From patchwork Wed Jun 29 06:56:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 12899499 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9CABCCA486 for ; Wed, 29 Jun 2022 07:01:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232496AbiF2HB6 (ORCPT ); Wed, 29 Jun 2022 03:01:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40388 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232876AbiF2G74 (ORCPT ); Wed, 29 Jun 2022 02:59:56 -0400 Received: from out30-42.freemail.mail.aliyun.com (out30-42.freemail.mail.aliyun.com [115.124.30.42]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB69B36B55; Tue, 28 Jun 2022 23:58:30 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=37;SR=0;TI=SMTPD_---0VHmYPBX_1656485900; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VHmYPBX_1656485900) by smtp.aliyun-inc.com; Wed, 29 Jun 2022 14:58:21 +0800 From: Xuan Zhuo To: virtualization@lists.linux-foundation.org Cc: Richard Weinberger , Anton Ivanov , Johannes Berg , "Michael S. Tsirkin" , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Eric Farman , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Xuan Zhuo , Vincent Whitchurch , linux-um@lists.infradead.org, netdev@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, bpf@vger.kernel.org, kangjie.xu@linux.alibaba.com Subject: [PATCH v11 39/40] virtio_net: support tx queue resize Date: Wed, 29 Jun 2022 14:56:55 +0800 Message-Id: <20220629065656.54420-40-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.31.0 In-Reply-To: <20220629065656.54420-1-xuanzhuo@linux.alibaba.com> References: <20220629065656.54420-1-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 X-Git-Hash: 3fdaf102dd89 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org This patch implements the resize function of the tx queues. Based on this function, it is possible to modify the ring num of the queue. Signed-off-by: Xuan Zhuo --- drivers/net/virtio_net.c | 48 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6ab16fd193e5..fd358462f802 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -135,6 +135,9 @@ struct send_queue { struct virtnet_sq_stats stats; struct napi_struct napi; + + /* Record whether sq is in reset state. */ + bool reset; }; /* Internal representation of a receive virtqueue */ @@ -279,6 +282,7 @@ struct padded_vnet_hdr { }; static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf); +static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); static bool is_xdp_frame(void *ptr) { @@ -1603,6 +1607,11 @@ static void virtnet_poll_cleantx(struct receive_queue *rq) return; if (__netif_tx_trylock(txq)) { + if (READ_ONCE(sq->reset)) { + __netif_tx_unlock(txq); + return; + } + do { virtqueue_disable_cb(sq->vq); free_old_xmit_skbs(sq, true); @@ -1868,6 +1877,45 @@ static int virtnet_rx_resize(struct virtnet_info *vi, return err; } +static int virtnet_tx_resize(struct virtnet_info *vi, + struct send_queue *sq, u32 ring_num) +{ + struct netdev_queue *txq; + int err, qindex; + + qindex = sq - vi->sq; + + virtnet_napi_tx_disable(&sq->napi); + + txq = netdev_get_tx_queue(vi->dev, qindex); + + /* 1. wait all ximt complete + * 2. fix the race of netif_stop_subqueue() vs netif_start_subqueue() + */ + __netif_tx_lock_bh(txq); + + /* Prevent rx poll from accessing sq. */ + WRITE_ONCE(sq->reset, true); + + /* Prevent the upper layer from trying to send packets. */ + netif_stop_subqueue(vi->dev, qindex); + + __netif_tx_unlock_bh(txq); + + err = virtqueue_resize(sq->vq, ring_num, virtnet_sq_free_unused_buf); + if (err) + netdev_err(vi->dev, "resize tx fail: tx queue index: %d err: %d\n", qindex, err); + + /* Memory barrier before set reset and start subqueue. */ + smp_mb(); + + WRITE_ONCE(sq->reset, false); + netif_tx_wake_queue(txq); + + virtnet_napi_tx_enable(vi, sq->vq, &sq->napi); + return err; +} + /* * Send command via the control virtqueue and check status. Commands * supported by the hypervisor, as indicated by feature bits, should