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   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 gsi)
  63 {
  64         struct kvm_irq_ack_notifier *kian;
  65         struct hlist_node *n;
  66
  67         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
  68                 if (kian->gsi == gsi)
  69                         kian->irq_acked(kian);
  70 }
  71
  72 void kvm_register_irq_ack_notifier(struct kvm *kvm,
  73                                    struct kvm_irq_ack_notifier *kian)
  74 {
  75         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
  76 }
  77
  78 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
  79 {
  80         hlist_del_init(&kian->link);
  81 }
  82
  83 /* The caller must hold kvm->lock mutex */
  84 int kvm_request_irq_source_id(struct kvm *kvm)
  85 {
  86         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
  87         int irq_source_id = find_first_zero_bit(bitmap,
  88                                 sizeof(kvm->arch.irq_sources_bitmap));
  89
  90         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
  91                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
  92                 return -EFAULT;
  93         }
  94
  95         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
  96         set_bit(irq_source_id, bitmap);
  97
  98         return irq_source_id;
  99 }
 100
 101 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 102 {
 103         int i;
 104
 105         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 106
 107         if (irq_source_id < 0 ||
 108             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 109                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 110                 return;
 111         }
 112         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 113                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 114         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 115 }
 116
 117 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 118                                     struct kvm_irq_mask_notifier *kimn)
 119 {
 120         kimn->irq = irq;
 121         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 122 }
 123
 124 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 125                                       struct kvm_irq_mask_notifier *kimn)
 126 {
 127         hlist_del(&kimn->link);
 128 }
 129
 130 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 131 {
 132         struct kvm_irq_mask_notifier *kimn;
 133         struct hlist_node *n;
 134
 135         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 136                 if (kimn->irq == irq)
 137                         kimn->func(kimn, mask);
 138 }
 139
 140 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 141 {
 142         struct kvm_kernel_irq_routing_entry *e, *n;
 143
 144         list_for_each_entry_safe(e, n, irq_routing, link)
 145                 kfree(e);
 146 }
 147
 148 void kvm_free_irq_routing(struct kvm *kvm)
 149 {
 150         __kvm_free_irq_routing(&kvm->irq_routing);
 151 }
 152
 153 int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 154                         const struct kvm_irq_routing_entry *ue)
 155 {
 156         int r = -EINVAL;
 157         int delta;
 158
 159         e->gsi = ue->gsi;
 160         switch (ue->type) {
 161         case KVM_IRQ_ROUTING_IRQCHIP:
 162                 delta = 0;
 163                 switch (ue->u.irqchip.irqchip) {
 164                 case KVM_IRQCHIP_PIC_MASTER:
 165                         e->set = kvm_set_pic_irq;
 166                         break;
 167                 case KVM_IRQCHIP_PIC_SLAVE:
 168                                 e->set = kvm_set_pic_irq;
 169                         delta = 8;
 170                         break;
 171                 case KVM_IRQCHIP_IOAPIC:
 172                                 e->set = kvm_set_ioapic_irq;
 173                         break;
 174                 default:
 175                         goto out;
 176                 }
 177                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 178                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 179                 break;
 180         default:
 181                 goto out;
 182         }
 183         r = 0;
 184 out:
 185         return r;
 186 }
 187
 188
 189 int kvm_set_irq_routing(struct kvm *kvm,
 190                         const struct kvm_irq_routing_entry *ue,
 191                         unsigned nr,
 192                         unsigned flags)
 193 {
 194         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 195         struct list_head tmp = LIST_HEAD_INIT(tmp);
 196         struct kvm_kernel_irq_routing_entry *e = NULL;
 197         unsigned i;
 198         int r;
 199
 200         for (i = 0; i < nr; ++i) {
 201                 r = -EINVAL;
 202                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 203                         goto out;
 204                 if (ue->flags)
 205                         goto out;
 206                 r = -ENOMEM;
 207                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 208                 if (!e)
 209                         goto out;
 210                 r = setup_routing_entry(e, ue);
 211                 if (r)
 212                         goto out;
 213                 ++ue;
 214                 list_add(&e->link, &irq_list);
 215                 e = NULL;
 216         }
 217
 218         mutex_lock(&kvm->lock);
 219         list_splice(&kvm->irq_routing, &tmp);
 220         INIT_LIST_HEAD(&kvm->irq_routing);
 221         list_splice(&irq_list, &kvm->irq_routing);
 222         INIT_LIST_HEAD(&irq_list);
 223         list_splice(&tmp, &irq_list);
 224         mutex_unlock(&kvm->lock);
 225
 226         r = 0;
 227
 228 out:
 229         kfree(e);
 230         __kvm_free_irq_routing(&irq_list);
 231         return r;
 232 }
 233
 234 #define IOAPIC_ROUTING_ENTRY(irq) \
 235         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 236           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 237 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 238
 239 #ifdef CONFIG_X86
 240 #define SELECT_PIC(irq) \
 241         ((irq) < 8 ? KVM_IRQCHIP_PIC_MASTER : KVM_IRQCHIP_PIC_SLAVE)
 242 #  define PIC_ROUTING_ENTRY(irq) \
 243         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 244           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 245 #  define ROUTING_ENTRY2(irq) \
 246         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 247 #else
 248 #  define ROUTING_ENTRY2(irq) \
 249         IOAPIC_ROUTING_ENTRY(irq)
 250 #endif
 251
 252 static const struct kvm_irq_routing_entry default_routing[] = {
 253         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 254         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 255         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 256         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 257         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 258         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 259         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 260         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 261         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 262         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 263         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 264         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 265 #ifdef CONFIG_IA64
 266         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 267         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 268         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 269         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 270         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 271         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 272         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 273         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 274         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 275         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 276         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 277         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 278 #endif
 279 };
 280
 281 int kvm_setup_default_irq_routing(struct kvm *kvm)
 282 {
 283         return kvm_set_irq_routing(kvm, default_routing,
 284                                    ARRAY_SIZE(default_routing), 0);
 285 }