diff --git a/qemu/include/exec/memory.h b/qemu/include/exec/memory.h
index 46dcd2ee..f7c32f16 100644
--- a/qemu/include/exec/memory.h
+++ b/qemu/include/exec/memory.h
@@ -522,8 +522,8 @@ bool memory_region_is_logging(MemoryRegion *mr, uint8_t client);
  * memory_region_get_dirty_log_mask: return the clients for which a
  * memory region is logging writes.
  *
- * Returns a bitmap of clients, which right now will be either 0 or
- * (1 << DIRTY_MEMORY_VGA).
+ * Returns a bitmap of clients, in which the DIRTY_MEMORY_* constants
+ * are the bit indices.
  *
  * @mr: the memory region being queried
  */
diff --git a/qemu/memory.c b/qemu/memory.c
index 97275816..75917302 100644
--- a/qemu/memory.c
+++ b/qemu/memory.c
@@ -1162,6 +1162,7 @@ void memory_region_init_ram(struct uc_struct *uc, MemoryRegion *mr,
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
     mr->ram_addr = qemu_ram_alloc(size, mr, errp);
+    mr->dirty_log_mask = tcg_enabled(uc) ? (1 << DIRTY_MEMORY_CODE) : 0;
 }
 
 void memory_region_init_ram_ptr(struct uc_struct *uc, MemoryRegion *mr,
@@ -1174,6 +1175,7 @@ void memory_region_init_ram_ptr(struct uc_struct *uc, MemoryRegion *mr,
     mr->ram = true;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram_from_ptr;
+    mr->dirty_log_mask = tcg_enabled(uc) ? (1 << DIRTY_MEMORY_CODE) : 0;
 
     /* qemu_ram_alloc_from_ptr cannot fail with ptr != NULL.  */
     assert(ptr != NULL);