1 /* 2 * irq.c: API for in kernel interrupt controller 3 * Copyright (c) 2007, Intel Corporation. 4 * Copyright 2009 Red Hat, Inc. and/or its affiliates. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple 17 * Place - Suite 330, Boston, MA 02111-1307 USA. 18 * Authors: 19 * Yaozu (Eddie) Dong <Eddie.dong@intel.com> 20 * 21 */ 22 23 #include <linux/export.h> 24 #include <linux/kvm_host.h> 25 26 #include "irq.h" 27 #include "i8254.h" 28 #include "x86.h" 29 30 /* 31 * check if there are pending timer events 32 * to be processed. 33 */ 34 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) 35 { 36 if (lapic_in_kernel(vcpu)) 37 return apic_has_pending_timer(vcpu); 38 39 return 0; 40 } 41 EXPORT_SYMBOL(kvm_cpu_has_pending_timer); 42 43 /* 44 * check if there is a pending userspace external interrupt 45 */ 46 static int pending_userspace_extint(struct kvm_vcpu *v) 47 { 48 return v->arch.pending_external_vector != -1; 49 } 50 51 /* 52 * check if there is pending interrupt from 53 * non-APIC source without intack. 54 */ 55 static int kvm_cpu_has_extint(struct kvm_vcpu *v) 56 { 57 u8 accept = kvm_apic_accept_pic_intr(v); 58 59 if (accept) { 60 if (irqchip_split(v->kvm)) 61 return pending_userspace_extint(v); 62 else 63 return v->kvm->arch.vpic->output; 64 } else 65 return 0; 66 } 67 68 /* 69 * check if there is injectable interrupt: 70 * when virtual interrupt delivery enabled, 71 * interrupt from apic will handled by hardware, 72 * we don't need to check it here. 73 */ 74 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v) 75 { 76 /* 77 * FIXME: interrupt.injected represents an interrupt that it's 78 * side-effects have already been applied (e.g. bit from IRR 79 * already moved to ISR). Therefore, it is incorrect to rely 80 * on interrupt.injected to know if there is a pending 81 * interrupt in the user-mode LAPIC. 82 * This leads to nVMX/nSVM not be able to distinguish 83 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 84 * pending interrupt or should re-inject an injected 85 * interrupt. 86 */ 87 if (!lapic_in_kernel(v)) 88 return v->arch.interrupt.injected; 89 90 if (kvm_cpu_has_extint(v)) 91 return 1; 92 93 if (!is_guest_mode(v) && kvm_vcpu_apicv_active(v)) 94 return 0; 95 96 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 97 } 98 99 /* 100 * check if there is pending interrupt without 101 * intack. 102 */ 103 int kvm_cpu_has_interrupt(struct kvm_vcpu *v) 104 { 105 /* 106 * FIXME: interrupt.injected represents an interrupt that it's 107 * side-effects have already been applied (e.g. bit from IRR 108 * already moved to ISR). Therefore, it is incorrect to rely 109 * on interrupt.injected to know if there is a pending 110 * interrupt in the user-mode LAPIC. 111 * This leads to nVMX/nSVM not be able to distinguish 112 * if it should exit from L2 to L1 on EXTERNAL_INTERRUPT on 113 * pending interrupt or should re-inject an injected 114 * interrupt. 115 */ 116 if (!lapic_in_kernel(v)) 117 return v->arch.interrupt.injected; 118 119 if (kvm_cpu_has_extint(v)) 120 return 1; 121 122 return kvm_apic_has_interrupt(v) != -1; /* LAPIC */ 123 } 124 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt); 125 126 /* 127 * Read pending interrupt(from non-APIC source) 128 * vector and intack. 129 */ 130 static int kvm_cpu_get_extint(struct kvm_vcpu *v) 131 { 132 if (kvm_cpu_has_extint(v)) { 133 if (irqchip_split(v->kvm)) { 134 int vector = v->arch.pending_external_vector; 135 136 v->arch.pending_external_vector = -1; 137 return vector; 138 } else 139 return kvm_pic_read_irq(v->kvm); /* PIC */ 140 } else 141 return -1; 142 } 143 144 /* 145 * Read pending interrupt vector and intack. 146 */ 147 int kvm_cpu_get_interrupt(struct kvm_vcpu *v) 148 { 149 int vector; 150 151 if (!lapic_in_kernel(v)) 152 return v->arch.interrupt.nr; 153 154 vector = kvm_cpu_get_extint(v); 155 156 if (vector != -1) 157 return vector; /* PIC */ 158 159 return kvm_get_apic_interrupt(v); /* APIC */ 160 } 161 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt); 162 163 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu) 164 { 165 if (lapic_in_kernel(vcpu)) 166 kvm_inject_apic_timer_irqs(vcpu); 167 } 168 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs); 169 170 void __kvm_migrate_timers(struct kvm_vcpu *vcpu) 171 { 172 __kvm_migrate_apic_timer(vcpu); 173 __kvm_migrate_pit_timer(vcpu); 174 } 175 176 bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args) 177 { 178 bool resample = args->flags & KVM_IRQFD_FLAG_RESAMPLE; 179 180 return resample ? irqchip_kernel(kvm) : irqchip_in_kernel(kvm); 181 } 182