From patchwork Mon Dec 28 16:22:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Willem de Bruijn X-Patchwork-Id: 354195 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 98424C4332B for ; Mon, 28 Dec 2020 16:23:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CD5B208B6 for ; Mon, 28 Dec 2020 16:23:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2441027AbgL1QXV (ORCPT ); Mon, 28 Dec 2020 11:23:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2441018AbgL1QXT (ORCPT ); Mon, 28 Dec 2020 11:23:19 -0500 Received: from mail-qv1-xf2f.google.com (mail-qv1-xf2f.google.com [IPv6:2607:f8b0:4864:20::f2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00E4EC061793 for ; Mon, 28 Dec 2020 08:22:39 -0800 (PST) Received: by mail-qv1-xf2f.google.com with SMTP id bd6so5130330qvb.9 for ; Mon, 28 Dec 2020 08:22:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=E+P5deBgMfEMNVf0vB1e6Pyaa3lRUXorz/FFexYbRww=; b=p+sxNA67eY0qGzrr2ZW6sQAHd9YD0jBivT9ziHSrGJMTY4UrjK4ppFohD1CVbPCzxZ WI/Ex9/QF5cywFlBBJ5ZPgKp58cgSI9ffH5PbjMk7oHXQMoN2sJf5IB5eAjUSsdAwDDo u3KQTI2/2KRBWvhoP5wVuJk9Np8K0XSbe1H2kBEKYScpCUsfuJgusA+9dX9oOuYNbaIj Nuxnf9A/oCB3j61hFK7ONtm78MzDSFseEGs2GkUOuRiHAE8whBocmAoezYr7C/ln+ObI d3fySF12MrE0fO3LrJfOY8sxx2RM+u18qN/5D1mMcWdrgxccRHvpFFlp5VU3EKApVs4w CBdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=E+P5deBgMfEMNVf0vB1e6Pyaa3lRUXorz/FFexYbRww=; b=O3NcwfJcmLc8rmWwLNv80u4YtGU8qck0DPeP6jSKwWT4JA8Ytk3IA2o1DasaXF+MZS 2ZNBA4Hl213VRB6qThKZu7AWPk4N2M9ek60QMgEp8l4BHv/rqZcqwHObbAElys+2Ld1D 6I4UIDijZEa7yA4MXfBW8xnSS7fXPas+RZy8woYmr2Boj1yS3ykjTnebvCkd23+GqOp+ dPIiY/QEBsBxEMzoRO8NbqWtyahu1zNdGWPZrRXBI8QkLeZTqSzQ28Oje7MufKxJ5Afa HQtRr/pzaMIaay1F7ryCxro3865EyizoKVDc7Wr+zVInJJpoMjtAJ5SENpYJ29/AYd7R WzRg== X-Gm-Message-State: AOAM532kZQUtNGNPfxx+S/WHQoB5D75Tm6u4DOAPUBBJTBZpatBoGQ09 QgblWXHDDvgv/FJ6OXpuSo0= X-Google-Smtp-Source: ABdhPJyzCEi17L8Bqx+W7irotxFVqlBZ0ufvsoQmL1pqrzYK2d80AdgiRcapqv28GPFkJFMeEo0uMA== X-Received: by 2002:a0c:fe90:: with SMTP id d16mr48310260qvs.13.1609172558271; Mon, 28 Dec 2020 08:22:38 -0800 (PST) Received: from willemb.nyc.corp.google.com ([2620:0:1003:312:f693:9fff:fef4:3e8a]) by smtp.gmail.com with ESMTPSA id u65sm24005556qkb.58.2020.12.28.08.22.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Dec 2020 08:22:37 -0800 (PST) From: Willem de Bruijn To: virtualization@lists.linux-foundation.org Cc: netdev@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, Willem de Bruijn Subject: [PATCH rfc 1/3] virtio-net: support transmit hash report Date: Mon, 28 Dec 2020 11:22:31 -0500 Message-Id: <20201228162233.2032571-2-willemdebruijn.kernel@gmail.com> X-Mailer: git-send-email 2.29.2.729.g45daf8777d-goog In-Reply-To: <20201228162233.2032571-1-willemdebruijn.kernel@gmail.com> References: <20201228162233.2032571-1-willemdebruijn.kernel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Willem de Bruijn Virtio-net supports sharing the flow hash from host to guest on rx. Do the same on transmit, to allow the host to infer connection state for more robust routing and telemetry. Linux derives ipv6 flowlabel and ECMP multipath from sk->sk_txhash, and updates these fields on error with sk_rethink_txhash. This feature allows the host to make similar decisions. Besides the raw hash, optionally also convey connection state for this hash. Specifically, the hash rotates on transmit timeout. To avoid having to keep a stateful table in the host to detect flow changes, explicitly notify when a hash changed due to timeout. Signed-off-by: Willem de Bruijn --- drivers/net/virtio_net.c | 24 +++++++++++++++++++++--- include/uapi/linux/virtio_net.h | 10 +++++++++- 2 files changed, 30 insertions(+), 4 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 21b71148c532..b917b7333928 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -201,6 +201,9 @@ struct virtnet_info { /* Host will merge rx buffers for big packets (shake it! shake it!) */ bool mergeable_rx_bufs; + /* Guest will pass tx path info to the host */ + bool has_tx_hash; + /* Has control virtqueue */ bool has_cvq; @@ -394,9 +397,9 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, hdr_len = vi->hdr_len; if (vi->mergeable_rx_bufs) - hdr_padded_len = sizeof(*hdr); + hdr_padded_len = max_t(unsigned int, hdr_len, sizeof(*hdr)); else - hdr_padded_len = sizeof(struct padded_vnet_hdr); + hdr_padded_len = ALIGN(hdr_len, 16); /* hdr_valid means no XDP, so we can copy the vnet header */ if (hdr_valid) @@ -1534,6 +1537,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) struct virtio_net_hdr_mrg_rxbuf *hdr; const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; struct virtnet_info *vi = sq->vq->vdev->priv; + struct virtio_net_hdr_v1_hash *ht; int num_sg; unsigned hdr_len = vi->hdr_len; bool can_push; @@ -1558,6 +1562,14 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) if (vi->mergeable_rx_bufs) hdr->num_buffers = 0; + ht = (void *)hdr; + if (vi->has_tx_hash) { + ht->hash_value = cpu_to_virtio32(vi->vdev, skb->hash); + ht->hash_report = skb->l4_hash ? VIRTIO_NET_HASH_REPORT_L4 : + VIRTIO_NET_HASH_REPORT_OTHER; + ht->hash_state = VIRTIO_NET_HASH_STATE_DEFAULT; + } + sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2)); if (can_push) { __skb_push(skb, hdr_len); @@ -3054,6 +3066,11 @@ static int virtnet_probe(struct virtio_device *vdev) else vi->hdr_len = sizeof(struct virtio_net_hdr); + if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_TX_HASH)) { + vi->has_tx_hash = true; + vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash); + } + if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) || virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) vi->any_header_sg = true; @@ -3243,7 +3260,8 @@ static struct virtio_device_id id_table[] = { VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, \ VIRTIO_NET_F_CTRL_MAC_ADDR, \ VIRTIO_NET_F_MTU, VIRTIO_NET_F_CTRL_GUEST_OFFLOADS, \ - VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY + VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \ + VIRTIO_NET_F_TX_HASH static unsigned int features[] = { VIRTNET_FEATURES, diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index 3f55a4215f11..f6881b5b77ee 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -57,6 +57,7 @@ * Steering */ #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ +#define VIRTIO_NET_F_TX_HASH 56 /* Guest sends hash report */ #define VIRTIO_NET_F_HASH_REPORT 57 /* Supports hash report */ #define VIRTIO_NET_F_RSS 60 /* Supports RSS RX steering */ #define VIRTIO_NET_F_RSC_EXT 61 /* extended coalescing info */ @@ -170,8 +171,15 @@ struct virtio_net_hdr_v1_hash { #define VIRTIO_NET_HASH_REPORT_IPv6_EX 7 #define VIRTIO_NET_HASH_REPORT_TCPv6_EX 8 #define VIRTIO_NET_HASH_REPORT_UDPv6_EX 9 +#define VIRTIO_NET_HASH_REPORT_L4 10 +#define VIRTIO_NET_HASH_REPORT_OTHER 11 __le16 hash_report; - __le16 padding; + union { + __le16 padding; +#define VIRTIO_NET_HASH_STATE_DEFAULT 0 +#define VIRTIO_NET_HASH_STATE_TIMEOUT_BIT 0x1 + __le16 hash_state; + }; }; #ifndef VIRTIO_NET_NO_LEGACY