Re: [dpdk-dev] [PATCH 4/4] security: add reserved bitfields

[Stephen Hemminger <stephen@networkplumber.org>]

On Sat, 31 Jul 2021 23:43:27 +0530
Akhil Goyal <gakhil@marvell.com> wrote:

> diff --git a/lib/security/rte_security.h b/lib/security/rte_security.h
> index 88d31de0a6..4606425e8d 100644
> --- a/lib/security/rte_security.h
> +++ b/lib/security/rte_security.h
> @@ -181,6 +181,12 @@ struct rte_security_ipsec_sa_options {
>  	 * * 0: Disable per session security statistics collection for this SA.
>  	 */
>  	uint32_t stats : 1;
> +
> +	/** Reserved bit fields for future extension
> +	 *
> +	 * Note: reduce number of bits in reserved_opts for every new option
> +	 */
> +	uint32_t reserved_opts : 24;
>  };
>  
>  /** IPSec security association direction */


You must add a check that these are 0 otherwise they are useless as being
reserved later. You can't assume the old application will leave these bits
as zero.