[PATCH iwl-net 3/5] iavf: prevent VSI corruption when ring params changed during reset

[Aleksandr Loktionov <aleksandr.loktionov@intel.com>]

From: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>

Changing ring parameters via ethtool triggers a VF reset and queue
reconfiguration. If ethtool is called again before the first reset
completes, the second reset races with uninitialised queue state and
can corrupt the VSI resource tree on the PF side.

Return -EAGAIN from iavf_set_ringparam() when the adapter is already
resetting or its queues are disabled.

Fixes: fbb7ddfef253 ("i40evf: core ethtool functionality")
Signed-off-by: Sylwester Dziedziuch <sylwesterx.dziedziuch@intel.com>
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
---
 drivers/net/ethernet/intel/iavf/iavf_ethtool.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
index 1cd1f3f..3909131 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_ethtool.c
@@ -495,6 +495,11 @@ static int iavf_set_ringparam(struct net_device *netdev,
 	if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
 		return -EINVAL;
 
+	if (adapter->state == __IAVF_RESETTING ||
+	    (adapter->state == __IAVF_RUNNING &&
+	     adapter->flags & IAVF_FLAG_QUEUES_DISABLED))
+		return -EAGAIN;
+
 	if (ring->tx_pending > IAVF_MAX_TXD ||
 	    ring->tx_pending < IAVF_MIN_TXD ||
 	    ring->rx_pending > IAVF_MAX_RXD ||
-- 
2.52.0