From: Olivier MATZ <olivier.matz@6wind.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>,
dev@dpdk.org, yuanhan.liu@linux.intel.com
Cc: konstantin.ananyev@intel.com, sugesh.chandran@intel.com,
bruce.richardson@intel.com, jianfeng.tan@intel.com,
helin.zhang@intel.com, adrien.mazarguil@6wind.com,
stephen@networkplumber.org, dprovan@bivio.net,
xiao.w.wang@intel.com
Subject: Re: [dpdk-dev] [PATCH v2 09/12] virtio: add Rx checksum offload support
Date: Tue, 11 Oct 2016 16:49:57 +0200 [thread overview]
Message-ID: <57FCFC15.6090305@6wind.com> (raw)
In-Reply-To: <65d18f11-9a51-a9d8-a649-6285fcdd0b2b@redhat.com>
On 10/11/2016 04:36 PM, Maxime Coquelin wrote:
>
>
> On 10/11/2016 04:29 PM, Olivier MATZ wrote:
>>
>>
>> On 10/11/2016 04:04 PM, Maxime Coquelin wrote:
>>>> +/* Optionally fill offload information in structure */
>>>> +static int
>>>> +virtio_rx_offload(struct rte_mbuf *m, struct virtio_net_hdr *hdr)
>>>> +{
>>>> + struct rte_net_hdr_lens hdr_lens;
>>>> + uint32_t hdrlen, ptype;
>>>> + int l4_supported = 0;
>>>> +
>>>> + /* nothing to do */
>>>> + if (hdr->flags == 0 && hdr->gso_type == VIRTIO_NET_HDR_GSO_NONE)
>>>> + return 0;
>>>> +
>>>> + m->ol_flags |= PKT_RX_IP_CKSUM_UNKNOWN;
>>>> +
>>>> + ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
>>>> + m->packet_type = ptype;
>>>> + if ((ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_TCP ||
>>>> + (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_UDP ||
>>>> + (ptype & RTE_PTYPE_L4_MASK) == RTE_PTYPE_L4_SCTP)
>>>> + l4_supported = 1;
>>>> +
>>>> + if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
>>>> + hdrlen = hdr_lens.l2_len + hdr_lens.l3_len + hdr_lens.l4_len;
>>>> + if (hdr->csum_start <= hdrlen && l4_supported) {
>>>> + m->ol_flags |= PKT_RX_L4_CKSUM_NONE;
>>>> + } else {
>>>> + /* Unknown proto or tunnel, do sw cksum. We can assume
>>>> + * the cksum field is in the first segment since the
>>>> + * buffers we provided to the host are large enough.
>>>> + * In case of SCTP, this will be wrong since it's a CRC
>>>> + * but there's nothing we can do.
>>>> + */
>>>> + uint16_t csum, off;
>>>> +
>>>> + csum = rte_raw_cksum_mbuf(m, hdr->csum_start,
>>>> + rte_pktmbuf_pkt_len(m) - hdr->csum_start);
>>>> + if (csum != 0xffff)
>>> Why don't we do the 1-complement if 0xffff?
>>
>> This was modified after a comment from Xiao.
>>
>> In checksum arithmetic (ones' complement), there are 2 equivalent ways
>> to say the checksum is 0: 0xffff (0-), and 0x0000 (0+).
>> Some protocols like UDP use this to differentiate between 0xffff (packet
>> checksum is 0) and 0x0000 (packet checksum is not calculated).
>>
>> Here, we want to avoid to set a checksum to 0, in case it would mean no
>> checksum for UDP packets. Instead, it is set to 0xffff, which is also a
>> valid checksum for this packet.
>
> Ha ok, I wasn't aware of this.
> Thanks for the explanation!
>
> Maybe not a big deal, but we could add likely around the test?
Yep, good idea.
Thanks!
Olivier
next prev parent reply other threads:[~2016-10-11 14:50 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-21 8:08 [dpdk-dev] [PATCH 00/12] net/virtio: add " Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 01/12] virtio: move device initialization in a function Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 02/12] virtio: setup and start cq in configure callback Olivier Matz
2016-07-21 21:15 ` Stephen Hemminger
2016-07-22 7:54 ` Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 03/12] virtio: reinitialize the device " Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 04/12] mbuf: add function to calculate a checksum Olivier Matz
2016-07-21 10:51 ` Ananyev, Konstantin
2016-07-21 16:26 ` Don Provan
2016-07-21 16:46 ` Olivier Matz
2016-07-22 8:24 ` Olivier Matz
2016-08-29 14:52 ` Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 05/12] mbuf: add new Rx checksum mbuf flags Olivier Matz
2016-07-21 21:22 ` Stephen Hemminger
2016-07-22 8:03 ` Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 06/12] app/testpmd: fix checksum stats in csum engine Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 07/12] mbuf: new flag for LRO Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 08/12] app/testpmd: display lro segment size Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 09/12] virtio: add Rx checksum offload support Olivier Matz
2016-07-27 9:52 ` Wang, Xiao W
2016-07-21 8:08 ` [dpdk-dev] [PATCH 10/12] virtio: add Tx " Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 11/12] virtio: add Lro support Olivier Matz
2016-07-21 8:08 ` [dpdk-dev] [PATCH 12/12] virtio: add Tso support Olivier Matz
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 00/12] net/virtio: add offload support Olivier Matz
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 01/12] virtio: move device initialization in a function Olivier Matz
2016-10-11 12:30 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 02/12] virtio: setup and start cq in configure callback Olivier Matz
2016-10-11 12:47 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 03/12] virtio: reinitialize the device " Olivier Matz
2016-10-11 13:13 ` Maxime Coquelin
2016-10-12 14:41 ` Yuanhan Liu
2016-10-12 16:01 ` Olivier MATZ
2016-10-13 7:54 ` Yuanhan Liu
2016-10-13 13:57 ` Olivier MATZ
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 04/12] net: add function to calculate a checksum in a mbuf Olivier Matz
2016-10-11 13:25 ` Maxime Coquelin
2016-10-11 13:33 ` Olivier MATZ
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 05/12] mbuf: add new Rx checksum mbuf flags Olivier Matz
2016-10-11 13:43 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 06/12] app/testpmd: fix checksum stats in csum engine Olivier Matz
2016-10-11 13:46 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 07/12] mbuf: new flag for LRO Olivier Matz
2016-10-11 13:48 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 08/12] app/testpmd: display lro segment size Olivier Matz
2016-10-11 13:49 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 09/12] virtio: add Rx checksum offload support Olivier Matz
2016-10-03 12:51 ` Maxime Coquelin
2016-10-05 11:56 ` Olivier Matz
2016-10-05 13:27 ` Maxime Coquelin
2016-10-05 13:30 ` Olivier Matz
2016-10-12 13:02 ` Yuanhan Liu
2016-10-12 15:55 ` Olivier MATZ
2016-10-11 14:04 ` Maxime Coquelin
2016-10-11 14:29 ` Olivier MATZ
2016-10-11 14:36 ` Maxime Coquelin
2016-10-11 14:49 ` Olivier MATZ [this message]
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 10/12] virtio: add Tx " Olivier Matz
2016-10-07 7:25 ` Maxime Coquelin
2016-10-07 16:36 ` Olivier Matz
2016-10-13 8:38 ` Yuanhan Liu
2016-10-13 13:58 ` Olivier MATZ
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 11/12] virtio: add Lro support Olivier Matz
2016-10-11 14:21 ` Maxime Coquelin
2016-10-03 9:00 ` [dpdk-dev] [PATCH v2 12/12] virtio: add Tso support Olivier Matz
2016-10-13 8:18 ` Yuanhan Liu
2016-10-13 14:02 ` Olivier MATZ
2016-10-13 14:16 ` Yuanhan Liu
2016-10-13 14:52 ` Olivier MATZ
2016-10-13 15:01 ` Yuanhan Liu
2016-10-13 15:15 ` Olivier MATZ
2016-10-13 15:29 ` Yuanhan Liu
2016-10-13 15:45 ` Olivier Matz
2016-10-13 16:01 ` Yuanhan Liu
2016-10-13 15:04 ` Yuanhan Liu
2016-10-13 23:33 ` Stephen Hemminger
2016-10-18 14:07 ` Olivier Matz
2016-10-11 11:35 ` [dpdk-dev] [PATCH v2 00/12] net/virtio: add offload support Yuanhan Liu
2016-10-11 12:14 ` Olivier MATZ
2016-10-11 15:37 ` Yuanhan Liu
2016-10-13 14:15 ` [dpdk-dev] [PATCH v3 " Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 01/12] net/virtio: move device initialization in a function Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 02/12] net/virtio: setup and start cq in configure callback Olivier Matz
2016-11-02 1:38 ` Yao, Lei A
2016-11-08 14:58 ` Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 03/12] net/virtio: reinitialize the device " Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 04/12] net: add function to calculate a checksum in a mbuf Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 05/12] mbuf: add new Rx checksum mbuf flags Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 06/12] app/testpmd: adapt checksum stats in csum engine Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 07/12] mbuf: new flag for LRO Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 08/12] app/testpmd: display lro segment size Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 09/12] net/virtio: add Rx checksum offload support Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 10/12] net/virtio: add Tx " Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 11/12] net/virtio: add Lro support Olivier Matz
2016-10-13 14:16 ` [dpdk-dev] [PATCH v3 12/12] net/virtio: add Tso support Olivier Matz
2016-10-13 16:05 ` Yuanhan Liu
2016-10-13 18:50 ` Thomas Monjalon
2016-10-13 19:58 ` Olivier Matz
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=57FCFC15.6090305@6wind.com \
--to=olivier.matz@6wind.com \
--cc=adrien.mazarguil@6wind.com \
--cc=bruce.richardson@intel.com \
--cc=dev@dpdk.org \
--cc=dprovan@bivio.net \
--cc=helin.zhang@intel.com \
--cc=jianfeng.tan@intel.com \
--cc=konstantin.ananyev@intel.com \
--cc=maxime.coquelin@redhat.com \
--cc=stephen@networkplumber.org \
--cc=sugesh.chandran@intel.com \
--cc=xiao.w.wang@intel.com \
--cc=yuanhan.liu@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).