Re: [dpdk-dev] [PATCH v7 3/3] net/i40e: enable PCI bus master after reset

["Xing, Beilei" <beilei.xing@intel.com>]

> -----Original Message-----
> From: Wang, Haiyue <haiyue.wang@intel.com>
> Sent: Monday, May 24, 2021 9:24 AM
> To: dev@dpdk.org
> Cc: Zhang, Qi Z <qi.z.zhang@intel.com>; Wang, Liang-min <liang-
> min.wang@intel.com>; david.marchand@redhat.com; Wang, Haiyue
> <haiyue.wang@intel.com>; Xing, Beilei <beilei.xing@intel.com>
> Subject: [PATCH v7 3/3] net/i40e: enable PCI bus master after reset
> 
> The VF reset can be triggered by the PF reset event, then the PCI bus master
> will be cleared, the VF will be not allowed to issue any Memory or I/O
> Requests.
> 
> So after the reset event is detected, always enable the PCI bus master.
> And if failed, the device or system may be in an invalid state, so keep the VF
> reset state to mark it as I/O error.
> 
> Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev_vf.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev_vf.c
> b/drivers/net/i40e/i40e_ethdev_vf.c
> index cb898bdb68..385ebedcd3 100644
> --- a/drivers/net/i40e/i40e_ethdev_vf.c
> +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> @@ -1213,7 +1213,6 @@ i40evf_check_vf_reset_done(struct rte_eth_dev
> *dev)
>  	if (i >= MAX_RESET_WAIT_CNT)
>  		return -1;
> 
> -	vf->vf_reset = false;
>  	vf->pend_msg &= ~PFMSG_RESET_IMPENDING;
> 
>  	return 0;
> @@ -1392,6 +1391,7 @@ i40evf_handle_pf_event(struct rte_eth_dev *dev,
> uint8_t *msg,
>  	switch (pf_msg->event) {
>  	case VIRTCHNL_EVENT_RESET_IMPENDING:
>  		PMD_DRV_LOG(DEBUG,
> "VIRTCHNL_EVENT_RESET_IMPENDING event");
> +		vf->vf_reset = true;
>  		rte_eth_dev_callback_process(dev,
>  				RTE_ETH_EVENT_INTR_RESET, NULL);
>  		break;
> @@ -2468,6 +2468,7 @@ i40evf_dev_close(struct rte_eth_dev *dev)  {
>  	struct i40e_hw *hw = I40E_DEV_PRIVATE_TO_HW(dev->data-
> >dev_private);
>  	struct i40e_vf *vf = I40EVF_DEV_PRIVATE_TO_VF(dev->data-
> >dev_private);
> +	struct rte_pci_device *pci_dev = RTE_ETH_DEV_TO_PCI(dev);
>  	int ret;
> 
>  	if (rte_eal_process_type() != RTE_PROC_PRIMARY) @@ -2490,6
> +2491,16 @@ i40evf_dev_close(struct rte_eth_dev *dev)
>  	i40e_shutdown_adminq(hw);
>  	i40evf_disable_irq0(hw);
> 
> +	/*
> +	 * If the VF is reset via VFLR, the device will be knocked out of bus
> +	 * master mode, and the driver will fail to recover from the reset. Fix
> +	 * this by enabling bus mastering after every reset. In a non-VFLR
> case,
> +	 * the bus master bit will not be disabled, and this call will have no
> +	 * effect.
> +	 */
> +	if (vf->vf_reset && !rte_pci_set_bus_master(pci_dev, true))
> +		vf->vf_reset = false;
> +
>  	rte_free(vf->vf_res);
>  	vf->vf_res = NULL;
>  	rte_free(vf->aq_resp);
> --
> 2.31.1

Acked-by: Beilei Xing <beilei.xing@intel.com>