From: Willem de Bruijn <[email protected]>
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 <[email protected]>
Co-developed-by: Steffen Trumtrar <[email protected]>
Signed-off-by: Steffen Trumtrar <[email protected]>
--
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;
+ /* 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;
@@ -384,6 +390,13 @@ skb_vnet_common_hdr(struct sk_buff *skb)
return (struct virtio_net_common_hdr *)skb->cb;
}
+static inline struct virtio_net_hdr_hash_ts *skb_vnet_hdr_ht(struct sk_buff *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);
}
+static inline void virtnet_record_rx_tstamp(const struct virtnet_info *vi,
+ struct sk_buff *skb)
+{
+ const struct virtio_net_hdr_hash_ts *h = skb_vnet_hdr_ht(skb);
+
+ if (h->hash.hdr.flags & VIRTIO_NET_HDR_F_TSTAMP &&
+ vi->enable_rx_tstamp) {
+ u64 ts = le64_to_cpu(h->tstamp);
+
+ skb_hwtstamps(skb)->hwtstamp = 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, struct receive_queue *rq,
goto frame_err;
}
+ 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",
@@ -3512,6 +3539,28 @@ static int virtnet_get_per_queue_coalesce(struct net_device *dev,
return 0;
}
+static int virtnet_get_ts_info(struct net_device *dev,
+ struct ethtool_ts_info *info)
+{
+ struct virtnet_info *vi = 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 |= SOF_TIMESTAMPING_RX_HARDWARE |
+ SOF_TIMESTAMPING_RAW_HARDWARE;
+ info->rx_filters = HWTSTAMP_FILTER_ALL;
+ } else {
+ info->rx_filters = HWTSTAMP_FILTER_NONE;
+ }
+
+ info->tx_types = HWTSTAMP_TX_OFF;
+
+ return 0;
+}
+
static void virtnet_init_settings(struct net_device *dev)
{
struct virtnet_info *vi = netdev_priv(dev);
@@ -3637,7 +3686,7 @@ 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,
@@ -3926,6 +3975,60 @@ static void virtnet_tx_timeout(struct net_device *dev, unsigned int txqueue)
jiffies_to_usecs(jiffies - READ_ONCE(txq->trans_start)));
}
+static int virtnet_ioctl_set_hwtstamp(struct net_device *dev, struct ifreq *ifr)
+{
+ struct virtnet_info *vi = 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 != HWTSTAMP_TX_OFF)
+ return -ERANGE;
+ if (tsconf.rx_filter != HWTSTAMP_FILTER_NONE &&
+ tsconf.rx_filter != HWTSTAMP_FILTER_ALL)
+ tsconf.rx_filter = HWTSTAMP_FILTER_ALL;
+
+ if (!vi->has_rx_tstamp)
+ tsconf.rx_filter = HWTSTAMP_FILTER_NONE;
+ else
+ vi->enable_rx_tstamp = tsconf.rx_filter == 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 = netdev_priv(dev);
+ struct hwtstamp_config tsconf;
+
+ tsconf.flags = 0;
+ tsconf.rx_filter = vi->enable_rx_tstamp ? HWTSTAMP_FILTER_ALL :
+ HWTSTAMP_FILTER_NONE;
+ tsconf.tx_type = 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 cmd)
+{
+ 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 = {
.ndo_open = virtnet_open,
.ndo_stop = virtnet_close,
@@ -3942,6 +4045,7 @@ 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_eth_ioctl = virtnet_ioctl,
};
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 = sizeof(struct virtio_net_hdr_v1_hash);
}
+ if (virtio_has_feature(vdev, VIRTIO_NET_F_RX_TSTAMP)) {
+ vi->has_rx_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;
@@ -4773,7 +4882,7 @@ static struct virtio_device_id id_table[] = {
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
static unsigned int features[] = {
VIRTNET_FEATURES,
diff --git a/include/uapi/linux/virtio_net.h b/include/uapi/linux/virtio_net.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 notification coalescing */
#define VIRTIO_NET_F_NOTF_COAL 53 /* Device supports notifications coalescing */
@@ -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 {
};
};
+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
--
2.42.0