6.12-stable review patch. If anyone has any objections, please let me know.
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From: Joshua Washington joshwash@google.com
commit ff7c2dea9dd1a436fc79d6273adffdcc4a7ffea3 upstream.
In GVE, dedicated XDP queues only exist when an XDP program is installed and the interface is up. As such, the NDO XDP XMIT callback should return early if either of these conditions are false.
In the case of no loaded XDP program, priv->num_xdp_queues=0 which can cause a divide-by-zero error, and in the case of interface down, num_xdp_queues remains untouched to persist XDP queue count for the next interface up, but the TX pointer itself would be NULL.
The XDP xmit callback also needs to synchronize with a device transitioning from open to close. This synchronization will happen via the GVE_PRIV_FLAGS_NAPI_ENABLED bit along with a synchronize_net() call, which waits for any RCU critical sections at call-time to complete.
Fixes: 39a7f4aa3e4a ("gve: Add XDP REDIRECT support for GQI-QPL format") Cc: stable@vger.kernel.org Signed-off-by: Joshua Washington joshwash@google.com Signed-off-by: Praveen Kaligineedi pkaligineedi@google.com Reviewed-by: Praveen Kaligineedi pkaligineedi@google.com Reviewed-by: Shailend Chand shailend@google.com Reviewed-by: Willem de Bruijn willemb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/google/gve/gve_main.c | 3 +++ drivers/net/ethernet/google/gve/gve_tx.c | 5 ++++- 2 files changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/google/gve/gve_main.c +++ b/drivers/net/ethernet/google/gve/gve_main.c @@ -1904,6 +1904,9 @@ static void gve_turndown(struct gve_priv
gve_clear_napi_enabled(priv); gve_clear_report_stats(priv); + + /* Make sure that all traffic is finished processing. */ + synchronize_net(); }
static void gve_turnup(struct gve_priv *priv) --- a/drivers/net/ethernet/google/gve/gve_tx.c +++ b/drivers/net/ethernet/google/gve/gve_tx.c @@ -837,9 +837,12 @@ int gve_xdp_xmit(struct net_device *dev, struct gve_tx_ring *tx; int i, err = 0, qid;
- if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK)) + if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK) || !priv->xdp_prog) return -EINVAL;
+ if (!gve_get_napi_enabled(priv)) + return -ENETDOWN; + qid = gve_xdp_tx_queue_id(priv, smp_processor_id() % priv->num_xdp_queues);