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 #include "xen.h" 18 19 /* 20 * check if there are pending timer events 21 * to be processed. 22 */ 23 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 24 { 25 int r = 0; 26 27 if (lapic_in_kernel(vcpu)) 28 r = apic_has_pending_timer(vcpu); 29 if (kvm_xen_timer_enabled(vcpu)) 30 r += kvm_xen_has_pending_timer(vcpu); 31 32 return r; 33 } 34 EXPORT_SYMBOL(kvm_cpu_has_pending_timer); 35 36 /* 37 * check if there is a pending userspace external interrupt 38 */ 39 static int pending_userspace_extint(struct kvm_vcpu *v) 40 { 41 return v->arch.pending_external_vector != -1; 42 } 43 44 /* 45 * check if there is pending interrupt from 46 * non-APIC source without intack. 47 */ 48 int kvm_cpu_has_extint(struct kvm_vcpu *v) 49 { 50 /* 51 * FIXME: interrupt.injected represents an interrupt whose 52 * side-effects have already been applied (e.g. bit from IRR 53 * already moved to ISR). Therefore, it is incorrect to rely 54 * on interrupt.injected to know if there is a pending 55 * interrupt in the user-mode LAPIC. 56 * This leads to nVMX/nSVM not be able to distinguish 57 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 58 * pending interrupt or should re-inject an injected 59 * interrupt. 60 */ 61 if (!lapic_in_kernel(v)) 62 return v->arch.interrupt.injected; 63 64 if (kvm_xen_has_interrupt(v)) 65 return 1; 66 67 if (!kvm_apic_accept_pic_intr(v)) 68 return 0; 69 70 if (irqchip_split(v->kvm)) 71 return pending_userspace_extint(v); 72 else 73 return v->kvm->arch.vpic->output; 74 } 75 76 /* 77 * check if there is injectable interrupt: 78 * when virtual interrupt delivery enabled, 79 * interrupt from apic will handled by hardware, 80 * we don't need to check it here. 81 */ 82 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) 83 { 84 if (kvm_cpu_has_extint(v)) 85 return 1; 86 87 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v)) 88 return 0; 89 90 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 91 } 92 EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr); 93 94 /* 95 * check if there is pending interrupt without 96 * intack. 97 */ 98 int kvm_cpu_has_interrupt(struct kvm_vcpu *v) 99 { 100 if (kvm_cpu_has_extint(v)) 101 return 1; 102 103 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 104 } 105 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); 106 107 /* 108 * Read pending interrupt(from non-APIC source) 109 * vector and intack. 110 */ 111 static int kvm_cpu_get_extint(struct kvm_vcpu *v) 112 { 113 if (!kvm_cpu_has_extint(v)) { 114 WARN_ON(!lapic_in_kernel(v)); 115 return -1; 116 } 117 118 if (!lapic_in_kernel(v)) 119 return v->arch.interrupt.nr; 120 121 if (kvm_xen_has_interrupt(v)) 122 return v->kvm->arch.xen.upcall_vector; 123 124 if (irqchip_split(v->kvm)) { 125 int vector = v->arch.pending_external_vector; 126 127 v->arch.pending_external_vector = -1; 128 return vector; 129 } else 130 return kvm_pic_read_irq(v->kvm); /* PIC */ 131 } 132 133 /* 134 * Read pending interrupt vector and intack. 135 */ 136 int kvm_cpu_get_interrupt(struct kvm_vcpu *v) 137 { 138 int vector = kvm_cpu_get_extint(v); 139 if (vector != -1) 140 return vector; /* PIC */ 141 142 return kvm_get_apic_interrupt(v); /* APIC */ 143 } 144 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); 145 146 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) 147 { 148 if (lapic_in_kernel(vcpu)) 149 kvm_inject_apic_timer_irqs(vcpu); 150 if (kvm_xen_timer_enabled(vcpu)) 151 kvm_xen_inject_timer_irqs(vcpu); 152 } 153 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs); 154 155 void __kvm_migrate_timers(struct kvm_vcpu *vcpu) 156 { 157 __kvm_migrate_apic_timer(vcpu); 158 __kvm_migrate_pit_timer(vcpu); 159 static_call_cond(kvm_x86_migrate_timers)(vcpu); 160 } 161 162 bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) 163 { 164 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; 165 166 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); 167 } 168