From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Olivier MATZ <olivier.matz@6wind.com>
Cc: dev@dpdk.org, 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 12/12] virtio: add Tso support
Date: Thu, 13 Oct 2016 22:16:54 +0800 [thread overview]
Message-ID: <20161013141654.GW16751@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <57FF9409.2090205@6wind.com>
On Thu, Oct 13, 2016 at 04:02:49PM +0200, Olivier MATZ wrote:
>
>
> On 10/13/2016 10:18 AM, Yuanhan Liu wrote:
> >On Mon, Oct 03, 2016 at 11:00:23AM +0200, Olivier Matz wrote:
> >>+/* When doing TSO, the IP length is not included in the pseudo header
> >>+ * checksum of the packet given to the PMD, but for virtio it is
> >>+ * expected.
> >>+ */
> >>+static void
> >>+virtio_tso_fix_cksum(struct rte_mbuf *m)
> >>+{
> >>+ /* common case: header is not fragmented */
> >>+ if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
> >>+ m->l4_len)) {
> >...
> >>+ /* replace it in the packet */
> >>+ th->cksum = new_cksum;
> >>+ } else {
> >...
> >>+ /* replace it in the packet */
> >>+ *rte_pktmbuf_mtod_offset(m, uint8_t *,
> >>+ m->l2_len + m->l3_len + 16) = new_cksum.u8[0];
> >>+ *rte_pktmbuf_mtod_offset(m, uint8_t *,
> >>+ m->l2_len + m->l3_len + 17) = new_cksum.u8[1];
> >>+ }
> >
> >The tcp header will always be in the mbuf, right? Otherwise, you can't
> >update the cksum field here. What's the point of introducing the "else
> >clause" then?
>
> Sorry, I don't see the problem you're pointing out here.
>
> What I want to solve here is to support the cases where the mbuf is
> segmented in the middle of the network header (which is probably a rare
> case).
How it's gonna segmented?
>
> In the "else" part, I only access the mbuf byte by byte using the
> rte_pktmbuf_mtod_offset() accessor. An alternative would have been to copy
> the header in a linear buffer, fix the checksum, then copy it again in the
> packet, but there is no mbuf helpers to do these copies for now.
In the "else" clause, the ip header is still in the mbuf, right?
Why do you have to access it the way like:
ip_version = *rte_pktmbuf_mtod_offset(m, uint8_t *,
m->l2_len) >> 4;
Why can't you just use
iph = rte_pktmbuf_mtod_offset(m, struct ipv4_hdr *, m->l2_len);
iph->version_ihl ....;
Sorry, I'm just a bit lost.
--yliu
next prev parent reply other threads:[~2016-10-13 14:16 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 offload support 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
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 [this message]
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
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