diff --git a/usr.sbin/bhyve/Makefile b/usr.sbin/bhyve/Makefile
--- a/usr.sbin/bhyve/Makefile
+++ b/usr.sbin/bhyve/Makefile
@@ -131,10 +131,6 @@
 CFLAGS+=-DGDB_LOG
 .endif
 
-# Disable thread safety analysis since it only finds very simple bugs and
-# yields many false positives.
-NO_WTHREAD_SAFETY=
-
 NO_WCAST_ALIGN=
 
 SUBDIR=	kbdlayout
diff --git a/usr.sbin/bhyve/gdb.c b/usr.sbin/bhyve/gdb.c
--- a/usr.sbin/bhyve/gdb.c
+++ b/usr.sbin/bhyve/gdb.c
@@ -729,7 +729,7 @@
  * debug server to pause or report an event.  vCPU threads wait here
  * as long as the debug server keeps them suspended.
  */
-static void
+static void __requires_exclusive(&gdb_lock)
 _gdb_cpu_suspend(int vcpu, bool report_stop)
 {
 
diff --git a/usr.sbin/bhyve/mem.c b/usr.sbin/bhyve/mem.c
--- a/usr.sbin/bhyve/mem.c
+++ b/usr.sbin/bhyve/mem.c
@@ -172,7 +172,7 @@
     void *arg)
 {
 	struct mmio_rb_range *entry;
-	int err, perror, immutable;
+	int err, perror;
 
 	pthread_rwlock_rdlock(&mmio_rwlock);
 	/*
@@ -209,15 +209,12 @@
 	 * deadlock on 'mmio_rwlock'. However by registering the extended
 	 * config space window as 'immutable' the deadlock can be avoided.
 	 */
-	immutable = (entry->mr_param.flags & MEM_F_IMMUTABLE);
-	if (immutable) {
+	if ((entry->mr_param.flags & MEM_F_IMMUTABLE) != 0) {
 		perror = pthread_rwlock_unlock(&mmio_rwlock);
 		assert(perror == 0);
-	}
-
-	err = cb(ctx, vcpu, paddr, &entry->mr_param, arg);
-
-	if (!immutable) {
+		err = cb(ctx, vcpu, paddr, &entry->mr_param, arg);
+	} else {
+		err = cb(ctx, vcpu, paddr, &entry->mr_param, arg);
 		perror = pthread_rwlock_unlock(&mmio_rwlock);
 		assert(perror == 0);
 	}
diff --git a/usr.sbin/bhyve/mevent.c b/usr.sbin/bhyve/mevent.c
--- a/usr.sbin/bhyve/mevent.c
+++ b/usr.sbin/bhyve/mevent.c
@@ -86,13 +86,13 @@
 
 static LIST_HEAD(listhead, mevent) global_head, change_head;
 
-static void
+static void __locks_exclusive(&mevent_lmutex)
 mevent_qlock(void)
 {
 	pthread_mutex_lock(&mevent_lmutex);
 }
 
-static void
+static void __unlocks(&mevent_lmutex)
 mevent_qunlock(void)
 {
 	pthread_mutex_unlock(&mevent_lmutex);
diff --git a/usr.sbin/bhyve/pci_e82545.c b/usr.sbin/bhyve/pci_e82545.c
--- a/usr.sbin/bhyve/pci_e82545.c
+++ b/usr.sbin/bhyve/pci_e82545.c
@@ -1461,7 +1461,7 @@
 	return (desc + 1);
 }
 
-static void
+static void __no_lock_analysis
 e82545_tx_run(struct e82545_softc *sc)
 {
 	uint32_t cause;
@@ -1539,7 +1539,7 @@
 	sc->esc_tx_enabled = 1;
 }
 
-static void
+static void __no_lock_analysis
 e82545_tx_disable(struct e82545_softc *sc)
 {
 
@@ -1555,7 +1555,7 @@
 	sc->esc_rx_enabled = 1;
 }
 
-static void
+static void __no_lock_analysis
 e82545_rx_disable(struct e82545_softc *sc)
 {
 
diff --git a/usr.sbin/bhyve/pci_virtio_net.c b/usr.sbin/bhyve/pci_virtio_net.c
--- a/usr.sbin/bhyve/pci_virtio_net.c
+++ b/usr.sbin/bhyve/pci_virtio_net.c
@@ -740,7 +740,7 @@
 }
 
 #ifdef BHYVE_SNAPSHOT
-static void
+static void __no_lock_analysis
 pci_vtnet_pause(void *vsc)
 {
 	struct pci_vtnet_softc *sc = vsc;
@@ -759,7 +759,7 @@
 	}
 }
 
-static void
+static void __no_lock_analysis
 pci_vtnet_resume(void *vsc)
 {
 	struct pci_vtnet_softc *sc = vsc;
diff --git a/usr.sbin/bhyve/pci_xhci.c b/usr.sbin/bhyve/pci_xhci.c
--- a/usr.sbin/bhyve/pci_xhci.c
+++ b/usr.sbin/bhyve/pci_xhci.c
@@ -1873,9 +1873,6 @@
 	if (err == XHCI_TRB_ERROR_EV_RING_FULL)
 		DPRINTF(("pci_xhci[%d]: event ring full", __LINE__));
 
-	if (!do_retry)
-		USB_DATA_XFER_UNLOCK(xfer);
-
 	if (do_intr)
 		pci_xhci_assert_interrupt(sc);
 
@@ -1885,9 +1882,9 @@
 		         __LINE__));
 		goto retry;
 	}
-
 	if (epid == 1)
 		USB_DATA_XFER_RESET(xfer);
+	USB_DATA_XFER_UNLOCK(xfer);
 
 	return (err);
 }
diff --git a/usr.sbin/bhyve/virtio.h b/usr.sbin/bhyve/virtio.h
--- a/usr.sbin/bhyve/virtio.h
+++ b/usr.sbin/bhyve/virtio.h
@@ -247,17 +247,19 @@
 	uint16_t vs_msix_cfg_idx;	/* MSI-X vector for config event */
 };
 
-#define	VS_LOCK(vs)							\
-do {									\
-	if (vs->vs_mtx)							\
-		pthread_mutex_lock(vs->vs_mtx);				\
-} while (0)
-
-#define	VS_UNLOCK(vs)							\
-do {									\
-	if (vs->vs_mtx)							\
-		pthread_mutex_unlock(vs->vs_mtx);			\
-} while (0)
+static inline void __no_lock_analysis
+VS_LOCK(struct virtio_softc *sc)
+{
+	if (sc->vs_mtx)
+		pthread_mutex_lock(sc->vs_mtx);
+}
+
+static inline void __no_lock_analysis
+VS_UNLOCK(struct virtio_softc *sc)
+{
+	if (sc->vs_mtx)
+		pthread_mutex_unlock(sc->vs_mtx);
+}
 
 struct virtio_consts {
 	const char *vc_name;		/* name of driver (for diagnostics) */
diff --git a/usr.sbin/bhyve/virtio.c b/usr.sbin/bhyve/virtio.c
--- a/usr.sbin/bhyve/virtio.c
+++ b/usr.sbin/bhyve/virtio.c
@@ -580,8 +580,7 @@
 	/* XXX probably should do something better than just assert() */
 	assert(baridx == 0);
 
-	if (vs->vs_mtx)
-		pthread_mutex_lock(vs->vs_mtx);
+	VS_LOCK(vs);
 
 	vc = vs->vs_vc;
 	name = vc->vc_name;
@@ -666,8 +665,7 @@
 		break;
 	}
 done:
-	if (vs->vs_mtx)
-		pthread_mutex_unlock(vs->vs_mtx);
+	VS_UNLOCK(vs);
 	return (value);
 }
 
@@ -702,8 +700,7 @@
 	/* XXX probably should do something better than just assert() */
 	assert(baridx == 0);
 
-	if (vs->vs_mtx)
-		pthread_mutex_lock(vs->vs_mtx);
+	VS_LOCK(vs);
 
 	vc = vs->vs_vc;
 	name = vc->vc_name;
@@ -809,8 +806,7 @@
 	    "%s: write config reg %s: curq %d >= max %d",
 	    name, cr->cr_name, vs->vs_curq, vc->vc_nvq);
 done:
-	if (vs->vs_mtx)
-		pthread_mutex_unlock(vs->vs_mtx);
+	VS_UNLOCK(vs);
 }
 
 #ifdef BHYVE_SNAPSHOT