Skip to content
  • Hollis Blanchard's avatar
    KVM: ppc: Implement in-kernel exit timing statistics · 73e75b41
    Hollis Blanchard authored
    
    
    Existing KVM statistics are either just counters (kvm_stat) reported for
    KVM generally or trace based aproaches like kvm_trace.
    For KVM on powerpc we had the need to track the timings of the different exit
    types. While this could be achieved parsing data created with a kvm_trace
    extension this adds too much overhead (at least on embedded PowerPC) slowing
    down the workloads we wanted to measure.
    
    Therefore this patch adds a in-kernel exit timing statistic to the powerpc kvm
    code. These statistic is available per vm&vcpu under the kvm debugfs directory.
    As this statistic is low, but still some overhead it can be enabled via a
    .config entry and should be off by default.
    
    Since this patch touched all powerpc kvm_stat code anyway this code is now
    merged and simplified together with the exit timing statistic code (still
    working with exit timing disabled in .config).
    
    Signed-off-by: default avatarChristian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
    Signed-off-by: default avatarHollis Blanchard <hollisb@us.ibm.com>
    Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
    73e75b41