Re: [PATCH v3 1/8] target/arm: Add ID_AA64ISAR2_EL1

[Richard Henderson]

On 3/22/23 13:25, Aaron Lindsay wrote:
> --- a/target/arm/hvf/hvf.c
> +++ b/target/arm/hvf/hvf.c
> @@ -507,6 +507,7 @@ static bool 
> hvf_arm_get_host_cpu_features(ARMHostCPUFeatures *ahcf)
>           { HV_SYS_REG_ID_AA64DFR1_EL1, &host_isar.id_aa64dfr1 },
>           { HV_SYS_REG_ID_AA64ISAR0_EL1, &host_isar.id_aa64isar0 },
>           { HV_SYS_REG_ID_AA64ISAR1_EL1, &host_isar.id_aa64isar1 },
> +        { HV_SYS_REG_ID_AA64ISAR2_EL1, &host_isar.id_aa64isar2 },

Ah, I may have given you a bum steer here.
In MacOSX 12.6, there is no HV_SYS_REG_ID_AA64ISAR2_EL1 enumerator.

Irritatingly, it is an enum not a define we can test via the preprocessor.
In addition, the form of the enum,

    HV_SYS_REG_ID_AA64ISAR0_EL1 = 0xc030,
    HV_SYS_REG_ID_AA64ISAR1_EL1 = 0xc031,
    HV_SYS_REG_ID_AA64MMFR0_EL1 = 0xc038,
    HV_SYS_REG_ID_AA64MMFR1_EL1 = 0xc039,

suggests an encoding of the system register number, so we would eventually be able to use 
0xc032.  But I wouldn't want to try that without the interface being properly exposed.  I 
don't know if some later version of MacOS already does so.

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


r~