From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 24F64366DB2 for ; Thu, 5 Mar 2026 12:03:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772712225; cv=none; b=mzHGfm/ANBZAH6IrznTA2wWqRSZ9N2bVQeomrhTcZ0KQK/ycMh3Oj7MlJoMJ+xCyH+MHP3hoi5adCg6hNSUjdpgOrYEJJyPceDfax8JOcvkbhhNnOh3KoUIs3Ze2tyG1MAx57ZoX2vmroIrk0s/ME3camq7Ivyi4QfFTsQxYU1Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772712225; c=relaxed/simple; bh=Wx3AaFrtqOiu9PGQ7P0HchX8BTXIVrjnzqVITF2pMZk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=i/EUBv2bKX0v54d9xc74TPcnHT12cl36gdooBqOVIDp5vh/u5JdhHMATKBP+tCbwyl/l1zDcYA5f2fUqnrUtXRxWy/dXcnSwZk8mg6co24x9ZBH1cFJ8hGZDB8Q9tO65B6bbEsL1zS1Ncnn7X1Iuy70Jz0/ajePFEmFnLYx1qKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=QYH/qDC4; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=CIIEczCF; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="QYH/qDC4"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="CIIEczCF" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1772712221; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tCnysCynxr7A2J5nRy8ilWqWGBCIJ/AwT186rb+PFlE=; b=QYH/qDC4yEWJ4u7k5FbG5fxVyb9mjPFg3PG4HZ6V8r5P6Ec+ZfY8KEufqXDxAzwnB6AjfR Avg2m6FWfP/dojnk4IeSTcgYL3bFxOqpmWJgVUdBCxvUrsbu+rEkGvK0DXlyhMpCEhJB6m uSbv6aUbQWBLDw8GFyuoMDY+SXmjMMU= Received: from mail-wr1-f71.google.com (mail-wr1-f71.google.com [209.85.221.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-608-YFHMTLpNOp2il_E3TKMl0Q-1; Thu, 05 Mar 2026 07:03:40 -0500 X-MC-Unique: YFHMTLpNOp2il_E3TKMl0Q-1 X-Mimecast-MFC-AGG-ID: YFHMTLpNOp2il_E3TKMl0Q_1772712219 Received: by mail-wr1-f71.google.com with SMTP id ffacd0b85a97d-439b50dfca1so3234300f8f.0 for ; Thu, 05 Mar 2026 04:03:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1772712219; x=1773317019; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=tCnysCynxr7A2J5nRy8ilWqWGBCIJ/AwT186rb+PFlE=; b=CIIEczCFVaBleqI1+uKL118xpnVWJuRWXrb+D0QwBK843G6T1DbEvBUm8iYLInXO24 jq55Fcd5rNp8TJkuubaa/c60HuWP0HIgWu/OwgHKa25/7k/aC0R5ak+8PHKvuRvnrAUJ nUsI80m1ZJsJ4XBGCs3kGOODSnze9vILfPMAV/O4+u0FoikUZApeCpFgPNJ5FWcyWQJu ui0ToY/RL5k3RoAFVs7w3aGp1sWMcvqzkK3l4SHzjQRGho7UJ50WauJZ4/s91TotnJ9F 6rZkyN+PIel/8TwUFbjGlvUPQb5hX1jd41JJKkSdvianLft5cYDRpDLp+4SX9NUQdf7H Me/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772712219; x=1773317019; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=tCnysCynxr7A2J5nRy8ilWqWGBCIJ/AwT186rb+PFlE=; b=uMFvxBnAOkeuUCwtkl8JQVrO60khE4IHeM7rN/Ru8qLP5RW1Jt3MxVGdWMxDuLuk0E IqpZ6XXzjGvf/htuLYi6rZvB4kgpDKsk6x9uMqymc1ItqUPvAFgXy1dQll9u4QSf9CTS OvX4s+TLTnoiISYeH6plj3jMhyQucjS4f9YjJgkIOTrTOXG4BEobtiNMAxVI6FUOLE0S TOLoVJn85cTMaH8nRy9CLHOU7h2OscngHMKDJ+Y7Qru2Kj1GOEkLwyQ0mDS4uZ2jU4jZ 2wf+ibLMylKZ9ewMttFE89ltZYXLnG/krjZUBZvmsF4DvqPYYUluZ6+8A/UfTNZb4hUe uanA== X-Forwarded-Encrypted: i=1; AJvYcCUTzy++ShmFAYGWDWYpR0Wxq5HhBrjcvhENS04BFwW+ht0gUUhCj8zJDz8COq9Z2KboMyiZ+qlVVbAR20E=@vger.kernel.org X-Gm-Message-State: AOJu0YzpvDFvYIH3DMO4L0vSrYQUwYiQMlpXHtMWi3z5ziovnOIbggyo Mfl9ct3K/rQBKI/iQ9Z6kIoURxwaOjUFqB/zTHl86NerW8ULG54OuSURtvvtpSLa8t21vsghe2h fUAL2XgTWhfZzFdHXouju9WCWq02VqrtGr25T+WGkiApsfMgmnKRy4/5L5H5Z4dchhg== X-Gm-Gg: ATEYQzyfNCR+4fCYFLidLLQQnYFO5cPguD1l5pUAzAgdMCoyJ1GVRoSvSUrovZebYnn JWJuqNG/rfemlYQIlj9YKg0KNYCQ6BZbnhIJFhErbgplwUQiazpjDgFJa3r9IG+QfTUCpqVrCoa u8vBgg6qte7PxDV9nFjZtbBHHb8OgQVfDU+qlaY++OiwwIf/RxZZZX3fD4K/eiEI0Zyw1Zk+/xj XnlptSwR11rBqgKfkFYzHxSzajMyHE5LkhUToWdHyJKRX/1DBueszw0yBZx8dZFgEGb/SyQbhlJ YwHz7SkL5f7+1xR6SabGIWnSmNhOs8IHOwwdyugaDNKz7sRXzdve8Zpjdd5WZYqjW1Fsh5aK0Lv J4Hbxv+0H0TYDsaUAs/BM8WLAoA== X-Received: by 2002:a05:6000:2902:b0:435:e3bd:5838 with SMTP id ffacd0b85a97d-439c7f8f92emr10502695f8f.25.1772712218296; Thu, 05 Mar 2026 04:03:38 -0800 (PST) X-Received: by 2002:a05:6000:2902:b0:435:e3bd:5838 with SMTP id ffacd0b85a97d-439c7f8f92emr10502605f8f.25.1772712217535; Thu, 05 Mar 2026 04:03:37 -0800 (PST) Received: from [192.168.88.32] ([212.105.149.216]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-439c4489279sm19569460f8f.20.2026.03.05.04.03.35 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 05 Mar 2026 04:03:36 -0800 (PST) Message-ID: Date: Thu, 5 Mar 2026 13:03:34 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v10] virtio_net: add page_pool support for buffer allocation To: Vishwanath Seshagiri , "Michael S . Tsirkin" , Jason Wang Cc: Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Andrew Lunn , "David S . Miller" , Eric Dumazet , Jakub Kicinski , David Wei , Matteo Croce , Ilias Apalodimas , netdev@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, kernel-team@meta.com References: <20260303074253.3449987-1-vishs@meta.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20260303074253.3449987-1-vishs@meta.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 3/3/26 8:42 AM, Vishwanath Seshagiri wrote: > Use page_pool for RX buffer allocation in mergeable and small buffer > modes to enable page recycling and avoid repeated page allocator calls. > skb_mark_for_recycle() enables page reuse in the network stack. > > Big packets mode is unchanged because it uses page->private for linked > list chaining of multiple pages per buffer, which conflicts with > page_pool's internal use of page->private. > > Implement conditional DMA premapping using virtqueue_dma_dev(): > - When non-NULL (vhost, virtio-pci): use PP_FLAG_DMA_MAP with page_pool > handling DMA mapping, submit via virtqueue_add_inbuf_premapped() > - When NULL (VDUSE, direct physical): page_pool handles allocation only, > submit via virtqueue_add_inbuf_ctx() > > This preserves the DMA premapping optimization from commit 31f3cd4e5756b > ("virtio-net: rq submits premapped per-buffer") while adding page_pool > support as a prerequisite for future zero-copy features (devmem TCP, > io_uring ZCRX). > > Page pools are created in probe and destroyed in remove (not open/close), > following existing driver behavior where RX buffers remain in virtqueues > across interface state changes. > > Signed-off-by: Vishwanath Seshagiri > --- > Changes in v10: > - add_recvbuf_small: use alloc_len to avoid clobbering len (Michael S. Tsirkin) > - v9: > https://lore.kernel.org/virtualization/20260302041005.1627210-1-vishs@meta.com/ > > Changes in v9: > - Fix virtnet_skb_append_frag() for XSK callers (Michael S. Tsirkin) > - v8: > https://lore.kernel.org/virtualization/e824c5a3-cfe0-4d11-958f-c3ec82d11d37@meta.com/ > > Changes in v8: > - Remove virtnet_no_page_pool() helper, replace with direct !rq->page_pool > checks or inlined conditions (Xuan Zhuo) > - Extract virtnet_rq_submit() helper to consolidate DMA/non-DMA buffer > submission in add_recvbuf_small() and add_recvbuf_mergeable() > - Add skb_mark_for_recycle(nskb) for overflow frag_list skbs in > virtnet_skb_append_frag() to ensure page_pool pages are returned to > the pool instead of freed via put_page() > - Rebase on net-next (kzalloc_objs API) > - v7: > https://lore.kernel.org/virtualization/20260210014305.3236342-1-vishs@meta.com/ > > Changes in v7: > - Replace virtnet_put_page() helper with direct page_pool_put_page() > calls (Xuan Zhuo) > - Add virtnet_no_page_pool() helper to consolidate big_packets mode check > (Michael S. Tsirkin) > - Add DMA sync_for_cpu for subsequent buffers in xdp_linearize_page() when > use_page_pool_dma is set (Michael S. Tsirkin) > - Remove unused pp_params.dev assignment in non-DMA path > - Add page pool recreation in virtnet_restore_up() for freeze/restore support (Chris Mason's > Review Prompt) > - v6: > https://lore.kernel.org/virtualization/20260208175410.1910001-1-vishs@meta.com/ > > Changes in v6: > - Drop page_pool_frag_offset_add() helper and switch to page_pool_alloc_va(); > page_pool_alloc_netmem() already handles internal fragmentation internally > (Jakub Kicinski) > - v5: > https://lore.kernel.org/virtualization/20260206002715.1885869-1-vishs@meta.com/ > > Benchmark results: > > Configuration: pktgen TX -> tap -> vhost-net | virtio-net RX -> XDP_DROP > > Small packets (64 bytes, mrg_rxbuf=off): > 1Q: 853,493 -> 868,923 pps (+1.8%) > 2Q: 1,655,793 -> 1,696,707 pps (+2.5%) > 4Q: 3,143,375 -> 3,302,511 pps (+5.1%) > 8Q: 6,082,590 -> 6,156,894 pps (+1.2%) > > Mergeable RX (64 bytes): > 1Q: 766,168 -> 814,493 pps (+6.3%) > 2Q: 1,384,871 -> 1,670,639 pps (+20.6%) > 4Q: 2,773,081 -> 3,080,574 pps (+11.1%) > 8Q: 5,600,615 -> 6,043,891 pps (+7.9%) > > Mergeable RX (1500 bytes): > 1Q: 741,579 -> 785,442 pps (+5.9%) > 2Q: 1,310,043 -> 1,534,554 pps (+17.1%) > 4Q: 2,748,700 -> 2,890,582 pps (+5.2%) > 8Q: 5,348,589 -> 5,618,664 pps (+5.0%) > > drivers/net/Kconfig | 1 + > drivers/net/virtio_net.c | 466 ++++++++++++++++++++------------------- > 2 files changed, 237 insertions(+), 230 deletions(-) > > diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig > index 17108c359216..b2fd90466bab 100644 > --- a/drivers/net/Kconfig > +++ b/drivers/net/Kconfig > @@ -452,6 +452,7 @@ config VIRTIO_NET > depends on VIRTIO > select NET_FAILOVER > select DIMLIB > + select PAGE_POOL > help > This is the virtual network driver for virtio. It can be used with > QEMU based VMMs (like KVM or Xen). Say Y or M. > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 72d6a9c6a5a2..d722031604bf 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > > static int napi_weight = NAPI_POLL_WEIGHT; > module_param(napi_weight, int, 0444); > @@ -290,14 +291,6 @@ struct virtnet_interrupt_coalesce { > u32 max_usecs; > }; > > -/* The dma information of pages allocated at a time. */ > -struct virtnet_rq_dma { > - dma_addr_t addr; > - u32 ref; > - u16 len; > - u16 need_sync; > -}; > - > /* Internal representation of a send virtqueue */ > struct send_queue { > /* Virtqueue associated with this send _queue */ > @@ -356,8 +349,10 @@ struct receive_queue { > /* Average packet length for mergeable receive buffers. */ > struct ewma_pkt_len mrg_avg_pkt_len; > > - /* Page frag for packet buffer allocation. */ > - struct page_frag alloc_frag; > + struct page_pool *page_pool; > + > + /* True if page_pool handles DMA mapping via PP_FLAG_DMA_MAP */ > + bool use_page_pool_dma; > > /* RX: fragments + linear part + virtio header */ > struct scatterlist sg[MAX_SKB_FRAGS + 2]; > @@ -370,9 +365,6 @@ struct receive_queue { > > struct xdp_rxq_info xdp_rxq; > > - /* Record the last dma info to free after new pages is allocated. */ > - struct virtnet_rq_dma *last_dma; > - > struct xsk_buff_pool *xsk_pool; > > /* xdp rxq used by xsk */ > @@ -521,11 +513,14 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, > struct virtnet_rq_stats *stats); > static void virtnet_receive_done(struct virtnet_info *vi, struct receive_queue *rq, > struct sk_buff *skb, u8 flags); > -static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, > +static struct sk_buff *virtnet_skb_append_frag(struct receive_queue *rq, > + struct sk_buff *head_skb, > struct sk_buff *curr_skb, > struct page *page, void *buf, > int len, int truesize); > static void virtnet_xsk_completed(struct send_queue *sq, int num); > +static void free_unused_bufs(struct virtnet_info *vi); > +static void virtnet_del_vqs(struct virtnet_info *vi); > > enum virtnet_xmit_type { > VIRTNET_XMIT_TYPE_SKB, > @@ -709,12 +704,10 @@ static struct page *get_a_page(struct receive_queue *rq, gfp_t gfp_mask) > 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) > + if (!rq->page_pool) > give_pages(rq, buf); > else > - put_page(virt_to_head_page(buf)); > + page_pool_put_page(rq->page_pool, virt_to_head_page(buf), -1, false); > } > > static void enable_rx_mode_work(struct virtnet_info *vi) > @@ -876,10 +869,16 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > skb = virtnet_build_skb(buf, truesize, p - buf, len); > if (unlikely(!skb)) > return NULL; > + /* Big packets mode chains pages via page->private, which is > + * incompatible with the way page_pool uses page->private. > + * Currently, big packets mode doesn't use page pools. > + */ > + if (!rq->page_pool) { > + page = (struct page *)page->private; > + if (page) > + give_pages(rq, page); > + } > > - page = (struct page *)page->private; > - if (page) > - give_pages(rq, page); > goto ok; > } > > @@ -925,133 +924,16 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > hdr = skb_vnet_common_hdr(skb); > memcpy(hdr, hdr_p, hdr_len); > if (page_to_free) > - put_page(page_to_free); > + page_pool_put_page(rq->page_pool, page_to_free, -1, true); > > return skb; > } > > -static void virtnet_rq_unmap(struct receive_queue *rq, void *buf, u32 len) > -{ > - struct virtnet_info *vi = rq->vq->vdev->priv; > - struct page *page = virt_to_head_page(buf); > - struct virtnet_rq_dma *dma; > - void *head; > - int offset; > - > - BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs); > - > - head = page_address(page); > - > - dma = head; > - > - --dma->ref; > - > - if (dma->need_sync && len) { > - offset = buf - (head + sizeof(*dma)); > - > - virtqueue_map_sync_single_range_for_cpu(rq->vq, dma->addr, > - offset, len, > - DMA_FROM_DEVICE); > - } > - > - if (dma->ref) > - return; > - > - virtqueue_unmap_single_attrs(rq->vq, dma->addr, dma->len, > - DMA_FROM_DEVICE, DMA_ATTR_SKIP_CPU_SYNC); > - put_page(page); > -} > - > static void *virtnet_rq_get_buf(struct receive_queue *rq, u32 *len, void **ctx) > { > - struct virtnet_info *vi = rq->vq->vdev->priv; > - void *buf; > - > - BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs); > - > - buf = virtqueue_get_buf_ctx(rq->vq, len, ctx); > - if (buf) > - virtnet_rq_unmap(rq, buf, *len); > - > - return buf; > -} > - > -static void virtnet_rq_init_one_sg(struct receive_queue *rq, void *buf, u32 len) > -{ > - struct virtnet_info *vi = rq->vq->vdev->priv; > - struct virtnet_rq_dma *dma; > - dma_addr_t addr; > - u32 offset; > - void *head; > - > - BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs); > - > - head = page_address(rq->alloc_frag.page); > - > - offset = buf - head; > - > - dma = head; > - > - addr = dma->addr - sizeof(*dma) + offset; > - > - sg_init_table(rq->sg, 1); > - sg_fill_dma(rq->sg, addr, len); > -} > - > -static void *virtnet_rq_alloc(struct receive_queue *rq, u32 size, gfp_t gfp) > -{ > - struct page_frag *alloc_frag = &rq->alloc_frag; > - struct virtnet_info *vi = rq->vq->vdev->priv; > - struct virtnet_rq_dma *dma; > - void *buf, *head; > - dma_addr_t addr; > - > - BUG_ON(vi->big_packets && !vi->mergeable_rx_bufs); > - > - head = page_address(alloc_frag->page); > - > - dma = head; > - > - /* new pages */ > - if (!alloc_frag->offset) { > - if (rq->last_dma) { > - /* Now, the new page is allocated, the last dma > - * will not be used. So the dma can be unmapped > - * if the ref is 0. > - */ > - virtnet_rq_unmap(rq, rq->last_dma, 0); > - rq->last_dma = NULL; > - } > - > - dma->len = alloc_frag->size - sizeof(*dma); > - > - addr = virtqueue_map_single_attrs(rq->vq, dma + 1, > - dma->len, DMA_FROM_DEVICE, 0); > - if (virtqueue_map_mapping_error(rq->vq, addr)) > - return NULL; > - > - dma->addr = addr; > - dma->need_sync = virtqueue_map_need_sync(rq->vq, addr); > - > - /* Add a reference to dma to prevent the entire dma from > - * being released during error handling. This reference > - * will be freed after the pages are no longer used. > - */ > - get_page(alloc_frag->page); > - dma->ref = 1; > - alloc_frag->offset = sizeof(*dma); > - > - rq->last_dma = dma; > - } > - > - ++dma->ref; > - > - buf = head + alloc_frag->offset; > - > - get_page(alloc_frag->page); > - alloc_frag->offset += size; > + BUG_ON(!rq->page_pool); > > - return buf; > + return virtqueue_get_buf_ctx(rq->vq, len, ctx); > } > > static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) > @@ -1067,9 +949,6 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) > return; > } > > - if (!vi->big_packets || vi->mergeable_rx_bufs) > - virtnet_rq_unmap(rq, buf, 0); > - > virtnet_rq_free_buf(vi, rq, buf); > } > > @@ -1335,7 +1214,7 @@ static int xsk_append_merge_buffer(struct virtnet_info *vi, > > truesize = len; > > - curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page, > + curr_skb = virtnet_skb_append_frag(rq, head_skb, curr_skb, page, > buf, len, truesize); > if (!curr_skb) { > put_page(page); > @@ -1771,7 +1650,7 @@ static int virtnet_xdp_xmit(struct net_device *dev, > return ret; > } > > -static void put_xdp_frags(struct xdp_buff *xdp) > +static void put_xdp_frags(struct receive_queue *rq, struct xdp_buff *xdp) > { > struct skb_shared_info *shinfo; > struct page *xdp_page; > @@ -1781,7 +1660,7 @@ static void put_xdp_frags(struct xdp_buff *xdp) > shinfo = xdp_get_shared_info_from_buff(xdp); > for (i = 0; i < shinfo->nr_frags; i++) { > xdp_page = skb_frag_page(&shinfo->frags[i]); > - put_page(xdp_page); > + page_pool_put_page(rq->page_pool, xdp_page, -1, true); > } > } > } > @@ -1873,7 +1752,7 @@ static struct page *xdp_linearize_page(struct net_device *dev, > if (page_off + *len + tailroom > PAGE_SIZE) > return NULL; > > - page = alloc_page(GFP_ATOMIC); > + page = page_pool_alloc_pages(rq->page_pool, GFP_ATOMIC); > if (!page) > return NULL; > > @@ -1896,8 +1775,12 @@ static struct page *xdp_linearize_page(struct net_device *dev, > p = virt_to_head_page(buf); > off = buf - page_address(p); > > + if (rq->use_page_pool_dma) > + page_pool_dma_sync_for_cpu(rq->page_pool, p, > + off, buflen); > + > if (check_mergeable_len(dev, ctx, buflen)) { > - put_page(p); > + page_pool_put_page(rq->page_pool, p, -1, true); > goto err_buf; > } > > @@ -1905,21 +1788,21 @@ static struct page *xdp_linearize_page(struct net_device *dev, > * is sending packet larger than the MTU. > */ > if ((page_off + buflen + tailroom) > PAGE_SIZE) { > - put_page(p); > + page_pool_put_page(rq->page_pool, p, -1, true); > goto err_buf; > } > > memcpy(page_address(page) + page_off, > page_address(p) + off, buflen); > page_off += buflen; > - put_page(p); > + page_pool_put_page(rq->page_pool, p, -1, true); > } > > /* Headroom does not contribute to packet length */ > *len = page_off - XDP_PACKET_HEADROOM; > return page; > err_buf: > - __free_pages(page, 0); > + page_pool_put_page(rq->page_pool, page, -1, true); > return NULL; > } > > @@ -1996,7 +1879,7 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, > goto err_xdp; > > buf = page_address(xdp_page); > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > page = xdp_page; > } > > @@ -2028,13 +1911,15 @@ static struct sk_buff *receive_small_xdp(struct net_device *dev, > if (metasize) > skb_metadata_set(skb, metasize); > > + skb_mark_for_recycle(skb); > + > return skb; > > err_xdp: > u64_stats_inc(&stats->xdp_drops); > err: > u64_stats_inc(&stats->drops); > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > xdp_xmit: > return NULL; > } > @@ -2056,6 +1941,13 @@ static struct sk_buff *receive_small(struct net_device *dev, > */ > buf -= VIRTNET_RX_PAD + xdp_headroom; > > + if (rq->use_page_pool_dma) { > + int offset = buf - page_address(page) + > + VIRTNET_RX_PAD + xdp_headroom; > + > + page_pool_dma_sync_for_cpu(rq->page_pool, page, offset, len); > + } > + > len -= vi->hdr_len; > u64_stats_add(&stats->bytes, len); > > @@ -2082,12 +1974,14 @@ static struct sk_buff *receive_small(struct net_device *dev, > } > > skb = receive_small_build_skb(vi, xdp_headroom, buf, len); > - if (likely(skb)) > + if (likely(skb)) { > + skb_mark_for_recycle(skb); > return skb; > + } > > err: > u64_stats_inc(&stats->drops); > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > return NULL; > } > > @@ -2142,7 +2036,7 @@ static void mergeable_buf_free(struct receive_queue *rq, int num_buf, > } > u64_stats_add(&stats->bytes, len); > page = virt_to_head_page(buf); > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > } > } > > @@ -2252,8 +2146,12 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, > page = virt_to_head_page(buf); > offset = buf - page_address(page); > > + if (rq->use_page_pool_dma) > + page_pool_dma_sync_for_cpu(rq->page_pool, page, > + offset, len); > + > if (check_mergeable_len(dev, ctx, len)) { > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > goto err; > } > > @@ -2272,7 +2170,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev, > return 0; > > err: > - put_xdp_frags(xdp); > + put_xdp_frags(rq, xdp); > return -EINVAL; > } > > @@ -2337,7 +2235,7 @@ static void *mergeable_xdp_get_buf(struct virtnet_info *vi, > if (*len + xdp_room > PAGE_SIZE) > return NULL; > > - xdp_page = alloc_page(GFP_ATOMIC); > + xdp_page = page_pool_alloc_pages(rq->page_pool, GFP_ATOMIC); > if (!xdp_page) > return NULL; > > @@ -2347,7 +2245,7 @@ static void *mergeable_xdp_get_buf(struct virtnet_info *vi, > > *frame_sz = PAGE_SIZE; > > - put_page(*page); > + page_pool_put_page(rq->page_pool, *page, -1, true); > > *page = xdp_page; > > @@ -2393,6 +2291,8 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); > if (unlikely(!head_skb)) > break; > + > + skb_mark_for_recycle(head_skb); > return head_skb; > > case XDP_TX: > @@ -2403,10 +2303,10 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > break; > } > > - put_xdp_frags(&xdp); > + put_xdp_frags(rq, &xdp); > > err_xdp: > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > mergeable_buf_free(rq, num_buf, dev, stats); > > u64_stats_inc(&stats->xdp_drops); > @@ -2414,7 +2314,8 @@ static struct sk_buff *receive_mergeable_xdp(struct net_device *dev, > return NULL; > } > > -static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, > +static struct sk_buff *virtnet_skb_append_frag(struct receive_queue *rq, > + struct sk_buff *head_skb, > struct sk_buff *curr_skb, > struct page *page, void *buf, > int len, int truesize) > @@ -2429,6 +2330,9 @@ static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, > if (unlikely(!nskb)) > return NULL; > > + if (head_skb->pp_recycle) > + skb_mark_for_recycle(nskb); > + > if (curr_skb == head_skb) > skb_shinfo(curr_skb)->frag_list = nskb; > else > @@ -2446,7 +2350,10 @@ static struct sk_buff *virtnet_skb_append_frag(struct sk_buff *head_skb, > > offset = buf - page_address(page); > if (skb_can_coalesce(curr_skb, num_skb_frags, page, offset)) { > - put_page(page); > + if (head_skb->pp_recycle) > + page_pool_put_page(rq->page_pool, page, -1, true); > + else > + put_page(page); > skb_coalesce_rx_frag(curr_skb, num_skb_frags - 1, > len, truesize); > } else { > @@ -2475,6 +2382,10 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > unsigned int headroom = mergeable_ctx_to_headroom(ctx); > > head_skb = NULL; > + > + if (rq->use_page_pool_dma) > + page_pool_dma_sync_for_cpu(rq->page_pool, page, offset, len); > + > u64_stats_add(&stats->bytes, len - vi->hdr_len); > > if (check_mergeable_len(dev, ctx, len)) > @@ -2499,6 +2410,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > > if (unlikely(!curr_skb)) > goto err_skb; > + > + skb_mark_for_recycle(head_skb); > while (--num_buf) { > buf = virtnet_rq_get_buf(rq, &len, &ctx); > if (unlikely(!buf)) { > @@ -2513,11 +2426,17 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > u64_stats_add(&stats->bytes, len); > page = virt_to_head_page(buf); > > + if (rq->use_page_pool_dma) { > + offset = buf - page_address(page); > + page_pool_dma_sync_for_cpu(rq->page_pool, page, > + offset, len); > + } > + > if (check_mergeable_len(dev, ctx, len)) > goto err_skb; > > truesize = mergeable_ctx_to_truesize(ctx); > - curr_skb = virtnet_skb_append_frag(head_skb, curr_skb, page, > + curr_skb = virtnet_skb_append_frag(rq, head_skb, curr_skb, page, > buf, len, truesize); > if (!curr_skb) > goto err_skb; > @@ -2527,7 +2446,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > return head_skb; > > err_skb: > - put_page(page); > + page_pool_put_page(rq->page_pool, page, -1, true); > mergeable_buf_free(rq, num_buf, dev, stats); > > err_buf: > @@ -2658,6 +2577,24 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, > virtnet_receive_done(vi, rq, skb, flags); > } > > +static int virtnet_rq_submit(struct receive_queue *rq, char *buf, > + int len, void *ctx, gfp_t gfp) > +{ > + if (rq->use_page_pool_dma) { > + struct page *page = virt_to_head_page(buf); > + dma_addr_t addr = page_pool_get_dma_addr(page) + > + (buf - (char *)page_address(page)); > + > + sg_init_table(rq->sg, 1); > + sg_fill_dma(rq->sg, addr, len); > + return virtqueue_add_inbuf_premapped(rq->vq, rq->sg, 1, > + buf, ctx, gfp); > + } > + > + sg_init_one(rq->sg, buf, len); > + return virtqueue_add_inbuf_ctx(rq->vq, rq->sg, 1, buf, ctx, gfp); > +} > + > /* Unlike mergeable buffers, all buffers are allocated to the > * same size, except for the headroom. For this reason we do > * not need to use mergeable_len_to_ctx here - it is enough > @@ -2666,32 +2603,27 @@ static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, > static int add_recvbuf_small(struct virtnet_info *vi, struct receive_queue *rq, > gfp_t gfp) > { > - char *buf; > unsigned int xdp_headroom = virtnet_get_headroom(vi); > void *ctx = (void *)(unsigned long)xdp_headroom; > - int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom; > + unsigned int len = vi->hdr_len + VIRTNET_RX_PAD + GOOD_PACKET_LEN + xdp_headroom; > + unsigned int alloc_len; > + char *buf; > int err; > > len = SKB_DATA_ALIGN(len) + > SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); > > - if (unlikely(!skb_page_frag_refill(len, &rq->alloc_frag, gfp))) > - return -ENOMEM; > - > - buf = virtnet_rq_alloc(rq, len, gfp); > + alloc_len = len; > + buf = page_pool_alloc_va(rq->page_pool, &alloc_len, gfp); > if (unlikely(!buf)) > return -ENOMEM; As noted by Micheal in the previous revision the above will skb->truesize under accounting. That is not safe and at least need a solid explaination, which is still missing. /P