RDMA/ucma: Deliver ECE parameters through UCMA events

Passive side of CMID connection receives ECE request through REQ message
and needs to respond with relevant REP message which will be forwarded to
active side.

The UCMA events interface is responsible for such communication with the
user space (librdmacm). Extend it to provide ECE wire data.

Link: https://lore.kernel.org/r/20200526103304.196371-4-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/core/ucma.c

@@ -360,6 +360,9 @@ static int ucma_event_handler(struct rdma_cm_id *cm_id,
 		ucma_copy_conn_event(&uevent->resp.param.conn,
 				     &event->param.conn);
 
+	uevent->resp.ece.vendor_id = event->ece.vendor_id;
+	uevent->resp.ece.attr_mod = event->ece.attr_mod;
+
 	if (event->event == RDMA_CM_EVENT_CONNECT_REQUEST) {
 		if (!ctx->backlog) {
 			ret = -ENOMEM;
@@ -404,7 +407,8 @@ static ssize_t ucma_get_event(struct ucma_file *file, const char __user *inbuf,
 	 * Old 32 bit user space does not send the 4 byte padding in the
 	 * reserved field. We don't care, allow it to keep working.
 	 */
-	if (out_len < sizeof(uevent->resp) - sizeof(uevent->resp.reserved))
+	if (out_len < sizeof(uevent->resp) - sizeof(uevent->resp.reserved) -
+			      sizeof(uevent->resp.ece))
 		return -ENOSPC;
 
 	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))

include/rdma/rdma_cm.h

@@ -111,6 +111,7 @@ struct rdma_cm_event {
 		struct rdma_conn_param	conn;
 		struct rdma_ud_param	ud;
 	} param;
+	struct rdma_ucm_ece ece;
 };
 
 struct rdma_cm_id;

include/uapi/rdma/rdma_user_cm.h

@@ -297,6 +297,7 @@ struct rdma_ucm_event_resp {
 		struct rdma_ucm_ud_param   ud;
 	} param;
 	__u32 reserved;
+	struct rdma_ucm_ece ece;
 };
 
 /* Option levels */