Index: head/sys/dev/hyperv/include/hyperv.h
===================================================================
--- head/sys/dev/hyperv/include/hyperv.h
+++ head/sys/dev/hyperv/include/hyperv.h
@@ -336,7 +336,7 @@
 	struct sysctl_ctx_list		ch_sysctl_ctx;
 } hv_vmbus_channel;
 
-#define HV_VMBUS_CHAN_ISPRIMARY(chan)	((chan)->primary_channel == NULL)
+#define VMBUS_CHAN_ISPRIMARY(chan)	((chan)->ch_subidx == 0)
 
 #define VMBUS_CHAN_FLAG_HASMNF		0x0001
 /*
Index: head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
===================================================================
--- head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
+++ head/sys/dev/hyperv/netvsc/hv_netvsc_drv_freebsd.c
@@ -2957,7 +2957,7 @@
 hn_subchan_attach(struct hn_softc *sc, struct hv_vmbus_channel *chan)
 {
 
-	KASSERT(!HV_VMBUS_CHAN_ISPRIMARY(chan),
+	KASSERT(!VMBUS_CHAN_ISPRIMARY(chan),
 	    ("subchannel callback on primary channel"));
 	KASSERT(chan->ch_subidx > 0,
 	    ("invalid channel subidx %u",
Index: head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
===================================================================
--- head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
+++ head/sys/dev/hyperv/vmbus/hv_channel_mgmt.c
@@ -285,7 +285,7 @@
 		return;
 	}
 
-	if (HV_VMBUS_CHAN_ISPRIMARY(chan)) {
+	if (VMBUS_CHAN_ISPRIMARY(chan)) {
 		/*
 		 * Add device for this primary channel.
 		 *
@@ -332,7 +332,7 @@
 {
 	struct hv_vmbus_channel *chan = xchan;
 
-	if (HV_VMBUS_CHAN_ISPRIMARY(chan)) {
+	if (VMBUS_CHAN_ISPRIMARY(chan)) {
 		/* Only primary channel owns the device */
 		hv_vmbus_child_device_unregister(chan);
 		/* NOTE: DO NOT free primary channel for now */
@@ -413,7 +413,7 @@
 	    channel = TAILQ_FIRST(&sc->vmbus_chlist);
 	    TAILQ_REMOVE(&sc->vmbus_chlist, channel, ch_link);
 
-	    if (HV_VMBUS_CHAN_ISPRIMARY(channel)) {
+	    if (VMBUS_CHAN_ISPRIMARY(channel)) {
 		/* Only primary channel owns the device */
 		hv_vmbus_child_device_unregister(channel);
 	    }