[dpdk-dev] [PATCH] net/ixgbe: fix mailbox interrupt handler

[Qi Zhang <qi.z.zhang@intel.com>]

Maibox interrupt handler only take about a PF reset notification, for
other message ixgbe_read_mbx should not be called since it get chance
to break the foreground VF to PF communication.
This can be simply repeated by
testpmd>rx_vlan rm all 0

Fixes: 77234603fba0 ("net/ixgbe: support VF mailbox interrupt for link up/down")
Cc: stable@dpdk.org

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
---
 drivers/net/ixgbe/ixgbe_ethdev.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index ff19a56..02121f4 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -8165,13 +8165,17 @@ static void ixgbevf_mbx_process(struct rte_eth_dev *dev)
 	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 	u32 in_msg = 0;
 
-	if (ixgbe_read_mbx(hw, &in_msg, 1, 0))
-		return;
+	/* peek the message first */
+	in_msg = IXGBE_READ_REG(hw, IXGBE_VFMBMEM);
 
 	/* PF reset VF event */
-	if (in_msg == IXGBE_PF_CONTROL_MSG)
+	if (in_msg == IXGBE_PF_CONTROL_MSG) {
+		/* dummy mbx read to ack pf */
+		if (ixgbe_read_mbx(hw, &in_msg, 1, 0))
+			return;
 		_rte_eth_dev_callback_process(dev, RTE_ETH_EVENT_INTR_RESET,
 					      NULL, NULL);
+	}
 }
 
 static int
-- 
2.7.4