From patchwork Mon Feb 8 18:55:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Willem de Bruijn X-Patchwork-Id: 378944 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=-15.8 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 84B0CC433E0 for ; Mon, 8 Feb 2021 19:00:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20D2364E73 for ; Mon, 8 Feb 2021 19:00:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234553AbhBHS74 (ORCPT ); Mon, 8 Feb 2021 13:59:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43998 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235863AbhBHS5V (ORCPT ); Mon, 8 Feb 2021 13:57:21 -0500 Received: from mail-qv1-xf2e.google.com (mail-qv1-xf2e.google.com [IPv6:2607:f8b0:4864:20::f2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E5EC7C061797 for ; Mon, 8 Feb 2021 10:56:05 -0800 (PST) Received: by mail-qv1-xf2e.google.com with SMTP id v19so2690951qvl.7 for ; Mon, 08 Feb 2021 10:56:05 -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=SlFTIukFGMkw2OKGh13o3RxnKgGPrgHC1zxY8/NglTM=; b=SmManNau/yVkSieMx4AJ2MuyWqQ9HhPoPAh6toxhVSZddXA20Rkt+6GqluzJFpaRt/ qN43Ekq0uJpn40vzcaqAqWUW/xE0WYr96BupaTOGHdeLo1xbJFsZARcQS5+lWga80oww zJig+1oJKw7O705kvDlb1HMBu0Fad9q1wlvFzUSExZEi6c22me71rRjwC2K7jmAaQi4I ZIIaE154GVHCR3WQrZfdhr1YZTY7NfKDWgk2C9gUVY2+wiebzcv1TV3jHMx6lLE5CuLp rLHt+2LrJnbzhxDu6of2n4Edl0iNMMne3TUIH9hpciMYtbtpX5bqSSHwXNjh+jrnexGu bEgA== 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=SlFTIukFGMkw2OKGh13o3RxnKgGPrgHC1zxY8/NglTM=; b=YOo7tEekCgmX/nByeBa2vmNXR11ySyzpx4H1OBpc8XCLQJLwbnhTdP3NxWtqpjkHFm XdK/ku5VIFTAUcaNWrWvZ8S/kuuITxRmG9iszmO0pnzjKiBSLXDyZ1WCW2m2Oc0fVmtq UrgTJlm+6U+Wp8hib63907N1fwHRRRZdnhfCXfa7BYMyocz1ga42fUhE076j/9hJknMv oAycg6nTe5Ssjq8s0mIm80qRG4z10o9gv8bu2qZYl3F8vRfrWeJVWrrgJDWVhBEc/ivv 0NrDB2iokEJVEEWzKBdbXlsPMhWTKjszBIbOgVsZ0/ePtvBw6HpCsJEhNwfUHr50Uyhz 2dxQ== X-Gm-Message-State: AOAM532/EKFxpUWYdNzAXPcKNl9nf2KiXPCh6IgX21OeTQovJinWLM5d +H4kiVNKZeazHHXc7iJKs8RvGGCduuk= X-Google-Smtp-Source: ABdhPJzPoHHvBqxCa8V0IRqT8YWCiCMF2H/S/6nVea2y4QUfXDo2I3x7BHG2o/EHP+OeOaB1RbXzzw== X-Received: by 2002:a0c:dd8b:: with SMTP id v11mr17411146qvk.31.1612810565070; Mon, 08 Feb 2021 10:56:05 -0800 (PST) Received: from willemb.nyc.corp.google.com ([2620:0:1003:312:f109:45d3:805f:3b83]) by smtp.gmail.com with ESMTPSA id q25sm17370744qkq.32.2021.02.08.10.56.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 08 Feb 2021 10:56:04 -0800 (PST) From: Willem de Bruijn To: virtualization@lists.linux-foundation.org Cc: netdev@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, richardcochran@gmail.com, Willem de Bruijn Subject: [PATCH RFC v2 3/4] virtio-net: support transmit timestamp Date: Mon, 8 Feb 2021 13:55:57 -0500 Message-Id: <20210208185558.995292-4-willemdebruijn.kernel@gmail.com> X-Mailer: git-send-email 2.30.0.478.g8a0d178c01-goog In-Reply-To: <20210208185558.995292-1-willemdebruijn.kernel@gmail.com> References: <20210208185558.995292-1-willemdebruijn.kernel@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Willem de Bruijn Add optional PTP hardware tx timestamp offload for virtio-net. Accurate RTT measurement requires timestamps close to the wire. Introduce virtio feature VIRTIO_NET_F_TX_TSTAMP, the transmit equivalent to VIRTIO_NET_F_RX_TSTAMP. The driver sets VIRTIO_NET_HDR_F_TSTAMP to request a timestamp returned on completion. If the feature is negotiated, the device either places the timestamp or clears the feature bit. The timestamp straddles (virtual) hardware domains. Like PTP, use international atomic time (CLOCK_TAI) as global clock base. The driver must sync with the device, e.g., through kvm-clock. Modify can_push to ensure that on tx completion the header, and thus timestamp, is in a predicatable location at skb_vnet_hdr. RFC: this implementation relies on the device writing to the buffer. That breaks DMA_TO_DEVICE semantics. For now, disable when DMA is on. The virtio changes should be a separate patch at the least. Tested: modified txtimestamp.c to with h/w timestamping: - sock_opt = SOF_TIMESTAMPING_SOFTWARE | + sock_opt = SOF_TIMESTAMPING_RAW_HARDWARE | + do_test(family, SOF_TIMESTAMPING_TX_HARDWARE); Signed-off-by: Willem de Bruijn --- drivers/net/virtio_net.c | 61 ++++++++++++++++++++++++++++----- drivers/virtio/virtio_ring.c | 3 +- include/linux/virtio.h | 1 + include/uapi/linux/virtio_net.h | 1 + 4 files changed, 56 insertions(+), 10 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index ac44c5efa0bc..fc8ecd3a333a 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -210,6 +210,12 @@ struct virtnet_info { /* Device will pass rx timestamp. Requires has_rx_tstamp */ bool enable_rx_tstamp; + /* Device can pass CLOCK_TAI transmit time to the driver */ + bool has_tx_tstamp; + + /* Device will pass tx timestamp. Requires has_tx_tstamp */ + bool enable_tx_tstamp; + /* Has control virtqueue */ bool has_cvq; @@ -1401,6 +1407,20 @@ static int virtnet_receive(struct receive_queue *rq, int budget, return stats.packets; } +static void virtnet_record_tx_tstamp(const struct send_queue *sq, + struct sk_buff *skb) +{ + const struct virtio_net_hdr_hash_ts *h = skb_vnet_hdr_ht(skb); + const struct virtnet_info *vi = sq->vq->vdev->priv; + struct skb_shared_hwtstamps ts; + + if (h->hdr.flags & VIRTIO_NET_HDR_F_TSTAMP && + vi->enable_tx_tstamp) { + ts.hwtstamp = ns_to_ktime(le64_to_cpu(h->tstamp)); + skb_tstamp_tx(skb, &ts); + } +} + static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi) { unsigned int len; @@ -1412,6 +1432,7 @@ static void free_old_xmit_skbs(struct send_queue *sq, bool in_napi) if (likely(!is_xdp_frame(ptr))) { struct sk_buff *skb = ptr; + virtnet_record_tx_tstamp(sq, skb); pr_debug("Sent skb %p\n", skb); bytes += skb->len; @@ -1558,7 +1579,7 @@ 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; + struct virtio_net_hdr_hash_ts *ht; int num_sg; unsigned hdr_len = vi->hdr_len; bool can_push; @@ -1567,7 +1588,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) can_push = vi->any_header_sg && !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) && - !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len; + !skb_header_cloned(skb) && skb_headroom(skb) >= hdr_len && + !vi->enable_tx_tstamp; /* Even if we can, don't push here yet as this would skew * csum_start offset below. */ if (can_push) @@ -1588,10 +1610,12 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) u16 report = skb->l4_hash ? VIRTIO_NET_HASH_REPORT_L4 : VIRTIO_NET_HASH_REPORT_OTHER; - ht->hash_value = cpu_to_le32(skb->hash); - ht->hash_report = cpu_to_le16(report); - ht->hash_state = cpu_to_le16(VIRTIO_NET_HASH_STATE_DEFAULT); + ht->hash.value = cpu_to_le32(skb->hash); + ht->hash.report = cpu_to_le16(report); + ht->hash.flow_state = cpu_to_le16(VIRTIO_NET_HASH_STATE_DEFAULT); } + if (vi->enable_tx_tstamp && skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) + ht->hdr.flags |= VIRTIO_NET_HDR_F_TSTAMP; sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2)); if (can_push) { @@ -2307,7 +2331,13 @@ static int virtnet_get_ts_info(struct net_device *dev, info->rx_filters = HWTSTAMP_FILTER_NONE; } - info->tx_types = HWTSTAMP_TX_OFF; + if (vi->has_tx_tstamp) { + info->so_timestamping |= SOF_TIMESTAMPING_TX_HARDWARE | + SOF_TIMESTAMPING_RAW_HARDWARE; + info->tx_types = HWTSTAMP_TX_ON; + } else { + info->tx_types = HWTSTAMP_TX_OFF; + } return 0; } @@ -2616,7 +2646,8 @@ static int virtnet_ioctl_set_hwtstamp(struct net_device *dev, struct ifreq *ifr) return -EFAULT; if (tsconf.flags) return -EINVAL; - if (tsconf.tx_type != HWTSTAMP_TX_OFF) + if (tsconf.tx_type != HWTSTAMP_TX_OFF && + tsconf.tx_type != HWTSTAMP_TX_ON) return -ERANGE; if (tsconf.rx_filter != HWTSTAMP_FILTER_NONE && tsconf.rx_filter != HWTSTAMP_FILTER_ALL) @@ -2627,6 +2658,11 @@ static int virtnet_ioctl_set_hwtstamp(struct net_device *dev, struct ifreq *ifr) else vi->enable_rx_tstamp = tsconf.rx_filter == HWTSTAMP_FILTER_ALL; + if (!vi->has_tx_tstamp) + tsconf.tx_type = HWTSTAMP_TX_OFF; + else + vi->enable_tx_tstamp = tsconf.tx_type == HWTSTAMP_TX_ON; + if (copy_to_user(ifr->ifr_data, &tsconf, sizeof(tsconf))) return -EFAULT; @@ -2641,7 +2677,8 @@ static int virtnet_ioctl_get_hwtstamp(struct net_device *dev, struct ifreq *ifr) tsconf.flags = 0; tsconf.rx_filter = vi->enable_rx_tstamp ? HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE; - tsconf.tx_type = HWTSTAMP_TX_OFF; + tsconf.tx_type = vi->enable_tx_tstamp ? HWTSTAMP_TX_ON : + HWTSTAMP_TX_OFF; if (copy_to_user(ifr->ifr_data, &tsconf, sizeof(tsconf))) return -EFAULT; @@ -3178,6 +3215,12 @@ static int virtnet_probe(struct virtio_device *vdev) vi->hdr_len = sizeof(struct virtio_net_hdr_hash_ts); } + if (virtio_has_feature(vdev, VIRTIO_NET_F_TX_TSTAMP) && + !vring_use_dma_api(vdev)) { + vi->has_tx_tstamp = true; + vi->hdr_len = sizeof(struct virtio_net_hdr_hash_ts); + } + if (virtio_has_feature(vdev, VIRTIO_F_ANY_LAYOUT) || virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) vi->any_header_sg = true; @@ -3369,7 +3412,7 @@ static struct virtio_device_id id_table[] = { 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_TX_HASH, VIRTIO_NET_F_RX_TSTAMP + VIRTIO_NET_F_TX_HASH, VIRTIO_NET_F_RX_TSTAMP, VIRTIO_NET_F_TX_TSTAMP static unsigned int features[] = { VIRTNET_FEATURES, diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 71e16b53e9c1..cf5d5d1f9b14 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -238,7 +238,7 @@ static inline bool virtqueue_use_indirect(struct virtqueue *_vq, * unconditionally on data path. */ -static bool vring_use_dma_api(struct virtio_device *vdev) +bool vring_use_dma_api(struct virtio_device *vdev) { if (!virtio_has_dma_quirk(vdev)) return true; @@ -257,6 +257,7 @@ static bool vring_use_dma_api(struct virtio_device *vdev) return false; } +EXPORT_SYMBOL_GPL(vring_use_dma_api); size_t virtio_max_dma_size(struct virtio_device *vdev) { diff --git a/include/linux/virtio.h b/include/linux/virtio.h index 55ea329fe72a..5289e2812e95 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -140,6 +140,7 @@ int virtio_device_freeze(struct virtio_device *dev); int virtio_device_restore(struct virtio_device *dev); #endif +bool vring_use_dma_api(struct virtio_device *vdev); size_t virtio_max_dma_size(struct virtio_device *vdev); #define virtio_device_for_each_vq(vdev, vq) \ diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h index a5c84410cf92..b5d6f0c6cead 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_TSTAMP 54 /* Device sends TAI transmit time */ #define VIRTIO_NET_F_RX_TSTAMP 55 /* Device sends TAI receive time */ #define VIRTIO_NET_F_TX_HASH 56 /* Driver sends hash report */ #define VIRTIO_NET_F_HASH_REPORT 57 /* Supports hash report */