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s390/uv: Convert uv_convert_owned_from_secure() to uv_convert_from_secure_(folio|pte)()

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Let's do the same as we did for uv_destroy_(folio|pte)() and
have the following variants:

(1) uv_convert_from_secure(): "low level" helper that operates on paddr
and does not mess with folios.

(2) uv_convert_from_secure_folio(): Consumes a folio to which we hold a
reference.

(3) uv_convert_from_secure_pte(): Consumes a PTE that holds a reference
through the mapping.

Unfortunately we need uv_convert_from_secure_pte(), because pfn_folio()
and friends are not available in pgtable.h.

Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20240508182955.358628-9-david@redhat.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
David Hildenbrand 2024-05-08 20:29:53 +02:00 committed by Alexander Gordeev
parent 7063150650
commit 7d17143469
3 changed files with 18 additions and 10 deletions
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6
arch/s390/include/asm/pgtable.h
View File

@ -1167,7 +1167,7 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
/* At this point the reference through the mapping is still present */
if (mm_is_protected(mm) && pte_present(res))
uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
uv_convert_from_secure_pte(res);
return res;
}
@ -1185,7 +1185,7 @@ static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
res = ptep_xchg_direct(vma->vm_mm, addr, ptep, __pte(_PAGE_INVALID));
/* At this point the reference through the mapping is still present */
if (mm_is_protected(vma->vm_mm) && pte_present(res))
uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
uv_convert_from_secure_pte(res);
return res;
}
@ -1224,7 +1224,7 @@ static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
* if this is not a mm teardown, the slower export is used as
* fallback instead.
*/
uv_convert_owned_from_secure(pte_val(res) & PAGE_MASK);
uv_convert_from_secure_pte(res);
return res;
}

4
arch/s390/include/asm/uv.h
View File

@ -485,7 +485,7 @@ int gmap_make_secure(struct gmap *gmap, unsigned long gaddr, void *uvcb);
int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr);
int uv_destroy_folio(struct folio *folio);
int uv_destroy_pte(pte_t pte);
int uv_convert_owned_from_secure(unsigned long paddr);
int uv_convert_from_secure_pte(pte_t pte);
int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr);
void setup_uv(void);
@ -508,7 +508,7 @@ static inline int uv_destroy_pte(pte_t pte)
return 0;
}
static inline int uv_convert_owned_from_secure(unsigned long paddr)
static inline int uv_convert_from_secure_pte(pte_t pte)
{
return 0;
}

18
arch/s390/kernel/uv.c
View File

@ -178,11 +178,10 @@ static int uv_convert_from_secure(unsigned long paddr)
}
/*
* The caller must already hold a reference to the page
* The caller must already hold a reference to the folio.
*/
int uv_convert_owned_from_secure(unsigned long paddr)
static int uv_convert_from_secure_folio(struct folio *folio)
{
struct folio *folio = phys_to_folio(paddr);
int rc;
/* See gmap_make_secure(): large folios cannot be secure */
@ -190,13 +189,22 @@ int uv_convert_owned_from_secure(unsigned long paddr)
return 0;
folio_get(folio);
rc = uv_convert_from_secure(paddr);
rc = uv_convert_from_secure(folio_to_phys(folio));
if (!rc)
clear_bit(PG_arch_1, &folio->flags);
folio_put(folio);
return rc;
}
/*
* The present PTE still indirectly holds a folio reference through the mapping.
*/
int uv_convert_from_secure_pte(pte_t pte)
{
VM_WARN_ON(!pte_present(pte));
return uv_convert_from_secure_folio(pfn_folio(pte_pfn(pte)));
}
/*
* Calculate the expected ref_count for a folio that would otherwise have no
* further pins. This was cribbed from similar functions in other places in
@ -481,7 +489,7 @@ int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
* we instead try to export the page.
*/
if (rc)
rc = uv_convert_owned_from_secure(page_to_phys(page));
rc = uv_convert_from_secure_folio(folio);
folio_put(folio);
out:
mmap_read_unlock(gmap->mm);