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-rw-r--r--arch/x86/kvm/irq.c167
1 files changed, 167 insertions, 0 deletions
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
new file mode 100644
index 000000000..f371f1292
--- /dev/null
+++ b/arch/x86/kvm/irq.c
@@ -0,0 +1,167 @@
+// 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"
+#include "xen.h"
+
+/*
+ * check if there are pending timer events
+ * to be processed.
+ */
+int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+ int r = 0;
+
+ if (lapic_in_kernel(vcpu))
+ r = apic_has_pending_timer(vcpu);
+ if (kvm_xen_timer_enabled(vcpu))
+ r += kvm_xen_has_pending_timer(vcpu);
+
+ return r;
+}
+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_xen_has_interrupt(v))
+ return 1;
+
+ 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 (kvm_xen_has_interrupt(v))
+ return v->kvm->arch.xen.upcall_vector;
+
+ 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);
+ if (kvm_xen_timer_enabled(vcpu))
+ kvm_xen_inject_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);
+ static_call_cond(kvm_x86_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);
+}