• Glauber Costa's avatar
    KVM: Steal time implementation · c9aaa895
    Glauber Costa authored
    To implement steal time, we need the hypervisor to pass the guest
    information about how much time was spent running other processes
    outside the VM, while the vcpu had meaningful work to do - halt
    time does not count.
    This information is acquired through the run_delay field of
    delayacct/schedstats infrastructure, that counts time spent in a
    runqueue but not running.
    Steal time is a per-cpu information, so the traditional MSR-based
    infrastructure is used. A new msr, KVM_MSR_STEAL_TIME, holds the
    memory area address containing information about steal time
    This patch contains the hypervisor part of the steal time infrasructure,
    and can be backported independently of the guest portion.
    [avi, yongjie: export delayacct_on, to avoid build failures in some configs]
    Signed-off-by: default avatarGlauber Costa <glommer@redhat.com>
    Tested-by: default avatarEric B Munson <emunson@mgebm.net>
    CC: Rik van Riel <riel@redhat.com>
    CC: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
    CC: Peter Zijlstra <peterz@infradead.org>
    CC: Anthony Liguori <aliguori@us.ibm.com>
    Signed-off-by: default avatarYongjie Ren <yongjie.ren@intel.com>
    Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
delayacct.c 5.01 KB