[PATCH v2 09/11] KVM: x86: Differentiate Soft vs. Hard IRQs vs. reinjected in tracepoint

From: Sean Christopherson <seanjc@google.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Maxim Levitsky <mlevitsk@redhat.com>,
	"Maciej S . Szmigiero" <maciej.szmigiero@oracle.com>
Subject: [PATCH v2 09/11] KVM: x86: Differentiate Soft vs. Hard IRQs vs. reinjected in tracepoint
Date: Sat, 23 Apr 2022 02:14:09 +0000	[thread overview]
Message-ID: <20220423021411.784383-10-seanjc@google.com> (raw)
In-Reply-To: <20220423021411.784383-1-seanjc@google.com>

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>
---
 arch/x86/include/asm/kvm_host.h |  2 +-
 arch/x86/kvm/svm/svm.c          |  5 +++--
 arch/x86/kvm/trace.h            | 16 +++++++++++-----
 arch/x86/kvm/vmx/vmx.c          |  4 ++--
 arch/x86/kvm/x86.c              |  4 ++--
 5 files changed, 19 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f164c6c1514a..ae088c6fb287 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1400,7 +1400,7 @@ struct kvm_x86_ops {
 	u32 (*get_interrupt_shadow)(struct kvm_vcpu *vcpu);
 	void (*patch_hypercall)(struct kvm_vcpu *vcpu,
 				unsigned char *hypercall_addr);
-	void (*inject_irq)(struct kvm_vcpu *vcpu);
+	void (*inject_irq)(struct kvm_vcpu *vcpu, bool reinjected);
 	void (*inject_nmi)(struct kvm_vcpu *vcpu);
 	void (*queue_exception)(struct kvm_vcpu *vcpu);
 	void (*cancel_injection)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index b8fb07eeeca5..4a912623b961 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -3427,7 +3427,7 @@ 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;
@@ -3442,7 +3442,8 @@ 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..e1b089285c55 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(	unsigned int,	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 cf8581978bce..a0083464682d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4566,13 +4566,13 @@ 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 c3ee8dc00d3a..0a154b54b8aa 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9433,7 +9433,7 @@ 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;
 		}
 	}
@@ -9524,7 +9524,7 @@ 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))
-- 
2.36.0.rc2.479.g8af0fa9b8e-goog

