2.2. Virtual Performance Monitoring Unit (vPMU)

The virtual performance monitoring unit (vPMU) displays statistics which indicate how a guest virtual machine is functioning.

The virtual performance monitoring unit allows users to identify sources of possible performance problems in their guest virtual machines. The vPMU is based on Intel's PMU (Performance Monitoring Units) and can only be used on Intel machines.

This feature is only supported with guest virtual machines running Red Hat Enterprise Linux 6 or Red Hat Enterprise Linux 7 and is disabled by default.

To verify if the vPMU is supported on your system, check for the arch_perfmon flag on the host CPU by running:

# cat /proc/cpuinfo|grep arch_perfmon

To enable the vPMU, specify the cpu mode in the guest XML as host-passthrough:

# virsh dumpxml guest_name |grep "cpu mode"
<cpu mode='host-passthrough'>

After the vPMU is enabled, display a virtual machine's performance statistics by running the perf command from the guest virtual machine.