Hi Luca,

> -----Original Message-----
> From: Luca Boccassi [mailto:lboccass@Brocade.com]
> Sent: Tuesday, July 5, 2016 5:53 PM
> To: Lu, Wenzhuo
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v6 0/4] support reset of VF link
> 
> On Tue, 2016-07-05 at 00:52 +0000, Lu, Wenzhuo wrote:
> > Hi Luca,
> >
> >
> > > -----Original Message-----
> > > From: Luca Boccassi [mailto:lboccass@Brocade.com]
> > > Sent: Monday, July 4, 2016 11:48 PM
> > > To: Lu, Wenzhuo
> > > Cc: dev@dpdk.org
> > > Subject: Re: [dpdk-dev] [PATCH v6 0/4] support reset of VF link
> > >
> > > On Mon, 2016-06-20 at 14:24 +0800, Wenzhuo Lu wrote:
> > > > If the PF link is down and up, VF link will not work accordingly.
> > > > This patch set addes the support of VF link reset. So, when VF
> > > > receices the messges of physical link down/up. APP can reset the
> > > > VF link and let it recover.
> > > >
> > > > PS: This patch set is splitted from a previous patch set,
> > > > *automatic link recovery on ixgbe/igb VF*, and it's base on the
> > > > patch set *support mailbox interruption on ixgbe/igb VF*.
> > > >
> > > > Wenzhuo Lu (3):
> > > >   lib/librte_ether: support device reset
> > > >   ixgbe: implement device reset on VF
> > > >   igb: implement device reset on VF
> > > >
> > > > Zhe Tao (1):
> > > >   i40e: implement device reset on VF
> > > >
> > > > v1:
> > > > - Added the implementation for the VF reset functionality.
> > > > v2:
> > > > - Changed the i40e related operations during VF reset.
> > > > v3:
> > > > - Resent the patches because of the mail sent issue.
> > > > v4:
> > > > - Removed some VF reset emulation code.
> > > > v5:
> > > > - Removed all the code related with lock.
> > > > v6:
> > > > - Updated the NIC feature overview matrix.
> > > > - Added more explanation in the doxygen comment of reset API.
> > > >
> > > >  doc/guides/nics/overview.rst           |  1 +
> > > >  doc/guides/rel_notes/release_16_07.rst | 13 ++++++
> > > >  drivers/net/e1000/igb_ethdev.c         | 59 ++++++++++++++++++++++++
> > > >  drivers/net/i40e/i40e_ethdev.h         |  4 ++
> > > >  drivers/net/i40e/i40e_ethdev_vf.c      | 83
> > > ++++++++++++++++++++++++++++++++++
> > > >  drivers/net/i40e/i40e_rxtx.c           | 10 ++++
> > > >  drivers/net/i40e/i40e_rxtx.h           |  4 ++
> > > >  drivers/net/ixgbe/ixgbe_ethdev.c       | 64 +++++++++++++++++++++++++-
> > > >  drivers/net/ixgbe/ixgbe_ethdev.h       |  2 +-
> > > >  drivers/net/ixgbe/ixgbe_rxtx.c         | 12 +++--
> > > >  lib/librte_ether/rte_ethdev.c          | 17 +++++++
> > > >  lib/librte_ether/rte_ethdev.h          | 24 ++++++++++
> > > >  lib/librte_ether/rte_ether_version.map |  7 +++
> > > >  13 files changed, 295 insertions(+), 5 deletions(-)
> > >
> > > Hello Wenzhuo,
> > >
> > > I'm testing this patchset, but I am sporadically running into an
> > > issue where the VFs reset fails after the PF flaps.
> > >
> > > I have a VM running on a KVM box with a X540-AT2, passing 2 VFs in.
> > >
> > > I am using calling rte_eth_dev_reset in response to a
> > > RTE_ETH_EVENT_INTR_RESET callback, and the following errors appear
> > > in the
> > > log:
> > >
> > > PMD: ixgbevf_dev_reset(): Ixgbe VF reset: Failed to update link.
> > > PMD: ixgbe_alloc_rx_queue_mbufs(): RX mbuf alloc failed queue_id=0
> > > PMD: ixgbevf_dev_start(): Unable to initialize RX hardware (-12)
> > > PMD: ixgbevf_dev_reset(): Ixgbe VF reset: Failed to start device.
> > >
> > > Jumping in with GDB, it seems that the rte_rxmbuf_alloc call in
> > > ixgbe_alloc_rx_queue_mbufs returns NULL at iteration 64 out of 2048.
> > > The application has ~500 2MB hugepages, and there's 2GB of free
> > > memory available on top of that.
> > >
> > > Have you seen this before? Any pointer or suggestion for debugging?
> > >
> > > Thanks!
> > >
> > > --
> > > Kind regards,
> > > Luca Boccassi
> > I think the problem is the mbuf occupied by the packets is not released. This
> memory has to be released by the APP, so my patches haven’t covered this.
> Actually an example is needed to show how to use the reset API. I plan to modify
> the testpmd.
> > You may notice this feature is postponed to 16.11. Would you like to wait for
> the new version that will include an example?
> 
> Hi,
> 
> Unfortunately we need the VF reset working sooner than that, so one way or
> the other I'll need to sort it out. Given I've got a use case where this is happening,
> if it can be helpful for you I'm more than happy to help as a guinea pig. If you
> could please give some guidance/guidelines with regards to which API to use to
> sort the mbuf problem, I can try it out and give back some feedback.
> 
> Thanks!
I made a stupid mistake and deleted all my code. So, I have to take some time to rewrite it :(
Attached the example I used to test the reset API. It's modified from the l2fwd example. So you can compare it with l2fwd to see what need to be added.
Hopefully it can help :)

> 
> --
> Kind regards,
> Luca Boccassi