chardev: add CHR_EVENT_RESIZE

Add a new chardev event, CHR_EVENT_RESIZE, which a backend should
trigger if it detects the size of the connected terminal changed.

Signed-off-by: Szymon Lukasz <noh4hss@gmail.com>
[Filip: add note that only the focused frontend gets the event]
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Filip Hejsek <filip.hejsek@gmail.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20261012-console-resize-v10-2-2c3b10d829b3@gmail.com>

backends/cryptodev-vhost-user.c

@@ -173,6 +173,7 @@ static void cryptodev_vhost_user_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

chardev/char.c

@@ -75,6 +75,7 @@ void qemu_chr_be_event(Chardev *s, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/block/vhost-user-blk.c

@@ -441,6 +441,7 @@ static void vhost_user_blk_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/char/terminal3270.c

@@ -169,6 +169,7 @@ static void chr_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/char/virtio-console.c

@@ -165,6 +165,7 @@ static void chr_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/display/vhost-user-media.c

@@ -241,6 +241,7 @@ static void vu_media_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/ipmi/ipmi_bmc_extern.c

@@ -436,6 +436,7 @@ static void chr_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/scsi/vhost-user-scsi.c

@@ -225,6 +225,7 @@ static void vhost_user_scsi_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/usb/ccid-card-passthru.c

@@ -323,6 +323,7 @@ static void ccid_card_vscard_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
     case CHR_EVENT_CLOSED:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/usb/dev-serial.c

@@ -576,6 +576,7 @@ static void usb_serial_event(void *opaque, QEMUChrEvent event)
         break;
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/usb/redirect.c

@@ -1390,6 +1390,7 @@ static void usbredir_chardev_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/virtio/vhost-user-base.c

@@ -277,6 +277,7 @@ static void vub_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

hw/virtio/vhost-user-scmi.c

@@ -215,6 +215,7 @@ static void vu_scmi_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

include/chardev/char.h

@@ -22,6 +22,12 @@ typedef enum {
     CHR_EVENT_OPENED, /* new connection established */
     CHR_EVENT_MUX_IN, /* mux-focus was set to this terminal */
     CHR_EVENT_MUX_OUT, /* mux-focus will move on */
+    CHR_EVENT_RESIZE, /*
+                       * the size of the terminal connected to
+                       * the chardev has changed.  NOTE: this event is only
+                       * sent to the focused frontend, so you should also
+                       * update the size on receiving CHR_EVENT_MUX_IN.
+                       */
     CHR_EVENT_CLOSED /* connection closed.  NOTE: currently this event
                       * is only bound to the read port of the chardev.
                       * Normally the read port and write port of a

monitor/hmp.c

@@ -1587,6 +1587,7 @@ static void monitor_event(void *opaque, QEMUChrEvent event)
         break;
 
     case CHR_EVENT_BREAK:
+    case CHR_EVENT_RESIZE:
         /* Ignored */
         break;
     }

monitor/qmp.c

@@ -663,6 +663,7 @@ static void monitor_qmp_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

net/passt.c

@@ -428,6 +428,7 @@ static void passt_vhost_user_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }

net/vhost-user.c

@@ -363,6 +363,7 @@ static void net_vhost_user_event(void *opaque, QEMUChrEvent event)
     case CHR_EVENT_BREAK:
     case CHR_EVENT_MUX_IN:
     case CHR_EVENT_MUX_OUT:
+    case CHR_EVENT_RESIZE:
         /* Ignore */
         break;
     }