[Qemu-devel] [RFC 3/5] vhost_net: send virtio device status update to the backend

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch adds ans uses a new function to send virtio device
status updates to the backend.

Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 hw/net/vhost_net.c      | 10 ++++++++++
 hw/net/virtio-net.c     |  7 ++++++-
 include/net/vhost_net.h |  2 ++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index e037db63a3..75e2165163 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -450,6 +450,11 @@ int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
     return vhost_ops->vhost_net_set_mtu(&net->dev, mtu);
 }
 
+int vhost_net_set_virtio_status(struct vhost_net *net, uint8_t status)
+{
+    return vhost_dev_set_virtio_status(&net->dev, status);
+}
+
 #else
 uint64_t vhost_net_get_max_queues(VHostNetState *net)
 {
@@ -521,4 +526,9 @@ int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu)
 {
     return 0;
 }
+
+int vhost_net_set_virtio_status(struct vhost_net *net, uint8_t status)
+{
+    return 0;
+}
 #endif
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 38674b08aa..06c431ea28 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -136,7 +136,7 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
 
     if ((virtio_net_started(n, status) && !nc->peer->link_down) ==
         !!n->vhost_started) {
-        return;
+        goto out;
     }
     if (!n->vhost_started) {
         int r, i;
@@ -175,11 +175,16 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
             error_report("unable to start vhost net: %d: "
                          "falling back on userspace virtio", -r);
             n->vhost_started = 0;
+
+            return;
         }
     } else {
         vhost_net_stop(vdev, n->nic->ncs, queues);
         n->vhost_started = 0;
     }
+
+out:
+    vhost_net_set_virtio_status(get_vhost_net(nc->peer), status);
 }
 
 static int virtio_net_set_vnet_endian_one(VirtIODevice *vdev,
diff --git a/include/net/vhost_net.h b/include/net/vhost_net.h
index afc1499eb9..bf083e2d2e 100644
--- a/include/net/vhost_net.h
+++ b/include/net/vhost_net.h
@@ -37,4 +37,6 @@ uint64_t vhost_net_get_acked_features(VHostNetState *net);
 
 int vhost_net_set_mtu(struct vhost_net *net, uint16_t mtu);
 
+int vhost_net_set_virtio_status(struct vhost_net *net, uint8_t status);
+
 #endif
-- 
2.14.3