From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:58817) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvRqv-0001oX-5R for qemu-devel@nongnu.org; Wed, 16 Jan 2013 07:12:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TvRqs-0006DT-A3 for qemu-devel@nongnu.org; Wed, 16 Jan 2013 07:12:21 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36511) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvP3a-000308-5p for qemu-devel@nongnu.org; Wed, 16 Jan 2013 04:13:14 -0500 Date: Wed, 16 Jan 2013 11:17:09 +0200 From: "Michael S. Tsirkin" Message-ID: <20130116091709.GB12723@redhat.com> References: <1357829141-25455-1-git-send-email-akong@redhat.com> <1357829141-25455-3-git-send-email-akong@redhat.com> <50EED6C1.1040608@redhat.com> <20130116052326.GA4279@t430s.nay.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130116052326.GA4279@t430s.nay.redhat.com> Subject: Re: [Qemu-devel] [RFC PATCH 2/2] virtio-net: introduce a new control to set macaddr List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amos Kong Cc: Jason Wang , rusty@rustcorp.com.au, qemu-devel@nongnu.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org On Wed, Jan 16, 2013 at 01:23:26PM +0800, Amos Kong wrote: > On Thu, Jan 10, 2013 at 10:57:05PM +0800, Jason Wang wrote: > > On 01/10/2013 10:45 PM, akong@redhat.com wrote: > > > From: Amos Kong > > > > > > Currently we write MAC address to pci config space byte by byte, > > > this means that we have an intermediate step where mac is wrong. > > > This patch introduced a new control command to set MAC address > > > in one time. > > > > > > VIRTIO_NET_F_CTRL_MAC_ADDR is a new feature bit for compatibility. > > > > > > Signed-off-by: Amos Kong > > > --- > > > drivers/net/virtio_net.c | 16 +++++++++++++++- > > > include/uapi/linux/virtio_net.h | 8 +++++++- > > > 2 files changed, 22 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > > index 395ab4f..ff22bcd 100644 > > > --- a/drivers/net/virtio_net.c > > > +++ b/drivers/net/virtio_net.c > > > @@ -803,13 +803,26 @@ static int virtnet_set_mac_address(struct net_device *dev, void *p) > > > struct virtio_device *vdev = vi->vdev; > > > int ret; > > > > > > + struct scatterlist sg; > > > + > > > ret = eth_mac_addr(dev, p); > > > if (ret) > > > return ret; > > > > > > - if (virtio_has_feature(vdev, VIRTIO_NET_F_MAC)) > > > + if (virtio_has_feature(vdev, VIRTIO_NET_F_CTRL_MAC_ADDR)) { > > > + /* Set MAC address by sending vq command */ > > > + sg_init_one(&sg, dev->dev_addr, dev->addr_len); > > > + virtnet_send_command(vi, VIRTIO_NET_CTRL_MAC, > > > + VIRTIO_NET_CTRL_MAC_ADDR_SET, > > > + &sg, 1, 0); > > > + return 0; > > > + } > > > + > > > > Better to check the return of virtnet_send_command() and give a warn > > like other command. Btw, need we fail back to try the old way then? > > Yes, it's necessary to check the return value of > virtnet_send_command(). > > In fail case, I like to return -EINVAL to userspace, because we don't > only want to set mac successfully, we also want to resolve the > addr inconsistent issue by this feature (vq cmd). It's really a device error but I guess we can. We probably should print a warning too. -- MST