On 2017年12月13日 19:20, Jesper Dangaard Brouer wrote:
Driver hook points for xdp_rxq_info: * init+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. Cc: Jason Wang <jasow...@redhat.com> Cc: "Michael S. Tsirkin" <m...@redhat.com> Cc: Willem de Bruijn <will...@google.com> Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com> --- drivers/net/tun.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e367d6310353..f1df08c2c541 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -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 +731,15 @@ static void tun_detach_all(struct net_device *dev) tun_napi_del(tun, tfile); /* Drop read queue */ tun_queue_purge(tfile); + skb_array_cleanup(&tfile->tx_array);
Looks like this is unnecessary, skb array will be cleaned up only when fd is closed otherwise there will be a double free.
Other looks good. Thanks
+ 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); + skb_array_cleanup(&tfile->tx_array); + xdp_rxq_info_unreg(&tfile->xdp_rxq); sock_put(&tfile->sk); } BUG_ON(tun->numdisabled != 0); @@ -784,6 +791,21 @@ 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 */ + xdp_rxq_info_init(&tfile->xdp_rxq); + tfile->xdp_rxq.dev = tun->dev; + tfile->xdp_rxq.queue_index = tfile->queue_index; + xdp_rxq_info_reg(&tfile->xdp_rxq); + } + rcu_assign_pointer(tfile->tun, tun); rcu_assign_pointer(tun->tfiles[tun->numqueues], tfile); tun->numqueues++; @@ -1508,6 +1530,7 @@ 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);
