From patchwork Mon Nov 6 08:18:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 13446417 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A0BBCFBFA for ; Mon, 6 Nov 2023 08:18:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from out30-99.freemail.mail.aliyun.com (out30-99.freemail.mail.aliyun.com [115.124.30.99]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0BA8B0 for ; Mon, 6 Nov 2023 00:18:37 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046051;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=9;SR=0;TI=SMTPD_---0VvkMuOG_1699258712; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VvkMuOG_1699258712) by smtp.aliyun-inc.com; Mon, 06 Nov 2023 16:18:33 +0800 From: Xuan Zhuo To: netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , virtualization@lists.linux-foundation.org Subject: [PATCH net] virtio_net: fix missing dma unmap for resize Date: Mon, 6 Nov 2023 16:18:32 +0800 Message-Id: <20231106081832.668-1-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Git-Hash: af4189b303fe X-Patchwork-Delegate: kuba@kernel.org For rq, we have three cases getting buffers from virtio core: 1. virtqueue_get_buf{,_ctx} 2. virtqueue_detach_unused_buf 3. callback for virtqueue_resize But in commit 295525e29a5b("virtio_net: merge dma operations when filling mergeable buffers"), I missed the dma unmap for the #3 case. That will leak some memory, because I did not release the pages referred by the unused buffers. If we do such script, we will make the system OOM. while true do ethtool -G ens4 rx 128 ethtool -G ens4 rx 256 free -m done Fixes: 295525e29a5b ("virtio_net: merge dma operations when filling mergeable buffers") Signed-off-by: Xuan Zhuo --- drivers/net/virtio_net.c | 43 ++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d16f592c2061..6423a3a007ce 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -408,6 +408,17 @@ static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) return p; } +static void virtnet_rq_free_buf(struct virtnet_info *vi, + struct receive_queue *rq, void *buf) +{ + if (vi->mergeable_rx_bufs) + put_page(virt_to_head_page(buf)); + else if (vi->big_packets) + give_pages(rq, buf); + else + put_page(virt_to_head_page(buf)); +} + static void enable_delayed_refill(struct virtnet_info *vi) { spin_lock_bh(&vi->refill_lock); @@ -634,17 +645,6 @@ static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx) return buf; } -static void *virtnet_rq_detach_unused_buf(struct receive_queue *rq) -{ - void *buf; - - buf = virtqueue_detach_unused_buf(rq->vq); - if (buf && rq->do_dma) - virtnet_rq_unmap(rq, buf, 0); - - return buf; -} - static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len) { struct virtnet_rq_dma *dma; @@ -1764,7 +1764,7 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, if (unlikely(len < vi->hdr_len + ETH_HLEN)) { pr_debug("%s: short packet %i\n", dev->name, len); DEV_STATS_INC(dev, rx_length_errors); - virtnet_rq_free_unused_buf(rq->vq, buf); + virtnet_rq_free_buf(vi, rq, buf); return; } @@ -4034,14 +4034,15 @@ static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf) static void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf) { struct virtnet_info *vi = vq->vdev->priv; + struct receive_queue *rq; int i = vq2rxq(vq); - if (vi->mergeable_rx_bufs) - put_page(virt_to_head_page(buf)); - else if (vi->big_packets) - give_pages(&vi->rq[i], buf); - else - put_page(virt_to_head_page(buf)); + rq = &vi->rq[i]; + + if (rq->do_dma) + virtnet_rq_unmap(rq, buf, 0); + + virtnet_rq_free_buf(vi, rq, buf); } static void free_unused_bufs(struct virtnet_info *vi) @@ -4057,10 +4058,10 @@ static void free_unused_bufs(struct virtnet_info *vi) } for (i = 0; i < vi->max_queue_pairs; i++) { - struct receive_queue *rq = &vi->rq[i]; + struct virtqueue *vq = vi->rq[i].vq; - while ((buf = virtnet_rq_detach_unused_buf(rq)) != NULL) - virtnet_rq_free_unused_buf(rq->vq, buf); + while ((buf = virtqueue_detach_unused_buf(vq)) != NULL) + virtnet_rq_free_unused_buf(vq, buf); cond_resched(); } }