Re: [RFC PATCH v2 04/22] target/arm: Implement ALLINT MSR (immediate)

[Richard Henderson]

On 2/21/24 10:41, Richard Henderson wrote:
> Ho hum..  I just noticed that TALLINT only traps immediate write of 1, not also immediate 
> write of 0.  So one helper for both MSR Xt and MSR imm is not practical.

Quick follow up to say that means you can do

static bool trans_MSR_i_ALLINT(DisasContext *s, arg_i *a)
{
    if (!dc_isar_feature(aa64_nmi, s)
        || s->current_el == 0
        || (a->imm & ~1)) {
        return false;
    }
    if (!a->imm) {
        clear_pstate_bits(PSTATE_ALLINT);
    } else if (arm_dc_feature(s, ARM_FEATURE_EL2) && s->current_el == 1) {
        /* Use helper for runtime check against HCRX_EL2.TALLINT. */
        gen_helper_msr_set_allint_el1(tcg_env);
    } else {
        set_pstate_bits(PSTATE_ALLINT);
    }
    return true;
}

Generate inline bit ops whenever TALLINT does not apply.
This also means the helper need not check current_el, because we've already 
done it here.


r~