kernel/arch/x86/kvm/irq.c

   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/module.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         return apic_has_pending_timer(vcpu);
  37 }
  38 EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
  39
  40 /*
  41  * check if there is a pending userspace external interrupt
  42  */
  43 static int pending_userspace_extint(struct kvm_vcpu *v)
  44 {
  45         return v->arch.pending_external_vector != -1;
  46 }
  47
  48 /*
  49  * check if there is pending interrupt from
  50  * non-APIC source without intack.
  51  */
  52 static int kvm_cpu_has_extint(struct kvm_vcpu *v)
  53 {
  54         u8 accept = kvm_apic_accept_pic_intr(v);
  55
  56         if (accept) {
  57                 if (irqchip_split(v->kvm))
  58                         return pending_userspace_extint(v);
  59                 else
  60                         return pic_irqchip(v->kvm)->output;
  61         } else
  62                 return 0;
  63 }
  64
  65 /*
  66  * check if there is injectable interrupt:
  67  * when virtual interrupt delivery enabled,
  68  * interrupt from apic will handled by hardware,
  69  * we don't need to check it here.
  70  */
  71 int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
  72 {
  73         if (!lapic_in_kernel(v))
  74                 return v->arch.interrupt.pending;
  75
  76         if (kvm_cpu_has_extint(v))
  77                 return 1;
  78
  79         if (kvm_vcpu_apic_vid_enabled(v))
  80                 return 0;
  81
  82         return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
  83 }
  84
  85 /*
  86  * check if there is pending interrupt without
  87  * intack.
  88  */
  89 int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
  90 {
  91         if (!lapic_in_kernel(v))
  92                 return v->arch.interrupt.pending;
  93
  94         if (kvm_cpu_has_extint(v))
  95                 return 1;
  96
  97         return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
  98 }
  99 EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
 100
 101 /*
 102  * Read pending interrupt(from non-APIC source)
 103  * vector and intack.
 104  */
 105 static int kvm_cpu_get_extint(struct kvm_vcpu *v)
 106 {
 107         if (kvm_cpu_has_extint(v)) {
 108                 if (irqchip_split(v->kvm)) {
 109                         int vector = v->arch.pending_external_vector;
 110
 111                         v->arch.pending_external_vector = -1;
 112                         return vector;
 113                 } else
 114                         return kvm_pic_read_irq(v->kvm); /* PIC */
 115         } else
 116                 return -1;
 117 }
 118
 119 /*
 120  * Read pending interrupt vector and intack.
 121  */
 122 int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
 123 {
 124         int vector;
 125
 126         if (!lapic_in_kernel(v))
 127                 return v->arch.interrupt.nr;
 128
 129         vector = kvm_cpu_get_extint(v);
 130
 131         if (vector != -1)
 132                 return vector;                  /* PIC */
 133
 134         return kvm_get_apic_interrupt(v);       /* APIC */
 135 }
 136 EXPORT_SYMBOL_GPL(kvm_cpu_get_interrupt);
 137
 138 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu)
 139 {
 140         kvm_inject_apic_timer_irqs(vcpu);
 141         /* TODO: PIT, RTC etc. */
 142 }
 143 EXPORT_SYMBOL_GPL(kvm_inject_pending_timer_irqs);
 144
 145 void __kvm_migrate_timers(struct kvm_vcpu *vcpu)
 146 {
 147         __kvm_migrate_apic_timer(vcpu);
 148         __kvm_migrate_pit_timer(vcpu);
 149 }