From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:57727) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvV9P-0007nG-O2 for qemu-devel@nongnu.org; Wed, 16 Jan 2013 10:43:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TvV9M-0003BG-SZ for qemu-devel@nongnu.org; Wed, 16 Jan 2013 10:43:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39951) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TvOuW-0001HG-4r for qemu-devel@nongnu.org; Wed, 16 Jan 2013 04:03:52 -0500 Date: Wed, 16 Jan 2013 11:07:48 +0200 From: "Michael S. Tsirkin" Message-ID: <20130116090748.GA12723@redhat.com> References: <1358315821-29519-1-git-send-email-akong@redhat.com> <1358317007-29972-1-git-send-email-akong@redhat.com> <1793480.zqgr4LeT19@jason-thinkpad-t430s> <20130116085914.GC6693@stefanha-thinkpad.hitronhub.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130116085914.GC6693@stefanha-thinkpad.hitronhub.home> Subject: Re: [Qemu-devel] [QEMU PATCH v2] virtio-net: introduce a new macaddr control List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Jason Wang , akong@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org On Wed, Jan 16, 2013 at 09:59:14AM +0100, Stefan Hajnoczi wrote: > On Wed, Jan 16, 2013 at 02:37:34PM +0800, Jason Wang wrote: > > On Wednesday, January 16, 2013 02:16:47 PM akong@redhat.com wrote: > > > From: Amos Kong > > > > > > In virtio-net guest driver, 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 > > > --- > > > V2: check guest's iov_len before memcpy > > > --- > > > hw/virtio-net.c | 10 ++++++++++ > > > hw/virtio-net.h | 9 ++++++++- > > > 2 files changed, 18 insertions(+), 1 deletion(-) > > > > > > diff --git a/hw/virtio-net.c b/hw/virtio-net.c > > > index dc7c6d6..d05f98f 100644 > > > --- a/hw/virtio-net.c > > > +++ b/hw/virtio-net.c > > > @@ -247,6 +247,7 @@ static uint32_t virtio_net_get_features(VirtIODevice > > > *vdev, uint32_t features) VirtIONet *n = to_virtio_net(vdev); > > > > > > features |= (1 << VIRTIO_NET_F_MAC); > > > + features |= (1 << VIRTIO_NET_F_CTRL_MAC_ADDR); > > > > > > if (!peer_has_vnet_hdr(n)) { > > > features &= ~(0x1 << VIRTIO_NET_F_CSUM); > > > @@ -282,6 +283,7 @@ static uint32_t virtio_net_bad_features(VirtIODevice > > > *vdev) /* Linux kernel 2.6.25. It understood MAC (as everyone must), * but > > > also these: */ > > > features |= (1 << VIRTIO_NET_F_MAC); > > > + features |= (1 << VIRTIO_NET_F_CTRL_MAC_ADDR); > > > features |= (1 << VIRTIO_NET_F_CSUM); > > > features |= (1 << VIRTIO_NET_F_HOST_TSO4); > > > features |= (1 << VIRTIO_NET_F_HOST_TSO6); > > > @@ -349,6 +351,14 @@ static int virtio_net_handle_mac(VirtIONet *n, uint8_t > > > cmd, { > > > struct virtio_net_ctrl_mac mac_data; > > > > > > + if (cmd == VIRTIO_NET_CTRL_MAC_ADDR_SET && elem->out_num == 2 && > > > + elem->out_sg[1].iov_len == ETH_ALEN) { > > > + /* Set MAC address */ > > > + memcpy(n->mac, elem->out_sg[1].iov_base, elem->out_sg[1].iov_len); > > > + qemu_format_nic_info_str(&n->nic->nc, n->mac); > > > + return VIRTIO_NET_OK; > > > + } > > > + > > > if (cmd != VIRTIO_NET_CTRL_MAC_TABLE_SET || elem->out_num != 3 || > > > elem->out_sg[1].iov_len < sizeof(mac_data) || > > > elem->out_sg[2].iov_len < sizeof(mac_data)) > > > diff --git a/hw/virtio-net.h b/hw/virtio-net.h > > > index d46fb98..9394cc0 100644 > > > --- a/hw/virtio-net.h > > > +++ b/hw/virtio-net.h > > > @@ -44,6 +44,8 @@ > > > #define VIRTIO_NET_F_CTRL_VLAN 19 /* Control channel VLAN filtering > > > */ #define VIRTIO_NET_F_CTRL_RX_EXTRA 20 /* Extra RX mode control support > > > */ > > > > > > +#define VIRTIO_NET_F_CTRL_MAC_ADDR 23 /* Set MAC address */ > > > + > > > > I wonder whether we need a DEFINE_PROP_BIT to disable and compat this feature. > > Consider we may migrate from a new version to an old version. > > I agree, migration needs to be handled. The bit should never change > while the device is initialized and running. We should also never start > rejecting or ignoring the command if it was available before. > > Stefan It's the same for all feature bits. Soo all we need to do is clear them when running with a compat machine type.