1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * irq.c: API for in kernel interrupt controller 4 * Copyright (c) 2007, Intel Corporation. 5 * Copyright 2009 Red Hat, Inc. and/or its affiliates. 6 * 7 * Authors: 8 * Yaozu (Eddie) Dong <Eddie.dong@intel.com> 9 */ 10 11 #include <linux/export.h> 12 #include <linux/kvm_host.h> 13 14 #include "irq.h" 15 #include "i8254.h" 16 #include "x86.h" 17 18 /* 19 * check if there are pending timer events 20 * to be processed. 21 */ 22 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 23 { 24 if (lapic_in_kernel(vcpu)) 25 return apic_has_pending_timer(vcpu); 26 27 return 0; 28 } 29 EXPORT_SYMBOL(kvm_cpu_has_pending_timer); 30 31 /* 32 * check if there is a pending userspace external interrupt 33 */ 34 static int pending_userspace_extint(struct kvm_vcpu *v) 35 { 36 return v->arch.pending_external_vector != -1; 37 } 38 39 /* 40 * check if there is pending interrupt from 41 * non-APIC source without intack. 42 */ 43 int kvm_cpu_has_extint(struct kvm_vcpu *v) 44 { 45 /* 46 * FIXME: interrupt.injected represents an interrupt whose 47 * side-effects have already been applied (e.g. bit from IRR 48 * already moved to ISR). Therefore, it is incorrect to rely 49 * on interrupt.injected to know if there is a pending 50 * interrupt in the user-mode LAPIC. 51 * This leads to nVMX/nSVM not be able to distinguish 52 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 53 * pending interrupt or should re-inject an injected 54 * interrupt. 55 */ 56 if (!lapic_in_kernel(v)) 57 return v->arch.interrupt.injected; 58 59 if (!kvm_apic_accept_pic_intr(v)) 60 return 0; 61 62 if (irqchip_split(v->kvm)) 63 return pending_userspace_extint(v); 64 else 65 return v->kvm->arch.vpic->output; 66 } 67 68 /* 69 * check if there is injectable interrupt: 70 * when virtual interrupt delivery enabled, 71 * interrupt from apic will handled by hardware, 72 * we don't need to check it here. 73 */ 74 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) 75 { 76 if (kvm_cpu_has_extint(v)) 77 return 1; 78 79 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v)) 80 return 0; 81 82 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 83 } 84 EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr); 85 86 /* 87 * check if there is pending interrupt without 88 * intack. 89 */ 90 int kvm_cpu_has_interrupt(struct kvm_vcpu *v) 91 { 92 if (kvm_cpu_has_extint(v)) 93 return 1; 94 95 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 96 } 97 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); 98 99 /* 100 * Read pending interrupt(from non-APIC source) 101 * vector and intack. 102 */ 103 static int kvm_cpu_get_extint(struct kvm_vcpu *v) 104 { 105 if (!kvm_cpu_has_extint(v)) { 106 WARN_ON(!lapic_in_kernel(v)); 107 return -1; 108 } 109 110 if (!lapic_in_kernel(v)) 111 return v->arch.interrupt.nr; 112 113 if (irqchip_split(v->kvm)) { 114 int vector = v->arch.pending_external_vector; 115 116 v->arch.pending_external_vector = -1; 117 return vector; 118 } else 119 return kvm_pic_read_irq(v->kvm); /* PIC */ 120 } 121 122 /* 123 * Read pending interrupt vector and intack. 124 */ 125 int kvm_cpu_get_interrupt(struct kvm_vcpu *v) 126 { 127 int vector = kvm_cpu_get_extint(v); 128 if (vector != -1) 129 return vector; /* PIC */ 130 131 return kvm_get_apic_interrupt(v); /* APIC */ 132 } 133 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); 134 135 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) 136 { 137 if (lapic_in_kernel(vcpu)) 138 kvm_inject_apic_timer_irqs(vcpu); 139 } 140 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs); 141 142 void __kvm_migrate_timers(struct kvm_vcpu *vcpu) 143 { 144 __kvm_migrate_apic_timer(vcpu); 145 __kvm_migrate_pit_timer(vcpu); 146 if (kvm_x86_ops.migrate_timers) 147 kvm_x86_ops.migrate_timers(vcpu); 148 } 149 150 bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) 151 { 152 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; 153 154 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); 155 } 156