)

> +        if (!(env->cp15.sctlr_el[new_el] & SCTLR_SPINTMASK)) {
> +            new_mode |= PSTATE_ALLINT;
> +        } else {
> +            new_mode &= ~PSTATE_ALLINT;
> +        }
> +    }
> +
>      pstate_write(env, PSTATE_DAIF | new_mode);
>      env->aarch64 = true;
>      aarch64_restore_sp(env, new_el);
> --
> 2.34.1
>

thanks
-- PMM