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

Janosch Frank
2021-05-27T14:47:25Z

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"
>