Commit ce1a5e60 authored by David Matlack's avatar David Matlack Committed by Paolo Bonzini

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: default avatarDavid Matlack <dmatlack@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 09a0c3f1
......@@ -5,6 +5,7 @@
#include <asm/vmx.h>
#include <asm/svm.h>
#include <asm/clocksource.h>
#include <asm/pvclock-abi.h>
#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
......
......@@ -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));
......
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