From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41212) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XPSWX-00076G-Tb for qemu-devel@nongnu.org; Thu, 04 Sep 2014 04:36:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XPSWS-0005eK-Nf for qemu-devel@nongnu.org; Thu, 04 Sep 2014 04:36:09 -0400 Date: Thu, 4 Sep 2014 11:39:17 +0300 From: "Michael S. Tsirkin" Message-ID: <1409816839-12309-3-git-send-email-mst@redhat.com> References: <1409816839-12309-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1409816839-12309-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PATCH 3/3] virtio-net: purge outstanding packets when starting vhost List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jason Wang , Stefan Hajnoczi , qemu-stable@nongnu.org, Anthony Liguori whenever we start vhost, virtio could have outstanding packets queued, when they complete later we'll modify the ring while vhost is processing it. To prevent this, purge outstanding packets on vhost start. Cc: qemu-stable@nongnu.org Cc: Jason Wang Signed-off-by: Michael S. Tsirkin --- hw/net/virtio-net.c | 15 ++++++++++++++- net/net.c | 1 + 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 365e266..826a2a5 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -125,10 +125,23 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status) return; } if (!n->vhost_started) { - int r; + int r, i; + if (!vhost_net_query(get_vhost_net(nc->peer), vdev)) { return; } + + /* Any packets outstanding? Purge them to avoid touching rings + * when vhost is running. + */ + for (i = 0; i < queues; i++) { + NetClientState *qnc = qemu_get_subqueue(n->nic, i); + + /* Purge both directions: TX and RX. */ + qemu_net_queue_purge(qnc->peer->incoming_queue, qnc); + qemu_net_queue_purge(qnc->incoming_queue, qnc->peer); + } + n->vhost_started = 1; r = vhost_net_start(vdev, n->nic->ncs, queues); if (r < 0) { diff --git a/net/net.c b/net/net.c index 25fdb07..b94473e 100644 --- a/net/net.c +++ b/net/net.c @@ -41,6 +41,7 @@ #include "qapi-visit.h" #include "qapi/opts-visitor.h" #include "qapi/dealloc-visitor.h" +#include "sysemu/sysemu.h" /* Net bridge is currently not supported for W32. */ #if !defined(_WIN32) -- MST