RE: [PATCH v3] net/iavf: fix iavf query stats in intr thread

["Deng, KaiwenX" <kaiwenx.deng@intel.com>]

> -----Original Message-----
> From: Ferruh Yigit <ferruh.yigit@amd.com>
> Sent: Thursday, March 23, 2023 11:39 PM
> To: Deng, KaiwenX <kaiwenx.deng@intel.com>; dev@dpdk.org
> Cc: stable@dpdk.org; Yang, Qiming <qiming.yang@intel.com>; Zhou, YidingX
> <yidingx.zhou@intel.com>; Chas Williams <chas3@att.com>; Min Hu (Connor)
> <humin29@huawei.com>; Wu, Jingjing <jingjing.wu@intel.com>; Xing, Beilei
> <beilei.xing@intel.com>; Mike Pattrick <mkp@redhat.com>; Zhang, Qi Z
> <qi.z.zhang@intel.com>; Doherty, Declan <declan.doherty@intel.com>;
> Mrzyglod, Daniel T <daniel.t.mrzyglod@intel.com>; Dapeng Yu
> <dapengx.yu@intel.com>
> Subject: Re: [PATCH v3] net/iavf: fix iavf query stats in intr thread
> 
> On 3/22/2023 7:26 AM, Kaiwen Deng wrote:
> > When iavf send query-stats command in eal-intr-thread through virtual
> > channel, there will be no response received from
> > iavf_dev_virtchnl_handler for this command during block and wait.
> > Because iavf_dev_virtchnl_handler is also registered in eal-intr-thread.
> >
> > When vf device is bonded as BONDING_MODE_TLB mode, the slave device
> > update callback will registered in alarm and called by
> > eal-intr-thread, it would also raise the above issue.
> >
> > This commit add to poll the response for VIRTCHNL_OP_GET_STATS when
> it
> > is called by eal-intr-thread to fix this issue.
> >
> > Fixes: 91bf37d250aa ("net/iavf: add lock for VF commands")
> > Fixes: 22b123a36d07 ("net/avf: initialize PMD")
> > Fixes: 7c76a747e68c ("bond: add mode 5")
> > Fixes: 435d523112cc ("net/iavf: fix multi-process shared data")
> > Fixes: cb5c1b91f76f ("net/iavf: add thread for event callbacks")
> 
> 
> Hi Kaiwen,
> 
> Above commit already seems trying to address same issue, it creates "iavf-
> event-thread" control thread to asyncroniously handle the interrupts, in non-
> interrupt context, why it is not working?
> 
> Instead of adding 'rte_thread_is_intr()' checks, can't you make sure all
> interrupts handled in control tread?
> 
> And can you please provide a stack trace in commit log, to describe the issue
> better?
Hi Ferru,
Sorry for my late reply, And thanks for your review.
 
The above commit does not fix this issue when we need to get the returned data.
If we call iavf_query_stats and wait for response statistics in the intr-thread.
iavf_handle_virtchnl_msg is also registered in the intr_thread and will not be 
executed while waiting.

This commit I changed it to polling for replies to commands executed in the interrupt thread.

main thread                                                                                                interrupt thread
     |                                                                                                                               |
     |                                                                                                                               |
iavf_query_stats                                                                                                        |
iavf_execute_vf_cmd                                                                                               |
iavf_aq_send_msg_to_pf  and wait handle complete                                       |
     |                                                                                                                              |
     |-------------------------------------------------------------------------------------------->|
     |                                                                                                                              |
     |                                                                                                       iavf_handle_virtchnl_msg
     |                                                                                                                             |
     |<--------------------------------------------------------------------------------------------|
     |                                                                                                                             |
iavf_execute_vf_cmd get response                                                                      |
     |                                                                                                                             |

The above is the stack trace for the normal execution of iavf_query_stats 
in the main thread.

 interrupt thread
     |
     |
iavf_query_stats
iavf_execute_vf_cmd
iavf_aq_send_msg_to_pf wait handle complete(1 sec)
iavf_execute_vf_cmd timeout
     |
     |
iavf_handle_virtchnl_msg
     |

The above is the stack trace for the abnormal execution of iavf_query_stats 
in the interrupt thread.
> 
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Kaiwen Deng <kaiwenx.deng@intel.com>
> > ---
> > Changes since v2:
> > - Add to poll the response for VIRTCHNL_OP_GET_STATS.
> >
> > Changes since v1:
> > - Add lock to avoid race condition.
> > ---
> > ---
> >  drivers/net/bonding/rte_eth_bond_pmd.c |  7 ++-
> >  drivers/net/iavf/iavf_ethdev.c         |  5 +-
> >  drivers/net/iavf/iavf_vchnl.c          | 71 ++++++++++++++++++--------
> >  3 files changed, 58 insertions(+), 25 deletions(-)
> >
> > diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c
> > b/drivers/net/bonding/rte_eth_bond_pmd.c
> > index f0c4f7d26b..edce621496 100644
> > --- a/drivers/net/bonding/rte_eth_bond_pmd.c
> > +++ b/drivers/net/bonding/rte_eth_bond_pmd.c
> > @@ -894,6 +894,7 @@ bond_ethdev_update_tlb_slave_cb(void *arg)
> >  	uint8_t update_stats = 0;
> >  	uint16_t slave_id;
> >  	uint16_t i;
> > +	int ret;
> >
> >  	internals->slave_update_idx++;
> >
> > @@ -903,7 +904,10 @@ bond_ethdev_update_tlb_slave_cb(void *arg)
> >
> >  	for (i = 0; i < internals->active_slave_count; i++) {
> >  		slave_id = internals->active_slaves[i];
> > -		rte_eth_stats_get(slave_id, &slave_stats);
> > +		ret = rte_eth_stats_get(slave_id, &slave_stats);
> > +		if (ret)
> > +			goto OUT;
> > +
> >  		tx_bytes = slave_stats.obytes - tlb_last_obytets[slave_id];
> >  		bandwidth_left(slave_id, tx_bytes,
> >  				internals->slave_update_idx, &bwg_array[i]);
> @@ -922,6 +926,7 @@
> > bond_ethdev_update_tlb_slave_cb(void *arg)
> >  	for (i = 0; i < slave_count; i++)
> >  		internals->tlb_slaves_order[i] = bwg_array[i].slave;
> >
> > +OUT:
> >  	rte_eal_alarm_set(REORDER_PERIOD_MS * 1000,
> bond_ethdev_update_tlb_slave_cb,
> >  			(struct bond_dev_private *)internals);  } diff --git
> > a/drivers/net/iavf/iavf_ethdev.c b/drivers/net/iavf/iavf_ethdev.c
> > index 3196210f2c..d6e1f1a7f4 100644
> > --- a/drivers/net/iavf/iavf_ethdev.c
> > +++ b/drivers/net/iavf/iavf_ethdev.c
> > @@ -2607,6 +2607,9 @@ iavf_dev_init(struct rte_eth_dev *eth_dev)
> >  	adapter->dev_data = eth_dev->data;
> >  	adapter->stopped = 1;
> >
> > +	if (iavf_dev_event_handler_init())
> > +		goto init_vf_err;
> > +
> >  	if (iavf_init_vf(eth_dev) != 0) {
> >  		PMD_INIT_LOG(ERR, "Init vf failed");
> >  		return -1;
> > @@ -2634,8 +2637,6 @@ iavf_dev_init(struct rte_eth_dev *eth_dev)
> >  	rte_ether_addr_copy((struct rte_ether_addr *)hw->mac.addr,
> >  			&eth_dev->data->mac_addrs[0]);
> >
> > -	if (iavf_dev_event_handler_init())
> > -		goto init_vf_err;
> >
> >  	if (vf->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_WB_ON_ITR)
> {
> >  		/* register callback func to eal lib */ diff --git
> > a/drivers/net/iavf/iavf_vchnl.c b/drivers/net/iavf/iavf_vchnl.c index
> > 9adaadb173..aeffb07cca 100644
> > --- a/drivers/net/iavf/iavf_vchnl.c
> > +++ b/drivers/net/iavf/iavf_vchnl.c
> > @@ -256,6 +256,7 @@ iavf_read_msg_from_pf(struct iavf_adapter
> *adapter, uint16_t buf_len,
> >  				vf->link_speed =
> iavf_convert_link_speed(speed);
> >  			}
> >  			iavf_dev_link_update(vf->eth_dev, 0);
> > +			iavf_dev_event_post(vf->eth_dev,
> RTE_ETH_EVENT_INTR_LSC, NULL, 0);
> >  			PMD_DRV_LOG(INFO, "Link status update:%s",
> >  					vf->link_up ? "up" : "down");
> >  			break;
> > @@ -368,28 +369,48 @@ iavf_execute_vf_cmd(struct iavf_adapter
> *adapter, struct iavf_cmd_info *args,
> >  		_clear_cmd(vf);
> >  		break;
> >  	default:
> > -		/* For other virtchnl ops in running time,
> > -		 * wait for the cmd done flag.
> > -		 */
> > -		do {
> > -			if (vf->pend_cmd == VIRTCHNL_OP_UNKNOWN)
> > -				break;
> > -			iavf_msec_delay(ASQ_DELAY_MS);
> > -			/* If don't read msg or read sys event, continue */
> > -		} while (i++ < MAX_TRY_TIMES);
> > -
> > -		if (i >= MAX_TRY_TIMES) {
> > -			PMD_DRV_LOG(ERR, "No response for cmd %d",
> args->ops);
> > +		if (rte_thread_is_intr()) {
> > +			/* For virtchnl ops were executed in eal_intr_thread,
> > +			 * need to poll the response.
> > +			 */
> > +			do {
> > +				result = iavf_read_msg_from_pf(adapter,
> args->out_size,
> > +							args->out_buffer);
> > +				if (result == IAVF_MSG_CMD)
> > +					break;
> > +				iavf_msec_delay(ASQ_DELAY_MS);
> > +			} while (i++ < MAX_TRY_TIMES);
> > +			if (i >= MAX_TRY_TIMES ||
> > +				vf->cmd_retval !=
> VIRTCHNL_STATUS_SUCCESS) {
> > +				err = -1;
> > +				PMD_DRV_LOG(ERR, "No response or return
> failure (%d)"
> > +						" for cmd %d", vf-
> >cmd_retval, args->ops);
> > +			}
> >  			_clear_cmd(vf);
> > -			err = -EIO;
> > -		} else if (vf->cmd_retval ==
> > -			   VIRTCHNL_STATUS_ERR_NOT_SUPPORTED) {
> > -			PMD_DRV_LOG(ERR, "Cmd %d not supported", args-
> >ops);
> > -			err = -ENOTSUP;
> > -		} else if (vf->cmd_retval != VIRTCHNL_STATUS_SUCCESS) {
> > -			PMD_DRV_LOG(ERR, "Return failure %d for cmd %d",
> > -				    vf->cmd_retval, args->ops);
> > -			err = -EINVAL;
> > +		} else {
> > +			/* For other virtchnl ops in running time,
> > +			 * wait for the cmd done flag.
> > +			 */
> > +			do {
> > +				if (vf->pend_cmd ==
> VIRTCHNL_OP_UNKNOWN)
> > +					break;
> > +				iavf_msec_delay(ASQ_DELAY_MS);
> > +				/* If don't read msg or read sys event,
> continue */
> > +			} while (i++ < MAX_TRY_TIMES);
> > +
> > +			if (i >= MAX_TRY_TIMES) {
> > +				PMD_DRV_LOG(ERR, "No response for
> cmd %d", args->ops);
> > +				_clear_cmd(vf);
> > +				err = -EIO;
> > +			} else if (vf->cmd_retval ==
> > +				VIRTCHNL_STATUS_ERR_NOT_SUPPORTED) {
> > +				PMD_DRV_LOG(ERR, "Cmd %d not
> supported", args->ops);
> > +				err = -ENOTSUP;
> > +			} else if (vf->cmd_retval !=
> VIRTCHNL_STATUS_SUCCESS) {
> > +				PMD_DRV_LOG(ERR, "Return failure %d for
> cmd %d",
> > +						vf->cmd_retval, args->ops);
> > +				err = -EINVAL;
> > +			}
> >  		}
> >  		break;
> >  	}
> > @@ -403,8 +424,14 @@ iavf_execute_vf_cmd_safe(struct iavf_adapter
> > *adapter,  {
> >  	struct iavf_info *vf = IAVF_DEV_PRIVATE_TO_VF(adapter);
> >  	int ret;
> > +	int is_intr_thread = rte_thread_is_intr();
> >
> > -	rte_spinlock_lock(&vf->aq_lock);
> > +	if (is_intr_thread) {
> > +		if (!rte_spinlock_trylock(&vf->aq_lock))
> > +			return -EIO;
> > +	} else {
> > +		rte_spinlock_lock(&vf->aq_lock);
> > +	}
> >  	ret = iavf_execute_vf_cmd(adapter, args, async);
> >  	rte_spinlock_unlock(&vf->aq_lock);
> >