Re: [dpdk-dev] [PATCH] vhost: added user callbacks for socket open/close

[Jens Freimann <jfreimann@redhat.com>]

Hi Dariusz,

On Mon, Aug 21, 2017 at 11:34:42AM +0200, Dariusz Stojaczyk wrote:
>When user receives destroy_device signal, he does not know *why* that
>event happened. He does not differ between socket shutdown and virtio
>processing pause. User could completely delete device during transition
>from BIOS to kernel, causing freeze or possibly kernel panic. Instead
>of changing new_device/destroy_device callbacks and breaking the ABI,
>a set of new functions new_connection/destroy_connection has been added.
>
>Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
>---
> lib/librte_vhost/rte_vhost.h |  5 ++++-
> lib/librte_vhost/socket.c    | 23 +++++++++++++++++++----
> 2 files changed, 23 insertions(+), 5 deletions(-)
>
>diff --git a/lib/librte_vhost/rte_vhost.h b/lib/librte_vhost/rte_vhost.h
>index 8c974eb..8f86167 100644
>--- a/lib/librte_vhost/rte_vhost.h
>+++ b/lib/librte_vhost/rte_vhost.h
>@@ -107,7 +107,10 @@ struct vhost_device_ops {
> 	 */
> 	int (*features_changed)(int vid, uint64_t features);
>
>-	void *reserved[4]; /**< Reserved for future extension */
>+	int (*new_connection)(int vid);		/**< Connect to socket. */
>+	void (*destroy_connection)(int vid);	/**< Disconnect from socket */

I'm a little uncertain but my gut feeling is that in this context a connection is
something between two sockets, not between devices. I would probably
add these callbacks to struct vhost_user_socket. This is also where we
keep the list of connections.

regards,
Jens