From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41729) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c3m0m-0005Ti-8a for qemu-devel@nongnu.org; Mon, 07 Nov 2016 10:39:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c3m0g-0000QS-IN for qemu-devel@nongnu.org; Mon, 07 Nov 2016 10:39:04 -0500 Date: Mon, 7 Nov 2016 15:38:53 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20161107153853.GF2054@work-vm> References: <1478257275-30365-1-git-send-email-mst@redhat.com> <1478257275-30365-3-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1478257275-30365-3-git-send-email-mst@redhat.com> Subject: Re: [Qemu-devel] [PATCH 2/2] virtio-net: mark VIRTIO_NET_F_GSO as legacy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org, Jason Wang , qemu-stable@nongnu.org * Michael S. Tsirkin (mst@redhat.com) wrote: > virtio 1.0 spec says this is a legacy feature bit, > hide it from guests in legacy mode. > > Note: for cross-version migration compatibility, > we keep the bit set in host_features. > The result will be that a guest migrating cross-version > will see host features change under it. > As guests only seem to read it once, this should > not be an issue. Meanwhile, will work to fix guests to > ignore this bit in virtio1 mode, too. OK, but if they're actually using the feature they'll carry on working ? Dave > Cc: qemu-stable@nongnu.org > Signed-off-by: Michael S. Tsirkin > --- > hw/net/virtio-net.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c > index 20aa63e..b68c69d 100644 > --- a/hw/net/virtio-net.c > +++ b/hw/net/virtio-net.c > @@ -1942,6 +1942,7 @@ static void virtio_net_class_init(ObjectClass *klass, void *data) > vdc->guest_notifier_pending = virtio_net_guest_notifier_pending; > vdc->load = virtio_net_load_device; > vdc->save = virtio_net_save_device; > + vdc->legacy_features |= (0x1 << VIRTIO_NET_F_GSO); > } > > static const TypeInfo virtio_net_info = { > -- > MST > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK