Read the documentation in qemu-doc.html or on http://wiki.qemu-project.org - QEMU team
Benjamin Herrenschmidt
authored
In order to remove the logic for detecting supported shared
pixmap formats from device models, make qemu_default_pixman_format()
capable for failing by returning 0 which is not a possible format
value rather than asserting.
Signed-off-by: 
Benjamin Herrenschmidt <benh@kernel.crashing.org>