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

[xiangxia.m.yue@gmail.com]

From: Tonghao Zhang <zhangtonghao@didichuxing.com>

When we 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  sometiems "eal-intr-thread" thread will process the rx interrupt, and
rte_epoll_wait can’t get the event any more, and the packets may be lost.

We should unregister the status interrupt handler in "eal-intr-thread" thread
and the ixgbe is in the same case.

Signed-off-by: Tonghao Zhang <zhangtonghao@didichuxing.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 4339347..5994e55 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -5070,6 +5070,15 @@ 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( )
@@ -5111,6 +5120,12 @@ static int ixgbevf_dev_xstats_get_names(__rte_unused struct rte_eth_dev *dev,
 	dev->data->scattered_rx = 0;
 
 	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);
-- 
1.8.3.1