virtio/9p: verify device has config space

Some devices might not implement config space access (e.g. remoteproc used not to - before 3.9). virtio/9p needs config space access so make it fail gracefully if not there. Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Rusty Russell <[email protected]>
jljusten · Jan 21, 2015 · 7754f53 · 7754f53
1 parent 7f870c8
commit 7754f53
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
@@ -524,6 +524,12 @@ static int p9_virtio_probe(struct virtio_device *vdev)
 	int err;
 	struct virtio_chan *chan;
 
+	if (!vdev->config->get) {
+		dev_err(&vdev->dev, "%s failure: config access disabled\n",
+			__func__);
+		return -EINVAL;
+	}
+
 	chan = kmalloc(sizeof(struct virtio_chan), GFP_KERNEL);
 	if (!chan) {
 		pr_err("Failed to allocate virtio 9P channel\n");