Index: head/sys/dev/hyperv/include/hyperv.h
===================================================================
--- head/sys/dev/hyperv/include/hyperv.h
+++ head/sys/dev/hyperv/include/hyperv.h
@@ -551,8 +551,8 @@
 	hv_vmbus_pfn_channel_callback	on_channel_callback;
 	void*				channel_callback_context;
 
-	struct hypercall_sigevt_in	*ch_sigevt;
-	struct hyperv_dma		ch_sigevt_dma;
+	struct hyperv_mon_param		*ch_monprm;
+	struct hyperv_dma		ch_monprm_dma;
 
 	/*
 	 * From Win8, this field specifies the target virtual process
Index: head/sys/dev/hyperv/vmbus/hv_channel.c
===================================================================
--- head/sys/dev/hyperv/vmbus/hv_channel.c
+++ head/sys/dev/hyperv/vmbus/hv_channel.c
@@ -76,7 +76,7 @@
 			(uint32_t *)&monitor_page->
 				trigger_group[channel->monitor_group].u.pending);
 	} else {
-		hypercall_signal_event(channel->ch_sigevt_dma.hv_paddr);
+		hypercall_signal_event(channel->ch_monprm_dma.hv_paddr);
 	}
 
 }
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
@@ -296,20 +296,20 @@
 	if (offer->monitor_allocated)
 		new_channel->ch_flags |= VMBUS_CHAN_FLAG_HASMNF;
 
-	new_channel->ch_sigevt = hyperv_dmamem_alloc(
+	new_channel->ch_monprm = hyperv_dmamem_alloc(
 	    bus_get_dma_tag(sc->vmbus_dev),
-	    HYPERCALL_PARAM_ALIGN, 0, sizeof(struct hypercall_sigevt_in),
-	    &new_channel->ch_sigevt_dma, BUS_DMA_WAITOK | BUS_DMA_ZERO);
-	if (new_channel->ch_sigevt == NULL) {
-		device_printf(sc->vmbus_dev, "sigevt alloc failed\n");
+	    HYPERCALL_PARAM_ALIGN, 0, sizeof(struct hyperv_mon_param),
+	    &new_channel->ch_monprm_dma, BUS_DMA_WAITOK | BUS_DMA_ZERO);
+	if (new_channel->ch_monprm == NULL) {
+		device_printf(sc->vmbus_dev, "monprm alloc failed\n");
 		/* XXX */
 		mtx_destroy(&new_channel->sc_lock);
 		free(new_channel, M_DEVBUF);
 		return;
 	}
-	new_channel->ch_sigevt->hc_connid = VMBUS_CONNID_EVENT;
+	new_channel->ch_monprm->mp_connid = VMBUS_CONNID_EVENT;
 	if (sc->vmbus_version != VMBUS_VERSION_WS2008)
-		new_channel->ch_sigevt->hc_connid = offer->connection_id;
+		new_channel->ch_monprm->mp_connid = offer->connection_id;
 
 	new_channel->monitor_group = (uint8_t) offer->monitor_id / 32;
 	new_channel->monitor_bit = (uint8_t) offer->monitor_id % 32;
Index: head/sys/dev/hyperv/vmbus/hyperv.c
===================================================================
--- head/sys/dev/hyperv/vmbus/hyperv.c
+++ head/sys/dev/hyperv/vmbus/hyperv.c
@@ -109,10 +109,10 @@
 }
 
 uint64_t
-hypercall_signal_event(bus_addr_t sigevt_paddr)
+hypercall_signal_event(bus_addr_t monprm_paddr)
 {
 	return hypercall_md(hypercall_context.hc_addr,
-	    HYPERCALL_SIGNAL_EVENT, sigevt_paddr, 0);
+	    HYPERCALL_SIGNAL_EVENT, monprm_paddr, 0);
 }
 
 int
Index: head/sys/dev/hyperv/vmbus/hyperv_reg.h
===================================================================
--- head/sys/dev/hyperv/vmbus/hyperv_reg.h
+++ head/sys/dev/hyperv/vmbus/hyperv_reg.h
@@ -133,6 +133,15 @@
 #define CPUID_LEAF_HV_HWFEATURES	0x40000006
 
 /*
+ * Hyper-V Monitor Notification Facility
+ */
+struct hyperv_mon_param {
+	uint32_t	mp_connid;
+	uint16_t	mp_evtflag_ofs;
+	uint16_t	mp_rsvd;
+} __packed;
+
+/*
  * Hyper-V message types
  */
 #define HYPERV_MSGTYPE_NONE		0
@@ -181,11 +190,8 @@
 
 /*
  * HYPERCALL_SIGNAL_EVENT
+ *
+ * struct hyperv_mon_param.
  */
-struct hypercall_sigevt_in {
-	uint32_t	hc_connid;
-	uint16_t	hc_evtflag_ofs;
-	uint16_t	hc_rsvd;
-} __packed;
 
 #endif	/* !_HYPERV_REG_H_ */
Index: head/sys/dev/hyperv/vmbus/hyperv_var.h
===================================================================
--- head/sys/dev/hyperv/vmbus/hyperv_var.h
+++ head/sys/dev/hyperv/vmbus/hyperv_var.h
@@ -39,6 +39,6 @@
 extern u_int	hyperv_recommends;
 
 uint64_t	hypercall_post_message(bus_addr_t msg_paddr);
-uint64_t	hypercall_signal_event(bus_addr_t sigevt_paddr);
+uint64_t	hypercall_signal_event(bus_addr_t monprm_paddr);
 
 #endif	/* !_HYPERV_VAR_H_ */