[dpdk-dev] [PATCH] net/i40e: force promiscuous state after VF reset

[Zhang, Xiao]

Hi Eelco,

Seems you missed this mail.

Thanks,
Xiao

> -----Original Message-----
> From: Zhang, Xiao
> Sent: Wednesday, November 6, 2019 12:58 PM
> To: Eelco Chaudron <echaudro at redhat.com>; Xing, Beilei
> <beilei.xing at intel.com>
> Cc: Zhang, Qi Z <qi.z.zhang at intel.com>; dev at dpdk.org
> Subject: RE: [dpdk-dev] [PATCH] net/i40e: force promiscuous state after VF
> reset
> 
> Hi Eelco
> 
> > -----Original Message-----
> > From: Eelco Chaudron [mailto:echaudro at redhat.com]
> > Sent: Friday, November 1, 2019 4:13 PM
> > To: Xing, Beilei <beilei.xing at intel.com>; Zhang, Xiao
> > <xiao.zhang at intel.com>
> > Cc: Zhang, Qi Z <qi.z.zhang at intel.com>; dev at dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH] net/i40e: force promiscuous state
> > after VF reset
> >
> >
> >
> > On 1 Nov 2019, at 3:38, Xing, Beilei wrote:
> >
> > >> -----Original Message-----
> > >> From: Eelco Chaudron [mailto:echaudro at redhat.com]
> > >> Sent: Tuesday, October 29, 2019 3:47 PM
> > >> To: Zhang, Xiao <xiao.zhang at intel.com>; Xing, Beilei
> > >> <beilei.xing at intel.com>
> > >> Cc: Zhang, Qi Z <qi.z.zhang at intel.com>; dev at dpdk.org
> > >> Subject: Re: [dpdk-dev] [PATCH] net/i40e: force promiscuous state
> > >> after VF reset
> > >>
> > >>
> > >>
> > >> On 29 Oct 2019, at 8:39, Zhang, Xiao wrote:
> > >>
> > >>>> -----Original Message-----
> > >>>> From: Eelco Chaudron <echaudro at redhat.com>
> > >>>> Sent: Friday, October 25, 2019 5:24 PM
> > >>>> To: Xing, Beilei <beilei.xing at intel.com>; Zhang, Xiao
> > >>>> <xiao.zhang at intel.com>
> > >>>> Cc: Zhang, Qi Z <qi.z.zhang at intel.com>; dev at dpdk.org
> > >>>> Subject: Re: [dpdk-dev] [PATCH] net/i40e: force promiscuous state
> > >>>> after VF reset
> > >>>>
> > >>>>
> > >>>>
> > >>>> On 17 Oct 2019, at 8:34, Xing, Beilei wrote:
> > >>>>
> > >>>>>> On 17 Sep 2019, at 9:40, Eelco Chaudron wrote:
> > >>>>>>
> > >>>>>>> Even though the device reset is successful, disabling
> > >>>>>>> promiscuous mode might not always succeed, causing enabling it
> > >>>>>>> after reset to fail.
> > >>>>>>> This would happen when the kernel driver requires a reset of
> > >>>>>>> the VF.
> > >>>>>>>
> > >>>>>>> This patch resets the internal state, so next time promiscuous
> > >>>>>>> mode is configured it will be enabled.
> > >>>>>>>
> > >>>>>>> Signed-off-by: Eelco Chaudron <echaudro at redhat.com>
> > >>>>>>> ---
> > >>>>>>>  drivers/net/i40e/i40e_ethdev_vf.c | 10 ++++++++++
> > >>>>>>>  1 file changed, 10 insertions(+)
> > >>>>>>>
> > >>>>>>> diff --git a/drivers/net/i40e/i40e_ethdev_vf.c
> > >>>>>>> b/drivers/net/i40e/i40e_ethdev_vf.c
> > >>>>>>> index 551f6fa..e0f99a4 100644
> > >>>>>>> --- a/drivers/net/i40e/i40e_ethdev_vf.c
> > >>>>>>> +++ b/drivers/net/i40e/i40e_ethdev_vf.c
> > >>>>>>> @@ -2276,11 +2276,21 @@ static int
> > >>>>>>> eth_i40evf_pci_remove(struct rte_pci_device *pci_dev)
> > >>>>>>> i40evf_dev_reset(struct rte_eth_dev
> > >>>>>>> *dev)
> > >>>>>>> {
> > >>>>>>>  	int ret;
> > >>>>>>> +	struct i40e_vf *vf =
> > >>>>>>> I40EVF_DEV_PRIVATE_TO_VF(dev->data->dev_private);
> > >>>>>>>
> > >>>>>>>  	ret = i40evf_dev_uninit(dev);
> > >>>>>>>  	if (ret)
> > >>>>>>>  		return ret;
> > >>>>>>>
> > >>>>>>> +	/*
> > >>>>>>> +	 * Even though the device reset is successful disabling
> > >>>>>>> promiscuous
> > >>>>>>> +	 * mode might not always succeed, causing enabling it after
> > >>>>>>> reset
> > >>>>>>> to
> > >>>>>
> > >>>>> I think we need to root cause why fail to disable promiscuous
> > >>>>> mode and try to fix it first.
> > >>>>
> > >>>> I’ve copied in Xiao who helped me identify the issue in your
> > >>>> driver.
> > >>>>
> > >>>> The issue is because the change from kernel pf was not synced to
> > >>>> DPDK vf during the closing period of reset, so we get this
> > >>>> failure. Xiao can you add more details?
> > >>>>
> > >>>
> > >>> The root cause is when kernel pf generate DPDK vf reset event, the
> > >>> flag
> > >>> vf->promisc_unicast_enabled will not be cleared but promiscuous
> > >>> vf->mode
> > >>> is
> > >>> disabled. When trying to enable promiscuous mode next time by
> > >>> calling i40evf_dev_promiscuous_enable won't work because it will
> > >>> check the
> > >>> vf->promisc_unicast_enabled flag first.
> > >>>
> > >>> static int
> > >>> i40evf_dev_promiscuous_enable(struct rte_eth_dev *dev) { ...
> > >>>     /* If enabled, just return */
> > >>>     if (vf->promisc_unicast_enabled)
> > >>>         return 0;
> > >>> ...
> > >>> }
> > >>>
> > >>> Hi Eelco,
> > >>>
> > >>> I think you may need add more detailed message in the commit log
> > >>> or comments.
> > >>
> > >> My interpretation of the request was that Beilei wanted to know why
> > >> disabling promiscuous mode in HW was failing. Beilei can you
> > >> comment, is the additional description from Xiao enough?
> > >
> > > Yes, promisc_unicast_enabled flag is not cleared during vf reset
> > > because fail to disable promiscuous mode, So I think we need to root
> > > cause why fail to  disable promiscuous mode first.
> > > This patch looks like a workaround but not a fix.
> > >
> >
> > This was debugged together with Xiao and from what I understand is
> > that DPDK fails to reset promiscuous mode in hardware as PF and VF
> > operations are not synced between kernel and DPDK.
> >
> > Xiao told me this could not be fixed in another way, Xiao can you
> > comment?
> >
> 
> Checked again, the root cause is not synced issue between kernel and DPDK
> during reset.
> Suggest to remove the checking and setting of promisc_unicast_enabled flag,
> since this flag is only used when enable/disable promiscuous mode.
> Considering the un-synced issue, it will be more clean if remove the flag.
> Also same with flag promisc_multicast_enabled.
> 
> > >>
> > >>>>
> > >>>>>>> +	 * fail. This would happen when the kernel driver requires a
> > >>>>>>> reset
> > >>>>>>> +	 * of the VF.
> > >>>>>>> +	 */
> > >>>>>>> +	if (rte_eal_process_type() == RTE_PROC_PRIMARY)
> > >>>>>>> +		vf->promisc_unicast_enabled = FALSE;
> > >>>>>>> +
> > >>>>>>>  	ret = i40evf_dev_init(dev);
> > >>>>>>>
> > >>>>>>>  	return ret;
> > >>>>>>> --
> > >>>>>>> 1.8.3.1