Re: [Qemu-devel] [PATCH] s390x/cpumodels: add z14 Model ZR1

[David Hildenbrand]

On 13.06.2018 10:18, Christian Borntraeger wrote:
> introduce the new z14 Model ZR1 cpu model. Mostly identical to z14, only
> the cpu type differs (3906 vs. 3907)
> 
> Signed-off-by: Christian Borntraeger <address@hidden>
> ---
>  target/s390x/cpu_models.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/target/s390x/cpu_models.c b/target/s390x/cpu_models.c
> index e10035aaa8..cfdbccf46d 100644
> --- a/target/s390x/cpu_models.c
> +++ b/target/s390x/cpu_models.c
> @@ -79,6 +79,7 @@ static S390CPUDef s390_cpu_defs[] = {
>      CPUDEF_INIT(0x2964, 13, 2, 47, 0x08000000U, "z13.2", "IBM z13 GA2"),
>      CPUDEF_INIT(0x2965, 13, 2, 47, 0x08000000U, "z13s", "IBM z13s GA1"),
>      CPUDEF_INIT(0x3906, 14, 1, 47, 0x08000000U, "z14", "IBM z14 GA1"),
> +    CPUDEF_INIT(0x3907, 14, 1, 47, 0x08000000U, "z14ZR1", "IBM z14 Model ZR1 
> GA1"),
>  };
>  
>  #define QEMU_MAX_CPU_TYPE 0x2827
> 

This is the first time that we have two different EC variants (different
CPU type) with the same HW gen and GA level .

Are they really completely equal (esp. the IBC value? that is used for
model detection) apart from the CPU type?

check_unavailable_features()/arch_query_cpu_model_comparison() will
treat both models as equal (meaning one can run on the other).

arch_query_cpu_model_baseline() might produce a z14ZR1-base when
baselining e.g. a z14 and a z14ZR1 (don't think this is a problem), as
s390_find_cpu_def() will always try to walk as far as possible in the
cpu model definition table.

-- 

Thanks,

David / dhildenb