Xorg server hangs when using xfig and typing a text with space:
#0 qxl_wait_for_io_command (qxl=<value optimized out>) at qxl_io.c:47
#1 0x00007f826a49a299 in qxl_download_box (surface=0x221d030, x1=231, y1=259,
x2=<value optimized out>, y2=<value optimized out>) at qxl_surface.c:143
while (!(ram_header->int_pending & QXL_INTERRUPT_IO_CMD))
usleep (1);
The QXL driver is calling QXL_IO_UPDATE_AREA with an empty area. This
is a guest bug. The call is async and no ack is sent back on guest
bug, so the X server will hang. The driver should be improved to avoid
this situation and also to abort on QXL_INTERRUPT_ERROR. This will be
a different patch series for the driver. However, it is simple enough
to keep qemu running on empty areas update, which is what this patch
provides.
https://bugzilla.redhat.com/show_bug.cgi?id=1151363
---
hw/display/qxl.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 93b3518..b540dd6 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -1591,6 +1591,11 @@ async_common:
qxl_set_guest_bug(d,
"QXL_IO_UPDATE_AREA: invalid area (%ux%u)x(%ux%u)\n",
update.left, update.top, update.right, update.bottom);
+ if (update.left == update.right || update.top == update.bottom) {
+ /* old drivers may provide empty area, keep going */
+ qxl_clear_guest_bug(d);
+ goto cancel_async;
+ }
break;
}
if (async == QXL_ASYNC) {
--
1.9.3
