Re: [kvm-unit-tests PATCH 2/3] s390x: sclp: Add detection of alternate STFLE facilities

[Janosch Frank <frankja@linux.ibm.com>]

On 2/11/26 15:57, Christoph Schlameuss wrote:
> From: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> 
> Detect availability of alternate STFLE interpretive execution facilities
> 1 and 2.
> Also fix number of unassigned bits in sclp_facilities which wasn't
> adjusted in a prior commit adding entries to sclp_facilities.
> 
> Signed-off-by: Nina Schoetterl-Glausch <nsg@linux.ibm.com>
> Signed-off-by: Christoph Schlameuss <schlameuss@linux.ibm.com>
> ---
>   lib/s390x/sclp.c | 2 ++
>   lib/s390x/sclp.h | 6 +++++-
>   2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/lib/s390x/sclp.c b/lib/s390x/sclp.c
> index 2f902e39e785ff4e139a39be2ffe11b5fa01edc0..7408b813b6396d572d740c19c15175e173fed596 100644
> --- a/lib/s390x/sclp.c
> +++ b/lib/s390x/sclp.c
> @@ -163,8 +163,10 @@ void sclp_facilities_setup(void)
>   	sclp_facilities.has_cmma = sclp_feat_check(116, SCLP_FEAT_116_BIT_CMMA);
>   	sclp_facilities.has_64bscao = sclp_feat_check(116, SCLP_FEAT_116_BIT_64BSCAO);
>   	sclp_facilities.has_esca = sclp_feat_check(116, SCLP_FEAT_116_BIT_ESCA);
> +	sclp_facilities.has_astfleie1 = sclp_feat_check(116, SCLP_FEAT_116_BIT_ASTFLEIE1);
>   	sclp_facilities.has_ibs = sclp_feat_check(117, SCLP_FEAT_117_BIT_IBS);
>   	sclp_facilities.has_pfmfi = sclp_feat_check(117, SCLP_FEAT_117_BIT_PFMFI);
> +	sclp_facilities.has_astfleie2 = sclp_feat_check(139, SCLP_FEAT_139_BIT_ASTFLEIE2);
>   
>   	for (i = 0; i < read_info->entries_cpu; i++, cpu++) {
>   		/*
> diff --git a/lib/s390x/sclp.h b/lib/s390x/sclp.h
> index 22f120d1b7ea7d1c3fe822385d0c689e5b3459fe..91a81c902eaa8ee6b999184aeb8a33633efd1065 100644
> --- a/lib/s390x/sclp.h
> +++ b/lib/s390x/sclp.h
> @@ -129,10 +129,12 @@ struct sclp_facilities {
>   	uint64_t has_cmma : 1;
>   	uint64_t has_64bscao : 1;
>   	uint64_t has_esca : 1;
> +	uint64_t has_astfleie1 : 1;
>   	uint64_t has_kss : 1;
>   	uint64_t has_pfmfi : 1;
>   	uint64_t has_ibs : 1;
> -	uint64_t : 64 - 15;
> +	uint64_t has_astfleie2 : 1;
> +	uint64_t : 64 - 19;
>   };

64 - 17?

I was wondering why the static assert didn't trigger here. Turns out I 
only added it to a feature branch that didn't go upstream yet...

Could you do me a favor and add a patch that introduces the static assert:
_Static_assert(sizeof(struct sclp_facilities) == sizeof(uint64_t));

Then again, why do we pad that at all, it's not a FW struct and I hope 
that we never cast it to u64 and copy it somewhere.

>   
>   /* bit number within a certain byte */
> @@ -143,8 +145,10 @@ struct sclp_facilities {
>   #define SCLP_FEAT_116_BIT_64BSCAO	0
>   #define SCLP_FEAT_116_BIT_CMMA		1
>   #define SCLP_FEAT_116_BIT_ESCA		4
> +#define SCLP_FEAT_116_BIT_ASTFLEIE1	7
>   #define SCLP_FEAT_117_BIT_PFMFI		1
>   #define SCLP_FEAT_117_BIT_IBS		2
> +#define SCLP_FEAT_139_BIT_ASTFLEIE2	1
>   
>   typedef struct ReadInfo {
>   	SCCBHeader h;
>