[dpdk-dev] [PATCH 2/3] ethdev: fail if Tx queue offload is not supported at all

[Shahaf Shuler]

--Shahaf


> -----Original Message-----
> From: Andrew Rybchenko <arybchenko at solarflare.com>
> Sent: Friday, May 11, 2018 7:26 PM
> To: dev at dpdk.org
> Cc: Ferruh Yigit <ferruh.yigit at intel.com>; Thomas Monjalon
> <thomas at monjalon.net>; Shahaf Shuler <shahafs at mellanox.com>; Wei Dai
> <wei.dai at intel.com>
> Subject: [PATCH 2/3] ethdev: fail if Tx queue offload is not supported at all
> 
> Do not allow to request unsupported Tx offload since all checks are removed
> from PMDs because of consistency check in ethdev.
> Otherwise application may rely on offload which is not actually supported
> and send traffic with, for example, wrong checksums, truncated packets or
> packets with garbage.
> 
> Fixes: d04dd6d4ed67 ("ethdev: new Rx/Tx offloads API")
> 
> Signed-off-by: Andrew Rybchenko <arybchenko at solarflare.com>
> ---
>  lib/librte_ethdev/rte_ethdev.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
> index dd36e6270..60577efcf 100644
> --- a/lib/librte_ethdev/rte_ethdev.c
> +++ b/lib/librte_ethdev/rte_ethdev.c
> @@ -1744,6 +1744,16 @@ rte_eth_tx_queue_setup(uint16_t port_id,
> uint16_t tx_queue_id,
>  				local_conf.offloads,
>  				dev_info.tx_queue_offload_capa,
>  				__func__);
> +		/*
> +		 * Applications which are not converted yet to the new
> +		 * Tx offload API may request device level offloads on
> +		 * queue level (and nothing is requested on device level).
> +		 * However, if the offload is not supported at all Tx
> +		 * queue setup must fail.
> +		 */
> +		if ((local_conf.offloads & dev_info.tx_offload_capa) !=
> +		    local_conf.offloads)
> +			return -EINVAL;

Not converted application doesn't have a clue what are per-queue offloads, and this is the error they will get when the Tx queue configuration will fail.

How about using ETH_TXQ_FLAGS_IGNORE flag, which explicitly says "application converted to the new Tx offloads API". and have 2 different checks:
1. for converted application the already exist check[1] with the related error.
2. for not converted application your check with a related error. 


[1]
if ((local_conf.offloads & dev_info.tx_queue_offload_capa) !=
     local_conf.offloads) {                                  

>  	}
> 
>  	return eth_err(port_id, (*dev->dev_ops->tx_queue_setup)(dev,
> --
> 2.17.0