From: Anthony Liguori <aliguori@linux.vnet.ibm.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Shirley Ma <mashirle@us.ibm.com>,
Rusty Russell <rusty@rustcorp.com.au>,
qemu-devel@nongnu.org
Subject: [Qemu-devel] Re: [PATCH] qemu/virtio-net: remove wrong s/g layout assumptions
Date: Tue, 24 Nov 2009 13:50:25 -0600 [thread overview]
Message-ID: <4B0C3901.5010100@linux.vnet.ibm.com> (raw)
In-Reply-To: <20091124194502.GA4250@redhat.com>
Michael S. Tsirkin wrote:
> virtio net currently assumes that the first s/g element it gets is
> always virtio net header. This is wrong.
> There should be no assumption on sg boundaries. For example, the guest
> should be able to put the virtio_net_hdr in the front of the skbuf data
> if there is room. Get rid of this assumption, properly consume space
> from iovec, always.
>
Practically speaking, we ought to advertise a feature bit to let a
kernel know that we are no longer broken.
Otherwise, there are a ton of old userspaces that will break with new
guests.
--
Regards,
Anthony Liguori
next prev parent reply other threads:[~2009-11-24 19:50 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-24 19:45 [Qemu-devel] [PATCH] qemu/virtio-net: remove wrong s/g layout assumptions Michael S. Tsirkin
2009-11-24 19:50 ` Anthony Liguori [this message]
2009-11-24 19:54 ` [Qemu-devel] " Michael S. Tsirkin
2009-11-24 21:04 ` Anthony Liguori
2009-11-24 21:30 ` Michael S. Tsirkin
2009-11-24 21:57 ` Anthony Liguori
2009-11-24 22:20 ` Michael S. Tsirkin
2009-11-30 11:16 ` Michael S. Tsirkin
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=4B0C3901.5010100@linux.vnet.ibm.com \
--to=aliguori@linux.vnet.ibm.com \
--cc=mashirle@us.ibm.com \
--cc=mst@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=rusty@rustcorp.com.au \
/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).