virtio_console: support console resizing
this patch uses the new hvc callback hvc_resize to set the window size
which allows to change the tty size of hvc_console via a hvc_resize
function.
I have added a new feature bit VIRTIO_CONSOLE_F_SIZE. The driver will
change the window size on tty open and via the config_changed callback
of the transport. Currently lguest and kvm_s390 have not implemented this
callback, but the callback can be implemented at a later point in time.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index fb57f67..0587b66 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -695,6 +695,7 @@
hp->ws = ws;
schedule_work(&hp->tty_resize);
}
+EXPORT_SYMBOL_GPL(hvc_resize);
/*
* This kthread is either polling or interrupt driven. This is determined by
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index 3fb0d2c..ff6f5a4 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -138,12 +138,33 @@
}
/*
+ * virtio console configuration. This supports:
+ * - console resize
+ */
+static void virtcons_apply_config(struct virtio_device *dev)
+{
+ struct winsize ws;
+
+ if (virtio_has_feature(dev, VIRTIO_CONSOLE_F_SIZE)) {
+ dev->config->get(dev,
+ offsetof(struct virtio_console_config, cols),
+ &ws.ws_col, sizeof(u16));
+ dev->config->get(dev,
+ offsetof(struct virtio_console_config, rows),
+ &ws.ws_row, sizeof(u16));
+ hvc_resize(hvc, ws);
+ }
+}
+
+/*
* we support only one console, the hvc struct is a global var
- * There is no need to do anything
+ * We set the configuration at this point, since we now have a tty
*/
static int notifier_add_vio(struct hvc_struct *hp, int data)
{
hp->irq_requested = 1;
+ virtcons_apply_config(vdev);
+
return 0;
}
@@ -234,11 +255,18 @@
{ 0 },
};
+static unsigned int features[] = {
+ VIRTIO_CONSOLE_F_SIZE,
+};
+
static struct virtio_driver virtio_console = {
+ .feature_table = features,
+ .feature_table_size = ARRAY_SIZE(features),
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = virtcons_probe,
+ .config_changed = virtcons_apply_config,
};
static int __init init(void)
diff --git a/include/linux/virtio_console.h b/include/linux/virtio_console.h
index 19a0da0..7615ffc 100644
--- a/include/linux/virtio_console.h
+++ b/include/linux/virtio_console.h
@@ -7,6 +7,17 @@
/* The ID for virtio console */
#define VIRTIO_ID_CONSOLE 3
+/* Feature bits */
+#define VIRTIO_CONSOLE_F_SIZE 0 /* Does host provide console size? */
+
+struct virtio_console_config {
+ /* colums of the screens */
+ __u16 cols;
+ /* rows of the screens */
+ __u16 rows;
+} __attribute__((packed));
+
+
#ifdef __KERNEL__
int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int));
#endif /* __KERNEL__ */
