Re: [PATCH 07/10] target/arm: SCR_EL3.RW should be treated as 1 if EL2 doesn't support AArch32

[Richard Henderson <richard.henderson@linaro.org>]

On 3/6/25 08:39, Peter Maydell wrote:
> +/* Return the effective value of SCR_EL3.RW */
> +static inline bool arm_scr_rw_eff(CPUARMState *env)
> +{
> +    /*
> +     * SCR_EL3.RW has an effective value of 1 if:
> +     *  - we are NS and EL2 is implemented but doesn't support AArch32
> +     *  - we are S and EL2 is enabled (in which case it must be AArch64)
> +     */
> +    ARMCPU *cpu = env_archcpu(env);
> +    bool ns_and_no_aarch32_el2 = arm_feature(env, ARM_FEATURE_EL2) &&
> +        (env->cp15.scr_el3 & SCR_NS) &&
> +        !cpu_isar_feature(aa64_aa32_el1, cpu);
> +    bool s_and_el2_enabled =
> +        (env->cp15.scr_el3 & (SCR_NS | SCR_EEL2)) == SCR_EEL2;
> +
> +    return ns_and_no_aarch32_el2 || s_and_el2_enabled ||
> +        (env->cp15.scr_el3 & SCR_RW);
> +}

The computation here can be simplified.

     if (env->cp15.scr_el3 & SCR_RW) {
         return true;
     }
     if (env->cp15.scr_el3 & SCR_NS) {
         return arm_feature(env, ARM_FEATURE_EL2) &&
                !cpu_isar_feature(aa64_aa32_el1, cpu);
     } else {
         return env->cp15.scr_el3 & SCR_EEL2;
     }

Otherwise,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~