• Wanpeng Li's avatar
    KVM: LAPIC: Trace LAPIC timer expiration on every vmentry · e0ac5351
    Wanpeng Li authored
    In commit ec0671d5 ("KVM: LAPIC: Delay trace_kvm_wait_lapic_expire
    tracepoint to after vmexit", 2019-06-04), trace_kvm_wait_lapic_expire
    was moved after guest_exit_irqoff() because invoking tracepoints within
    kvm_guest_enter/kvm_guest_exit caused a lockdep splat.
    
    These days this is not necessary, because commit 87fa7f3e ("x86/kvm:
    Move context tracking where it belongs", 2020-07-09) restricted
    the RCU extended quiescent state to be closer to vmentry/vmexit.
    Moving the tracepoint back to __kvm_wait_lapic_expire is more accurate,
    because it will be reported even if vcpu_enter_guest causes multiple
    vmentries via the IPI/Timer fast paths, and it allows the removal of
    advance_expire_delta.
    Signed-off-by: default avatarWanpeng Li <wanpengli@tencent.com>
    Message-Id: <1650961551-38390-1-git-send-email-wanpengli@tencent.com>
    Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
    e0ac5351
lapic.c 76.6 KB