If the machine supports para virtual guests, then you should see a “pae” flag in /proc/info. This means – the machine has PAE support and can run para virtual guests.

[root@unixfoo root]# cat /proc/cpuinfo | grep pae
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm nx lm
[root@unixfoo root]#

If there is no output for the above command, then the machine is not capable of running a para-virtualized guest.

To run fully virtualized guests, host CPU support is needed. This is typically referred to as Intel VT, or AMD-V. To check for Intel VT support look for the ‘vmx’ flag, or for AMD-V support check for ‘svm’ flag:

Intel

# grep vmx /proc/cpuinfo 
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 cx16 xtpr lahf_lm
AMD # grep svm /proc/cpuinfo
flags : fpu tsc msr pae mce cx8 apic mtrr mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dnowext 3dnow pni cx16 lahf_lm cmp_legacy svm cr8_legacy


If you have the ‘svm’ or ‘vmx’ flags, then your CPU is capable of fully-virt.