[Qemu-devel] [PATCH 07/18] vhost: add vhost_dev stop callback

[marcandre.lureau@redhat.com]

From: Marc-André Lureau <marcandre.lureau@redhat.com>

vhost backend may want to stop the device, for example if it wants to
restart itself (translates to a link down for vhost-net).

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 hw/net/vhost_net.c        | 14 ++++++++++++++
 include/hw/virtio/vhost.h |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 6e1032f..1e4710d 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -131,6 +131,18 @@ static int vhost_net_get_fd(NetClientState *backend)
     }
 }
 
+static void vhost_net_backend_stop(struct vhost_dev *dev)
+{
+    struct vhost_net *net = container_of(dev, struct vhost_net, dev);
+    NetClientState *nc = net->nc;
+    NetClientState *peer = nc->peer;
+
+    peer->link_down = 1;
+    if (peer->info->link_status_changed) {
+        peer->info->link_status_changed(peer);
+    }
+}
+
 struct vhost_net *vhost_net_init(VhostNetOptions *options)
 {
     int r;
@@ -165,6 +177,8 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options)
         net->dev.vq_index = net->nc->queue_index * net->dev.nvqs;
     }
 
+    net->dev.stop = vhost_net_backend_stop;
+
     r = vhost_dev_init(&net->dev, options->opaque,
                        options->backend_type);
     if (r < 0) {
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index b60d758..859be64 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -35,6 +35,8 @@ struct vhost_log {
     vhost_log_chunk_t *log;
 };
 
+typedef void (*vhost_stop)(struct vhost_dev *dev);
+
 struct vhost_memory;
 struct vhost_dev {
     MemoryListener memory_listener;
@@ -61,6 +63,8 @@ struct vhost_dev {
     void *opaque;
     struct vhost_log *log;
     QLIST_ENTRY(vhost_dev) entry;
+    /* backend request to stop */
+    vhost_stop stop;
 };
 
 int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
-- 
2.5.5