From patchwork Mon Jul 4 16:46:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 9212981 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 61DC060572 for ; Mon, 4 Jul 2016 17:00:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F000286CA for ; Mon, 4 Jul 2016 17:00:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4129728748; Mon, 4 Jul 2016 17:00:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A2B83286CA for ; Mon, 4 Jul 2016 17:00:33 +0000 (UTC) Received: from localhost ([::1]:49273 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bK7EW-0000A6-PU for patchwork-qemu-devel@patchwork.kernel.org; Mon, 04 Jul 2016 13:00:32 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39835) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bK71E-0001bW-Kz for qemu-devel@nongnu.org; Mon, 04 Jul 2016 12:46:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bK71C-00028G-LL for qemu-devel@nongnu.org; Mon, 04 Jul 2016 12:46:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33301) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bK71C-000282-Fz; Mon, 04 Jul 2016 12:46:46 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DFC4FC049E1B; Mon, 4 Jul 2016 16:46:45 +0000 (UTC) Received: from redhat.com (vpn1-6-134.ams2.redhat.com [10.36.6.134]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with SMTP id u64Gkhh2012287; Mon, 4 Jul 2016 12:46:44 -0400 Date: Mon, 4 Jul 2016 19:46:43 +0300 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <20160704194643-mutt-send-email-mst@redhat.com> References: <1467650742-17580-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1467650742-17580-1-git-send-email-mst@redhat.com> X-Mutt-Fcc: =sent X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 04 Jul 2016 16:46:46 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 10/36] virtio: set low features early on load X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Robin Geuze , qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP virtio migrates the low 32 feature bits twice, the first copy is there for compatibility but ever since 019a3edbb25f1571e876f8af1ce4c55412939e5d: ("virtio: make features 64bit wide") it's ignored on load. This is wrong since virtio_net_load tests self announcement and guest offloads before the second copy including high feature bits is loaded. This means that self announcement, control vq and guest offloads are all broken after migration. Fix it up by loading low feature bits: somewhat ugly since high and low bits become out of sync temporarily, but seems unavoidable for compatibility. The right thing to do for new features is probably to test the host features, anyway. Fixes: 019a3edbb25f1571e876f8af1ce4c55412939e5d ("virtio: make features 64bit wide") Cc: qemu-stable@nongnu.org Reported-by: Robin Geuze Tested-by: Robin Geuze Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 7ed06ea..18153d5 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1499,6 +1499,16 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) } qemu_get_be32s(f, &features); + /* + * Temporarily set guest_features low bits - needed by + * virtio net load code testing for VIRTIO_NET_F_CTRL_GUEST_OFFLOADS + * VIRTIO_NET_F_GUEST_ANNOUNCE and VIRTIO_NET_F_CTRL_VQ. + * + * Note: devices should always test host features in future - don't create + * new dependencies like this. + */ + vdev->guest_features = features; + config_len = qemu_get_be32(f); /*