KVM: Simplify ifndef conditional usage in __kvm_set_memory_region()

Narrow down the controlled text inside the conditional so that it will
include lpage_info and rmap stuff only.

For this we change the way we check whether the slot is being created
from "if (npages && !new.rmap)" to "if (npages && !old.npages)".

We also stop checking if lpage_info is NULL when we create lpage_info
because we do it from inside the slot creation code block.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 8 insertions, 21 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 7adaa2063415..a30447c5eb4a 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -616,7 +616,6 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
         return 0;
 }
 
-#ifndef CONFIG_S390
 /*
  * Allocation size is twice as large as the actual dirty bitmap size.
  * This makes it possible to do double buffering: see x86's
@@ -624,6 +623,7 @@ static int kvm_vm_release(struct inode *inode, struct file *filp)
  */
 static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 {
+#ifndef CONFIG_S390
         unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
 
         if (dirty_bytes > PAGE_SIZE)
@@ -636,9 +636,9 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 
         memslot->dirty_bitmap_head = memslot->dirty_bitmap;
         memslot->nr_dirty_pages = 0;
+#endif /* !CONFIG_S390 */
         return 0;
 }
-#endif /* !CONFIG_S390 */
 
 static int cmp_memslot(const void *slot1, const void *slot2)
 {
@@ -695,9 +695,6 @@ static int create_lpage_info(struct kvm_memory_slot *slot, unsigned long npages)
                 int lpages;
                 int level = i + 2;
 
-                if (slot->lpage_info[i])
-                        continue;
-
                 lpages = gfn_to_index(slot->base_gfn + npages - 1,
                                       slot->base_gfn, level) + 1;
 
@@ -815,23 +812,18 @@ int __kvm_set_memory_region(struct kvm *kvm,
         r = -ENOMEM;
 
         /* Allocate if a slot is being created */
+        if (npages && !old.npages) {
+                new.user_alloc = user_alloc;
+                new.userspace_addr = mem->userspace_addr;
 #ifndef CONFIG_S390
-        if (npages && !new.rmap) {
                 new.rmap = vzalloc(npages * sizeof(*new.rmap));
-
                 if (!new.rmap)
                         goto out_free;
 
-                new.user_alloc = user_alloc;
-                new.userspace_addr = mem->userspace_addr;
+                if (create_lpage_info(&new, npages))
+                        goto out_free;
+#endif /* not defined CONFIG_S390 */
         }
-        if (!npages)
-                goto skip_lpage;
-
-        if (create_lpage_info(&new, npages))
-                goto out_free;
-
-skip_lpage:
 
         /* Allocate page dirty bitmap if needed */
         if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
@@ -839,11 +831,6 @@ skip_lpage:
                         goto out_free;
                 /* destroy any largepage mappings for dirty tracking */
         }
-#else  /* not defined CONFIG_S390 */
-        new.user_alloc = user_alloc;
-        if (user_alloc)
-                new.userspace_addr = mem->userspace_addr;
-#endif /* not defined CONFIG_S390 */
 
         if (!npages) {
                 struct kvm_memory_slot *slot;