Re: [PATCH] net/fm10k: fix secondary process crash

["Chen, Jing D" <jing.d.chen@intel.com>]

> -----Original Message-----
> From: Wang, Xiao W
> Sent: Tuesday, March 28, 2017 11:59 AM
> To: Chen, Jing D <jing.d.chen@intel.com>
> Cc: dev@dpdk.org; Wang, Xiao W <xiao.w.wang@intel.com>; stable@dpdk.org
> Subject: [PATCH] net/fm10k: fix secondary process crash
> 
> If the primary process has initialized all the queues to vector pmd mode, the
> secondary process should not use scalar code path, because the per queue data
> structures haven't been prepared for that, e.g. txq->ops is for vector Tx rather
> than scalar Tx.
> 
> Fixes: a6ce64a97520 ("fm10k: introduce vector driver")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
> ---
>  drivers/net/fm10k/fm10k_ethdev.c | 28 ++++++++++++++++++++++++++--
>  1 file changed, 26 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/fm10k/fm10k_ethdev.c
> b/drivers/net/fm10k/fm10k_ethdev.c
> index 388f929..680d617 100644
> --- a/drivers/net/fm10k/fm10k_ethdev.c
> +++ b/drivers/net/fm10k/fm10k_ethdev.c
> @@ -2750,6 +2750,21 @@ static void __attribute__((cold))
>  	int use_sse = 1;
>  	uint16_t tx_ftag_en = 0;
> 
> +	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> +		/* primary process has set the ftag flag and txq_flags */
> +		txq = dev->data->tx_queues[0];
> +		if (fm10k_tx_vec_condition_check(txq)) {
> +			dev->tx_pkt_burst = fm10k_xmit_pkts;
> +			dev->tx_pkt_prepare = fm10k_prep_pkts;
> +			PMD_INIT_LOG(DEBUG, "Use regular Tx func");
> +		} else {
> +			PMD_INIT_LOG(DEBUG, "Use vector Tx func");
> +			dev->tx_pkt_burst = fm10k_xmit_pkts_vec;
> +			dev->tx_pkt_prepare = NULL;
> +		}
> +		return;
> +	}
> +

Why we need to check process type? What would happen if no changes made here?

>  	if (fm10k_check_ftag(dev->device->devargs))
>  		tx_ftag_en = 1;
> 
> @@ -2810,6 +2825,9 @@ static void __attribute__((cold))
>  	else
>  		PMD_INIT_LOG(DEBUG, "Use regular Rx func");
> 
> +	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> +		return;
> +
>  	for (i = 0; i < dev->data->nb_rx_queues; i++) {
>  		struct fm10k_rx_queue *rxq = dev->data->rx_queues[i];
> 
> @@ -2856,9 +2874,15 @@ static void __attribute__((cold))
>  	dev->tx_pkt_burst = &fm10k_xmit_pkts;
>  	dev->tx_pkt_prepare = &fm10k_prep_pkts;
> 
> -	/* only initialize in the primary process */
> -	if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> +	/*
> +	 * Primary process does the whole initialization, for secondary
> +	 * processes, we just select the same Rx and Tx function as primary.
> +	 */
> +	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
> +		fm10k_set_rx_function(dev);
> +		fm10k_set_tx_function(dev);
>  		return 0;
> +	}
> 
>  	rte_eth_copy_pci_info(dev, pdev);
>  	dev->data->dev_flags |= RTE_ETH_DEV_DETACHABLE;
> --
> 1.8.3.1