Remove port data; deregister from the hvc core if it's a console port.
Signed-off-by: Amit Shah <amit.shah@xxxxxxxxxx>
---
drivers/char/virtio_console.c | 64 ++++++++++++++++++++++++++++++++++++++++
include/linux/virtio_console.h | 2 +
2 files changed, 66 insertions(+), 0 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 90bb221..9035f80 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -719,6 +719,42 @@ int init_port_console(struct virtio_console_port *port)
return ret;
}
+static struct attribute_group virtcon_attribute_group;
+
+/* Remove port-specific data. */
+static int virtcons_remove_port_data(struct virtio_console_port *port)
+{
+ struct virtio_console_port_buffer *buf, *buf2;
+ struct virtio_console_control cpkt;
+
+ if (port->guest_connected) {
+ cpkt.event = VIRTIO_CONSOLE_PORT_OPEN;
+ cpkt.value = 0;
+ send_buf(port, (char *)&cpkt, sizeof(cpkt),
+ VIRTIO_CONSOLE_ID_CONTROL, false);
+ }
+ if (is_console_port(port))
+ hvc_remove(port->hvc);
+
+ sysfs_remove_group(&port->dev->kobj, &virtcon_attribute_group);
+ device_destroy(virtconsole.class, port->dev->devt);
+ unregister_chrdev_region(port->dev->devt, 1);
+ cdev_del(&port->cdev);
+
+ kfree(port->name);
+
+ /* Remove the buffers in which we have unconsumed data */
+ spin_lock(&port->readbuf_list_lock);
+ list_for_each_entry_safe(buf, buf2, &port->readbuf_head, list) {
+ list_del(&buf->list);
+ kfree(buf->buf);
+ kfree(buf);
+ }
+ spin_unlock(&port->readbuf_list_lock);
+ debugfs_remove(port->debugfs_file);
+ return 0;
+}
+
/* Any private messages that the Host and Guest want to share */
static void handle_control_message(struct virtio_console_port *port,
struct virtio_console_port_buffer *buf)
@@ -799,6 +835,30 @@ static void handle_control_message(struct virtio_console_port *port,
case VIRTIO_CONSOLE_CACHE_BUFFERS:
port->cache_buffers = cpkt->value;
break;
+ case VIRTIO_CONSOLE_PORT_REMOVE:
+ /*
+ * Hot unplug the port. We don't decrement nr_ports
+ * since we don't want to deal with extra complexities
+ * of using the lowest-available port id: We can just
+ * pick up the nr_ports number as the id and not have
+ * userspace send it to us. This helps us in two ways:
+ *
+ * - We don't need to have a 'port_id' field in the
+ * config space when a port is hot-added. This is a
+ * good thing as we might queue up multiple hotplug
+ * requests issued in our workqueue.
+ *
+ * - Another way to deal with this would have been to
+ * use a bitmap of the active ports and select the
+ * lowest non-active port from that map. That bloats
+ * the already tight config space and we would end
+ * up artificially limiting the max. number of ports
+ * to sizeof(bitmap). Right now we can support 2^32
+ * ports (as the port id is stored in a u32 type).
+ *
+ */
+ virtcons_remove_port_data(port);
+ break;
}
}
@@ -1280,6 +1340,9 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_CACHING))
vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_CACHING;
+ if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_UNPLUG))
+ vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_UNPLUG;
+
vdev->config->finalize_features(vdev);
/* Find the queues. */
/* FIXME: This is why we want to wean off hvc: we do nothing
@@ -1333,6 +1396,7 @@ static unsigned int features[] = {
VIRTIO_CONSOLE_F_MULTIPORT,
VIRTIO_CONSOLE_F_THROTTLE,
VIRTIO_CONSOLE_F_CACHING,
+ VIRTIO_CONSOLE_F_UNPLUG,
};
static struct virtio_driver virtio_console = {
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index ce5eef2..703696a 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -15,6 +15,7 @@
#define VIRTIO_CONSOLE_F_MULTIPORT 1 /* Does host provide multiple ports? */
#define VIRTIO_CONSOLE_F_THROTTLE 2 /* Do we throttle data to prevent OOM */
#define VIRTIO_CONSOLE_F_CACHING 3 /* Do we cache data after port close? */
+#define VIRTIO_CONSOLE_F_UNPLUG 4 /* Can we hot-unplug ports? */
struct virtio_console_config {
/* colums of the screens */
@@ -42,6 +43,7 @@ struct virtio_console_control {
#define VIRTIO_CONSOLE_THROTTLE_PORT 4
#define VIRTIO_CONSOLE_BUFFER_LIMIT 5
#define VIRTIO_CONSOLE_CACHE_BUFFERS 6
+#define VIRTIO_CONSOLE_PORT_REMOVE 7
/*
* This struct is put in each buffer that gets passed to userspace and
--
1.6.2.5
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