From: "Jason J. Herne" <[email protected]> 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 <[email protected]> Reviewed-by: David Hildenbrand <[email protected]> Signed-off-by: Christian Borntraeger <[email protected]> --- arch/s390/include/asm/pgalloc.h | 1 + arch/s390/mm/pgtable.c | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h index d39a31c..ede2eab 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 cfecc24..0b18585 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) -- 1.9.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
