#!/usr/bin/python
# check if a linux system running on a virtual machine (openvz/xen pv/uml)

import sys, os

def main():
    if os.getuid() != 0:
        print "must be run as root"
        sys.exit(0)

    # check OpenVZ/Virtuozzo
    if os.path.exists("/proc/vz"):
        if not os.path.exists("/proc/bc"):
            print "openvz container"
        else:
            print "openvz node"

    # check Xen
    if os.path.exists("/proc/xen/capabilities"):
        if (os.path.getsize("/proc/xen/capabilities") > 0):
            print "xen dom0"
        else:
            print "xen domU"

    # check User Mode Linux (UML)
    f = open("/proc/cpuinfo", "r"); t = f.read(); f.close()
    if (t.find("UML") > 0):
        print "uml"

if __name__=="__main__":
    main()

/*
 * check if a linux system running on a virtual machine (vmware/xen hvm/kvm)
 */
#include stdio.h
#include string.h

#define HYPERVISOR_INFO 0x40000000

#define CPUID(idx, eax, ebx, ecx, edx) /
    asm volatile ( /
        "test %1,%1 ; jz 1f ; ud2a ; .ascii /"xen/" ; 1: cpuid" /
        : "=b" (*ebx), "=a" (*eax), "=c" (*ecx), "=d" (*edx) /
        : "0" (idx) );

int main(void)
{
        unsigned int eax, ebx, ecx, edx;
        char string[13];

        CPUID(HYPERVISOR_INFO, &eax, &ebx, &ecx, &edx);
        *(unsigned int *)(string+0) = ebx;
        *(unsigned int *)(string+4) = ecx;
        *(unsigned int *)(string+8) = edx;

        string[12] = 0;
        if (strncmp(string, "XenVMMXenVMM", 12) == 0) {
                printf("xen hvm/n");
        } else if (strncmp(string, "VMwareVMware", 12) == 0) {
                printf("vmware/n");
        } else if (strncmp(string, "KVMKVMKVM", 12) == 0) {
                printf("kvm/n");
        } else
                printf("bare hardware/n");

        return 0;
}