From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:42639) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c2co3-0001kG-Jt for qemu-devel@nongnu.org; Fri, 04 Nov 2016 07:37:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c2co0-0007mI-G4 for qemu-devel@nongnu.org; Fri, 04 Nov 2016 07:37:11 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:38383 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1c2co0-0007mA-8z for qemu-devel@nongnu.org; Fri, 04 Nov 2016 07:37:08 -0400 Received: from pps.filterd (m0098419.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id uA4BZpFg023513 for ; Fri, 4 Nov 2016 07:37:07 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 26gqjsffcu-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 04 Nov 2016 07:37:07 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 4 Nov 2016 11:37:05 -0000 Date: Fri, 4 Nov 2016 12:37:02 +0100 From: Cornelia Huck In-Reply-To: <1478257275-30365-3-git-send-email-mst@redhat.com> 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-Transfer-Encoding: 7bit Message-Id: <20161104123702.0f5427c7.cornelia.huck@de.ibm.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 , dgilbert@redhat.com, qemu-stable@nongnu.org On Fri, 4 Nov 2016 13:01:40 +0200 "Michael S. Tsirkin" 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. This also means that guest may see a different feature set if it is e.g. rebooted after migration. But I agree that this should not be an issue. > > Cc: qemu-stable@nongnu.org You also need to cc: the previous patch to stable. > 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 = { Reviewed-by: Cornelia Huck