2 files changed, 50 insertions, 6 deletions

diff --git a/include/linux/virtio_9p.h b/include/linux/virtio_9p.h
index 332275080083..5cf11765146b 100644
--- a/include/linux/virtio_9p.h
+++ b/include/linux/virtio_9p.h
@@ -5,4 +5,16 @@
 #include <linux/virtio_ids.h>
 #include <linux/virtio_config.h>
 
+/* The feature bitmap for virtio 9P */
+
+/* The mount point is specified in a config variable */
+#define VIRTIO_9P_MOUNT_TAG 0
+
+struct virtio_9p_config {
+        /* length of the tag name */
+        __u16 tag_len;
+        /* non-NULL terminated tag name */
+        __u8 tag[0];
+} __attribute__((packed));
+
 #endif /* _LINUX_VIRTIO_9P_H */
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 0aaed4819379..026775ad391a 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -78,6 +78,12 @@ struct virtio_chan {
         /* Scatterlist: can be too big for stack. */
         struct scatterlist sg[VIRTQUEUE_NUM];
 
+        int tag_len;
+        /*
+         * tag name to identify a mount Non-null terminated
+         */
+        char *tag;
+
         struct list_head chan_list;
 };
 
@@ -224,6 +230,8 @@ p9_virtio_request(struct p9_client *client, struct p9_req_t *req)
 
 static int p9_virtio_probe(struct virtio_device *vdev)
 {
+        __u16 tag_len;
+        char *tag;
         int err;
         struct virtio_chan *chan;
 
@@ -248,6 +256,23 @@ static int p9_virtio_probe(struct virtio_device *vdev)
         sg_init_table(chan->sg, VIRTQUEUE_NUM);
 
         chan->inuse = false;
+        if (virtio_has_feature(vdev, VIRTIO_9P_MOUNT_TAG)) {
+                vdev->config->get(vdev,
+                                offsetof(struct virtio_9p_config, tag_len),
+                                &tag_len, sizeof(tag_len));
+        } else {
+                err = -EINVAL;
+                goto out_free_vq;
+        }
+        tag = kmalloc(tag_len, GFP_KERNEL);
+        if (!tag) {
+                err = -ENOMEM;
+                goto out_free_vq;
+        }
+        vdev->config->get(vdev, offsetof(struct virtio_9p_config, tag),
+                        tag, tag_len);
+        chan->tag = tag;
+        chan->tag_len = tag_len;
         mutex_lock(&virtio_9p_lock);
         list_add_tail(&chan->chan_list, &virtio_chan_list);
         mutex_unlock(&virtio_9p_lock);
@@ -284,7 +309,7 @@ p9_virtio_create(struct p9_client *client, const char *devname, char *args)
 
         mutex_lock(&virtio_9p_lock);
         list_for_each_entry(chan, &virtio_chan_list, chan_list) {
-                if (!strcmp(devname, dev_name(&chan->vdev->dev))) {
+                if (!strncmp(devname, chan->tag, chan->tag_len)) {
                         if (!chan->inuse) {
                                 chan->inuse = true;
                                 found = 1;
@@ -323,6 +348,7 @@ static void p9_virtio_remove(struct virtio_device *vdev)
         mutex_lock(&virtio_9p_lock);
         list_del(&chan->chan_list);
         mutex_unlock(&virtio_9p_lock);
+        kfree(chan->tag);
         kfree(chan);
 
 }
@@ -332,13 +358,19 @@ static struct virtio_device_id id_table[] = {
         { 0 },
 };
 
+static unsigned int features[] = {
+        VIRTIO_9P_MOUNT_TAG,
+};
+
 /* The standard "struct lguest_driver": */
 static struct virtio_driver p9_virtio_drv = {
-        .driver.name =  KBUILD_MODNAME,
-        .driver.owner = THIS_MODULE,
-        .id_table =     id_table,
-        .probe =        p9_virtio_probe,
-        .remove =       p9_virtio_remove,
+        .feature_table  = features,
+        .feature_table_size = ARRAY_SIZE(features),
+        .driver.name    = KBUILD_MODNAME,
+        .driver.owner   = THIS_MODULE,
+        .id_table       = id_table,
+        .probe          = p9_virtio_probe,
+        .remove         = p9_virtio_remove,
 };
 
 static struct p9_trans_module p9_virtio_trans = {