RDMA/rxe: Fix mismatched max_msg_sz

User mode queries max_msg_sz as 0x800000 by command 'ibv_devinfo -v',
however ibv_post_send/ibv_post_recv has a limit of 2^31. Fix this
mismatched information.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Fixes: f605f26 ("RDMA/rxe: Protect QP state with qp->state_lock")
Fixes: 5bf944f ("RDMA/rxe: Add error messages")
Link: https://patch.msgid.link/20241216121953.765331-1-pizhenwei@bytedance.com
Review-by: Zhu Yanjun <yanjun.zhu@linux.dev>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: pizhenwei

drivers/infiniband/sw/rxe/rxe_param.h

@@ -129,7 +129,7 @@ enum rxe_device_param {
 enum rxe_port_param {
 	RXE_PORT_GID_TBL_LEN		= 1024,
 	RXE_PORT_PORT_CAP_FLAGS		= IB_PORT_CM_SUP,
-	RXE_PORT_MAX_MSG_SZ		= 0x800000,
+	RXE_PORT_MAX_MSG_SZ		= (1UL << 31),
 	RXE_PORT_BAD_PKEY_CNTR		= 0,
 	RXE_PORT_QKEY_VIOL_CNTR		= 0,
 	RXE_PORT_LID			= 0,

drivers/infiniband/sw/rxe/rxe_verbs.c

@@ -688,7 +688,7 @@ static int validate_send_wr(struct rxe_qp *qp, const struct ib_send_wr *ibwr,
 		for (i = 0; i < ibwr->num_sge; i++)
 			length += ibwr->sg_list[i].length;
 
-		if (length > (1UL << 31)) {
+		if (length > RXE_PORT_MAX_MSG_SZ) {
 			rxe_err_qp(qp, "message length too long\n");
 			break;
 		}
@@ -972,8 +972,7 @@ static int post_one_recv(struct rxe_rq *rq, const struct ib_recv_wr *ibwr)
 	for (i = 0; i < num_sge; i++)
 		length += ibwr->sg_list[i].length;
 
-	/* IBA max message size is 2^31 */
-	if (length >= (1UL<<31)) {
+	if (length > RXE_PORT_MAX_MSG_SZ) {
 		err = -EINVAL;
 		rxe_dbg("message length too long\n");
 		goto err_out;