Re: [dpdk-stable] [PATCH v2] net/i40e: fix request queue fail in VF

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: Zhu, TaoX
> Sent: Friday, July 19, 2019 11:18 AM
> To: Xing, Beilei <beilei.xing@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
> Cc: dev@dpdk.org; Zhu, TaoX <taox.zhu@intel.com>; stable@dpdk.org
> Subject: [PATCH v2] net/i40e: fix request queue fail in VF
> 
> From: Zhu Tao <taox.zhu@intel.com>
> 
> When the VF configuration is larger than the number of queues reserved by PF,
> VF sends the request queue command through admin queue. When PF
> received this command, it may reset the VF and send a notification before
> resetting. If this notification is read by the timed task alarm, Task request
> queue will lost notification. This patch Mark vf_reset, pend_msg flag just as
> task request queue has received notification in task alarm.
> 
> Fixes: 864a800d70 ("net/i40e: remove VF interrupt handler")
> Fixes: ee653bd800 ("net/i40e: determine number of queues per VF at run
> time")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Zhu Tao <taox.zhu@intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev_vf.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev_vf.c
> b/drivers/net/i40e/i40e_ethdev_vf.c
> index 5be32b069..3b9740c08 100644
> --- a/drivers/net/i40e/i40e_ethdev_vf.c
> +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> @@ -1332,6 +1332,10 @@ i40evf_handle_pf_event(struct rte_eth_dev *dev,
> uint8_t *msg,
>  		PMD_DRV_LOG(DEBUG, "VIRTCHNL_EVENT_RESET_IMPENDING
> event");
>  		_rte_eth_dev_callback_process(dev, RTE_ETH_EVENT_INTR_RESET,
>  					      NULL);
> +		if (!vf->vf_reset) {
> +			vf->vf_reset = true;
> +			vf->pend_msg|= PFMSG_RESET_IMPENDING;

You current solution rely on we can always can get a dummy event after the VIRTCHNL_EVENT_RESET_IMPENDING event we needed, but I'm not sure if it is guaranteed

If the issue is due to the race condition between i40evf_execute_vf_cmd and i40evf_dev_alarm_handler
Why not just disable the adminq interrupt before i40evf_request_queues and enable it back after it?

> +		}
>  		break;
>  	case VIRTCHNL_EVENT_LINK_CHANGE:
>  		PMD_DRV_LOG(DEBUG, "VIRTCHNL_EVENT_LINK_CHANGE event");
> --
> 2.17.1