nvmf: Limit the default I/O queue size to 128 entries

Previously the size defaulted to the maximum supported size reported
by the remote host.  The value of 128 matches the default on Linux and
avoids excessive resource usage for I/O queues.

Sponsored by:	Chelsio Communications

sbin/nvmecontrol/fabrics.c

@@ -485,7 +485,7 @@ connect_nvm_queues(const struct nvmf_association_params *aparams,
 	/* Validate I/O queue size. */
 	memset(io, 0, sizeof(*io) * num_io_queues);
 	if (queue_size == 0)
-		queue_size = (u_int)mqes + 1;
+		queue_size = MIN(NVMF_DEFAULT_IO_ENTRIES, (u_int)mqes + 1);
 	else if (queue_size > (u_int)mqes + 1) {
 		warnx("I/O queue size exceeds controller maximum (%u)",
 		    mqes + 1);

sbin/nvmecontrol/nvmecontrol.8

@@ -33,7 +33,7 @@
 .\"
 .\" Author: Jim Harris <jimharris@FreeBSD.org>
 .\"
-.Dd January 31, 2026
+.Dd February 20, 2026
 .Dt NVMECONTROL 8
 .Os
 .Sh NAME
@@ -828,8 +828,8 @@ NVMe Qualified Name to use for this host.
 By default an NQN is auto-generated from the current host's UUID.
 .It Fl Q Ar entries
 Number of entries in each I/O queue.
-By default the maximum queue size reported by the MQES field
-of the remote host's CAP property is used.
+The default is the minimum of 128 or the maximum queue size reported
+by the MQES field of the remote host's CAP property.
 .El
 .Ss connect-all
 Query the Discovery Controller at

sys/dev/nvmf/nvmf.h

@@ -27,11 +27,12 @@
 #define	NVMF_NN			(1024)
 
 /*
- * Default timeouts for Fabrics hosts.  These match values used by
+ * Default settings for Fabrics hosts.  These match values used by
  * Linux.
  */
 #define	NVMF_DEFAULT_RECONNECT_DELAY	10
 #define	NVMF_DEFAULT_CONTROLLER_LOSS	600
+#define	NVMF_DEFAULT_IO_ENTRIES		128
 
 /*
  * (data, size) is the userspace buffer for a packed nvlist.

tools/tools/nvmf/nvmfdd/nvmfdd.c

@@ -474,7 +474,8 @@ main(int ac, char **av)
 	memset(&qparams, 0, sizeof(qparams));
 	tcp_qpair_params(&qparams, false, address, port);
 
-	io = nvmf_connect(na, &qparams, 1, info.mqes + 1, hostid,
+	io = nvmf_connect(na, &qparams, 1,
+	    MIN(NVMF_DEFAULT_IO_ENTRIES, info.mqes + 1), hostid,
 	    nvmf_cntlid(admin), av[2], hostnqn, 0);
 	if (io == NULL) {
 		warn("Failed to create I/O queue: %s",