From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Varghese, Vipin" <vipin.varghese@intel.com>
Subject: Re: [PATCH 07/19] net/ice: support MTU setting
Date: Mon, 26 Nov 2018 03:58:45 +0000
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Cc: "Lu, Wenzhuo" <wenzhuo.lu@intel.com>, "Li, Xiaoyun"
 <xiaoyun.li@intel.com>, "Wu, Jingjing" <jingjing.wu@intel.com>
To: "Yang, Qiming" <qiming.yang@intel.com>, "Lu, Wenzhuo"
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Hi Qiming

> -----Original Message-----
> From: Yang, Qiming
> Sent: Monday, November 26, 2018 9:09 AM
> To: Varghese, Vipin <vipin.varghese@intel.com>; Lu, Wenzhuo
> <wenzhuo.lu@intel.com>; dev@dpdk.org
> Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Li, Xiaoyun <xiaoyun.li@intel.com=
>;
> Wu, Jingjing <jingjing.wu@intel.com>
> Subject: RE: [dpdk-dev] [PATCH 07/19] net/ice: support MTU setting
>=20
> Hi, Vipin
> Not sure understand your question.
> We have no need to configure jumbo frame, because jumbo frame offload wil=
l be
> enable when mtu>1500.

Apologies if the question is not clear. Let me try to explain what I am try=
ing to ask below

>=20
> Qiming
> -----Original Message-----
> From: Varghese, Vipin
> Sent: Friday, November 23, 2018 5:58 PM
> To: Lu, Wenzhuo <wenzhuo.lu@intel.com>; dev@dpdk.org
> Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Yang, Qiming
> <qiming.yang@intel.com>; Li, Xiaoyun <xiaoyun.li@intel.com>; Wu, Jingjing
> <jingjing.wu@intel.com>
> Subject: RE: [dpdk-dev] [PATCH 07/19] net/ice: support MTU setting
>=20
> HI Wenzhou,
>=20
> Following is a thought but not an issue. Can you please let me know your
> thought?
>=20
> <snipped>
>=20
> > +static int
> > +ice_mtu_set(struct rte_eth_dev *dev, uint16_t mtu) {
> > +	struct ice_pf *pf =3D ICE_DEV_PRIVATE_TO_PF(dev->data->dev_private);
> > +	struct rte_eth_dev_data *dev_data =3D pf->dev_data;
> > +	uint32_t frame_size =3D mtu + ETHER_HDR_LEN
> > +			      + ETHER_CRC_LEN + ICE_VLAN_TAG_SIZE;
> > +
> > +	if (rte_eal_process_type() =3D=3D RTE_PROC_SECONDARY)
> > +		return -E_RTE_SECONDARY;
> > +
> > +	/* check if mtu is within the allowed range */
> > +	if ((mtu < ETHER_MIN_MTU) || (frame_size > ICE_FRAME_SIZE_MAX))
> > +		return -EINVAL;
> > +
>=20
> Should we set MTU > 1500 (Jumbo frame) if device is not configured to run=
 with
> jumbo frame? If no, should we check the jumbo config is enabled for the c=
urrent
> device?
>=20

1. If by default JUMBO enabled for this device?
2. There is RX offload which is configured with value 'DEV_RX_OFFLOAD_JUMBO=
_FRAME'. Should this be enabled for supporting JUMBO frames?
3. There is per RX queue offload flag too 'DEV_RX_OFFLOAD_JUMBO_FRAME'. If =
port_conf is set for 'DEV_RX_OFFLOAD_JUMBO_FRAME' but disabled for specific=
 RX queue 'DEV_RX_OFFLOAD_JUMBO_FRAME', what is the JUMBO setting for the d=
evice?

Hence do we need to check 'mtu_set' for whether actually device is configur=
ed for JUMBO processing or not?

> > +	/* mtu setting is forbidden if port is start */
> > +	if (dev_data->dev_started) {
> > +		PMD_DRV_LOG(ERR,
> > +			    "port %d must be stopped before configuration",
> > +			    dev_data->port_id);
> > +		return -EBUSY;
> > +	}
> > +
> > +	if (frame_size > ETHER_MAX_LEN)
> > +		dev_data->dev_conf.rxmode.offloads |=3D
> > +			DEV_RX_OFFLOAD_JUMBO_FRAME;
> > +	else
> > +		dev_data->dev_conf.rxmode.offloads &=3D
> > +			~DEV_RX_OFFLOAD_JUMBO_FRAME;
> > +
> > +	dev_data->dev_conf.rxmode.max_rx_pkt_len =3D frame_size;
> > +
> > +	return 0;
> > +}
> > --
> > 1.9.3