virt/kvm/irq_comm.c

   1 /*
   2  * irq_comm.c: Common 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/kvm_host.h>
  23 #include "irq.h"
  24
  25 #include "ioapic.h"
  26
  27 static void kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  28                             struct kvm *kvm, int level)
  29 {
  30 #ifdef CONFIG_X86
  31         kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
  32 #endif
  33 }
  34
  35 static void kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  36                                struct kvm *kvm, int level)
  37 {
  38         kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
  39 }
  40
  41 /* This should be called with the kvm->lock mutex held */
  42 void kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
  43 {
  44         struct kvm_kernel_irq_routing_entry *e;
  45         unsigned long *irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
  46
  47         /* Logical OR for level trig interrupt */
  48         if (level)
  49                 set_bit(irq_source_id, irq_state);
  50         else
  51                 clear_bit(irq_source_id, irq_state);
  52
  53         /* Not possible to detect if the guest uses the PIC or the
  54          * IOAPIC.  So set the bit in both. The guest will ignore
  55          * writes to the unused one.
  56          */
  57         list_for_each_entry(e, &kvm->irq_routing, link)
  58                 if (e->gsi == irq)
  59                         e->set(e, kvm, !!(*irq_state));
  60 }
  61
  62 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
  63 {
  64         struct kvm_kernel_irq_routing_entry *e;
  65         struct kvm_irq_ack_notifier *kian;
  66         struct hlist_node *n;
  67         unsigned gsi = pin;
  68
  69         list_for_each_entry(e, &kvm->irq_routing, link)
  70                 if (e->irqchip.irqchip == irqchip &&
  71                     e->irqchip.pin == pin) {
  72                         gsi = e->gsi;
  73                         break;
  74                 }
  75
  76         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
  77                 if (kian->gsi == gsi)
  78                         kian->irq_acked(kian);
  79 }
  80
  81 void kvm_register_irq_ack_notifier(struct kvm *kvm,
  82                                    struct kvm_irq_ack_notifier *kian)
  83 {
  84         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
  85 }
  86
  87 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
  88 {
  89         hlist_del_init(&kian->link);
  90 }
  91
  92 /* The caller must hold kvm->lock mutex */
  93 int kvm_request_irq_source_id(struct kvm *kvm)
  94 {
  95         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
  96         int irq_source_id = find_first_zero_bit(bitmap,
  97                                 sizeof(kvm->arch.irq_sources_bitmap));
  98
  99         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 100                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 101                 return -EFAULT;
 102         }
 103
 104         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 105         set_bit(irq_source_id, bitmap);
 106
 107         return irq_source_id;
 108 }
 109
 110 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 111 {
 112         int i;
 113
 114         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 115
 116         if (irq_source_id < 0 ||
 117             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 118                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 119                 return;
 120         }
 121         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 122                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 123         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 124 }
 125
 126 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 127                                     struct kvm_irq_mask_notifier *kimn)
 128 {
 129         kimn->irq = irq;
 130         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 131 }
 132
 133 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 134                                       struct kvm_irq_mask_notifier *kimn)
 135 {
 136         hlist_del(&kimn->link);
 137 }
 138
 139 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 140 {
 141         struct kvm_irq_mask_notifier *kimn;
 142         struct hlist_node *n;
 143
 144         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 145                 if (kimn->irq == irq)
 146                         kimn->func(kimn, mask);
 147 }
 148
 149 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 150 {
 151         struct kvm_kernel_irq_routing_entry *e, *n;
 152
 153         list_for_each_entry_safe(e, n, irq_routing, link)
 154                 kfree(e);
 155 }
 156
 157 void kvm_free_irq_routing(struct kvm *kvm)
 158 {
 159         __kvm_free_irq_routing(&kvm->irq_routing);
 160 }
 161
 162 int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 163                         const struct kvm_irq_routing_entry *ue)
 164 {
 165         int r = -EINVAL;
 166         int delta;
 167
 168         e->gsi = ue->gsi;
 169         switch (ue->type) {
 170         case KVM_IRQ_ROUTING_IRQCHIP:
 171                 delta = 0;
 172                 switch (ue->u.irqchip.irqchip) {
 173                 case KVM_IRQCHIP_PIC_MASTER:
 174                         e->set = kvm_set_pic_irq;
 175                         break;
 176                 case KVM_IRQCHIP_PIC_SLAVE:
 177                                 e->set = kvm_set_pic_irq;
 178                         delta = 8;
 179                         break;
 180                 case KVM_IRQCHIP_IOAPIC:
 181                                 e->set = kvm_set_ioapic_irq;
 182                         break;
 183                 default:
 184                         goto out;
 185                 }
 186                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 187                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 188                 break;
 189         default:
 190                 goto out;
 191         }
 192         r = 0;
 193 out:
 194         return r;
 195 }
 196
 197
 198 int kvm_set_irq_routing(struct kvm *kvm,
 199                         const struct kvm_irq_routing_entry *ue,
 200                         unsigned nr,
 201                         unsigned flags)
 202 {
 203         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 204         struct list_head tmp = LIST_HEAD_INIT(tmp);
 205         struct kvm_kernel_irq_routing_entry *e = NULL;
 206         unsigned i;
 207         int r;
 208
 209         for (i = 0; i < nr; ++i) {
 210                 r = -EINVAL;
 211                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 212                         goto out;
 213                 if (ue->flags)
 214                         goto out;
 215                 r = -ENOMEM;
 216                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 217                 if (!e)
 218                         goto out;
 219                 r = setup_routing_entry(e, ue);
 220                 if (r)
 221                         goto out;
 222                 ++ue;
 223                 list_add(&e->link, &irq_list);
 224                 e = NULL;
 225         }
 226
 227         mutex_lock(&kvm->lock);
 228         list_splice(&kvm->irq_routing, &tmp);
 229         INIT_LIST_HEAD(&kvm->irq_routing);
 230         list_splice(&irq_list, &kvm->irq_routing);
 231         INIT_LIST_HEAD(&irq_list);
 232         list_splice(&tmp, &irq_list);
 233         mutex_unlock(&kvm->lock);
 234
 235         r = 0;
 236
 237 out:
 238         kfree(e);
 239         __kvm_free_irq_routing(&irq_list);
 240         return r;
 241 }
 242
 243 #define IOAPIC_ROUTING_ENTRY(irq) \
 244         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 245           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 246 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 247
 248 #ifdef CONFIG_X86
 249 #  define PIC_ROUTING_ENTRY(irq) \
 250         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 251           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 252 #  define ROUTING_ENTRY2(irq) \
 253         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 254 #else
 255 #  define ROUTING_ENTRY2(irq) \
 256         IOAPIC_ROUTING_ENTRY(irq)
 257 #endif
 258
 259 static const struct kvm_irq_routing_entry default_routing[] = {
 260         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 261         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 262         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 263         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 264         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 265         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 266         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 267         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 268         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 269         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 270         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 271         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 272 #ifdef CONFIG_IA64
 273         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 274         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 275         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 276         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 277         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 278         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 279         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 280         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 281         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 282         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 283         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 284         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 285 #endif
 286 };
 287
 288 int kvm_setup_default_irq_routing(struct kvm *kvm)
 289 {
 290         return kvm_set_irq_routing(kvm, default_routing,
 291                                    ARRAY_SIZE(default_routing), 0);
 292 }