From bcabc70abb16c3a821d9bf449203be582b04307b Mon Sep 17 00:00:00 2001 From: Jiayu Hu <jiayu.hu@intel.com> Date: Tue, 20 Apr 2021 04:57:46 -0400 Subject: [PATCH] doc: update async vhost register/unregister This patch is to update programmer guide for register/unregister copy devices in vhost. Signed-off-by: Jiayu Hu <jiayu.hu@intel.com> Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> --- doc/guides/prog_guide/vhost_lib.rst | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst index dc29229167..7afa351675 100644 --- a/doc/guides/prog_guide/vhost_lib.rst +++ b/doc/guides/prog_guide/vhost_lib.rst @@ -208,9 +208,9 @@ The following is an overview of some key Vhost API functions: * ``rte_vhost_async_channel_register(vid, queue_id, features, ops)`` - Register a vhost queue with async copy device channel. - Following device ``features`` must be specified together with the - registration: + Register a vhost queue with async copy device channel after vring + is enabled. Following device ``features`` must be specified together + with the registration: * ``async_inorder`` @@ -244,6 +244,14 @@ The following is an overview of some key Vhost API functions: * ``rte_vhost_async_channel_unregister(vid, queue_id)`` Unregister the async copy device channel from a vhost queue. + Unregistration will fail, if the vhost queue has in-flight + packets that are not completed. + + Unregister async copy devices in vring_state_changed() may + fail, as this API tries to acquire the spinlock of vhost + queue. The recommended way is to unregister async copy + devices for all vhost queues in destroy_device(), when a + virtio device is paused or shut down. * ``rte_vhost_submit_enqueue_burst(vid, queue_id, pkts, count, comp_pkts, comp_count)``