It's obviously obsolete.  Do some update.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 accel/kvm/kvm-all.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 524c4ddfbd..b686531586 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -473,13 +473,13 @@ static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
 #define ALIGN(x, y)  (((x)+(y)-1) & ~((y)-1))
 
 /**
- * kvm_physical_sync_dirty_bitmap - Grab dirty bitmap from kernel space
- * This function updates qemu's dirty bitmap using
- * memory_region_set_dirty().  This means all bits are set
- * to dirty.
+ * kvm_physical_sync_dirty_bitmap - Sync dirty bitmap from kernel space
  *
- * @start_add: start of logged region.
- * @end_addr: end of logged region.
+ * This function will first try to fetch dirty bitmap from the kernel,
+ * and then updates qemu's dirty bitmap.
+ *
+ * @kml: the KVM memory listener object
+ * @section: the memory section to sync the dirty bitmap with
  */
 static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
                                           MemoryRegionSection *section)
-- 
2.17.1