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

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

> -----Original Message-----
> From: Dai, Wei
> Sent: Thursday, December 28, 2017 12:39 PM
> To: Zhang, Qi Z <qi.z.zhang@intel.com>; Lu, Wenzhuo
> <wenzhuo.lu@intel.com>
> Cc: dev@dpdk.org; Wang, Liang-min <liang-min.wang@intel.com>;
> stable@dpdk.org
> Subject: RE: [PATCH 1/2] net/ixgbe: fix mailbox interrupt handler
> 
> 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);

Thanks for the suggestion.

I think the patch try to keep things unchanged when a PF reset happen, but it is not going to cover the case that PF reset interrupt and a foreground VF to PF request happen simultaneously which is an knowing issue
Your suggestion may help on that, but it is not a complete fix. I think it will be better to have a separate patch that focus on it.

Regards
Qi
> 
> > -----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