Checking the guest's environment

ARM platforms

On ARM platforms, check the model property in the Flattened Device Tree (FDT) that describes the guest's system. If this property is set with QVM-v8A, then the system is hosted in a QNX hypervisor VM.

x86 platforms

For x86 platforms, see your hardware documentation to learn which CPUID register bit your guest needs to check to know if it is running in a hypervisor, and where in the register it needs to look for the VM ID string. The ID string for QNX hypervisor VMs is “QNXQVMBS”.

Below is an example of C code that a QNX guest might use to check if it is running in a QNX hypervisor on an x86 platform:

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <arpa/inet.h>
 
int cpuid(uint32_t id, uint32_t *regs) {
       asm volatile ("cpuid"
             : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3])
             : "a" (id), "c" (0));
       return 0;
}
 
static const char * const qnxstr = "QNXQVMBS";
 
int main(int argc, char *argv[])
{
       uint32_t regs[4];
 
       cpuid(1, regs);
       if ((regs[2] & (1 << 31)) == 0) {
             puts("We are not running in a hypervisor");
             return 1; /* not a hypervisor */
       }
 
       /* It is a hypervisor, but is it OUR hypervisor? */
       cpuid(0x40000000, regs);
       regs[1] = htonl(regs[1]);
       regs[2] = htonl(regs[2]);
       if (memcmp(&regs[1], qnxstr, 4) != 0 || memcmp(&regs[2], qnxstr + 4, 4) != 0) {
             puts("This is a hypervisor but not a QNX hypervisor system");
             return 1; /* not ours :( */
       }
 
       /* It is a QNX hypervisor. */
       puts("This is a QNX QVM hypervisor system");

       return 0;
}

Linux and Android guests

You can adapt the C code above for Linux and Android guests on x86, or run the cpuid utility.