Index: sys/dev/hyperv/vmbus/hv_channel.c
===================================================================
--- sys/dev/hyperv/vmbus/hv_channel.c
+++ sys/dev/hyperv/vmbus/hv_channel.c
@@ -427,61 +427,44 @@
 	return 0;
 }
 
-/**
- * @brief Teardown the specified GPADL handle
+/*
+ * Disconnect the GPA from the target channel
  */
 int
-hv_vmbus_channel_teardown_gpdal(
-	hv_vmbus_channel*	channel,
-	uint32_t		gpadl_handle)
+hv_vmbus_channel_teardown_gpdal(struct hv_vmbus_channel *chan, uint32_t gpadl)
 {
-	int					ret = 0;
-	hv_vmbus_channel_gpadl_teardown*	msg;
-	hv_vmbus_channel_msg_info*		info;
-
-	info = (hv_vmbus_channel_msg_info *)
-		malloc(	sizeof(hv_vmbus_channel_msg_info) +
-			sizeof(hv_vmbus_channel_gpadl_teardown),
-				M_DEVBUF, M_NOWAIT);
-	KASSERT(info != NULL,
-	    ("Error VMBUS: malloc failed to allocate Gpadl Teardown Msg!"));
-	if (info == NULL) {
-	    ret = ENOMEM;
-	    goto cleanup;
-	}
-
-	sema_init(&info->wait_sema, 0, "Open Info Sema");
-
-	msg = (hv_vmbus_channel_gpadl_teardown*) info->msg;
+	struct vmbus_softc *sc = chan->vmbus_sc;
+	struct vmbus_msghc *mh;
+	struct vmbus_chanmsg_gpadl_disconn *req;
+	int error;
 
-	msg->header.message_type = HV_CHANNEL_MESSAGE_GPADL_TEARDOWN;
-	msg->child_rel_id = channel->offer_msg.child_rel_id;
-	msg->gpadl = gpadl_handle;
+	mh = vmbus_msghc_get(sc, sizeof(*req));
+	if (mh == NULL) {
+		device_printf(sc->vmbus_dev,
+		    "can not get msg hypercall for gpa x->chan%u\n",
+		    chan->offer_msg.child_rel_id);
+		return EBUSY;
+	}
 
-	mtx_lock(&hv_vmbus_g_connection.channel_msg_lock);
-	TAILQ_INSERT_TAIL(&hv_vmbus_g_connection.channel_msg_anchor,
-			info, msg_list_entry);
-	mtx_unlock(&hv_vmbus_g_connection.channel_msg_lock);
+	req = vmbus_msghc_dataptr(mh);
+	req->chm_hdr.chm_type = VMBUS_CHANMSG_TYPE_GPADL_DISCONN;
+	req->chm_chanid = chan->offer_msg.child_rel_id;
+	req->chm_gpadl = gpadl;
 
-	ret = hv_vmbus_post_message(msg,
-			sizeof(hv_vmbus_channel_gpadl_teardown));
-	if (ret != 0) 
-	    goto cleanup;
-	
-	ret = sema_timedwait(&info->wait_sema, 5 * hz); /* KYS 5 seconds */
+	error = vmbus_msghc_exec(sc, mh);
+	if (error) {
+		device_printf(sc->vmbus_dev,
+		    "gpa x->chan%u msg hypercall exec failed: %d\n",
+		    chan->offer_msg.child_rel_id, error);
+		vmbus_msghc_put(sc, mh);
+		return error;
+	}
 
-cleanup:
-	/*
-	 * Received a torndown response
-	 */
-	mtx_lock(&hv_vmbus_g_connection.channel_msg_lock);
-	TAILQ_REMOVE(&hv_vmbus_g_connection.channel_msg_anchor,
-			info, msg_list_entry);
-	mtx_unlock(&hv_vmbus_g_connection.channel_msg_lock);
-	sema_destroy(&info->wait_sema);
-	free(info, M_DEVBUF);
+	vmbus_msghc_wait_result(sc, mh);
+	/* Discard result; no useful information */
+	vmbus_msghc_put(sc, mh);
 
-	return (ret);
+	return 0;
 }
 
 static void
Index: sys/dev/hyperv/vmbus/hv_channel_mgmt.c
===================================================================
--- sys/dev/hyperv/vmbus/hv_channel_mgmt.c
+++ sys/dev/hyperv/vmbus/hv_channel_mgmt.c
@@ -452,42 +452,7 @@
 vmbus_channel_on_gpadl_torndown(struct vmbus_softc *sc,
     const struct vmbus_message *msg)
 {
-	const hv_vmbus_channel_msg_header *hdr =
-	    (const hv_vmbus_channel_msg_header *)msg->msg_data;
-
-	const hv_vmbus_channel_gpadl_torndown *gpadl_torndown;
-	hv_vmbus_channel_msg_info*		msg_info;
-	hv_vmbus_channel_msg_header*		requestHeader;
-	hv_vmbus_channel_gpadl_teardown*	gpadlTeardown;
-
-	gpadl_torndown = (const hv_vmbus_channel_gpadl_torndown *)hdr;
-
-	/*
-	 * Find the open msg, copy the result and signal/unblock the
-	 * wait event.
-	 */
-
-	mtx_lock(&hv_vmbus_g_connection.channel_msg_lock);
-
-	TAILQ_FOREACH(msg_info, &hv_vmbus_g_connection.channel_msg_anchor,
-		msg_list_entry) {
-	    requestHeader = (hv_vmbus_channel_msg_header*) msg_info->msg;
-
-	    if (requestHeader->message_type
-		    == HV_CHANNEL_MESSAGE_GPADL_TEARDOWN) {
-		gpadlTeardown =
-		    (hv_vmbus_channel_gpadl_teardown*) requestHeader;
-
-		if (gpadl_torndown->gpadl == gpadlTeardown->gpadl) {
-		    memcpy(&msg_info->response.gpadl_torndown,
-			gpadl_torndown,
-			sizeof(hv_vmbus_channel_gpadl_torndown));
-		    sema_post(&msg_info->wait_sema);
-		    break;
-		}
-	    }
-	}
-    mtx_unlock(&hv_vmbus_g_connection.channel_msg_lock);
+	vmbus_msghc_wakeup(sc, msg);
 }
 
 static void
Index: sys/dev/hyperv/vmbus/vmbus_reg.h
===================================================================
--- sys/dev/hyperv/vmbus/vmbus_reg.h
+++ sys/dev/hyperv/vmbus/vmbus_reg.h
@@ -99,7 +99,9 @@
 #define VMBUS_CHANMSG_TYPE_CHCLOSE		7	/* REQ */
 #define VMBUS_CHANMSG_TYPE_GPADL_CONN		8	/* REQ */
 #define VMBUS_CHANMSG_TYPE_GPADL_SUBCONN	9	/* REQ */
-#define VMBUS_CHANMSG_TYPE_GPADP_CONNRESP	10	/* RESP */
+#define VMBUS_CHANMSG_TYPE_GPADL_CONNRESP	10	/* RESP */
+#define VMBUS_CHANMSG_TYPE_GPADL_DISCONN	11	/* REQ */
+#define VMBUS_CHANMSG_TYPE_GPADL_DISCONNRESP	12	/* RESP */
 #define VMBUS_CHANMSG_TYPE_INIT_CONTACT		14	/* REQ */
 #define VMBUS_CHANMSG_TYPE_VERSION_RESP		15	/* RESP */
 #define VMBUS_CHANMSG_TYPE_UNLOAD		16	/* REQ */
@@ -197,4 +199,11 @@
 	uint32_t	chm_chanid;
 } __packed;
 
+/* VMBUS_CHANMSG_TYPE_GPADL_DISCONN */
+struct vmbus_chanmsg_gpadl_disconn {
+	struct vmbus_chanmsg_hdr chm_hdr;
+	uint32_t	chm_chanid;
+	uint32_t	chm_gpadl;
+} __packed;
+
 #endif	/* !_VMBUS_REG_H_ */