hw/virtio/vhost.h

358  * vhost_supports_device_state(): Checks whether the back-end supports
372  * the back-end for the purpose of migration.  Data is to be transferred
378  * @fd is the back-end's end of the pipe: The write FD for SAVE, and the
380  * back-end, i.e. closes it in the front-end.
382  * The back-end may optionally reply with an FD of its own, if this
384  * stored in *reply_fd.  The back-end will discard the FD sent to it,
386  * the back-end.
391  *             from the back-end and stored by the front-end in the
395  *             the back-end to restore the saved state.
399  * @fd: Back-end's end of the pipe through which to transfer state; note
400  *      that ownership is transferred to the back-end, so this function
402  * @reply_fd: If the back-end wishes to use a different pipe for state
418  * back-end via vhost_set_device_state_fd(), i.e. once the sending end
419  * has closed the pipe, inquire the back-end to report any potential
425  *   invalid and cannot be processed by the back-end
430  * Returns 0 when the back-end reports successful state transfer and
437  * back-end's state, and save it in @f.  Uses
438  * `vhost_set_device_state_fd()` to get the data from the back-end, and
455  * back-end's state from @f, and send it over to the back-end.  Reads
457  * `vhost_set_device_state_fd()` to transfer it to the back-end.