arch/x86/kvm/irq.c

   1 /*
   2  * irq.c: API for in kernel interrupt controller
   3  * Copyright (c) 2007, Intel Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA 02111-1307 USA.
  17  * Authors:
  18  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
  19  *
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/kvm_host.h>
  24
  25 #include "irq.h"
  26 #include "i8254.h"
  27
  28 /*
  29  * check if there are pending timer events
  30  * to be processed.
  31  */
  32 int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
  33 {
  34         int ret;
  35
  36         ret = pit_has_pending_timer(vcpu);
  37         ret |= apic_has_pending_timer(vcpu);
  38
  39         return ret;
  40 }
  41 EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
  42
  43 /*
  44  * check if there is pending interrupt without
  45  * intack.
  46  */
  47 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
  48 {
  49         struct kvm_pic *s;
  50
  51         if (kvm_apic_has_interrupt(v) == -1) {  /* LAPIC */
  52                 if (kvm_apic_accept_pic_intr(v)) {
  53                         s = pic_irqchip(v->kvm);        /* PIC */
  54                         return s->output;
  55                 } else
  56                         return 0;
  57         }
  58         return 1;
  59 }
  60 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
  61
  62 /*
  63  * Read pending interrupt vector and intack.
  64  */
  65 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
  66 {
  67         struct kvm_pic *s;
  68         int vector;
  69
  70         vector = kvm_get_apic_interrupt(v);     /* APIC */
  71         if (vector == -1) {
  72                 if (kvm_apic_accept_pic_intr(v)) {
  73                         s = pic_irqchip(v->kvm);
  74                         s->output = 0;          /* PIC */
  75                         vector = kvm_pic_read_irq(v->kvm);
  76                 }
  77         }
  78         return vector;
  79 }
  80 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
  81
  82 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
  83 {
  84         kvm_inject_apic_timer_irqs(vcpu);
  85         kvm_inject_pit_timer_irqs(vcpu);
  86         /* TODO: PIT, RTC etc. */
  87 }
  88 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
  89
  90 void kvm_timer_intr_post(struct kvm_vcpu *vcpu, int vec)
  91 {
  92         kvm_apic_timer_intr_post(vcpu, vec);
  93         /* TODO: PIT, RTC etc. */
  94 }
  95 EXPORT_SYMBOL_GPL(kvm_timer_intr_post);
  96
  97 void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
  98 {
  99         __kvm_migrate_apic_timer(vcpu);
 100         __kvm_migrate_pit_timer(vcpu);
 101 }
 102
 103 /* This should be called with the kvm->lock mutex held */
 104 void kvm_set_irq(struct kvm *kvm, int irq, int level)
 105 {
 106         /* Not possible to detect if the guest uses the PIC or the
 107          * IOAPIC.  So set the bit in both. The guest will ignore
 108          * writes to the unused one.
 109          */
 110         kvm_ioapic_set_irq(kvm->arch.vioapic, irq, level);
 111         kvm_pic_set_irq(pic_irqchip(kvm), irq, level);
 112 }
 113
 114 void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi)
 115 {
 116         struct kvm_irq_ack_notifier *kian;
 117         struct hlist_node *n;
 118
 119         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
 120                 if (kian->gsi == gsi)
 121                         kian->irq_acked(kian);
 122 }
 123
 124 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 125                                    struct kvm_irq_ack_notifier *kian)
 126 {
 127         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
 128 }
 129
 130 void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
 131                                      struct kvm_irq_ack_notifier *kian)
 132 {
 133         hlist_del(&kian->link);
 134 }