Re: [dpdk-dev] [PATCH 0/2] support mailbox interruption on ixgbe/igb VF

[Luca Boccassi <lboccass@Brocade.com>]

On Tue, 2016-05-24 at 14:06 +0800, Wenzhuo Lu wrote:
> This patch set addes the support of the mailbox interruption on VF.
> So, VF can receice the messges for physical link down/up.
> 
> PS: This patch set is splitted from a previous patch set, *automatic
> link recovery on ixgbe/igb VF*.
> 
> Wenzhuo Lu (2):
>   ixgbe: VF supports mailbox interruption for PF link up/down
>   igb: VF supports mailbox interruption for PF link up/down
> 
>  doc/guides/rel_notes/release_16_07.rst |   6 ++
>  drivers/net/e1000/igb_ethdev.c         | 159 +++++++++++++++++++++++++++++++++
>  drivers/net/ixgbe/ixgbe_ethdev.c       |  85 +++++++++++++++++-
>  3 files changed, 247 insertions(+), 3 deletions(-)
> 

Hi,

After backporting these patches to 16.04 or 2.2, we get a segmentation
fault when using interface bonding when the interfaces go down. The
scenario is:

- Host has a X540-AT2 10gb card using the ixgbe driver, 2 VFs are
created and passes to the qemu/kvm guest VM via libvirt
- Guest creates a bonded link using the 2 VFs
- Host sets the VFs state to down via ip link
- Guess DPDK app segfaults

Backtrace:

#0  0x0000000000000000 in ?? ()
No symbol table info available.
#1  0x00007ffff5003957 in bond_ethdev_slave_link_status_change_monitor (
    cb_arg=0x727748 <rte_eth_devices@@DPDK_2.2+4168>)
    at /usr/src/packages/BUILD/drivers/net/bonding/rte_eth_bond_pmd.c:1938
        internals = 0x7fffeb8f5ec0
        i = 0
        polling_slave_found = 0
#2  0x00007ffff68ea88c in eal_alarm_callback (hdl=<optimized out>, arg=<optimized out>)
    at /usr/src/packages/BUILD/lib/librte_eal/linuxapp/eal/eal_alarm.c:120
        now = {tv_sec = 356, tv_nsec = 551082574}
        ap = 0x7fffebc22380
#3  0x00007ffff68e926d in eal_intr_process_interrupts (nfds=<optimized out>, events=<optimized out>)
    at /usr/src/packages/BUILD/lib/librte_eal/linuxapp/eal/eal_interrupts.c:752
        bytes_read = <optimized out>
        buf = {uio_intr_count = 1, vfio_intr_count = 1, timerfd_num = 1, 
          charbuf = "\001\000\000\000\000\000\000\000D\260~\363\377\177\000"}
        n = 0
        src = 0x7fffeb8d2640
        cb = 0x7fffeb8d2d80
        next = <optimized out>
        active_cb = <optimized out>
#4  eal_intr_handle_interrupts (totalfds=<optimized out>, pfd=12)
    at /usr/src/packages/BUILD/lib/librte_eal/linuxapp/eal/eal_interrupts.c:800
        events = 0x7fffefb1ba20
        nfds = 1
#5  eal_intr_thread_main (arg=<optimized out>)
    at /usr/src/packages/BUILD/lib/librte_eal/linuxapp/eal/eal_interrupts.c:870
        pipe_event = {events = 3, data = {ptr = 0x6, fd = 6, u32 = 6, u64 = 6}}
        src = <optimized out>
        numfds = <optimized out>
        pfd = 12
        ev = {events = 3, data = {ptr = 0xf7df02e500000005, fd = 5, u32 = 5, 
            u64 = 17860997829745442821}}
        __func__ = "eal_intr_thread_main"
#6  0x00007ffff37eb0a4 in start_thread (arg=0x7fffefb3c700) at pthread_create.c:309
        __res = <optimized out>
        pd = 0x7fffefb3c700
        now = <optimized out>
        unwind_buf = {cancel_jmp_buf = {{jmp_buf = {140737214924544, 2510814068564645188, 1, 
                140737354125408, 140737336548072, 140737214924544, -2510779380161489596, 
                -2510806361332034236}, mask_was_saved = 0}}, priv = {pad = {0x0, 0x0, 0x0, 0x0}, 
            data = {prev = 0x0, cleanup = 0x0, canceltype = 0}}}
        not_first_call = <optimized out>
        pagesize_m1 = <optimized out>
        sp = <optimized out>
        freesize = <optimized out>
        __PRETTY_FUNCTION__ = "start_thread"
#7  0x00007ffff1b8287d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111

It dies in this bit:

/* Update slave link status */
(*slave_ethdev->dev_ops->link_update)(slave_ethdev,
	internals->slaves[i].link_status_wait_to_complete);

(gdb) print rte_eth_devices[internals->slaves[i].port_id]
$7 = {rx_pkt_burst = 0x0, tx_pkt_burst = 0x0, data = 0x0, driver = 0x0, dev_ops = 0x0, {pci_dev = 0x0, 
    vmbus_dev = 0x0}, link_intr_cbs = {tqh_first = 0x0, tqh_last = 0x0}, post_rx_burst_cbs = {
    0x0 <repeats 256 times>}, pre_tx_burst_cbs = {0x0 <repeats 256 times>}, attached = 0 '\000', 
  dev_type = RTE_ETH_DEV_UNKNOWN}

I'm assuming it's not a simply matter of checking the dev_type or for
nulls. Do you have any suggestions/insight? I'm delving into the issue,
but it's the first time I look at the bonding code so any help or
pointers would be greatly appreciated.

Note that I also tried to backport the additional patches for reset that
are currently under review on top of these, but there's no difference.
But I have not yet used the new reset API in our app though.

Thanks!

-- 
Kind regards,
Luca Boccassi