2 files changed, 54 insertions, 25 deletions

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index f87c79824b..b21e7a434f 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -115,6 +115,7 @@ unsigned vhost_net_get_features(struct vhost_net *net, unsigned features)
 
 void vhost_net_ack_features(struct vhost_net *net, unsigned features)
 {
+    net->dev.acked_features = net->dev.backend_features;
     vhost_ack_features(&net->dev, vhost_net_get_feature_bits(net), features);
 }
 
@@ -188,20 +189,19 @@ bool vhost_net_query(VHostNetState *net, VirtIODevice *dev)
     return vhost_dev_query(&net->dev, dev);
 }
 
+static void vhost_net_set_vq_index(struct vhost_net *net, int vq_index)
+{
+    net->dev.vq_index = vq_index;
+}
+
 static int vhost_net_start_one(struct vhost_net *net,
-                               VirtIODevice *dev,
-                               int vq_index)
+                               VirtIODevice *dev)
 {
     struct vhost_vring_file file = { };
     int r;
 
-    if (net->dev.started) {
-        return 0;
-    }
-
     net->dev.nvqs = 2;
     net->dev.vqs = net->vqs;
-    net->dev.vq_index = vq_index;
 
     r = vhost_dev_enable_notifiers(&net->dev, dev);
     if (r < 0) {
@@ -256,10 +256,6 @@ static void vhost_net_stop_one(struct vhost_net *net,
 {
     struct vhost_vring_file file = { .fd = -1 };
 
-    if (!net->dev.started) {
-        return;
-    }
-
     if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP) {
         for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
             const VhostOps *vhost_ops = net->dev.vhost_ops;
@@ -294,7 +290,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
     VirtioBusState *vbus = VIRTIO_BUS(qbus);
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
-    int r, i = 0;
+    int r, e, i;
 
     if (!vhost_net_device_endian_ok(dev)) {
         error_report("vhost-net does not support cross-endian");
@@ -309,11 +305,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (i = 0; i < total_queues; i++) {
-        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev, i * 2);
-
-        if (r < 0) {
-            goto err;
-        }
+        vhost_net_set_vq_index(get_vhost_net(ncs[i].peer), i * 2);
     }
 
     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
@@ -322,12 +314,26 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
         goto err;
     }
 
+    for (i = 0; i < total_queues; i++) {
+        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
+
+        if (r < 0) {
+            goto err_start;
+        }
+    }
+
     return 0;
 
-err:
+err_start:
     while (--i >= 0) {
         vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
     }
+    e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
+    if (e < 0) {
+        fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
+        fflush(stderr);
+    }
+err:
     return r;
 }
 
@@ -339,16 +345,16 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
     int i, r;
 
+    for (i = 0; i < total_queues; i++) {
+        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
+    }
+
     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
     if (r < 0) {
         fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", r);
         fflush(stderr);
     }
     assert(r >= 0);
-
-    for (i = 0; i < total_queues; i++) {
-        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
-    }
 }
 
 void vhost_net_cleanup(struct vhost_net *net)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 268eff9df8..826a2a5fca 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) {
@@ -1224,7 +1237,12 @@ static void virtio_net_tx_timer(void *opaque)
     VirtIONetQueue *q = opaque;
     VirtIONet *n = q->n;
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
-    assert(vdev->vm_running);
+    /* This happens when device was stopped but BH wasn't. */
+    if (!vdev->vm_running) {
+        /* Make sure tx waiting is set, so we'll run when restarted. */
+        assert(q->tx_waiting);
+        return;
+    }
 
     q->tx_waiting = 0;
 
@@ -1244,7 +1262,12 @@ static void virtio_net_tx_bh(void *opaque)
     VirtIODevice *vdev = VIRTIO_DEVICE(n);
     int32_t ret;
 
-    assert(vdev->vm_running);
+    /* This happens when device was stopped but BH wasn't. */
+    if (!vdev->vm_running) {
+        /* Make sure tx waiting is set, so we'll run when restarted. */
+        assert(q->tx_waiting);
+        return;
+    }
 
     q->tx_waiting = 0;