Check Processor VT Support - Linux Tip

Understanding Virtualization Technology (VT) Support

Virtualization Technology (VT) represents a collection of enhancements integrated into modern processors. These improvements facilitate enhanced performance when running virtual machines. This is achieved by delegating certain processing tasks to specialized CPU extensions.

Both AMD and Intel manufacture processors equipped with this technology. Determining whether your specific system is capable of utilizing VT, however, requires a simple verification process.

Checking for VT Support

To ascertain VT compatibility, you'll need to examine the contents of the /proc/cpuinfo file. Specifically, focus on the 'flags' section, looking for one of two key indicators:

• vmx - (Intel processors)
• svm - (AMD processors)

A quick and efficient method to check for these flags is to employ the grep command. Execute the following command in your terminal:

egrep '(vmx|svm)' /proc/cpuinfo

If your system supports VT, either 'vmx' or 'svm' will be present within the displayed list of flags. Systems with multiple processors will show separate sections for each.

For example, a typical output might resemble this:

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 syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm
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 syscall nx lm constant_tsc pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm

BIOS Considerations and VMware Configuration

Even if your processor supports VT, as indicated by the cpuinfo flags, the technology might be disabled within your computer’s BIOS settings. Therefore, it’s crucial to verify its status in the BIOS to ensure it hasn’t been inadvertently deactivated.

VT is a prerequisite for running 64-bit virtual machines using VMware Server for Linux. Consequently, successful execution of 64-bit guests implies that VT is enabled.

By default, 32-bit VT is not activated within VMware Server. To enable it for a specific virtual machine, you must add the following line to the corresponding *.vmx configuration file:

monitor_control.vt32 = TRUE

However, VMware advises against utilizing VT for 32-bit virtual machines, citing potential performance degradation as a result.