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 35 /* 36 * check if there is a pending userspace external interrupt 37 */ 38 static int pending_userspace_extint(struct kvm_vcpu *v) 39 { 40 return v->arch.pending_external_vector != -1; 41 } 42 43 /* 44 * check if there is pending interrupt from 45 * non-APIC source without intack. 46 */ 47 int kvm_cpu_has_extint(struct kvm_vcpu *v) 48 { 49 /* 50 * FIXME: interrupt.injected represents an interrupt whose 51 * side-effects have already been applied (e.g. bit from IRR 52 * already moved to ISR). Therefore, it is incorrect to rely 53 * on interrupt.injected to know if there is a pending 54 * interrupt in the user-mode LAPIC. 55 * This leads to nVMX/nSVM not be able to distinguish 56 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 57 * pending interrupt or should re-inject an injected 58 * interrupt. 59 */ 60 if (!lapic_in_kernel(v)) 61 return v->arch.interrupt.injected; 62 63 if (kvm_xen_has_interrupt(v)) 64 return 1; 65 66 if (!kvm_apic_accept_pic_intr(v)) 67 return 0; 68 69 if (irqchip_split(v->kvm)) 70 return pending_userspace_extint(v); 71 else 72 return v->kvm->arch.vpic->output; 73 } 74 75 /* 76 * check if there is injectable interrupt: 77 * when virtual interrupt delivery enabled, 78 * interrupt from apic will handled by hardware, 79 * we don't need to check it here. 80 */ 81 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) 82 { 83 if (kvm_cpu_has_extint(v)) 84 return 1; 85 86 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v)) 87 return 0; 88 89 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 90 } 91 EXPORT_SYMBOL_GPL(kvm_cpu_has_injectable_intr); 92 93 /* 94 * check if there is pending interrupt without 95 * intack. 96 */ 97 int kvm_cpu_has_interrupt(struct kvm_vcpu *v) 98 { 99 if (kvm_cpu_has_extint(v)) 100 return 1; 101 102 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 103 } 104 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); 105 106 /* 107 * Read pending interrupt(from non-APIC source) 108 * vector and intack. 109 */ 110 static int kvm_cpu_get_extint(struct kvm_vcpu *v) 111 { 112 if (!kvm_cpu_has_extint(v)) { 113 WARN_ON(!lapic_in_kernel(v)); 114 return -1; 115 } 116 117 if (!lapic_in_kernel(v)) 118 return v->arch.interrupt.nr; 119 120 if (kvm_xen_has_interrupt(v)) 121 return v->kvm->arch.xen.upcall_vector; 122 123 if (irqchip_split(v->kvm)) { 124 int vector = v->arch.pending_external_vector; 125 126 v->arch.pending_external_vector = -1; 127 return vector; 128 } else 129 return kvm_pic_read_irq(v->kvm); /* PIC */ 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 = kvm_cpu_get_extint(v); 138 if (vector != -1) 139 return vector; /* PIC */ 140 141 return kvm_get_apic_interrupt(v); /* APIC */ 142 } 143 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); 144 145 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) 146 { 147 if (lapic_in_kernel(vcpu)) 148 kvm_inject_apic_timer_irqs(vcpu); 149 if (kvm_xen_timer_enabled(vcpu)) 150 kvm_xen_inject_timer_irqs(vcpu); 151 } 152 153 void __kvm_migrate_timers(struct kvm_vcpu *vcpu) 154 { 155 __kvm_migrate_apic_timer(vcpu); 156 __kvm_migrate_pit_timer(vcpu); 157 static_call_cond(kvm_x86_migrate_timers)(vcpu); 158 } 159 160 bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) 161 { 162 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; 163 164 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); 165 } 166 167 bool kvm_arch_irqchip_in_kernel(struct kvm *kvm) 168 { 169 return irqchip_in_kernel(kvm); 170 } 171