net/e1000: fix mailbox interrupt handler

Mailbox interrupt handler only takecare of the PF reset notification,
for other message mbx->ops.read should not be called since it gets
chance to break the foreground VF to PF communication.

Fixes: 316f4f1adc2e ("net/igb: support VF mailbox interrupt for link up/down")
Cc: stable@dpdk.org
Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>
Acked-by: Wei Dai <wei.dai@intel.com>

diff --git a/drivers/net/e1000/igb_ethdev.c b/drivers/net/e1000/igb_ethdev.c
index ae43ade..077e094 100644 (file)
--- a/drivers/net/e1000/igb_ethdev.c
+++ b/drivers/net/e1000/igb_ethdev.c
@@ -2961,13 +2961,17 @@ void igbvf_mbx_process(struct rte_eth_dev *dev)
        struct e1000_mbx_info *mbx = &hw->mbx;
        u32 in_msg = 0;
 
-       if (mbx->ops.read(hw, &in_msg, 1, 0))
-               return;
+       /* peek the message first */
+       in_msg = E1000_READ_REG(hw, E1000_VMBMEM(0));
 
        /* PF reset VF event */
-       if (in_msg == E1000_PF_CONTROL_MSG)
+       if (in_msg == E1000_PF_CONTROL_MSG) {
+               /* dummy mbx read to ack pf */
+               if (mbx->ops.read(hw, &in_msg, 1, 0))
+                       return;
                _rte_eth_dev_callback_process(dev, RTE_ETH_EVENT_INTR_RESET,
                                              NULL);
+       }
 }
 
 static int