From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: virtio-dev@lists.oasis-open.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org,
Sridhar Samudrala <sri@us.ibm.com>
Subject: Re: [PATCH net] virtio-net: alloc big buffers also when guest can receive UFO
Date: Thu, 13 Feb 2014 07:15:59 +0200 [thread overview]
Message-ID: <20140213051559.GB31352@redhat.com> (raw)
In-Reply-To: <52FC35B5.6000900@redhat.com>
On Thu, Feb 13, 2014 at 11:02:13AM +0800, Jason Wang wrote:
> On 02/12/2014 07:59 PM, Michael S. Tsirkin wrote:
> > On Wed, Feb 12, 2014 at 01:43:28PM +0800, Jason Wang wrote:
> >> > We should alloc big buffers also when guest can receive UFO
> >> > pakcets. Otherwise the big packets will be truncated when mergeable rx
> >> > buffer is disabled.
> > Not truncated, they will be dropped.
> >
>
> Why dropped? We enable the ufo on tap0 if VIRTIO_NET_F_GUEST_UFO is
> negotiated. So skb was queued on the receive queue. But since the
> receive buffer is small, it will be truncated during tun_put_user().
Hypervisor shouldn't truncate packets silently - if it does
it's a hypervisor bug. Passing malformed packets to guest is
a bad idea.
--
MST
next prev parent reply other threads:[~2014-02-13 5:15 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-12 5:43 [PATCH net] virtio-net: alloc big buffers also when guest can receive UFO Jason Wang
2014-02-12 11:59 ` Michael S. Tsirkin
2014-02-13 3:02 ` Jason Wang
2014-02-13 5:15 ` Michael S. Tsirkin [this message]
2014-02-13 5:40 ` Jason Wang
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=20140213051559.GB31352@redhat.com \
--to=mst@redhat.com \
--cc=jasowang@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=sri@us.ibm.com \
--cc=virtio-dev@lists.oasis-open.org \
--cc=virtualization@lists.linux-foundation.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).