Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Tested-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
HIDState *s = opaque;
hid_set_next_idle(s);
+
+ if (s->n == QUEUE_LENGTH && (s->kind == HID_TABLET ||
+ s->kind == HID_MOUSE)) {
+ /*
+ * Handle ptr device migration from old qemu with full queue.
+ *
+ * Throw away everything but the last event, so we propagate
+ * at least the current button state to the guest. Also keep
+ * current position for the tablet, signal "no motion" for the
+ * mouse.
+ */
+ HIDPointerEvent evt;
+ evt = s->ptr.queue[(s->head+s->n) & QUEUE_MASK];
+ if (s->kind == HID_MOUSE) {
+ evt.xdx = 0;
+ evt.ydy = 0;
+ }
+ s->ptr.queue[0] = evt;
+ s->head = 0;
+ s->n = 1;
+ }
return 0;
}