[dpdk-dev] [PATCH v2 1/4] net/ixgbevf: unregister irq handler when other interrupts not allowed.

[Tonghao Zhang]

On Fri, Jan 12, 2018 at 4:39 PM, Dai, Wei <wei.dai at intel.com> wrote:
> Hi, Tonghao & Beilei
>
> The issue reported by Tonghao is caused by shortage of igb_uio.
> If you want to use Rx queue interrupt in your DPDK application,
> I suggest use VFIO-PCI to bind NIC port instead of igb_uio.
The performance of igb_uio is better than vfio-pic. So igb_uio is
a better solution. And the PF binded with igb_uio can use the rx queue
interrupt,
because it unregister the irq handler in eal-intr-thread via
rte_intr_callback_unregister.
Then the PF will also not handler the irq (mailbox) from VF, right ?

To support the feature of rx queue interrupt , the PF and VF binded
with igb_uio may unregister the other  irq.

> Currently igb_uio only support single event fd. This fd is triggered by
> both miscellaneous and RX queue interrupt in ixgbe VF.
> But same event fd is added to epoll fd of eal-intr-thread
> and also epoll fd of normal thread for Rx task, this cause the issue.
Yes, it's right

> If VFIO-PCI is used, different event fd for misc and Rx queue are created.
> By the way, your patch also lead to missing of PF to VF reset interrupt.


> So, I am sorry that I can't agree it now.
>
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of
>> xiangxia.m.yue at gmail.com
>> Sent: Friday, January 12, 2018 12:40 AM
>> To: Xing, Beilei <beilei.xing at intel.com>; dev at dpdk.org
>> Cc: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> Subject: [dpdk-dev] [PATCH v2 1/4] net/ixgbevf: unregister irq handler when
>> other interrupts not allowed.
>>
>> From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>>
>> When bind the ixgbe VF (e.g 82599 card) to igb_uio and enable the
>> rx-interrupt, there will be more than one epoll_wait on intr_handle.fd.
>> One is in "eal-intr-thread" thread, and the others are in the thread which call
>> the "rte_epoll_wait". The problem is that sometimes "eal-intr-thread" thread
>> will process the rx interrupt, and then rte_epoll_wait can't get the event
>> anymore, and the packets may be lost.
>>
>> The patch unregister the status interrupt handler in "eal-intr-thread"
>> thread and the ixgbe pf is in the same case.
>>
>> Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> Acked-by: Beilei Xing <beilei.xing at intel.com>
>> ---
>>  drivers/net/ixgbe/ixgbe_ethdev.c | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>>
>> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
>> b/drivers/net/ixgbe/ixgbe_ethdev.c
>> index ff19a56..0e056a2 100644
>> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
>> @@ -5078,6 +5078,15 @@ static int
>> ixgbevf_dev_xstats_get_names(__rte_unused struct rte_eth_dev *dev,
>>       }
>>       ixgbevf_configure_msix(dev);
>>
>> +     if (!rte_intr_allow_others(intr_handle)) {
>> +             rte_intr_callback_unregister(intr_handle,
>> +                                          ixgbevf_dev_interrupt_handler,
>> +                                          dev);
>> +             if (dev->data->dev_conf.intr_conf.lsc != 0)
>> +                     PMD_INIT_LOG(INFO, "lsc won't enable because of"
>> +                                  " no intr multiplex");
>> +     }
>> +
>>       /* When a VF port is bound to VFIO-PCI, only miscellaneous interrupt
>>        * is mapped to VFIO vector 0 in eth_ixgbevf_dev_init( ).
>>        * If previous VFIO interrupt mapping setting in eth_ixgbevf_dev_init( )
>> @@ -5120,6 +5129,12 @@ static int
>> ixgbevf_dev_xstats_get_names(__rte_unused struct rte_eth_dev *dev,
>>
>>       ixgbe_dev_clear_queues(dev);
>>
>> +     if (!rte_intr_allow_others(intr_handle))
>> +             /* resume to the default handler */
>> +             rte_intr_callback_register(intr_handle,
>> +                                        ixgbevf_dev_interrupt_handler,
>> +                                        (void *)dev);
>> +
>>       /* Clean datapath event and queue/vec mapping */
>>       rte_intr_efd_disable(intr_handle);
>>       if (intr_handle->intr_vec != NULL) {
>> --
>> 1.8.3.1
>