[PATCH v3 1/6] net/ixgbevf: unregister irq handler when other interrupts not allowed.

[xiangxia.m.yue@gmail.com]

From: Tonghao Zhang <xiangxia.m.yue@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@gmail.com>
Acked-by: Beilei Xing <beilei.xing@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