DPDK usage discussions
 help / color / mirror / Atom feed
From: Stephen Hemminger <stephen@networkplumber.org>
To: "jiangheng (G)" <jiangheng14@huawei.com>
Cc: "maxime.coquelin@redhat.com" <maxime.coquelin@redhat.com>,
	"chenbo.xia@intel.com" <chenbo.xia@intel.com>,
	"users@dpdk.org" <users@dpdk.org>
Subject: Re: why does virtio not support IPv4 CKSUM?
Date: Thu, 6 Jul 2023 07:37:37 -0700	[thread overview]
Message-ID: <20230706073737.24bc2201@hermes.local> (raw)
In-Reply-To: <a23d925dd0e84445a688ac9e53ef4da3@huawei.com>

On Thu, 6 Jul 2023 03:47:26 +0000
"jiangheng (G)" <jiangheng14@huawei.com> wrote:

> Hi 
> 
> why does virtio not support IPv4 CKSUM? But support TCP/UDP cksum.

Because virtio is a software driver developed on Linux and Linux doesn't need/want IP checksum offload.
It takes longer to look at offload bits then to compute checksum in SW.

> 
> If not support ipv4 cksum, when I use GRO, the ip cksum of the packets transmitted to ip layer will be incorrect.
> I have to calculate ip cksum before packet was transmiited to ip layer.
> So why does virtio not support ipv4 cksum ? 


  reply	other threads:[~2023-07-06 14:37 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-06  3:47 jiangheng (G)
2023-07-06 14:37 ` Stephen Hemminger [this message]
2023-07-07 12:21   ` 答复: " jiangheng (G)
2023-07-07 12:34     ` jiangheng (G)

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=20230706073737.24bc2201@hermes.local \
    --to=stephen@networkplumber.org \
    --cc=chenbo.xia@intel.com \
    --cc=jiangheng14@huawei.com \
    --cc=maxime.coquelin@redhat.com \
    --cc=users@dpdk.org \
    /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).