Re: [kvm-unit-tests PATCH v4 3/7] s390x: lib: fix pgtable.h

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

On 5/26/21 3:42 PM, Claudio Imbrenda wrote:
> Fix pgtable.h:
> 
> * SEGMENT_ENTRY_SFAA had one extra bit set
> * pmd entries don't have a length field
> * ipte does not need to clear the lower bits
>  - clearing the 12 lower bits is technically incorrect, as page tables are
>    architecturally aligned to 11 bit addresses (even though the unit tests
>    allocate always one full page)
> * region table entries should use REGION_ENTRY_TL instead of *_TABLE_LENGTH
>  - *_TABLE_LENGTH need to stay, because they should be used for ASCEs
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>

> ---
>  lib/s390x/asm/pgtable.h | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/s390x/asm/pgtable.h b/lib/s390x/asm/pgtable.h
> index 277f3480..1a21f175 100644
> --- a/lib/s390x/asm/pgtable.h
> +++ b/lib/s390x/asm/pgtable.h
> @@ -60,7 +60,7 @@
>  #define SEGMENT_SHIFT			20
>  
>  #define SEGMENT_ENTRY_ORIGIN		0xfffffffffffff800UL
> -#define SEGMENT_ENTRY_SFAA		0xfffffffffff80000UL
> +#define SEGMENT_ENTRY_SFAA		0xfffffffffff00000UL
>  #define SEGMENT_ENTRY_AV		0x0000000000010000UL
>  #define SEGMENT_ENTRY_ACC		0x000000000000f000UL
>  #define SEGMENT_ENTRY_F			0x0000000000000800UL
> @@ -143,7 +143,7 @@ static inline p4d_t *p4d_alloc(pgd_t *pgd, unsigned long addr)
>  	if (pgd_none(*pgd)) {
>  		p4d_t *p4d = p4d_alloc_one();
>  		pgd_val(*pgd) = __pa(p4d) | REGION_ENTRY_TT_REGION1 |
> -				REGION_TABLE_LENGTH;
> +				REGION_ENTRY_TL;
>  	}
>  	return p4d_offset(pgd, addr);
>  }
> @@ -163,7 +163,7 @@ static inline pud_t *pud_alloc(p4d_t *p4d, unsigned long addr)
>  	if (p4d_none(*p4d)) {
>  		pud_t *pud = pud_alloc_one();
>  		p4d_val(*p4d) = __pa(pud) | REGION_ENTRY_TT_REGION2 |
> -				REGION_TABLE_LENGTH;
> +				REGION_ENTRY_TL;
>  	}
>  	return pud_offset(p4d, addr);
>  }
> @@ -183,7 +183,7 @@ static inline pmd_t *pmd_alloc(pud_t *pud, unsigned long addr)
>  	if (pud_none(*pud)) {
>  		pmd_t *pmd = pmd_alloc_one();
>  		pud_val(*pud) = __pa(pmd) | REGION_ENTRY_TT_REGION3 |
> -				REGION_TABLE_LENGTH;
> +				REGION_ENTRY_TL;
>  	}
>  	return pmd_offset(pud, addr);
>  }
> @@ -202,15 +202,14 @@ static inline pte_t *pte_alloc(pmd_t *pmd, unsigned long addr)
>  {
>  	if (pmd_none(*pmd)) {
>  		pte_t *pte = pte_alloc_one();
> -		pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT |
> -				SEGMENT_TABLE_LENGTH;
> +		pmd_val(*pmd) = __pa(pte) | SEGMENT_ENTRY_TT_SEGMENT;
>  	}
>  	return pte_offset(pmd, addr);
>  }
>  
>  static inline void ipte(unsigned long vaddr, pteval_t *p_pte)
>  {
> -	unsigned long table_origin = (unsigned long)p_pte & PAGE_MASK;
> +	unsigned long table_origin = (unsigned long)p_pte;
>  
>  	asm volatile(
>  		"	ipte %0,%1\n"
>