[dpdk-dev] [RFC PATCH 4/4] ethdev: add helpers to move to the new offloads API

Ananyev, Konstantin konstantin.ananyev at intel.com
Mon Aug 28 16:12:13 CEST 2017



> -----Original Message-----
> From: Shahaf Shuler [mailto:shahafs at mellanox.com]
> Sent: Wednesday, August 23, 2017 2:13 PM
> To: Ananyev, Konstantin <konstantin.ananyev at intel.com>; dev at dpdk.org
> Subject: RE: [dpdk-dev] [RFC PATCH 4/4] ethdev: add helpers to move to the new offloads API
> 
> Wednesday, August 23, 2017 3:29 PM, Ananyev, Konstantin:
> >
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Shahaf Shuler
> > > Sent: Monday, August 7, 2017 1:55 PM
> > > To: dev at dpdk.org
> > > Subject: [dpdk-dev] [RFC PATCH 4/4] ethdev: add helpers to move to the
> > > new offloads API
> > >
> > > A new offloads API was introduced by commits:
> > >
> > > commit 8b07fcae6061 ("ethdev: introduce Tx queue offloads API") commit
> > > c6504557763e ("ethdev: introduce Rx queue offloads API")
> > >
> > > In order to enable PMDs to support only one of the APIs, and
> > > applications to avoid branching according to the underlying device a
> > > copy functions to/from the old/new APIs were added.
> > >
> > > Signed-off-by: Shahaf Shuler <shahafs at mellanox.com>
> > > ---
> > >  lib/librte_ether/rte_ethdev.c | 140
> > > +++++++++++++++++++++++++++++++++++++
> > >  1 file changed, 140 insertions(+)
> > >
> > > diff --git a/lib/librte_ether/rte_ethdev.c
> > > b/lib/librte_ether/rte_ethdev.c index f73307e99..2b4a28c97 100644
> > > --- a/lib/librte_ether/rte_ethdev.c
> > > +++ b/lib/librte_ether/rte_ethdev.c
> > > @@ -1003,6 +1003,63 @@ rte_eth_dev_close(uint8_t port_id)
> > >  	dev->data->tx_queues = NULL;
> > >  }
> > >
> > > +/**
> > > + * A copy function from rxmode offloads API to rte_eth_rxq_conf
> > > + * offloads API, to enable PMDs to support only one of the APIs.
> > > + */
> > > +static void
> > > +rte_eth_copy_rxmode_offloads(struct rte_eth_rxmode *rxmode,
> > > +			     struct rte_eth_rxq_conf *rxq_conf) {
> > > +	if (rxmode->header_split == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_HEADER_SPLIT;
> > > +	if (rxmode->hw_ip_checksum == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_CHECKSUM;
> > > +	if (rxmode->hw_vlan_filter == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_VLAN_FILTER;
> > > +	if (rxmode->hw_vlan_strip == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_VLAN_STRIP;
> > > +	if (rxmode->hw_vlan_extend == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_VLAN_EXTEND;
> > > +	if (rxmode->jumbo_frame == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_JUMBO_FRAME;
> > > +	if (rxmode->hw_strip_crc == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_CRC_STRIP;
> > > +	if (rxmode->enable_scatter == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_SCATTER;
> > > +	if (rxmode->enable_lro == 1)
> > > +		rxq_conf->offloads |= DEV_RX_OFFLOAD_LRO; }
> > > +
> > > +/**
> > > + * A copy function between rte_eth_rxq_conf offloads API to rxmode
> > > + * offloads API, to enable application to be agnostic to the PMD
> > > +supported
> > > + * offload API.
> > > + */
> > > +static void
> > > +rte_eth_copy_rxq_offloads(struct rte_eth_rxmode *rxmode,
> > > +			  struct rte_eth_rxq_conf *rxq_conf) {
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_HEADER_SPLIT)
> > > +		rxmode->header_split = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_CHECKSUM)
> > > +		rxmode->hw_ip_checksum = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_VLAN_FILTER)
> > > +		rxmode->hw_vlan_filter = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_VLAN_STRIP)
> > > +		rxmode->hw_vlan_strip = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_VLAN_EXTEND)
> > > +		rxmode->hw_vlan_extend = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_JUMBO_FRAME)
> > > +		rxmode->jumbo_frame = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_CRC_STRIP)
> > > +		rxmode->hw_strip_crc = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_SCATTER)
> > > +		rxmode->enable_scatter = 1;
> > > +	if (rxq_conf->offloads & DEV_RX_OFFLOAD_LRO)
> > > +		rxmode->enable_lro = 1;
> > > +}
> > > +
> > >  int
> > >  rte_eth_rx_queue_setup(uint8_t port_id, uint16_t rx_queue_id,
> > >  		       uint16_t nb_rx_desc, unsigned int socket_id, @@ -1083,6
> > > +1140,37 @@ rte_eth_rx_queue_setup(uint8_t port_id, uint16_t
> > rx_queue_id,
> > >  	if (rx_conf == NULL)
> > >  		rx_conf = &dev_info.default_rxconf;
> > >
> > > +	if ((dev->data->dev_flags & RTE_ETH_DEV_RXQ_OFFLOAD) &&
> > > +	    (dev->data->dev_conf.rxmode.ignore == 0)) {
> > > +		rte_eth_copy_rxmode_offloads(&dev->data-
> > >dev_conf.rxmode,
> > > +					     rx_conf);
> > > +	} else if ((!(dev->data->dev_flags & RTE_ETH_DEV_RXQ_OFFLOAD))
> > &&
> > > +		   (dev->data->dev_conf.rxmode.ignore == 1)) {
> > > +		int ret;
> > > +		struct rte_eth_rxmode rxmode;
> > > +
> > > +		rte_eth_copy_rxq_offloads(&rxmode, rx_conf);
> > > +		if (memcmp(&rxmode, &dev->data->dev_conf.rxmode,
> > > +			   sizeof(rxmode))) {
> > > +			/*
> > > +			 * device which work with rxmode offloads API
> > requires
> > > +			 * a re-configuration in order to apply the new
> > offloads
> > > +			 * configuration.
> > > +			 */
> > > +			dev->data->dev_conf.rxmode = rxmode;
> > > +			ret = rte_eth_dev_configure(port_id,
> > > +					dev->data->nb_rx_queues,
> > > +					dev->data->nb_tx_queues,
> > > +					&dev->data->dev_conf);
> >
> >
> > Hmm, and why we would need to reconfigure our device in the middle of rx
> > queue setup?
> 
> The reason is the old Rx offloads API is configured on device configure.
> This if section is for applications which already moved to the new offload API however the underlying PMD still uses the old one.

Ok, but as I remember, right now the initialization order is pretty strict:
rx_queue_setup() has to be always called after dev_configure().
One of the reasons for that: rx_queue_setup() might change fileds inside  dev->data->dev_private.
Second call for dev_configure() will void these changes and some of rxq config information will be lost.
So I think we should avoid calling dev_configure() inside rx_queue_setup().

My preference still would be to force all PMDs to move to the new version of rx_queue_setup() first.
I think it would be much more error prone then supporting two flavors of PMD config
and will allow us to catch errors early - in case this new scheme doesn't work by some PMD for any reason.   

Also it seems that you  forgot to:
struct rte_eth_rxmode rxmode  = dev->data->dev_conf.rxmode;

Konstantin


> 
> >
> > > +			if (ret < 0) {
> > > +				RTE_PMD_DEBUG_TRACE(
> > > +					"unable to re-configure port %d "
> > > +					"in order to apply rxq offloads "
> > > +					"configuration\n", port_id);
> > > +			}
> > > +		}
> > > +	}
> > > +
> > >  	ret = (*dev->dev_ops->rx_queue_setup)(dev, rx_queue_id,
> > nb_rx_desc,
> > >  					      socket_id, rx_conf, mp);
> >
> > BTW, I don't see changes in any PMD for new offload flags?
> > Is it because it is just a n RFC and full patch would contain such changes?
> 
> Yes this is because this is an RFC.
> 
> The full patch I intend will move all examples and testpmd to the new offloads API.
> In addition it will include the mlx5 PMD support for the new offloads API.
> 
> As I said on previous mail, I believe that the work to move the different PMDs to the new API should be done by their developers or
> maintainers.
> 
> >
> >
> > >  	if (!ret) {
> > > @@ -1094,6 +1182,51 @@ rte_eth_rx_queue_setup(uint8_t port_id,
> > uint16_t rx_queue_id,
> > >  	return ret;
> > >  }
> > >
> > > +/**
> > > + * A copy function from txq_flags to rte_eth_txq_conf offloads API,
> > > + * to enable PMDs to support only one of the APIs.
> > > + */
> > > +static void
> > > +rte_eth_copy_txq_flags(struct rte_eth_txq_conf *txq_conf) {
> > > +	uint32_t txq_flags = txq_conf->txq_flags
> > > +	uint64_t *offloads = &txq_conf->offloads;
> > > +
> > > +	if (!(txq_flags & ETH_TXQ_FLAGS_NOMULTSEGS))
> > > +		*offloads |= DEV_TX_OFFLOAD_MULTI_SEGS;
> > > +	if (!(txq_flags & ETH_TXQ_FLAGS_NOVLANOFFL))
> > > +		*offloads |= DEV_TX_OFFLOAD_VLAN_INSERT;
> > > +	if (!(txq_flags & ETH_TXQ_FLAGS_NOXSUMSCTP))
> > > +		*offloads |= DEV_TX_OFFLOAD_SCTP_CKSUM;
> > > +	if (!(txq_flags & ETH_TXQ_FLAGS_NOXSUMUDP))
> > > +		*offloads |= DEV_TX_OFFLOAD_UDP_CKSUM;
> > > +	if (!(txq_flags & ETH_TXQ_FLAGS_NOXSUMTCP))
> > > +		*offloads |= DEV_TX_OFFLOAD_TCP_CKSUM; }
> > > +
> > > +/**
> > > + * A copy function between rte_eth_txq_conf offloads API to txq_flags
> > > + * offloads API, to enable application to be agnostic to the PMD
> > > +supported
> > > + * API.
> > > + */
> > > +static void
> > > +rte_eth_copy_txq_offloads(struct rte_eth_txq_conf *txq_conf) {
> > > +	uint32_t *txq_flags = &txq_conf->txq_flags
> > > +	uint64_t offloads = txq_conf->offloads;
> > > +
> > > +	if (!(offloads & DEV_TX_OFFLOAD_MULTI_SEGS))
> > > +		*txq_flags |= ETH_TXQ_FLAGS_NOMULTSEGS;
> > > +	if (!(offloads & DEV_TX_OFFLOAD_VLAN_INSERT))
> > > +		*txq_flags |= ETH_TXQ_FLAGS_NOVLANOFFL;
> > > +	if (!(offloads & DEV_TX_OFFLOAD_SCTP_CKSUM))
> > > +		*txq_flags |= ETH_TXQ_FLAGS_NOXSUMSCTP;
> > > +	if (!(offloads & DEV_TX_OFFLOAD_UDP_CKSUM))
> > > +		*txq_flags |= ETH_TXQ_FLAGS_NOXSUMUDP;
> > > +	if (!(offloads & DEV_TX_OFFLOAD_TCP_CKSUM))
> > > +		*txq_flags |= ETH_TXQ_FLAGS_NOXSUMTCP; }
> > > +
> > >  int
> > >  rte_eth_tx_queue_setup(uint8_t port_id, uint16_t tx_queue_id,
> > >  		       uint16_t nb_tx_desc, unsigned int socket_id, @@ -1145,6
> > > +1278,13 @@ rte_eth_tx_queue_setup(uint8_t port_id, uint16_t
> > tx_queue_id,
> > >  	if (tx_conf == NULL)
> > >  		tx_conf = &dev_info.default_txconf;
> > >
> > > +	if ((dev->data->dev_flags & RTE_ETH_DEV_TXQ_OFFLOAD) &&
> > > +	    (!(tx_conf->txq_flags & ETH_TXQ_FLAGS_IGNORE)))
> > > +		rte_eth_copy_txq_flags(tx_conf);
> > > +	else if (!(dev->data->dev_flags & RTE_ETH_DEV_TXQ_OFFLOAD) &&
> > > +		   (tx_conf->txq_flags & ETH_TXQ_FLAGS_IGNORE))
> > > +		rte_eth_copy_txq_offloads(tx_conf);
> > > +
> >
> > As I said in my previous mail - I think better to always convrert from old
> > txq_flags to new TX offload flags and make each PMD to understand new
> > offload values only.
> > Konstantin
> >
> > >  	return (*dev->dev_ops->tx_queue_setup)(dev, tx_queue_id,
> > nb_tx_desc,
> > >  					       socket_id, tx_conf);
> > >  }
> > > --
> > > 2.12.0



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