From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161600AbcFBRKa (ORCPT ); Thu, 2 Jun 2016 13:10:30 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41988 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752020AbcFBRK1 (ORCPT ); Thu, 2 Jun 2016 13:10:27 -0400 From: Aaron Conole To: "Michael S. Tsirkin" Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -next 2/2] virtio_net: Read the advised MTU References: <1464882211-18723-1-git-send-email-aconole@redhat.com> <1464882211-18723-3-git-send-email-aconole@redhat.com> <20160602191632-mutt-send-email-mst@redhat.com> Date: Thu, 02 Jun 2016 13:10:25 -0400 In-Reply-To: <20160602191632-mutt-send-email-mst@redhat.com> (Michael S. Tsirkin's message of "Thu, 2 Jun 2016 19:16:57 +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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Thu, 02 Jun 2016 17:10:26 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "Michael S. Tsirkin" writes: > On Thu, Jun 02, 2016 at 11:43:31AM -0400, 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. > > I don't see a warning and I don't think it's needed. > Patch is ok commit log isn't. Okay, I'll fix it when I submit v2. >> Signed-off-by: Aaron Conole >> --- >> drivers/net/virtio_net.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c >> index e0638e5..ef5ee01 100644 >> --- a/drivers/net/virtio_net.c >> +++ b/drivers/net/virtio_net.c >> @@ -1896,6 +1896,12 @@ static int virtnet_probe(struct virtio_device *vdev) >> if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ)) >> vi->has_cvq = true; >> >> + if (virtio_has_feature(vdev, VIRTIO_NET_F_MTU)) { >> + dev->mtu = virtio_cread16(vdev, >> + offsetof(struct virtio_net_config, >> + mtu)); >> + } >> + >> if (vi->any_header_sg) >> dev->needed_headroom = vi->hdr_len; >> >> @@ -2067,6 +2073,7 @@ static unsigned int features[] = { >> VIRTIO_NET_F_GUEST_ANNOUNCE, VIRTIO_NET_F_MQ, >> VIRTIO_NET_F_CTRL_MAC_ADDR, >> VIRTIO_F_ANY_LAYOUT, >> + VIRTIO_NET_F_MTU, >> }; >> >> static struct virtio_driver virtio_net_driver = { >> -- >> 2.5.5