On 07/19/2016 09:16 PM, Brenden Blanco wrote:
Add support for the BPF_PROG_TYPE_XDP hook in mlx4 driver.
In tc/socket bpf programs, helpers linearize skb fragments as needed
when the program touches the packet data. However, in the pursuit of
speed, XDP programs will not be allowed to use these slower functions,
especially if it involves allocating an skb.
Therefore, disallow MTU settings that would produce a multi-fragment
packet that XDP programs would fail to access. Future enhancements could
be done to increase the allowable MTU.
The xdp program is present as a per-ring data structure, but as of yet
it is not possible to set at that granularity through any ndo.
Signed-off-by: Brenden Blanco <bbla...@plumgrid.com>
[...]
struct mlx4_en_bond {
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
index c1b3a9c..6729545 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_rx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_rx.c
@@ -32,6 +32,7 @@
*/
#include <net/busy_poll.h>
+#include <linux/bpf.h>
#include <linux/mlx4/cq.h>
#include <linux/slab.h>
#include <linux/mlx4/qp.h>
@@ -509,6 +510,8 @@ void mlx4_en_destroy_rx_ring(struct mlx4_en_priv *priv,
struct mlx4_en_dev *mdev = priv->mdev;
struct mlx4_en_rx_ring *ring = *pring;
+ if (ring->xdp_prog)
+ bpf_prog_put(ring->xdp_prog);
Would be good if you also make this a READ_ONCE() here. I believe this is the
only other spot in your set that has this 'direct' access (besides xchg() and
READ_ONCE() from mlx4_en_process_rx_cq()). It would be mostly for consistency
and to indicate that there's a more complex synchronization behind it. I'm
mostly
worried that if it's not consistently used, people might copy this and not use
the READ_ONCE() also in other spots where it matters, and thus add hard to find
bugs.
mlx4_free_hwq_res(mdev->dev, &ring->wqres, size * stride + TXBB_SIZE);
vfree(ring->rx_info);
ring->rx_info = NULL;
@@ -743,6 +746,7 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct
mlx4_en_cq *cq, int bud
struct mlx4_en_rx_ring *ring = priv->rx_ring[cq->ring];
struct mlx4_en_rx_alloc *frags;
struct mlx4_en_rx_desc *rx_desc;
+ struct bpf_prog *xdp_prog;
struct sk_buff *skb;
int index;
int nr;
@@ -759,6 +763,8 @@ int mlx4_en_process_rx_cq(struct net_device *dev, struct
mlx4_en_cq *cq, int bud
if (budget <= 0)
return polled;
