KVM: x86: Differentiate Soft vs. Hard IRQs vs. reinjected in tracepoint

In the IRQ injection tracepoint, differentiate between Hard IRQs and Soft
"IRQs", i.e. interrupts that are reinjected after incomplete delivery of
a software interrupt from an INTn instruction.  Tag reinjected interrupts
as such, even though the information is usually redundant since soft
interrupts are only ever reinjected by KVM.  Though rare in practice, a
hard IRQ can be reinjected.

Signed-off-by: Sean Christopherson <seanjc@google.com>
[MSS: change "kvm_inj_virq" event "reinjected" field type to bool]
Signed-off-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Message-Id: <9664d49b3bd21e227caa501cff77b0569bebffe2.1651440202.git.maciej.szmigiero@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

4 files changed, 18 insertions, 11 deletions

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 6248967d4a77..0f4d38e5ceab 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3435,7 +3435,7 @@ static void svm_inject_nmi(struct kvm_vcpu *vcpu)
 	++vcpu->stat.nmi_injections;
 }
 
-static void svm_inject_irq(struct kvm_vcpu *vcpu)
+static void svm_inject_irq(struct kvm_vcpu *vcpu, bool reinjected)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 	u32 type;
@@ -3449,7 +3449,8 @@ static void svm_inject_irq(struct kvm_vcpu *vcpu)
 		type = SVM_EVTINJ_TYPE_INTR;
 	}
 
-	trace_kvm_inj_virq(vcpu->arch.interrupt.nr);
+	trace_kvm_inj_virq(vcpu->arch.interrupt.nr,
+			   vcpu->arch.interrupt.soft, reinjected);
 	++vcpu->stat.irq_injections;
 
 	svm->vmcb->control.event_inj = vcpu->arch.interrupt.nr |
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index 385436d12024..fd28dd40b813 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -333,18 +333,24 @@ TRACE_EVENT_KVM_EXIT(kvm_exit);
  * Tracepoint for kvm interrupt injection:
  */
 TRACE_EVENT(kvm_inj_virq,
-	TP_PROTO(unsigned int irq),
-	TP_ARGS(irq),
+	TP_PROTO(unsigned int vector, bool soft, bool reinjected),
+	TP_ARGS(vector, soft, reinjected),
 
 	TP_STRUCT__entry(
-		__field(	unsigned int,	irq		)
+		__field(	unsigned int,	vector		)
+		__field(	bool,		soft		)
+		__field(	bool,		reinjected	)
 	),
 
 	TP_fast_assign(
-		__entry->irq		= irq;
+		__entry->vector		= vector;
+		__entry->soft		= soft;
+		__entry->reinjected	= reinjected;
 	),
 
-	TP_printk("irq %u", __entry->irq)
+	TP_printk("%s 0x%x%s",
+		  __entry->soft ? "Soft/INTn" : "IRQ", __entry->vector,
+		  __entry->reinjected ? " [reinjected]" : "")
 );
 
 #define EXS(x) { x##_VECTOR, "#" #x }
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index e1aa14743cdb..9714ae95589f 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4573,13 +4573,13 @@ static void vmx_enable_nmi_window(struct kvm_vcpu *vcpu)
 	exec_controls_setbit(to_vmx(vcpu), CPU_BASED_NMI_WINDOW_EXITING);
 }
 
-static void vmx_inject_irq(struct kvm_vcpu *vcpu)
+static void vmx_inject_irq(struct kvm_vcpu *vcpu, bool reinjected)
 {
 	struct vcpu_vmx *vmx = to_vmx(vcpu);
 	uint32_t intr;
 	int irq = vcpu->arch.interrupt.nr;
 
-	trace_kvm_inj_virq(irq);
+	trace_kvm_inj_virq(irq, vcpu->arch.interrupt.soft, reinjected);
 
 	++vcpu->stat.irq_injections;
 	if (vmx->rmode.vm86_active) {
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c9f3ad89bf4c..501606e02688 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9448,7 +9448,7 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit)
 			static_call(kvm_x86_inject_nmi)(vcpu);
 			can_inject = false;
 		} else if (vcpu->arch.interrupt.injected) {
-			static_call(kvm_x86_inject_irq)(vcpu);
+			static_call(kvm_x86_inject_irq)(vcpu, true);
 			can_inject = false;
 		}
 	}
@@ -9539,7 +9539,7 @@ static int inject_pending_event(struct kvm_vcpu *vcpu, bool *req_immediate_exit)
 			goto out;
 		if (r) {
 			kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu), false);
-			static_call(kvm_x86_inject_irq)(vcpu);
+			static_call(kvm_x86_inject_irq)(vcpu, false);
 			WARN_ON(static_call(kvm_x86_interrupt_allowed)(vcpu, true) < 0);
 		}
 		if (kvm_cpu_has_injectable_intr(vcpu))