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>
This commit is contained in:
Laurent Vivier 2025-01-15 14:50:43 +01:00 committed by Michael S. Tsirkin
parent 1ce979e726
commit 3f65357313

View file

@ -365,7 +365,14 @@ static inline int vhost_reset_device(struct vhost_dev *hdev)
* 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 @@ int vhost_check_device_state(struct vhost_dev *dev, Error **errp);
*
* 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 @@ int vhost_save_backend_state(struct vhost_dev *dev, QEMUFile *f, Error **errp);
*
* 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