commit 8bfd8b54dd79350b2ec286e076c260c97227c505
Author: Ryota Ozaki <ozaki-r@iij.ad.jp>
Date:   Mon Mar 17 16:59:20 2025 +0900

    vio9p: export tag via sysctl

diff --git a/sys/dev/pci/vio9p.c b/sys/dev/pci/vio9p.c
index 17189a4988e..6fac6e66cf2 100644
--- a/sys/dev/pci/vio9p.c
+++ b/sys/dev/pci/vio9p.c
@@ -490,6 +490,7 @@ vio9p_attach(device_t parent, device_t self, void *aux)
 	struct virtio_softc *vsc = device_private(parent);
 	uint64_t features;
 	int error;
+	const struct sysctlnode *node;
 
 	if (virtio_child(vsc) != NULL) {
 		aprint_normal(": child already attached for %s; "
@@ -553,6 +554,15 @@ 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,
+	    device_xname(self), 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, sc->sc_vq,
 	    __arraycount(sc->sc_vq), NULL,
 	    VIRTIO_F_INTR_MPSAFE | VIRTIO_F_INTR_SOFTINT);