[PATCH v8 10/12] qmp: add chardev-window-size-changed command

[Filip Hejsek <filip.hejsek@gmail.com>]

From: Szymon Lukasz <noh4hss@gmail.com>

The managment software can use this command to notify QEMU about the
size of the terminal connected to a chardev, QEMU can then forward this
information to the guest if the chardev is connected to a virtio console
device.

Signed-off-by: Szymon Lukasz <noh4hss@gmail.com>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
[Filip: rename command, change documentation]
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
---
 chardev/char.c | 14 ++++++++++++++
 qapi/char.json | 31 +++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/chardev/char.c b/chardev/char.c
index 8c8386e5b5..fe513ae962 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -1347,6 +1347,20 @@ bool qmp_add_client_char(int fd, bool has_skipauth, bool skipauth,
     return true;
 }
 
+void qmp_chardev_window_size_changed(const char *id, uint16_t cols,
+                                     uint16_t rows, Error **errp)
+{
+    Chardev *chr;
+
+    chr = qemu_chr_find(id);
+    if (chr == NULL) {
+        error_setg(errp, "Chardev '%s' not found", id);
+        return;
+    }
+
+    qemu_chr_resize(chr, cols, rows);
+}
+
 /*
  * Add a timeout callback for the chardev (in milliseconds), return
  * the GSource object created. Please use this to add timeout hook for
diff --git a/qapi/char.json b/qapi/char.json
index abaccefa97..2037836172 100644
--- a/qapi/char.json
+++ b/qapi/char.json
@@ -891,6 +891,37 @@
 { 'command': 'chardev-send-break',
   'data': { 'id': 'str' } }
 
+##
+# @chardev-window-size-changed:
+#
+# Notifies a chardev about the current size of the terminal connected
+# to this chardev.  The information will be forwarded to the guest if
+# the chardev is connected to a virtio console device.
+#
+# The initial size is 0x0, which should be interpreted as an unknown
+# size.
+#
+# Some backends detect the terminal size automatically, in which case
+# the size may unpredictably revert to the detected one at any time.
+#
+# @id: the chardev's ID
+#
+# @cols: the number of columns
+#
+# @rows: the number of rows
+#
+# Since: 11.2
+#
+# .. qmp-example::
+#
+#     -> { "execute": "chardev-window-size-changed", "arguments": { "id": "foo", "cols": 80, "rows": 24 } }
+#     <- { "return": {} }
+##
+{ 'command': 'chardev-window-size-changed',
+  'data': { 'id': 'str',
+            'cols': 'uint16',
+            'rows': 'uint16' } }
+
 ##
 # @VSERPORT_CHANGE:
 #

-- 
2.55.0