KVM: introduce update_memslots function

Introduce update_memslots to update slot which will be update to
kvm->memslots

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

3 files changed, 17 insertions, 8 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index af546b768ffd..917a287d21c8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3546,7 +3546,7 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
                 memslot = &slots->memslots[log->slot];
                 memslot->dirty_bitmap = dirty_bitmap;
                 memslot->nr_dirty_pages = 0;
-                slots->generation++;
+                update_memslots(slots, NULL);
 
                 old_slots = kvm->memslots;
                 rcu_assign_pointer(kvm->memslots, slots);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 924df0d7ac5f..23f795c66220 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -320,6 +320,7 @@ void kvm_exit(void);
 
 void kvm_get_kvm(struct kvm *kvm);
 void kvm_put_kvm(struct kvm *kvm);
+void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new);
 
 static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
 {
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9ad94c9996e7..b5ed7770ced3 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -630,6 +630,19 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
 }
 #endif /* !CONFIG_S390 */
 
+void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
+{
+        if (new) {
+                int id = new->id;
+
+                slots->memslots[id] = *new;
+                if (id >= slots->nmemslots)
+                        slots->nmemslots = id + 1;
+        }
+
+        slots->generation++;
+}
+
 /*
  * Allocate some memory and give it an address in the guest physical address
  * space.
@@ -780,10 +793,8 @@ skip_lpage:
                                 GFP_KERNEL);
                 if (!slots)
                         goto out_free;
-                if (mem->slot >= slots->nmemslots)
-                        slots->nmemslots = mem->slot + 1;
-                slots->generation++;
                 slots->memslots[mem->slot].flags |= KVM_MEMSLOT_INVALID;
+                update_memslots(slots, NULL);
 
                 old_memslots = kvm->memslots;
                 rcu_assign_pointer(kvm->memslots, slots);
@@ -815,9 +826,6 @@ skip_lpage:
                         GFP_KERNEL);
         if (!slots)
                 goto out_free;
-        if (mem->slot >= slots->nmemslots)
-                slots->nmemslots = mem->slot + 1;
-        slots->generation++;
 
         /* actual memory is freed via old in kvm_free_physmem_slot below */
         if (!npages) {
@@ -827,7 +835,7 @@ skip_lpage:
                         new.lpage_info[i] = NULL;
         }
 
-        slots->memslots[mem->slot] = new;
+        update_memslots(slots, &new);
         old_memslots = kvm->memslots;
         rcu_assign_pointer(kvm->memslots, slots);
         synchronize_srcu_expedited(&kvm->srcu);