[PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[Mina Almasry]

From: YiFei Zhu <zhuyifei@google.com>

The logic is similar to idpf_rx_hwtstamp, but the data is exported
as a BPF kfunc instead of appended to an skb to support grabbing
timestamps in xsk packets.

A idpf_queue_has(PTP, rxq) condition is added to check the queue
supports PTP similar to idpf_rx_process_skb_fields.

Tested using an xsk connection and checking xdp timestamps are
retreivable in received packets.

Cc: intel-wired-lan@lists.osuosl.org
Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

---

v4: https://lore.kernel.org/netdev/20251219202957.2309698-1-almasrymina@google.com/
- Fix indentation (lobakin)
- I kept the (u64) casts for all bit shifted bits in idpf_xdp_get_qw3
  and friends as I see all idpf_xdp_get_qw* functions do the cast in all
  bit-shifted variables.

v3: https://lore.kernel.org/netdev/20251218022948.3288897-1-almasrymina@google.com/
- Do the idpf_queue_has(PTP) check before we read qw1 (lobakin)
- Fix _qw1 not copying over ts_low on on !__LIBETH_WORD_ACCESS systems
  (AI)

v2: https://lore.kernel.org/netdev/20251122140839.3922015-1-almasrymina@google.com/
- Fixed alphabetical ordering
- Use the xdp desc type instead of virtchnl one (required some added
  helpers)

---
 drivers/net/ethernet/intel/idpf/xdp.c | 31 +++++++++++++++++++++++++++
 drivers/net/ethernet/intel/idpf/xdp.h | 20 +++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/drivers/net/ethernet/intel/idpf/xdp.c b/drivers/net/ethernet/intel/idpf/xdp.c
index 958d16f87424..0916d201bf98 100644
--- a/drivers/net/ethernet/intel/idpf/xdp.c
+++ b/drivers/net/ethernet/intel/idpf/xdp.c
@@ -2,6 +2,7 @@
 /* Copyright (C) 2025 Intel Corporation */
 
 #include "idpf.h"
+#include "idpf_ptp.h"
 #include "idpf_virtchnl.h"
 #include "xdp.h"
 #include "xsk.h"
@@ -391,8 +392,38 @@ static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
 				    pt);
 }
 
+static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
+{
+	const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
+	struct idpf_xdp_rx_desc desc __uninitialized;
+	const struct idpf_rx_queue *rxq;
+	u64 cached_time, ts_ns;
+	u32 ts_high;
+
+	rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
+
+	if (!idpf_queue_has(PTP, rxq))
+		return -ENODATA;
+
+	idpf_xdp_get_qw1(&desc, xdp->desc);
+
+	if (!(idpf_xdp_rx_ts_low(&desc) & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
+		return -ENODATA;
+
+	cached_time = READ_ONCE(rxq->cached_phc_time);
+
+	idpf_xdp_get_qw3(&desc, xdp->desc);
+
+	ts_high = idpf_xdp_rx_ts_high(&desc);
+	ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time, ts_high);
+
+	*timestamp = ts_ns;
+	return 0;
+}
+
 static const struct xdp_metadata_ops idpf_xdpmo = {
 	.xmo_rx_hash		= idpf_xdpmo_rx_hash,
+	.xmo_rx_timestamp	= idpf_xdpmo_rx_timestamp,
 };
 
 void idpf_xdp_set_features(const struct idpf_vport *vport)
diff --git a/drivers/net/ethernet/intel/idpf/xdp.h b/drivers/net/ethernet/intel/idpf/xdp.h
index 479f5ef3c604..1748a0d73547 100644
--- a/drivers/net/ethernet/intel/idpf/xdp.h
+++ b/drivers/net/ethernet/intel/idpf/xdp.h
@@ -112,11 +112,13 @@ struct idpf_xdp_rx_desc {
 	aligned_u64		qw1;
 #define IDPF_XDP_RX_BUF		GENMASK_ULL(47, 32)
 #define IDPF_XDP_RX_EOP		BIT_ULL(1)
+#define IDPF_XDP_RX_TS_LOW	GENMASK_ULL(31, 24)
 
 	aligned_u64		qw2;
 #define IDPF_XDP_RX_HASH	GENMASK_ULL(31, 0)
 
 	aligned_u64		qw3;
+#define IDPF_XDP_RX_TS_HIGH	GENMASK_ULL(63, 32)
 } __aligned(4 * sizeof(u64));
 static_assert(sizeof(struct idpf_xdp_rx_desc) ==
 	      sizeof(struct virtchnl2_rx_flex_desc_adv_nic_3));
@@ -128,6 +130,8 @@ static_assert(sizeof(struct idpf_xdp_rx_desc) ==
 #define idpf_xdp_rx_buf(desc)	FIELD_GET(IDPF_XDP_RX_BUF, (desc)->qw1)
 #define idpf_xdp_rx_eop(desc)	!!((desc)->qw1 & IDPF_XDP_RX_EOP)
 #define idpf_xdp_rx_hash(desc)	FIELD_GET(IDPF_XDP_RX_HASH, (desc)->qw2)
+#define idpf_xdp_rx_ts_low(desc)	FIELD_GET(IDPF_XDP_RX_TS_LOW, (desc)->qw1)
+#define idpf_xdp_rx_ts_high(desc)	FIELD_GET(IDPF_XDP_RX_TS_HIGH, (desc)->qw3)
 
 static inline void
 idpf_xdp_get_qw0(struct idpf_xdp_rx_desc *desc,
@@ -149,6 +153,9 @@ idpf_xdp_get_qw1(struct idpf_xdp_rx_desc *desc,
 	desc->qw1 = ((const typeof(desc))rxd)->qw1;
 #else
 	desc->qw1 = ((u64)le16_to_cpu(rxd->buf_id) << 32) |
+		    ((u64)rxd->ts_low << 24) |
+		    ((u64)rxd->fflags1 << 16) |
+		    ((u64)rxd->status_err1 << 8) |
 		    rxd->status_err0_qw1;
 #endif
 }
@@ -166,6 +173,19 @@ idpf_xdp_get_qw2(struct idpf_xdp_rx_desc *desc,
 #endif
 }
 
+static inline void
+idpf_xdp_get_qw3(struct idpf_xdp_rx_desc *desc,
+		 const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
+{
+#ifdef __LIBETH_WORD_ACCESS
+	desc->qw3 = ((const typeof(desc))rxd)->qw3;
+#else
+	desc->qw3 = ((u64)le32_to_cpu(rxd->ts_high) << 32) |
+		    ((u64)le16_to_cpu(rxd->fmd6) << 16) |
+		    le16_to_cpu(rxd->l2tag1);
+#endif
+}
+
 void idpf_xdp_set_features(const struct idpf_vport *vport);
 
 int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp);

base-commit: 7b8e9264f55a9c320f398e337d215e68cca50131
-- 
2.52.0.351.gbe84eed79e-goog

Re: [PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[Alexander Lobakin]

From: Mina Almasry <almasrymina@google.com>
Date: Tue, 23 Dec 2025 19:46:46 +0000

> From: YiFei Zhu <zhuyifei@google.com>
> 
> The logic is similar to idpf_rx_hwtstamp, but the data is exported
> as a BPF kfunc instead of appended to an skb to support grabbing
> timestamps in xsk packets.
> 
> A idpf_queue_has(PTP, rxq) condition is added to check the queue
> supports PTP similar to idpf_rx_process_skb_fields.
> 
> Tested using an xsk connection and checking xdp timestamps are
> retreivable in received packets.
> 
> Cc: intel-wired-lan@lists.osuosl.org
> Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

Thanks,
Olek

Re: [PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[Simon Horman]

On Tue, Dec 23, 2025 at 07:46:46PM +0000, Mina Almasry wrote:
> From: YiFei Zhu <zhuyifei@google.com>
> 
> The logic is similar to idpf_rx_hwtstamp, but the data is exported
> as a BPF kfunc instead of appended to an skb to support grabbing
> timestamps in xsk packets.
> 
> A idpf_queue_has(PTP, rxq) condition is added to check the queue
> supports PTP similar to idpf_rx_process_skb_fields.
> 
> Tested using an xsk connection and checking xdp timestamps are
> retreivable in received packets.
> 
> Cc: intel-wired-lan@lists.osuosl.org
> Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [Intel-wired-lan] [PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[Paul Menzel]

Dear Mina,


Thank you for your patch. Some minor comments, should you resend.

Am 23.12.25 um 20:46 schrieb Mina Almasry via Intel-wired-lan:
> From: YiFei Zhu <zhuyifei@google.com>
> 
> The logic is similar to idpf_rx_hwtstamp, but the data is exported
> as a BPF kfunc instead of appended to an skb to support grabbing
> timestamps in xsk packets.
> 
> A idpf_queue_has(PTP, rxq) condition is added to check the queue
> supports PTP similar to idpf_rx_process_skb_fields.
> 
> Tested using an xsk connection and checking xdp timestamps are
> retreivable in received packets.

retr*ie*vable

It’d be great if you could share the commands.

> Cc: intel-wired-lan@lists.osuosl.org
> Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
> 
> ---
> 
> v4: https://lore.kernel.org/netdev/20251219202957.2309698-1-almasrymina@google.com/
> - Fix indentation (lobakin)
> - I kept the (u64) casts for all bit shifted bits in idpf_xdp_get_qw3
>    and friends as I see all idpf_xdp_get_qw* functions do the cast in all
>    bit-shifted variables.
> 
> v3: https://lore.kernel.org/netdev/20251218022948.3288897-1-almasrymina@google.com/
> - Do the idpf_queue_has(PTP) check before we read qw1 (lobakin)
> - Fix _qw1 not copying over ts_low on on !__LIBETH_WORD_ACCESS systems
>    (AI)
> 
> v2: https://lore.kernel.org/netdev/20251122140839.3922015-1-almasrymina@google.com/
> - Fixed alphabetical ordering
> - Use the xdp desc type instead of virtchnl one (required some added
>    helpers)
> 
> ---
>   drivers/net/ethernet/intel/idpf/xdp.c | 31 +++++++++++++++++++++++++++
>   drivers/net/ethernet/intel/idpf/xdp.h | 20 +++++++++++++++++
>   2 files changed, 51 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/xdp.c b/drivers/net/ethernet/intel/idpf/xdp.c
> index 958d16f87424..0916d201bf98 100644
> --- a/drivers/net/ethernet/intel/idpf/xdp.c
> +++ b/drivers/net/ethernet/intel/idpf/xdp.c
> @@ -2,6 +2,7 @@
>   /* Copyright (C) 2025 Intel Corporation */
>   
>   #include "idpf.h"
> +#include "idpf_ptp.h"
>   #include "idpf_virtchnl.h"
>   #include "xdp.h"
>   #include "xsk.h"
> @@ -391,8 +392,38 @@ static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
>   				    pt);
>   }
>   
> +static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
> +{
> +	const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
> +	struct idpf_xdp_rx_desc desc __uninitialized;
> +	const struct idpf_rx_queue *rxq;
> +	u64 cached_time, ts_ns;
> +	u32 ts_high;
> +
> +	rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
> +
> +	if (!idpf_queue_has(PTP, rxq))
> +		return -ENODATA;
> +
> +	idpf_xdp_get_qw1(&desc, xdp->desc);
> +
> +	if (!(idpf_xdp_rx_ts_low(&desc) & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
> +		return -ENODATA;
> +
> +	cached_time = READ_ONCE(rxq->cached_phc_time);
> +
> +	idpf_xdp_get_qw3(&desc, xdp->desc);
> +
> +	ts_high = idpf_xdp_rx_ts_high(&desc);
> +	ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time, ts_high);
> +
> +	*timestamp = ts_ns;
> +	return 0;
> +}
> +
>   static const struct xdp_metadata_ops idpf_xdpmo = {
>   	.xmo_rx_hash		= idpf_xdpmo_rx_hash,
> +	.xmo_rx_timestamp	= idpf_xdpmo_rx_timestamp,

Append the unit?

>   };
>   
>   void idpf_xdp_set_features(const struct idpf_vport *vport)
> diff --git a/drivers/net/ethernet/intel/idpf/xdp.h b/drivers/net/ethernet/intel/idpf/xdp.h
> index 479f5ef3c604..1748a0d73547 100644
> --- a/drivers/net/ethernet/intel/idpf/xdp.h
> +++ b/drivers/net/ethernet/intel/idpf/xdp.h
> @@ -112,11 +112,13 @@ struct idpf_xdp_rx_desc {
>   	aligned_u64		qw1;
>   #define IDPF_XDP_RX_BUF		GENMASK_ULL(47, 32)
>   #define IDPF_XDP_RX_EOP		BIT_ULL(1)
> +#define IDPF_XDP_RX_TS_LOW	GENMASK_ULL(31, 24)
>   
>   	aligned_u64		qw2;
>   #define IDPF_XDP_RX_HASH	GENMASK_ULL(31, 0)
>   
>   	aligned_u64		qw3;
> +#define IDPF_XDP_RX_TS_HIGH	GENMASK_ULL(63, 32)
>   } __aligned(4 * sizeof(u64));
>   static_assert(sizeof(struct idpf_xdp_rx_desc) ==
>   	      sizeof(struct virtchnl2_rx_flex_desc_adv_nic_3));
> @@ -128,6 +130,8 @@ static_assert(sizeof(struct idpf_xdp_rx_desc) ==
>   #define idpf_xdp_rx_buf(desc)	FIELD_GET(IDPF_XDP_RX_BUF, (desc)->qw1)
>   #define idpf_xdp_rx_eop(desc)	!!((desc)->qw1 & IDPF_XDP_RX_EOP)
>   #define idpf_xdp_rx_hash(desc)	FIELD_GET(IDPF_XDP_RX_HASH, (desc)->qw2)
> +#define idpf_xdp_rx_ts_low(desc)	FIELD_GET(IDPF_XDP_RX_TS_LOW, (desc)->qw1)
> +#define idpf_xdp_rx_ts_high(desc)	FIELD_GET(IDPF_XDP_RX_TS_HIGH, (desc)->qw3)
>   
>   static inline void
>   idpf_xdp_get_qw0(struct idpf_xdp_rx_desc *desc,
> @@ -149,6 +153,9 @@ idpf_xdp_get_qw1(struct idpf_xdp_rx_desc *desc,
>   	desc->qw1 = ((const typeof(desc))rxd)->qw1;
>   #else
>   	desc->qw1 = ((u64)le16_to_cpu(rxd->buf_id) << 32) |
> +		    ((u64)rxd->ts_low << 24) |
> +		    ((u64)rxd->fflags1 << 16) |
> +		    ((u64)rxd->status_err1 << 8) |
>   		    rxd->status_err0_qw1;
>   #endif
>   }
> @@ -166,6 +173,19 @@ idpf_xdp_get_qw2(struct idpf_xdp_rx_desc *desc,
>   #endif
>   }
>   
> +static inline void
> +idpf_xdp_get_qw3(struct idpf_xdp_rx_desc *desc,
> +		 const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
> +{
> +#ifdef __LIBETH_WORD_ACCESS
> +	desc->qw3 = ((const typeof(desc))rxd)->qw3;
> +#else
> +	desc->qw3 = ((u64)le32_to_cpu(rxd->ts_high) << 32) |
> +		    ((u64)le16_to_cpu(rxd->fmd6) << 16) |
> +		    le16_to_cpu(rxd->l2tag1);
> +#endif

It’s done elsewhere in the file, but I wonder why use the preprocessor 
and not plain C code, and let the linker(?) remove the unneeded branch?

> +}
> +
>   void idpf_xdp_set_features(const struct idpf_vport *vport);
>   
>   int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp);


Kind regards,

Paul

Re: [Intel-wired-lan] [PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[Mina Almasry]

On Sat, Jan 10, 2026 at 12:36 AM Paul Menzel <pmenzel@molgen.mpg.de> wrote:
>
> Dear Mina,
>
>
> Thank you for your patch. Some minor comments, should you resend.
>

Thanks, looks like I have reviews and this is on its way, but should I
resend I will fix the minor comments.

> Am 23.12.25 um 20:46 schrieb Mina Almasry via Intel-wired-lan:
> > From: YiFei Zhu <zhuyifei@google.com>
> >
> > The logic is similar to idpf_rx_hwtstamp, but the data is exported
> > as a BPF kfunc instead of appended to an skb to support grabbing
> > timestamps in xsk packets.
> >
> > A idpf_queue_has(PTP, rxq) condition is added to check the queue
> > supports PTP similar to idpf_rx_process_skb_fields.
> >
> > Tested using an xsk connection and checking xdp timestamps are
> > retreivable in received packets.
>
> retr*ie*vable
>
> It’d be great if you could share the commands.
>

I don't have easy repro to share in the commit message. The test
involves hacking up the xsk_rr Sami used for his busypolling patch to
enable xdp metadata and retrieve timestamps, or (what I did) actually
set up openonload with this patch and test onload can get the
timestamps. Let me see what I can do, but it's likely too much context
for someone unfamiliar to piece together.

-- 
Thanks,
Mina

Re: [Intel-wired-lan] [PATCH iwl-next v4] idpf: export RX hardware timestamping information to XDP

[Alexander Lobakin]

From: Paul Menzel <pmenzel@molgen.mpg.de>
Date: Sat, 10 Jan 2026 09:35:58 +0100

> Dear Mina,
> 
> 
> Thank you for your patch. Some minor comments, should you resend.

[...]

>> @@ -166,6 +173,19 @@ idpf_xdp_get_qw2(struct idpf_xdp_rx_desc *desc,
>>   #endif
>>   }
>>   +static inline void
>> +idpf_xdp_get_qw3(struct idpf_xdp_rx_desc *desc,
>> +         const struct virtchnl2_rx_flex_desc_adv_nic_3 *rxd)
>> +{
>> +#ifdef __LIBETH_WORD_ACCESS
>> +    desc->qw3 = ((const typeof(desc))rxd)->qw3;
>> +#else
>> +    desc->qw3 = ((u64)le32_to_cpu(rxd->ts_high) << 32) |
>> +            ((u64)le16_to_cpu(rxd->fmd6) << 16) |
>> +            le16_to_cpu(rxd->l2tag1);
>> +#endif
> 
> It’s done elsewhere in the file, but I wonder why use the preprocessor
> and not plain C code, and let the linker(?) remove the unneeded branch?

Do you mean IS_ENABLED()?
In the libeth_xdp code, several paths won't build with IS_ENABLED(),
here in idpf it might work out, but I did it the same way as in
libeth_xdp for consistency.

> 
>> +}
>> +
>>   void idpf_xdp_set_features(const struct idpf_vport *vport);
>>     int idpf_xdp(struct net_device *dev, struct netdev_bpf *xdp);
> 
> 
> Kind regards,
> 
> Paul

Thanks,
Olek