[dpdk-dev] Non-working TX IP checksum offload

[Angela Czubak <ACzubak@pl.ibm.com>]

Hi,

I have some difficulties using ip checksum tx offload capabilities - I 
think I set everything as advised by the API documentation, but 
unfortunately the packet leaves the interface with its ip checksum still 
being zero (it reaches its destination).

What I do is:
buffer->ol_flags |= PKT_TX_IP_CKSUM|PKT_TX_IPV4;
ip_header->hdr_checksum = 0;
buffer->l3_len = sizeof(struct ipv4_hdr);
buffer->l2_len = sizeof(struct ether_hdr);

In L4 there's UDP, which checksum is zeroed if that matters.

Is there something I am missing? The NIC is Intel Corporation Ethernet 
Controller X710 for 10GbE SFP+ (rev 01).

What is more, is there any particular reason for assuming in 
i40e_xmit_pkts that offloading checksums is unlikely (I mean the line no 
1307 "if (unlikely(ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK))" at 
dpdk-2.0.0/lib/librte_pmd_i40e/i40e_rxtx.c)?

Regards,
Angela
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From: Andriy Berestovskyy <aber@semihalf.com>
Date: Fri, 17 Jul 2015 16:37:45 +0200
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To: Angela Czubak <ACzubak@pl.ibm.com>
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Subject: Re: [dpdk-dev] Non-working TX IP checksum offload
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Cze=C5=9B=C4=87 Angela,
Make sure your NIC is configured properly as described in this thread:
http://dpdk.org/ml/archives/dev/2015-May/018096.html

Andriy

On Fri, Jul 17, 2015 at 4:23 PM, Angela Czubak <ACzubak@pl.ibm.com> wrote:
> Hi,
>
> I have some difficulties using ip checksum tx offload capabilities - I
> think I set everything as advised by the API documentation, but
> unfortunately the packet leaves the interface with its ip checksum still
> being zero (it reaches its destination).
>
> What I do is:
> buffer->ol_flags |=3D PKT_TX_IP_CKSUM|PKT_TX_IPV4;
> ip_header->hdr_checksum =3D 0;
> buffer->l3_len =3D sizeof(struct ipv4_hdr);
> buffer->l2_len =3D sizeof(struct ether_hdr);
>
> In L4 there's UDP, which checksum is zeroed if that matters.
>
> Is there something I am missing? The NIC is Intel Corporation Ethernet
> Controller X710 for 10GbE SFP+ (rev 01).
>
> What is more, is there any particular reason for assuming in
> i40e_xmit_pkts that offloading checksums is unlikely (I mean the line no
> 1307 "if (unlikely(ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK))" at
> dpdk-2.0.0/lib/librte_pmd_i40e/i40e_rxtx.c)?
>
> Regards,
> Angela



--=20
Andriy Berestovskyy