1 files changed, 155 insertions, 0 deletions
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
new file mode 100644
index 000000000..814698e5b
--- /dev/null
+++ b/arch/x86/kvm/irq.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * irq.c: API for in kernel interrupt controller
+ * Copyright (c) 2007, Intel Corporation.
+ * Copyright 2009 Red Hat, Inc. and/or its affiliates.
+ *
+ * Authors:
+ *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
+ */
+
+#include <linux/export.h>
+#include <linux/kvm_host.h>
+
+#include "irq.h"
+#include "i8254.h"
+#include "x86.h"
+
+/*
+ * check if there are pending timer events
+ * to be processed.
+ */
+int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+	if (lapic_in_kernel(vcpu))
+		return apic_has_pending_timer(vcpu);
+
+	return 0;
+}
+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.
+ */
+int kvm_cpu_has_extint(struct kvm_vcpu *v)
+{
+	/*
+	 * FIXME: interrupt.injected represents an interrupt whose
+	 * side-effects have already been applied (e.g. bit from IRR
+	 * already moved to ISR). Therefore, it is incorrect to rely
+	 * on interrupt.injected to know if there is a pending
+	 * interrupt in the user-mode LAPIC.
+	 * This leads to nVMX/nSVM not be able to distinguish
+	 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on
+	 * pending interrupt or should re-inject an injected
+	 * interrupt.
+	 */
+	if (!lapic_in_kernel(v))
+		return v->arch.interrupt.injected;
+
+	if (!kvm_apic_accept_pic_intr(v))
+		return 0;
+
+	if (irqchip_split(v->kvm))
+		return pending_userspace_extint(v);
+	else
+		return v->kvm->arch.vpic->output;
+}
+
+/*
+ * check if there is injectable interrupt:
+ * when virtual interrupt delivery enabled,
+ * interrupt from apic will handled by hardware,
+ * we don't need to check it here.
+ */
+int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
+{
+	if (kvm_cpu_has_extint(v))
+		return 1;
+
+	if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v))
+		return 0;
+
+	return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
+}
+EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr);
+
+/*
+ * check if there is pending interrupt without
+ * intack.
+ */
+int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
+{
+	if (kvm_cpu_has_extint(v))
+		return 1;
+
+	return kvm_apic_has_interrupt(v) != -1;	/* LAPIC */
+}
+EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
+
+/*
+ * Read pending interrupt(from non-APIC source)
+ * vector and intack.
+ */
+static int kvm_cpu_get_extint(struct kvm_vcpu *v)
+{
+	if (!kvm_cpu_has_extint(v)) {
+		WARN_ON(!lapic_in_kernel(v));
+		return -1;
+	}
+
+	if (!lapic_in_kernel(v))
+		return v->arch.interrupt.nr;
+
+	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 */
+}
+
+/*
+ * Read pending interrupt vector and intack.
+ */
+int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
+{
+	int vector = kvm_cpu_get_extint(v);
+	if (vector != -1)
+		return vector;			/* PIC */
+
+	return kvm_get_apic_interrupt(v);	/* APIC */
+}
+EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
+
+void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
+{
+	if (lapic_in_kernel(vcpu))
+		kvm_inject_apic_timer_irqs(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
+
+void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
+{
+	__kvm_migrate_apic_timer(vcpu);
+	__kvm_migrate_pit_timer(vcpu);
+	if (kvm_x86_ops.migrate_timers)
+		kvm_x86_ops.migrate_timers(vcpu);
+}
+
+bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args)
+{
+	bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE;
+
+	return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm);
+}