From: Björn Töpel bjorn.topel@intel.com
[ Upstream commit 59eb2a884f5380011179acc4662fc2cc2d850454 ]
When the driver clears the XDP xmit ring due to re-configuration or teardown, in-progress ndo_xdp_xmit must be taken into consideration.
The ndo_xdp_xmit function is typically called from a NAPI context that the driver does not control. Therefore, we must be careful not to clear the XDP ring, while the call is on-going. This patch adds a synchronize_rcu() to wait for napi(s) (preempt-disable regions and softirqs), prior clearing the queue. Further, the __I40E_CONFIG_BUSY flag is checked in the ndo_xdp_xmit implementation to avoid touching the XDP xmit queue during re-configuration.
Fixes: d9314c474d4f ("i40e: add support for XDP_REDIRECT") Fixes: 123cecd427b6 ("i40e: added queue pair disable/enable functions") Reported-by: Maciej Fijalkowski maciej.fijalkowski@intel.com Signed-off-by: Björn Töpel bjorn.topel@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/i40e/i40e_main.c | 14 ++++++++++++-- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 4 +++- 2 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 89a072b5ce6c..393647153857 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -6729,8 +6729,13 @@ void i40e_down(struct i40e_vsi *vsi)
for (i = 0; i < vsi->num_queue_pairs; i++) { i40e_clean_tx_ring(vsi->tx_rings[i]); - if (i40e_enabled_xdp_vsi(vsi)) + if (i40e_enabled_xdp_vsi(vsi)) { + /* Make sure that in-progress ndo_xdp_xmit + * calls are completed. + */ + synchronize_rcu(); i40e_clean_tx_ring(vsi->xdp_rings[i]); + } i40e_clean_rx_ring(vsi->rx_rings[i]); }
@@ -11966,8 +11971,13 @@ static void i40e_queue_pair_reset_stats(struct i40e_vsi *vsi, int queue_pair) static void i40e_queue_pair_clean_rings(struct i40e_vsi *vsi, int queue_pair) { i40e_clean_tx_ring(vsi->tx_rings[queue_pair]); - if (i40e_enabled_xdp_vsi(vsi)) + if (i40e_enabled_xdp_vsi(vsi)) { + /* Make sure that in-progress ndo_xdp_xmit calls are + * completed. + */ + synchronize_rcu(); i40e_clean_tx_ring(vsi->xdp_rings[queue_pair]); + } i40e_clean_rx_ring(vsi->rx_rings[queue_pair]); }
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index d0a95424ce58..48a0d8a53895 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -3708,6 +3708,7 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, struct i40e_netdev_priv *np = netdev_priv(dev); unsigned int queue_index = smp_processor_id(); struct i40e_vsi *vsi = np->vsi; + struct i40e_pf *pf = vsi->back; struct i40e_ring *xdp_ring; int drops = 0; int i; @@ -3715,7 +3716,8 @@ int i40e_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames, if (test_bit(__I40E_VSI_DOWN, vsi->state)) return -ENETDOWN;
- if (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs) + if (!i40e_enabled_xdp_vsi(vsi) || queue_index >= vsi->num_queue_pairs || + test_bit(__I40E_CONFIG_BUSY, pf->state)) return -ENXIO;
if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))