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
  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->type == KVM_IRQ_ROUTING_IRQCHIP &&
 164                     e->irqchip.irqchip == irqchip &&
 165                     e->irqchip.pin == pin) {
 166                         gsi = e->gsi;
 167                         break;
 168                 }
 169
 170         hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
 171                 if (kian->gsi == gsi)
 172                         kian->irq_acked(kian);
 173 }
 174
 175 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 176                                    struct kvm_irq_ack_notifier *kian)
 177 {
 178         hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
 179 }
 180
 181 void kvm_unregister_irq_ack_notifier(struct kvm_irq_ack_notifier *kian)
 182 {
 183         hlist_del_init(&kian->link);
 184 }
 185
 186 /* The caller must hold kvm->lock mutex */
 187 int kvm_request_irq_source_id(struct kvm *kvm)
 188 {
 189         unsigned long *bitmap = &kvm->arch.irq_sources_bitmap;
 190         int irq_source_id = find_first_zero_bit(bitmap,
 191                                 sizeof(kvm->arch.irq_sources_bitmap));
 192
 193         if (irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 194                 printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
 195                 return -EFAULT;
 196         }
 197
 198         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 199         set_bit(irq_source_id, bitmap);
 200
 201         return irq_source_id;
 202 }
 203
 204 void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 205 {
 206         int i;
 207
 208         ASSERT(irq_source_id != KVM_USERSPACE_IRQ_SOURCE_ID);
 209
 210         if (irq_source_id < 0 ||
 211             irq_source_id >= sizeof(kvm->arch.irq_sources_bitmap)) {
 212                 printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
 213                 return;
 214         }
 215         for (i = 0; i < KVM_IOAPIC_NUM_PINS; i++)
 216                 clear_bit(irq_source_id, &kvm->arch.irq_states[i]);
 217         clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
 218 }
 219
 220 void kvm_register_irq_mask_notifier(struct kvm *kvm, int irq,
 221                                     struct kvm_irq_mask_notifier *kimn)
 222 {
 223         kimn->irq = irq;
 224         hlist_add_head(&kimn->link, &kvm->mask_notifier_list);
 225 }
 226
 227 void kvm_unregister_irq_mask_notifier(struct kvm *kvm, int irq,
 228                                       struct kvm_irq_mask_notifier *kimn)
 229 {
 230         hlist_del(&kimn->link);
 231 }
 232
 233 void kvm_fire_mask_notifiers(struct kvm *kvm, int irq, bool mask)
 234 {
 235         struct kvm_irq_mask_notifier *kimn;
 236         struct hlist_node *n;
 237
 238         hlist_for_each_entry(kimn, n, &kvm->mask_notifier_list, link)
 239                 if (kimn->irq == irq)
 240                         kimn->func(kimn, mask);
 241 }
 242
 243 static void __kvm_free_irq_routing(struct list_head *irq_routing)
 244 {
 245         struct kvm_kernel_irq_routing_entry *e, *n;
 246
 247         list_for_each_entry_safe(e, n, irq_routing, link)
 248                 kfree(e);
 249 }
 250
 251 void kvm_free_irq_routing(struct kvm *kvm)
 252 {
 253         __kvm_free_irq_routing(&kvm->irq_routing);
 254 }
 255
 256 static int setup_routing_entry(struct kvm_kernel_irq_routing_entry *e,
 257                                const struct kvm_irq_routing_entry *ue)
 258 {
 259         int r = -EINVAL;
 260         int delta;
 261
 262         e->gsi = ue->gsi;
 263         e->type = ue->type;
 264         switch (ue->type) {
 265         case KVM_IRQ_ROUTING_IRQCHIP:
 266                 delta = 0;
 267                 switch (ue->u.irqchip.irqchip) {
 268                 case KVM_IRQCHIP_PIC_MASTER:
 269                         e->set = kvm_set_pic_irq;
 270                         break;
 271                 case KVM_IRQCHIP_PIC_SLAVE:
 272                         e->set = kvm_set_pic_irq;
 273                         delta = 8;
 274                         break;
 275                 case KVM_IRQCHIP_IOAPIC:
 276                         e->set = kvm_set_ioapic_irq;
 277                         break;
 278                 default:
 279                         goto out;
 280                 }
 281                 e->irqchip.irqchip = ue->u.irqchip.irqchip;
 282                 e->irqchip.pin = ue->u.irqchip.pin + delta;
 283                 break;
 284         case KVM_IRQ_ROUTING_MSI:
 285                 e->set = kvm_set_msi;
 286                 e->msi.address_lo = ue->u.msi.address_lo;
 287                 e->msi.address_hi = ue->u.msi.address_hi;
 288                 e->msi.data = ue->u.msi.data;
 289                 break;
 290         default:
 291                 goto out;
 292         }
 293         r = 0;
 294 out:
 295         return r;
 296 }
 297
 298
 299 int kvm_set_irq_routing(struct kvm *kvm,
 300                         const struct kvm_irq_routing_entry *ue,
 301                         unsigned nr,
 302                         unsigned flags)
 303 {
 304         struct list_head irq_list = LIST_HEAD_INIT(irq_list);
 305         struct list_head tmp = LIST_HEAD_INIT(tmp);
 306         struct kvm_kernel_irq_routing_entry *e = NULL;
 307         unsigned i;
 308         int r;
 309
 310         for (i = 0; i < nr; ++i) {
 311                 r = -EINVAL;
 312                 if (ue->gsi >= KVM_MAX_IRQ_ROUTES)
 313                         goto out;
 314                 if (ue->flags)
 315                         goto out;
 316                 r = -ENOMEM;
 317                 e = kzalloc(sizeof(*e), GFP_KERNEL);
 318                 if (!e)
 319                         goto out;
 320                 r = setup_routing_entry(e, ue);
 321                 if (r)
 322                         goto out;
 323                 ++ue;
 324                 list_add(&e->link, &irq_list);
 325                 e = NULL;
 326         }
 327
 328         mutex_lock(&kvm->lock);
 329         list_splice(&kvm->irq_routing, &tmp);
 330         INIT_LIST_HEAD(&kvm->irq_routing);
 331         list_splice(&irq_list, &kvm->irq_routing);
 332         INIT_LIST_HEAD(&irq_list);
 333         list_splice(&tmp, &irq_list);
 334         mutex_unlock(&kvm->lock);
 335
 336         r = 0;
 337
 338 out:
 339         kfree(e);
 340         __kvm_free_irq_routing(&irq_list);
 341         return r;
 342 }
 343
 344 #define IOAPIC_ROUTING_ENTRY(irq) \
 345         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 346           .u.irqchip.irqchip = KVM_IRQCHIP_IOAPIC, .u.irqchip.pin = (irq) }
 347 #define ROUTING_ENTRY1(irq) IOAPIC_ROUTING_ENTRY(irq)
 348
 349 #ifdef CONFIG_X86
 350 #  define PIC_ROUTING_ENTRY(irq) \
 351         { .gsi = irq, .type = KVM_IRQ_ROUTING_IRQCHIP,  \
 352           .u.irqchip.irqchip = SELECT_PIC(irq), .u.irqchip.pin = (irq) % 8 }
 353 #  define ROUTING_ENTRY2(irq) \
 354         IOAPIC_ROUTING_ENTRY(irq), PIC_ROUTING_ENTRY(irq)
 355 #else
 356 #  define ROUTING_ENTRY2(irq) \
 357         IOAPIC_ROUTING_ENTRY(irq)
 358 #endif
 359
 360 static const struct kvm_irq_routing_entry default_routing[] = {
 361         ROUTING_ENTRY2(0), ROUTING_ENTRY2(1),
 362         ROUTING_ENTRY2(2), ROUTING_ENTRY2(3),
 363         ROUTING_ENTRY2(4), ROUTING_ENTRY2(5),
 364         ROUTING_ENTRY2(6), ROUTING_ENTRY2(7),
 365         ROUTING_ENTRY2(8), ROUTING_ENTRY2(9),
 366         ROUTING_ENTRY2(10), ROUTING_ENTRY2(11),
 367         ROUTING_ENTRY2(12), ROUTING_ENTRY2(13),
 368         ROUTING_ENTRY2(14), ROUTING_ENTRY2(15),
 369         ROUTING_ENTRY1(16), ROUTING_ENTRY1(17),
 370         ROUTING_ENTRY1(18), ROUTING_ENTRY1(19),
 371         ROUTING_ENTRY1(20), ROUTING_ENTRY1(21),
 372         ROUTING_ENTRY1(22), ROUTING_ENTRY1(23),
 373 #ifdef CONFIG_IA64
 374         ROUTING_ENTRY1(24), ROUTING_ENTRY1(25),
 375         ROUTING_ENTRY1(26), ROUTING_ENTRY1(27),
 376         ROUTING_ENTRY1(28), ROUTING_ENTRY1(29),
 377         ROUTING_ENTRY1(30), ROUTING_ENTRY1(31),
 378         ROUTING_ENTRY1(32), ROUTING_ENTRY1(33),
 379         ROUTING_ENTRY1(34), ROUTING_ENTRY1(35),
 380         ROUTING_ENTRY1(36), ROUTING_ENTRY1(37),
 381         ROUTING_ENTRY1(38), ROUTING_ENTRY1(39),
 382         ROUTING_ENTRY1(40), ROUTING_ENTRY1(41),
 383         ROUTING_ENTRY1(42), ROUTING_ENTRY1(43),
 384         ROUTING_ENTRY1(44), ROUTING_ENTRY1(45),
 385         ROUTING_ENTRY1(46), ROUTING_ENTRY1(47),
 386 #endif
 387 };
 388
 389 int kvm_setup_default_irq_routing(struct kvm *kvm)
 390 {
 391         return kvm_set_irq_routing(kvm, default_routing,
 392                                    ARRAY_SIZE(default_routing), 0);
 393 }