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/virtio-ports/vportNpn/name. udev scripts can then
create symlinks to the port using the name.
Signed-off-by: Amit Shah <amit.s...@redhat.com>
---
drivers/char/virtio_console.c | 57 ++++++++++++++++++++++++++++++++++++++++
include/linux/virtio_console.h | 1 +
2 files changed, 58 insertions(+), 0 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index abab15f..4fefa4d 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -176,6 +176,9 @@ struct port {
/* A waitqueue for poll() or blocking read operations */
wait_queue_head_t waitqueue;
+ /* The 'name' of the port that we expose via sysfs properties */
+ char *name;
+
/* The 'id' to identify the port with the Host */
u32 id;
@@ -765,12 +768,36 @@ int init_port_console(struct port *port)
return 0;
}
+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,
+};
+
/* Any private messages that the Host and Guest want to share */
static void handle_control_message(struct ports_device *portdev,
struct port_buffer *buf)
{
struct virtio_console_control *cpkt;
struct port *port;
+ size_t name_size;
+ int err;
cpkt = (struct virtio_console_control *)(buf->buf + buf->offset);
@@ -805,6 +832,35 @@ static void handle_control_message(struct ports_device
*portdev,
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 %d creating sysfs device attributes\n",
+ err);
+
+ break;
}
}
@@ -901,6 +957,7 @@ static int add_port(struct ports_device *portdev, u32 id)
port->portdev = portdev;
port->id = id;
+ port->name = NULL;
port->inbuf = NULL;
port->cons.hvc = NULL;
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index 9952b02..8e85045 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -40,6 +40,7 @@ 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 data buffer that gets
--
1.6.2.5
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