Monitor/Trap Software Interrupt INT 80h (System Call) with x86/Intel Virtualization Technology

In an unix-like system, before syscall/sysret and/or sysenter/sysexit instructions were introduced by x86/Intel processors, software interrupt "INT 80h" was used as system call interface. Unlike my previous post, this one is going to talk about how to monitor this old type system call.

Yet Another Solution to Monitor/Trap SYSCALL with Virtualization Technology (x86)

This article describes an idea to monitor SYSCALL with x86 Hardware Virtualization Technology. It doesn't require visible guest code/data modification, so that in some cases, even Kernel Patch Protection (e.g. Windows x64 PatchGuard) cannot detect it. Here the SYSCALL could also be SYSENTER or INT 80h for system calls.