librdmacm/cma: provide sanity checks for max outstanding rdma ops

Ensure that the responder_resources and initiator_depth values
provided by the user are supported by the local hardware.  This
traps errors sooner during connection establishment (when calling
rdma_connect), rather than waiting until the modify QP fails
(after calling rdma_accept).

Signed-off-by: Sean Hefty <sean.hefty@intel.com>

diff --git a/src/cma.c b/src/cma.c
index c0ae114e17809b8a051eb1eb08362abaf89ad462..00ea394d0e103755bf8e374108d4c6ba88a7c076 100644 (file)
--- a/src/cma.c
+++ b/src/cma.c
@@ -116,6 +116,8 @@ struct cma_device {
        struct ibv_context *verbs;
        uint64_t            guid;
        int                 port_cnt;
+       uint8_t             max_initiator_depth;
+       uint8_t             max_responder_resources;
 };
 
 struct cma_id_private {
@@ -246,6 +248,8 @@ static int ucma_init(void)
                }
 
                cma_dev->port_cnt = attr.phys_port_cnt;
+               cma_dev->max_initiator_depth = (uint8_t) attr.max_qp_init_rd_atom;
+               cma_dev->max_responder_resources = (uint8_t) attr.max_qp_rd_atom;
        }
 out:
        pthread_mutex_unlock(&mut);
@@ -810,6 +814,21 @@ void rdma_destroy_qp(struct rdma_cm_id *id)
        ibv_destroy_qp(id->qp);
 }
 
+static int ucma_valid_param(struct cma_id_private *id_priv,
+                           struct rdma_conn_param *conn_param)
+{
+       if (id_priv->id.ps != RDMA_PS_TCP)
+               return 0;
+
+       if ((conn_param->responder_resources >
+            id_priv->cma_dev->max_responder_resources) ||
+           (conn_param->initiator_depth >
+            id_priv->cma_dev->max_initiator_depth))
+               return -EINVAL;
+
+       return 0;
+}
+
 static void ucma_copy_conn_param_to_kern(struct ucma_abi_conn_param *dst,
                                         struct rdma_conn_param *src,
                                         uint32_t qp_num, uint8_t srq)
@@ -837,8 +856,12 @@ int rdma_connect(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
        void *msg;
        int ret, size;
        
-       CMA_CREATE_MSG_CMD(msg, cmd, UCMA_CMD_CONNECT, size);
        id_priv = container_of(id, struct cma_id_private, id);
+       ret = ucma_valid_param(id_priv, conn_param);
+       if (ret)
+               return ret;
+
+       CMA_CREATE_MSG_CMD(msg, cmd, UCMA_CMD_CONNECT, size);
        cmd->id = id_priv->handle;
        if (id->qp)
                ucma_copy_conn_param_to_kern(&cmd->conn_param, conn_param,
@@ -882,6 +905,11 @@ int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
        void *msg;
        int ret, size;
 
+       id_priv = container_of(id, struct cma_id_private, id);
+       ret = ucma_valid_param(id_priv, conn_param);
+       if (ret)
+               return ret;
+
        if (!ucma_is_ud_ps(id->ps)) {
                ret = ucma_modify_qp_rtr(id);
                if (ret)
@@ -889,7 +917,6 @@ int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
        }
 
        CMA_CREATE_MSG_CMD(msg, cmd, UCMA_CMD_ACCEPT, size);
-       id_priv = container_of(id, struct cma_id_private, id);
        cmd->id = id_priv->handle;
        cmd->uid = (uintptr_t) id_priv;
        if (id->qp)