From: Daniel Borkmann <daniel@iogearbox•net>
To: Brenden Blanco <bblanco@plumgrid•com>,
davem@davemloft•net, netdev@vger•kernel.org
Cc: Jamal Hadi Salim <jhs@mojatatu•com>,
Saeed Mahameed <saeedm@dev•mellanox.co.il>,
Martin KaFai Lau <kafai@fb•com>,
Jesper Dangaard Brouer <brouer@redhat•com>,
Ari Saha <as754m@att•com>,
Alexei Starovoitov <alexei.starovoitov@gmail•com>,
Or Gerlitz <gerlitz.or@gmail•com>,
john.fastabend@gmail•com, hannes@stressinduktion•org,
Thomas Graf <tgraf@suug•ch>, Tom Herbert <tom@herbertland•com>,
Tariq Toukan <ttoukan.linux@gmail•com>
Subject: Re: [PATCH v10 05/12] net/mlx4_en: add support for fast rx drop bpf program
Date: Wed, 20 Jul 2016 11:07:57 +0200 [thread overview]
Message-ID: <578F3F6D.5000903@iogearbox.net> (raw)
In-Reply-To: <1468955817-10604-6-git-send-email-bblanco@plumgrid.com>
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 <bblanco@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;
next prev parent reply other threads:[~2016-07-20 9:08 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-19 19:16 [PATCH v10 00/12] Add driver bpf hook for early packet drop and forwarding Brenden Blanco
2016-07-19 19:16 ` [PATCH v10 01/12] bpf: add bpf_prog_add api for bulk prog refcnt Brenden Blanco
2016-07-19 21:46 ` Alexei Starovoitov
2016-07-19 19:16 ` [PATCH v10 02/12] bpf: add XDP prog type for early driver filter Brenden Blanco
2016-07-19 21:33 ` Alexei Starovoitov
2016-07-19 19:16 ` [PATCH v10 03/12] net: add ndo to setup/query xdp prog in adapter rx Brenden Blanco
2016-07-19 19:16 ` [PATCH v10 04/12] rtnl: add option for setting link xdp prog Brenden Blanco
2016-07-20 8:38 ` Daniel Borkmann
2016-07-20 17:35 ` Brenden Blanco
2016-07-19 19:16 ` [PATCH v10 05/12] net/mlx4_en: add support for fast rx drop bpf program Brenden Blanco
2016-07-19 21:41 ` Alexei Starovoitov
2016-07-20 9:07 ` Daniel Borkmann [this message]
2016-07-20 17:33 ` Brenden Blanco
2016-07-24 11:56 ` Jesper Dangaard Brouer
2016-07-24 16:57 ` Tom Herbert
2016-07-24 20:34 ` Daniel Borkmann
2016-07-19 19:16 ` [PATCH v10 06/12] Add sample for adding simple drop program to link Brenden Blanco
2016-07-19 21:44 ` Alexei Starovoitov
2016-07-19 19:16 ` [PATCH v10 07/12] net/mlx4_en: add page recycle to prepare rx ring for tx support Brenden Blanco
2016-07-19 21:49 ` Alexei Starovoitov
2016-07-25 7:35 ` Eric Dumazet
2016-08-03 17:45 ` order-0 vs order-N driver allocation. Was: " Alexei Starovoitov
2016-08-04 16:19 ` Jesper Dangaard Brouer
2016-08-05 0:30 ` Alexander Duyck
2016-08-05 3:55 ` Alexei Starovoitov
2016-08-05 15:15 ` Alexander Duyck
2016-08-05 15:33 ` David Laight
2016-08-05 16:00 ` Alexander Duyck
2016-08-05 7:15 ` Eric Dumazet
2016-08-08 2:15 ` Alexei Starovoitov
2016-08-08 8:01 ` Jesper Dangaard Brouer
2016-08-08 18:34 ` Alexei Starovoitov
2016-08-09 12:14 ` Jesper Dangaard Brouer
2016-07-19 19:16 ` [PATCH v10 08/12] bpf: add XDP_TX xdp_action for direct forwarding Brenden Blanco
2016-07-19 21:53 ` Alexei Starovoitov
2016-07-19 19:16 ` [PATCH v10 09/12] net/mlx4_en: break out tx_desc write into separate function Brenden Blanco
2016-07-19 19:16 ` [PATCH v10 10/12] net/mlx4_en: add xdp forwarding and data write support Brenden Blanco
2016-07-19 19:16 ` [PATCH v10 11/12] bpf: enable direct packet data write for xdp progs Brenden Blanco
2016-07-19 21:59 ` Alexei Starovoitov
2016-07-19 19:16 ` [PATCH v10 12/12] bpf: add sample for xdp forwarding and rewrite Brenden Blanco
2016-07-19 22:05 ` Alexei Starovoitov
2016-07-20 17:38 ` Brenden Blanco
2016-07-27 18:25 ` Jesper Dangaard Brouer
2016-08-03 17:01 ` Tom Herbert
2016-08-03 17:11 ` Alexei Starovoitov
2016-08-03 17:29 ` Tom Herbert
2016-08-03 18:29 ` David Miller
2016-08-03 18:29 ` Brenden Blanco
2016-08-03 18:31 ` David Miller
2016-08-03 19:06 ` Tom Herbert
2016-08-03 22:36 ` Alexei Starovoitov
2016-08-03 23:18 ` Daniel Borkmann
2016-07-20 5:09 ` [PATCH v10 00/12] Add driver bpf hook for early packet drop and forwarding David Miller
[not found] ` <6a09ce5d-f902-a576-e44e-8e1e111ae26b@gmail.com>
2016-07-20 14:08 ` Brenden Blanco
2016-07-20 19:14 ` David Miller
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