Re: [PATCH v5] net/bonding: call Tx prepare before Tx burst

[fengchengwen <fengchengwen@huawei.com>]

Hi Thomas, Ferruh and Andrew

   This patch already reviewed by Humin and Chas, Could it accepted in 
22.11 ?

Thanks

On 2022/10/15 23:26, Chas Williams wrote:
> This looks fine. Thanks for making the changes!
>
> Signed-off-by: Chas Williams <3chas3@gmail.com>
>
> On 10/11/22 09:20, Chengwen Feng wrote:
>> Normally, to use the HW offloads capability (e.g. checksum and TSO) in
>> the Tx direction, the application needs to call rte_eth_tx_prepare() to
>> do some adjustment with the packets before sending them. But the
>> tx_prepare callback of the bonding driver is not implemented. Therefore,
>> the sent packets may have errors (e.g. checksum errors).
>>
>> However, it is difficult to design the tx_prepare callback for bonding
>> driver. Because when a bonded device sends packets, the bonded device
>> allocates the packets to different slave devices based on the real-time
>> link status and bonding mode. That is, it is very difficult for the
>> bonded device to determine which slave device's prepare function should
>> be invoked.
>>
>> So in this patch, the tx_prepare callback of bonding driver is not
>> implemented. Instead, the rte_eth_tx_prepare() will be called before
>> rte_eth_tx_burst(). In this way, all tx_offloads can be processed
>> correctly for all NIC devices.
>>
>> Note: because it is rara that bond different PMDs together, so just
>> call tx-prepare once in broadcast bonding mode.
>>
>> Also the following description was added to the rte_eth_tx_burst()
>> function:
>> "@note This function must not modify mbufs (including packets data)
>> unless the refcnt is 1. The exception is the bonding PMD, which does not
>> have tx-prepare function, in this case, mbufs maybe modified."
>>
>> Signed-off-by: Chengchang Tang <tangchengchang@huawei.com>
>> Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
>> Reviewed-by: Min Hu (Connor) <humin29@huawei.com>
>>
>> ---
>> v5: address Chas's comments.
>> v4: address Chas and Konstantin's comments.
>> v3: support tx-prepare when Tx internal generate mbufs.
>> v2: support tx-prepare enable flag and fail stats.
>>
>> ---
>>   drivers/net/bonding/rte_eth_bond_8023ad.c | 10 ++++--
>>   drivers/net/bonding/rte_eth_bond_pmd.c    | 37 ++++++++++++++++++-----
>>   lib/ethdev/rte_ethdev.h                   |  4 +++
>>   3 files changed, 41 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/net/bonding/rte_eth_bond_8023ad.c 
>> b/drivers/net/bonding/rte_eth_bond_8023ad.c
>> index b3cddd8a20..29a71ae0bf 100644
>> --- a/drivers/net/bonding/rte_eth_bond_8023ad.c
>> +++ b/drivers/net/bonding/rte_eth_bond_8023ad.c
>> @@ -636,9 +636,12 @@ tx_machine(struct bond_dev_private *internals, 
>> uint16_t slave_id)
>>               return;
>>           }
>>       } else {
>> -        uint16_t pkts_sent = rte_eth_tx_burst(slave_id,
>> +        uint16_t pkts_sent = rte_eth_tx_prepare(slave_id,
>>                   internals->mode4.dedicated_queues.tx_qid,
>>                   &lacp_pkt, 1);
>> +        pkts_sent = rte_eth_tx_burst(slave_id,
>> +                internals->mode4.dedicated_queues.tx_qid,
>> +                &lacp_pkt, pkts_sent);
>>           if (pkts_sent != 1) {
>>               rte_pktmbuf_free(lacp_pkt);
>>               set_warning_flags(port, WRN_TX_QUEUE_FULL);
>> @@ -1371,9 +1374,12 @@ bond_mode_8023ad_handle_slow_pkt(struct 
>> bond_dev_private *internals,
>>               }
>>           } else {
>>               /* Send packet directly to the slow queue */
>> -            uint16_t tx_count = rte_eth_tx_burst(slave_id,
>> +            uint16_t tx_count = rte_eth_tx_prepare(slave_id,
>> internals->mode4.dedicated_queues.tx_qid,
>>                       &pkt, 1);
>> +            tx_count = rte_eth_tx_burst(slave_id,
>> + internals->mode4.dedicated_queues.tx_qid,
>> +                    &pkt, tx_count);
>>               if (tx_count != 1) {
>>                   /* reset timer */
>>                   port->rx_marker_timer = 0;
>> diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c 
>> b/drivers/net/bonding/rte_eth_bond_pmd.c
>> index 4081b21338..a2c68ec9bc 100644
>> --- a/drivers/net/bonding/rte_eth_bond_pmd.c
>> +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
>> @@ -602,8 +602,11 @@ bond_ethdev_tx_burst_round_robin(void *queue, 
>> struct rte_mbuf **bufs,
>>       /* Send packet burst on each slave device */
>>       for (i = 0; i < num_of_slaves; i++) {
>>           if (slave_nb_pkts[i] > 0) {
>> +            num_tx_slave = rte_eth_tx_prepare(slaves[i],
>> +                    bd_tx_q->queue_id, slave_bufs[i],
>> +                    slave_nb_pkts[i]);
>>               num_tx_slave = rte_eth_tx_burst(slaves[i], 
>> bd_tx_q->queue_id,
>> -                    slave_bufs[i], slave_nb_pkts[i]);
>> +                    slave_bufs[i], num_tx_slave);
>>                 /* if tx burst fails move packets to end of bufs */
>>               if (unlikely(num_tx_slave < slave_nb_pkts[i])) {
>> @@ -628,6 +631,7 @@ bond_ethdev_tx_burst_active_backup(void *queue,
>>   {
>>       struct bond_dev_private *internals;
>>       struct bond_tx_queue *bd_tx_q;
>> +    uint16_t nb_prep_pkts;
>>         bd_tx_q = (struct bond_tx_queue *)queue;
>>       internals = bd_tx_q->dev_private;
>> @@ -635,8 +639,11 @@ bond_ethdev_tx_burst_active_backup(void *queue,
>>       if (internals->active_slave_count < 1)
>>           return 0;
>>   +    nb_prep_pkts = 
>> rte_eth_tx_prepare(internals->current_primary_port,
>> +                bd_tx_q->queue_id, bufs, nb_pkts);
>> +
>>       return rte_eth_tx_burst(internals->current_primary_port, 
>> bd_tx_q->queue_id,
>> -            bufs, nb_pkts);
>> +            bufs, nb_prep_pkts);
>>   }
>>     static inline uint16_t
>> @@ -910,7 +917,7 @@ bond_ethdev_tx_burst_tlb(void *queue, struct 
>> rte_mbuf **bufs, uint16_t nb_pkts)
>>         struct rte_eth_dev *primary_port =
>>               &rte_eth_devices[internals->primary_port];
>> -    uint16_t num_tx_total = 0;
>> +    uint16_t num_tx_total = 0, num_tx_prep;
>>       uint16_t i, j;
>>         uint16_t num_of_slaves = internals->active_slave_count;
>> @@ -951,8 +958,10 @@ bond_ethdev_tx_burst_tlb(void *queue, struct 
>> rte_mbuf **bufs, uint16_t nb_pkts)
>>   #endif
>>           }
>>   -        num_tx_total += rte_eth_tx_burst(slaves[i], 
>> bd_tx_q->queue_id,
>> +        num_tx_prep = rte_eth_tx_prepare(slaves[i], bd_tx_q->queue_id,
>>                   bufs + num_tx_total, nb_pkts - num_tx_total);
>> +        num_tx_total += rte_eth_tx_burst(slaves[i], bd_tx_q->queue_id,
>> +                bufs + num_tx_total, num_tx_prep);
>>             if (num_tx_total == nb_pkts)
>>               break;
>> @@ -1064,8 +1073,10 @@ bond_ethdev_tx_burst_alb(void *queue, struct 
>> rte_mbuf **bufs, uint16_t nb_pkts)
>>       /* Send ARP packets on proper slaves */
>>       for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
>>           if (slave_bufs_pkts[i] > 0) {
>> -            num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id,
>> +            num_send = rte_eth_tx_prepare(i, bd_tx_q->queue_id,
>>                       slave_bufs[i], slave_bufs_pkts[i]);
>> +            num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id,
>> +                    slave_bufs[i], num_send);
>>               for (j = 0; j < slave_bufs_pkts[i] - num_send; j++) {
>>                   bufs[nb_pkts - 1 - num_not_send - j] =
>>                           slave_bufs[i][nb_pkts - 1 - j];
>> @@ -1088,8 +1099,10 @@ bond_ethdev_tx_burst_alb(void *queue, struct 
>> rte_mbuf **bufs, uint16_t nb_pkts)
>>       /* Send update packets on proper slaves */
>>       for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
>>           if (update_bufs_pkts[i] > 0) {
>> +            num_send = rte_eth_tx_prepare(i, bd_tx_q->queue_id,
>> +                    update_bufs[i], update_bufs_pkts[i]);
>>               num_send = rte_eth_tx_burst(i, bd_tx_q->queue_id, 
>> update_bufs[i],
>> -                    update_bufs_pkts[i]);
>> +                    num_send);
>>               for (j = num_send; j < update_bufs_pkts[i]; j++) {
>>                   rte_pktmbuf_free(update_bufs[i][j]);
>>               }
>> @@ -1158,9 +1171,12 @@ tx_burst_balance(void *queue, struct rte_mbuf 
>> **bufs, uint16_t nb_bufs,
>>           if (slave_nb_bufs[i] == 0)
>>               continue;
>>   -        slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
>> +        slave_tx_count = rte_eth_tx_prepare(slave_port_ids[i],
>>                   bd_tx_q->queue_id, slave_bufs[i],
>>                   slave_nb_bufs[i]);
>> +        slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
>> +                bd_tx_q->queue_id, slave_bufs[i],
>> +                slave_tx_count);
>>             total_tx_count += slave_tx_count;
>>   @@ -1243,8 +1259,10 @@ tx_burst_8023ad(void *queue, struct rte_mbuf 
>> **bufs, uint16_t nb_bufs,
>>             if (rte_ring_dequeue(port->tx_ring,
>>                        (void **)&ctrl_pkt) != -ENOENT) {
>> -            slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
>> +            slave_tx_count = rte_eth_tx_prepare(slave_port_ids[i],
>>                       bd_tx_q->queue_id, &ctrl_pkt, 1);
>> +            slave_tx_count = rte_eth_tx_burst(slave_port_ids[i],
>> +                    bd_tx_q->queue_id, &ctrl_pkt, slave_tx_count);
>>               /*
>>                * re-enqueue LAG control plane packets to buffering
>>                * ring if transmission fails so the packet isn't lost.
>> @@ -1316,6 +1334,9 @@ bond_ethdev_tx_burst_broadcast(void *queue, 
>> struct rte_mbuf **bufs,
>>       if (num_of_slaves < 1)
>>           return 0;
>>   +    /* It is rare that bond different PMDs together, so just call 
>> tx-prepare once */
>> +    nb_pkts = rte_eth_tx_prepare(slaves[0], bd_tx_q->queue_id, bufs, 
>> nb_pkts);
>> +
>>       /* Increment reference count on mbufs */
>>       for (i = 0; i < nb_pkts; i++)
>>           rte_pktmbuf_refcnt_update(bufs[i], num_of_slaves - 1);
>> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
>> index d43a638aff..e92139f105 100644
>> --- a/lib/ethdev/rte_ethdev.h
>> +++ b/lib/ethdev/rte_ethdev.h
>> @@ -6095,6 +6095,10 @@ uint16_t rte_eth_call_tx_callbacks(uint16_t 
>> port_id, uint16_t queue_id,
>>    * @see rte_eth_tx_prepare to perform some prior checks or adjustments
>>    * for offloads.
>>    *
>> + * @note This function must not modify mbufs (including packets 
>> data) unless
>> + * the refcnt is 1. The exception is the bonding PMD, which does not 
>> have
>> + * tx-prepare function, in this case, mbufs maybe modified.
>> + *
>>    * @param port_id
>>    *   The port identifier of the Ethernet device.
>>    * @param queue_id