Check Linux VM hardware assisted virtualization type {Xen HVM,KVM,VMware}. Based on the C program written by http://www.vpsee.com

vcheck.c

/*
 * Use CPUID opcode from EAX register to determine Linux VM Virtualization type {Xen HVM,KVM,VMware}
 * Based on the c program written by http://www.vpsee.com ;-)
 */
#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 Metal\n");

  return 0;
}