diff --git a/usr.sbin/bhyve/pci_virtio_scsi.c b/usr.sbin/bhyve/pci_virtio_scsi.c
--- a/usr.sbin/bhyve/pci_virtio_scsi.c
+++ b/usr.sbin/bhyve/pci_virtio_scsi.c
@@ -247,6 +247,15 @@
 	uint8_t		sense[];
 } __attribute__((packed));
 
+enum pci_vtscsi_walk {
+	PCI_VTSCSI_WALK_CONTINUE = 0,
+	PCI_VTSCSI_WALK_STOP,
+};
+
+typedef enum pci_vtscsi_walk pci_vtscsi_walk_t;
+typedef pci_vtscsi_walk_t pci_vtscsi_walk_request_queue_cb_t(
+    struct pci_vtscsi_queue *, struct pci_vtscsi_request *, void *);
+
 static void *pci_vtscsi_proc(void *);
 static void pci_vtscsi_reset(void *);
 static void pci_vtscsi_neg_features(void *, uint64_t);
@@ -259,6 +268,18 @@
 static inline int pci_vtscsi_get_lun(struct pci_vtscsi_softc *,
     const uint8_t *);
 
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_abort_task;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_abort_task_set;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_clear_aca;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_clear_task_set;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_i_t_nexus_reset;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_lun_reset;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_query_task;
+static pci_vtscsi_walk_request_queue_cb_t pci_vtscsi_tmf_handle_query_task_set;
+
+static pci_vtscsi_walk_t pci_vtscsi_walk_request_queue(
+    struct pci_vtscsi_queue *, pci_vtscsi_walk_request_queue_cb_t *, void *);
+
 static void pci_vtscsi_tmf_handle(struct pci_vtscsi_softc *, void *);
 static void pci_vtscsi_an_handle(struct pci_vtscsi_softc *, void *);
 static void pci_vtscsi_control_handle(struct pci_vtscsi_softc *, void *,
@@ -316,8 +337,10 @@
 		while (STAILQ_EMPTY(&q->vsq_requests) && !worker->vsw_exiting)
 			pthread_cond_wait(&q->vsq_cv, &q->vsq_rmtx);
 
-		if (worker->vsw_exiting)
-			break;
+		if (worker->vsw_exiting) {
+			pthread_mutex_unlock(&q->vsq_rmtx);
+			return (NULL);
+		}
 
 		req = pci_vtscsi_get_request(&q->vsq_requests);
 		pthread_mutex_unlock(&q->vsq_rmtx);
@@ -334,9 +357,6 @@
 
 		pci_vtscsi_return_request(q, req, iolen);
 	}
-
-	pthread_mutex_unlock(&q->vsq_rmtx);
-	return (NULL);
 }
 
 static void
@@ -445,6 +465,252 @@
 	return (((lun[2] << 8) | lun[3]) & 0x3fff);
 }
 
+/*
+ * ABORT TASK: Abort the specifed task queued for this LUN.
+ *
+ * We can stop once we have found the specified task queued for this LUN.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_abort_task(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_ABORT_TASK);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (pci_vtscsi_get_lun(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_lun(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (tmf->id != req->vsr_cmd_rd->id)
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	req->vsr_cmd_wr->response = VIRTIO_SCSI_S_ABORTED;
+	STAILQ_REMOVE(&q->vsq_requests, req, pci_vtscsi_request, vsr_link);
+	pci_vtscsi_return_request(q, req, 0);
+
+	return (PCI_VTSCSI_WALK_STOP);
+}
+
+/*
+ * ABORT TASK SET: Abort all tasks queued for this LUN.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_abort_task_set(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_ABORT_TASK_SET);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (pci_vtscsi_get_lun(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_lun(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	req->vsr_cmd_wr->response = VIRTIO_SCSI_S_ABORTED;
+	STAILQ_REMOVE(&q->vsq_requests, req, pci_vtscsi_request, vsr_link);
+	pci_vtscsi_return_request(q, req, 0);
+
+	return (PCI_VTSCSI_WALK_CONTINUE);
+}
+
+/*
+ * CLEAR ACA: Clear ACA (auto contingent allegiance) state.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_clear_aca(struct pci_vtscsi_queue *q __unused,
+    struct pci_vtscsi_request *req __unused, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_CLEAR_ACA);
+
+	/*
+	 * We don't implement handling of NACA=1 in the CONTROL byte at all.
+	 *
+	 * Thus, we probably should start filtering NORMACA in INQUIRY and
+	 * reject any command that sets NACA=1.
+	 *
+	 * In any case, there isn't anything we need to do with our queued
+	 * requests, so stop right here.
+	 */
+
+	return (PCI_VTSCSI_WALK_STOP);
+}
+
+/*
+ * CLEAR TASK SET: Clear all tasks queued for this LUN.
+ *
+ * All tasks in our queue were placed there by us, so there can be no other
+ * I_T nexus involved. Hence, this is handled the same as ABORT TASK SET.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_clear_task_set(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_CLEAR_TASK_SET);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (pci_vtscsi_get_lun(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_lun(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	req->vsr_cmd_wr->response = VIRTIO_SCSI_S_ABORTED;
+	STAILQ_REMOVE(&q->vsq_requests, req, pci_vtscsi_request, vsr_link);
+	pci_vtscsi_return_request(q, req, 0);
+
+	return (PCI_VTSCSI_WALK_CONTINUE);
+}
+
+/*
+ * I_T NEXUS RESET: Abort all tasks queued for any LUN of this target.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_i_t_nexus_reset(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_I_T_NEXUS_RESET);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	/*
+	 * T10 "06-026r4 SAM-4 TASK ABORTED status clarifications" indicates
+	 * that we should actually return ABORTED here, but other documents
+	 * such as the VirtIO spec suggest RESET.
+	 */
+	req->vsr_cmd_wr->response = VIRTIO_SCSI_S_RESET;
+	STAILQ_REMOVE(&q->vsq_requests, req, pci_vtscsi_request, vsr_link);
+	pci_vtscsi_return_request(q, req, 0);
+
+	return (PCI_VTSCSI_WALK_CONTINUE);
+}
+
+/*
+ * LOGICAL UNIT RESET: Abort all tasks queued for this LUN.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_lun_reset(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (pci_vtscsi_get_lun(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_lun(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	/*
+	 * T10 "06-026r4 SAM-4 TASK ABORTED status clarifications" indicates
+	 * that we should actually return ABORTED here, but other documents
+	 * such as the VirtIO spec suggest RESET.
+	 */
+	req->vsr_cmd_wr->response = VIRTIO_SCSI_S_RESET;
+	STAILQ_REMOVE(&q->vsq_requests, req, pci_vtscsi_request, vsr_link);
+	pci_vtscsi_return_request(q, req, 0);
+
+	return (PCI_VTSCSI_WALK_CONTINUE);
+}
+
+/*
+ * QUERY TASK: Is the specified task present in this LUN?
+ *
+ * We can stop once we have found the specified task queued for this LUN.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_query_task(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req,	void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (pci_vtscsi_get_lun(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_lun(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (tmf->id != req->vsr_cmd_rd->id)
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
+	return (PCI_VTSCSI_WALK_STOP);
+}
+
+/*
+ * QUERY TASK SET: Are there any tasks present in this LUN?
+ *
+ * We can stop as soon as we've found at least one task queued for this LUN.
+ */
+static pci_vtscsi_walk_t
+pci_vtscsi_tmf_handle_query_task_set(struct pci_vtscsi_queue *q,
+    struct pci_vtscsi_request *req, void *arg)
+{
+	struct pci_vtscsi_ctrl_tmf *tmf = arg;
+
+	assert(tmf->subtype == VIRTIO_SCSI_T_TMF_QUERY_TASK_SET);
+
+	if (pci_vtscsi_get_target(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_target(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	if (pci_vtscsi_get_lun(q->vsq_sc, tmf->lun) !=
+	    pci_vtscsi_get_lun(q->vsq_sc, req->vsr_cmd_rd->lun))
+		return (PCI_VTSCSI_WALK_CONTINUE);
+
+	tmf->response = VIRTIO_SCSI_S_FUNCTION_SUCCEEDED;
+	return (PCI_VTSCSI_WALK_STOP);
+}
+
+static pci_vtscsi_walk_t
+pci_vtscsi_walk_request_queue(struct pci_vtscsi_queue *q,
+    pci_vtscsi_walk_request_queue_cb_t cb, void *arg)
+{
+	struct pci_vtscsi_request *req, *tmp;
+
+	STAILQ_FOREACH_SAFE(req, &q->vsq_requests, vsr_link, tmp) {
+		if (cb(q, req, arg) == PCI_VTSCSI_WALK_STOP)
+			return (PCI_VTSCSI_WALK_STOP);
+	}
+
+	return (PCI_VTSCSI_WALK_CONTINUE);
+}
+
+static pci_vtscsi_walk_request_queue_cb_t *pci_vtscsi_tmf_handler_cb[] = {
+	pci_vtscsi_tmf_handle_abort_task,
+	pci_vtscsi_tmf_handle_abort_task_set,
+	pci_vtscsi_tmf_handle_clear_aca,
+	pci_vtscsi_tmf_handle_clear_task_set,
+	pci_vtscsi_tmf_handle_i_t_nexus_reset,
+	pci_vtscsi_tmf_handle_lun_reset,
+	pci_vtscsi_tmf_handle_query_task,
+	pci_vtscsi_tmf_handle_query_task_set
+};
+
 static void
 pci_vtscsi_tmf_handle(struct pci_vtscsi_softc *sc, void *buf)
 {
@@ -478,13 +744,41 @@
 	DPRINTF("TMF request tgt %d, lun %d, subtype %d, id %lu",
 	    target, pci_vtscsi_get_lun(sc, tmf->lun), tmf->subtype, tmf->id);
 
+	/*
+	 * Lock out all the worker threads from processing any waiting requests
+	 * while we're processing the TMF request. This also effectively blocks
+	 * pci_vtscsi_requestq_notify() from adding any new requests to the
+	 * request queue. This does not prevent any requests currently being
+	 * processed by the backend from being completed and returned, which
+	 * we must guarantee to adhere to the ordering requirements for any
+	 * TMF function which aborts tasks.
+	 */
+	for (int i = 0; i < VTSCSI_REQUESTQ; i++) {
+		struct pci_vtscsi_queue *q = &sc->vss_queues[i];
+
+		pthread_mutex_lock(&q->vsq_rmtx);
+	}
+
+	/*
+	 * CTL may set response to FAILURE for the TMF request.
+	 *
+	 * The default response of all TMF functions is FUNCTION COMPLETE if
+	 * there was no error, regardless of whether it actually succeeded or
+	 * not. The two notable exceptions are QUERY TASK and QUERY TASK SET,
+	 * which will explicitly return FUNCTION SUCCEEDED if the specified
+	 * task or any task was active in the target/LUN, respectively.
+	 *
+	 * Thus, we will call CTL first. Only if the response we get is
+	 * FUNCTION COMPLETE we'll continue processing the TMF function
+	 * on our queues.
+	 */
 	io = ctl_scsi_alloc_io(sc->vss_iid);
 	if (io == NULL) {
 		WPRINTF("failed to allocate ctl_io: err=%d (%s)",
 		    errno, strerror(errno));
 
 		tmf->response = VIRTIO_SCSI_S_FAILURE;
-		return;
+		goto out;
 	}
 
 	ctl_scsi_zero_io(io);
@@ -539,11 +833,54 @@
 	}
 
 	err = ioctl(fd, CTL_IO, io);
-	if (err != 0)
+	if (err != 0) {
 		WPRINTF("CTL_IO: err=%d (%s)", errno, strerror(errno));
+		tmf->response = VIRTIO_SCSI_S_FAILURE;
+	} else {
+		tmf->response = io->taskio.task_status;
+	}
 
-	tmf->response = io->taskio.task_status;
 	ctl_scsi_free_io(io);
+
+	if (tmf->response != VIRTIO_SCSI_S_FUNCTION_COMPLETE) {
+		/*
+		 * If this is either a FAILURE or FUNCTION REJECTED, we must
+		 * not continue to process the TMF function on our queued
+		 * requests.
+		 *
+		 * If it is FUNCTION SUCCEEDED, we do not need to process the
+		 * TMF function on our queued requests.
+		 *
+		 * If it is anything else, log a warning, but handle it the
+		 * same as above.
+		 */
+		if (tmf->response != VIRTIO_SCSI_S_FAILURE &&
+		    tmf->response != VIRTIO_SCSI_S_FUNCTION_REJECTED &&
+		    tmf->response != VIRTIO_SCSI_S_FUNCTION_SUCCEEDED) {
+			WPRINTF("pci_vtscsi_tmf_hdl: unexpected response from "
+			    "CTL: %d", tmf->response);
+		}
+	} else {
+		pci_vtscsi_walk_t ret = PCI_VTSCSI_WALK_CONTINUE;
+		int i;
+
+		for (i = 0;
+		    i < VTSCSI_REQUESTQ && ret != PCI_VTSCSI_WALK_STOP;
+		    i++) {
+			struct pci_vtscsi_queue *q = &sc->vss_queues[i];
+
+			ret = pci_vtscsi_walk_request_queue(q,
+			    pci_vtscsi_tmf_handler_cb[tmf->subtype], tmf);
+		}
+	}
+
+out:
+	/* Unlock the request queues before we return. */
+	for (int i = 0; i < VTSCSI_REQUESTQ; i++) {
+		struct pci_vtscsi_queue *q = &sc->vss_queues[i];
+
+		pthread_mutex_unlock(&q->vsq_rmtx);
+	}
 }
 
 static void