KVM: s390: fix task size check

The gmap_map_segment function uses PGDIR_SIZE in the check for the
maximum address in the tasks address space. This incorrectly limits
the amount of memory usable for a kvm guest to 4TB. The correct limit
is (1UL << 53). As the TASK_SIZE has different values (4TB vs 8PB)
dependent on the existance of the fourth page table level, create
a new define 'TASK_MAX_SIZE' for (1UL << 53).

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 6d332487f363..967d0bf1c059 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -335,7 +335,7 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
 
         if ((from | to | len) & (PMD_SIZE - 1))
                 return -EINVAL;
-        if (len == 0 || from + len > PGDIR_SIZE ||
+        if (len == 0 || from + len > TASK_MAX_SIZE ||
             from + len < from || to + len < to)
                 return -EINVAL;