commit c82d42f5c85805344c6976708087682bc266cbf7
Author: Ryota Ozaki <ozaki-r@iij.ad.jp>
Date:   Wed Nov 20 10:37:38 2024 +0900

    vio9p: export tag via sysctl

diff --git a/sys/dev/pci/vio9p.c b/sys/dev/pci/vio9p.c
index 27c09b540a71..1a693c271590 100644
--- a/sys/dev/pci/vio9p.c
+++ b/sys/dev/pci/vio9p.c
@@ -482,6 +482,7 @@ vio9p_attach(device_t parent, device_t self, void *aux)
 	struct vio9p_softc *sc = device_private(self);
 	struct virtio_softc *vsc = device_private(parent);
 	int error;
+	const struct sysctlnode *node;
 
 	if (virtio_child(vsc) != NULL) {
 		aprint_normal(": child already attached for %s; "
@@ -546,6 +547,15 @@ vio9p_attach(device_t parent, device_t self, void *aux)
 	vio9p_read_config(sc);
 	aprint_normal_dev(self, "tagged as %s\n", sc->sc_tag);
 
+	sysctl_createv(NULL, 0, NULL, &node, 0, CTLTYPE_NODE,
+	    "vio9p", SYSCTL_DESCR("VirtIO 9p status"),
+	    NULL, 0, NULL, 0,
+	    CTL_HW, CTL_CREATE, CTL_EOL);
+	sysctl_createv(NULL, 0, NULL, NULL, 0, CTLTYPE_STRING,
+	    "tag", SYSCTL_DESCR("VirtIO 9p tag value"),
+	    NULL, 0, sc->sc_tag, 0,
+	    CTL_HW, node->sysctl_num, CTL_CREATE, CTL_EOL);
+
 	error = virtio_child_attach_finish(vsc);
 	if (error != 0)
 		goto err_mutex;