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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/export.h> 13 #include <linux/kvm_host.h> 14 15 #include "irq.h" 16 #include "i8254.h" 17 #include "x86.h" 18 #include "xen.h" 19 20 /* 21 * check if there are pending timer events 22 * to be processed. 23 */ kvm_cpu_has_pending_timer(struct kvm_vcpu * vcpu)24int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 25 { 26 int r = 0; 27 28 if (lapic_in_kernel(vcpu)) 29 r = apic_has_pending_timer(vcpu); 30 if (kvm_xen_timer_enabled(vcpu)) 31 r += kvm_xen_has_pending_timer(vcpu); 32 33 return r; 34 } 35 36 /* 37 * check if there is a pending userspace external interrupt 38 */ pending_userspace_extint(struct kvm_vcpu * v)39static 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 */ kvm_cpu_has_extint(struct kvm_vcpu * v)48int 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 */ kvm_cpu_has_injectable_intr(struct kvm_vcpu * v)82int 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 */ kvm_cpu_has_interrupt(struct kvm_vcpu * v)98int kvm_cpu_has_interrupt(struct kvm_vcpu *v) 99 { 100 if (kvm_cpu_has_extint(v)) 101 return 1; 102 103 if (lapic_in_kernel(v) && v->arch.apic->guest_apic_protected) 104 return kvm_x86_call(protected_apic_has_interrupt)(v); 105 106 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 107 } 108 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); 109 110 /* 111 * Read pending interrupt(from non-APIC source) 112 * vector and intack. 113 */ kvm_cpu_get_extint(struct kvm_vcpu * v)114int kvm_cpu_get_extint(struct kvm_vcpu *v) 115 { 116 if (!kvm_cpu_has_extint(v)) { 117 WARN_ON(!lapic_in_kernel(v)); 118 return -1; 119 } 120 121 if (!lapic_in_kernel(v)) 122 return v->arch.interrupt.nr; 123 124 #ifdef CONFIG_KVM_XEN 125 if (kvm_xen_has_interrupt(v)) 126 return v->kvm->arch.xen.upcall_vector; 127 #endif 128 129 if (irqchip_split(v->kvm)) { 130 int vector = v->arch.pending_external_vector; 131 132 v->arch.pending_external_vector = -1; 133 return vector; 134 } else 135 return kvm_pic_read_irq(v->kvm); /* PIC */ 136 } 137 EXPORT_SYMBOL_GPL(kvm_cpu_get_extint); 138 139 /* 140 * Read pending interrupt vector and intack. 141 */ kvm_cpu_get_interrupt(struct kvm_vcpu * v)142int kvm_cpu_get_interrupt(struct kvm_vcpu *v) 143 { 144 int vector = kvm_cpu_get_extint(v); 145 if (vector != -1) 146 return vector; /* PIC */ 147 148 vector = kvm_apic_has_interrupt(v); /* APIC */ 149 if (vector != -1) 150 kvm_apic_ack_interrupt(v, vector); 151 152 return vector; 153 } 154 kvm_inject_pending_timer_irqs(struct kvm_vcpu * vcpu)155void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) 156 { 157 if (lapic_in_kernel(vcpu)) 158 kvm_inject_apic_timer_irqs(vcpu); 159 if (kvm_xen_timer_enabled(vcpu)) 160 kvm_xen_inject_timer_irqs(vcpu); 161 } 162 __kvm_migrate_timers(struct kvm_vcpu * vcpu)163void __kvm_migrate_timers(struct kvm_vcpu *vcpu) 164 { 165 __kvm_migrate_apic_timer(vcpu); 166 __kvm_migrate_pit_timer(vcpu); 167 kvm_x86_call(migrate_timers)(vcpu); 168 } 169 kvm_arch_irqfd_allowed(struct kvm * kvm,struct kvm_irqfd * args)170bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) 171 { 172 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; 173 174 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); 175 } 176 kvm_arch_irqchip_in_kernel(struct kvm * kvm)177bool kvm_arch_irqchip_in_kernel(struct kvm *kvm) 178 { 179 return irqchip_in_kernel(kvm); 180 } 181