func: static int ram_block_enable_notify(const char *block_name, void *host_addr,
  
                                     ram_addr_t offset, ram_addr_t length,
  
                                     void *opaque)
  
  {
  
      MigrationIncomingState *mis = opaque;
  
      struct uffdio_register reg_struct;
  
  
  
      reg_struct.range.start = (uintptr_t)host_addr;
  
      reg_struct.range.len = length;
  
      reg_struct.mode = UFFDIO_REGISTER_MODE_MISSING;
  
  
  
      /* Now tell our userfault_fd that it's responsible for this area */
  
      if (ioctl(mis->userfault_fd, UFFDIO_REGISTER, &reg_struct)) {
  
          error_report("%s userfault register: %s", __func__, strerror(errno));
  
  
  
  
  
  
  
  
  
      return 0;
  