From ce1a5e60a62f21a6b5ad3e1dee60c10f0cb2aa37 Mon Sep 17 00:00:00 2001 From: David Matlack Date: Wed, 5 Nov 2014 11:46:42 -0800 Subject: [PATCH] kvm: x86: add trace event for pvclock updates The new trace event records: * the id of vcpu being updated * the pvclock_vcpu_time_info struct being written to guest memory This is useful for debugging pvclock bugs, such as the bug fixed by "[PATCH] kvm: x86: Fix kvm clock versioning.". Signed-off-by: David Matlack Signed-off-by: Paolo Bonzini --- arch/x86/kvm/trace.h | 37 +++++++++++++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 2 ++ 2 files changed, 39 insertions(+) diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h index 6b06ab8..c2a34bb 100644 --- a/arch/x86/kvm/trace.h +++ b/arch/x86/kvm/trace.h @@ -5,6 +5,7 @@ #include #include #include +#include #undef TRACE_SYSTEM #define TRACE_SYSTEM kvm @@ -877,6 +878,42 @@ TRACE_EVENT(kvm_ple_window, #define trace_kvm_ple_window_shrink(vcpu_id, new, old) \ trace_kvm_ple_window(false, vcpu_id, new, old) +TRACE_EVENT(kvm_pvclock_update, + TP_PROTO(unsigned int vcpu_id, struct pvclock_vcpu_time_info *pvclock), + TP_ARGS(vcpu_id, pvclock), + + TP_STRUCT__entry( + __field( unsigned int, vcpu_id ) + __field( __u32, version ) + __field( __u64, tsc_timestamp ) + __field( __u64, system_time ) + __field( __u32, tsc_to_system_mul ) + __field( __s8, tsc_shift ) + __field( __u8, flags ) + ), + + TP_fast_assign( + __entry->vcpu_id = vcpu_id; + __entry->version = pvclock->version; + __entry->tsc_timestamp = pvclock->tsc_timestamp; + __entry->system_time = pvclock->system_time; + __entry->tsc_to_system_mul = pvclock->tsc_to_system_mul; + __entry->tsc_shift = pvclock->tsc_shift; + __entry->flags = pvclock->flags; + ), + + TP_printk("vcpu_id %u, pvclock { version %u, tsc_timestamp 0x%llx, " + "system_time 0x%llx, tsc_to_system_mul 0x%x, tsc_shift %d, " + "flags 0x%x }", + __entry->vcpu_id, + __entry->version, + __entry->tsc_timestamp, + __entry->system_time, + __entry->tsc_to_system_mul, + __entry->tsc_shift, + __entry->flags) +); + #endif /* _TRACE_KVM_H */ #undef TRACE_INCLUDE_PATH diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8bf37d0..f85da5c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1661,6 +1661,8 @@ static int kvm_guest_time_update(struct kvm_vcpu *v) vcpu->hv_clock.flags = pvclock_flags; + trace_kvm_pvclock_update(v->vcpu_id, &vcpu->hv_clock); + kvm_write_guest_cached(v->kvm, &vcpu->pv_time, &vcpu->hv_clock, sizeof(vcpu->hv_clock)); -- 2.7.4