Re: [dpdk-dev] [PATCH 1/2] net/ixgbe: fix mailbox interrupt handler

["Dai, Wei" <wei.dai@intel.com>]

According to step 7 & 8 in Table 7-74 PF-to-VF Messaging Flow in 82599 datasheet,
The calling of ixgbe_read_mbx( ) can be replaced by following lines to avoid touching ->mbx.v2p_mailbox,
IXGBE_WRITE_REG(hw, IXGBE_VFMAILBOX, IXGBE_VFMAILBOX_ACK);

> -----Original Message-----
> From: Zhang, Qi Z
> Sent: Thursday, December 28, 2017 4:22 AM
> To: Lu, Wenzhuo <wenzhuo.lu@intel.com>
> Cc: dev@dpdk.org; Dai, Wei <wei.dai@intel.com>; Wang, Liang-min
> <liang-min.wang@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>;
> stable@dpdk.org
> Subject: [PATCH 1/2] net/ixgbe: fix mailbox interrupt handler
> 
> Mailbox interrupt handler only take care of PF reset notification, for other
> message ixgbe_read_mbx should not be called since it get chance to break
> the foreground VF to PF communication.
> This can be simply repeated by
> testpmd>rx_vlan rm all 0
> 
> Fixes: 77234603fba0 ("net/ixgbe: support VF mailbox interrupt for link
> up/down")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
> ---
>  drivers/net/ixgbe/ixgbe_ethdev.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> b/drivers/net/ixgbe/ixgbe_ethdev.c
> index ff19a56..02121f4 100644
> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> @@ -8165,13 +8165,17 @@ static void ixgbevf_mbx_process(struct
> rte_eth_dev *dev)
>  	struct ixgbe_hw *hw =
> IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
>  	u32 in_msg = 0;
> 
> -	if (ixgbe_read_mbx(hw, &in_msg, 1, 0))
> -		return;
> +	/* peek the message first */
> +	in_msg = IXGBE_READ_REG(hw, IXGBE_VFMBMEM);
> 
>  	/* PF reset VF event */
> -	if (in_msg == IXGBE_PF_CONTROL_MSG)
> +	if (in_msg == IXGBE_PF_CONTROL_MSG) {
> +		/* dummy mbx read to ack pf */
> +		if (ixgbe_read_mbx(hw, &in_msg, 1, 0))
> +			return;
>  		_rte_eth_dev_callback_process(dev,
> RTE_ETH_EVENT_INTR_RESET,
>  					      NULL, NULL);
> +	}
>  }
> 
>  static int
> --
> 2.7.4