diff options
| author | Jason J. Herne <jjherne@linux.vnet.ibm.com> | 2014-09-23 09:18:57 -0400 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2014-11-28 13:58:48 +0100 |
| commit | 9fcf93b5de063e5cadb95a7bd0130bf73edcd3b5 (patch) | |
| tree | 5c3f3f03d464210dbd82c64b0b04a67eadadda21 /arch/s390 | |
| parent | da00fcbdac1b00bf33b71093047e975cc1f68779 (diff) | |
KVM: S390: Create helper function get_guest_storage_key
Define get_guest_storage_key which can be used to get the value of a guest
storage key. This compliments the functionality provided by the helper function
set_guest_storage_key. Both functions are needed for live migration of s390
guests that use storage keys.
Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/asm/pgalloc.h | 1 | ||||
| -rw-r--r-- | arch/s390/mm/pgtable.c | 39 |
2 files changed, 40 insertions, 0 deletions
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index d39a31c3cdf2..ede2eab42c17 100644 --- a/arch/s390/include/asm/pgalloc.h +++ b/arch/s390/include/asm/pgalloc.h @@ -26,6 +26,7 @@ void page_table_reset_pgste(struct mm_struct *, unsigned long, unsigned long, bool init_skey); int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, unsigned long key, bool nq); +unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr); static inline void clear_table(unsigned long *s, unsigned long val, size_t n) { diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index cfecc241f9a4..0b185857164a 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -980,6 +980,45 @@ retry: } EXPORT_SYMBOL(set_guest_storage_key); +unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr) +{ + spinlock_t *ptl; + pgste_t pgste; + pte_t *ptep; + uint64_t physaddr; + unsigned long key = 0; + + down_read(&mm->mmap_sem); + ptep = get_locked_pte(mm, addr, &ptl); + if (unlikely(!ptep)) { + up_read(&mm->mmap_sem); + return -EFAULT; + } + pgste = pgste_get_lock(ptep); + + if (pte_val(*ptep) & _PAGE_INVALID) { + key |= (pgste_val(pgste) & PGSTE_ACC_BITS) >> 56; + key |= (pgste_val(pgste) & PGSTE_FP_BIT) >> 56; + key |= (pgste_val(pgste) & PGSTE_GR_BIT) >> 48; + key |= (pgste_val(pgste) & PGSTE_GC_BIT) >> 48; + } else { + physaddr = pte_val(*ptep) & PAGE_MASK; + key = page_get_storage_key(physaddr); + + /* Reflect guest's logical view, not physical */ + if (pgste_val(pgste) & PGSTE_GR_BIT) + key |= _PAGE_REFERENCED; + if (pgste_val(pgste) & PGSTE_GC_BIT) + key |= _PAGE_CHANGED; + } + + pgste_set_unlock(ptep, pgste); + pte_unmap_unlock(ptep, ptl); + up_read(&mm->mmap_sem); + return key; +} +EXPORT_SYMBOL(get_guest_storage_key); + #else /* CONFIG_PGSTE */ static inline int page_table_with_pgste(struct page *page) |