diff options
| -rw-r--r-- | drivers/char/virtio_console.c | 65 | ||||
| -rw-r--r-- | include/linux/virtio_console.h | 1 |
2 files changed, 64 insertions, 2 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 7c53f58c87b..9f20fda9c56 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -783,6 +783,36 @@ static struct attribute_group port_attribute_group = { .attrs = port_sysfs_entries, }; +/* Remove all port-specific data. */ +static int remove_port(struct port *port) +{ + spin_lock_irq(&port->portdev->ports_lock); + list_del(&port->list); + spin_unlock_irq(&port->portdev->ports_lock); + + if (is_console_port(port)) { + spin_lock_irq(&pdrvdata_lock); + list_del(&port->cons.list); + spin_unlock_irq(&pdrvdata_lock); + hvc_remove(port->cons.hvc); + } + if (port->guest_connected) + send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); + + while (port->in_vq->vq_ops->detach_unused_buf(port->in_vq)) + ; + + sysfs_remove_group(&port->dev->kobj, &port_attribute_group); + device_destroy(pdrvdata.class, port->dev->devt); + cdev_del(&port->cdev); + + discard_port_data(port); + kfree(port->name); + + kfree(port); + return 0; +} + /* Any private messages that the Host and Guest want to share */ static void handle_control_message(struct ports_device *portdev, struct port_buffer *buf) @@ -854,6 +884,32 @@ static void handle_control_message(struct ports_device *portdev, err); 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). + * + */ + remove_port(port); + break; } } @@ -1078,12 +1134,17 @@ static void config_work_handler(struct work_struct *work) /* * Port 0 got hot-added. Since we already did all the * other initialisation for it, just tell the Host - * that the port is ready. + * that the port is ready if we find the port. In + * case the port was hot-removed earlier, we call + * add_port to add the port. */ struct port *port; port = find_port_by_id(portdev, 0); - send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); + if (!port) + add_port(portdev, 0); + else + send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); return; } if (virtconconf.nr_ports > portdev->config.max_nr_ports) { diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index 1ebf007812a..ae4f039515b 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -41,6 +41,7 @@ struct virtio_console_control { #define VIRTIO_CONSOLE_RESIZE 2 #define VIRTIO_CONSOLE_PORT_OPEN 3 #define VIRTIO_CONSOLE_PORT_NAME 4 +#define VIRTIO_CONSOLE_PORT_REMOVE 5 #ifdef __KERNEL__ int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)); |