hw/virtio/vhost.h

101      * @acked_features: final negotiated features with front-end driver
360  * vhost_supports_device_state(): Checks whether the back-end supports
381  * the back-end for the purpose of migration.  Data is to be transferred
382  * over a pipe according to @direction and @phase.  The sending end must
383  * only write to the pipe, and the receiving end must only read from it.
384  * Once the sending end is done, it closes its FD.  The receiving end
385  * must take this as the end-of-transfer signal and close its FD, too.
387  * @fd is the back-end's end of the pipe: The write FD for SAVE, and the
389  * back-end, i.e. closes it in the front-end.
391  * The back-end may optionally reply with an FD of its own, if this
392  * improves efficiency on its end.  In this case, the returned FD is
393  * stored in *reply_fd.  The back-end will discard the FD sent to it,
394  * and the front-end must use *reply_fd for transferring state to/from
395  * the back-end.
400  *             from the back-end and stored by the front-end in the
403  *             by the front-end from the migration stream and sent to
404  *             the back-end to restore the saved state.
408  * @fd: Back-end's end of the pipe through which to transfer state; note
409  *      that ownership is transferred to the back-end, so this function
410  *      closes @fd in the front-end.
411  * @reply_fd: If the back-end wishes to use a different pipe for state
412  *            transfer, this will contain an FD for the front-end to
427  * back-end via vhost_set_device_state_fd(), i.e. once the sending end
428  * has closed the pipe, inquire the back-end to report any potential
434  *   invalid and cannot be processed by the back-end
439  * Returns 0 when the back-end reports successful state transfer and
446  * back-end's state, and save it in @f.  Uses
447  * `vhost_set_device_state_fd()` to get the data from the back-end, and
449  * respective length (be32).  The end is marked by a 0-length chunk.
472  * back-end's state from @f, and send it over to the back-end.  Reads
474  * `vhost_set_device_state_fd()` to transfer it to the back-end.