Re: [PATCH net-next v2 12/14] octeontx2-pf: ipsec: Process CPT metapackets

[Simon Horman <horms@xxxxxxxxxx>]

On Wed, Jun 18, 2025 at 05:00:06PM +0530, Tanmay Jagdale wrote:
> CPT hardware forwards decrypted IPsec packets to NIX via the X2P bus
> as metapackets which are of 256 bytes in length. Each metapacket
> contains CPT_PARSE_HDR_S and initial bytes of the decrypted packet
> that helps NIX RX in classifying and submitting to CPU. Additionally,
> CPT also sets BIT(11) of the channel number to indicate that it's a
> 2nd pass packet from CPT.
> 
> Since the metapackets are not complete packets, they don't have to go
> through L3/L4 layer length and checksum verification so these are
> disabled via the NIX_LF_INLINE_RQ_CFG mailbox during IPsec initialization.
> 
> The CPT_PARSE_HDR_S contains a WQE pointer to the complete decrypted
> packet. Add code in the rx NAPI handler to parse the header and extract
> WQE pointer. Later, use this WQE pointer to construct the skb, set the
> XFRM packet mode flags to indicate successful decryption before submitting
> it to the network stack.
> 
> Signed-off-by: Tanmay Jagdale <tanmay@xxxxxxxxxxx>
> ---
> Changes in V2:
> - Removed unnecessary casts
> - Don't convert complete cpt_parse_hdr from BE to LE and just
>   convert required fields
> - Fixed logic to avoid repeated calculation for start and end in sg
> 
> V1 Link: https://lore.kernel.org/netdev/20250502132005.611698-15-tanmay@xxxxxxxxxxx/
> 
>  .../marvell/octeontx2/nic/cn10k_ipsec.c       | 52 +++++++++++++++++++
>  .../marvell/octeontx2/nic/cn10k_ipsec.h       | 48 +++++++++++++++++
>  .../marvell/octeontx2/nic/otx2_common.h       |  2 +
>  .../marvell/octeontx2/nic/otx2_struct.h       | 16 ++++++
>  .../marvell/octeontx2/nic/otx2_txrx.c         | 29 +++++++++--
>  5 files changed, 144 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_ipsec.c b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_ipsec.c
> index 5cb6bc835e56..a95878378334 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_ipsec.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_ipsec.c
> @@ -346,6 +346,58 @@ static int cn10k_outb_cpt_init(struct net_device *netdev)
>  	return ret;
>  }
>  
> +struct nix_wqe_rx_s *cn10k_ipsec_process_cpt_metapkt(struct otx2_nic *pfvf,
> +						     struct nix_cqe_rx_s *cqe,
> +						     struct sk_buff *skb,
> +						     int qidx)
> +{
> +	struct nix_rx_sg_s *sg = &cqe->sg;
> +	struct nix_wqe_rx_s *wqe = NULL;
> +	u64 *seg_addr = &sg->seg_addr;
> +	struct cpt_parse_hdr_s *cptp;
> +	struct xfrm_offload *xo;
> +	struct xfrm_state *xs;
> +	struct sec_path *sp;
> +	void *va;
> +
> +	/* CPT_PARSE_HDR_S is present in the beginning of the buffer */
> +	va = phys_to_virt(otx2_iova_to_phys(pfvf->iommu_domain, *seg_addr));
> +
> +	cptp = (struct cpt_parse_hdr_s *)va;
> +
> +	/* Convert the wqe_ptr from CPT_PARSE_HDR_S to a CPU usable pointer */
> +	wqe = phys_to_virt(otx2_iova_to_phys(pfvf->iommu_domain,
> +					     be64_to_cpu(cptp->wqe_ptr)));

Hi Tanmay,

be64_to_cpu expects a __be64 argument, but the type of cptp->wqe_ptr is u64.
Or, IOW, be64_to_cpu expects to be based a big endian value but
the type of it's argument is host byte order.

> +
> +	/* Get the XFRM state pointer stored in SA context */
> +	xs = pfvf->ipsec.inb_sa->base +
> +	     (be32_to_cpu(cptp->cookie) * pfvf->ipsec.sa_tbl_entry_sz) + 1024;

Likewise with cookie here.

:Flagged by Sparse.

...

> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_ipsec.h b/drivers/net/ethernet/marvell/octeontx2/nic/cn10k_ipsec.h

...

> @@ -302,6 +303,41 @@ struct cpt_sg_s {
>  	u64 rsvd_63_50	: 14;
>  };
>  
> +/* CPT Parse Header Structure for Inbound packets */
> +struct cpt_parse_hdr_s {
> +	/* Word 0 */
> +	u64 cookie      : 32;
> +	u64 match_id    : 16;
> +	u64 err_sum     : 1;
> +	u64 reas_sts    : 4;
> +	u64 reserved_53 : 1;
> +	u64 et_owr      : 1;
> +	u64 pkt_fmt     : 1;
> +	u64 pad_len     : 3;
> +	u64 num_frags   : 3;
> +	u64 pkt_out     : 2;
> +
> +	/* Word 1 */
> +	u64 wqe_ptr;
> +
> +	/* Word 2 */
> +	u64 frag_age    : 16;
> +	u64 res_32_16   : 16;
> +	u64 pf_func     : 16;
> +	u64 il3_off     : 8;
> +	u64 fi_pad      : 3;
> +	u64 fi_offset   : 5;
> +
> +	/* Word 3 */
> +	u64 hw_ccode    : 8;
> +	u64 uc_ccode    : 8;
> +	u64 res3_32_16  : 16;
> +	u64 spi         : 32;
> +
> +	/* Word 4 */
> +	u64 misc;
> +};
> +
>  /* CPT LF_INPROG Register */
>  #define CPT_LF_INPROG_INFLIGHT	GENMASK_ULL(8, 0)
>  #define CPT_LF_INPROG_GRB_CNT	GENMASK_ULL(39, 32)

...