virtio-net: stop vhost backend on vmstop

vhost net currently keeps running after vmstop,
which causes trouble as qemy does not check
for dirty pages anymore.
The fix is to simply keep vm and vhost running/stopped
status in sync.

Tested-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index cb664e6..6a9d560 100644 (file)
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -877,12 +877,11 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
 static void virtio_net_vmstate_change(void *opaque, int running, int reason)
 {
     VirtIONet *n = opaque;
-    if (!running) {
-        return;
-    }
-    /* This is called when vm is started, it will start vhost backend if
-     * appropriate e.g. after migration. */
-    virtio_net_set_status(&n->vdev, n->vdev.status);
+    uint8_t status = running ? VIRTIO_CONFIG_S_DRIVER_OK : 0;
+    /* This is called when vm is started/stopped,
+     * it will start/stop vhost backend if * appropriate
+     * e.g. after migration. */
+    virtio_net_set_status(&n->vdev, n->vdev.status & status);
 }
 
 VirtIODevice *virtio_net_init(DeviceState *dev, NICConf *conf)