Re: [PATCH v2 18/20] KVM: S390: Remove PGSTE code from linux/s390 mm

[Steffen Eiden <seiden@linux.ibm.com>]

On Wed, Sep 10, 2025 at 08:07:44PM +0200, Claudio Imbrenda wrote:
> Remove the PGSTE config option.
> Remove all code from linux/s390 mm that involves PGSTEs.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> ---
>  arch/s390/Kconfig               |   3 -
>  arch/s390/include/asm/mmu.h     |  13 -
>  arch/s390/include/asm/page.h    |   4 -
>  arch/s390/include/asm/pgalloc.h |   2 -
>  arch/s390/include/asm/pgtable.h |  99 +---
>  arch/s390/mm/hugetlbpage.c      |  24 -
>  arch/s390/mm/pgalloc.c          |  29 --
>  arch/s390/mm/pgtable.c          | 827 +-------------------------------
>  mm/khugepaged.c                 |   9 -
>  9 files changed, 14 insertions(+), 996 deletions(-)
> 

...

>  #define INIT_MM_CONTEXT(name)						   \
> diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
> index 4e5dbabdf202..b4fb4d7adff4 100644
> --- a/arch/s390/include/asm/page.h
> +++ b/arch/s390/include/asm/page.h
> @@ -78,7 +78,6 @@ static inline void copy_page(void *to, void *from)
>  #ifdef STRICT_MM_TYPECHECKS
>  
>  typedef struct { unsigned long pgprot; } pgprot_t;
> -typedef struct { unsigned long pgste; } pgste_t;
>  typedef struct { unsigned long pte; } pte_t;
>  typedef struct { unsigned long pmd; } pmd_t;
>  typedef struct { unsigned long pud; } pud_t;
> @@ -94,7 +93,6 @@ static __always_inline unsigned long name ## _val(name ## _t name)	\
>  #else /* STRICT_MM_TYPECHECKS */
>  
>  typedef unsigned long pgprot_t;
> -typedef unsigned long pgste_t;
>  typedef unsigned long pte_t;
>  typedef unsigned long pmd_t;
>  typedef unsigned long pud_t;
> @@ -110,7 +108,6 @@ static __always_inline unsigned long name ## _val(name ## _t name)	\
>  #endif /* STRICT_MM_TYPECHECKS */
>  
>  DEFINE_PGVAL_FUNC(pgprot)
> -DEFINE_PGVAL_FUNC(pgste)
>  DEFINE_PGVAL_FUNC(pte)
>  DEFINE_PGVAL_FUNC(pmd)
>  DEFINE_PGVAL_FUNC(pud)
> @@ -120,7 +117,6 @@ DEFINE_PGVAL_FUNC(pgd)
>  typedef pte_t *pgtable_t;
>  
>  #define __pgprot(x)	((pgprot_t) { (x) } )
> -#define __pgste(x)	((pgste_t) { (x) } )
>  #define __pte(x)        ((pte_t) { (x) } )
>  #define __pmd(x)        ((pmd_t) { (x) } )
>  #define __pud(x)	((pud_t) { (x) } )


You missed to remove the PGSTE_*_BIT{,S} and _PGSTE_GPS_* definitions in
arch/s390/include/asm/pgtable.h
(I found them at line 417.. (based on 6.16 with your patches applied))

Or are they kept on purpose? I could not find any usage after your patches.

Steffen