KVM: introduce id_to_memslot function

Introduce id_to_memslot to get memslot by slot id

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4c2900c5d81d..7b6084999424 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -634,8 +634,9 @@ void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
 {
         if (new) {
                 int id = new->id;
+                struct kvm_memory_slot *old = id_to_memslot(slots, id);
 
-                slots->memslots[id] = *new;
+                *old = *new;
                 if (id >= slots->nmemslots)
                         slots->nmemslots = id + 1;
         }
@@ -681,7 +682,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
         if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
                 goto out;
 
-        memslot = &kvm->memslots->memslots[mem->slot];
+        memslot = id_to_memslot(kvm->memslots, mem->slot);
         base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
         npages = mem->memory_size >> PAGE_SHIFT;
 
@@ -788,12 +789,16 @@ skip_lpage:
 #endif /* not defined CONFIG_S390 */
 
         if (!npages) {
+                struct kvm_memory_slot *slot;
+
                 r = -ENOMEM;
                 slots = kmemdup(kvm->memslots, sizeof(struct kvm_memslots),
                                 GFP_KERNEL);
                 if (!slots)
                         goto out_free;
-                slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID;
+                slot = id_to_memslot(slots, mem->slot);
+                slot->flags |= KVM_MEMSLOT_INVALID;
+
                 update_memslots(slots, NULL);
 
                 old_memslots = kvm->memslots;
@@ -897,7 +902,7 @@ int kvm_get_dirty_log(struct kvm *kvm,
         if (log->slot >= KVM_MEMORY_SLOTS)
                 goto out;
 
-        memslot = &kvm->memslots->memslots[log->slot];
+        memslot = id_to_memslot(kvm->memslots, log->slot);
         r = -ENOENT;
         if (!memslot->dirty_bitmap)
                 goto out;