4 files changed, 68 insertions, 15 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 7a5f9debbcd8..76a5b30979b3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -576,6 +576,7 @@ struct kvm_vcpu_arch {
 	} pv;
 
 	int pending_ioapic_eoi;
+	int pending_external_vector;
 };
 
 struct kvm_lpage_info {
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index b653ae202c8e..097060e33bd6 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -38,14 +38,27 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
 
 /*
+ * check if there is a pending userspace external interrupt
+ */
+static int pending_userspace_extint(struct kvm_vcpu *v)
+{
+	return v->arch.pending_external_vector != -1;
+}
+
+/*
  * check if there is pending interrupt from
  * non-APIC source without intack.
  */
 static int kvm_cpu_has_extint(struct kvm_vcpu *v)
 {
-	if (kvm_apic_accept_pic_intr(v))
-		return pic_irqchip(v->kvm)->output;	/* PIC */
-	else
+	u8 accept = kvm_apic_accept_pic_intr(v);
+
+	if (accept) {
+		if (irqchip_split(v->kvm))
+			return pending_userspace_extint(v);
+		else
+			return pic_irqchip(v->kvm)->output;
+	} else
 		return 0;
 }
 
@@ -91,9 +104,16 @@ EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
  */
 static int kvm_cpu_get_extint(struct kvm_vcpu *v)
 {
-	if (kvm_cpu_has_extint(v))
-		return kvm_pic_read_irq(v->kvm); /* PIC */
-	return -1;
+	if (kvm_cpu_has_extint(v)) {
+		if (irqchip_split(v->kvm)) {
+			int vector = v->arch.pending_external_vector;
+
+			v->arch.pending_external_vector = -1;
+			return vector;
+		} else
+			return kvm_pic_read_irq(v->kvm); /* PIC */
+	} else
+		return -1;
 }
 
 /*
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 2f9703dcd913..ae5c78f2337d 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -83,6 +83,14 @@ static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
 	return kvm->arch.vpic;
 }
 
+static inline int pic_in_kernel(struct kvm *kvm)
+{
+	int ret;
+
+	ret = (pic_irqchip(kvm) != NULL);
+	return ret;
+}
+
 static inline int irqchip_split(struct kvm *kvm)
 {
 	return kvm->arch.irqchip_split;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4aeed2086c5e..8b97c54edebc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2662,12 +2662,24 @@ static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
 {
 	if (irq->irq >= KVM_NR_INTERRUPTS)
 		return -EINVAL;
-	if (irqchip_in_kernel(vcpu->kvm))
+
+	if (!irqchip_in_kernel(vcpu->kvm)) {
+		kvm_queue_interrupt(vcpu, irq->irq, false);
+		kvm_make_request(KVM_REQ_EVENT, vcpu);
+		return 0;
+	}
+
+	/*
+	 * With in-kernel LAPIC, we only use this to inject EXTINT, so
+	 * fail for in-kernel 8259.
+	 */
+	if (pic_in_kernel(vcpu->kvm))
 		return -ENXIO;
 
-	kvm_queue_interrupt(vcpu, irq->irq, false);
-	kvm_make_request(KVM_REQ_EVENT, vcpu);
+	if (vcpu->arch.pending_external_vector != -1)
+		return -EEXIST;
 
+	vcpu->arch.pending_external_vector = irq->irq;
 	return 0;
 }
 
@@ -5796,9 +5808,15 @@ static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
  */
 static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
 {
-	return (!irqchip_in_kernel(vcpu->kvm) && !kvm_cpu_has_interrupt(vcpu) &&
-		vcpu->run->request_interrupt_window &&
-		kvm_arch_interrupt_allowed(vcpu));
+	if (!vcpu->run->request_interrupt_window || pic_in_kernel(vcpu->kvm))
+		return false;
+
+	if (kvm_cpu_has_interrupt(vcpu))
+		return false;
+
+	return (irqchip_split(vcpu->kvm)
+		? kvm_apic_accept_pic_intr(vcpu)
+		: kvm_arch_interrupt_allowed(vcpu));
 }
 
 static void post_kvm_run_save(struct kvm_vcpu *vcpu)
@@ -5809,13 +5827,17 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu)
 	kvm_run->flags = is_smm(vcpu) ? KVM_RUN_X86_SMM : 0;
 	kvm_run->cr8 = kvm_get_cr8(vcpu);
 	kvm_run->apic_base = kvm_get_apic_base(vcpu);
-	if (irqchip_in_kernel(vcpu->kvm))
-		kvm_run->ready_for_interrupt_injection = 1;
-	else
+	if (!irqchip_in_kernel(vcpu->kvm))
 		kvm_run->ready_for_interrupt_injection =
 			kvm_arch_interrupt_allowed(vcpu) &&
 			!kvm_cpu_has_interrupt(vcpu) &&
 			!kvm_event_needs_reinjection(vcpu);
+	else if (!pic_in_kernel(vcpu->kvm))
+		kvm_run->ready_for_interrupt_injection =
+			kvm_apic_accept_pic_intr(vcpu) &&
+			!kvm_cpu_has_interrupt(vcpu);
+	else
+		kvm_run->ready_for_interrupt_injection = 1;
 }
 
 static void update_cr8_intercept(struct kvm_vcpu *vcpu)
@@ -7403,6 +7425,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 	kvm_async_pf_hash_reset(vcpu);
 	kvm_pmu_init(vcpu);
 
+	vcpu->arch.pending_external_vector = -1;
+
 	return 0;
 
 fail_free_mce_banks: