When mana_attach() fails during ethtool ring size or channel count changes, the port is left in a broken state with no recovery mechanism, requiring manual intervention to bring the port back up.
On VM SKUs without a netvsc fallback interface, this results in complete loss of network connectivity to the VM. Fix by scheduling queue_reset_work when mana_attach() fails. The preceding patch ensures mana_detach() always completes its full teardown (netif_device_detach + cleanup), so the reset handler's mana_detach() takes the "already detached" early return, preserving port_st_save for a successful mana_attach() recovery. When mana_attach() fails, choose retry values that maximize recovery chances: if the operation was an increase, fall back to the previous working values; if it was a decrease but still above default, fall back to defaults; otherwise use the minimum supported values. Reviewed-by: Haiyang Zhang <[email protected]> Tested-by: Aditya Garg <[email protected]> Signed-off-by: Dipayaan Roy <[email protected]> --- .../ethernet/microsoft/mana/mana_ethtool.c | 48 +++++++++++++++++-- 1 file changed, 45 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c index f77509818d07..71e69d5a9a04 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_ethtool.c +++ b/drivers/net/ethernet/microsoft/mana/mana_ethtool.c @@ -646,6 +646,7 @@ static int mana_set_channels(struct net_device *ndev, struct mana_port_context *apc = netdev_priv(ndev); unsigned int new_count = channels->combined_count; unsigned int old_count = apc->num_queues; + bool schedule_port_reset = false; int err; /* Set channel_changing to block RDMA from grabbing the vport @@ -675,8 +676,19 @@ static int mana_set_channels(struct net_device *ndev, apc->num_queues = new_count; err = mana_attach(ndev); if (err) { - apc->num_queues = old_count; netdev_err(ndev, "mana_attach failed: %d\n", err); + + /* Choose a retry queue count that maximizes recovery + * chances in the reset work handler. + */ + if (old_count < new_count) + apc->num_queues = old_count; + else if (new_count > MANA_DEF_NUM_QUEUES) + apc->num_queues = MANA_DEF_NUM_QUEUES; + else + apc->num_queues = 1; + + schedule_port_reset = true; } out: @@ -685,6 +697,11 @@ static int mana_set_channels(struct net_device *ndev, mutex_lock(&apc->vport_mutex); apc->channel_changing = false; mutex_unlock(&apc->vport_mutex); + + if (schedule_port_reset) + queue_work(apc->ac->per_port_queue_reset_wq, + &apc->queue_reset_work); + return err; } @@ -707,6 +724,7 @@ static int mana_set_ringparam(struct net_device *ndev, struct netlink_ext_ack *extack) { struct mana_port_context *apc = netdev_priv(ndev); + bool schedule_port_reset = false; u32 new_tx, new_rx; u32 old_tx, old_rx; int err; @@ -752,11 +770,35 @@ static int mana_set_ringparam(struct net_device *ndev, err = mana_attach(ndev); if (err) { netdev_err(ndev, "mana_attach failed: %d\n", err); - apc->tx_queue_size = old_tx; - apc->rx_queue_size = old_rx; + NL_SET_ERR_MSG_FMT(extack, "failed to change ring params: %d", + err); + + /* Choose retry ring sizes that maximize recovery + * chances in the reset work handler. Handle RX and + * TX independently. + */ + if (old_rx < new_rx) + apc->rx_queue_size = old_rx; + else if (new_rx > DEF_RX_BUFFERS_PER_QUEUE) + apc->rx_queue_size = DEF_RX_BUFFERS_PER_QUEUE; + else + apc->rx_queue_size = MIN_RX_BUFFERS_PER_QUEUE; + + if (old_tx < new_tx) + apc->tx_queue_size = old_tx; + else if (new_tx > DEF_TX_BUFFERS_PER_QUEUE) + apc->tx_queue_size = DEF_TX_BUFFERS_PER_QUEUE; + else + apc->tx_queue_size = MIN_TX_BUFFERS_PER_QUEUE; + + schedule_port_reset = true; } out: mana_pre_dealloc_rxbufs(apc); + + if (schedule_port_reset) + queue_work(apc->ac->per_port_queue_reset_wq, + &apc->queue_reset_work); return err; } -- 2.43.0
