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 static int kvm_cpu_has_extint(struct kvm_vcpu *v) 44 { 45 u8 accept = kvm_apic_accept_pic_intr(v); 46 47 if (accept) { 48 if (irqchip_split(v->kvm)) 49 return pending_userspace_extint(v); 50 else 51 return v->kvm->arch.vpic->output; 52 } else 53 return 0; 54 } 55 56 /* 57 * check if there is injectable interrupt: 58 * when virtual interrupt delivery enabled, 59 * interrupt from apic will handled by hardware, 60 * we don't need to check it here. 61 */ 62 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) 63 { 64 /* 65 * FIXME: interrupt.injected represents an interrupt that it's 66 * side-effects have already been applied (e.g. bit from IRR 67 * already moved to ISR). Therefore, it is incorrect to rely 68 * on interrupt.injected to know if there is a pending 69 * interrupt in the user-mode LAPIC. 70 * This leads to nVMX/nSVM not be able to distinguish 71 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 72 * pending interrupt or should re-inject an injected 73 * interrupt. 74 */ 75 if (!lapic_in_kernel(v)) 76 return v->arch.interrupt.injected; 77 78 if (kvm_cpu_has_extint(v)) 79 return 1; 80 81 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v)) 82 return 0; 83 84 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 85 } 86 87 /* 88 * check if there is pending interrupt without 89 * intack. 90 */ 91 int kvm_cpu_has_interrupt(struct kvm_vcpu *v) 92 { 93 /* 94 * FIXME: interrupt.injected represents an interrupt that it's 95 * side-effects have already been applied (e.g. bit from IRR 96 * already moved to ISR). Therefore, it is incorrect to rely 97 * on interrupt.injected to know if there is a pending 98 * interrupt in the user-mode LAPIC. 99 * This leads to nVMX/nSVM not be able to distinguish 100 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 101 * pending interrupt or should re-inject an injected 102 * interrupt. 103 */ 104 if (!lapic_in_kernel(v)) 105 return v->arch.interrupt.injected; 106 107 if (kvm_cpu_has_extint(v)) 108 return 1; 109 110 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 111 } 112 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); 113 114 /* 115 * Read pending interrupt(from non-APIC source) 116 * vector and intack. 117 */ 118 static int kvm_cpu_get_extint(struct kvm_vcpu *v) 119 { 120 if (kvm_cpu_has_extint(v)) { 121 if (irqchip_split(v->kvm)) { 122 int vector = v->arch.pending_external_vector; 123 124 v->arch.pending_external_vector = -1; 125 return vector; 126 } else 127 return kvm_pic_read_irq(v->kvm); /* PIC */ 128 } else 129 return -1; 130 } 131 132 /* 133 * Read pending interrupt vector and intack. 134 */ 135 int kvm_cpu_get_interrupt(struct kvm_vcpu *v) 136 { 137 int vector; 138 139 if (!lapic_in_kernel(v)) 140 return v->arch.interrupt.nr; 141 142 vector = kvm_cpu_get_extint(v); 143 144 if (vector != -1) 145 return vector; /* PIC */ 146 147 return kvm_get_apic_interrupt(v); /* APIC */ 148 } 149 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); 150 151 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) 152 { 153 if (lapic_in_kernel(vcpu)) 154 kvm_inject_apic_timer_irqs(vcpu); 155 } 156 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs); 157 158 void __kvm_migrate_timers(struct kvm_vcpu *vcpu) 159 { 160 __kvm_migrate_apic_timer(vcpu); 161 __kvm_migrate_pit_timer(vcpu); 162 } 163 164 bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) 165 { 166 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; 167 168 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); 169 } 170