From: "Michael S. Tsirkin" <mst@redhat.com>
To: John Fastabend <john.fastabend@gmail.com>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
virtualization@lists.linux-foundation.org
Subject: Re: [PATCH net-next] virito-net: set queues after reset during xdp_set
Date: Mon, 20 Feb 2017 02:12:18 +0200 [thread overview]
Message-ID: <20170220013627-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <58A787AB.6000201@gmail.com>
On Fri, Feb 17, 2017 at 03:30:51PM -0800, John Fastabend wrote:
> On 17-02-16 09:10 PM, Jason Wang wrote:
> >
> >
> > On 2017年02月17日 12:53, John Fastabend wrote:
> >> On 17-02-15 01:08 AM, Jason Wang wrote:
> >>> We set queues before reset which will cause a crash[1]. This is
> >>> because is_xdp_raw_buffer_queue() depends on the old xdp queue pairs
> >>> number to do the correct detection. So fix this by:
> >>>
> >>> - set queues after reset, to keep the old vi->curr_queue_pairs. (in
> >>> fact setting queues before reset does not works since after feature
> >>> set, all queue pairs were enabled by default during reset).
> >>> - change xdp_queue_pairs only after virtnet_reset() is succeed.
> >>>
> >>> [1]
> >> I'm guessing this occurs when enabling XDP while receiving lots of traffic?
> >
> > I hit this then disabling XDP while receiving lots of traffic.
> >
>
> [...]
>
> >>> + vi->xdp_queue_pairs = xdp_qp;
> >> But xdp_queue_pairs is being used to detect if we should allocate the XDP
> >> headroom. If we move it here do we have a set of buffers in the ring without
> >> the proper headroom when we assign the xdp program below?
> >
> > Right, so how about passing xdp_queue_pairs as a parameter to virtnet_reset().
> > Then virtnet_reset() can set it after _remove_vq_common() but before
> > virtnet_restore_up()?
> >
> > Thanks
> >
>
> Sounds like a reasonable fix to me.
I'm fine with that.
> >>
> >>> + }
> >>> +
> >>> + err = _virtnet_set_queues(vi, curr_qp + xdp_qp);
> >>> + if (err) {
> >>> + dev_warn(&dev->dev, "XDP Device queue allocation failure.\n");
> >>> + goto virtio_queue_err;
> >>> }
> >>> netif_set_real_num_rx_queues(dev, curr_qp + xdp_qp);
> >>> @@ -1844,17 +1844,18 @@ static int virtnet_xdp_set(struct net_device *dev,
> >>> struct bpf_prog *prog)
> >>> return 0;
> >> Thanks,
> >> John
> >>
> >
_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2017-02-20 0:12 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-15 9:08 [PATCH net-next] virito-net: set queues after reset during xdp_set Jason Wang
2017-02-16 17:21 ` Michael S. Tsirkin
2017-02-17 4:53 ` John Fastabend
2017-02-17 5:10 ` Jason Wang
2017-02-17 23:30 ` John Fastabend
2017-02-20 0:12 ` Michael S. Tsirkin [this message]
2017-02-19 5:08 ` Michael S. Tsirkin
2017-02-20 3:47 ` 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=20170220013627-mutt-send-email-mst@kernel.org \
--to=mst@redhat.com \
--cc=john.fastabend@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.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).