Re: [RFC v2 bpf-next 3/7] xsk: add usage of XDP features flags

From: Yonghong Song <yhs@meta.com>
To: Lorenzo Bianconi <lorenzo@kernel.org>, bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net,
	andrii@kernel.org, davem@davemloft.net, kuba@kernel.org,
	hawk@kernel.org, pabeni@redhat.com, edumazet@google.com,
	toke@redhat.com, memxor@gmail.com, alardam@gmail.com,
	saeedm@nvidia.com, anthony.l.nguyen@intel.com,
	gospo@broadcom.com, vladimir.oltean@nxp.com, nbd@nbd.name,
	john@phrozen.org, leon@kernel.org, simon.horman@corigine.com,
	aelior@marvell.com, christophe.jaillet@wanadoo.fr,
	ecree.xilinx@gmail.com, mst@redhat.com, bjorn@kernel.org,
	magnus.karlsson@intel.com, maciej.fijalkowski@intel.com,
	intel-wired-lan@lists.osuosl.org, lorenzo.bianconi@redhat.com
Subject: Re: [RFC v2 bpf-next 3/7] xsk: add usage of XDP features flags
Date: Tue, 17 Jan 2023 14:07:08 -0800	[thread overview]
Message-ID: <5e20044c-6057-e5c7-624b-a1373c30fc12@meta.com> (raw)
In-Reply-To: <36956338853442e6d546687678a93470a164ff17.1673710867.git.lorenzo@kernel.org>


On 1/14/23 7:54 AM, Lorenzo Bianconi wrote:
> From: Marek Majtyka <alardam@gmail.com>
> 
> Change necessary condition check for XSK from ndo functions to
> xdp features flags.
> 
> Signed-off-by: Marek Majtyka <alardam@gmail.com>
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> ---
>   net/xdp/xsk_buff_pool.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> index ed6c71826d31..2e6fa082142a 100644
> --- a/net/xdp/xsk_buff_pool.c
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -178,8 +178,7 @@ int xp_assign_dev(struct xsk_buff_pool *pool,
>   		/* For copy-mode, we are done. */
>   		return 0;
>   
> -	if (!netdev->netdev_ops->ndo_bpf ||
> -	    !netdev->netdev_ops->ndo_xsk_wakeup) {
> +	if ((netdev->xdp_features & NETDEV_XDP_ACT_ZC) != NETDEV_XDP_ACT_ZC) {

Maybe:
	if (!(netdev->xdp_features & NETDEV_XDP_ACT_ZC))
?

>   		err = -EOPNOTSUPP;
>   		goto err_unreg_pool;
>   	}