From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755057AbcCOUx3 (ORCPT ); Tue, 15 Mar 2016 16:53:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32891 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751312AbcCOUx1 (ORCPT ); Tue, 15 Mar 2016 16:53:27 -0400 From: Aaron Conole To: Sergei Shtylyov Cc: netdev@vger.kernel.org, "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [RFC -next 2/2] virtio_net: Read and use the advised MTU References: <1457620092-24170-1-git-send-email-aconole@redhat.com> <1457620092-24170-3-git-send-email-aconole@redhat.com> <56E1C372.60204@cogentembedded.com> Date: Tue, 15 Mar 2016 16:53:24 -0400 In-Reply-To: <56E1C372.60204@cogentembedded.com> (Sergei Shtylyov's message of "Thu, 10 Mar 2016 21:56:50 +0300") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Sergei Shtylyov writes: > Hello. Hi Sergei, > On 03/10/2016 05:28 PM, Aaron Conole wrote: > >> This patch checks the feature bit for the VIRTIO_NET_F_MTU feature. If it >> exists, read the advised MTU and use it. >> >> No proper error handling is provided for the case where a user changes the >> negotiated MTU. A future commit will add proper error handling. Instead, a >> warning is emitted if the guest changes the device MTU after previously being >> given advice. >> >> Signed-off-by: Aaron Conole >> --- >> drivers/net/virtio_net.c | 15 ++++++++++++++- >> 1 file changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index 767ab11..7175563 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c > [...] >> @@ -1390,8 +1391,12 @@ static const struct ethtool_ops virtnet_ethtool_ops = { >> >> static int virtnet_change_mtu(struct net_device *dev, int new_mtu) >> { >> + struct virtnet_info *vi = netdev_priv(dev); >> if (new_mtu < MIN_MTU || new_mtu > MAX_MTU) >> return -EINVAL; >> + if (vi->negotiated_mtu == true) { >> + pr_warn("changing mtu from negotiated mtu."); >> + } > > {} not needed, see Documentation/CodingStyle. Okay, I'll make sure to fix this with v2. > [...] > > MBR, Sergei Thanks so much for the review! -Aaron