the root cause is that the qemu cursor array is hardcoded to 256 bytes, while the sato use cursor of the size 64*64=4096, thus lead buffer overflow and abnormal mouse.
A qemu patch is introduced to dynamically allocate qemu cursor array to fix this issue. BTW, qemu upstream already redesign the cursor interface and implementation, and this issue does not occur in upstream, so no need to push this patch to upstream. and when upgrade the qemu, this patch can be safely removed.
