net/ixgbe: fix VFIO interrupt mapping in PF

When a PF port is bound to VFIO-PIC, only miscellaneous interrupt is mapped to VFIO vector 0 in ixgbe_dev_init( ).
In ixgbe_dev_start(), if previous VFIO interrupt mapping set in ixgbe_dev_init( ) is not cleard, it will fail when calling rte_intr_enable( ) tries to map Rx queue interrupt to other VFIO vectors. This patch clears the VFIO interrupt mappings before setting both miscellaneous and Rx queue interrupt mappings again to avoid failure.

---
 drivers/net/ixgbe/ixgbe_ethdev.c | 9 +++++++++
 1 file changed, 9 insertions(+)

index 9ca5cbc..9030d3d 100644
@@ -2692,6 +2692,15 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
 				     " no intr multiplex");
 	}
 
+	/* When a PF port is bound to VFIO-PCI only miscellaneous interrupt
+	*  is mapped to VFIO vector 0 in ixgbe_dev_init( ).
+	*  If previous VFIO interrupt mapping set in ixgbe_dev_init( ) is
+	*  not cleared, it will fail when following rte_intr_enable( ) tries
+	*  to map Rx queue interrupt to other VFIO vectors.
+	*  So clear uio/vfio intr/evevnfd first to avoid failure.
+	*/
+	rte_intr_disable(intr_handle);
+
 	/* check if rxq interrupt is enabled */
 	if (dev->data->dev_conf.intr_conf.rxq != 0 &&
 	    rte_intr_dp_is_en(intr_handle))

2.7.5

When a PF port is bound to VFIO-PIC, only miscellaneous interrupt is mapped to VFIO vector 0 in ixgbe_dev_init( ).
In ixgbe_dev_start(), if previous VFIO interrupt mapping set in ixgbe_dev_init( ) is not cleard, it will fail when calling rte_intr_enable( ) tries to map Rx queue interrupt to other VFIO vectors. This patch clears the VFIO interrupt mappings before setting both miscellaneous and Rx queue interrupt mappings again to avoid failure.

---
 drivers/net/ixgbe/ixgbe_ethdev.c | 9 +++++++++
 1 file changed, 9 insertions(+)

index 9ca5cbc..5292694 100644
@@ -2692,6 +2692,15 @@ ixgbe_dev_start(struct rte_eth_dev *dev)
 				     " no intr multiplex");
 	}
 
+	/* When a PF port is bound to VFIO-PCI only miscellaneous interrupt
+	 * is mapped to VFIO vector 0 in ixgbe_dev_init( ).
+	 * If previous VFIO interrupt mapping set in ixgbe_dev_init( ) is
+	 * not cleared, it will fail when following rte_intr_enable( ) tries
+	 * to map Rx queue interrupt to other VFIO vectors.
+	 * So clear uio/vfio intr/evevnfd first to avoid failure.
+	 */
+	rte_intr_disable(intr_handle);
+
 	/* check if rxq interrupt is enabled */
 	if (dev->data->dev_conf.intr_conf.rxq != 0 &&
 	    rte_intr_dp_is_en(intr_handle))

2.7.5

Hi Wei,

+1 why we disable interrupt in dev_start twice?

I add this code line to align same style and same action taken in ixgbe VF and i40e VF.
In ixgbe VF or i40e VF, without this line, the initialization of Rx queue interrupt mapping to VFIO-PCI vectors would fail. I have tested it in ixgbe PF port with example/l3fwd-power and
found the interrupt can be initialized successfully and Rx queue can be waked up by incoming packets
no matter whether this line exists or not.
So I decide to reject it now.