The host can set a name for ports so that they're easily discoverable instead of going by the /dev/vportNpn naming. This attribute will be placed in /sys/class/vportdevN/vportNpn/name. udev scripts can then create symlinks to the port using the name.
Signed-off-by: Amit Shah <[email protected]> --- drivers/char/virtio_console.c | 58 ++++++++++++++++++++++++++++++++++++++++ include/linux/virtio_console.h | 1 + 2 files changed, 59 insertions(+), 0 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 3a305f8..d0bdc18 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -163,6 +163,9 @@ struct port { */ struct console cons; + /* The 'name' of the port that we expose via sysfs properties */ + char *name; + /* The 'id' to identify the port with the Host */ u32 id; @@ -745,10 +748,14 @@ static void fill_receive_queue(struct ports_device *portdev) spin_unlock(&portdev->read_list_lock); } +static struct attribute_group port_attribute_group; + /* Any private messages that the Host and Guest want to share */ static void handle_control_message(struct port *port, struct port_buffer *buf) { struct virtio_console_control *cpkt; + size_t name_size; + int err; cpkt = (struct virtio_console_control *)(buf->buf + buf->offset); @@ -775,6 +782,35 @@ static void handle_control_message(struct port *port, struct port_buffer *buf) port->host_connected = cpkt->value; wake_up_interruptible(&port->waitqueue); break; + case VIRTIO_CONSOLE_PORT_NAME: + /* + * Skip the size of the header and the cpkt to get the size + * of the name that was sent + */ + name_size = buf->len - buf->offset - sizeof(*cpkt) + 1; + + port->name = kmalloc(name_size, GFP_KERNEL); + if (!port->name) { + dev_err(port->dev, + "not enough space to store port name\n"); + break; + } + strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt), + name_size - 1); + port->name[name_size - 1] = 0; + + /* + * Since we only have one sysfs attribute, 'name', + * create it only if we have a name for the port. + */ + err = sysfs_create_group(&port->dev->kobj, + &port_attribute_group); + if (err) + dev_err(port->dev, + "error creating sysfs device attributes, ret = %d\n", + err); + + break; } } @@ -902,6 +938,28 @@ static void tx_intr(struct virtqueue *vq) spin_unlock_irqrestore(&portdev->write_list_lock, flags); } +static ssize_t show_port_name(struct device *dev, + struct device_attribute *attr, char *buffer) +{ + struct port *port; + + port = dev_get_drvdata(dev); + + return sprintf(buffer, "%s\n", port->name); +} + +static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL); + +static struct attribute *port_sysfs_entries[] = { + &dev_attr_name.attr, + NULL +}; + +static struct attribute_group port_attribute_group = { + .name = NULL, /* put in device directory */ + .attrs = port_sysfs_entries, +}; + static int __devinit add_port(struct ports_device *portdev, u32 id) { struct port *port; diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h index 14af53d..d65fdb5 100644 --- a/include/linux/virtio_console.h +++ b/include/linux/virtio_console.h @@ -37,6 +37,7 @@ struct virtio_console_control { #define VIRTIO_CONSOLE_CONSOLE_PORT 1 #define VIRTIO_CONSOLE_RESIZE 2 #define VIRTIO_CONSOLE_PORT_OPEN 3 +#define VIRTIO_CONSOLE_PORT_NAME 4 /* * This struct is put at the start of each buffer that gets passed to -- 1.6.2.5 _______________________________________________ Virtualization mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/virtualization
