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