From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D2F79C54FCB for ; Wed, 22 Apr 2020 16:08:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AFAD320774 for ; Wed, 22 Apr 2020 16:08:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="KHLR6VAH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726853AbgDVQIk (ORCPT ); Wed, 22 Apr 2020 12:08:40 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:38436 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726006AbgDVQIk (ORCPT ); Wed, 22 Apr 2020 12:08:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587571718; 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=E+Fa11a8aGuOJg54L4Y3OCGgdDIxawWq4V0asjQCeJI=; b=KHLR6VAH5tdWAlC7pgZWnDdacTs2AqEhqPavcUjLwa1aD/P28X/bSR+lwhkUaz95uuXUtD 53eunjFSm8iqodhxfi/YeL65Qr/5vmw0CVjuDdmAgcfrEunRw9q0SpQQcIw7PwKYaAXBQc PjFBZkE7XnXOD7KLb4oHaJ6iTFpujVY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-198-kgq7xCUVN0is1w5T8y318Q-1; Wed, 22 Apr 2020 12:08:37 -0400 X-MC-Unique: kgq7xCUVN0is1w5T8y318Q-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 44EA1800FC7; Wed, 22 Apr 2020 16:08:34 +0000 (UTC) Received: from firesoul.localdomain (unknown [10.40.208.3]) by smtp.corp.redhat.com (Postfix) with ESMTP id E35DD1916B; Wed, 22 Apr 2020 16:08:22 +0000 (UTC) Received: from [192.168.42.3] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 1255B30000272; Wed, 22 Apr 2020 18:08:22 +0200 (CEST) Subject: [PATCH net-next 12/33] hv_netvsc: add XDP frame size to driver From: Jesper Dangaard Brouer To: sameehj@amazon.com Cc: Wei Liu , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, zorik@amazon.com, akiyano@amazon.com, gtzalik@amazon.com, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Daniel Borkmann , Alexei Starovoitov , John Fastabend , Alexander Duyck , Jeff Kirsher , David Ahern , Willem de Bruijn , Ilias Apalodimas , Lorenzo Bianconi , Saeed Mahameed , steffen.klassert@secunet.com Date: Wed, 22 Apr 2020 18:08:22 +0200 Message-ID: <158757170200.1370371.9930519336386674467.stgit@firesoul> In-Reply-To: <158757160439.1370371.13213378122947426220.stgit@firesoul> References: <158757160439.1370371.13213378122947426220.stgit@firesoul> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The hyperv NIC drivers XDP implementation is rather disappointing as it will be a slowdown to enable XDP on this driver, given it will allocate a new page for each packet and copy over the payload, before invoking the XDP BPF-prog. The positive thing it that its easy to determine the xdp.frame_sz. The XDP implementation for hv_netvsc transparently passes xdp_prog to the associated VF NIC. Many of the Azure VMs are using SRIOV, so majority of the data are actually processed directly on the VF driver's XDP path. So the overhead of the synthetic data path (hv_netvsc) is minimal. Then XDP is enabled on this driver, XDP_PASS and XDP_TX will create the SKB via build_skb (based on the newly allocated page). Now using XDP frame_sz this will provide more skb_tailroom, which netstack can use for SKB coalescing (e.g tcp_try_coalesce -> skb_try_coalesce). Cc: Wei Liu Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Signed-off-by: Jesper Dangaard Brouer --- drivers/net/hyperv/netvsc_bpf.c | 1 + drivers/net/hyperv/netvsc_drv.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/hyperv/netvsc_bpf.c b/drivers/net/hyperv/netvsc_bpf.c index b86611041db6..1e0c024b0a93 100644 --- a/drivers/net/hyperv/netvsc_bpf.c +++ b/drivers/net/hyperv/netvsc_bpf.c @@ -49,6 +49,7 @@ u32 netvsc_run_xdp(struct net_device *ndev, struct netvsc_channel *nvchan, xdp_set_data_meta_invalid(xdp); xdp->data_end = xdp->data + len; xdp->rxq = &nvchan->xdp_rxq; + xdp->frame_sz = PAGE_SIZE; xdp->handle = 0; memcpy(xdp->data, data, len); diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index d8e86bdbfba1..651344fea0a5 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -794,7 +794,7 @@ static struct sk_buff *netvsc_alloc_recv_skb(struct net_device *net, if (xbuf) { unsigned int hdroom = xdp->data - xdp->data_hard_start; unsigned int xlen = xdp->data_end - xdp->data; - unsigned int frag_size = netvsc_xdp_fraglen(hdroom + xlen); + unsigned int frag_size = xdp->frame_sz; skb = build_skb(xbuf, frag_size);