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s390/mm: return key via pointer in get_guest_storage_key

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Let's just split returning the key and reporting errors. This makes calling
code easier and avoids bugs as happened already.

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
David Hildenbrand
2016-05-09 11:22:34 +02:00
committed by Christian Borntraeger
parent 8d6037a7b4
commit 154c8c19c3
3 changed files with 10 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

3
arch/s390/include/asm/pgtable.h
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@@ -893,7 +893,8 @@ void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long address); bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long address);
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char key, bool nq); unsigned char key, bool nq);
unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr); int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char *key);
/* /*
* Certain architectures need to do special things when PTEs * Certain architectures need to do special things when PTEs

8
arch/s390/kvm/kvm-s390.c
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@@ -1029,7 +1029,6 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
{ {
uint8_t *keys; uint8_t *keys;
uint64_t hva; uint64_t hva;
unsigned long curkey;
int i, r = 0; int i, r = 0;
if (args->flags != 0) if (args->flags != 0)
@@ -1058,12 +1057,9 @@ static long kvm_s390_get_skeys(struct kvm *kvm, struct kvm_s390_skeys *args)
break; break;
} }
curkey = get_guest_storage_key(current->mm, hva); r = get_guest_storage_key(current->mm, hva, &keys[i]);
if (IS_ERR_VALUE(curkey)) { if (r)
r = curkey;
break; break;
}
keys[i] = curkey;
} }
up_read(&current->mm->mmap_sem); up_read(&current->mm->mmap_sem);

12
arch/s390/mm/pgtable.c
View File

@@ -539,9 +539,9 @@ int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
} }
EXPORT_SYMBOL(set_guest_storage_key); EXPORT_SYMBOL(set_guest_storage_key);
unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
unsigned char *key)
{ {
unsigned char key;
spinlock_t *ptl; spinlock_t *ptl;
pgste_t pgste; pgste_t pgste;
pte_t *ptep; pte_t *ptep;
@@ -551,14 +551,14 @@ unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr)
return -EFAULT; return -EFAULT;
pgste = pgste_get_lock(ptep); pgste = pgste_get_lock(ptep);
key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56; *key = (pgste_val(pgste) & (PGSTE_ACC_BITS | PGSTE_FP_BIT)) >> 56;
if (!(pte_val(*ptep) & _PAGE_INVALID)) if (!(pte_val(*ptep) & _PAGE_INVALID))
key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK); *key = page_get_storage_key(pte_val(*ptep) & PAGE_MASK);
/* Reflect guest's logical view, not physical */ /* Reflect guest's logical view, not physical */
key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48; *key |= (pgste_val(pgste) & (PGSTE_GR_BIT | PGSTE_GC_BIT)) >> 48;
pgste_set_unlock(ptep, pgste); pgste_set_unlock(ptep, pgste);
pte_unmap_unlock(ptep, ptl); pte_unmap_unlock(ptep, ptl);
return key; return 0;
} }
EXPORT_SYMBOL(get_guest_storage_key); EXPORT_SYMBOL(get_guest_storage_key);
#endif #endif