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.

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

Cc: intel-wired-lan@lists.osuosl.org

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Mina Almasry <almasrymina@google.com>
---
 drivers/net/ethernet/intel/idpf/xdp.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/net/ethernet/intel/idpf/xdp.c b/drivers/net/ethernet/intel/idpf/xdp.c
index 21ce25b0567f..850389ca66b6 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"
@@ -369,6 +370,31 @@ int idpf_xdp_xmit(struct net_device *dev, int n, struct xdp_frame **frames,
 				       idpf_xdp_tx_finalize);
 }
 
+static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
+{
+	const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
+	const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
+	const struct idpf_rx_queue *rxq;
+	u64 cached_time, ts_ns;
+	u32 ts_high;
+
+	rx_desc = xdp->desc;
+	rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
+
+	if (!idpf_queue_has(PTP, rxq))
+		return -ENODATA;
+	if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
+		return -ENODATA;
+
+	cached_time = READ_ONCE(rxq->cached_phc_time);
+
+	ts_high = le32_to_cpu(rx_desc->ts_high);
+	ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time, ts_high);
+
+	*timestamp = ts_ns;
+	return 0;
+}
+
 static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
 			      enum xdp_rss_hash_type *rss_type)
 {
@@ -392,6 +418,7 @@ static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
 }
 
 static const struct xdp_metadata_ops idpf_xdpmo = {
+	.xmo_rx_timestamp	= idpf_xdpmo_rx_timestamp,
 	.xmo_rx_hash		= idpf_xdpmo_rx_hash,
 };
 

base-commit: e05021a829b834fecbd42b173e55382416571b2c
-- 
2.52.0.rc2.455.g230fcf2819-goog

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Mina Almasry
> Sent: Saturday, November 22, 2025 3:09 PM
> To: netdev@vger.kernel.org; bpf@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Cc: YiFei Zhu <zhuyifei@google.com>; Alexei Starovoitov
> <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S.
> Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Jesper
> Dangaard Brouer <hawk@kernel.org>; John Fastabend
> <john.fastabend@gmail.com>; Stanislav Fomichev <sdf@fomichev.me>;
> Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw
> <przemyslaw.kitszel@intel.com>; Andrew Lunn <andrew+netdev@lunn.ch>;
> Eric Dumazet <edumazet@google.com>; Paolo Abeni <pabeni@redhat.com>;
> Lobakin, Aleksander <aleksander.lobakin@intel.com>; Richard Cochran
> <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org; Mina
> Almasry <almasrymina@google.com>
> Subject: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> hardware timestamping information to XDP
> 
> 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.
> 
> A idpf_queue_has(PTP, rxq) condition is added to check the queue
> supports PTP similar to idpf_rx_process_skb_fields.
> 
> Cc: intel-wired-lan@lists.osuosl.org
> 
> Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> Signed-off-by: Mina Almasry <almasrymina@google.com>
> ---
>  drivers/net/ethernet/intel/idpf/xdp.c | 27
> +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/xdp.c
> b/drivers/net/ethernet/intel/idpf/xdp.c
> index 21ce25b0567f..850389ca66b6 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"
> @@ -369,6 +370,31 @@ int idpf_xdp_xmit(struct net_device *dev, int n,
> struct xdp_frame **frames,
>  				       idpf_xdp_tx_finalize);
>  }
> 
> +static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64
> +*timestamp) {
> +	const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
> +	const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
> +	const struct idpf_rx_queue *rxq;
> +	u64 cached_time, ts_ns;
> +	u32 ts_high;
> +
> +	rx_desc = xdp->desc;
> +	rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
> +
> +	if (!idpf_queue_has(PTP, rxq))
> +		return -ENODATA;
> +	if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
> +		return -ENODATA;
RX flex desc fields are little‑endian.
You already convert ts_high with le32_to_cpu(), but test ts_low directly against the mask.
On big‑endian this can misdetect the bit and spuriously return -ENODATA.
Please convert ts_low to host order before the bit test.
See existing IDPF/ICE patterns where descriptor words are leXX_to_cpu()‑converted prior to FIELD_GET() / bit checks.
Also, per the XDP RX metadata kfunc docs, -ENODATA must reflect true absence of per‑packet metadata; endianness‑correct testing is required to uphold the semantic.

> +
> +	cached_time = READ_ONCE(rxq->cached_phc_time);
> +
> +	ts_high = le32_to_cpu(rx_desc->ts_high);
> +	ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time,
> ts_high);
> +
> +	*timestamp = ts_ns;
> +	return 0;
> +}
> +
>  static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
>  			      enum xdp_rss_hash_type *rss_type)  { @@ -
> 392,6 +418,7 @@ static int idpf_xdpmo_rx_hash(const struct xdp_md
> *ctx, u32 *hash,  }
> 
>  static const struct xdp_metadata_ops idpf_xdpmo = {
> +	.xmo_rx_timestamp	= idpf_xdpmo_rx_timestamp,
>  	.xmo_rx_hash		= idpf_xdpmo_rx_hash,
>  };
> 
> 
> base-commit: e05021a829b834fecbd42b173e55382416571b2c
> --
> 2.52.0.rc2.455.g230fcf2819-goog

On Mon, Nov 24, 2025 at 2:33 AM Loktionov, Aleksandr
<aleksandr.loktionov@intel.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> > Of Mina Almasry
> > Sent: Saturday, November 22, 2025 3:09 PM
> > To: netdev@vger.kernel.org; bpf@vger.kernel.org; linux-
> > kernel@vger.kernel.org
> > Cc: YiFei Zhu <zhuyifei@google.com>; Alexei Starovoitov
> > <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S.
> > Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Jesper
> > Dangaard Brouer <hawk@kernel.org>; John Fastabend
> > <john.fastabend@gmail.com>; Stanislav Fomichev <sdf@fomichev.me>;
> > Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw
> > <przemyslaw.kitszel@intel.com>; Andrew Lunn <andrew+netdev@lunn.ch>;
> > Eric Dumazet <edumazet@google.com>; Paolo Abeni <pabeni@redhat.com>;
> > Lobakin, Aleksander <aleksander.lobakin@intel.com>; Richard Cochran
> > <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org; Mina
> > Almasry <almasrymina@google.com>
> > Subject: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> > hardware timestamping information to XDP
> >
> > 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.
> >
> > A idpf_queue_has(PTP, rxq) condition is added to check the queue
> > supports PTP similar to idpf_rx_process_skb_fields.
> >
> > Cc: intel-wired-lan@lists.osuosl.org
> >
> > Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> > Signed-off-by: Mina Almasry <almasrymina@google.com>
> > ---
> >  drivers/net/ethernet/intel/idpf/xdp.c | 27
> > +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/intel/idpf/xdp.c
> > b/drivers/net/ethernet/intel/idpf/xdp.c
> > index 21ce25b0567f..850389ca66b6 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"
> > @@ -369,6 +370,31 @@ int idpf_xdp_xmit(struct net_device *dev, int n,
> > struct xdp_frame **frames,
> >                                      idpf_xdp_tx_finalize);
> >  }
> >
> > +static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64
> > +*timestamp) {
> > +     const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
> > +     const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
> > +     const struct idpf_rx_queue *rxq;
> > +     u64 cached_time, ts_ns;
> > +     u32 ts_high;
> > +
> > +     rx_desc = xdp->desc;
> > +     rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
> > +
> > +     if (!idpf_queue_has(PTP, rxq))
> > +             return -ENODATA;
> > +     if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
> > +             return -ENODATA;
> RX flex desc fields are little‑endian.
> You already convert ts_high with le32_to_cpu(), but test ts_low directly against the mask.
> On big‑endian this can misdetect the bit and spuriously return -ENODATA.
> Please convert ts_low to host order before the bit test.
> See existing IDPF/ICE patterns where descriptor words are leXX_to_cpu()‑converted prior to FIELD_GET() / bit checks.
> Also, per the XDP RX metadata kfunc docs, -ENODATA must reflect true absence of per‑packet metadata; endianness‑correct testing is required to uphold the semantic.
>

Hey, sorry for the late reply. Initially when I read the reply, I
thought: "why not, lets add a leXX_to_cpu".

But now that I look closer to implement the change and submit v2, it
looks correct as written. ts_low is defined as a u8:

```
struct virtchnl2_rx_flex_desc_adv_nic_3 {
...
u8 ts_low;
```

So it should not be fed into any leXX_to_cpu() functions, no?

I also looked at other u8 members in this struct like `u8
status_err0_qw0` and `u8 status_err0_qw1`, and both are used in
existing code without a conversion. So it seems correct as written.
Can you reconsdirer?

If you insist some change is required, can you elaborate more on what
needs to be changed? There is no le8_to_cpu, unless a trivial one that
does nothing (one byte struct cannot be little or big endian).

> -----Original Message-----
> From: Mina Almasry <almasrymina@google.com>
> Sent: Monday, December 1, 2025 2:27 AM
> To: Loktionov, Aleksandr <aleksandr.loktionov@intel.com>
> Cc: netdev@vger.kernel.org; bpf@vger.kernel.org; linux-
> kernel@vger.kernel.org; YiFei Zhu <zhuyifei@google.com>; Alexei
> Starovoitov <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>;
> David S. Miller <davem@davemloft.net>; Jakub Kicinski
> <kuba@kernel.org>; Jesper Dangaard Brouer <hawk@kernel.org>; John
> Fastabend <john.fastabend@gmail.com>; Stanislav Fomichev
> <sdf@fomichev.me>; Nguyen, Anthony L <anthony.l.nguyen@intel.com>;
> Kitszel, Przemyslaw <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>; Eric Dumazet <edumazet@google.com>; Paolo
> Abeni <pabeni@redhat.com>; Lobakin, Aleksander
> <aleksander.lobakin@intel.com>; Richard Cochran
> <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org
> Subject: Re: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> hardware timestamping information to XDP
> 
> On Mon, Nov 24, 2025 at 2:33 AM Loktionov, Aleksandr
> <aleksandr.loktionov@intel.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On
> Behalf
> > > Of Mina Almasry
> > > Sent: Saturday, November 22, 2025 3:09 PM
> > > To: netdev@vger.kernel.org; bpf@vger.kernel.org; linux-
> > > kernel@vger.kernel.org
> > > Cc: YiFei Zhu <zhuyifei@google.com>; Alexei Starovoitov
> > > <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S.
> > > Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>;
> > > Jesper Dangaard Brouer <hawk@kernel.org>; John Fastabend
> > > <john.fastabend@gmail.com>; Stanislav Fomichev <sdf@fomichev.me>;
> > > Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw
> > > <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>;
> > > Eric Dumazet <edumazet@google.com>; Paolo Abeni
> <pabeni@redhat.com>;
> > > Lobakin, Aleksander <aleksander.lobakin@intel.com>; Richard
> Cochran
> > > <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org; Mina
> > > Almasry <almasrymina@google.com>
> > > Subject: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> > > hardware timestamping information to XDP
> > >
> > > 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.
> > >
> > > A idpf_queue_has(PTP, rxq) condition is added to check the queue
> > > supports PTP similar to idpf_rx_process_skb_fields.
> > >
> > > Cc: intel-wired-lan@lists.osuosl.org
> > >
> > > Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> > > Signed-off-by: Mina Almasry <almasrymina@google.com>
> > > ---
> > >  drivers/net/ethernet/intel/idpf/xdp.c | 27
> > > +++++++++++++++++++++++++++
> > >  1 file changed, 27 insertions(+)
> > >
> > > diff --git a/drivers/net/ethernet/intel/idpf/xdp.c
> > > b/drivers/net/ethernet/intel/idpf/xdp.c
> > > index 21ce25b0567f..850389ca66b6 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"
> > > @@ -369,6 +370,31 @@ int idpf_xdp_xmit(struct net_device *dev, int
> > > n, struct xdp_frame **frames,
> > >                                      idpf_xdp_tx_finalize);  }
> > >
> > > +static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64
> > > +*timestamp) {
> > > +     const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
> > > +     const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
> > > +     const struct idpf_rx_queue *rxq;
> > > +     u64 cached_time, ts_ns;
> > > +     u32 ts_high;
> > > +
> > > +     rx_desc = xdp->desc;
> > > +     rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
> > > +
> > > +     if (!idpf_queue_has(PTP, rxq))
> > > +             return -ENODATA;
> > > +     if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
> > > +             return -ENODATA;
> > RX flex desc fields are little‑endian.
> > You already convert ts_high with le32_to_cpu(), but test ts_low
> directly against the mask.
> > On big‑endian this can misdetect the bit and spuriously return -
> ENODATA.
> > Please convert ts_low to host order before the bit test.
> > See existing IDPF/ICE patterns where descriptor words are
> leXX_to_cpu()‑converted prior to FIELD_GET() / bit checks.
> > Also, per the XDP RX metadata kfunc docs, -ENODATA must reflect true
> absence of per‑packet metadata; endianness‑correct testing is required
> to uphold the semantic.
> >
> 
> Hey, sorry for the late reply. Initially when I read the reply, I
> thought: "why not, lets add a leXX_to_cpu".
> 
> But now that I look closer to implement the change and submit v2, it
> looks correct as written. ts_low is defined as a u8:
> 
> ```
> struct virtchnl2_rx_flex_desc_adv_nic_3 { ...
> u8 ts_low;
> ```
> 
> So it should not be fed into any leXX_to_cpu() functions, no?
> 
> I also looked at other u8 members in this struct like `u8
> status_err0_qw0` and `u8 status_err0_qw1`, and both are used in
> existing code without a conversion. So it seems correct as written.
> Can you reconsdirer?
> 
Oh, yes. You are right. For u8 byte endianness has no sense. Sorry.

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>

On Mon, Nov 24, 2025 at 12:33 AM Loktionov, Aleksandr
<aleksandr.loktionov@intel.com> wrote:
>
>
>
> > -----Original Message-----
> > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> > Of Mina Almasry
> > Sent: Saturday, November 22, 2025 3:09 PM
> > To: netdev@vger.kernel.org; bpf@vger.kernel.org; linux-
> > kernel@vger.kernel.org
> > Cc: YiFei Zhu <zhuyifei@google.com>; Alexei Starovoitov
> > <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S.
> > Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Jesper
> > Dangaard Brouer <hawk@kernel.org>; John Fastabend
> > <john.fastabend@gmail.com>; Stanislav Fomichev <sdf@fomichev.me>;
> > Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw
> > <przemyslaw.kitszel@intel.com>; Andrew Lunn <andrew+netdev@lunn.ch>;
> > Eric Dumazet <edumazet@google.com>; Paolo Abeni <pabeni@redhat.com>;
> > Lobakin, Aleksander <aleksander.lobakin@intel.com>; Richard Cochran
> > <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org; Mina
> > Almasry <almasrymina@google.com>
> > Subject: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> > hardware timestamping information to XDP
> >
> > 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.
> >
> > A idpf_queue_has(PTP, rxq) condition is added to check the queue
> > supports PTP similar to idpf_rx_process_skb_fields.
> >
> > Cc: intel-wired-lan@lists.osuosl.org
> >
> > Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> > Signed-off-by: Mina Almasry <almasrymina@google.com>
> > ---
> >  drivers/net/ethernet/intel/idpf/xdp.c | 27
> > +++++++++++++++++++++++++++
> >  1 file changed, 27 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/intel/idpf/xdp.c
> > b/drivers/net/ethernet/intel/idpf/xdp.c
> > index 21ce25b0567f..850389ca66b6 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"
> > @@ -369,6 +370,31 @@ int idpf_xdp_xmit(struct net_device *dev, int n,
> > struct xdp_frame **frames,
> >                                      idpf_xdp_tx_finalize);
> >  }
> >
> > +static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64
> > +*timestamp) {
> > +     const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
> > +     const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
> > +     const struct idpf_rx_queue *rxq;
> > +     u64 cached_time, ts_ns;
> > +     u32 ts_high;
> > +
> > +     rx_desc = xdp->desc;
> > +     rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
> > +
> > +     if (!idpf_queue_has(PTP, rxq))
> > +             return -ENODATA;
> > +     if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
> > +             return -ENODATA;
> RX flex desc fields are little‑endian.
> You already convert ts_high with le32_to_cpu(), but test ts_low directly against the mask.
> On big‑endian this can misdetect the bit and spuriously return -ENODATA.
> Please convert ts_low to host order before the bit test.
> See existing IDPF/ICE patterns where descriptor words are leXX_to_cpu()‑converted prior to FIELD_GET() / bit checks.
> Also, per the XDP RX metadata kfunc docs, -ENODATA must reflect true absence of per‑packet metadata; endianness‑correct testing is required to uphold the semantic.

The logic is copied as verbatim from idpf_rx_hwtstamp:

static void
idpf_rx_hwtstamp(const struct idpf_rx_queue *rxq,
                 const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc,
                 struct sk_buff *skb)
{
        u64 cached_time, ts_ns;
        u32 ts_high;

        if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
                return;

        cached_time = READ_ONCE(rxq->cached_phc_time);

        ts_high = le32_to_cpu(rx_desc->ts_high);
        ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time, ts_high);
[...]

I assume that is incorrect and would need to be fixed too?

YiFei Zhu

> > +
> > +     cached_time = READ_ONCE(rxq->cached_phc_time);
> > +
> > +     ts_high = le32_to_cpu(rx_desc->ts_high);
> > +     ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time,
> > ts_high);
> > +
> > +     *timestamp = ts_ns;
> > +     return 0;
> > +}
> > +
> >  static int idpf_xdpmo_rx_hash(const struct xdp_md *ctx, u32 *hash,
> >                             enum xdp_rss_hash_type *rss_type)  { @@ -
> > 392,6 +418,7 @@ static int idpf_xdpmo_rx_hash(const struct xdp_md
> > *ctx, u32 *hash,  }
> >
> >  static const struct xdp_metadata_ops idpf_xdpmo = {
> > +     .xmo_rx_timestamp       = idpf_xdpmo_rx_timestamp,
> >       .xmo_rx_hash            = idpf_xdpmo_rx_hash,
> >  };
> >
> >
> > base-commit: e05021a829b834fecbd42b173e55382416571b2c
> > --
> > 2.52.0.rc2.455.g230fcf2819-goog
>

> -----Original Message-----
> From: YiFei Zhu <zhuyifei@google.com>
> Sent: Monday, November 24, 2025 11:52 AM
> To: Loktionov, Aleksandr <aleksandr.loktionov@intel.com>
> Cc: Mina Almasry <almasrymina@google.com>; netdev@vger.kernel.org;
> bpf@vger.kernel.org; linux-kernel@vger.kernel.org; Alexei Starovoitov
> <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S.
> Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Jesper
> Dangaard Brouer <hawk@kernel.org>; John Fastabend
> <john.fastabend@gmail.com>; Stanislav Fomichev <sdf@fomichev.me>;
> Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel, Przemyslaw
> <przemyslaw.kitszel@intel.com>; Andrew Lunn <andrew+netdev@lunn.ch>;
> Eric Dumazet <edumazet@google.com>; Paolo Abeni <pabeni@redhat.com>;
> Lobakin, Aleksander <aleksander.lobakin@intel.com>; Richard Cochran
> <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org
> Subject: Re: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> hardware timestamping information to XDP
> 
> On Mon, Nov 24, 2025 at 12:33 AM Loktionov, Aleksandr
> <aleksandr.loktionov@intel.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On
> Behalf
> > > Of Mina Almasry
> > > Sent: Saturday, November 22, 2025 3:09 PM
> > > To: netdev@vger.kernel.org; bpf@vger.kernel.org; linux-
> > > kernel@vger.kernel.org
> > > Cc: YiFei Zhu <zhuyifei@google.com>; Alexei Starovoitov
> > > <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S.
> > > Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>;
> > > Jesper Dangaard Brouer <hawk@kernel.org>; John Fastabend
> > > <john.fastabend@gmail.com>; Stanislav Fomichev <sdf@fomichev.me>;
> > > Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Kitszel,
> Przemyslaw
> > > <przemyslaw.kitszel@intel.com>; Andrew Lunn
> <andrew+netdev@lunn.ch>;
> > > Eric Dumazet <edumazet@google.com>; Paolo Abeni
> <pabeni@redhat.com>;
> > > Lobakin, Aleksander <aleksander.lobakin@intel.com>; Richard
> Cochran
> > > <richardcochran@gmail.com>; intel-wired-lan@lists.osuosl.org; Mina
> > > Almasry <almasrymina@google.com>
> > > Subject: [Intel-wired-lan] [PATCH net-next v1] idpf: export RX
> > > hardware timestamping information to XDP
> > >
> > > 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.
> > >
> > > A idpf_queue_has(PTP, rxq) condition is added to check the queue
> > > supports PTP similar to idpf_rx_process_skb_fields.
> > >
> > > Cc: intel-wired-lan@lists.osuosl.org
> > >
> > > Signed-off-by: YiFei Zhu <zhuyifei@google.com>
> > > Signed-off-by: Mina Almasry <almasrymina@google.com>
> > > ---
> > >  drivers/net/ethernet/intel/idpf/xdp.c | 27
> > > +++++++++++++++++++++++++++
> > >  1 file changed, 27 insertions(+)
> > >
> > > diff --git a/drivers/net/ethernet/intel/idpf/xdp.c
> > > b/drivers/net/ethernet/intel/idpf/xdp.c
> > > index 21ce25b0567f..850389ca66b6 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"
> > > @@ -369,6 +370,31 @@ int idpf_xdp_xmit(struct net_device *dev, int
> > > n, struct xdp_frame **frames,
> > >                                      idpf_xdp_tx_finalize);  }
> > >
> > > +static int idpf_xdpmo_rx_timestamp(const struct xdp_md *ctx, u64
> > > +*timestamp) {
> > > +     const struct virtchnl2_rx_flex_desc_adv_nic_3 *rx_desc;
> > > +     const struct libeth_xdp_buff *xdp = (typeof(xdp))ctx;
> > > +     const struct idpf_rx_queue *rxq;
> > > +     u64 cached_time, ts_ns;
> > > +     u32 ts_high;
> > > +
> > > +     rx_desc = xdp->desc;
> > > +     rxq = libeth_xdp_buff_to_rq(xdp, typeof(*rxq), xdp_rxq);
> > > +
> > > +     if (!idpf_queue_has(PTP, rxq))
> > > +             return -ENODATA;
> > > +     if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
> > > +             return -ENODATA;
> > RX flex desc fields are little‑endian.
> > You already convert ts_high with le32_to_cpu(), but test ts_low
> directly against the mask.
> > On big‑endian this can misdetect the bit and spuriously return -
> ENODATA.
> > Please convert ts_low to host order before the bit test.
> > See existing IDPF/ICE patterns where descriptor words are
> leXX_to_cpu()‑converted prior to FIELD_GET() / bit checks.
> > Also, per the XDP RX metadata kfunc docs, -ENODATA must reflect true
> absence of per‑packet metadata; endianness‑correct testing is required
> to uphold the semantic.
> 
> The logic is copied as verbatim from idpf_rx_hwtstamp:
> 
> static void
> idpf_rx_hwtstamp(const struct idpf_rx_queue *rxq,
>                  const struct virtchnl2_rx_flex_desc_adv_nic_3
> *rx_desc,
>                  struct sk_buff *skb)
> {
>         u64 cached_time, ts_ns;
>         u32 ts_high;
> 
>         if (!(rx_desc->ts_low & VIRTCHNL2_RX_FLEX_TSTAMP_VALID))
>                 return;
> 
>         cached_time = READ_ONCE(rxq->cached_phc_time);
> 
>         ts_high = le32_to_cpu(rx_desc->ts_high);
>         ts_ns = idpf_ptp_tstamp_extend_32b_to_64b(cached_time,
> ts_high); [...]
> 
> I assume that is incorrect and would need to be fixed too?
> 
I think must be fixed.

With the best regards
Alex

> YiFei Zhu


...