This patch extends the XDP Tx metadata framework to include Time-Based
Scheduling (TBS) support where the NIC will schedule a packet for
transmission at a pre-determined time called launch time. The value of
launch time is communicated from user space to Ethernet driver via
launch_time field of struct xsk_tx_metadata.
Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com>
---
Documentation/netlink/specs/netdev.yaml | 4 ++++
Documentation/networking/xsk-tx-metadata.rst | 5 +++++
include/net/xdp_sock.h | 10 ++++++++++
include/net/xdp_sock_drv.h | 1 +
include/uapi/linux/if_xdp.h | 9 +++++++++
include/uapi/linux/netdev.h | 3 +++
net/core/netdev-genl.c | 2 ++
net/xdp/xsk.c | 3 +++
tools/include/uapi/linux/if_xdp.h | 9 +++++++++
tools/include/uapi/linux/netdev.h | 3 +++
tools/net/ynl/generated/netdev-user.c | 1 +
11 files changed, 50 insertions(+)
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 00439bcbd2e3..a602776bbfb4 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -66,6 +66,10 @@ definitions:
name: tx-checksum
doc:
L3 checksum HW offload is supported by the driver.
+ -
+ name: launch-time
+ doc:
+ HW Time-Based Scheduling (TBS) is supported by the driver.
attribute-sets:
-
diff --git a/Documentation/networking/xsk-tx-metadata.rst b/Documentation/networking/xsk-tx-metadata.rst
index 97ecfa480d00..e3a7486f47e2 100644
--- a/Documentation/networking/xsk-tx-metadata.rst
+++ b/Documentation/networking/xsk-tx-metadata.rst
@@ -44,6 +44,10 @@ The flags field enables the particular offload:
checksum. ``csum_start`` specifies byte offset of where the checksumming
should start and ``csum_offset`` specifies byte offset where the
device should store the computed checksum.
+- ``XDP_TXMD_FLAGS_LAUNCH_TIME``: requests HW Time-Based Scheduling (TBS)
+ offload to launch the packet at a pre-determined time. ``launch_time``
+ indicates the time which the NIC should schedule the packet for
+ transmission.
Besides the flags above, in order to trigger the offloads, the first
packet's ``struct xdp_desc`` descriptor should set ``XDP_TX_METADATA``
@@ -68,6 +72,7 @@ Refer to ``xsk-flags`` features bitmask in
- ``tx-timestamp``: device supports ``XDP_TXMD_FLAGS_TIMESTAMP``
- ``tx-checksum``: device supports ``XDP_TXMD_FLAGS_CHECKSUM``
+- ``launch-time``: device supports ``XDP_TXMD_FLAGS_LAUNCH_TIME``
See ``tools/net/ynl/samples/netdev.c`` on how to query this information.
diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h
index 3cb4dc9bd70e..f3e274830816 100644
--- a/include/net/xdp_sock.h
+++ b/include/net/xdp_sock.h
@@ -110,11 +110,16 @@ struct xdp_sock {
* indicates position where checksumming should start.
* csum_offset indicates position where checksum should be stored.
*
+ * void (*tmo_request_launch_time)(u64 launch_time, void *priv)
+ * Called when AF_XDP frame requested HW Time-Based Scheduling (TBS) offload
+ * support. launch_time indicates the time which the NIC should schedule the
+ * packet for transmission.
*/
struct xsk_tx_metadata_ops {
void (*tmo_request_timestamp)(void *priv);
u64 (*tmo_fill_timestamp)(void *priv);
void (*tmo_request_checksum)(u16 csum_start, u16 csum_offset, void *priv);
+ void (*tmo_request_launch_time)(u64 launch_time, void *priv);
};
#ifdef CONFIG_XDP_SOCKETS
@@ -170,6 +175,11 @@ static inline void xsk_tx_metadata_request(const struct xsk_tx_metadata *meta,
if (meta->flags & XDP_TXMD_FLAGS_CHECKSUM)
ops->tmo_request_checksum(meta->request.csum_start,
meta->request.csum_offset, priv);
+
+ if (ops->tmo_request_launch_time)
+ if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME)
+ ops->tmo_request_launch_time(meta->request.launch_time,
+ priv);
}
/**
diff --git a/include/net/xdp_sock_drv.h b/include/net/xdp_sock_drv.h
index 81e02de3f453..5b88559e956b 100644
--- a/include/net/xdp_sock_drv.h
+++ b/include/net/xdp_sock_drv.h
@@ -168,6 +168,7 @@ static inline void *xsk_buff_raw_get_data(struct xsk_buff_pool *pool, u64 addr)
#define XDP_TXMD_FLAGS_VALID ( \
XDP_TXMD_FLAGS_TIMESTAMP | \
XDP_TXMD_FLAGS_CHECKSUM | \
+ XDP_TXMD_FLAGS_LAUNCH_TIME | \
0)
static inline bool xsk_buff_valid_tx_metadata(struct xsk_tx_metadata *meta)
diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index d31698410410..623d34e03981 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -123,6 +123,12 @@ struct xdp_options {
*/
#define XDP_TXMD_FLAGS_CHECKSUM (1 << 1)
+/* Request HW Time-Based Scheduling (TBS) offload to launch the packet at a
+ * pre-determined time. The time which the NIC should schedule the packet for
+ * transmission is communicated via launch_time field of struct xsk_tx_metadata.
+ */
+#define XDP_TXMD_FLAGS_LAUNCH_TIME (1 << 2)
+
/* AF_XDP offloads request. 'request' union member is consumed by the driver
* when the packet is being transmitted. 'completion' union member is
* filled by the driver when the transmit completion arrives.
@@ -138,6 +144,9 @@ struct xsk_tx_metadata {
__u16 csum_start;
/* Offset from csum_start where checksum should be stored. */
__u16 csum_offset;
+
+ /* XDP_TXMD_FLAGS_LAUNCH_TIME */
+ __u64 launch_time;
} request;
struct {
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 48d5477a668c..db8b8618b29a 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -59,10 +59,13 @@ enum netdev_xdp_rx_metadata {
* by the driver.
* @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the
* driver.
+ * @NETDEV_XSK_FLAGS_TX_LAUNCH_TIME: HW Time-Based Scheduling is supported by
+ * the driver.
*/
enum netdev_xsk_flags {
NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1,
NETDEV_XSK_FLAGS_TX_CHECKSUM = 2,
+ NETDEV_XSK_FLAGS_TX_LAUNCH_TIME = 3,
/* private: */
NETDEV_XSK_FLAGS_MASK = 3,
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 10f2124e9e23..d001323b1d72 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -33,6 +33,8 @@ XDP_METADATA_KFUNC_xxx
xsk_features |= NETDEV_XSK_FLAGS_TX_TIMESTAMP;
if (netdev->xsk_tx_metadata_ops->tmo_request_checksum)
xsk_features |= NETDEV_XSK_FLAGS_TX_CHECKSUM;
+ if (netdev->xsk_tx_metadata_ops->tmo_request_launch_time)
+ xsk_features |= NETDEV_XSK_FLAGS_TX_LAUNCH_TIME;
}
if (nla_put_u32(rsp, NETDEV_A_DEV_IFINDEX, netdev->ifindex) ||
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index 281d49b4fca4..ad98ac6adb43 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -751,6 +751,9 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
goto free_err;
}
}
+
+ if (meta->flags & XDP_TXMD_FLAGS_LAUNCH_TIME)
+ skb->skb_mstamp_ns = meta->request.launch_time;
}
}
diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h
index 638c606dfa74..80462125c5c3 100644
--- a/tools/include/uapi/linux/if_xdp.h
+++ b/tools/include/uapi/linux/if_xdp.h
@@ -123,6 +123,12 @@ struct xdp_options {
*/
#define XDP_TXMD_FLAGS_CHECKSUM (1 << 1)
+/* Request HW Time-Based Scheduling (TBS) offload to launch the packet at a
+ * pre-determined time. The time which the NIC should schedule the packet for
+ * transmission is communicated via launch_time field of struct xsk_tx_metadata.
+ */
+#define XDP_TXMD_FLAGS_LAUNCH_TIME (1 << 2)
+
/* AF_XDP offloads request. 'request' union member is consumed by the driver
* when the packet is being transmitted. 'completion' union member is
* filled by the driver when the transmit completion arrives.
@@ -138,6 +144,9 @@ struct xsk_tx_metadata {
__u16 csum_start;
/* Offset from csum_start where checksum should be stored. */
__u16 csum_offset;
+
+ /* XDP_TXMD_FLAGS_LAUNCH_TIME */
+ __u64 launch_time;
} request;
struct {
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 48d5477a668c..db8b8618b29a 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -59,10 +59,13 @@ enum netdev_xdp_rx_metadata {
* by the driver.
* @NETDEV_XSK_FLAGS_TX_CHECKSUM: L3 checksum HW offload is supported by the
* driver.
+ * @NETDEV_XSK_FLAGS_TX_LAUNCH_TIME: HW Time-Based Scheduling is supported by
+ * the driver.
*/
enum netdev_xsk_flags {
NETDEV_XSK_FLAGS_TX_TIMESTAMP = 1,
NETDEV_XSK_FLAGS_TX_CHECKSUM = 2,
+ NETDEV_XSK_FLAGS_TX_LAUNCH_TIME = 3,
/* private: */
NETDEV_XSK_FLAGS_MASK = 3,
diff --git a/tools/net/ynl/generated/netdev-user.c b/tools/net/ynl/generated/netdev-user.c
index 6283d87dad37..bb4136d64f57 100644
--- a/tools/net/ynl/generated/netdev-user.c
+++ b/tools/net/ynl/generated/netdev-user.c
@@ -61,6 +61,7 @@ const char *netdev_xdp_rx_metadata_str(enum netdev_xdp_rx_metadata value)
static const char * const netdev_xsk_flags_strmap[] = {
[0] = "tx-timestamp",
[1] = "tx-checksum",
+ [2] = "launch-time"
};
const char *netdev_xsk_flags_str(enum netdev_xsk_flags value)
--
2.34.1On Fri, 1 Dec 2023 00:20:26 +0800 Song Yoong Siang wrote: > + name: launch-time > + doc: > + HW Time-Based Scheduling (TBS) is supported by the driver. Does this mean fifo "gating" or HW can do reordering?
On Saturday, December 2, 2023 11:29 AM, Jakub Kicinski wrote: >On Fri, 1 Dec 2023 00:20:26 +0800 Song Yoong Siang wrote: >> + name: launch-time >> + doc: >> + HW Time-Based Scheduling (TBS) is supported by the driver. > >Does this mean fifo "gating" or HW can do reordering? Yes, HW will do reordering according to the value of launch time.
Song Yoong Siang wrote: > This patch extends the XDP Tx metadata framework to include Time-Based > Scheduling (TBS) support where the NIC will schedule a packet for > transmission at a pre-determined time called launch time. The value of > launch time is communicated from user space to Ethernet driver via > launch_time field of struct xsk_tx_metadata. > > Suggested-by: Stanislav Fomichev <sdf@google.com> > Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com> > --- > Documentation/netlink/specs/netdev.yaml | 4 ++++ > Documentation/networking/xsk-tx-metadata.rst | 5 +++++ > include/net/xdp_sock.h | 10 ++++++++++ > include/net/xdp_sock_drv.h | 1 + > include/uapi/linux/if_xdp.h | 9 +++++++++ > include/uapi/linux/netdev.h | 3 +++ > net/core/netdev-genl.c | 2 ++ > net/xdp/xsk.c | 3 +++ > tools/include/uapi/linux/if_xdp.h | 9 +++++++++ > tools/include/uapi/linux/netdev.h | 3 +++ > tools/net/ynl/generated/netdev-user.c | 1 + > 11 files changed, 50 insertions(+) > > diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml > index 00439bcbd2e3..a602776bbfb4 100644 > --- a/Documentation/netlink/specs/netdev.yaml > +++ b/Documentation/netlink/specs/netdev.yaml > @@ -66,6 +66,10 @@ definitions: > name: tx-checksum > doc: > L3 checksum HW offload is supported by the driver. > + - > + name: launch-time > + doc: > + HW Time-Based Scheduling (TBS) is supported by the driver. Can we avoid introducing another term? We already have too many: launchtime, earliest delivery time (EDT), SO_TXTIME, pacing offload, earliest txtime first (ETF).
On Friday, December 1, 2023 4:29 AM, Willem de Bruijn wrote: >Song Yoong Siang wrote: >> This patch extends the XDP Tx metadata framework to include Time-Based >> Scheduling (TBS) support where the NIC will schedule a packet for >> transmission at a pre-determined time called launch time. The value of >> launch time is communicated from user space to Ethernet driver via >> launch_time field of struct xsk_tx_metadata. >> >> Suggested-by: Stanislav Fomichev <sdf@google.com> >> Signed-off-by: Song Yoong Siang <yoong.siang.song@intel.com> >> --- >> Documentation/netlink/specs/netdev.yaml | 4 ++++ >> Documentation/networking/xsk-tx-metadata.rst | 5 +++++ >> include/net/xdp_sock.h | 10 ++++++++++ >> include/net/xdp_sock_drv.h | 1 + >> include/uapi/linux/if_xdp.h | 9 +++++++++ >> include/uapi/linux/netdev.h | 3 +++ >> net/core/netdev-genl.c | 2 ++ >> net/xdp/xsk.c | 3 +++ >> tools/include/uapi/linux/if_xdp.h | 9 +++++++++ >> tools/include/uapi/linux/netdev.h | 3 +++ >> tools/net/ynl/generated/netdev-user.c | 1 + >> 11 files changed, 50 insertions(+) >> >> diff --git a/Documentation/netlink/specs/netdev.yaml >b/Documentation/netlink/specs/netdev.yaml >> index 00439bcbd2e3..a602776bbfb4 100644 >> --- a/Documentation/netlink/specs/netdev.yaml >> +++ b/Documentation/netlink/specs/netdev.yaml >> @@ -66,6 +66,10 @@ definitions: >> name: tx-checksum >> doc: >> L3 checksum HW offload is supported by the driver. >> + - >> + name: launch-time >> + doc: >> + HW Time-Based Scheduling (TBS) is supported by the driver. > >Can we avoid introducing another term? We already have too many: >launchtime, earliest delivery time (EDT), SO_TXTIME, >pacing offload, earliest txtime first (ETF). > Sure. I will change TBS to ETF in my V2 so that it is aligned with etf command in tc application.
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