KVM: Portability: Move kvm_vcpu_ioctl_get_dirty_log to arch-specific  file

Meanwhile keep the interface in common, and leave as more logic in common
as possible.

Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index b0b6ff2..5f11e6b 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -389,19 +389,14 @@
 	return kvm_set_memory_region(kvm, mem, user_alloc);
 }
 
-/*
- * Get (and clear) the dirty memory log for a memory slot.
- */
-static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-				      struct kvm_dirty_log *log)
+int kvm_get_dirty_log(struct kvm *kvm,
+			struct kvm_dirty_log *log, int *is_dirty)
 {
 	struct kvm_memory_slot *memslot;
 	int r, i;
 	int n;
 	unsigned long any = 0;
 
-	mutex_lock(&kvm->lock);
-
 	r = -EINVAL;
 	if (log->slot >= KVM_MEMORY_SLOTS)
 		goto out;
@@ -420,17 +415,11 @@
 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 		goto out;
 
-	/* If nothing is dirty, don't bother messing with page tables. */
-	if (any) {
-		kvm_mmu_slot_remove_write_access(kvm, log->slot);
-		kvm_flush_remote_tlbs(kvm);
-		memset(memslot->dirty_bitmap, 0, n);
-	}
+	if (any)
+		*is_dirty = 1;
 
 	r = 0;
-
 out:
-	mutex_unlock(&kvm->lock);
 	return r;
 }