How to call c++ library in qemu

[沈梦姣]

Hello,
With qemu I’m trying to call a c++ api which is from a open source project 
which doesn’t have c interface, so I make a wrapper of that API and compile it 
to dynamic lib(dll), and qemu will call the wrapper c api and link that lib. 
But I got error when try to run, saying qemu can’t find some entry point 
located in the lib. So I’m wandering is there any special for qemu call c++ 
lib? Thanks in advance!