NAME

kvmstat — report KVM statistics

SYNOPSIS

kvmstat [interval [count]]

DESCRIPTION

kvmstat reports the activity of running KVM virtual machines and their exit activity, injected interrupts, emulations, and more, on a per virtual CPU basis.

kvmstat should be used when trying to get a rough sense of guest activity from the hypervisor's perspective, and allows one to understand from a low-level perspective, what kind of activity is going on inside of the virtual machine. In addition, kvmstat is useful for diagnosing reports of pathological or faulty behavior inside of guests. While there is no expected range of values for the fields displayed as that varies with the use of virtual machines, if all of the virtual CPUs for a given virtual machine are consistently zero, then that may indicate that a problem has occurred, for example, a panic inside of the guest or a bug in the hypervisor.

If no operands are specified, then kvmstat will display statistics every second until the program is terminated.

Output Fields

Every interval kvmstat will report data with the following fields:

pid: Identifier of the process controlling the virtual CPU.
vcpu: Virtual CPU identifier relative to its virtual machine.
exits: Count of all virtual machine exits for the virtual CPU over interval.
haltx: Count of virtual machine exits due to the guest executing the HLT instruction for the virtual CPU over interval.
irqx: Count of virtual machine exits due to a pending external interrupt arriving on the physical CPU that the virtual CPU was actively running on over interval.
irqwx: Count of virtual machine exits due to an open interrupt window on the virtual CPU over interval.
iox: Count of virtual machine exits due to the execution of an I/O instruction, such as inb, on the virtual CPU over interval.
mmiox: Count of virtual machine exits due to performing memory mapped I/O on the virtual CPU over interval.
irqs: Count of interrupts injected into the virtual CPU over interval.
emul: Count of instructions the hypervisor had to emulate on behalf of the guest virtual CPU over interval.
eptv: Count of extended page table violations serviced on the virtual CPU over interval.

OPERANDS

The following operands are supported:

count: Specifies the number of times that the statistics are repeated. If not specified, kvmstat will continue until it is terminated.
interval: Specifies the number of seconds between reports of statistics. If not specified, reports are generated every second.

STABILITY

The arguments are committed, while the output format is Not an interface.