On Thu, 29 Jan 2026 09:06:42 +0100, Steffen Trumtrar <[email protected]> wrote: > Add optional hardware rx timestamp offload for virtio-net. > > Introduce virtio feature VIRTIO_NET_F_TSTAMP. If negotiated, the > virtio-net header is expanded with room for a timestamp. > > To get and set the hwtstamp the functions ndo_hwtstamp_set/get need > to be implemented. This allows filtering the packets and only time stamp > the packets where the filter matches. This way, the timestamping can > be en/disabled at runtime. > > Tested: > guest: ./timestamping eth0 \ > SOF_TIMESTAMPING_RAW_HARDWARE \ > SOF_TIMESTAMPING_RX_HARDWARE > host: nc -4 -u 192.168.1.1 319 > > Signed-off-by: Steffen Trumtrar <[email protected]> > > -- > Changes to last version: > - rework series to use flow filters > - add new struct virtio_net_hdr_v1_hash_tunnel_ts > - original work done by: Willem de Bruijn <[email protected]> > --- > drivers/net/virtio_net.c | 136 > ++++++++++++++++++++++++++++++++++++---- > include/uapi/linux/virtio_net.h | 9 +++ > 2 files changed, 133 insertions(+), 12 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 1bb3aeca66c6e..4e8d9b20c1b34 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -429,6 +429,9 @@ struct virtnet_info { > struct virtio_net_rss_config_trailer rss_trailer; > u8 rss_hash_key_data[VIRTIO_NET_RSS_MAX_KEY_SIZE]; > > + /* Device passes time stamps from the driver */ > + bool has_tstamp; > + > /* Has control virtqueue */ > bool has_cvq; > > @@ -475,6 +478,8 @@ struct virtnet_info { > > struct control_buf *ctrl; > > + struct kernel_hwtstamp_config tstamp_config; > + > /* Ethtool settings */ > u8 duplex; > u32 speed; > @@ -511,6 +516,7 @@ struct virtio_net_common_hdr { > struct virtio_net_hdr_mrg_rxbuf mrg_hdr; > struct virtio_net_hdr_v1_hash hash_v1_hdr; > struct virtio_net_hdr_v1_hash_tunnel tnl_hdr; > + struct virtio_net_hdr_v1_hash_tunnel_ts ts_hdr; > }; > }; > > @@ -682,6 +688,13 @@ skb_vnet_common_hdr(struct sk_buff *skb) > return (struct virtio_net_common_hdr *)skb->cb; > } > > +static inline struct virtio_net_hdr_v1_hash_tunnel_ts > *skb_vnet_hdr_ts(struct sk_buff *skb) > +{ > + BUILD_BUG_ON(sizeof(struct virtio_net_hdr_v1_hash_tunnel_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 > @@ -2560,6 +2573,15 @@ virtio_net_hash_value(const struct > virtio_net_hdr_v1_hash *hdr_hash) > (__le16_to_cpu(hdr_hash->hash_value_hi) << 16); > } > > +static inline u64 > +virtio_net_tstamp_value(const struct virtio_net_hdr_v1_hash_tunnel_ts > *hdr_hash_ts) > +{ > + return (u64)__le16_to_cpu(hdr_hash_ts->tstamp_0) | > + ((u64)__le16_to_cpu(hdr_hash_ts->tstamp_1) << 16) | > + ((u64)__le16_to_cpu(hdr_hash_ts->tstamp_2) << 32) | > + ((u64)__le16_to_cpu(hdr_hash_ts->tstamp_3) << 48); > +} > + > static void virtio_skb_set_hash(const struct virtio_net_hdr_v1_hash > *hdr_hash, > struct sk_buff *skb) > { > @@ -2589,6 +2611,18 @@ static void virtio_skb_set_hash(const struct > virtio_net_hdr_v1_hash *hdr_hash, > skb_set_hash(skb, virtio_net_hash_value(hdr_hash), rss_hash_type); > } > > +static inline void virtnet_record_rx_tstamp(const struct virtnet_info *vi, > + struct sk_buff *skb) > +{ > + struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb); > + const struct virtio_net_hdr_v1_hash_tunnel_ts *h = skb_vnet_hdr_ts(skb); > + u64 ts; > + > + ts = virtio_net_tstamp_value(h); > + memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps)); > + shhwtstamps->hwtstamp = ns_to_ktime(ts); > +} > + > static void virtnet_receive_done(struct virtnet_info *vi, struct > receive_queue *rq, > struct sk_buff *skb, u8 flags) > { > @@ -2617,6 +2651,8 @@ static void virtnet_receive_done(struct virtnet_info > *vi, struct receive_queue * > goto frame_err; > } > > + if (vi->has_tstamp && vi->tstamp_config.rx_filter != > HWTSTAMP_FILTER_NONE) > + virtnet_record_rx_tstamp(vi, skb); > skb_record_rx_queue(skb, vq2rxq(rq->vq)); > skb->protocol = eth_type_trans(skb, dev); > pr_debug("Receiving skb proto 0x%04x len %i type %i\n", > @@ -3321,7 +3357,7 @@ static int xmit_skb(struct send_queue *sq, struct > sk_buff *skb, bool orphan) > { > const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; > struct virtnet_info *vi = sq->vq->vdev->priv; > - struct virtio_net_hdr_v1_hash_tunnel *hdr; > + struct virtio_net_hdr_v1_hash_tunnel_ts *hdr; > int num_sg; > unsigned hdr_len = vi->hdr_len; > bool can_push; > @@ -3329,8 +3365,8 @@ static int xmit_skb(struct send_queue *sq, struct > sk_buff *skb, bool orphan) > pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); > > /* Make sure it's safe to cast between formats */ > - BUILD_BUG_ON(__alignof__(*hdr) != __alignof__(hdr->hash_hdr)); > - BUILD_BUG_ON(__alignof__(*hdr) != __alignof__(hdr->hash_hdr.hdr)); > + BUILD_BUG_ON(__alignof__(*hdr) != __alignof__(hdr->tnl.hash_hdr)); > + BUILD_BUG_ON(__alignof__(*hdr) != __alignof__(hdr->tnl.hash_hdr.hdr)); > > can_push = vi->any_header_sg && > !((unsigned long)skb->data & (__alignof__(*hdr) - 1)) && > @@ -3338,18 +3374,18 @@ static int xmit_skb(struct send_queue *sq, struct > sk_buff *skb, bool orphan) > /* Even if we can, don't push here yet as this would skew > * csum_start offset below. */ > if (can_push) > - hdr = (struct virtio_net_hdr_v1_hash_tunnel *)(skb->data - > - hdr_len); > + hdr = (struct virtio_net_hdr_v1_hash_tunnel_ts *)(skb->data - > + hdr_len); > else > - hdr = &skb_vnet_common_hdr(skb)->tnl_hdr; > + hdr = &skb_vnet_common_hdr(skb)->ts_hdr; > > - if (virtio_net_hdr_tnl_from_skb(skb, hdr, vi->tx_tnl, > + if (virtio_net_hdr_tnl_from_skb(skb, &hdr->tnl, vi->tx_tnl, > virtio_is_little_endian(vi->vdev), 0, > false)) > return -EPROTO; > > if (vi->mergeable_rx_bufs) > - hdr->hash_hdr.hdr.num_buffers = 0; > + hdr->tnl.hash_hdr.hdr.num_buffers = 0; > > sg_init_table(sq->sg, skb_shinfo(skb)->nr_frags + (can_push ? 1 : 2)); > if (can_push) { > @@ -5563,6 +5599,22 @@ static int virtnet_get_per_queue_coalesce(struct > net_device *dev, > return 0; > } > > +static int virtnet_get_ts_info(struct net_device *dev, > + struct kernel_ethtool_ts_info *info) > +{ > + /* setup default software timestamp */ > + ethtool_op_get_ts_info(dev, info); > + > + info->rx_filters = (BIT(HWTSTAMP_FILTER_NONE) | > + BIT(HWTSTAMP_FILTER_PTP_V1_L4_SYNC) | > + BIT(HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ) | > + BIT(HWTSTAMP_FILTER_ALL)); > + > + info->tx_types = HWTSTAMP_TX_OFF; > + > + return 0; > +} > + > static void virtnet_init_settings(struct net_device *dev) > { > struct virtnet_info *vi = netdev_priv(dev); > @@ -5658,7 +5710,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = { > .get_ethtool_stats = virtnet_get_ethtool_stats, > .set_channels = virtnet_set_channels, > .get_channels = virtnet_get_channels, > - .get_ts_info = ethtool_op_get_ts_info, > + .get_ts_info = virtnet_get_ts_info, > .get_link_ksettings = virtnet_get_link_ksettings, > .set_link_ksettings = virtnet_set_link_ksettings, > .set_coalesce = virtnet_set_coalesce, > @@ -6242,6 +6294,58 @@ static void virtnet_tx_timeout(struct net_device *dev, > unsigned int txqueue) > jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start))); > } > > +static int virtnet_hwtstamp_get(struct net_device *dev, > + struct kernel_hwtstamp_config *tstamp_config) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + > + if (!netif_running(dev)) > + return -EINVAL; > + > + *tstamp_config = vi->tstamp_config; > + > + return 0; > +} > + > +static int virtnet_hwtstamp_set(struct net_device *dev, > + struct kernel_hwtstamp_config *tstamp_config, > + struct netlink_ext_ack *extack) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + > + if (!netif_running(dev)) > + return -EINVAL; > + > + switch (tstamp_config->rx_filter) { > + case HWTSTAMP_FILTER_PTP_V1_L4_SYNC: > + case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ: > + break; > + case HWTSTAMP_FILTER_PTP_V2_EVENT: > + case HWTSTAMP_FILTER_PTP_V2_L2_EVENT: > + case HWTSTAMP_FILTER_PTP_V2_L4_EVENT: > + case HWTSTAMP_FILTER_PTP_V2_SYNC: > + case HWTSTAMP_FILTER_PTP_V2_L2_SYNC: > + case HWTSTAMP_FILTER_PTP_V2_L4_SYNC: > + case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ: > + case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ: > + case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ: > + tstamp_config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT; > + break; > + case HWTSTAMP_FILTER_NONE: > + break; > + case HWTSTAMP_FILTER_ALL: > + tstamp_config->rx_filter = HWTSTAMP_FILTER_ALL; > + break; > + default: > + tstamp_config->rx_filter = HWTSTAMP_FILTER_ALL; > + return -ERANGE; > + } > + > + vi->tstamp_config = *tstamp_config; > + > + return 0; > +} > + > static int virtnet_init_irq_moder(struct virtnet_info *vi) > { > u8 profile_flags = 0, coal_flags = 0; > @@ -6289,6 +6393,8 @@ static const struct net_device_ops virtnet_netdev = { > .ndo_get_phys_port_name = virtnet_get_phys_port_name, > .ndo_set_features = virtnet_set_features, > .ndo_tx_timeout = virtnet_tx_timeout, > + .ndo_hwtstamp_set = virtnet_hwtstamp_set, > + .ndo_hwtstamp_get = virtnet_hwtstamp_get, > }; > > static void virtnet_config_changed_work(struct work_struct *work) > @@ -6911,6 +7017,9 @@ static int virtnet_probe(struct virtio_device *vdev) > if (virtio_has_feature(vdev, VIRTIO_NET_F_HASH_REPORT)) > vi->has_rss_hash_report = true; > > + if (virtio_has_feature(vdev, VIRTIO_NET_F_TSTAMP)) > + vi->has_tstamp = true; > + > if (virtio_has_feature(vdev, VIRTIO_NET_F_RSS)) { > vi->has_rss = true; > > @@ -6945,8 +7054,10 @@ static int virtnet_probe(struct virtio_device *vdev) > dev->xdp_metadata_ops = &virtnet_xdp_metadata_ops; > } > > - if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO) || > - virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO)) > + if (vi->has_tstamp) > + vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash_tunnel_ts); > + else if (virtio_has_feature(vdev, VIRTIO_NET_F_GUEST_UDP_TUNNEL_GSO) || > + virtio_has_feature(vdev, VIRTIO_NET_F_HOST_UDP_TUNNEL_GSO)) > vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash_tunnel); > else if (vi->has_rss_hash_report) > vi->hdr_len = sizeof(struct virtio_net_hdr_v1_hash); > @@ -7269,7 +7380,8 @@ static struct virtio_device_id id_table[] = { > VIRTIO_NET_F_SPEED_DUPLEX, VIRTIO_NET_F_STANDBY, \ > 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_DEVICE_STATS > + VIRTIO_NET_F_GUEST_HDRLEN, VIRTIO_NET_F_DEVICE_STATS, \ > + VIRTIO_NET_F_TSTAMP > > static unsigned int features[] = { > VIRTNET_FEATURES, > diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.h > index 1db45b01532b5..9f967575956b8 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_TSTAMP 49 /* Device sends TAI receive time */ > #define VIRTIO_NET_F_DEVICE_STATS 50 /* Device can provide device-level > statistics. */ > #define VIRTIO_NET_F_VQ_NOTF_COAL 52 /* Device supports virtqueue > notification coalescing */ > #define VIRTIO_NET_F_NOTF_COAL 53 /* Device supports > notifications coalescing */ > @@ -215,6 +216,14 @@ struct virtio_net_hdr_v1_hash_tunnel { > __le16 inner_nh_offset; > }; > > +struct virtio_net_hdr_v1_hash_tunnel_ts { > + struct virtio_net_hdr_v1_hash_tunnel tnl; > + __le16 tstamp_0; > + __le16 tstamp_1; > + __le16 tstamp_2; > + __le16 tstamp_3; > +};
Since patch #1 used this struct, this one should be placed first in the series. Also, has the virtio specification process accepted such a draft proposal? Thanks > + > #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 > > -- > 2.52.0 >
