From: Björn Töpel <bjorn.topel@xxxxxxxxx>
[ 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@xxxxxxxxx>
Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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))
--
2.19.1
