Re: [PATCH 24/35] target/arm: Handle FEAT_NV2 changes to when SPSR_EL1.M reports EL2

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

On 12/18/23 22:32, Peter Maydell wrote:
> With FEAT_NV2, the condition for when SPSR_EL1.M should report that
> an exception was taken from EL2 changes.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   target/arm/helper.c | 16 ++++++++++++----
>   1 file changed, 12 insertions(+), 4 deletions(-)
> 
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 45444360f95..38e16c2f8a5 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -11405,10 +11405,18 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs)
>           aarch64_save_sp(env, arm_current_el(env));
>           env->elr_el[new_el] = env->pc;
>   
> -        if (cur_el == 1 && new_el == 1 &&
> -            ((arm_hcr_el2_eff(env) & (HCR_NV | HCR_NV1)) == HCR_NV)) {
> -            /* I_ZJRNN: report EL2 in the SPSR by setting M[3:2] to 0b10 */
> -            old_mode = deposit32(old_mode, 2, 2, 2);
> +        if (cur_el == 1 && new_el == 1) {
> +            uint64_t hcr = arm_hcr_el2_eff(env);
> +            if ((hcr & (HCR_NV | HCR_NV1 | HCR_NV2)) == HCR_NV ||
> +                (hcr & (HCR_NV | HCR_NV2)) == (HCR_NV | HCR_NV2)) {

Maybe clearer as

	if ((hcr & HCR_NV) && ((hcr & HCR_NV2) || !(hcr & HCR_NV1)))

?

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


r~

> +                /*
> +                 * FEAT_NV, FEAT_NV2 may need to report EL2 in the SPSR
> +                 * by setting M[3:2] to 0b10.
> +                 * If NV2 is disabled, change SPSR when NV,NV1 == 1,0 (I_ZJRNN)
> +                 * If NV2 is enabled, change SPSR when NV is 1 (I_DBTLM)
> +                 */
> +                old_mode = deposit32(old_mode, 2, 2, 2);
> +            }
>           }
>       } else {
>           old_mode = cpsr_read_for_spsr_elx(env);