3 files changed, 59 insertions, 33 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 9bfdbca14f95..7705180e906d 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -808,6 +808,7 @@ struct gmap {
         spinlock_t guest_table_lock;
         unsigned long *table;
         unsigned long asce;
+        unsigned long asce_end;
         void *private;
         bool pfault_enabled;
 };
@@ -844,7 +845,7 @@ struct gmap_notifier {
         void (*notifier_call)(struct gmap *gmap, unsigned long gaddr);
 };
 
-struct gmap *gmap_alloc(struct mm_struct *mm);
+struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit);
 void gmap_free(struct gmap *gmap);
 void gmap_enable(struct gmap *gmap);
 void gmap_disable(struct gmap *gmap);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 543c24baf1eb..82065dc7948d 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -451,7 +451,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
         if (type & KVM_VM_S390_UCONTROL) {
                 kvm->arch.gmap = NULL;
         } else {
-                kvm->arch.gmap = gmap_alloc(current->mm);
+                kvm->arch.gmap = gmap_alloc(current->mm, -1UL);
                 if (!kvm->arch.gmap)
                         goto out_nogmap;
                 kvm->arch.gmap->private = kvm;
@@ -535,7 +535,7 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
         vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;
         kvm_clear_async_pf_completion_queue(vcpu);
         if (kvm_is_ucontrol(vcpu->kvm)) {
-                vcpu->arch.gmap = gmap_alloc(current->mm);
+                vcpu->arch.gmap = gmap_alloc(current->mm, -1UL);
                 if (!vcpu->arch.gmap)
                         return -ENOMEM;
                 vcpu->arch.gmap->private = vcpu->kvm;
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 74dfd9eaa300..665714b08c0d 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -145,15 +145,34 @@ void crst_table_downgrade(struct mm_struct *mm, unsigned long limit)
 /**
  * gmap_alloc - allocate a guest address space
  * @mm: pointer to the parent mm_struct
+ * @limit: maximum size of the gmap address space
  *
  * Returns a guest address space structure.
  */
-struct gmap *gmap_alloc(struct mm_struct *mm)
+struct gmap *gmap_alloc(struct mm_struct *mm, unsigned long limit)
 {
         struct gmap *gmap;
         struct page *page;
         unsigned long *table;
-
+        unsigned long etype, atype;
+
+        if (limit < (1UL << 31)) {
+                limit = (1UL << 31) - 1;
+                atype = _ASCE_TYPE_SEGMENT;
+                etype = _SEGMENT_ENTRY_EMPTY;
+        } else if (limit < (1UL << 42)) {
+                limit = (1UL << 42) - 1;
+                atype = _ASCE_TYPE_REGION3;
+                etype = _REGION3_ENTRY_EMPTY;
+        } else if (limit < (1UL << 53)) {
+                limit = (1UL << 53) - 1;
+                atype = _ASCE_TYPE_REGION2;
+                etype = _REGION2_ENTRY_EMPTY;
+        } else {
+                limit = -1UL;
+                atype = _ASCE_TYPE_REGION1;
+                etype = _REGION1_ENTRY_EMPTY;
+        }
         gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL);
         if (!gmap)
                 goto out;
@@ -168,10 +187,11 @@ struct gmap *gmap_alloc(struct mm_struct *mm)
         page->index = 0;
         list_add(&page->lru, &gmap->crst_list);
         table = (unsigned long *) page_to_phys(page);
-        crst_table_init(table, _REGION1_ENTRY_EMPTY);
+        crst_table_init(table, etype);
         gmap->table = table;
-        gmap->asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH |
-                     _ASCE_USER_BITS | __pa(table);
+        gmap->asce = atype | _ASCE_TABLE_LENGTH |
+                _ASCE_USER_BITS | __pa(table);
+        gmap->asce_end = limit;
         down_write(&mm->mmap_sem);
         list_add(&gmap->list, &mm->context.gmap_list);
         up_write(&mm->mmap_sem);
@@ -187,8 +207,7 @@ EXPORT_SYMBOL_GPL(gmap_alloc);
 static void gmap_flush_tlb(struct gmap *gmap)
 {
         if (MACHINE_HAS_IDTE)
-                __tlb_flush_asce(gmap->mm, (unsigned long) gmap->table |
-                                 _ASCE_TYPE_REGION1);
+                __tlb_flush_asce(gmap->mm, gmap->asce);
         else
                 __tlb_flush_global();
 }
@@ -227,8 +246,7 @@ void gmap_free(struct gmap *gmap)
 
         /* Flush tlb. */
         if (MACHINE_HAS_IDTE)
-                __tlb_flush_asce(gmap->mm, (unsigned long) gmap->table |
-                                 _ASCE_TYPE_REGION1);
+                __tlb_flush_asce(gmap->mm, gmap->asce);
         else
                 __tlb_flush_global();
 
@@ -394,8 +412,8 @@ int gmap_map_segment(struct gmap *gmap, unsigned long from,
 
         if ((from | to | len) & (PMD_SIZE - 1))
                 return -EINVAL;
-        if (len == 0 || from + len > TASK_MAX_SIZE ||
-            from + len < from || to + len < to)
+        if (len == 0 || from + len < from || to + len < to ||
+            from + len > TASK_MAX_SIZE || to + len > gmap->asce_end)
                 return -EINVAL;
 
         flush = 0;
@@ -501,25 +519,32 @@ int __gmap_link(struct gmap *gmap, unsigned long gaddr, unsigned long vmaddr)
         int rc;
 
         /* Create higher level tables in the gmap page table */
-        table = gmap->table + ((gaddr >> 53) & 0x7ff);
-        if ((*table & _REGION_ENTRY_INVALID) &&
-            gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
-                             gaddr & 0xffe0000000000000))
-                return -ENOMEM;
-        table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
-        table = table + ((gaddr >> 42) & 0x7ff);
-        if ((*table & _REGION_ENTRY_INVALID) &&
-            gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
-                             gaddr & 0xfffffc0000000000))
-                return -ENOMEM;
-        table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
-        table = table + ((gaddr >> 31) & 0x7ff);
-        if ((*table & _REGION_ENTRY_INVALID) &&
-            gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
-                             gaddr & 0xffffffff80000000))
-                return -ENOMEM;
-        table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN);
-        table = table + ((gaddr >> 20) & 0x7ff);
+        table = gmap->table;
+        if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION1) {
+                table += (gaddr >> 53) & 0x7ff;
+                if ((*table & _REGION_ENTRY_INVALID) &&
+                    gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY,
+                                     gaddr & 0xffe0000000000000))
+                        return -ENOMEM;
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+        }
+        if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION2) {
+                table += (gaddr >> 42) & 0x7ff;
+                if ((*table & _REGION_ENTRY_INVALID) &&
+                    gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY,
+                                     gaddr & 0xfffffc0000000000))
+                        return -ENOMEM;
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+        }
+        if ((gmap->asce & _ASCE_TYPE_MASK) >= _ASCE_TYPE_REGION3) {
+                table += (gaddr >> 31) & 0x7ff;
+                if ((*table & _REGION_ENTRY_INVALID) &&
+                    gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY,
+                                     gaddr & 0xffffffff80000000))
+                        return -ENOMEM;
+                table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN);
+        }
+        table += (gaddr >> 20) & 0x7ff;
         /* Walk the parent mm page table */
         mm = gmap->mm;
         pgd = pgd_offset(mm, vmaddr);