[openib-general] [RFC] [PATCH] rdma/ib_cm: fix APM support

Sean Hefty sean.hefty at intel.com
Tue Oct 31 16:25:48 PST 2006


The following patch attempts to fix issues in the ib_cm regarding support
for path migration.  The fixes are mainly on feedback from Venkatesh.
The patch has NOT been tested to verify that APM works correctly, but I did
check that it didn't break anything.  I need to develop a test program to
verify that APM works.

I'd like to get feedback to this approach.  For the most part, it makes
use of the existing interfaces where possible to limit changes to the 
userspace library.  More specifically:

The ib_cm_establish() call is replaced with a more generic ib_cm_notify().
This routine is used to notify the CM that failover has occurred, so that
future CM messages (LAP, DREQ) reach the remote CM.

New alternate path information is captured when a LAP message is sent or
received.  This allows QP attributes to be initialized for the user
when loading a new path after failover has occurred.

Signed-off-by: Sean Hefty <sean.hefty at intel.com>
---
Venkatesh / anyone else: it would be helpful if someone could try porting
their application to this interface, and let me know if it works.  I'm
working on a test program for this, but it will take a few days to create
it.

diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 1cf0d42..c4e9bb5 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -152,7 +152,6 @@ struct cm_id_private {
 	u8 peer_to_peer;
 	u8 responder_resources;
 	u8 initiator_depth;
-	u8 local_ack_timeout;
 	u8 retry_count;
 	u8 rnr_retry_count;
 	u8 service_timeout;
@@ -691,7 +690,7 @@ static void cm_enter_timewait(struct cm_
 	 * timewait before notifying the user that we've exited timewait.
 	 */
 	cm_id_priv->id.state = IB_CM_TIMEWAIT;
-	wait_time = cm_convert_to_ms(cm_id_priv->local_ack_timeout);
+	wait_time = cm_convert_to_ms(cm_id_priv->av.packet_life_time + 1);
 	queue_delayed_work(cm.wq, &cm_id_priv->timewait_info->work.work,
 			   msecs_to_jiffies(wait_time));
 	cm_id_priv->timewait_info = NULL;
@@ -1024,8 +1023,6 @@ int ib_send_cm_req(struct ib_cm_id *cm_i
 
 	cm_id_priv->local_qpn = cm_req_get_local_qpn(req_msg);
 	cm_id_priv->rq_psn = cm_req_get_starting_psn(req_msg);
-	cm_id_priv->local_ack_timeout =
-				cm_req_get_primary_local_ack_timeout(req_msg);
 
 	spin_lock_irqsave(&cm_id_priv->lock, flags);
 	ret = ib_post_send_mad(cm_id_priv->msg, NULL);
@@ -1411,8 +1408,6 @@ static int cm_req_handler(struct cm_work
 	cm_id_priv->responder_resources = cm_req_get_init_depth(req_msg);
 	cm_id_priv->path_mtu = cm_req_get_path_mtu(req_msg);
 	cm_id_priv->sq_psn = cm_req_get_starting_psn(req_msg);
-	cm_id_priv->local_ack_timeout =
-				cm_req_get_primary_local_ack_timeout(req_msg);
 	cm_id_priv->retry_count = cm_req_get_retry_count(req_msg);
 	cm_id_priv->rnr_retry_count = cm_req_get_rnr_retry_count(req_msg);
 	cm_id_priv->qp_type = cm_req_get_qp_type(req_msg);
@@ -1716,7 +1711,7 @@ static int cm_establish_handler(struct c
 	unsigned long flags;
 	int ret;
 
-	/* See comment in ib_cm_establish about lookup. */
+	/* See comment in cm_establish about lookup. */
 	cm_id_priv = cm_acquire_id(work->local_id, work->remote_id);
 	if (!cm_id_priv)
 		return -EINVAL;
@@ -2402,11 +2397,16 @@ int ib_send_cm_lap(struct ib_cm_id *cm_i
 	cm_id_priv = container_of(cm_id, struct cm_id_private, id);
 	spin_lock_irqsave(&cm_id_priv->lock, flags);
 	if (cm_id->state != IB_CM_ESTABLISHED ||
-	    cm_id->lap_state != IB_CM_LAP_IDLE) {
+	    (cm_id->lap_state != IB_CM_LAP_UNINIT &&
+	     cm_id->lap_state != IB_CM_LAP_IDLE)) {
 		ret = -EINVAL;
 		goto out;
 	}
 
+	ret = cm_init_av_by_path(alternate_path, &cm_id_priv->alt_av);
+	if (ret)
+		goto out;
+
 	ret = cm_alloc_msg(cm_id_priv, &msg);
 	if (ret)
 		goto out;
@@ -2480,6 +2480,7 @@ static int cm_lap_handler(struct cm_work
 		goto unlock;
 
 	switch (cm_id_priv->id.lap_state) {
+	case IB_CM_LAP_UNINIT:
 	case IB_CM_LAP_IDLE:
 		break;
 	case IB_CM_MRA_LAP_SENT:
@@ -2502,6 +2503,10 @@ static int cm_lap_handler(struct cm_work
 
 	cm_id_priv->id.lap_state = IB_CM_LAP_RCVD;
 	cm_id_priv->tid = lap_msg->hdr.tid;
+	cm_init_av_for_response(work->port, work->mad_recv_wc->wc,
+				work->mad_recv_wc->recv_buf.grh,
+				&cm_id_priv->av);
+	cm_init_av_by_path(param->alternate_path, &cm_id_priv->alt_av);
 	ret = atomic_inc_and_test(&cm_id_priv->work_count);
 	if (!ret)
 		list_add_tail(&work->list, &cm_id_priv->work_list);
@@ -3040,7 +3045,7 @@ static void cm_work_handler(void *data)
 		cm_free_work(work);
 }
 
-int ib_cm_establish(struct ib_cm_id *cm_id)
+static int cm_establish(struct ib_cm_id *cm_id)
 {
 	struct cm_id_private *cm_id_priv;
 	struct cm_work *work;
@@ -3088,7 +3093,43 @@ int ib_cm_establish(struct ib_cm_id *cm_
 out:
 	return ret;
 }
-EXPORT_SYMBOL(ib_cm_establish);
+
+static int cm_migrate(struct ib_cm_id *cm_id)
+{
+	struct cm_id_private *cm_id_priv;
+	unsigned long flags;
+	int ret = 0;
+
+	cm_id_priv = container_of(cm_id, struct cm_id_private, id);
+	spin_lock_irqsave(&cm_id_priv->lock, flags);
+	if (cm_id->state == IB_CM_ESTABLISHED &&
+	    (cm_id->lap_state == IB_CM_LAP_UNINIT ||
+	     cm_id->lap_state == IB_CM_LAP_IDLE))
+		cm_id_priv->av = cm_id_priv->alt_av;
+	else
+		ret = -EINVAL;
+	spin_unlock_irqrestore(&cm_id_priv->lock, flags);
+
+	return ret;
+}
+
+int ib_cm_notify(struct ib_cm_id *cm_id, enum ib_event_type event)
+{
+	int ret;
+
+	switch (event) {
+	case IB_EVENT_COMM_EST:
+		ret = cm_establish(cm_id);
+		break;
+	case IB_EVENT_PATH_MIG:
+		ret = cm_migrate(cm_id);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	return ret;
+}
+EXPORT_SYMBOL(ib_cm_notify);
 
 static void cm_recv_handler(struct ib_mad_agent *mad_agent,
 			    struct ib_mad_recv_wc *mad_recv_wc)
@@ -3221,6 +3262,9 @@ static int cm_init_qp_rtr_attr(struct cm
 		if (cm_id_priv->alt_av.ah_attr.dlid) {
 			*qp_attr_mask |= IB_QP_ALT_PATH;
 			qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
+			qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
+			qp_attr->alt_timeout =
+					cm_id_priv->alt_av.packet_life_time + 1;
 			qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
 		}
 		ret = 0;
@@ -3247,19 +3291,31 @@ static int cm_init_qp_rts_attr(struct cm
 	case IB_CM_REP_SENT:
 	case IB_CM_MRA_REP_RCVD:
 	case IB_CM_ESTABLISHED:
-		*qp_attr_mask = IB_QP_STATE | IB_QP_SQ_PSN;
-		qp_attr->sq_psn = be32_to_cpu(cm_id_priv->sq_psn);
-		if (cm_id_priv->qp_type == IB_QPT_RC) {
-			*qp_attr_mask |= IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
-					 IB_QP_RNR_RETRY |
-					 IB_QP_MAX_QP_RD_ATOMIC;
-			qp_attr->timeout = cm_id_priv->local_ack_timeout;
-			qp_attr->retry_cnt = cm_id_priv->retry_count;
-			qp_attr->rnr_retry = cm_id_priv->rnr_retry_count;
-			qp_attr->max_rd_atomic = cm_id_priv->initiator_depth;
-		}
-		if (cm_id_priv->alt_av.ah_attr.dlid) {
-			*qp_attr_mask |= IB_QP_PATH_MIG_STATE;
+		if (cm_id_priv->id.lap_state == IB_CM_LAP_UNINIT) {
+			*qp_attr_mask = IB_QP_STATE | IB_QP_SQ_PSN;
+			qp_attr->sq_psn = be32_to_cpu(cm_id_priv->sq_psn);
+			if (cm_id_priv->qp_type == IB_QPT_RC) {
+				*qp_attr_mask |= IB_QP_TIMEOUT | IB_QP_RETRY_CNT |
+						 IB_QP_RNR_RETRY |
+						 IB_QP_MAX_QP_RD_ATOMIC;
+				qp_attr->timeout =
+					cm_id_priv->av.packet_life_time + 1;
+				qp_attr->retry_cnt = cm_id_priv->retry_count;
+				qp_attr->rnr_retry = cm_id_priv->rnr_retry_count;
+				qp_attr->max_rd_atomic =
+					cm_id_priv->initiator_depth;
+			}
+			if (cm_id_priv->alt_av.ah_attr.dlid) {
+				*qp_attr_mask |= IB_QP_PATH_MIG_STATE;
+				qp_attr->path_mig_state = IB_MIG_REARM;
+			}
+		} else {
+			*qp_attr_mask = IB_QP_ALT_PATH | IB_QP_PATH_MIG_STATE;
+			qp_attr->alt_port_num = cm_id_priv->alt_av.port->port_num;
+			qp_attr->alt_pkey_index = cm_id_priv->alt_av.pkey_index;
+			qp_attr->alt_timeout =
+				cm_id_priv->alt_av.packet_life_time + 1;
+			qp_attr->alt_ah_attr = cm_id_priv->alt_av.ah_attr;
 			qp_attr->path_mig_state = IB_MIG_REARM;
 		}
 		ret = 0;
diff --git a/drivers/infiniband/core/ucm.c b/drivers/infiniband/core/ucm.c
index ad4f4d5..e04f662 100644
--- a/drivers/infiniband/core/ucm.c
+++ b/drivers/infiniband/core/ucm.c
@@ -685,11 +685,11 @@ out:
 	return result;
 }
 
-static ssize_t ib_ucm_establish(struct ib_ucm_file *file,
-				const char __user *inbuf,
-				int in_len, int out_len)
+static ssize_t ib_ucm_notify(struct ib_ucm_file *file,
+			     const char __user *inbuf,
+			     int in_len, int out_len)
 {
-	struct ib_ucm_establish cmd;
+	struct ib_ucm_notify cmd;
 	struct ib_ucm_context *ctx;
 	int result;
 
@@ -700,7 +700,7 @@ static ssize_t ib_ucm_establish(struct i
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
-	result = ib_cm_establish(ctx->cm_id);
+	result = ib_cm_notify(ctx->cm_id, (enum ib_event_type) cmd.event);
 	ib_ucm_ctx_put(ctx);
 	return result;
 }
@@ -1107,7 +1107,7 @@ static ssize_t (*ucm_cmd_table[])(struct
 	[IB_USER_CM_CMD_DESTROY_ID]    = ib_ucm_destroy_id,
 	[IB_USER_CM_CMD_ATTR_ID]       = ib_ucm_attr_id,
 	[IB_USER_CM_CMD_LISTEN]        = ib_ucm_listen,
-	[IB_USER_CM_CMD_ESTABLISH]     = ib_ucm_establish,
+	[IB_USER_CM_CMD_NOTIFY]        = ib_ucm_notify,
 	[IB_USER_CM_CMD_SEND_REQ]      = ib_ucm_send_req,
 	[IB_USER_CM_CMD_SEND_REP]      = ib_ucm_send_rep,
 	[IB_USER_CM_CMD_SEND_RTU]      = ib_ucm_send_rtu,
diff --git a/include/rdma/ib_cm.h b/include/rdma/ib_cm.h
index c9b4738..5c07017 100644
--- a/include/rdma/ib_cm.h
+++ b/include/rdma/ib_cm.h
@@ -60,6 +60,7 @@ enum ib_cm_state {
 };
 
 enum ib_cm_lap_state {
+	IB_CM_LAP_UNINIT,
 	IB_CM_LAP_IDLE,
 	IB_CM_LAP_SENT,
 	IB_CM_LAP_RCVD,
@@ -443,13 +444,20 @@ int ib_send_cm_drep(struct ib_cm_id *cm_
 		    u8 private_data_len);
 
 /**
- * ib_cm_establish - Forces a connection state to established.
+ * ib_cm_notify - Notifies the CM of an event reported to the consumer.
  * @cm_id: Connection identifier to transition to established.
+ * @event: Type of event.
  *
- * This routine should be invoked by users who receive messages on a
- * connected QP before an RTU has been received.
+ * This routine should be invoked by users to notify the CM of relevant
+ * communication events.  Events that should be reported to the CM and
+ * when to report them are:
+ *
+ * IB_EVENT_COMM_EST - Used when a message is received on a connected
+ *    QP before an RTU has been received.
+ * IB_EVENT_PATH_MIG - Notifies the CM that the connection has failed over
+ *   to the alternate path.
  */
-int ib_cm_establish(struct ib_cm_id *cm_id);
+int ib_cm_notify(struct ib_cm_id *cm_id, enum ib_event_type event);
 
 /**
  * ib_send_cm_rej - Sends a connection rejection message to the
diff --git a/include/rdma/ib_user_cm.h b/include/rdma/ib_user_cm.h
old mode 100644
new mode 100755
index 066c20b..37650af
--- a/include/rdma/ib_user_cm.h
+++ b/include/rdma/ib_user_cm.h
@@ -38,7 +38,7 @@ #define IB_USER_CM_H
 
 #include <rdma/ib_user_sa.h>
 
-#define IB_USER_CM_ABI_VERSION 4
+#define IB_USER_CM_ABI_VERSION 5
 
 enum {
 	IB_USER_CM_CMD_CREATE_ID,
@@ -46,7 +46,7 @@ enum {
 	IB_USER_CM_CMD_ATTR_ID,
 
 	IB_USER_CM_CMD_LISTEN,
-	IB_USER_CM_CMD_ESTABLISH,
+	IB_USER_CM_CMD_NOTIFY,
 
 	IB_USER_CM_CMD_SEND_REQ,
 	IB_USER_CM_CMD_SEND_REP,
@@ -117,8 +117,9 @@ struct ib_ucm_listen {
 	__u32 reserved;
 };
 
-struct ib_ucm_establish {
+struct ib_ucm_notify {
 	__u32 id;
+	__u32 event;
 };
 
 struct ib_ucm_private_data {





More information about the general mailing list