diff --git a/drivers/vfio/pci/vfio_pci_intrs.c b/drivers/vfio/pci/vfio_pci_intrs.c
index 9dd49c9839ac..087e61c7cb37 100644
--- a/drivers/vfio/pci/vfio_pci_intrs.c
+++ b/drivers/vfio/pci/vfio_pci_intrs.c
@@ -752,41 +752,58 @@ static int vfio_pci_set_err_trigger(struct vfio_pci_device *vdev,
 				    unsigned index, unsigned start,
 				    unsigned count, uint32_t flags, void *data)
 {
-	int32_t fd = *(int32_t *)data;
-
-	if ((index != VFIO_PCI_ERR_IRQ_INDEX) ||
-	    !(flags & VFIO_IRQ_SET_DATA_TYPE_MASK))
+	if (index != VFIO_PCI_ERR_IRQ_INDEX || start != 0 || count > 1)
 		return -EINVAL;
 
 	/* DATA_NONE/DATA_BOOL enables loopback testing */
 	if (flags & VFIO_IRQ_SET_DATA_NONE) {
-		if (vdev->err_trigger)
-			eventfd_signal(vdev->err_trigger, 1);
-		return 0;
+		if (vdev->err_trigger) {
+			if (count) {
+				eventfd_signal(vdev->err_trigger, 1);
+			} else {
+				eventfd_ctx_put(vdev->err_trigger);
+				vdev->err_trigger = NULL;
+			}
+			return 0;
+		}
 	} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
-		uint8_t trigger = *(uint8_t *)data;
+		uint8_t trigger;
+
+		if (!count)
+			return -EINVAL;
+
+		trigger = *(uint8_t *)data;
 		if (trigger && vdev->err_trigger)
 			eventfd_signal(vdev->err_trigger, 1);
+
+		return 0;
+	} else if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
+		int32_t fd;
+
+		if (!count)
+			return -EINVAL;
+
+		fd = *(int32_t *)data;
+		if (fd == -1) {
+			if (vdev->err_trigger)
+				eventfd_ctx_put(vdev->err_trigger);
+			vdev->err_trigger = NULL;
+		} else if (fd >= 0) {
+			struct eventfd_ctx *efdctx;
+
+			efdctx = eventfd_ctx_fdget(fd);
+			if (IS_ERR(efdctx))
+				return PTR_ERR(efdctx);
+
+			if (vdev->err_trigger)
+				eventfd_ctx_put(vdev->err_trigger);
+
+			vdev->err_trigger = efdctx;
+		}
 		return 0;
 	}
 
-	/* Handle SET_DATA_EVENTFD */
-	if (fd == -1) {
-		if (vdev->err_trigger)
-			eventfd_ctx_put(vdev->err_trigger);
-		vdev->err_trigger = NULL;
-		return 0;
-	} else if (fd >= 0) {
-		struct eventfd_ctx *efdctx;
-		efdctx = eventfd_ctx_fdget(fd);
-		if (IS_ERR(efdctx))
-			return PTR_ERR(efdctx);
-		if (vdev->err_trigger)
-			eventfd_ctx_put(vdev->err_trigger);
-		vdev->err_trigger = efdctx;
-		return 0;
-	} else
-		return -EINVAL;
+	return -EINVAL;
 }
 int vfio_pci_set_irqs_ioctl(struct vfio_pci_device *vdev, uint32_t flags,
 			    unsigned index, unsigned start, unsigned count,