From: David Miller <davem@davemloft.net>
To: markmc@redhat.com
Cc: alex.williamson@hp.com, netdev@vger.kernel.org,
rusty@rustcorp.com.au, kvm@vger.kernel.org
Subject: Re: [PATCH] virtio_net: Fix MAX_PACKET_LEN to support 802.1Q VLANs
Date: Sun, 25 Jan 2009 18:06:43 -0800 (PST) [thread overview]
Message-ID: <20090125.180643.147283270.davem@davemloft.net> (raw)
In-Reply-To: <1232470766.5277.18.camel@blaa>
From: Mark McLoughlin <markmc@redhat.com>
Date: Tue, 20 Jan 2009 16:59:26 +0000
> On Tue, 2009-01-20 at 09:48 -0700, Alex Williamson wrote:
>
> > 802.1Q expanded the maximum ethernet frame size by 4 bytes for the
> > VLAN tag. We're not taking this into account in virtio_net, which
> > means the buffers we provide to the backend in the virtqueue RX ring
> > aren't big enough to hold a full MTU VLAN packet. For QEMU/KVM,
> > this results in the backend exiting with a packet truncation error.
> >
> > Signed-off-by: Alex Williamson <alex.williamson@hp.com>
>
> Acked-by: Mark McLoughlin <markmc@redhat.com>
>
> Note 1: this only matters if the guest isn't using mergeable receive
> buffers or GSO
>
> Note 2: IMHO, this should go in 2.6.29 and stable
Applied and queued up for -stable, thanks everyone!
prev parent reply other threads:[~2009-01-26 2:06 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-20 16:48 [PATCH] virtio_net: Fix MAX_PACKET_LEN to support 802.1Q VLANs Alex Williamson
2009-01-20 16:59 ` Mark McLoughlin
2009-01-26 2:06 ` David Miller [this message]
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