Using the KVM API

I initially thought that this number '0x3f8' has a special significance for kvm api, as in, kvm would recognize this address as an memory mapped I/O or some other special address. The truth is that KVM exits due to 'out' opcode, and not because of the address. In the host, we then check the 1st operand of this 'out' opcode matches the value we gave, '0x3f8' in this case. We can have any other number (as long as it is 1 byte long) as operand, thus even 'out 0x4000, al', or 'out 0x0000, al' (intel syntax) would work just fine.