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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
  24 #include <asm/msidef.h>
  25 #ifdef CONFIG_IA64
  26 #include <asm/iosapic.h>
  27 #endif
  28
  29 #include "irq.h"
  30
  31 #include "ioapic.h"
  32
  33 static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
  34                            struct kvm *kvm, int level)
  35 {
  36 #ifdef CONFIG_X86
  37         return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
  38 #else
  39         return -1;
  40 #endif
  41 }
  42
  43 static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
  44                               struct kvm *kvm, int level)
  45 {
  46         return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
  47 }
  48
  49 inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
  50 {
  51 #ifdef CONFIG_IA64
  52         return irq->delivery_mode ==
  53                 (IOSAPIC_LOWEST_PRIORITY << IOSAPIC_DELIVERY_SHIFT);
  54 #else
  55         return irq->delivery_mode == APIC_DM_LOWEST;
  56 #endif
  57 }
  58
  59 int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
  60                 struct kvm_lapic_irq *irq)
  61 {
  62         int i, r = -1;
  63         struct kvm_vcpu *vcpu, *lowest = NULL;
  64
  65         if (irq->dest_mode == 0 && irq->dest_id == 0xff &&
  66                         kvm_is_dm_lowest_prio(irq))
  67                 printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
  68
  69         for (i = 0; i < KVM_MAX_VCPUS; i++) {
  70                 vcpu = kvm->vcpus[i];
  71
  72                 if (!vcpu || !kvm_apic_present(vcpu))
  73                         continue;
  74
  75                 if (!kvm_apic_match_dest(vcpu, src, irq->shorthand,
  76                                         irq->dest_id, irq->dest_mode))
  77                         continue;
  78
  79                 if (!kvm_is_dm_lowest_prio(irq)) {
  80                         if (r < 0)
  81                                 r = 0;
  82                         r += kvm_apic_set_irq(vcpu, irq);
  83                 } else {
  84                         if (!lowest)
  85                                 lowest = vcpu;
  86                         else if (kvm_apic_compare_prio(vcpu, lowest) < 0)
  87                                 lowest = vcpu;
  88                 }
  89         }
  90
  91         if (lowest)
  92                 r = kvm_apic_set_irq(lowest, irq);
  93
  94         return r;
  95 }
  96
  97 static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
  98                        struct kvm *kvm, int level)
  99 {
 100         struct kvm_lapic_irq irq;
 101
 102         irq.dest_id = (e->msi.address_lo &
 103                         MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
 104         irq.vector = (e->msi.data &
 105                         MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
 106         irq.dest_mode = (1 << MSI_ADDR_DEST_MODE_SHIFT) & e->msi.address_lo;
 107         irq.trig_mode = (1 << MSI_DATA_TRIGGER_SHIFT) & e->msi.data;
 108         irq.delivery_mode = e->msi.data & 0x700;
 109         irq.level = 1;
 110         irq.shorthand = 0;
 111
 112         /* TODO Deal with RH bit of MSI message address */
 113         return kvm_irq_delivery_to_apic(kvm, NULL, &irq);
 114 }
 115
 116 /* This should be called with the kvm->lock mutex held
 117  * Return value:
 118  *  < 0   Interrupt was ignored (masked or not delivered for other reasons)
 119  *  = 0   Interrupt was coalesced (previous irq is still pending)
 120  *  > 0   Number of CPUs interrupt was delivered to
 121  */
 122 int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
 123 {
 124         struct kvm_kernel_irq_routing_entry *e;
 125         unsigned long *irq_state, sig_level;
 126         int ret = -1;
 127
 128         if (irq < KVM_IOAPIC_NUM_PINS) {
 129                 irq_state = (unsigned long *)&kvm->arch.irq_states[irq];
 130
 131                 /* Logical OR for level trig interrupt */
 132                 if (level)
 133                         set_bit(irq_source_id, irq_state);
 134                 else
 135                         clear_bit(irq_source_id, irq_state);
 136                 sig_level = !!(*irq_state);
 137         } else /* Deal with MSI/MSI-X */
 138                 sig_level = 1;
 139
 140         /* Not possible to detect if the guest uses the PIC or the
 141          * IOAPIC.  So set the bit in both. The guest will ignore
 142          * writes to the unused one.
 143          */
 144         list_for_each_entry(e, &kvm->irq_routing, link)
 145                 if (e->gsi == irq) {
 146                         int r = e->set(e, kvm, sig_level);
 147                         if (r < 0)
 148                                 continue;
 149
 150                         ret = r + ((ret < 0) ? 0 : ret);
 151                 }
 152         return ret;
 153 }
 154
 155 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 156 {
 157         struct kvm_kernel_irq_routing_entry *e;
 158         struct kvm_irq_ack_notifier *kian;
 159         struct hlist_node *n;
 160         unsigned gsi = pin;
 161
 162         list_for_each_entry(e, &kvm->irq_routing, link)
 163                 if (e->irqchip.irqchip == irqchip &&
 164                     e->irqchip.pin == pin) {
 165                         gsi = e->gsi;
 166                         break;
 167                 }
 168
 169         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
 170                 if (kian->gsi == gsi)
 171                         kian->irq_acked(kian);
 172 }
 173
 174 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 175                                    struct kvm_irq_ack_notifier *kian)
 176 {
 177         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
 178 }
 179
 180 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
 181 {
 182         hlist_del_init(&kian->link);
 183 }
 184
 185 /* The caller must hold kvm->lock mutex */
 186 int kvm_request_irq_source_id(struct kvm *kvm)
 187 {
 188         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 189         int irq_source_id = find_first_zero_bit(bitmap,
 190                                 sizeof(kvm->arch.irq_sources_bitmap));
 191
 192         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 193                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 194                 return -EFAULT;
 195         }
 196
 197         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 198         set_bit(irq_source_id, bitmap);
 199
 200         return irq_source_id;
 201 }
 202
 203 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 204 {
 205         int i;
 206
 207         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 208
 209         if (irq_source_id < 0 ||
 210             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 211                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 212                 return;
 213         }
 214         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 215                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 216         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 217 }
 218
 219 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 220                                     struct kvm_irq_mask_notifier *kimn)
 221 {
 222         kimn->irq = irq;
 223         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 224 }
 225
 226 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 227                                       struct kvm_irq_mask_notifier *kimn)
 228 {
 229         hlist_del(&kimn->link);
 230 }
 231
 232 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 233 {
 234         struct kvm_irq_mask_notifier *kimn;
 235         struct hlist_node *n;
 236
 237         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 238                 if (kimn->irq == irq)
 239                         kimn->func(kimn, mask);
 240 }
 241
 242 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 243 {
 244         struct kvm_kernel_irq_routing_entry *e, *n;
 245
 246         list_for_each_entry_safe(e, n, irq_routing, link)
 247                 kfree(e);
 248 }
 249
 250 void kvm_free_irq_routing(struct kvm *kvm)
 251 {
 252         __kvm_free_irq_routing(&kvm->irq_routing);
 253 }
 254
 255 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 256                                const struct kvm_irq_routing_entry *ue)
 257 {
 258         int r = -EINVAL;
 259         int delta;
 260
 261         e->gsi = ue->gsi;
 262         switch (ue->type) {
 263         case KVM_IRQ_ROUTING_IRQCHIP:
 264                 delta = 0;
 265                 switch (ue->u.irqchip.irqchip) {
 266                 case KVM_IRQCHIP_PIC_MASTER:
 267                         e->set = kvm_set_pic_irq;
 268                         break;
 269                 case KVM_IRQCHIP_PIC_SLAVE:
 270                         e->set = kvm_set_pic_irq;
 271                         delta = 8;
 272                         break;
 273                 case KVM_IRQCHIP_IOAPIC:
 274                         e->set = kvm_set_ioapic_irq;
 275                         break;
 276                 default:
 277                         goto out;
 278                 }
 279                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 280                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 281                 break;
 282         case KVM_IRQ_ROUTING_MSI:
 283                 e->set = kvm_set_msi;
 284                 e->msi.address_lo = ue->u.msi.address_lo;
 285                 e->msi.address_hi = ue->u.msi.address_hi;
 286                 e->msi.data = ue->u.msi.data;
 287                 break;
 288         default:
 289                 goto out;
 290         }
 291         r = 0;
 292 out:
 293         return r;
 294 }
 295
 296
 297 int kvm_set_irq_routing(struct kvm *kvm,
 298                         const struct kvm_irq_routing_entry *ue,
 299                         unsigned nr,
 300                         unsigned flags)
 301 {
 302         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 303         struct list_head tmp = LIST_HEAD_INIT(tmp);
 304         struct kvm_kernel_irq_routing_entry *e = NULL;
 305         unsigned i;
 306         int r;
 307
 308         for (i = 0; i < nr; ++i) {
 309                 r = -EINVAL;
 310                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 311                         goto out;
 312                 if (ue->flags)
 313                         goto out;
 314                 r = -ENOMEM;
 315                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 316                 if (!e)
 317                         goto out;
 318                 r = setup_routing_entry(e, ue);
 319                 if (r)
 320                         goto out;
 321                 ++ue;
 322                 list_add(&e->link, &irq_list);
 323                 e = NULL;
 324         }
 325
 326         mutex_lock(&kvm->lock);
 327         list_splice(&kvm->irq_routing, &tmp);
 328         INIT_LIST_HEAD(&kvm->irq_routing);
 329         list_splice(&irq_list, &kvm->irq_routing);
 330         INIT_LIST_HEAD(&irq_list);
 331         list_splice(&tmp, &irq_list);
 332         mutex_unlock(&kvm->lock);
 333
 334         r = 0;
 335
 336 out:
 337         kfree(e);
 338         __kvm_free_irq_routing(&irq_list);
 339         return r;
 340 }
 341
 342 #define IOAPIC_ROUTING_ENTRY(irq) \
 343         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 344           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 345 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 346
 347 #ifdef CONFIG_X86
 348 #  define PIC_ROUTING_ENTRY(irq) \
 349         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 350           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 351 #  define ROUTING_ENTRY2(irq) \
 352         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 353 #else
 354 #  define ROUTING_ENTRY2(irq) \
 355         IOAPIC_ROUTING_ENTRY(irq)
 356 #endif
 357
 358 static const struct kvm_irq_routing_entry default_routing[] = {
 359         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 360         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 361         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 362         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 363         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 364         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 365         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 366         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 367         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 368         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 369         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 370         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 371 #ifdef CONFIG_IA64
 372         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 373         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 374         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 375         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 376         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 377         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 378         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 379         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 380         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 381         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 382         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 383         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 384 #endif
 385 };
 386
 387 int kvm_setup_default_irq_routing(struct kvm *kvm)
 388 {
 389         return kvm_set_irq_routing(kvm, default_routing,
 390                                    ARRAY_SIZE(default_routing), 0);
 391 }