Commit 8bf5c4ee authored by Jesper Dangaard Brouer's avatar Jesper Dangaard Brouer Committed by Alexei Starovoitov
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tun: setup xdp_rxq_info 



Driver hook points for xdp_rxq_info:
 * reg  : tun_attach
 * unreg: __tun_detach

I've done some manual testing of this tun driver, but I would
appriciate good review and someone else running their use-case tests,
as I'm not 100% sure I understand the tfile->detached semantics.

V2: Removed the skb_array_cleanup() call from V1 by request from Jason Wang.

Cc: Jason Wang <jasowang@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Reviewed-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 27e95e36

drivers/net/tun.c

+23 −1
Original line number Diff line number Diff line
@@ -180,6 +180,7 @@ struct tun_file { 
	struct list_head next;

	struct tun_struct *detached;

	struct skb_array tx_array;

	struct xdp_rxq_info xdp_rxq;

};



struct tun_flow_entry {
@@ -687,8 +688,10 @@ static void __tun_detach(struct tun_file *tfile, bool clean) 
			    tun->dev->reg_state == NETREG_REGISTERED)

				unregister_netdevice(tun->dev);

		}

		if (tun)

		if (tun) {

			skb_array_cleanup(&tfile->tx_array);

			xdp_rxq_info_unreg(&tfile->xdp_rxq);

		}

		sock_put(&tfile->sk);

	}

}
@@ -728,11 +731,13 @@ static void tun_detach_all(struct net_device *dev) 
		tun_napi_del(tun, tfile);

		/* Drop read queue */

		tun_queue_purge(tfile);

		xdp_rxq_info_unreg(&tfile->xdp_rxq);

		sock_put(&tfile->sk);

	}

	list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {

		tun_enable_queue(tfile);

		tun_queue_purge(tfile);

		xdp_rxq_info_unreg(&tfile->xdp_rxq);

		sock_put(&tfile->sk);

	}

	BUG_ON(tun->numdisabled != 0);
@@ -784,6 +789,22 @@ static int tun_attach(struct tun_struct *tun, struct file *file, 


	tfile->queue_index = tun->numqueues;

	tfile->socket.sk->sk_shutdown &= ~RCV_SHUTDOWN;



	if (tfile->detached) {

		/* Re-attach detached tfile, updating XDP queue_index */

		WARN_ON(!xdp_rxq_info_is_reg(&tfile->xdp_rxq));



		if (tfile->xdp_rxq.queue_index    != tfile->queue_index)

			tfile->xdp_rxq.queue_index = tfile->queue_index;

	} else {

		/* Setup XDP RX-queue info, for new tfile getting attached */

		err = xdp_rxq_info_reg(&tfile->xdp_rxq,

				       tun->dev, tfile->queue_index);

		if (err < 0)

			goto out;

		err = 0;

	}



	rcu_assign_pointer(tfile->tun, tun);

	rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile);

	tun->numqueues++;
@@ -1508,6 +1529,7 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, 
		xdp.data = buf + pad;

		xdp_set_data_meta_invalid(&xdp);

		xdp.data_end = xdp.data + len;

		xdp.rxq = &tfile->xdp_rxq;

		orig_data = xdp.data;

		act = bpf_prog_run_xdp(xdp_prog, &xdp);

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