vhost user: add rarp sending after live migration for legacy guest

A new vhost user message is added to allow QEMU to ask to vhost user backend to
broadcast a fake RARP after live migration for guest without GUEST_ANNOUNCE
capability.

This new message is sent only if the backend supports the new
VHOST_USER_PROTOCOL_F_RARP protocol feature.
The payload of this new message is the MAC address of the guest (not known by
the backend). The MAC address is copied in the first 6 bytes of a u64 to avoid
to create a new payload message type.

This new message has no equivalent ioctl so a new callback is added in the
userOps structure to send the request.

Upon reception of this new message the vhost user backend must generate and
broadcast a fake RARP request to notify the migration is terminated.

Signed-off-by: Thibaut Collet <thibaut.collet@6wind.com>
[Rebased and fixed checkpatch errors - Marc-André]
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Thibaut Collet <thibaut.collet@6wind.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 840f443..d91b7b1 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -388,6 +388,18 @@ void vhost_net_cleanup(struct vhost_net *net)
     g_free(net);
 }
 
+int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
+{
+    const VhostOps *vhost_ops = net->dev.vhost_ops;
+    int r = -1;
+
+    if (vhost_ops->vhost_migration_done) {
+        r = vhost_ops->vhost_migration_done(&net->dev, mac_addr);
+    }
+
+    return r;
+}
+
 bool vhost_net_virtqueue_pending(VHostNetState *net, int idx)
 {
     return vhost_virtqueue_pending(&net->dev, idx);
@@ -479,6 +491,11 @@ void vhost_net_virtqueue_mask(VHostNetState *net, VirtIODevice *dev,
 {
 }
 
+int vhost_net_notify_migration_done(struct vhost_net *net, char* mac_addr)
+{
+    return -1;
+}
+
 VHostNetState *get_vhost_net(NetClientState *nc)
 {
     return 0;