[PATCH v7 18/21] net/cpfl: add HW statistics

[Liu, Mingxia]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit at amd.com>
> Sent: Tuesday, February 28, 2023 5:52 AM
> To: Liu, Mingxia <mingxia.liu at intel.com>; dev at dpdk.org; Xing, Beilei
> <beilei.xing at intel.com>; Zhang, Yuying <yuying.zhang at intel.com>
> Subject: Re: [PATCH v7 18/21] net/cpfl: add HW statistics
> 
> On 2/16/2023 12:30 AM, Mingxia Liu wrote:
> > This patch add hardware packets/bytes statistics.
> >
> > Signed-off-by: Mingxia Liu <mingxia.liu at intel.com>
> 
> <...>
> 
> > +static int
> > +cpfl_dev_stats_get(struct rte_eth_dev *dev, struct rte_eth_stats
> > +*stats) {
> > +	struct idpf_vport *vport =
> > +		(struct idpf_vport *)dev->data->dev_private;
> > +	struct virtchnl2_vport_stats *pstats = NULL;
> > +	int ret;
> > +
> > +	ret = idpf_vc_stats_query(vport, &pstats);
> > +	if (ret == 0) {
> > +		uint8_t crc_stats_len = (dev->data-
> >dev_conf.rxmode.offloads &
> > +					 RTE_ETH_RX_OFFLOAD_KEEP_CRC) ?
> 0 :
> > +					 RTE_ETHER_CRC_LEN;
> > +
> > +		idpf_vport_stats_update(&vport->eth_stats_offset, pstats);
> > +		stats->ipackets = pstats->rx_unicast + pstats->rx_multicast +
> > +				pstats->rx_broadcast - pstats->rx_discards;
> > +		stats->opackets = pstats->tx_broadcast + pstats->tx_multicast
> +
> > +						pstats->tx_unicast;
> > +		stats->imissed = pstats->rx_discards;
> > +		stats->oerrors = pstats->tx_errors + pstats->tx_discards;
> > +		stats->ibytes = pstats->rx_bytes;
> > +		stats->ibytes -= stats->ipackets * crc_stats_len;
> > +		stats->obytes = pstats->tx_bytes;
> > +
> > +		dev->data->rx_mbuf_alloc_failed =
> > +cpfl_get_mbuf_alloc_failed_stats(dev);
> 
> 'dev->data->rx_mbuf_alloc_failed' is also used by telemetry, updating here
> only in stats_get() will make it wrong for telemetry.
> 
> Is it possible to update 'dev->data->rx_mbuf_alloc_failed' whenever alloc
> failed? (alongside 'rxq->rx_stats.mbuf_alloc_failed').
[Liu, Mingxia] As I know, rte_eth_dev_data is not a public structure provided to user, user need to access through rte_ethdev APIs.
Because we already put rx and tx burst func to common/idpf which has no dependcy with ethdev lib. If I update "dev->data->rx_mbuf_alloc_failed" 
when allocate mbuf fails, it will break the design of our common/idpf interface to net/cpfl or net.idpf.

And I didn't find any reference of 'dev->data->rx_mbuf_alloc_failed' in lib code.