diff mbox series

[v4,net-next,2/9] i40e: respect metadata on XSK Rx to skb

Message ID 20211208140702.642741-3-alexandr.lobakin@intel.com
State Accepted
Delegated to: Anthony Nguyen
Headers show
Series net: intel: napi_alloc_skb() vs metadata | expand

Commit Message

Alexander Lobakin Dec. 8, 2021, 2:06 p.m. UTC
For now, if the XDP prog returns XDP_PASS on XSK, the metadata will
be lost as it doesn't get copied to the skb.
Copy it along with the frame headers. Account its size on skb
allocation, and when copying just treat it as a part of the frame
and do a pull after to "move" it to the "reserved" zone.
net_prefetch() xdp->data_meta and align the copy size to speed-up
memcpy() a little and better match i40e_costruct_skb().

Fixes: 0a714186d3c0 ("i40e: add AF_XDP zero-copy Rx support")
Suggested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Suggested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

Comments

Jesper Dangaard Brouer Dec. 9, 2021, 8:27 a.m. UTC | #1
On 08/12/2021 15.06, Alexander Lobakin wrote:
> For now, if the XDP prog returns XDP_PASS on XSK, the metadata will
> be lost as it doesn't get copied to the skb.

I have an urge to add a newline here, when reading this, as IMHO it is a 
paragraph with the problem statement.

> Copy it along with the frame headers. Account its size on skb
> allocation, and when copying just treat it as a part of the frame
> and do a pull after to "move" it to the "reserved" zone.

Also newline here, as next paragraph are some extra details, you felt a 
need to explain to the reader.

> net_prefetch() xdp->data_meta and align the copy size to speed-up
> memcpy() a little and better match i40e_costruct_skb().
                                      ^^^^^^xx^^^^^^^^^

You have a general misspelling of this function name in all of your 
commit messages.

--Jesper
Alexander Lobakin Dec. 9, 2021, 5:38 p.m. UTC | #2
From: Jesper Dangaard Brouer <jbrouer@redhat.com>
Date: Thu, 9 Dec 2021 09:27:37 +0100

> On 08/12/2021 15.06, Alexander Lobakin wrote:
> > For now, if the XDP prog returns XDP_PASS on XSK, the metadata will
> > be lost as it doesn't get copied to the skb.
> 
> I have an urge to add a newline here, when reading this, as IMHO it is a 
> paragraph with the problem statement.
> 
> > Copy it along with the frame headers. Account its size on skb
> > allocation, and when copying just treat it as a part of the frame
> > and do a pull after to "move" it to the "reserved" zone.
> 
> Also newline here, as next paragraph are some extra details, you felt a 
> need to explain to the reader.
> 
> > net_prefetch() xdp->data_meta and align the copy size to speed-up
> > memcpy() a little and better match i40e_costruct_skb().
>                                       ^^^^^^xx^^^^^^^^^
> 
> You have a general misspelling of this function name in all of your 
> commit messages.

Oh gosh, I thought I don't have attention deficit. Thanks, maybe
Tony will fix it for me or I could send a follow-up (or resend if
needed, I saw those were already applied to dev-queue).

> 
> --Jesper

Al
Tony Nguyen Dec. 9, 2021, 6:50 p.m. UTC | #3
On Thu, 2021-12-09 at 18:38 +0100, Alexander Lobakin wrote:
> From: Jesper Dangaard Brouer <jbrouer@redhat.com>
> Date: Thu, 9 Dec 2021 09:27:37 +0100
> 
> > On 08/12/2021 15.06, Alexander Lobakin wrote:
> > > For now, if the XDP prog returns XDP_PASS on XSK, the metadata
> > > will
> > > be lost as it doesn't get copied to the skb.
> > 
> > I have an urge to add a newline here, when reading this, as IMHO it
> > is a 
> > paragraph with the problem statement.
> > 
> > > Copy it along with the frame headers. Account its size on skb
> > > allocation, and when copying just treat it as a part of the frame
> > > and do a pull after to "move" it to the "reserved" zone.
> > 
> > Also newline here, as next paragraph are some extra details, you
> > felt a 
> > need to explain to the reader.
> > 
> > > net_prefetch() xdp->data_meta and align the copy size to speed-up
> > > memcpy() a little and better match i40e_costruct_skb().
> >                                       ^^^^^^xx^^^^^^^^^
> > 
> > commit messages.
> 
> Oh gosh, I thought I don't have attention deficit. Thanks, maybe
> Tony will fix it for me or I could send a follow-up (or resend if
> needed, I saw those were already applied to dev-queue).

If there's no need for follow-ups beyond this change, I'll fix it up.

Thanks,
Tony

> > --Jesper
> 
> Al
Alexander Lobakin Dec. 10, 2021, 11:08 a.m. UTC | #4
From: Tony Nguyen <anthony.l.nguyen@intel.com>
Date: Thu, 9 Dec 2021 18:50:07 +0000

> On Thu, 2021-12-09 at 18:38 +0100, Alexander Lobakin wrote:
> > From: Jesper Dangaard Brouer <jbrouer@redhat.com>
> > Date: Thu, 9 Dec 2021 09:27:37 +0100
> > 
> > > On 08/12/2021 15.06, Alexander Lobakin wrote:
> > > > For now, if the XDP prog returns XDP_PASS on XSK, the metadata
> > > > will
> > > > be lost as it doesn't get copied to the skb.
> > > 
> > > I have an urge to add a newline here, when reading this, as IMHO it
> > > is a 
> > > paragraph with the problem statement.
> > > 
> > > > Copy it along with the frame headers. Account its size on skb
> > > > allocation, and when copying just treat it as a part of the frame
> > > > and do a pull after to "move" it to the "reserved" zone.
> > > 
> > > Also newline here, as next paragraph are some extra details, you
> > > felt a 
> > > need to explain to the reader.
> > > 
> > > > net_prefetch() xdp->data_meta and align the copy size to speed-up
> > > > memcpy() a little and better match i40e_costruct_skb().
> > >                                       ^^^^^^xx^^^^^^^^^
> > > 
> > > commit messages.
> > 
> > Oh gosh, I thought I don't have attention deficit. Thanks, maybe
> > Tony will fix it for me or I could send a follow-up (or resend if
> > needed, I saw those were already applied to dev-queue).
> 
> If there's no need for follow-ups beyond this change, I'll fix it up.

The rest is fine, thank you!

> Thanks,
> Tony
> 
> > > --Jesper
> > 
> > Al

Al
Bhandare, KiranX Jan. 10, 2022, 11:24 a.m. UTC | #5
> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Lobakin, Alexandr
> Sent: Wednesday, December 8, 2021 7:37 PM
> To: intel-wired-lan@lists.osuosl.org
> Cc: Song Liu <songliubraving@fb.com>; Alexei Starovoitov <ast@kernel.org>;
> Andrii Nakryiko <andrii@kernel.org>; Daniel Borkmann
> <daniel@iogearbox.net>; John Fastabend <john.fastabend@gmail.com>;
> Brouer, Jesper <brouer@redhat.com>; Yonghong Song <yhs@fb.com>;
> Jesper Dangaard Brouer <hawk@kernel.org>; KP Singh
> <kpsingh@kernel.org>; Jakub Kicinski <kuba@kernel.org>;
> netdev@vger.kernel.org; linux-kernel@vger.kernel.org; David S. Miller
> <davem@davemloft.net>; Björn Töpel <bjorn@kernel.org>;
> bpf@vger.kernel.org; Martin KaFai Lau <kafai@fb.com>
> Subject: [Intel-wired-lan] [PATCH v4 net-next 2/9] i40e: respect metadata on
> XSK Rx to skb
> 
> For now, if the XDP prog returns XDP_PASS on XSK, the metadata will be lost
> as it doesn't get copied to the skb.
> Copy it along with the frame headers. Account its size on skb allocation, and
> when copying just treat it as a part of the frame and do a pull after to "move"
> it to the "reserved" zone.
> net_prefetch() xdp->data_meta and align the copy size to speed-up
> memcpy() a little and better match i40e_costruct_skb().
> 
> Fixes: 0a714186d3c0 ("i40e: add AF_XDP zero-copy Rx support")
> Suggested-by: Jesper Dangaard Brouer <brouer@redhat.com>
> Suggested-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
> Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com>
> Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_xsk.c | 14 ++++++++++----
>  1 file changed, 10 insertions(+), 4 deletions(-)
> 

Tested-by: Kiran Bhandare <kiranx.bhandare@intel.com>  A Contingent Worker at Intel
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 9564906b7da8..0e8cf275e084 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -240,19 +240,25 @@  bool i40e_alloc_rx_buffers_zc(struct i40e_ring *rx_ring, u16 count)
 static struct sk_buff *i40e_construct_skb_zc(struct i40e_ring *rx_ring,
 					     struct xdp_buff *xdp)
 {
+	unsigned int totalsize = xdp->data_end - xdp->data_meta;
 	unsigned int metasize = xdp->data - xdp->data_meta;
-	unsigned int datasize = xdp->data_end - xdp->data;
 	struct sk_buff *skb;
 
+	net_prefetch(xdp->data_meta);
+
 	/* allocate a skb to store the frags */
-	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, datasize,
+	skb = __napi_alloc_skb(&rx_ring->q_vector->napi, totalsize,
 			       GFP_ATOMIC | __GFP_NOWARN);
 	if (unlikely(!skb))
 		goto out;
 
-	memcpy(__skb_put(skb, datasize), xdp->data, datasize);
-	if (metasize)
+	memcpy(__skb_put(skb, totalsize), xdp->data_meta,
+	       ALIGN(totalsize, sizeof(long)));
+
+	if (metasize) {
 		skb_metadata_set(skb, metasize);
+		__skb_pull(skb, metasize);
+	}
 
 out:
 	xsk_buff_free(xdp);