From: "Michael S. Tsirkin" <mst@redhat•com>
To: Jason Wang <jasowang@redhat•com>
Cc: "Xuan Zhuo" <xuanzhuo@linux•alibaba.com>,
netdev@vger•kernel.org, "Eugenio Pérez" <eperezma@redhat•com>,
"Andrew Lunn" <andrew+netdev@lunn•ch>,
"David S. Miller" <davem@davemloft•net>,
"Eric Dumazet" <edumazet@google•com>,
"Jakub Kicinski" <kuba@kernel•org>,
"Paolo Abeni" <pabeni@redhat•com>,
"Heng Qi" <hengqi@linux•alibaba.com>,
"Willem de Bruijn" <willemb@google•com>,
"Jiri Pirko" <jiri@resnulli•us>,
"Alvaro Karsz" <alvaro.karsz@solid-run•com>,
virtualization@lists•linux.dev
Subject: Re: [PATCH net v4 3/4] virtio-net: correct hdr_len handling for VIRTIO_NET_F_GUEST_HDRLEN
Date: Mon, 10 Nov 2025 02:26:57 -0500 [thread overview]
Message-ID: <20251110022550-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <CACGkMEtxfZh=66TSTC2B8TdXWP-fsTrYFkfz5aOViYkZmmcvxg@mail.gmail.com>
On Mon, Nov 10, 2025 at 03:16:08PM +0800, Jason Wang wrote:
> On Mon, Nov 10, 2025 at 5:41 AM Michael S. Tsirkin <mst@redhat•com> wrote:
> >
> > On Thu, Oct 30, 2025 at 10:53:01AM +0800, Jason Wang wrote:
> > > On Wed, Oct 29, 2025 at 11:09 AM Xuan Zhuo <xuanzhuo@linux•alibaba.com> wrote:
> > > >
> > > > The commit be50da3e9d4a ("net: virtio_net: implement exact header length
> > > > guest feature") introduces support for the VIRTIO_NET_F_GUEST_HDRLEN
> > > > feature in virtio-net.
> > > >
> > > > This feature requires virtio-net to set hdr_len to the actual header
> > > > length of the packet when transmitting, the number of
> > > > bytes from the start of the packet to the beginning of the
> > > > transport-layer payload.
> > > >
> > > > However, in practice, hdr_len was being set using skb_headlen(skb),
> > > > which is clearly incorrect. This commit fixes that issue.
> > >
> > > I still think it would be more safe to check the feature
> >
> > which feature VIRTIO_NET_F_GUEST_HDRLEN ?
> >
>
> Yes.
>
> Thanks
Seems more conservative for sure, though an extra mode to maintain isn't
great. Hmm?
--
MST
next prev parent reply other threads:[~2025-11-10 7:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-29 3:09 [PATCH net v4 0/4] fixes two virtio-net related bugs Xuan Zhuo
2025-10-29 3:09 ` [PATCH net v4 1/4] virtio-net: fix incorrect flags recording in big mode Xuan Zhuo
2025-11-09 17:04 ` Alyssa Ross
2025-11-09 21:34 ` Michael S. Tsirkin
2025-10-29 3:09 ` [PATCH net v4 2/4] virtio-net: Ensure hdr_len is not set unless the header is forwarded to the device Xuan Zhuo
2025-10-30 2:42 ` Jason Wang
2025-11-09 21:37 ` Michael S. Tsirkin
2025-10-29 3:09 ` [PATCH net v4 3/4] virtio-net: correct hdr_len handling for VIRTIO_NET_F_GUEST_HDRLEN Xuan Zhuo
2025-10-30 2:53 ` Jason Wang
2025-11-09 21:41 ` Michael S. Tsirkin
2025-11-10 7:16 ` Jason Wang
2025-11-10 7:26 ` Michael S. Tsirkin [this message]
2025-11-10 7:39 ` Jason Wang
2025-11-10 16:10 ` Michael S. Tsirkin
2025-11-11 0:45 ` Jason Wang
2025-11-09 21:42 ` Michael S. Tsirkin
2025-10-29 3:09 ` [PATCH net v4 4/4] virtio-net: correct hdr_len handling for tunnel gso Xuan Zhuo
2025-10-29 9:51 ` Paolo Abeni
2025-10-30 8:02 ` [PATCH net v4 0/4] fixes two virtio-net related bugs Michael S. Tsirkin
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