From nobody Fri Nov 7 10:16:23 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1547664046388720.5735375159333; Wed, 16 Jan 2019 10:40:46 -0800 (PST) Received: from localhost ([127.0.0.1]:45558 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gjq7F-0000hA-EV for importer@patchew.org; Wed, 16 Jan 2019 13:40:41 -0500 Received: from eggs.gnu.org ([209.51.188.92]:47204) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gjpzT-0003Zv-Rn for qemu-devel@nongnu.org; Wed, 16 Jan 2019 13:32:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gjpzR-0007qr-2k for qemu-devel@nongnu.org; Wed, 16 Jan 2019 13:32:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51490) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gjpzJ-0007ku-QK for qemu-devel@nongnu.org; Wed, 16 Jan 2019 13:32:31 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A605381F12; Wed, 16 Jan 2019 18:32:25 +0000 (UTC) Received: from dell-per430-12.lab.eng.pek2.redhat.com (dell-per430-12.lab.eng.pek2.redhat.com [10.73.196.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 205BF5C1B4; Wed, 16 Jan 2019 18:32:22 +0000 (UTC) From: wexu@redhat.com To: wexu@redhat.com, tiwei.bie@intel.com, qemu-devel@nongnu.org Date: Wed, 16 Jan 2019 13:31:15 -0500 Message-Id: <1547663480-547-11-git-send-email-wexu@redhat.com> In-Reply-To: <1547663480-547-1-git-send-email-wexu@redhat.com> References: <1547663480-547-1-git-send-email-wexu@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 16 Jan 2019 18:32:25 +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] [PATCH v2 10/15] virtio-net: fill head desc after done all in a chain 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: jasowang@redhat.com, maxime.coquelin@redhat.com, jfreiman@redhat.com, mst@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Wei Xu With the support of marking a descriptor used/unused in 'flags' field for 1.1, the current way of filling a chained descriptors does not work since driver side may get the wrong 'num_buffer' information in case of the head descriptor has been filled in while the subsequent ones are still in processing in device side. This patch fills the head one after done all the others one. Signed-off-by: Wei Xu --- hw/net/virtio-net.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index e37fc34..39336b9 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -1198,6 +1198,8 @@ static ssize_t virtio_net_receive_rcu(NetClientState = *nc, const uint8_t *buf, struct virtio_net_hdr_mrg_rxbuf mhdr; unsigned mhdr_cnt =3D 0; size_t offset, i, guest_offset; + VirtQueueElement head; + int head_len =3D 0; =20 if (!virtio_net_can_receive(nc)) { return -1; @@ -1275,7 +1277,13 @@ static ssize_t virtio_net_receive_rcu(NetClientState= *nc, const uint8_t *buf, } =20 /* signal other side */ - virtqueue_fill(q->rx_vq, elem, total, i++); + if (i =3D=3D 0) { + head_len =3D total; + head =3D *elem; + } else { + virtqueue_fill(q->rx_vq, elem, len, i); + } + i++; g_free(elem); } =20 @@ -1286,6 +1294,7 @@ static ssize_t virtio_net_receive_rcu(NetClientState = *nc, const uint8_t *buf, &mhdr.num_buffers, sizeof mhdr.num_buffers); } =20 + virtqueue_fill(q->rx_vq, &head, head_len, 0); virtqueue_flush(q->rx_vq, i); virtio_notify(vdev, q->rx_vq); =20 --=20 1.8.3.1