diff --git a/app/nvmf_tgt/nvmf_tgt.c b/app/nvmf_tgt/nvmf_tgt.c
index 86ed17c4d..238f9a47e 100644
--- a/app/nvmf_tgt/nvmf_tgt.c
+++ b/app/nvmf_tgt/nvmf_tgt.c
@@ -47,7 +47,6 @@
 #include "spdk/event.h"
 #include "spdk/log.h"
 #include "spdk/nvme.h"
-#include "spdk/io_channel.h"
 
 #define SPDK_NVMF_BUILD_ETC "/usr/local/etc/nvmf"
 #define SPDK_NVMF_DEFAULT_CONFIG SPDK_NVMF_BUILD_ETC "/nvmf.conf"
@@ -177,20 +176,9 @@ _nvmf_tgt_start_subsystem(void *arg1, void *arg2)
 {
 	struct nvmf_tgt_subsystem *app_subsys = arg1;
 	struct spdk_nvmf_subsystem *subsystem = app_subsys->subsystem;
-	struct spdk_bdev *bdev;
-	struct spdk_io_channel *ch;
 	int lcore = spdk_app_get_current_core();
-	int i;
 
-	if (subsystem->subtype == SPDK_NVMF_SUBTYPE_NVME &&
-	    subsystem->mode == NVMF_SUBSYSTEM_MODE_VIRTUAL) {
-		for (i = 0; i < subsystem->dev.virt.ns_count; i++) {
-			bdev = subsystem->dev.virt.ns_list[i];
-			ch = spdk_bdev_get_io_channel(bdev, SPDK_IO_PRIORITY_DEFAULT);
-			assert(ch != NULL);
-			subsystem->dev.virt.ch[i] = ch;
-		}
-	}
+	spdk_nvmf_subsystem_start(subsystem);
 
 	spdk_poller_register(&app_subsys->poller, subsystem_poll, app_subsys, lcore, 0);
 }
diff --git a/include/spdk/nvmf.h b/include/spdk/nvmf.h
index ad6d49b32..6694a2a06 100644
--- a/include/spdk/nvmf.h
+++ b/include/spdk/nvmf.h
@@ -84,6 +84,11 @@ struct spdk_nvmf_host {
 };
 
 struct spdk_nvmf_ctrlr_ops {
+	/**
+	 * Initialize the controller.
+	 */
+	int (*attach)(struct spdk_nvmf_subsystem *subsystem);
+
 	/**
 	 * Set NVMe ctrlr AER.
 	 */
@@ -165,6 +170,13 @@ struct spdk_nvmf_subsystem *spdk_nvmf_create_subsystem(const char *nqn,
 		spdk_nvmf_subsystem_connect_fn connect_cb,
 		spdk_nvmf_subsystem_disconnect_fn disconnect_cb);
 
+/**
+ * Initialize the subsystem on the thread that will be used to poll it.
+ *
+ * \param subsystem Subsystem that will be polled on this core.
+ */
+int spdk_nvmf_subsystem_start(struct spdk_nvmf_subsystem *subsystem);
+
 void spdk_nvmf_delete_subsystem(struct spdk_nvmf_subsystem *subsystem);
 
 struct spdk_nvmf_subsystem *
diff --git a/lib/nvmf/direct.c b/lib/nvmf/direct.c
index e8f1be128..7210fc22b 100644
--- a/lib/nvmf/direct.c
+++ b/lib/nvmf/direct.c
@@ -261,6 +261,12 @@ nvmf_direct_ctrlr_complete_aer(void *arg, const struct spdk_nvme_cpl *cpl)
 	}
 }
 
+static int
+nvmf_direct_ctrlr_attach(struct spdk_nvmf_subsystem *subsystem)
+{
+	return 0;
+}
+
 static void
 nvmf_direct_ctrlr_set_aer_callback(struct spdk_nvmf_subsystem *subsys)
 {
@@ -269,6 +275,7 @@ nvmf_direct_ctrlr_set_aer_callback(struct spdk_nvmf_subsystem *subsys)
 }
 
 const struct spdk_nvmf_ctrlr_ops spdk_nvmf_direct_ctrlr_ops = {
+	.attach				= nvmf_direct_ctrlr_attach,
 	.set_aer_callback		= nvmf_direct_ctrlr_set_aer_callback,
 	.ctrlr_get_data			= nvmf_direct_ctrlr_get_data,
 	.process_admin_cmd		= nvmf_direct_ctrlr_process_admin_cmd,
diff --git a/lib/nvmf/subsystem.c b/lib/nvmf/subsystem.c
index 6477e5aef..cb26cefbe 100644
--- a/lib/nvmf/subsystem.c
+++ b/lib/nvmf/subsystem.c
@@ -122,6 +122,16 @@ spdk_nvmf_subsystem_host_allowed(struct spdk_nvmf_subsystem *subsystem, const ch
 	return false;
 }
 
+int
+spdk_nvmf_subsystem_start(struct spdk_nvmf_subsystem *subsystem)
+{
+	if (subsystem->subtype == SPDK_NVMF_SUBTYPE_NVME) {
+		return subsystem->ops->attach(subsystem);
+	}
+
+	return 0;
+}
+
 void
 spdk_nvmf_subsystem_poll(struct spdk_nvmf_subsystem *subsystem)
 {
diff --git a/lib/nvmf/virtual.c b/lib/nvmf/virtual.c
index 9ed9e1a58..2674f9e0e 100644
--- a/lib/nvmf/virtual.c
+++ b/lib/nvmf/virtual.c
@@ -520,6 +520,26 @@ nvmf_virtual_ctrlr_process_io_cmd(struct spdk_nvmf_request *req)
 	}
 }
 
+static int
+nvmf_virtual_ctrlr_attach(struct spdk_nvmf_subsystem *subsystem)
+{
+	struct spdk_bdev *bdev;
+	struct spdk_io_channel *ch;
+	uint32_t i;
+
+	for (i = 0; i < subsystem->dev.virt.ns_count; i++) {
+		bdev = subsystem->dev.virt.ns_list[i];
+		ch = spdk_bdev_get_io_channel(bdev, SPDK_IO_PRIORITY_DEFAULT);
+		if (ch == NULL) {
+			SPDK_ERRLOG("io_channel allocation failed\n");
+			return -1;
+		}
+		subsystem->dev.virt.ch[i] = ch;
+	}
+
+	return 0;
+}
+
 static void
 nvmf_virtual_ctrlr_detach(struct spdk_nvmf_subsystem *subsystem)
 {
@@ -542,6 +562,7 @@ nvmf_virtual_ctrlr_set_aer_callback(struct spdk_nvmf_subsystem *subsys)
 }
 
 const struct spdk_nvmf_ctrlr_ops spdk_nvmf_virtual_ctrlr_ops = {
+	.attach				= nvmf_virtual_ctrlr_attach,
 	.set_aer_callback		= nvmf_virtual_ctrlr_set_aer_callback,
 	.ctrlr_get_data			= nvmf_virtual_ctrlr_get_data,
 	.process_admin_cmd		= nvmf_virtual_ctrlr_process_admin_cmd,
diff --git a/test/lib/nvmf/virtual/virtual_ut.c b/test/lib/nvmf/virtual/virtual_ut.c
index c4ee0258a..5ac534b54 100644
--- a/test/lib/nvmf/virtual/virtual_ut.c
+++ b/test/lib/nvmf/virtual/virtual_ut.c
@@ -100,6 +100,12 @@ spdk_nvmf_request_complete(struct spdk_nvmf_request *req)
 	return -1;
 }
 
+struct spdk_io_channel *
+spdk_bdev_get_io_channel(struct spdk_bdev *bdev, uint32_t priority)
+{
+	return NULL;
+}
+
 struct spdk_bdev_io *spdk_bdev_flush(struct spdk_bdev *bdev, struct spdk_io_channel *ch,
 				     uint64_t offset, uint64_t length, spdk_bdev_io_completion_cb cb, void *cb_arg)
 {