vhost: Add stubs for the migration state transfer interface
Migration state transfer interface is only used by vhost-user-fs,
so the interface needs to be defined only when vhost is built.
But I need to use this interface with virtio-net and vhost is not always
enabled, and to avoid undefined reference error during build, define stub
functions for vhost_supports_device_state(), vhost_save_backend_state() and
vhost_load_backend_state().
Cc: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Message-Id: <20250115135044.799698-2-lvivier@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 461c168..a9469d5 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -365,7 +365,14 @@
* Returns true if the device supports these commands, and false if it
* does not.
*/
+#ifdef CONFIG_VHOST
bool vhost_supports_device_state(struct vhost_dev *dev);
+#else
+static inline bool vhost_supports_device_state(struct vhost_dev *dev)
+{
+ return false;
+}
+#endif
/**
* vhost_set_device_state_fd(): Begin transfer of internal state from/to
@@ -448,7 +455,15 @@
*
* Returns 0 on success, and -errno otherwise.
*/
+#ifdef CONFIG_VHOST
int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp);
+#else
+static inline int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f,
+ Error **errp)
+{
+ return -ENOSYS;
+}
+#endif
/**
* vhost_load_backend_state(): High-level function to load a vhost
@@ -465,6 +480,14 @@
*
* Returns 0 on success, and -errno otherwise.
*/
+#ifdef CONFIG_VHOST
int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp);
+#else
+static inline int vhost_load_backend_state(struct vhost_dev *dev, QEMUFile *f,
+ Error **errp)
+{
+ return -ENOSYS;
+}
+#endif
#endif
