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: Monday, March 27, 2023 8:38 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>; Zhang, Helin <helin.zhang@intel.com>;
> Mcnamara, John <john.mcnamara@intel.com>; Thomas Monjalon
> <thomas@monjalon.net>
> Subject: Re: [PATCH v3] net/iavf: fix iavf query stats in intr thread
> 
> On 3/27/2023 1:31 PM, Ferruh Yigit wrote:
> > On 3/27/2023 6:31 AM, Deng, KaiwenX wrote:
> >>
> >>
> >>> -----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.
> >>
> >
> > Got it, since return value is required, API can't be called asyncroniously.
> >
> >
> >
> > I think 'rte_thread_is_intr()' checks may cause more trouble for you
> > in long term,
> >
> > - why 'iavf_query_stats()' is called in the iterrupt thread, can it be
> > prevented?
> >
> > - does it make sense to allways poll messages from PF (for simplification)?
> >
> >
> > If answer to both are 'No', I am OK to continue with current proposal
> > if you are happy with it.
> >
> 
> 
> btw, how critical is this issue?
> 
> If it is critical, I am OK to get it as it is for this release and investigate it further
> for next release, since only a few days left for this release.
> 
This is not a very crtical issue, we can wait for a more appropriate solution.

Thanks.
> 
> >
> >> 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);
> >>>>
> >>
> >