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, 3 insertions, 0 deletions

diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index ad1948101d..c59cc81915 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -68,6 +68,8 @@ typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
 typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
                                          int enable);
 typedef bool (*vhost_requires_shm_log_op)(struct vhost_dev *dev);
+typedef int (*vhost_migration_done_op)(struct vhost_dev *dev,
+                                       char *mac_addr);
 
 typedef struct VhostOps {
     VhostBackendType backend_type;
@@ -94,6 +96,7 @@ typedef struct VhostOps {
     vhost_get_vq_index_op vhost_get_vq_index;
     vhost_set_vring_enable_op vhost_set_vring_enable;
     vhost_requires_shm_log_op vhost_requires_shm_log;
+    vhost_migration_done_op vhost_migration_done;
 } VhostOps;
 
 extern const VhostOps user_ops;