From nobody Sat Dec 27 18:57:15 2025 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (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 35EC931747 for ; Mon, 18 Dec 2023 11:38:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=ratatoskr.trumtrar.info) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1rFBwY-0000Vp-Or; Mon, 18 Dec 2023 12:37:54 +0100 From: Steffen Trumtrar Date: Mon, 18 Dec 2023 12:37:09 +0100 Subject: [PATCH RFC 2/4] virtio-net: support receive timestamp Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20231218-v6-7-topic-virtio-net-ptp-v1-2-cac92b2d8532@pengutronix.de> References: <20231218-v6-7-topic-virtio-net-ptp-v1-0-cac92b2d8532@pengutronix.de> In-Reply-To: <20231218-v6-7-topic-virtio-net-ptp-v1-0-cac92b2d8532@pengutronix.de> To: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Richard Cochran Cc: virtualization@lists.linux.dev, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Willem de Bruijn X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=9439; i=s.trumtrar@pengutronix.de; h=from:subject:message-id; bh=/amFfGGN0ySjYA0bFqG8F1jrShubaLWAjnl+dO9RuW8=; b=owGbwMvMwCUmvd38QH3grB+Mp9WSGFIb9BmL9dvdJb3/hR9bZJG+i9u3yf+Yl+FMF8bPu1McvI/c OqzQUcrCIMbFICumyBK59pDGZuHPOl+On2eAmcPKBDKEgYtTACbyi4+RYcmhW7p/lLT4blf8PtdU6L LloFxpxFvLKUU7jiS81ffTMWL4724eLRoa9Sz+duaE1EtnGH9XlJmozNmxgFvzyM7Fu7aacAIA X-Developer-Key: i=s.trumtrar@pengutronix.de; a=openpgp; fpr=59ADC228B313F32CF4C7CF001BB737C07F519AF8 X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: s.trumtrar@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org From: Willem de Bruijn Add optional PTP hardware rx timestamp offload for virtio-net. Accurate RTT measurement requires timestamps close to the wire. Introduce virtio feature VIRTIO_NET_F_RX_TSTAMP. If negotiated, the virtio-net header is expanded with room for a timestamp. A device may pass receive timestamps for all or some packets. Flag VIRTIO_NET_HDR_F_TSTAMP signals whether a timestamp is recorded. A driver that supports hardware timestamping must also support ioctl SIOCSHWTSTAMP. Implement that, as well as information getters ioctl SIOCGHWTSTAMP and ethtool get_ts_info (`ethtool -T $DEV`). 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. Tested: guest: ./timestamping eth0 \ SOF_TIMESTAMPING_RAW_HARDWARE \ SOF_TIMESTAMPING_RX_HARDWARE host: nc -4 -u 192.168.1.1 319 Changes RFC -> RFCv2 - rename virtio_net_hdr_v12 to virtio_net_hdr_hash_ts - add ethtool .get_ts_info to query capabilities - add ioctl SIOC[GS]HWTSTAMP to configure feature - add vi->enable_rx_tstamp to store configuration - convert virtioXX_to_cpu to leXX_to_cpu - convert reserved to __u32 Signed-off-by: Willem de Bruijn Co-developed-by: Steffen Trumtrar Signed-off-by: Steffen Trumtrar -- Changes to original RFCv2 - move virtio_net_hdr_v1 into hash-struct --- drivers/net/virtio_net.c | 113 ++++++++++++++++++++++++++++++++++++= +++- include/uapi/linux/virtio_net.h | 13 +++++ 2 files changed, 124 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 8c9de31af8942..9bb6cdaf49cc9 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -274,6 +274,12 @@ struct virtnet_info { /* Driver will pass tx path info to the device */ bool has_tx_hash; =20 + /* Device can pass CLOCK_TAI receive time to the driver */ + bool has_rx_tstamp; + + /* Device will pass rx timestamp. Requires has_rx_tstamp */ + bool enable_rx_tstamp; + /* Has control virtqueue */ bool has_cvq; =20 @@ -384,6 +390,13 @@ skb_vnet_common_hdr(struct sk_buff *skb) return (struct virtio_net_common_hdr *)skb->cb; } =20 +static inline struct virtio_net_hdr_hash_ts *skb_vnet_hdr_ht(struct sk_buf= f *skb) +{ + BUILD_BUG_ON(sizeof(struct virtio_net_hdr_hash_ts) > sizeof(skb->cb)); + + return (void *)skb->cb; +} + /* * private is used to chain pages for big packets, put the whole * most recent used list in the beginning for reuse @@ -1755,6 +1768,19 @@ static void virtio_skb_set_hash(const struct virtio_= net_hdr_v1_hash *hdr_hash, skb_set_hash(skb, __le32_to_cpu(hdr_hash->hash_value), rss_hash_type); } =20 +static inline void virtnet_record_rx_tstamp(const struct virtnet_info *vi, + struct sk_buff *skb) +{ + const struct virtio_net_hdr_hash_ts *h =3D skb_vnet_hdr_ht(skb); + + if (h->hash.hdr.flags & VIRTIO_NET_HDR_F_TSTAMP && + vi->enable_rx_tstamp) { + u64 ts =3D le64_to_cpu(h->tstamp); + + skb_hwtstamps(skb)->hwtstamp =3D ns_to_ktime(ts); + } +} + static void receive_buf(struct virtnet_info *vi, struct receive_queue *rq, void *buf, unsigned int len, void **ctx, unsigned int *xdp_xmit, @@ -1797,6 +1823,7 @@ static void receive_buf(struct virtnet_info *vi, stru= ct receive_queue *rq, goto frame_err; } =20 + virtnet_record_rx_tstamp(vi, skb); skb_record_rx_queue(skb, vq2rxq(rq->vq)); skb->protocol =3D eth_type_trans(skb, dev); pr_debug("Receiving skb proto 0x%04x len %i type %i\n", @@ -3512,6 +3539,28 @@ static int virtnet_get_per_queue_coalesce(struct net= _device *dev, return 0; } =20 +static int virtnet_get_ts_info(struct net_device *dev, + struct ethtool_ts_info *info) +{ + struct virtnet_info *vi =3D netdev_priv(dev); + + /* setup default software timestamp */ + ethtool_op_get_ts_info(dev, info); + + /* return rx capabilities (which may differ from current enable) */ + if (vi->has_rx_tstamp) { + info->so_timestamping |=3D SOF_TIMESTAMPING_RX_HARDWARE | + SOF_TIMESTAMPING_RAW_HARDWARE; + info->rx_filters =3D HWTSTAMP_FILTER_ALL; + } else { + info->rx_filters =3D HWTSTAMP_FILTER_NONE; + } + + info->tx_types =3D HWTSTAMP_TX_OFF; + + return 0; +} + static void virtnet_init_settings(struct net_device *dev) { struct virtnet_info *vi =3D netdev_priv(dev); @@ -3637,7 +3686,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = =3D { .get_ethtool_stats =3D virtnet_get_ethtool_stats, .set_channels =3D virtnet_set_channels, .get_channels =3D virtnet_get_channels, - .get_ts_info =3D ethtool_op_get_ts_info, + .get_ts_info =3D virtnet_get_ts_info, .get_link_ksettings =3D virtnet_get_link_ksettings, .set_link_ksettings =3D virtnet_set_link_ksettings, .set_coalesce =3D virtnet_set_coalesce, @@ -3926,6 +3975,60 @@ static void virtnet_tx_timeout(struct net_device *de= v, unsigned int txqueue) jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start))); } =20 +static int virtnet_ioctl_set_hwtstamp(struct net_device *dev, struct ifreq= *ifr) +{ + struct virtnet_info *vi =3D netdev_priv(dev); + struct hwtstamp_config tsconf; + + if (copy_from_user(&tsconf, ifr->ifr_data, sizeof(tsconf))) + return -EFAULT; + if (tsconf.flags) + return -EINVAL; + if (tsconf.tx_type !=3D HWTSTAMP_TX_OFF) + return -ERANGE; + if (tsconf.rx_filter !=3D HWTSTAMP_FILTER_NONE && + tsconf.rx_filter !=3D HWTSTAMP_FILTER_ALL) + tsconf.rx_filter =3D HWTSTAMP_FILTER_ALL; + + if (!vi->has_rx_tstamp) + tsconf.rx_filter =3D HWTSTAMP_FILTER_NONE; + else + vi->enable_rx_tstamp =3D tsconf.rx_filter =3D=3D HWTSTAMP_FILTER_ALL; + + if (copy_to_user(ifr->ifr_data, &tsconf, sizeof(tsconf))) + return -EFAULT; + + return 0; +} + +static int virtnet_ioctl_get_hwtstamp(struct net_device *dev, struct ifreq= *ifr) +{ + struct virtnet_info *vi =3D netdev_priv(dev); + struct hwtstamp_config tsconf; + + tsconf.flags =3D 0; + tsconf.rx_filter =3D vi->enable_rx_tstamp ? HWTSTAMP_FILTER_ALL : + HWTSTAMP_FILTER_NONE; + tsconf.tx_type =3D HWTSTAMP_TX_OFF; + + if (copy_to_user(ifr->ifr_data, &tsconf, sizeof(tsconf))) + return -EFAULT; + + return 0; +} + +static int virtnet_ioctl(struct net_device *dev, struct ifreq *ifr, int cm= d) +{ + switch (cmd) { + case SIOCSHWTSTAMP: + return virtnet_ioctl_set_hwtstamp(dev, ifr); + + case SIOCGHWTSTAMP: + return virtnet_ioctl_get_hwtstamp(dev, ifr); + } + return -EOPNOTSUPP; +} + static const struct net_device_ops virtnet_netdev =3D { .ndo_open =3D virtnet_open, .ndo_stop =3D virtnet_close, @@ -3942,6 +4045,7 @@ static const struct net_device_ops virtnet_netdev =3D= { .ndo_get_phys_port_name =3D virtnet_get_phys_port_name, .ndo_set_features =3D virtnet_set_features, .ndo_tx_timeout =3D virtnet_tx_timeout, + .ndo_eth_ioctl =3D virtnet_ioctl, }; =20 static void virtnet_config_changed_work(struct work_struct *work) @@ -4530,6 +4634,11 @@ static int virtnet_probe(struct virtio_device *vdev) vi->hdr_len =3D sizeof(struct virtio_net_hdr_v1_hash); } =20 + if (virtio_has_feature(vdev, VIRTIO_NET_F_RX_TSTAMP)) { + vi->has_rx_tstamp =3D true; + vi->hdr_len =3D 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 =3D true; @@ -4773,7 +4882,7 @@ static struct virtio_device_id id_table[] =3D { VIRTIO_NET_F_RSS, VIRTIO_NET_F_HASH_REPORT, VIRTIO_NET_F_NOTF_COAL, \ VIRTIO_NET_F_VQ_NOTF_COAL, \ VIRTIO_NET_F_GUEST_HDRLEN, \ - VIRTIO_NET_F_TX_HASH + VIRTIO_NET_F_TX_HASH, VIRTIO_NET_F_RX_TSTAMP =20 static unsigned int features[] =3D { VIRTNET_FEATURES, diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_ne= t.h index 698a11f8c6ab9..6a0a6f299a13b 100644 --- a/include/uapi/linux/virtio_net.h +++ b/include/uapi/linux/virtio_net.h @@ -56,6 +56,7 @@ #define VIRTIO_NET_F_MQ 22 /* Device supports Receive Flow * Steering */ #define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ +#define VIRTIO_NET_F_RX_TSTAMP 50 /* Device sends TAI receive time */ #define VIRTIO_NET_F_TX_HASH 51 /* Driver sends hash report */ #define VIRTIO_NET_F_VQ_NOTF_COAL 52 /* Device supports virtqueue notifica= tion coalescing */ #define VIRTIO_NET_F_NOTF_COAL 53 /* Device supports notifications coalesc= ing */ @@ -131,6 +132,7 @@ struct virtio_net_hdr_v1 { #define VIRTIO_NET_HDR_F_NEEDS_CSUM 1 /* Use csum_start, csum_offset */ #define VIRTIO_NET_HDR_F_DATA_VALID 2 /* Csum is valid */ #define VIRTIO_NET_HDR_F_RSC_INFO 4 /* rsc info in csum_ fields */ +#define VIRTIO_NET_HDR_F_TSTAMP 8 /* timestamp is recorded */ __u8 flags; #define VIRTIO_NET_HDR_GSO_NONE 0 /* Not a GSO frame */ #define VIRTIO_NET_HDR_GSO_TCPV4 1 /* GSO frame, IPv4 TCP (TSO) */ @@ -187,6 +189,17 @@ struct virtio_net_hdr_v1_hash { }; }; =20 +struct virtio_net_hdr_hash_ts { + struct { + struct virtio_net_hdr_v1 hdr; + __le32 value; + __le16 report; + __le16 flow_state; + } hash; + __u32 reserved; + __le64 tstamp; +}; + #ifndef VIRTIO_NET_NO_LEGACY /* This header comes first in the scatter-gather list. * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, it must --=20 2.42.0