[PATCH v6 16/17] KVM: SVM: Add AVIC doorbell tracepoint

Suravee Suthikulpanit
2022-05-19T10:29:04Z

Add a tracepoint to track number of doorbells being sent
to signal a running vCPU to process IRQ after being injected.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
arch/x86/kvm/svm/avic.c | 4 +++-
arch/x86/kvm/trace.h | 18 ++++++++++++++++++
arch/x86/kvm/x86.c | 1 +
3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 9c439a32c343..2a9eb419bdb9 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -324,8 +324,10 @@ void avic_ring_doorbell(struct kvm_vcpu *vcpu)
*/
int cpu = READ_ONCE(vcpu->cpu);

- if (cpu != get_cpu())
+ if (cpu != get_cpu()) {
wrmsrl(MSR_AMD64_SVM_AVIC_DOORBELL, kvm_cpu_get_apicid(cpu));
+ trace_kvm_avic_doorbell(vcpu->vcpu_id, kvm_cpu_get_apicid(cpu));
+ }
put_cpu();
}

diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index de4762517569..a47bb0fdea70 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1479,6 +1479,24 @@ TRACE_EVENT(kvm_avic_kick_vcpu_slowpath,
__entry->icrh, __entry->icrl, __entry->index)
);

+TRACE_EVENT(kvm_avic_doorbell,
+ TP_PROTO(u32 vcpuid, u32 apicid),
+ TP_ARGS(vcpuid, apicid),
+
+ TP_STRUCT__entry(
+ __field(u32, vcpuid)
+ __field(u32, apicid)
+ ),
+
+ TP_fast_assign(
+ __entry->vcpuid = vcpuid;
+ __entry->apicid = apicid;
+ ),
+
+ TP_printk("vcpuid=%u, apicid=%u",
+ __entry->vcpuid, __entry->apicid)
+);
+
TRACE_EVENT(kvm_hv_timer_state,
TP_PROTO(unsigned int vcpu_id, unsigned int hv_timer_in_use),
TP_ARGS(vcpu_id, hv_timer_in_use),
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0febaca80feb..d013f6fc2e33 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -13095,6 +13095,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_incomplete_ipi);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_ga_log);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_kick_vcpu_slowpath);
+EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_doorbell);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_apicv_accept_irq);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_enter);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_vmgexit_exit);
--
2.25.1