Re: [PATCH net-next v6] net: openvswitch: IPv6: Add IPv6 extension header support

[Jakub Kicinski]

On Tue, 28 Sep 2021 12:47:27 -0700 Toms Atteka wrote:
> diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
> index a87b44cd5590..dc6eb5f6399f 100644
> --- a/include/uapi/linux/openvswitch.h
> +++ b/include/uapi/linux/openvswitch.h
> @@ -346,6 +346,13 @@ enum ovs_key_attr {
>  #ifdef __KERNEL__
>  	OVS_KEY_ATTR_TUNNEL_INFO,  /* struct ip_tunnel_info */
>  #endif
> +
> +#ifndef __KERNEL__

#else

> +	PADDING,  /* Padding so kernel and non kernel field count would match */

The name PADDING seems rather risky, collisions will be likely.
OVS_KEY_ATTR_PADDING maybe?

But maybe we don't need to define this special value and bake it into
the uAPI, why can't we add something like this to the kernel header
(i.e. include/linux/openvswitch.h):

/* Insert a kernel only KEY_ATTR */
#define OVS_KEY_ATTR_TUNNEL_INFO	__OVS_KEY_ATTR_MAX
#undef OVS_KEY_ATTR_MAX
#define OVS_KEY_ATTR_MAX		__OVS_KEY_ATTR_MAX

> +#endif