Re: [PATCH v3 37/51] target/arm: Reset streaming sve state on exception boundaries

[Peter Maydell]

On Mon, 20 Jun 2022 at 19:14, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> We can handle both exception entry and exception return by
> hooking into aarch64_sve_change_el.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  target/arm/helper.c | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 26f4a4bc26..9c5b1a10eb 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -11754,6 +11754,19 @@ void aarch64_sve_change_el(CPUARMState *env, int 
> old_el,
>          return;
>      }
>
> +    old_a64 = old_el ? arm_el_is_aa64(env, old_el) : el0_a64;
> +    new_a64 = new_el ? arm_el_is_aa64(env, new_el) : el0_a64;
> +
> +    /*
> +     * Both AArch64.TakeException and AArch64.ExceptionReturn
> +     * invoke ResetSVEState when taking an exception from, or
> +     * returning to, AArch32 state when PSTATE.SM is enabled.
> +     */
> +    if (old_a64 != new_a64 && FIELD_EX64(env->svcr, SVCR, SM)) {
> +        arm_reset_sve_state(env);
> +        return;
> +    }

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM